• Journal of the Korean earth science society
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• v.34 no.6
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• pp.524-535
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• 2013

Catastrophe risk models require the damage functions of each vulnerable item in inventory to estimate volcanic ash losses. The damage functions are used to represent the relation between damage factors and damage and also widely used in engineering and natural hazard studies to calculate the vulnerability. In most cases, damage functions are constructed as fragility or vulnerability curves, and researchers are confused by the similarities between them particularly when they perform interdisciplinary research. Thus, we aim to explain the similarities and differences between fragility and vulnerability curves and their relationship by providing case studies to construct them. In addition, we suggest a simple method to construct the damage functions between damage ratio and volcanic ash thickness using limited damage data. This study comes from the fact that damage functions are generally constructed using damage data. However, there is no available volcanic ash damage data in Korea, and not even enough volcanic disaster data to construct damage functions in the world, compared to other hazards. Using the method suggested in the study and the limited damage data from Japan and New Zealand, we construct Weibull-type functions or linear functions dependent of available data to calculate volcanic ash loss estimation, which we think need to be corrected to make it more suitable for inventory characteristics and environmental conditions in Korea.

• 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.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.185-190
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• 2014

Influence of loneliness on human survival has been established epidemiologically, but genomic research remains undeveloped. We identified 34 loneliness-associated genes which were statistically significant for high-lonely and low-lonely individuals. With the univariate Cox proportional hazards regression model, we obtained corresponding regression coefficients for loneliness-associated genes fo individual cancer patients. Furthermore, risk scores could be generated with the combination of gene expression level multiplied by corresponding regression coefficients of loneliness-associated genes. We verified that high-risk score cancer patients had shorter mean survival time than their low-risk score counterparts. Then we validated the loneliness-associated gene signature in three independent brain cancer cohorts with Kaplan-Meier survival curves (n=77, 85 and 191), significantly separable by log-rank test with hazard ratios (HR) >1 and p-values <0.0001 (HR=2.94, 3.82, and 1.78). Moreover, we validated the loneliness-associated gene signature in bone cancer (HR=5.10, p-value=4.69e-3), lung cancer (HR=2.86, p-value=4.71e-5), ovarian cancer (HR=1.97, p-value=3.11e-5), and leukemia (HR=2.06, p-value=1.79e-4) cohorts. The last lymphoma cohort proved to have an HR=3.50, p-value=1.15e-7. Loneliness-associated genes had good survival prediction for cancer patients, especially bone cancer patients. Our study provided the first indication that expression of loneliness-associated genes are related to survival time of cancer patients.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.5
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• pp.243-250
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• 2016

Objectives: Many studies have examined histopathological factors and various prognostic scores related to inflammation to predict outcomes. Here, we examined the prognostic value of the C-reactive protein/albumin (CRP/alb) ratio in oral squamous cell carcinoma (OSCC). Materials and Methods: This retrospective study included 40 patients with OSCC. Using univariate and multivariate analyses, we focused on the correlation of the CRP/alb ratio with clinicopathological characteristics and with overall survival. We then compared five inflammation-based prognostic scores, CRP/alb ratio, modified Glasgow Prognostic Score (mGPS), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and prognostic nutritional index (PNI), based on receiver operating characteristic (ROC) curves. Results: The optimal cut-off value for the CRP/alb ratio was 0.085. The group with a high CRP/alb ratio had a high TNM clinical stage (P=0.002) and larger primary tumors (P=0.029), with statistically significant differences in lymph node metastasis and distant metastasis. In addition, when the CRP/alb ratio was high, multivariate analysis showed a lower survival rate (P=0.002; hazard ratio=6.078), and the ROC curve showed more outstanding discriminatory ability regarding overall survival compared to other inflammation-based prognostic scores. Conclusion: The CRP/alb ratio can be an independent prognostic factor when predicting prognosis in OSCC and has good prognostic ability.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2195-2199
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• 2014

