• Radiation Oncology Journal
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• v.19 no.3
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• pp.205-210
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• 2001

Purpose : This study tried to evaluate the effectiveness of combined treatment using radiation therapy and concurrent cisplatin as a radiosensitizer in the management of locally advanced head and neck cancer. Materials and methods : From January 1995 to August 1998, 29 evaluable patients with locally advanced head & neck cancels (AJCC stage $II\~IV$) were received curative radiation therapy $(total\;70\~75.6\;Gy/35\~42\;fractions,\;1.8\~2\;Gy/fraction)$ and concurrent cisplatin chemotherapy ($100\;mg/m^2$, D1, D22, D43). The neck dissections were peformed for residual lymphadenopathy. Follow-up ranged from 5 to 55 months (median 24 months). Results : Twenty-one $(72.4\%)$ patients achieved clinical complete responses. The partial response and minimal response rates were $17.2\%\;and\;10.4\%$, respectively. Locoregional failure rate was $27.6\%$, and included 6 patients with local failures, 4 patients with regional failures, and 2 patients with combined local and regional failures. Four of 29 patients $(13.8\%)$ developed distant metastasis. The disease free survival rate at 3 years was $60\%$. Nasopharyngeal primary tumors or complete responders showed significantly higher disease free survival rate. The grade 3 mucositis and nausea/vomiting was noted in $34.5\%$, respectively. Major prolongation of radiation therapy duration was inevitable in three patients. Twenty-one patients $(72.4\%)$ completed 3 courses of cisplatin and 5 patients received 2 courses of cisplatin. Three patients received only one course of cisplatin due to nephrotoxicity and neurotoxicity, and then changed to 5-FU regimen. Conclusions : Concurrent cisplatin-radiation therapy in locally advanced head and neck cancer showed high response rate, reasonable locoregional control, and survival rate. As expected, acute toxicities were increased, but compliance to treatment was acceptable. Assessment of the effect of the combination in this setting requires further accrual and follow-up.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.425-431
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• 1998

Purpose : We retrospectively analyzed the impact of subpleural lesions of early stage non-small cell lung cancer on the patterns of failure to support selection of postoperative adjuvant therapy. Methods and Materials : The study included 91 patients who underwent surgery for early stage non-small cell lung cancer at Dong-A University Hospital from Dec 1990 to Sep 1996. Twenty five patients were excluded due to postoperative mortality (four patients, 4.4$\%$) and stage III (21 patients). Of 66 patients, 22 patients were subpleural lesions (15 patients in stage I, and seven patients in stage II). Postoperative adjuvant radiation therapy was given to seven patients with T2Nl disease. The median follow-up duration was 29.5 months (range; 8-84 months). Results : The overall survival rate was 69.5$\%$ at 3 years. For all patients who presented with (22 patients) and without (44 patients) subpleural lesions, 3-year overall survival rates were 35.5$\%$ and 84.6$\%$, respectively (p=0.0017). For stage I patients who presented with (15 patients) and without (29 patients) subpleural lesions, 3-year overall survival rates were 33.1$\%$ and 92.3$\%$, respectively (p=0.001). For stage II patients who presented with (7 patients) and without (15 patients) subpleural lesions, 3-year overall survival rates were 53.3$\%$ and 45.7$\%$, respectively (p=0.911). For patients with T2N0 disease (34 patients) who presented with (11 patients) and without (23 patients) subpleural lesions, 3-year overall survival rates were 27.3$\%$ and 90.3$\%$, respectively (p=0.009). Conclusion : These observations suggest that the subpleural lesion play an important role as a prognostic factor for early stage non-small cell lung cancer. Especially for T2N0 disease, patients with subpleural lesions showed significantly lower survival rate than those without that.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.441-446
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• 1998

