• Tuberculosis and Respiratory Diseases
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• 제71권1호
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• pp.8-14
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• 2011

Background: MicroRNAs (miRNAs) have demonstrated their potential as biomarkers for lung cancer diagnosis. In recent years, miRNAs have been found in body fluids such as serum, plasma, urine and saliva. Circulating miRNAs are highly stable and resistant to RNase activity along with, extreme pH and temperatures in serum and plasma. In this study, we investigated serum miRNA profiles that can be used as a diagnostic biomarker of non-small cell lung cancer (NSCLC). Methods: We compared the expression profile of miRNAs in the plasma of patients diagnosed with lung cancer using an miRNA microarray. The data from this assay were validated by quantitative real-time PCR (qRT-PCR). Results: Six miRNAs were overexpressed and three miRNAs were underexpressed in both tissue and serum from squamous cell carcinoma (SCC) patients. Sixteen miRNAs were overexpressed and twenty two miRNAs were underexpressed in both tissue and serum from adenocarcinoma (AC) patients. Of the four miRNAs chosen for qRT-PCR analysis, the expression of miR-23a was consistent with microarray results from AC patients. Receiver operating characteristic (ROC) curve analyses were done and revealed that the level of serum miR-23a was a potential marker for discriminating AC patients from chronic obstructive pulmonary disease (COPD) patients. Conclusion: Although a small number of patients were examined, the results from our study suggest that serum miR-23a can be used in the diagnosis of AC.

• 전자공학회논문지SC
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• 제48권4호
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• pp.1-9
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• 2011

쇼크(shock)란 조직에 필요한 산소 요구량과 공급 간의 불균형에 의해 유발되는 임상증후군을 말한다. 환자의 치료효과와 생존율 향상을 위해서 쇼크의 조기 진단은 매우 중요하다. 그러나 현재 쇼크 진단에 사용되는 맥박, 혈압 등 생체 징후의 경우 출혈 정도를 제대로 반영하지 못하여 환자에 대한 처치가 늦어질 수 있다. 따라서 쇼크의 조기 진단을 위한 많은 연구들이 진행되어 왔으며, 조직의 저산소증, 대사성 산증을 반영해주는 지표인 젖산 농도와 관류 측정의 유용성이 입증된 바 있다. 본 연구에서는 흰쥐를 대상으로 정량적 출혈을 유도한 후, 젖산 농도 측정과 laser Doppler flowmeter를 통해 관류를 측정하였으며, 지혈 후 젖산 농도/관류의 비(ratio)를 생존 예측을 위한 새로운 지표로써 제안하였다. 새로 제안된 지표를 통한 생존예측을 ROC 커브 방법에 적용한 결과, 민감도 90.0%, 특이도 96.7%, 정확도 94.0%를 보였으며, 생존군과 사망군 간 새로운 지표의 유의한 차이도 가장 조기에 보여주었다. 향후 임상 적용 연구를 통해 새롭게 제안한 지표의 임상 적용이 가능하다면, 쇼크 환자를 조기 진단하고 치료효과를 높일 수 있을 것으로 생각된다.

• Journal of Dental Anesthesia and Pain Medicine
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• 제20권5호
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• pp.293-301
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• 2020

Background: The success rate of intubation under direct laryngoscopy is greatly influenced by laryngoscopic grade using the Cormack-Lehane classification. However, it is not known whether grade under direct laryngoscopy can also affects the success rate of nasotracheal intubation using a fiberoptic bronchoscpe, so this study investigated the same. In addition, we investigated other factors that influence the success rate of fiberoptic nasotracheal intubation (FNI). Methods: FNI was performed by 18 anesthesiology residents under general anesthesia in patients over 15 years of age who underwent elective oral and maxillofacial operations. In all patients, the Mallampati grade was measured. Laryngeal view grade under direct laryngoscopy, and the degree of secretion and bleeding in the oral cavity was measured and divided into 3 grades. The time required for successful FNI was measured. If the intubation time was > 5 minutes, it was evaluated as a failure and the airway was managed by another method. The failure rate was evaluated using appropriate statistical method. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were also measured. Results: A total of 650 patients were included in the study, and the failure rate of FNI was 4.5%. The patient's sex, age, height, weight, Mallampati, and laryngoscopic view grade did not affect the success rate of FNI (P > 0.05). BMI, the number of FNI performed by residents (P = 0.03), secretion (P < 0.001), and bleeding (P < 0.001) grades influenced the success rate. The AUCs of bleeding and secretion were 0.864 and 0.798, respectively, but the AUC of BMI, the number of FNI performed by residents, Mallampati, and laryngoscopic view grade were 0.527, 0.616, 0.614, and 0.544, respectively. Conclusion: Unlike in intubation under direct laryngoscopy, in the case of FNI, oral secretion and nasal bleeding had a significant effect on FNI difficulty than Mallampati grade or Laryngeal view grade.

