1.Molecular Epidemiologic Study of Streptococcus pyogenes Analyzed by T protein Serotyping and Pulsed Field Gel Elecrophoresis(PFGE) in Normal Children.
Jin Ah SON ; Don Hee AHN ; Kyu Jam HWANG ; Young Hee LEE ; Sung Ho CHA
Journal of the Korean Pediatric Society 2000;43(10):1330-1342
PURPOSE: In this study we tried to look at the spreading, duration of colonization, and acquisition of new streptococci which were obtained in one geographical area, as well as the bacteriologic and molecular epidemiology of normal school children carrying group A streptococci and their clonal relationship through the combined application of the serotype of T antigen and Pulsed Field Gel Electrophoresis(PFGE). METHODS: A total of 88 strains of group A streptococci were isolated from 396 normal school children. All isolates were classified in groups by Streptex and serotyped by T. agglutination. Restriction enzyme digestion of DNA was taken using Sma I. DNA fragments were separated by PFGE. RESULTS: A total of 33 strains were allocated their epidemiologic characteristics. Four out of 33 strains were not restricted by enzyme(Sma I). Twenty nine strains out of 33 strains showed 12 subtypes with 8-12 fragments between 40kbp and 500kbp of DNA fragments on PFGE. Eight strains of NT and T6 war same fragment patterns on PFGE, respectively. Three strains out of 4 strains of T8/25 were not restricted and the other one showed different, unique patterns. One strain out of 8 stains of T12 was not restricted, and the others were classified as 5 different subtypes. Two strains of Tl were different patterns from each other, and 2 strains of T4 showed the samefragment pattern CONCLUSION: T serotypes with PFGE will be useful as a screening and molecular epidemiologic method in a country where anti-M antisera is not available, after recognizing the advantages and disadvantages of M and T serotyping.
Agglutination
;
Antigens, Viral, Tumor
;
Child*
;
Colon
;
Coloring Agents
;
Digestion
;
DNA
;
Epidemiologic Methods
;
Epidemiologic Studies*
;
Humans
;
Immune Sera
;
Mass Screening
;
Molecular Epidemiology
;
Serotyping*
;
Streptococcus pyogenes*
;
Streptococcus*
2.The Relationship Between Hippuric Acid in Blood Plasma and Toluene Concentration in the Air of Workplace.
Cheon Hyun HWANG ; Won Jin LEE ; Soung Hoon CHANG ; Hyoung Ah KIM
Korean Journal of Preventive Medicine 2000;33(1):45-50
OBJECTIVES: This study was undertaken to evaluate correlation between the levels of hippuric acid in blood plasma (HAP) and those of toluene concentration in the workplace air. METHODS: Study subjects were composed of two groups; 21 workers who were occupationally exposed to toluene and 25 rural-area residents who were not exposed to any known occupational toluene source, as an exposed group and a reference group, respectively. Mean age and work duration of the exposed was 42 years and five years, respectively. Mean age of the reference was 42 years. To determine toluene concentrations in the workplace air, air sampling has been conducted for more than six hours using a personal sampler, and analyzed by a gas chromatography-flame ionization detector. Concentrations of hippuric acid in biological samples were determined by a high performance liquid chromatography-ultraviolet detector. RESULTS: Geometric mean(geometric standard deviation) of HAP and hippuric acid in urine(HAU) for the exposed was 1.39(2.21) mg/L and 2.77(1.46) g/L, respectively, which were significantly different from those of the reference [HAP, 0.45(2.94); HAU, 0.37(0.45)]. Toluene concentration in the workplace air was 86.92(range: 45.18~151.23) ppm. The level of HAP or HAU was significantly correlated (r=0.70 and r=0.63, respectively) with that of toluene in the workplace air. The estimated regression equation was logHAP(mg/L)=-3.60+1.93 log(toluene, ppm) or logHAU(g/L)=-0.85+0.67 log(toluene, ppm). The magnitude of correlation was further enhanced when analyzing relationship between toluene concentrations lower than 100 ppm and its corresponding HAP levels. CONCLUSION: Overall, plasma hippuric acid levels were well correlated with toluene concentrations in the workplace air, and a statistically significant correlation was observed for the samples with toluene concentration lower than 100 ppm.