Purpose : The incidence of esophageal carcinoma is increasing. Radical surgery is the treatment of choice, but large proportion of the esophageal cancer patients are with unresectable disease at the time of initial diagnosis, so radiation therapy has been the major treatment modality. We carried out retrospective analysis to see the outcome and prognostic factors of radiation therapy alone for esophageal carcinoma. Methods and Materials : From June of 1979 through December 1992, 289 patients with esophageal carcinoma were treated with radiation therapy alone at Department of Therapeutic Radiology, Seoul National University Hospital. Of these patients, 84 patients were excluded as they were ineligible for the current analyses. Twenty-two patients had distant metastasis other than supraclavicular lymph node metastasis, 52 patients received less than 45 Gy, and 10 patient were lost from follow-up. Therefore 205 patients constituted the base population of this study. According to AJCC s1aging system, there were 2 patients with stage 1, 104 with stage IIA, 26 with stage IIB, 48 with stage III, and 25 with stage IV Radiation dose ranged from 4500 cGy to 6980 cGy with median dose of 5940 cGy. Follow-up period of the alive patients ranged from 77 to 180 months. Results : The Median survival period of all the patients was II months and the 2-, 5-, and 10-year overall survival rates were 22.4$\%$, 10.2$\%$ and 5.3$\%$, respectively. Most of the failures were local recurrences. Of 169 failures, 134 had local failure as a component and 111 had local recurrence only. The Lymph node was most common distant metastatic site and the next was the lung. The stage, T-stage, N-stage, functional status, tumor size, and aim of treatment were statistically significant prognostic factors for survival by univariate analyses. But only tumor size and N-stage were significant by multivariate analyses. Conclusion : We could get 10.2$\%$ of 5 year survival rate and 5.3$\%$ of 10 year survival rate with radiation therapy alone. The size of tumor and N-stage were statistically significant prognostic factors for survival on multivariate analyses.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.109-116
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• 2011

Purpose : Pneumococcus is one of the most important causes of invasive infection through the childhood period. In January 2008, the Clinical and Laboratory Standards Institute (CLSI) published revised penicillin breakpoints for Streptococcus pneumoniae and penicillin susceptibility rates of S. pneumoniae increased in Korea. This study was performed to determine the probability of oral amoxicillin for the empirical treatment achieving bactericidal exposure against pneumococcus using pharmacodynamics model. Methods : Twenty-three isolates of pneumococci were subjected to determine minimum inhibitory concentration (MIC) for ${\beta}$-lactams and macrolide. For the ${\beta}$-lactams, exposure of fT >MIC (time that free drug concentrations remain above the MIC) for 50% of the administration interval have determined the probability of target attainment (PTA), and regimens that had a PTA >90% were considered optimal. An analysis was performed by applying MIC of 23 isolates to a 5000-patient Monte Carlo simulation model. Results : Among 23 isolates from healthy children, 7 (30.4%) isolates were MIC ${\leq}$1.0 ${\mu}g$/mL and 19 (82.6%) were MIC ${\leq}$2 ${\mu}g$/mL for amoxicillin. Amoxicillin 40 mg/kg/day achieved PTA >90% at MIC ${\leq}$1.0 ${\mu}g$/mL but PTA decreased to 52% at MIC 2 ${\mu}g$/mL, whereas amoxicillin 90 mg/kg/day can predict 97% of PTA at MIC 2 ${\mu}g$/mL. Overall, oral amoxicillin 90 mg/ kg/day for the empirical treatment against pneumococcus can expect more successful response in Korean children. Conclusion : Considering the resistantce pattern of pneumococci in Korean children, we estimate that oral amoxicillin 90 mg/kg/day will provide a pharmacodynamic advantage for the empirical treatment against pneumococcus. And low dose amoxicillin or macrolide are expected to have higher chance of treatment failure than high dose oral amoxicillin.

• Childhood Kidney Diseases
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• v.7 no.2
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• pp.181-188
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• 2003

Purpose : Vesicoureteral reflux(VUR) is known to be the main cause of childhood hypertension and renal failure. Knowing its familial occurrence, we determined the incidence of VUR and renal scar in asymptomatic siblings of Korean patients with primary VUR Methods : A total of 50 siblings from 37 index patients were included. Voiding cystourethro-graphy(VCUG) and renal scintigraphy using $^{99m}Tc-DMSA$ were peformed in these siblings from June, 1994 to May, 2001, Index patients were classified into two groups according to the presence of VUR in their siblings, and the clinical factors of the index patients such as age, sex, grade of reflux and renal cortical defect were compared between the groups. Results : Among the 50 siblings, VUR were found in 8(16%) and renal cortical defects were detected in 8(16%) siblings respectively. The incidence of renal cortical defects was 87.5%(7 out of 8) in the VUR(+) siblings. There was a case of VUR(-) cortical defect in one sibling, presumed as a scar from an old VUR. There was no relationship among age, sex, grade of reflux and renal cortical defect of the index patient to the presence of VUR in siblings. Conclusion : This study confirmed a significant incidence of VUR(16%) and renal cortical defects(16%) in the asymptomatic siblings of patients with primary VUR in Korea. It Is resonable to recommend screening studies to the siblings of patients with VUR for the early detection and prevention of probable reflux nephropathy. (J K orean Soc Pediatr Nephrol 2003;7:181-188)

