• Journal of Pharmaceutical Investigation
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• 제33권4호
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• pp.267-272
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• 2003

Herpes simplex virus (HSV) thymidine kinase (TK) has been widely used for suicidal gene therapy in combination with nucleoside analogs such as ganciclovir (GCV). The use of HSV-TK is limited due to the side effect of GCV at high concentrations. Previous studies showed that stable transfectants of mutant HSV-TK with enhanced affinity to GCV were killed at lower GCV concentrations. In this study, we tested whether mutant HSV-TK can provide enhanced suicidal effect when transiently transfected with Epstein-Barr virus (EBV)-based plasmid. EBV-based plasmid which contains OriP and EBNA-1 sequence is well known for a stable episomal maintenance in human cells. Optimal transfection condition was assessed for SNU-638 gastric cancer cell line using polyetylnimine (PEI). Maximum transfection efficiency was achieved when DNA:PEI was 1:3 (w/v). Cytotoxicities of mutant and wild type HSV-TK were compared before and after partially selecting transfected cells. The cells were sensitive to $100\;{\mu}g/ml$ hygromycin. Following GCV treatment, more cells were killed after hygromycin selection than before selection. The mutant HSV-TK showed enhanced cytotoxicity compared with the wild type HSV-TK. Our results suggest that the EBV-based plasmid encoding mutant HSV-TK may be useful to treat the diseases caused by uncontrolled cell proliferation such as cancer and rheumatoid arthritis.

• 대한본초학회지
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• 제36권5호
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• pp.37-46
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• 2021

Objective : This study aims to examine the effectiveness and safety of herbal medicines in upper respiratory tract infection by conducting systematic review against amoxicillin. Methods : Relevant randomized controlled trials (RCTs) published by December 2020 were searched in PubMED database. Study selection was conducted according to the PRISMA guideline. The Risk of Bias of the RCTs were evaluated based on the Cochrane criteria. Study selection and bias assessment were conducted independently by two researchers, and the third party was involved if there is a disagreement. Results : Three RCTs were included. Meta-analysis was not performed due to different specific disease and outcome measurements among the included studies. Herbal medicine showed statistically significant improvement in symptoms and endoscopic findings compared to amoxicillin in acute rhinosinusitis. In addition, herbal medicine showed statistically significant improvement in symptoms and a smaller dose of additional antibiotics in acute tonsillitis. However, herbal medicine showed no significant effects compared to amoxicillin in chronic sinusitis patients after functional endoscopic sinus surgery. In terms of adverse events, no significant difference was observed between the herbal medicine group and the amoxicillin group in all studies. Conclusion : Herbal medicine might be more effective than amoxicillin in the treatment of upper respiratory tract infection. Nevertheless, it is hard to clear that conclusion due to the fact that the collected studies were conducted on different specific diseases and herbal medicine, and that the included studies had flaws in the research methodology.

• 융합정보논문지
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• 제8권5호
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• pp.131-135
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• 2018

현대인의 사망원인 2위를 차지하고 있는 심장병은 자각 증세 없이 갑자기 돌연사를 당할 수 있는 무서운 질병으로 예방이 중요하다. 심장병 중 대동맥판막 협착증을 판단하기 위해서 physioNet에서 제공하는 심음 데이터 중 S1과 S2 사이의 수축 심음 데이터를 이용하여 병명을 진단하였다. 대동맥 판막은 좌심실에서 대동맥으로 피가 유출되는 부위의 판막이다. 심장병 중 대동맥판막 협착증은 대동맥판막이 좁아져 좌심실의 수축 시 판막이 열리지 않는 질환이다. 위 논문에서는 정상인과 대동맥판막 협착증 환자를 합쳐 특징이 180개로 이루어진 3126개의 샘플 심음 데이터를 실험데이터로 사용하였다. 정상과 대동맥판막 협착증 환자를 구분하기 위해 가중퍼지신경망(NEWFM, Neural Network with Weighted Fuzzy Membership Function)이용하였다. 가중퍼지신경망의 특징선택 방법으로 가중치의 평균 방법을 이용하였으며, 분류 결과는 91.0871%의 정확도를 나타내었다.

