• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.320-325
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• 2007

Promoter hypermethylation of the $p16^{INK4a}$ gene was investigated in 52 sets of samples of tumor tissue and adjacent normal tissue from Korean patients with colorectal cancer, using the proposed modified the Real-time PCR/SYBR Green detection method presented in this study. In normal tissue, 29 of 52 patients (56%) were methylated and in tumor tissue, 23 of 52 patients (44%) were methylated. The 34 cases (65.4%) showed a concordant DNA methylation pattern in both normal tissue and tumor tissue. Analyzing the association between the clinicopathologic features and DNA methylation status of the $p16^{INK4a}$ gene, the DNA methylation status according to by Duke's stage was different while other clinicopathological characteristics, including the age, sex, tumor stage, and histologic type of the patient were not found to be correlated with $p16^{INK4a}$ methylation. With multivariate logistic regression, it was observed that the DNA methylation status of $p16^{INK4a}$ gene in normal tissue was correlated with the DNA methylation status of the $p16^{INK4a}$ gene in tumor tissue (P=0.026). According to a Kaplan-Meier survival analysis, a difference in the survival rate by DNA methylation status was found, but it was not significant.

• Journal of Gastric Cancer
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• v.13 no.4
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• pp.247-254
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• 2013

Purpose: In Korea, the entire population must enroll in the national health insurance system, and those who are classified as having a lower socioeconomic status are supported by the medical aid system. The aim of this study was to evaluate the association of the medical insurance status of gastric cancer patients with their survival after gastrectomy. Materials and Methods: A total of 247 patients who underwent surgical treatment for gastric cancer between January 1999 and December 2010 at the Seoul Medical Center were evaluated. Based on their medical insurance status, the patients were classified into two groups: the national health insurance registered group (n=183), and the medical aid covered group (n=64). The survival rates were calculated using the Kaplan-Meier method. Results: The median postoperative duration of hospitalization was longer in the medical aid covered group and postoperative morbidity and mortality were higher in the medical aid group than in the national health insurance registered group (P<0.05). The overall 5-year survival rate was 43.9% in the medical aid covered group and 64.3% in the national health insurance registered group (P=0.001). Conclusions: The medical insurance status reflects the socioeconomic status of a patient and can influence the overall survival of gastric cancer patients. A more sophisticated analysis of the difference in the survival time between gastric cancer patients based on their socioeconomic status is necessary.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.178-183
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• 2001

Since the introduction of the concept of osseointegration, the success rate of dental implant has increased dramatically. So, the uses of dental implant in the treatment of partially or fully edentulous patients have played an important role in dental rehabilitation. Regardless of high success rate of dental implant, some amounts of fixtures cannot help failing. We can classify dental implant failure according to timing, causative factor, etc. This study is focused on dental implant fixture failure, occurring during preprosthetic stage. There are various reasons that cause implant failure on this periods, such as improper patient selection, poor bone quality, and periimplantitis, etc. We investigate the survival rate of 1058 fixtures, which installed in 306 patients in our clinic from January 1997 to December 1999, according to type, sex, location, fixture length and width, using Kaplan-Meier product-limit method and to compare each other with log-rank test. Overall survival rate was 96.80%, and 33 implants failed over the preprosthetic stage. Our survey data identified posterior location of mandible as being associated with implant failure(P<0.05).

• The Journal of Advanced Prosthodontics
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• v.8 no.3
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• pp.194-200
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• 2016

PURPOSE. The prospective follow-up aimed to assess the performance of lithium disilicate crowns and clinical reasons of adverse events compromising survival and quality. MATERIALS AND METHODS. 58 patients were treated with 375 heat-pressed monolithic crowns, which were bonded with resin cement. Annual recalls up to five years included a complete dental examination as well as quality assessment using CDA-criteria. Any need for clinical intervention led to higher complication rate and any failure compromised the survival rate. Kaplan-Meier-method was applied to all crowns and a dataset containing one randomly selected crown from each patient. RESULTS. Due to drop-outs, 45 patients (31 females, 14 males) with the average age of 43 years (range = 17-73) who had 327 crowns (176 anterior, 151 posterior; 203 upper jaw, 124 lower jaw) were observed and evaluated for between 4 and 51 months (median = 28). Observation revealed 4 chippings, 3 losses of retention, 3 fractures, 3 secondary caries, 1 endodontic problem, and 1 tooth fracture. Four crowns had to be removed. Survival and complication rate was estimated 98.2% and 5.4% at 24 months, and 96.8% and 7.1% at 48 months. The complication rate was significantly higher for root canal treated teeth (12%, P<.01) at 24 months. At the last observation, over 90% of all crowns showed excellent ratings (CDA-rating Alfa) for color, marginal fit, and caries. CONCLUSION. Heat pressed lithium disilicate crowns showed an excellent performance. Besides a careful luting, dentists should be aware of patients' biological prerequisites (grade of caries, oral hygiene) to reach full success with these crowns.