• Journal of Genetic Medicine
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• v.4 no.1
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• pp.72-79
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• 2007

Purpose : Glycogen storage disease type III (GSD-III) is a rare autosomal recessive disorder of glycogen metabolism. The affected enzyme, amylo-1,6-glucosidase, 4-alpha-glucanotransferase (AGL, glycogen debranching enzyme), is responsible for the debranching of the glycogen molecule during catabolism. The disease shows clinical and biochemical heterogeneity, reflecting genotype-phenotype heterogeneity among different patients. In this study, we aim at analyzing mutations of the AGL gene in three unrelated Korean GSD-III patients, and characterizing their clinical and laboratory findings. Methods : We characterized the clinical features of three unrelated Korean GSD-III patients by biochemical, histological and imaging studies. The 35 exons and part of exon-intron boundaries of AGL were analyzed by direct sequencing using genomic DNA extracted from the peripheral leukocytes of patients. Results : Diverse clinical features were observed in these patients including hepatomegaly (all patients), seizures (patient 2), grow th failure (patients 1 and 2), hyperlipidemia (patients 1 and 3), raised transaminase and creatine kinase concentrations (all patients), and mild cardiomyopathy (patient 2). Liver transplantation w as performed in patient 2 due to progressive hepatic fibrosis. A dministration of uncooked corn starch maintained normoglycemia and improved biochemical and growth profiles. DNA sequence analysis revealed mutations in 5 out of 6 alleles. Patient 1 was a compound heterozygote of c.1282 G>A (p.R428K) and c.1306delA (p.S603PfsX6), patient 2 had c.1510_1511insT (p.Y 504L fsX 10), and patient 3 had c.3416 T >C (p.L 1139P) and c.1735+1 G>T (p.Y 538_R578delfsX 4) mutations. A part from the p.R428K mutation, the 4 other substitutions identified w ere nov el. Conclusion : GSD-III patients display variable phenotypic characteristics resembling those of GSD-Ia. Molecular defects in the AGL gene of Korean GSD-III patients are genetically heterogeneous.

• Journal of the Korean GEO-environmental Society
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• v.22 no.10
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• pp.21-29
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• 2021

Most concrete gravity-type dams in and out of the country were constructed by column method to control cracks caused by concrete hydration heat generated during construction, resulting in a certain level of leakage after impoundment through various causes, such as contraction joints and construction joints. However, due to the characteristics of concrete structures that shrink and expand according to temperature, concrete dams have vertical joints and drains to allow penetration. PVC waterproof shows excellent effects in completion of the dam, which however increases the possibility of interfacial failure due to different thermal expansion. Other causes of penetration may include problems with quality control during installation, generation of cracks due to heat of hydration of concrete, waterproofing methods, etc. In the case of Bohyunsan Dam in Yeongcheon, North Gyeongsang Province, the amount of drainage in the gallery was checked and underwater, and it was confirmed that there are many penetrations from drainage holes connected to vertical joints, and that some of the PVC waterproofs are not fully operated. As a new method to prevent penetration through vertical joints, D.S.I.M. (Dam Sealing Innovation Method) developed by World E&C was applied to Bohyunsan Dam and checked the amount of drainage in the gallery. As a result of first testing three most leaking vertical joints, the drain in the gallery was reduced by 87% on the average and then applied to the remaining 13 locations, which showed a 83% reduction effect based on the total drain in the gallery. Summing up these results, it was found that D.S.I.M. preventing water leakage from the upstream face is a valid construction method to reduce the water see-through and penetration quantity seen in downstream faces of concrete dams. If D.S.I.M. is applied to other concrete dams at domestic and abroad, it is expected that it will be very effective to prevent water leakage through vertical joints that are visible from downstream faces.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.2
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• pp.72-80
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• 2019