• Journal of Gastric Cancer
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• 제21권3호
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• pp.268-278
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• 2021

Purpose: While several prognostic models for the stratification of death risk have been developed for patients with advanced gastric cancer receiving first-line chemotherapy, they have seldom been tested in the Chinese population. This study investigated the performance of these models and identified the optimal tools for Chinese patients. Materials and Methods: Patients diagnosed with metastatic or recurrent gastric adenocarcinoma who received first-line chemotherapy were eligible for inclusion in the validation cohort. Their clinical data and survival outcomes were retrieved and documented. Time-dependent receiver operating characteristic (ROC) and calibration curves were used to evaluate the predictive ability of the models. Kaplan-Meier curves were plotted for patients in different risk groups divided by 7 published stratification tools. Log-rank tests with pairwise comparisons were used to compare survival differences. Results: The analysis included a total of 346 patients with metastatic or recurrent disease. The median overall survival time was 11.9 months. The patients were different into different risk groups according to the prognostic stratification models, which showed variability in distinguishing mortality risk in these patients. The model proposed by Kim et al. showed relative higher predicting abilities compared to the other models, with the highest χ² (25.8) value in log-rank tests across subgroups, and areas under the curve values at 6, 12, and 24 months of 0.65 (95% confidence interval [CI]: 0.59-0.72), 0.60 (0.54-0.65), and 0.63 (0.56-0.69), respectively. Conclusions: Among existing prognostic tools, the models constructed by Kim et al., which incorporated performance status score, neutrophil-to-lymphocyte ratio, alkaline phosphatase, albumin, and tumor differentiation, were more effective in stratifying Chinese patients with gastric cancer receiving first-line chemotherapy.

• 대한임상독성학회지
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• 제18권2호
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• pp.66-77
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• 2020

Purpose: The aims of the present study were twofold. First, the research investigated the effect of an individual's risk factors and the prevalence of psychotropic drugs on QTc prolongation, TdP (torsades de pointes), and death. Second, the study compared the risk scoring systems (the Mayo Pro-QT risk score and the Tisadale risk score) on QTc prolongation. Methods: The medical records of intoxicated patients who visited the emergency department between March 2010 and February 2019 were reviewed retrospectively. Among 733 patients, the present study included 426 psychotropic drug-intoxicated patients. The patients were categorized according to the QTc value. The known risk factors of QTc prolongation were examined, and the Mayo Pro-QT risk score and the Tisadale risk score were calculated. The analysis was performed using multiple logistic regression, Spearman correlation, and ROC (receiver operating characteristic). Results: The numbers in the mild to moderate group (male: 470≤QTc<500 ms, female: 480≤QTc<500 ms) and severe group (QTc≥500 ms or increase of QTc at least 60ms from baseline, both sex) were 68 and 95, respectively. TdP did not occur, and the only cause of death was aspiration pneumonia. The statically significant risk factors were multidrug intoxications of TCA (tricyclic antidepressant), atypical antipsychotics, an atypical antidepressant, panic disorder, and hypokalemia. The Tisadale risk score was larger than the Mayo Pro-QT risk score. Conclusion: Multiple psychotropic drugs intoxication (TCA, an atypical antidepressant, and atypical antipsychotics), panic disorder, and hypokalemia have been proven to be the main risk factors of QTc prolongation, which require enhanced attention. The present study showed that the Tisadale score had a stronger correlation and predictive accuracy for QTc prolongation than the Mayo Pro-QT score. As a result, the Tisadale risk score is a crucial assessment tool for psychotropic drug-intoxicated patients in a clinical setting.

