• 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.

• The Journal of the Korean Society for Microbiology
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• v.34 no.5
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• pp.453-459
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• 1999

Astrovirus is frequently associated with diarrhea in children. It can not be readily isolated by cell culture, and an electronmicroscope is usually used for detection of this agent. Recently in 1995 a combined method of reverse transcription-polymerase chain reaction (RT-PCR) was designed for easier detection of astrovirus, which is based on the conserved sequence in 3'-end of genomes of the 7 known serotypes of human astrovirus. As of yet there has not been any report of astrovirus data in Korea using the RT-PCR methods. The purpose of this study was to detect astrovirus incidence, severity of symptoms, seasonal variation and co infection rate with rotavirus in Korean children inpatients with diarrhea. Fecal specimens from 61 young children hospitalized with gasteroenteritis Korea from Jan. 1996 through Mar. 1997. They were examined for astroviurs infection by RT-PCR method. Results are as follows:1. Astrovirus was detected at 9.8% (6/61) from fecal specimens of children with severe diarrhea by EIA using monoclonal antibody coated plates. 2. Astorvirus was detected at 29.5% (18/61) from fecal specimens of children with severe diarrhea by RT-PCR. 3. The age of the 18 children affected by astrovirus ranged from 2 monthes to 7 years with mean of 3.0 years. 4. Mean hospital stay of the 18 children was 6.1 days. 5. Five (27.8%) astrovirus RT-PCR positive strains were confirmed in November and in December, respectively out of 18 specimens in total. 6. Astrovirus coinfection with rotavirus type G1 was confirmed in 15/16 specimens (93.8%), and with type G2 was in 1/16 specimens (6.3%).

• Clinical and Experimental Pediatrics
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• v.58 no.1
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• pp.20-27
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• 2015

Purpose: We investigated the molecular types of uropathogenic Escherichia coli (UPEC) by using conventional phylogrouping, multilocus sequence typing (MLST), and fimH genotyping. Methods: Samples of patients younger than 18 years of age were collected from the Chung-Ang University Hospital over 2 years. Conventional phylogenetic grouping for UPEC strains was performed by polymerase chain reaction (PCR). Bacterial strain sequence types (STs) were classified on the basis of the results of partial sequencing of seven housekeeping genes. In addition, we analyzed nucleotide variations in a 424-base pair fragment of fimH, a major virulence factor in UPEC. Results: Sixty-four UPEC isolates were analyzed in this study. Phylogenetic grouping revealed that group B2 was the most common type (n=54, 84%). We identified 16 distinctive STs using MLST. The most common STs were ST95 (35.9%), ST73 (15.6%), ST131 (12.5%), ST69 (7.8%), and ST14 (6.3%). Fourteen fimH allele types were identified, of which 11 had been previously reported, and the remaining three were identified in this study. f1 (n=28, 45.2%) was found to be the most common allele type, followed by f6 and f9 (n=7, 11.3% each). Comparative analysis of the results from the three different molecular typing techniques revealed that both MLST and fimH typing generated more discriminatory UPEC types than did PCR-based phylogrouping. Conclusion: We characterized UPEC molecular types isolated from Korean children by MLST and fimH genotyping. fimH genotyping might serve as a useful molecular test for large epidemiologic studies of UPEC isolates.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.317-332
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• 2004

Osteoblasts from alveolar bone may have an important role in the bone regeneration for periodontium, but their culture and characterization are not determined yet. The purpose of this study was to investigate the biological characteristics of primary explant cultured osteoblasts(PECO) from alveolar bone. Osteoblasts were isolated and cultured from alveolar socket of extracted tooth in children. To compare the characteristics, osteoblasts and gingival fibroblasts were cultured with DMEM at $37^{\circ}C$, 5% $CO_2$, l00% humidity incubator, and human fetal osteoblasts cell line(hFOB1) were cultured with DMEM at $34^{\circ}C$, 5%, $CO_2$ 100% humidity incubator. To characterize the isolated bone cells, morphologic change, cell proliferation and differentiation were measured. Morphology of PECO was small round body or cuboidal shape on inverted microscope and was similar with hFOB1. PECO became polygonal shape with stellate and had an amorphous shape at 9th passage in culture. PECO had significantly higher activity than that of gingival fibroblasts and hFOB1 in alkaline phosphatase activity. The expression of osteocalcin and bone sialoprotein in PECO was notably increased when compared with hFOB1 and gingival fibroblasts. These result indicated that PECO from alveolar bone in children has an obvious characteristics of osteoblast, maybe applied for the regeneration of bone.