Background: Despite being rare in incidence, malignant tumors of major salivary glands show diverse histological variation. There are limited data on major salivary gland tumor management and outcome from Pakistan. The objective of this study was to share our experience with management of malignant tumors of major salivary glands. Materials and Methods: Patients who received treatment at Shaukat Khanum Cancer Hospital and Research Center from July 2002 to June 2011 with an underlying diagnosis of a major salivary gland malignancy were included. Patient characteristics and treatment modalities were assessed. Local, regional and distant failures were determined. Disease free survival (DFS) and overall survival (OS) were calculated using Kaplan Meier curves and the Log rank test was used to determine statistical significance. Univariate and multivariate analyses were performed using Cox proportional hazard regression. Results: The parotid gland was the primary site of origin in 104 (80%) patients. Mucoepidermoid carcinoma (43%) and adenoid cystic carcinoma (24%) were the most common histological types. Surgery followed by adjuvant radiation remained the mainstay treatment modality with 81 (62%) patients. Nineteen (15%) patients were treated with surgery alone and 30 (23%) patients with locally advanced surgically inoperable tumors received radiation only. Forty one (32%) patients failed the treatment (local 12, regional 11, locoregional 5, distant 13). The expected 5 year DFS and OS were 65% and 74% respectively. On multivariate analysis, grade was the only independent predictor of DFS and nodal involvement was the only independent predictor of overall survival. Conclusions: Employing existing standards of treatment, comparable survival can be achieved in Pakistani population with major salivary gland malignancies as elsehwere in the world.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.24
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• pp.10917-10922
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• 2015

Background: This study was conducted to determine DEPDC1 expression in hepatocelluar carcinomas (HCCs) and to reveal its potential role in diagnosis and prognosis of affected patients. Materials and Methods: DEPDC1 expression at the mRNA level was detected by quantitative real-time PCR (qRT-PCR) in 205 cases of HCC and paired adjacent normal liver tissues, and by semi-quantitative RT-PCR in 20 cases. Survival curves were obtained by using Kaplan-Meier method and Log-rank test. Independent predictors associated with regard to disease free survival (DFS) and overall survival (OS) were identified using the Cox proportional hazard model. Results: High DEPDC1 mRNA levels were detected in 144 out of 205 cases (70.24%) of HCC, significantly associated with clinicopathological parameters, including tumor size (${\geq}4cm$), alpha-fetoprotein (${\geq}100ng/ml$), B-C of BCLC stage and recurrence. Kaplan-Meier survival analysis revealed that HCC patients with high DEPDC1 expression had poor OS and DFS. Multivariate analysis demonstrated that high DEPDC1 expression was an independent predictor for OS (HR=1.651; 95% 95%CI, 1.041-2.617; p=0.033) and DFS (HR=1.583; 95%CI, 1.01-2.483; p=0.045). Conclusions: Our results indicate DEPDC1 might be a novel diagnostic marker and an independent prognostic predictor for HCC patients.

• Journal of Gastric Cancer
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• v.19 no.4
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• pp.393-407
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• 2019

Purpose: To identify the potential therapeutic role of postoperative radiotherapy (RT) in patients with locally advanced (stage II and stage III) gastric signet ring cell carcinoma (SRC). Materials and methods: Patients with locally advanced gastric SRC from the Surveillance, Epidemiology, and End Results program database between 2004 and 2012 were included in our study. Univariate and multivariate Cox proportional models were performed, and survival curves were generated to evaluate the prognostic effect of postoperative RT and surgery alone on SRC patients. Propensity score matching (PSM) was used to avoid selection bias among the study cohorts. Results: We found that patients with postoperative RT had better probability of survival compared with those who did not receive RT (overall survival [OS], P<0.001; cancer-specific survival [CSS], P<0.001). After PSM, analysis of both overall and CSS showed that patients who underwent postoperative RT had better prognosis than those receiving surgery alone in the matched cohort (OS, P=0.00079; CSS, P=0.0036). Multivariate Cox proportional model indicated that postoperative RT had better effect on prognosis compared with surgery alone with respect to both overall (hazard ratio [HR], 0.716; 95% confidence interval [95% CI], 0.590-0.87; P=0.001) and CSS (HR, 0.713; 95% CI, 0.570-0.890; P=0.003). Conclusions: Postoperative RT had better prognosis compared with surgery alone for both overall and CSS for patients with locally advanced gastric SRC.

• Journal of Preventive Medicine and Public Health
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• v.44 no.2
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• pp.84-92
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• 2011

Objectives: This study aimed to investigate smoking relapse and the related factors within 1 year after discharge from the smoking cessation clinics (SCCs) of public health centers (PHCs). Methods: Data were collected with a structured questionnaire from 395 people who success fully stopped smoking at 4 SCCs in Busan between May and June 2009, and this data were analyzed by Kaplan-Meier survival curves and the Cox proportional hazard model. Results: The rate of smoking relapse within 1 year after discharge from SCCs was 39.2% and this decreased rapidly over 6 months after discharge. The factors related to smoking relapse within 1 year after discharge from SCCs were being female (HR, 2.11; 95% CI, 1.17 to 3.82), a trial of smoking cessation with any assistants (HR, 1.95; 95% CI, 1.19 to 3.19), more than 7 ppm of exhaled CO2 on the SCCs' registration (HR, 1.81; 95% CI, 1.24 to 2.64), use of pharmacotherapy after discharge from SCCs (HR, 2.00; 95% CI, 1.36 to 2.93), alcohol drinking more than once a week after discharge from SCCs (HR, 3.32; 95% CI, 2.15 to 6.78), and a perceived barrier (HR, 1.21; 95% CI, 1.14 to 1.30) after discharge from the SCCs. Conclusions: According to the results, at least 6 months follow-up after discharge from SCCs of public health centers is recommended to reduce the rate smoking relapse. It is also recommended to strengthen the education on how to overcome barriers such as drinking in the course of smoking cessation clinics.