• Investigative Magnetic Resonance Imaging
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• 제26권2호
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• pp.104-116
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• 2022

The purpose of this study is to systematically determine an optimal percentile cut-off in histogram analysis for calculating the mean parameters obtained from a non-Gaussian continuous-time random-walk (CTRW) diffusion model for differentiating individual glioma grades. This retrospective study included 90 patients with histopathologically proven gliomas (42 grade II, 19 grade III, and 29 grade IV). We performed diffusion-weighted imaging using 17 b-values (0-4000 s/mm²) at 3T, and analyzed the images with the CTRW model to produce an anomalous diffusion coefficient (D_m) along with temporal (𝛼) and spatial (𝛽) diffusion heterogeneity parameters. Given the tumor ROIs, we created a histogram of each parameter; computed the P-values (using a Student's t-test) for the statistical differences in the mean D_m, 𝛼, or 𝛽 for differentiating grade II vs. grade III gliomas and grade III vs. grade IV gliomas at different percentiles (1% to 100%); and selected the highest percentile with P < 0.05 as the optimal percentile. We used the mean parameter values calculated from the optimal percentile cut-offs to do a receiver operating characteristic (ROC) analysis based on individual parameters or their combinations. We compared the results with those obtained by averaging data over the entire region of interest (i.e., 100th percentile). We found the optimal percentiles for D_m, 𝛼, and 𝛽 to be 68%, 75%, and 100% for differentiating grade II vs. III and 58%, 19%, and 100% for differentiating grade III vs. IV gliomas, respectively. The optimal percentile cut-offs outperformed the entire-ROI-based analysis in sensitivity (0.761 vs. 0.690), specificity (0.578 vs. 0.526), accuracy (0.704 vs. 0.639), and AUC (0.671 vs. 0.599) for grade II vs. III differentiations and in sensitivity (0.789 vs. 0.578) and AUC (0.637 vs. 0.620) for grade III vs. IV differentiations, respectively. Percentile-based histogram analysis, coupled with the multi-parametric approach enabled by the CTRW diffusion model using high b-values, can improve glioma grading.

• 한국노년학
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• 제39권4호
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• pp.895-902
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• 2019

이 연구에서는 요인분석을 통해 타당성이 입증된 낙상위험평가 설문항목의 진단 정도와 평가기준을 검토하여 지역 재가 노인의 낙상고위험군을 진단하고 개인별 낙상리스크 프로파일을 제안하는데 목적이 있다. 연구대상자는 S시, U시, B시, Y시 거주 우리나라 지역 재가 노인 439명을 대상으로 하였다(평균연령 75.0±5.7세). FRA의 낙상위험진단정도와 평가기준을 검토하기 위해 ROC분석을 실시하였다. 분석결과 FRA의 하위요인인 '낙상잠재성', '질병과 신체증상', '환경' 및 '신체기능'의 4가지 하위 요인은 지역재가노인의 낙상 위험을 효율적으로 진단할 수 있는 것으로 나타났으며, 민감도와 특이도 결과를 바탕으로 요인별 평가기준을 제시하였다. 또한 낙상하위요인별 패턴을 분석한 결과 낙상 고위험군의 경우 두 가지 요인 이상에 문제를 가지고 있는 노인이 전체의 80%를 차지하는 것으로 나타났다. 이상으로, FRA의 4가지 하위 요인은 낙상위험정도를 효율적으로 진단할 수 있으며, 평가기준을 바탕으로 개인별 낙상위험프로파일을 제시할 수 있어 우리나라 지역 재가 노인의 낙상예방프로그램 구축을 위한 기초자료로 활용할 수 있을 것이다.

• 한국지형학회지
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• 제27권1호
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• pp.61-89
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• 2020

The objective of this study is to characterize landslide susceptibility depending on various geo-environmental variables as well as to compare the Frequency Ratio (FR) and Evidential Belief Function (EBF) methods for landslide susceptibility analysis of rainfall-induced landslides. In 2013, a total of 259 landslides occurred in Chuncheon, Gangwon Province, South Korea, due to heavy rainfall events with a total cumulative rainfall of 296~721mm in 106~231 hours duration. Landslides data were mapped with better accuracy using the geographic information system (ArcGIS 10.6 version) based on the historic landslide records in Chuncheon from the National Disaster Management System (NDMS), the 2013 landslide investigation report, orthographic images, and aerial photographs. Then the landslides were randomly split into a testing dataset (70%; 181 landslides) and validation dataset (30%; 78 landslides). First, geo-environmental variables were analyzed by using FR and EBF functions for the full data. The most significant factors related to landslides were altitude (100~200m), slope (15~25°), concave plan curvature, high SPI, young timber age, loose timber density, small timber diameter, artificial forests, coniferous forests, soil depth (50~100cm), very well-drained area, sandy loam soil and so on. Second, the landslide susceptibility index was calculated by using selected geo-environmental variables. The model fit and prediction performance were evaluated using the Receiver Operating Characteristic (ROC) curve and the Area Under Curve (AUC) methods. The AUC values of both model fit and prediction performance were 80.5% and 76.3% for FR and 76.6% and 74.9% for EBF respectively. However, the landslide susceptibility index, with classes of 'very high' and 'high', was detected by 73.1% of landslides in the EBF model rather than the FR model (66.7%). Therefore, the EBF can be a promising method for spatial prediction of landslide occurrence, while the FR is still a powerful method for the landslide susceptibility mapping.