• Korean Journal of Head & Neck Oncology
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• v.31 no.2
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• pp.29-35
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• 2015

목적 : 국소 재발한 진행된 갑상선 유두암의 치료로 수술 후 외부방사선의 역할을 알아보고자 하였다. 대상 및 방법 : 원자력병원에서 2000년 1월부터 2012년 2월까지 사이버나이프 혹은 외부방사선 치료를 받은 수술과 방사선요오드 치료 후 국소 재발한 진행된 갑상선 유두암 환자 13 명을 대상으로 하였다. 경과관찰 기간 동안 국소 및 부위 재발이 발생환 환자는 6 명이었다. 몇몇의 위험인자를 찾기 위해서 Kaplan-Meier method와 log-rank test를 이용하여 성별, 종양단계, 방사선 치료 전 수술 횟수, 방사선요오드치료 횟수, 수술 후 잔존 암의 여부, 원격전이에 대해 단변량 분석하였다. 결과 : 방사선 치료 후 평균 추적관찰기관은 53.8개월(범위, 36 ~ 108개월)이고 그중 남자는 4 명이었다. 1년, 2년의 무진행 생존률은 각각 76.9와 53.8%였다. 단병량 분석은 성별과 잔존 암여부(p = 0.0475 and p = 0.0475, 각각)에 따라 무진행 생존률이 진행한 그룹과 진행하지 않은 그룹 사이에 유의한 차이가 있다는 것을 보여줬다. 결론 : 외부 방사선 치료 전에 잔존 암이 없었던 환자의 100%에서 국소 및 부위 재발이 일어나지 않았다. 외부방사선 치료는 수술과 방사선요오드 치료에 반응하지 않는 환자 중 수술 후 잔존 암이 없는 경우에 효과적인 치료 방법이 될 수 있다.

• Journal of Chest Surgery
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• v.26 no.4
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• pp.249-254
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• 1993

Atrial fibrillation is commonly associated with organic mitral valve disease including rheumatic valvular heart diasease or mitral valve prolapse and so forth. Although spontaneous sinus reversion may occur in some patients after mitral valve operation, recurrence of atrial fibrillation is the rule in most of these patients. We have tried to maintain sinus rhythm after mital valve operation with oral quinidine therapy, and we will show the efficacy of this therapy in this report. From January 1986 to August 1992, 60 patients of mitral valvular heart disease, who had had atrial fibrillation preoperatively and gained sinus rhythm postoperatively, were selected for this study. These patients were divided into 2 groups: Control group [n=30] and Quinidine trial group [n=30]. The age,sex, duration of symptoms,left atrial size and other risk factors of the reversion to atrial fibrillation were adjusted to be similar between the two groups. The maintenance rate of sinus rhythm was calculated by Kaplan-Meier method, and the rate was significantly higher in quinidine trial group than in control group [ p=0.0001 ]. Univariate analysis was performed on the risk factors of reversion to atrial fibrillation, and the difference of maintenance rate between the two groups were corrected with this result: the difference was still statistically significant [ p=0.0205 ]. The quinidine levels were measured in postoperative days, and there were no difference of serum quinidine level between the quinidine success group and quinidine failure group. In conslusion, oral quinidine therapy was effective for the maintenance of sinus rhythm after mitral valve operation compared to control group, and there was no correlation between the serum quinidine level and clinical efficacy of quinidine therpy.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.54-59
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• 1996

Liposarcoma is second in frequency only to malignant fibous histocytoma among the soft tissue sarcoma. Many different factors which might affect the survival rate of liposarcoma have been reported by many authors. The purpose of this study was to evaluate survival rate of liposarcoma and define the prognostic factors that affected survival rate. The authors analysed retrospectively 17 patients of liposarcoma in extremities from May 1984 to Dec. 1995 who had been treated in department of orthopaedic surgery of Kosin University Medical Center. All cases were resected with marginal or wide margin. There were 9 men and 8 women. The mean age was 48 years. The follow-up period ranged from 15 to 96 months. We compared the prognosis of the patients with several factors; age, sex, surgical staging, size, site, histologic type and treatment modality. At last follow-up, the presence of local recurrence was in 3 cases and the presence of lung metastasis was in 8 cases. The survival rates by Kaplan-Meier product limit method at 2 years and 5 years were 87% and 57% respectively. The statististically significant difference was estimated in histologic type, but was not estimated in age, sex surgical staging, size, site and treatment modality. In conclusion, the histologic type is considered as the most important factor of the prognosis in liposarcoma. Although it was too few patients for the differences to be statistically significant, we consider that surgical staging, site, size, the radio-therapy and chemothrapy in liposarcoma will affect the prognosis.