• Toxicological Research
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• v.35 no.4
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• pp.295-301
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• 2019

In this review, we describe the absorption rates (Caco-2 cell permeability) and hepatic/plasma pharmacokinetics of 53 diverse chemicals estimated by modeling virtual oral administration in rats. To ensure that a broad range of chemical structures is present among the selected substances, the properties described by 196 chemical descriptors in a chemoinformatics tool were calculated for 50,000 randomly selected molecules in the original chemical space. To allow visualization, the resulting chemical space was projected onto a two-dimensional plane using generative topographic mapping. The calculated absorbance rates of the chemicals based on cell permeability studies were found to be inversely correlated to the no-observed-effect levels for hepatoxicity after oral administration, as obtained from the Hazard Evaluation Support System Integrated Platform in Japan (r = -0.88, p < 0.01, n = 27). The maximum plasma concentrations and the areas under the concentration-time curves (AUC) of a varied selection of chemicals were estimated using two different methods: simple one-compartment models (i.e., high-throughput toxicokinetic models) and simplified physiologically based pharmacokinetic (PBPK) modeling consisting of chemical receptor (gut), metabolizing (liver), and central (main) compartments. The results obtained from the two methods were consistent. Although the maximum concentrations and AUC values of the 53 chemicals roughly correlated in the liver and plasma, inconsistencies were apparent between empirically measured concentrations and the PBPK-modeled levels. The lowest-observed-effect levels and the virtual hepatic AUC values obtained using PBPK models were inversely correlated (r = -0.78, p < 0.05, n = 7). The present simplified PBPK models could estimate the relationships between hepatic/plasma concentrations and oral doses of general chemicals using both forward and reverse dosimetry. These methods are therefore valuable for estimating hepatotoxicity.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.16-16
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• 2018

최근 국가시설물에서는 집중호우 등으로 인한 대상 부지 내의 홍수 발생 시 주요시설물에 기능 마비가 발생할 수 있고, 궁극적으로는 대규모 사고로 이어질 수 있기 때문에 외부침수에 대비할 수 있는 위험도 분석이 필요하다. 대상 부지에서의 외부침수의 원인으로서는 LIP(Local Intensive Precipitation)에 의한 홍수 발생조건, 인근에 댐, 제방 등이 위치한 경우 이들 시설물의 붕괴에 따른 홍수류의 원전 유입, 지진해일/폭풍해일에 의한 바다로부터의 홍수 유입 등이 대표적인 예이다. 따라서 대상 부지 및 그 SOC시설물의 안전도를 높은 수준에서 관리하기 위해서는 극한홍수가 유입될 때 침수심, 침수유속, 침수시간, 침수강도 등의 재해도를 분석하여야하고, 이들 SOC시설물의 취약도 평가를 실시하고 재해도와 취약도를 결합한 연계분석을 통하여 위험도를 재평가하여야 한다. 본 연구에서는 기후변화 시나리오에 대해서 LIP(극한강우) 조건을 빈도별 분석하였고, 기후변화에 의한 가능최대강우량(PMP)의 재포락을 실시하고, 이를 확률강우조건과 비교 검토하였다. 대상부지에서의 RCP4.5와 RCP8.5 조건하에서 발생빈도-지속시간-극한강우량과의 상관도를 제시하였다. 지형분석의 고도화 및 수문분석을 통한 LIP를 이용한 극한 홍수량의 산정을 실시하였고, 수리분석에 의한 극한홍수조건의 침수해석을 실시하였다. 침수해석을 통한 수리변량(침수심, 침수강도, 침수지속시간 등)을 산정하였고, 침수해석결과에 주요지점별 발생빈도-지속시간-침수위의 관계를 재해도로 제시하였다. 본 연구 결과 집중호우 조건하에서 국가 주요시설물에서의 침수심, 침수강도 등에 대한 새로운 재해도 곡선을 산정함으로써 중요한 SOC시설물의 내수 설계, 홍수 방지기능 설계, 홍수 방지 대책 및 절차의 고도화 및 홍수 저감 기능 평가에 기준이 될 것으로 판단된다.