• 한국시뮬레이션학회논문지
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• 제32권4호
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• pp.19-26
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• 2023

전국 대학생의 중도 탈락 비율의 증가는 학생 개인 뿐만 아니라 대학과 사회에 심각한 부정적 영향을 끼친다. 본 연구에서는 중도 탈락이 예상되는 학생을 사전에 식별하기 위하여, 각 대학의 학사관리 시스템에서 손쉽게 얻을 수 있는 학적 데이터를 기반으로 머신러닝 분야의 결정트리, 랜덤 포레스트, 로지스틱 회귀 및 딥러닝 기반의 중도 탈락 예측 모델을 구축하고, 그 성능을 비교·분석하였다. 분석 결과 로지스틱 회귀 기반 예측 모델의 재현율이 가장 높았으나 f-1 및 auc 값이 낮은 한계를 보였고, 랜덤 포레스트 기반의 예측 모델의 경우 재현율을 제외한 다른 모든 지표에서 가장 우수한 성능을 보였다. 또한 예측 기간에 따른 예측 모델의 성능을 확인하기 위하여 예측 기간을 단기(1개 학기 이내), 중기(2개 학기 이내) 및 장기(3개 학기 이내)로 나누어 분석해 본 결과, 장기 예측 시 가장 높은 예측력을 보였다. 본 연구를 통해 각 대학은 중도 탈락이 예상되는 학생들을 조기에 식별하고, 이들에 대한 집중 관리를 통해 중도 탈락 비율을 줄이며 나아가 대학 재정 안정화에 기여할 수 있을 것으로 기대된다.

• Investigative Magnetic Resonance Imaging
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• 제18권2호
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• pp.120-132
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• 2014

목적: 원발성 뇌종양환자에서 방사선 치료 후 추적 자기공명영상에서 새로 생긴 조영증강 뇌병변에 대해 종양재발과 지연성 방사선치료연관변화의 감별에 있어서 확산강조영상 (DWI), 역동적조영관류영상 (DSC PWI), 자화율강조영상 (SWI)의 진단적 가치를 서로 비교하고자 한다. 대상과 방법: 원발성 뇌종양으로 이전에 방사선치료를 받았던 환자 중, 방사선치료 종료 최소 1년 이후에 추적 자기공명영상에서 새롭게 조영증강 되는 병변을 가진 24명의 환자를 대상으로 연구하였다. 새롭게 조영증강 되는 병변은 14명의 종양재발과 10명의 방사선치료연관변화로 확인되었다. 종양재발과 방사선치료연관변화 두 환자 군의 여러변수들은 비대응표본 t 검정을 실시하여 비교 분석하였다. 다중변수 로지스틱 회귀 분석을 이용하여 DWI, DSC PWI, SWI 각 영상의 정량 분석을 통해 얻은 apparent diffusion coefficient (ADC), normalized cerebral blood volume (nCBV), proportion of dark signal intensity (proSWI) 값 중 두 군을 감별해 내는 최상의 예측 변수 (best predictor)를 정하였다. 이후 수신자 조작 특성 (Receiver operating characteristics, ROC) 분석을 통하여 best predictor의 정확도, 민감도, 특이도를 평가하였다. 결과: 방사선치료연관변화 군과 비교하여 종양재발 군에서 평균 nCBV 값이 유의하게 높았고 (P=.004), 평균 proSWI 값은 유의하게 낮았다 (P<.001). 반면, 평균 ADC 값은 두 군간에 유의한 차이를 보이지 않았다. 다중변수 로지스틱 회귀 분석 결과 proSWI 값만이 통계적으로 유의한, 감별 가능한 독립변수였으며, 민감도, 특이도, 정확도는 각각 78.6% (11 of 14), 100% (10 of 10), 87.5% (21 of 24) 였다. 결론: 뇌종양 환자에서 방사선치료 종료 최소 1년 이후에 새로 보이는 조영증강 병변의 감별에 있어 proSWI 값이 가장 중요한 변수인 것으로 나타났다.