• Journal of Preventive Medicine and Public Health
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• 제42권4호
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• pp.267-273
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• 2009

Objectives : To compare the performance of three comorbidity measurements (Charlson comorbidity index, Elixhauser s comorbidity and comorbidity selection) with the effect of different comorbidity lookback periods when predicting in-hospital mortality for patients who underwent percutaneous coronary intervention. Methods : This was a retrospective study on patients aged 40 years and older who underwent percutaneous coronary intervention. To distinguish comorbidity from complications, the records of diagnosis were drawn from the National Health Insurance Database excluding diagnosis that admitted to the hospital. C-statistic values were used as measures for in comparing the predictability of comorbidity measures with lookback period, and a bootstrapping procedure with 1,000 replications was done to determine approximate 95% confidence interval. Results : Of the 61,815 patients included in this study, the mean age was 63.3 years (standard deviation: ${\pm}$10.2) and 64.8% of the population was male. Among them, 1,598 2.6%) had died in hospital. While the predictive ability of the Elixhauser's comorbidity and comorbidity selection was better than that of the Charlson comorbidity index, there was no significant difference among the three comorbidity measurements. Although the prevalence of comorbidity increased in 3 years of lookback periods, there was no significant improvement compared to 1 year of a lookback period. Conclusions : In a health outcome study for patients who underwent percutaneous coronary intervention using National Health Insurance Database, the Charlson comorbidity index was easy to apply without significant difference in predictability compared to the other methods. The one year of observation period was adequate to adjust the comorbidity. Further work to select adequate comorbidity measurements and lookback periods on other diseases and procedures are needed.

• 문화기술의 융합
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• 제6권4호
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• pp.289-294
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• 2020

기능성 위장장애는 Helicobacter pylori 감염 및 비 스테로이드성 항염증제의 사용 등의 원인으로 발생하는 소화기 계통 질환이다. 그동안 기능성 위장장애의 위험요인에 대한 많은 연구들이 수행되어졌으나, 한국인에 대한 기능성 위장장애 예측 모델 제시에 대한 연구는 없는 실정이다. 따라서 본 연구의 목적은 중년 및 노년층을 대상으로 인구학적정보, 비만정보, 혈액정보, 영양성분 정보를 바탕으로 머신러닝을 이용하여 기능성위장장애 예측 모델을 구현하고 평가하는 것이다. 모델생성을 위해 wrapper-based variable selection 메소드와 naive Bayes 알고리즘이 사용되었다. 여성 예측 모델의 분류 정확도는 0.712의 the area under the receiver operating characteristics curve(AUC) 값을 나타냈고, 남성에서는 여성보다 낮은 0.674의 AUC값이 나타났다. 이러한 연구결과는 향후 중년 및 노년층의 위장장애 질환의 예측과 예방에 활용될 수 있다.

• 응용통계연구
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• 제28권3호
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• pp.407-415
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• 2015

단순 베이즈 분류($Na{\ddot{i}}ve$ Bayes classification)는 출력변수가 주어졌을 때 입력변수들이 조건부 독립이라는 가정에 기반한다. 단순 베이즈 가정은 비현실적이지만 고차원의 확률 추정 문제를 일련의 일차원 확률 추정 문제로 단순화 시킨다는 장점이 있으며, 특히 스팸 메일 필터링, 추천 시스템(recommendation system) 등 방대한 데이터를 다루는 분야야에서 흔히 사용된다. 본 논문에서는 입력변수와 출력변수간의 카이제곱 통계량에 기반한 변수선택법을 제안한다. 이 방법은 단순 베이즈 분류의 장점인 데이터 처리 및 계산의 단순성을 유지하면서도 설명력이 있는 변수를 선택할 수 있으며 SNP(single nucleotide polymorphism)에 의한 질병의 분류 등의 초고차원 혹은 빅데이터에서 유용할 것으로 기대된다.

• 대한의용생체공학회:의공학회지
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• 제32권2호
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• pp.134-143
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• 2011

The selection of meaningful clinical tests and its reference values from a high-dimensional clinical data with imbalanced class distribution, one class is represented by a large number of examples while the other is represented by only a few, is an important issue for differential diagnosis between similar diseases, but difficult. For this purpose, this study introduces methods based on the concepts of both discernibility matrix and function in rough set theory (RST) with two discretization approaches, equal width and frequency discretization. Here these discretization approaches are used to define the reference values for clinical tests, and the discernibility matrix and function are used to extract a subset of significant clinical tests from the translated nominal attribute values. To show its applicability in the differential diagnosis problem, we have applied it to extract the significant clinical tests and its reference values between normal (N = 351) and abnormal group (N = 101) with either cholecystitis or cholelithiasis disease. In addition, we investigated not only the selected significant clinical tests and the variations of its reference values, but also the average predictive accuracies on four evaluation criteria, i.e., accuracy, sensitivity, specificity, and geometric mean, during l0-fold cross validation. From the experimental results, we confirmed that two discretization approaches based rough set approximation methods with relative frequency give better results than those with absolute frequency, in the evaluation criteria (i.e., average geometric mean). Thus it shows that the prediction model using relative frequency can be used effectively in classification and prediction problems of the clinical data with imbalanced class distribution.