Purpose: The purpose of this study is to compare and analyze the shear bond strength and fracture pattern in different enamel tooth surface treatments for resin splinting materials. Materials and Methods: G-FIX and LightFix were used as tooth splinting materials. Twenty bovine mandibular incisors were used for the preparation of the specimens. The exposed enamel surface was separated into four parts. Each tooth was treated with 37% phosphoric acid, 37% phosphoric acid + adhesive resin, 37% phosphoric acid + G-premio bond, and G-premio bond for each fraction. Shear bond strength was measured using a universal testing machine. After measuring the shear bond strength, the fractured surface of the specimen was magnified with a microscope to observe the fracture pattern. Two-way ANOVA was used to verify the interaction between the material and the surface treatment method. One-way ANOVA was used for comparison between the surface treatment methods of each material and post-hoc test was conducted with Scheffe's test. An independent t-test was conducted to compare shear bond strengths between materials in each surface treatment method. All statistics were conducted at 95% significance level. Results: G-FIX, a tooth splinting resin, showed similar shear bonding strength when additional adhesive resins were used when material was applied after only acid etching, and LightFix showed the highest shear bonding strength when additional adhesive resins were used after the acid etching. In addition, both G-FIX and LightFix showed the lowest shear bond strength when only self-etching adhesive was applied without additional acid etching. Verification of interactions observed interconnection between resins and surface treatment methods. Most of the mixed failure was observed in all counties. Conclusion: When using G-FIX and LightFix, which are tooth-splinting materials, it is considered that sufficient adhesion will be achieved even after applying only acid etching as instructed by the manufacturer.

• The Korean Journal of Gastroenterology
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• v.72 no.6
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• pp.286-294
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• 2018

Background/Aims: The predictive factors of functional dyspepsia (FD) remain controversial. Therefore, we sought to investigate symptom responses in FD patients after Helicobacter pylori (H. pylori) eradication and used predictive factor analysis to identify significant factors of FD resolution at one-year after commencing eradication therapy. Methods: This prospective, multi-center clinical trial was performed on 65 FD patients that met Rome III criteria and had H. pylori infection. Symptom responses and factors that predicted poor response were determined by analysis one year after commencing H. pylori eradication therapy. Results: A total of 63 patients completed the one-year follow-up. When an eradication success group (n=60) and an eradication failure group (n=3) were compared with respect to FD response rate at one year, results were as follows; complete response 73.3% and 0.0%, satisfactory response 1.7% and 0.0%, partial response 10.0% and 33.3%, and refractory response 15.0% and 66.7%, respectively (p=0.013). Univariate analysis showed persistent H. pylori infection (p=0.021), female gender (p=0.025), and medication for FD during the study period (p=0.013) were associated with poor FD response at one year. However, age, smoking, alcohol consumption, and underlying disease were not found to affect response. Finally, multivariate analysis showed that female gender (OR, 4.70; 95% CI, 1.17-18.88) was the sole independent risk factor of poor FD response at one year after commencing H. pylori eradication therapy. Conclusions: Female gender was found to predict poor response in FD patients despite H. pylori eradication. Furthermore, successful H. pylori eradication appears to be associated with FD improvement, but the number of non-eradicated patients was too small to conclude.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.2
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• pp.183-202
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• 2019

For design and performance assessment of a high-level radioactive waste (HLW) disposal system, it is necessary to understand the characteristics of coupled thermo-hydro-mechanical (THM) behavior. However, in previous studies for the Korean Reference HLW Disposal System (KRS), thermal analysis was performed to determine the spacing of disposal tunnels and interval of disposition holes without consideration of the coupled THM behavior. Therefore, in this study, TOUGH2-MP/FLAC3D is used to conduct THM modeling for performance assessment of the Korean Reference HLW Disposal System (KRS). The peak temperature remains below the temperature limit of $100^{\circ}C$ for the whole period. A rapid rise of temperature caused by decay heat occurs in the early years, and then temperature begins to decrease as decay heat from the waste decreases. The peak temperature at the bentonite buffer is around $96.2^{\circ}C$ after about 3 years, and peak temperature at the rockmass is $68.2^{\circ}C$ after about 17 years. Saturation of the bentonite block near the canister decreases in the early stage, because water evaporation occurs owing to temperature increase. Then, saturation of the bentonite buffer and backfill increases because of water intake from the rockmass, and bentonite buffer and backfill are fully saturated after about 266 years. The stress is calculated to investigate the effect of thermal stress and swelling pressure on the mechanical behavior of the rockmass. The calculated stress is compared to a spalling criterion and the Mohr-Coulumb criterion for investigation of potential failure. The stress at the rockmass remains below the spalling strength and Mohr-Coulumb criterion for the whole period. The methodology of using the TOUGH2-MP/FLAC3D simulator can be applied to predict the long-term behavior of the KRS under various conditions; these methods will be useful for the design and performance assessment of alternative concepts such as multi-layer and multi-canister concepts for geological spent fuel repositories.