• The Korean Journal of Applied Statistics
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• v.17 no.2
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• pp.253-267
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• 2004

In some clinical trials, one may see that a significant fraction of patients are cured and their original disease does not recur even after termination of treatment and pro-longed follow-up. This situation occurs frequently in pediatric cancer trials where there are excellent therapeutic results. In such cases, interest concentrated on the difference of cure rates rather than other types of differences in failure distributions. Various authors have investigated the parametric and nonparametric methods for testing the difference of cure rates. In this study, we compare by simulation the power and size of a parametric test and five nonparametric tests in a various range of the alternatives, censoring rates and cure rates. Our objectives are to determine if any test was preferable on the basis of size and power in various situation, and to investigate the effect of the model misspecification.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1976.06a
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• pp.87.3-87
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• 1976

The authors experienced a case of a difficult decannulation in a 4 years old boy, in which. case decannulation was possible 2 years later a tracheostomy. Some immunoglogical phenomena could be considered in this case as though cancer can remiss spontaneously. Such complications of tracheostomy as subglottic edema and perichondritis could become relatively less troublesome to breathing during his aging process. And another reason for the easy decannulation is considered as the patient could be accustomed to breathing through natural air pathway by continual cannula corking training.

• Clinical and Experimental Pediatrics
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• v.46 no.7
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• pp.679-686
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• 2003

Purpose : Ataxia telangiectasia mutated(ATM) is involved in DNA damage responses at different cell cycle checkpoints, and signalling pathways associated with regulation of apoptosis in response to ionizing radiation(IR). However, the signaling pathway that underlies IR-induced apoptosis in ATM cells has remained unknown. The purpose of this study was, therefore, to investigate the apoptotic pathway that underlies IR-induced apoptosis in a CT-26 cells expressing dominant negative ATM (DN-ATM). Methods : We generated a replication-deficient recombinant adenovirus encoding the DN-ATM(Ad/DN-ATM) or control adenovirus encoding no transgene(Ad/GFP) and infected adenovirus to CT-26 cells. After infection, we examined apoptosis and apoptotic pathway by [$^3H$]-thymidine assay, DNA fragmentation, and Western immunoblot analysis. Results : DN-ATM gene served as the creation of AT phenotype in a CT-26 cells as revealed by decreased cell proliferations following IR. In addition, IR-induced apoptosis was regulated through the reduced levels of the anti-apoptotic protein Bcl-2, the increased levels of the apoptotic protein Bax, and the activation of caspase-9, caspase-3, and PARP. Conclusion : These results indicate that the pathway of IR-induced apoptosis in CT-26 cells expressing DN-ATM is mediated by mitochondrial signaling pathway involving the activation of caspase 9, caspase 3, and PARP.

• Journal of Chest Surgery
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• v.30 no.6
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• pp.591-597
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• 1997

Cardiopulmonary bypass in children is associated with capillary leak which results in an increase in total body water after open heart surgery The purpose of these studies was to assess the cardiopulmonary effects of modified ultrafiltration after pediatric open heart surgery Study h: Twenty-six consecutive children aged 0.1 ~ 10 years(median 7 months) underwent cardiac operation inc rporating modified ultrafiltration. After completion of cardiopulmonary bypass, modified ultrafiltration was commenced at the flow rate of 100~ 15011min for 3 ~ 14 min. After modified ultrafiltration, elevation of hematocrit(28.3% $\pm$ 3.6% vs. 33.8olo $\pm$ 4.Ooloi p < 0.001), increased systolic 1)loots Pressure(66.7 $\pm$ 11.2mmHg vs. 76.2$\pm$ 11.BmmHg, p < 0.02), and decreased central venous pressure(7.8 $\pm$ 3.7mmHg vs. 6.9$\pm$ 2.gmmHg, p<0.001) were observed. Study B: Twenty-six children who underwent cardiac operation with the diagnosis of VSD under 2 years were assigned to control(n= 14) or modified ultrafiltration(n= 12). Peak inspiratory pressure checked immediately after operation was significantly lower in modified ultrafiltration group than in control group(20.0$\pm$ 2.4 cmH20 vs.22.4$\pm$ 2.3cmH20, p < 0.03). Modified ultrafiltration after cardiopillmonary bypass in children improves early homodynamics and pulmonary mechanics, and represents an excellent option for perioperative managemen of accumulation of fluid in the tissues. We will continually employ the modified ultrafiltration technique in pediatric cardiac operations.