• Parasites, Hosts and Diseases
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• 제61권2호
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• pp.216-224
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• 2023

In several schistosomiasis-endemic countries, the prevalence has remained high in some areas owing to reinfection despite repeated mass drug administration (MDA) interventions; these areas are referred to as persistent hot spots. Identifying hotspots is critical for interrupting transmission. This study aimed to determine an effective means of identifying persistent hot spots. First, we investigated the differences between Schistosoma haematobium and Schistosoma mansoni prevalence among school-aged children (SAC) estimated by a community-based survey, for which local key informants purposively selected communities, and a randomly sampled school-based survey. A total of 6,225 individuals residing in 60 villages in 8 districts of North Kordofan, Blue Nile, or Sennar States, Sudan participated in a community-based survey in March 2018. Additionally, the data of 3,959 students attending 71 schools in the same 8 districts were extracted from a nationwide school-based survey conducted in January 2017. The community-based survey identified 3 districts wherein the prevalence of S. haematobium or S. mansoni infection among SAC was significantly higher than that determined by the randomly sampled school survey (e.g., S. haematobium in the Sennar district: 10.8% vs. 1.1%, P<0.001). At the state level, the prevalence of schistosomiasis among SAC, as determined by the community-based survey, was consistently significantly higher than that determined by the school-based survey. Purposeful selection of villages or schools based on a history of MDA, latrine coverage, open defecation, and the prevalence of bloody urine improved the ability for identifying persistent hot spots.

• Korean Journal of Acupuncture
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• 제34권2호
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• pp.88-99
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• 2017

Objectives : Saam acupuncture initiated by Saamdoin in $17^{th}$ century is one of the most widely adopted acupuncture techniques used by Korean medical doctors in clinic. Our study aimed to analyze the application of the Saam acupuncture method to pain diseases based on the literature data. Methods : Based on the contents described in "(Do Hae Kyo Kam) Saam's acupuncture method", the texts related to pain condition were analyzed. The frequency of prescription of Saam acupuncture method was analyzed, and then the relationships between each acupoint were visualized by network analysis and hierarchical cluster analysis for the quantitative aspect. Results and conclusions: In our study, Lung tonifying and Liver tonifying acupuncture were the most frequently used method for the treatment of pain disease. As the acupoints, BL66 and SI5 were used the most frequently. It was found that visceral pattern identification was considered as the most important factor in the selection of the Saam acupuncture method. Network analysis and hierarchical clustering analysis showed that each acupoint was closely related to other acupoints, and most of them were connected more closely according to the method of Saam acupuncture operation. The experiential prescriptions of Saam acupuncture were classified as an independent group. In the future, fundamental research on the principle of Saam acupuncture method is needed for the various diseases, and research for the clinical efficacy and the mechanism of Saam acupuncture method should be preceded.

• Journal of Korean Neurosurgical Society
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• 제51권6호
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• pp.350-358
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• 2012

Objective : Life expectancy for humans has increased dramatically and with this there has been a considerable increase in the number of patients suffering from lumbar spine disease. Symptomatic lumbar spinal disease should be treated, even in the elderly, and surgical procedures such as fusion surgery are needed for moderate to severe lumbar spinal disease. However, various perioperative complications are associated with fusion surgery. The aim of this study was to examine perioperative complications and assess risk factors associated with lumbar spinal fusion, focusing on geriatric patients at least 70 years of age in the Republic of Korea. Methods : We retrospectively investigated 489 patients with various lumbar spinal diseases who underwent lumbar spinal fusion surgery between 2003 and 2007 at our institution. Three fusion procedures and the number of fused segments were analyzed in this study. Chronic diseases were also evaluated. Risk factors for complications and their association with age were analyzed. Results : In this study, 74 patients experienced complications (15%). The rate of perioperative complications was significantly higher in patients 70 years of age or older than in other age groups (univariate analysis, p=0.001; multivariate analysis, p=0.004). However, perioperative complications were not significantly associated with the other factors tested (sex, comorbidities, operation procedures, fusion segments involved). Conclusion : Increasing age was an important risk factor for perioperative complications in patients undergoing lumbar spinal fusion surgery whereas other factors were not significant. We recommend good clinical judgment and careful selection of geriatric patients undergoing lumbar spinal fusion surgery.