• Journal of Korean Neurosurgical Society
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• v.55 no.2
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• pp.69-72
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• 2014

Objective : There was no abundance of data on the use of anticoagulant in patients with previous high risk of thromboembolic conditions under a newly developed intracranial hemorrhage in Korean society. The purpose of this study was to evaluate the safety of discontinuance and suggest the proper time period for discontinuance of anticoagulant among these patients. Methods : We reviewed the medical records of 19 patients who took anticoagulant because of thromboembolic problems and were admitted to our department with newly developed anticoagulation associated intracranial hemorrhage (AAICH), and stopped taking medicine due to concern of rebleeding from January 2008 to December 2012. Analysis of the incidence of thromboembolic complications and proper withdrawal time of anticoagulant was performed using the Kaplan-Meier method. Results : Our patients showed high risk for thromboembolic complication. The $CHA_2DS_2$-VASc score ranged from two to five. Thromboembolic complication occurred in eight (42.1%) out of 19 patients without restarting anticoagulant since the initial hemorrhage. Among them, three patients (37.5%) died from direct thromboembolic complications. Mean time to outbreak of thromboembolic complication was $21.38{\pm}14.89$ days (range, 8-56 days). The probability of thromboembolic complications at 7, 14, and 30 days since cessation of anticoagulation was 0.00, 10.53, and 38.49%, respectively. Conclusion : Short term discontinuance of anticoagulant within seven days in patients with AAICH who are at high embolic risk ($CHA_2DS_2$-VASc score >2) appears to be relatively safe in Korean people. However, prolonged cessation (more than seven days) may result in increased incidence of catastrophic thromboembolic complications.

• Archives of Plastic Surgery
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• v.36 no.3
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• pp.299-305
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• 2009

Purpose: Recently, the incidence of malignant melanoma has been steadily increasing. Malignant melanoma is already known to have poorer prognosis than other primary skin cancers. Despite the poor prognosis, it is relatively less known to the public so that a number of patients visit hospital carrying advanced stage tumor. Yet, extensive study about malignant melanoma is currently insufficient, and specific guidelines and statistical figures in Korea are almost inexistent. Therefore, authors reviewed patients with malignant melanoma who have visited our hospital for last 14 years. Methods: Between January 1994 and January 2008, 62 patients were diagnosed with malignant melanoma at our hospital. A retrospective study was performed with data from patients' charts and biopsy results. Annual incidence, mean age of onset, gender, tumor location, tumor thickness, pathologic ulceration, clinicopathologic subtype, and clinical AJCC stage were evaluated. Analysis of factors associated with survival were performed using the Cox proportional hazard model. Kaplan - Meier method was used to generate survival curves. Results: Clinicopathologic features of 62 patients (32 male, 30 female) with average age of 57 years were evaluated. Most lesions were found in lower limb, and the most common subtype was acral lentiginous melanoma. We could also find that age, tumor thickness, and clinical stage were the only significant prognostic factors. Conclusion: Clinicopathologic features of malignant melanoma were analyzed in this study, but the result is not ready to be generalized because the number of cases is too small. Further study must be performed to report clinical guidelines for prognosis and treatment for malignant melanoma patients in Korea.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.1
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• pp.41-46
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• 2014

Purpose: The spontaneous seroconversion rate of hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) virus infection in children is lower than that in adults. However, few studies have investigated the rate of transition from the immune-tolerant to the early immune-clearance phase in children. Methods: From February 2000 to August 2011, we enrolled 133 children aged <18 years who had visited the Department of Pediatrics, Kyungpook National University Hospital. All subjects were in the immune-tolerant phase of HBeAg-positive CHB virus infection. The estimated transition rate into the early immune-clearance phase was calculated using the Kaplan-Meier method. Results: Among the 133 enrolled pediatric CHB virus infection patients in the HBeAg-positive immune-tolerant phase, only 21 children (15.8%) had converted to the early immune-clearance phase. The average age at entry into active hepatitis was $10.6{\pm}4.8$ years. The incidence of transition from the immune-tolerant to the early immune-clearance phase in these children was 1.7 episodes/100 patient-years. When analyzed by age, the estimated transition rate was 4.6%, 7.1%, and 28.0% for patients aged <6, 6-12, >12 years, respectively. Conclusion: In children with CHB virus infection, the estimated rate of entry into the early immune-clearance phase was 28.0% for patients aged 12-18 years, which was significantly higher than that observed for children aged <12 years (11.7%; p=0.001).