• Radiation Oncology Journal
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• v.20 no.2
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• pp.186-192
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• 2002

Purpose : Measurement of transmission dose is useful for in vivo dosimetry. In this study, previous algorithm for estimation of transmission dose was modified for use in cases with tissue deficit. Materials and Methods : The beam data was measured with flat solid phantom in various conditions of tissue deficit. New algorithm for correction of transmission dose for tissue deficit was developed by physical reasoning. The algorithm was tested in experimental settings with irregular contours mimicking breast cancer patients using multiple sheets of solid phantoms. Results : The correction algorithm for tissue deficit could accurately reflect the effect of tissue deficit with errors within ${\pm}1.0\%$ in most situations and within ${\pm}3.0\%$ in experimental settings with irregular contours mimicking breast cancer treatment set-up. Conclusion : Developed algorithm could accurately reflect the effect of tissue deficit and irregularly shaped body contour on transmission dosimetry.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.417-423
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• 2006

Purpose : The objectives of this study were to assess ventricular function by tissue Doppler imaging in children who were receiving chemotherapy or who had received chemotherapy, and to apply repeated tissue Doppler imaging to make an early assessment in cardiac toxicity studies. Methods : This study was conducted on 23 oncology patients on-treatment or off-treatment from April 2005 to July 2005 at Dongsan Medical Center, Keimyung University. All patients(group 1) were divided into two groups, fractional shortening(FS) over 29 percent(group 2) and FS under 28 percent (group 3) in the first category. These same patients were also divided into the following groups : group treated with anthracyclin(group 4) and group treated without anthracyclin(group 5). Deceleration time(DT), isovolumic relaxation time(IVRT), FS, peak early diastolic(E), and peak late diastolic (A) velocity of transmitral flow were measured by M-mode and pulsed wave Doppler. Systolic(Sm), peak early diastolic(Em), and peak late diastolic(Am) velocity in apical 4-chamber and 2-chamber views were measured by tissue Doppler imaging. The author calculated a modified Tei index, E/A, E/Em ratio by using measured values. Results : Twenty three patients were enrolled : 12 boys and 11 girls. The average age of patients was 8 years and 4 months. Thirteen out of 23 patients were in the group treated with anthracyclin (group 4) and 6 had FS under 28 percent(group 3). E/Em ratio showed a significant difference between group 1 and control group($6.46{\pm}1.85$ vs $7.06{\pm}1.64$, P<0.05). Other parameters had no difference statistically. Conclusion : This study showed that the change of cardiac function developed earlier in diastolic function than in systolic function, as E/Em ratio reflecting the mean LV diastolic pressure showed a significant difference between the control group and chemotherapy groups. Echocardiography using tissue Doppler imaging is a non-invasive, comfortable and reliable method for post-chemotherapy follow up.

• Korean Journal of Head & Neck Oncology
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• v.36 no.2
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• pp.9-15
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• 2020

Background/Objectives: To analyze the clinical characteristics of differentiated thyroid cancer (DTC) in children and adolescents. Materials & Methods: Medical records of 31 DTC cases that were diagnosed and treated at Korea Cancer Center Hospital between 2002 and 2018 were retrospectively reviewed. Results: Most cases were papillary carcinoma (n=26), with female predominance (n=25). Median age was 16.4 years (range, 11.9-18.6 years). Extrathyroidal extension was present in 24 cases. Twenty cases had tumor involvement at cervical lymph nodes and three had lung metastasis. Twenty-two patients received radioactive iodide treatment with a median cumulative dose of 300 mCi (range, 100-920 mCi). During a median follow-up of 68.2 months (range, 2.3-191.4 months), serum thyroglobulin level was elevated in 15 patients. Among them, two cases had remnant thyroid tissue, 4 had recurrence at cervical lymph nodes, and the remaining 9 did not have any detectable lesion. All were alive, and 5-year event-free survival (EFS) was 45.2±10.1%. Age £15 years, tumor size, lymph node status (N1b), and distant metastasis had negative effects on EFS. On multivariate analysis, age and tumor size had prognostic significance. Conclusion: For DTC of children and adolescents (£18 years old), age ≤15 years and tumor size were prognostic factor. Therefore, patients in this age group need meticulous follow-up. Further studies are necessary to answer the potential influence of age on the incidence and behavior of DTC.