Chromatography, High Pressure Liquid
;
Humans
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Occupations
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Plasma*
;
Toluene*
3.Re-Assessment of Applicability of Greulich and Pyle-Based Bone Age to Korean Children Using Manual and Deep Learning-Based Automated Method
Jisun HWANG ; Hee Mang YOON ; Jae-Yeon HWANG ; Pyeong Hwa KIM ; Boram BAK ; Byeong Uk BAE ; Jinkyeong SUNG ; Hwa Jung KIM ; Ah Young JUNG ; Young Ah CHO ; Jin Seong LEE
Yonsei Medical Journal 2022;63(7):683-691
Purpose:
To evaluate the applicability of Greulich-Pyle (GP) standards to bone age (BA) assessment in healthy Korean children using manual and deep learning-based methods.
Materials and Methods:
We collected 485 hand radiographs of healthy children aged 2–17 years (262 boys) between 2008 and 2017. Based on GP method, BA was assessed manually by two radiologists and automatically by two deep learning-based BA assessment (DLBAA), which estimated GP-assigned (original model) and optimal (modified model) BAs. Estimated BA was compared to chronological age (CA) using intraclass correlation (ICC), Bland-Altman analysis, linear regression, mean absolute error, and root mean square error. The proportion of children showing a difference >12 months between the estimated BA and CA was calculated.
Results:
CA and all estimated BA showed excellent agreement (ICC ≥0.978, p<0.001) and significant positive linear correlations (R2 ≥0.935, p<0.001). The estimated BA of all methods showed systematic bias and tended to be lower than CA in younger patients, and higher than CA in older patients (regression slopes ≤-0.11, p<0.001). The mean absolute error of radiologist 1, radiologist 2, original, and modified DLBAA models were 13.09, 13.12, 11.52, and 11.31 months, respectively. The difference between estimated BA and CA was >12 months in 44.3%, 44.5%, 39.2%, and 36.1% for radiologist 1, radiologist 2, original, and modified DLBAA models, respectively.
Conclusion
Contemporary healthy Korean children showed different rates of skeletal development than GP standard-BA, and systemic bias should be considered when determining children’s skeletal maturation.
4.Prediction of the human in vivo antiplatelet effect of S- and R-indobufen using population pharmacodynamic modeling and simulation based on in vitro platelet aggregation test
Yook Hwan NOH ; Sungpil HAN ; Sangmin CHOE ; Jin Ah JUNG ; Jin Ah JUNG ; Ae Kyung HWANG ; Hyeong Seok LIM
Translational and Clinical Pharmacology 2018;26(4):160-165
Indobufen (Ibustrin®), a reversible inhibitor of platelet aggregation, exists in two enantiomeric forms in 1:1 ratio. Here, we characterized the anti-platelet effect of S- and R-indobufen using response surface modeling using NONMEM® and predicted the therapeutic doses exerting the maximal efficacy of each enantioselective S- and R-indobufen formulation. S- and R-indobufen were added individually or together to 24 plasma samples from drug-naïve healthy subjects, generating 892 samples containing randomly selected concentrations of the drugs of 0–128 mg/L. Collagen-induced platelet aggregation in platelet-rich plasma was determined using a Chrono-log Lumi-Aggregometer. Inhibitory sigmoid I(max) model adequately described the anti-platelet effect. The S-form was more potent, whereas the R-form showed less inter-individual variation. No significant interaction was observed between the two enantiomers. The anti-platelet effect of multiple treatments with 200 mg indobufen twice daily doses was predicted in the simulation study, and the effect of S- or R-indobufen alone at various doses was predicted to define optimal dosing regimen for each enantiomer. Simulation study predicted that 200 mg twice daily administration of S-indobufen alone will produce more treatment effect than S-and R-mixture formulation. S-indobufen produced treatment effect at lower concentration than R-indobufen. However, inter-individual variation of the pharmacodynamic response was smaller in R-indobufen. The present study suggests the optimal doses of R-and S-enantioselective indobufen formulations in terms of treatment efficacy for patients with thromboembolic problems. The proposed methodology in this study can be applied to the develop novel enantio-selective drugs more efficiently.