• Childhood Kidney Diseases
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• v.22 no.2
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• pp.37-41
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• 2018

Purpose: Familial renal glucosuria (FRG, OMIM #233100) is a rare but relatively benign genetic condition characterized by persistent isolated glucosuria with a normal blood glucose level. We report three additional SLC5A2 mutations and examine their phenotypic and genetic characteristics in a Korean FRG cohort. We also reviewed the literature and summarized the genotypes of all Korean patients with FRG. Methods: A genetic analysis was conducted by directly sequencing all 14 exons of the SLC5A2 gene and their flanking regions in six unrelated Korean children with FRG and their family members. Novel non-synonymous single-nucleotide polymorphisms were identified and compared with known mutations that are repeatedly detected in the Korean population. Results: We found two novel mutations [c.274G>A (G92S) and c.1168C>T (L390F)] and one known [c.1382G>A (S461N)] mutation in each family and one recurrent mutation [c.1346G>A (G449D) (rs768392222)] in two pedigrees. The recurrent G449D was predicted to be "possibly damaging," with a score of 0.883 in Polyphen-2, while G92S, L390F, and S461N were predicted to be "probably damaging," with scores of 1.000, 0.999, and 0.996, respectively. Conclusions: Two novel, one previously reported, and one recurrent mutation were identified in six Korean FRG pedigrees as causative mutations of renal glucosuria. Sequence variations in the SLC5A2 gene were frequently detected in children with persistent isolated glucosuria. A long-term follow-up of this FRG cohort is needed to understand how these specific SGLT2 mutations impair kidney function and energy homeostasis.

• Korean Journal of Microbiology
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• v.9 no.2
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• pp.86-93
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• 1971

Escherichiae-like organisms were isolated from rectal specimens of 56 children who were either in preschool age or in elementary school. The isolated strains were subjected to tests to screen enteropathogens producing heat-labile enterotoxin and susceptibility test to various antibiotics by disc diffusion method on agar plates. Production of heat-labile enterotoxin by the strains was assyed in the sensitive and reproducible cultured adrenal tumor cell system. The assay was sterodogenesis of the cell in the presence of heat-labile enterotoxin. Among 56 strains, gave positive reaction in the test of toxin production. This meant that about 10% of the children population objected to the study harbored the toxigenic strain of enteropathogenes. Some of these toxigenic strains were resistant to the antibiotics employed in the test. This study suggested that considerable population in Korea may harbor entertoxigenic E. coli as a part of intestinal normal flora. The toxigenic strains which are resistant to antibiotics may bring issue of public health in the future.

• Advances in pediatric surgery
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• v.4 no.2
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• pp.137-143
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• 1998

Intramuscular injection(IM) into the gluteal muscles is a common route of medication, but may lead to complications. A retrospective review of 32 patients who required surgical treatment for local complications of buttock injections in children was made at the Taegu Fatima Hospital during a seven-year nine-month period (March 1990 to December 1997). Local complications included acute inflammation, cellulitis and abscess(71.9 %), and fat necrosis(21.9 %), and injection granuloma(6.2 %). Over the half of injections were on the upper and outer quadrant of the buttock, but the other 43.7 % were in the upper and inner or lower and outer quadrant which are considered unsuitable sites for intramuscular injection. The majority of complications developed within fat tissue(90.6 %) rather than within muscle(9.4 %). Two-thirds of the patients were under 2 years of age, this suggests that it is technically difficult to accurately administer IM injections in small children because muscle mass is smaller compared to subcutaneous. In addition subcutaneous fat is more susceptible to chemical irritation. Staph. aureus was the predominant organism, isolated in 84.6 % of the patients with abscesses. Treatment consisted of needle aspiration, incision and drainage, curettage, or surgical excision. In conclusion, the major factor that contributes to complications following IM of the buttock appears to be the inadvertent intrafat rather than of IM injection. Accurate injection into the muscles based on a knowledge of pelvic anatomy as well as the potential complications is necessary to prevent complications.

• Child Health Nursing Research
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• v.1 no.1
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• pp.47-58
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• 1995