• Journal of Yeungnam Medical Science
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• v.33 no.2
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• pp.105-111
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• 2016

Background: Neutropenic fever is one of the most common and potentially severe complications of chemotherapy in pediatric oncology patients, while urinary tract infection (UTI) is one of the most prevalent bacterial infections in these patients. Therefore, this study was conducted to investigate features of UTI with neutropenic fever in pediatric oncology patients. Methods: We retrospectively reviewed and analyzed the medical records, laboratory results and image findings of cases of neutropenic fever in the Department of Pediatrics of Yeungnam University Medical Center, South Korea between November 2013 and May 2015. Episodes were divided into two groups, UTI vs. non-UTI group according to the results of urine culture. The results were then compared between groups. The analysis was performed using IBM SPSS 23.0. A p-value <0.05 was considered to indicate a significant difference between groups. Results: Overall, 112 episodes of neutropenic fever were analyzed, among which 22 episodes (19.6%) showed organisms on urine culture and were classified as UTI. The remaining 90 episodes were classified as non-UTI. Only four episodes (18.2%) of the UTI group showed pyuria on urine analysis. In the UTI group, 76.5% were sensitive to the first line antibiotics and showed higher clinical response than the non-UTI group. Among hematologic malignancy patients, the UTI group revealed higher serum ${\beta}2$-microglobulin levels than the non-UTI group ($1.56{\pm}0.43mg/L$ vs. $1.2{\pm}0.43mg/L$, p<0.028). Conclusion: UTI in pediatric neutropenic fever responds well to antibiotics. Hematologic malignancy cases with UTI reveal increased serum ${\beta}2$-microglobulin level. These results will be helpful to early phase diagnosis of UTI.

• The Korean Journal of Pain
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• v.14 no.1
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• pp.51-55
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• 2001

Background: Oral mucositis is a common complication of anticancer chemotherapy. The sequelae of this consist of an increased risk of infection, moderate to severe pain, compromised oral function, and bleeding. This study was performed to evaluated the effects of the He-Ne laser and the Ga-Al-As laser on oral mucositis caused by anticancer chemotherapy in pediatric patients. Methods: There were 3 cases of osteosarcoma and 6 cases of leukemia. All patients received He-Ne laser (632.8 nm wavelength, power 60 mW) application on 400-600 Hz scanning for 5-20 minutes and Ga-Al-As laser (904 nm wavelength, power 40 mW) application by fiberoptic hand piece placed in immediate proximity to the tissue without direct contact with it for 30 seconds per point for 5 days per week. During the application patients wore wavelength-specific dark glasses and were instructed to keep their eyes closed. Results: The mean number of treatments with oral intake was $4.89{\pm}0.64$. The mean number of total treatments was $9.44{\pm}2.59$. There were no significant side effects during and after the laser treatments. Conclusions: He-Ne laser and Ga-Al-As (IR) laser treatment were well tolerated and reduced the severity and duration of chemotherapy-induced oral mucositis in pediatric oncologic patients.

• Investigative Magnetic Resonance Imaging
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• v.17 no.1
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• pp.41-46
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• 2013

We represent a pathologically proven case of a four-year-old male patient with renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion, which is rare but more frequent in children or young adults. Computed tomography showed about 2.5 cm size ill-defined mass in the right kidney. The mass was hyperechoic on ultrasound. Magnetic resonance imaging demonstrated a mass with capsular enhancement and diffusion restriction. We present a case of Xp11.2 renal cell carcinoma and provide review of the literature.