Blood Platelets
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Colon, Sigmoid
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Healthy Volunteers
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Humans
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In Vitro Techniques
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Plasma
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Platelet Aggregation
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Platelet-Rich Plasma
;
Treatment Outcome
5.Application of the postnatal urinary tract dilation classification system to predict the need for surgical intervention among neonates and young infants
Jisun HWANG ; Pyeong Hwa KIM ; Hee Mang YOON ; Sang Hoon SONG ; Ah Young JUNG ; Jin Seong LEE ; Young Ah CHO
Ultrasonography 2023;42(1):136-146
Purpose:
The aim of this study was to validate the postnatal urinary tract dilation (UTD) classification system by correlating it with the need for surgical intervention.
Methods:
Young infants who underwent ultrasound (US) examinations for prenatal hydronephrosis were retrospectively identified. The kidney units (KUs; right, left, or bilateral) were graded from UTD P0 (very low risk) to P3 (high risk) based on seven US criteria from the UTD system. Surgery-free survival curves were constructed using the Kaplan-Meier method. Univariable and multivariable Cox proportional-hazards regression analysis clustered by patients was performed. Interobserver agreement was analyzed using the weighted kappa coefficient.
Results:
In total, 504 KUs from 336 patients (mean age, 18.3±15.9 days; range, 1 to 94 days; males, n=276) were included, with a median follow-up of 24.2 months. Fifty-eight KUs underwent surgical intervention. Significant differences were observed among the Kaplan-Meier curves stratified into UTD groups (P<0.001). The presence of anterior-posterior renal pelvic diameter ≥15 mm (hazard ratio [HR], 8.602; 95% confidence interval [CI], 1.558 to 43.065), peripheral calyceal dilation (HR, 8.190; 95% CI, 1.558 to 43.065), ureteral dilation (HR, 2.619; 95% CI, 1.274 to 5.380), parenchymal thickness abnormality (HR, 3.371; 95% CI, 1.574 to 7.223), bladder abnormality (HR, 12.209; 95% CI, 3.616 to 41.225) were significantly associated with the occurrence of surgery. The interobserver agreement was moderate to almost perfect agreement for US features (κ=0.564-0.898) and substantial for final UTD grades (κ=0.716).
Conclusion
The UTD classification system is reliable and appropriately stratifies the risk of surgical intervention.
6.A Case of Chronic Idiopathic Pseudo-Obstruction Caused by a Degenerative.
Jin Ah KIM ; Je Hyung KIM ; Ho Geun HWANG ; Sun Ho AHN
Journal of the Korean Society of Coloproctology 1997;13(4):637-642
Intestinal pseudo-obstruction is characterized by symptoms and signs of mechanical bowel obstruction in the abscence of an occluding lesion of the intestinal lumen. The chronic forms of intestinal pseudo-obstruction are separated into primary and secondary in according to the underlying disorders. primary or chronic idiopathic intestinal pseudo-obstruction(CIIP) is not associated with systemic illness and a progressive nature with relapses and remissions. Since Dyer described the rare histologic subtype of idiopathic pseudo-obstruction, the primary abnormality is in the myenteric plexus of the bowel at first in 1969, only few cases are reported. We report a case of CIIP caused by degeneration of myenteric plexus of the colon and he was successfully treated with surgical management.
Colon
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Intestinal Pseudo-Obstruction
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Myenteric Plexus
;
Recurrence
7.The study on the development of relative value in medical treatment of the oral and maxillofacial surgery.
Gin Ah SONG ; Kyung Won BAEK ; Jong Min HWANG ; Soon Yong YU ; Jin Young CHOI
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2006;32(4):334-347
The aim of this study is to evaluate the reasonableness of the medical fee on oral and maxillofacial surgery field according to surgeon's opinions and actual conditions. The medical fee has significant influence on hospital income, the supply and distribution of medical manpower, quality and facilities of medical services. Questionnaire survey was sent to 86 oral and maxillofacial surgeons who worked more than 3 years in general hospital. Among them, 25 doctors replied the 109 answers survey and the average of treatment time and physician work relative value on each category was calculated. And the health insurance cost (that has been applied since 2003) was compared with the questionnaire results. And finally we investigated items that health insurance system did not include in oral and maxillofacial field but actually performed in oral and maxillofacial surgery clinic. The result was that the medical fee did not properly reflect physician work relative value of actual treatments. In case of complicated extraction, work relative value needed 3.5 times enhancement of present value. For simple impacted tooth extraction 1.8 times, for impacted tooth extraction including odontomy 1.7 times, and for fully impacted tooth more than 2/3 of it located into the alveolar bone, 1.8 times enhancement needed. In respect of the present physician work relative value, hemimandibulectomy with neck lymph node dissection for the malignancy is appropriated as 3.3 times of open reduction and internal fixation for the mandibular fracture, but the questionnaire result showed 25 times discrepancy. In conclusion, this research shows the need for intervention that health insurance included items and legal relative medical value must act in union with treatment in clinic to reduce the imbalance between them.