This study was performed to test the validity and reliability of the Health Self-Determinism Index for Children(HSDI-C), an instrument designed to measure dimensions and strength of motivation in health behavior, to improve the applicability of the tool through application to the various samples. The convenient sample of 148 (boys=75, girls=72 third grade=42, fourth grade=22, fifth grade=32, sixth grade=52 : Caucasian=72, Asian=30, African=19) comprised the children at a chatholic elementary school in Chicago. The children completed English version of HSDI-C from December 5th, 1994 to January l0th, 1995. The findings were as follows : 1. Four factors of HSDI-C were isolated through the principal component analysis and oblique rotation, and explained 48% of the variance in total score. Low correlations among four factors were anticipated because each factor contributed uniquely, All items of the tool loaded above .30 on one of 4 factors. But items loaded on each factor in this study were very different from those in the previous studies. 2. Cronbach's alpha coefficient for internal consistency was .81 for the total items and .57∼ .81 for 4 subscales. 3. The differences of HSDI-c mean scores between boys and girls and that of among races were not statistically signifcant, but the mean score of girls and the Caucasian were relatively high. The total mean score of the scale was highest at the 3rd grade, decreased at the 4th or 5th grade, and reincreased at the 6th grade. The trend of mean score of four subscales was similar to that of total mean score. According to the results, suggested below : 1. The items loaded on each factor in this study were very different from those in the previous studies. To clear away the problem of the conceptual confusion, HSDI-C needs to be performed to various and large samples. 2. Unexpectedly, the HSDI-C mean score decreased at middle school age. A longitudinal study will be helpful to search for the change trend of the intrinsic motivation. 3. To improve the applicabilty of the HSDI-C, various reliability and validity test methods besides factor analysis or internal consistency are recommended.

• Childhood Kidney Diseases
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• v.10 no.2
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• pp.192-200
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• 2006

Purpose : This study was performed to identify longitudinal changes in the prevalence of organisms isolated from urinary tract infection(UTI) and in the pattern of Escherichia coli susceptibility to antibiotics during the past 10 years in children with UTI. Methods : We performed a retrospective study of a total of 192 urine cultures from children with UTI in the Department of Pediatrics, Seoul Adventist Hospital over two periods(1st: 1995-2000, 2nd:2001-2005). Antimicrobial susceptibility of the isolates was compared between the two groups. Results : The pathogens of UTI in the two groups were similar. In the first period, E. coli was the leading uropathogen(66.2%) followed by Klebsiella pneumoniae(7.8%), Enterobacter cloacae(6.5%), and others(19.5%). In the second period, E. coli was the leading uropathogen(67%) followed by K. pneumoniae(12.2%), E. cloacae(3.5%), Enterobacter aerogenes(3.5%), and others(13.8%). The susceptibility pattern of E. coli to amoxicillin/clavulanate(87.5%, 81.0%) did not present any statistically significant difference between the two periods(P>0.05). The susceptibility of E. coli to TMP/SMX(52.4%, 50.0%) was still low with no significant difference between the two periods(P>0.05). Conclusion : Our results suggest that the use of amoxicillin/clavulanate is still an excellent therapeutic option in children with UTI. The low rate of susceptibility to TMP/SMX against uropathogens suggest that TMP/SMX may be reevaluated as the first-line therapeutic drug for UTI.

• Clinical and Experimental Pediatrics
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• v.60 no.7
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• pp.221-226
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• 2017

Purpose: Escherichia coli sequence type (ST) 131, a multidrug-resistant clone causing extraintestinal infections, has rapidly become prevalent worldwide. However, the epidemiological and clinical features of pediatric infections are poorly understood. We aimed to explore the characteristics of ST131 Escherichia coli isolated from Korean children with urinary tract infections. Methods: We examined 114 uropathogenic E. coli (UPEC) isolates from children hospitalized at Chung-Ang University Hospital between 2011 and 2014. Bacterial strains were classified into STs by partial sequencing of seven housekeeping genes (adk, fumC, gyrB, icd, mdh, purA, and recA). Clinical characteristics and antimicrobial susceptibility were compared between ST131 and non-ST131 UPEC isolates. Results: Sixteen UPEC isolates (14.0%) were extended-spectrum ${\beta}-lactamase$ (ESBL)-producers; 50.0% of ESBL-producers were ST131 isolates. Of all the isolates tested, 13.2% (15 of 114) were classified as ST131. There were no statistically significant associations between ST131 and age, sex, or clinical characteristics, including fever, white blood cell counts in urine and serum, C-reactive protein, radiologic abnormalities, and clinical outcome. However, ST131 isolates showed significantly lower rates of susceptibility to cefazolin (26.7%), cefotaxime (40.0%), cefepime (40.0%), and ciprofloxacin (53.3%) than non-ST131 isolates (65.7%, 91.9%, 92.9%, and 87.9%, respectively; P<0.001 for all). ESBL was more frequently produced in ST131 (53.3%) than in non-ST131 (8.1%) isolates (P<0.01). Conclusion: ST131 E. coli isolates were prevalent uropathogens in children at a single medical center in Korea between 2011 and 2014. Although ST131 isolates showed higher rates of antimicrobial resistance, clinical presentation and outcomes of patients were similar to those of patients infected with non-ST131 isolates.