Current Procedural Terminology
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Fees, Medical
;
Hospitals, General
;
Insurance, Health
;
Lymph Node Excision
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Mandibular Fractures
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Mandibular Osteotomy
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Neck
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Surveys and Questionnaires
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Surgery, Oral*
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Tooth, Impacted
8.A Case of Complete Recovery from Late Insidious Type of Acute Phosphate Nephropathy.
Choong Hwan KWAK ; Ha Yeon PARK ; Yae Rim KIM ; Jin Hyuk PAEK ; Eun Ah HWANG ; Sung Bae PARK ; Seungyeup HAN
Korean Journal of Medicine 2014;86(4):505-509
The widespread use of colonoscopy for early detection of colorectal pathology has increased the use of osmotic laxatives for colonic cleansing. Among these, oral sodium phosphate preparations can cause renal insufficiency through the development of acute phosphate nephropathy. Acute phosphate nephropathy can be distinguished as early symptomatic and late insidious patterns. Patients whose presentation is insidious are easily overlooked and can progress to chronic kidney disease. We report a case of complete recovery from the late insidious type of acute phosphate nephropathy.
Colon
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Colonoscopy
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Humans
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Laxatives
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Pathology
;
Renal Insufficiency
;
Renal Insufficiency, Chronic
;
Sodium
10.In vitro Neural Cell Differentiation of Genetically Modified Human Embryonic Stem Cells Expressing Tyrosine Hydroxylase.
Hyun Ah SHIN ; Eun Young KIM ; Keum Sil LEE ; Hwang Yoon CHO ; Yong Sik KIM ; Won Don LEE ; Sepill PARK ; Jin Ho LIM
Korean Journal of Fertility and Sterility 2004;31(1):67-74
OBJECTIVE: This study was to examine in vitro neural cell differentiation pattern of the genetically modified human embryonic stem cells expressing tyrosine hydroxylase (TH). MATERIALS AND METHODS: Human embryonic stem (hES, MB03) cell was transfected with cDNAs cording for TH. Successful transfection was confirmed by western immunoblotting. Newly transfected cell line (TH#2/MB03) was induced to differentiate by two neurogenic factors retinoic acid (RA) and b-FGF. Exp. I) Upon differentiation using RA, embryoid bodies (EB, for 4 days) derived from TH#2/MB03 cells were exposed to RA (10-6 M)/AA (5x10-2 mM) for 4 days, and were allowed to differentiate in N2 medium for 7, 14 or 21 days. Exp. II) When b-FGF was used, neuronal precursor cells were expanded at the presence of b-FGF (10 ng/ml) for 6 days followed by a final differentiation in N2 medium for 7, 14 or 21 days. Neuron differentiation was examined by indirect immunocytochemistry using neuron markers (NF160 & NF200). RESULTS: After 7 days in N2 medium, approximately 80% and 20% of the RA or b-FGF induced Th#2/MB03 cells were immunoreactive to anti-NF160 and anti-NF200 antibodies, respectively. As differentiation continued, NF200 in RA treated cells significantly increased to 73.0% on 14 days compared to that in b-FGF treated cells (53.0%, p<0.05), while the proportion of cells expressing NF160 was similarly decreased between two groups. However, throughout the differentiation, expression of TH was maintained (~90%). HPLC analyses indicated the increased levels of L-DOPA in RA treated genetically modified hES cells with longer differentiation time. CONCLUSION: These results suggested that a genetically modified hES cells (TH#2/MB03) could be efficiently differentiated in vitro into mature neurons by RA induction method.
Antibodies
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Blotting, Western
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Cell Differentiation*
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Cell Line
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Chromatography, High Pressure Liquid
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DNA, Complementary
;
Embryoid Bodies
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Embryonic Stem Cells*
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Humans*
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Immunohistochemistry
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Levodopa
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Neurons
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Transfection
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Tretinoin
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Tyrosine 3-Monooxygenase*
;
Tyrosine*