• Journal of the Korean Data and Information Science Society
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• 제22권3호
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• pp.605-612
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• 2011

In multi-center randomized clinical trial the treatment eect may be changed over centers. It is thus important to investigate the heterogeneity in treatment eect between centers. For this, uncorrelated random-eect models assuming independence between random-eect terms have been often used, which may be a strong assumption. In this paper we propose a correlated frailty modelling approach of investigating such heterogeneity using the hierarchical-likelihood method when the outcome is time-to-event. In particular, we show how to construct a proper prediction interval for frailty, which explores graphically the potential heterogeneity for a treatment-by-center interaction term. The proposed method is illustrated via numerical studies based on data from the design of a multi-center clinical trial.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2005년도 춘계학술대회
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• pp.200-201
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• 2005

• Korean Journal of Acupuncture
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• 제24권3호
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• pp.33-45
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• 2007

Background : Hot flushes are general postmenopausal symptoms which about 75% of climacteric women undergo. They affect hotness, perspirations, systemic weakness, panic disorders, insomnia. Acupuncture is effective in alleviating hot flushes in practice. Assessment effectiveness and safety of acupuncture in hot flushes would be needed through multi-center trial. Objectives : Purpose of this study is to develope the protocol of effects of acupuncture on hot flushes, a postmenopausal symptom in climacteric women. Methods & Results : It will be a multi-centered, randomized, sham controlled, comparative trial. It will be performed by Good Clinical Practice after approval of Institutional Review Board. Selection criteria will be set according those of FDA above moderate degree. There will be a notice on concomitant medication, other herbs, dietary supplements. Superficial needling on sham points will be used for control group. Treatment period will be 8 weeks with 12 weeks' follow up. Some questionnaire scale will be used as the primary and secondary outcome. Conclusions : The clinical trials based on this protocol will be performed.

• 한국콘텐츠학회논문지
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• 제11권1호
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• pp.350-356
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• 2011

본 연구의 목적은 전자적 임상시험 데이터 관리를 위한 설계 시 시간적 요인에 주목하여 시스템의 효율성을 검증해 보고자 함이다. 임상시험 데이터 관리에 대한 관심이 커지고 있고 시스템 도입이 활발한 데 반해, 실제 효율성 측정에 관한 실증연구는 많지 않다. 특히 국내의 경우 임상시험 데이터 관리를 위한 전산화 도입률 조차 낮은 실정이다. 본 연구는 전자적 임상시험 데이터 관리에 대한 중요성 인식 확산을 위하여 전자적 시스템의 효과에 대한 실증연구를 시도하였으며, 시간효율성 측정지표를 활용하여 다기관 임상시험 사례의 자료를 분석하였다. 연구결과로서 전자적 시스템으로의 전환이 임상시험 전체 프로세스에 제공할 수 있는 시간 측면에서의 효율성을 검증하였으며 전자적 임상시험 데이터 관리 시스템의 활용 효과를 분석하기 위한 국내 첫 실증연구의 시도라는 의미가 있다. 나아가 전략적 데이터 관리 수립 및 임상단계 별 비교연구 등 향후 다양한 비교 연구들의 초석이 될 것이다.

• Communications for Statistical Applications and Methods
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• 제25권3호
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• pp.321-328
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• 2018

In clinical trials with repeated measurements, the time-averaged difference (TAD) may provide a more powerful evaluation of treatment efficacy than the rate of changes over time when the treatment effect has rapid onset and repeated measurements continue across an extended period after a maximum effect is achieved (Overall and Doyle, Controlled Clinical Trials, 15, 100-123, 1994). The sample size formula has been investigated by many researchers for the evaluation of TAD in two treatment groups. For the evaluation of TAD in multi-arm trials, Zhang and Ahn (Computational Statistics & Data Analysis, 58, 283-291, 2013) and Lou et al. (Communications in Statistics-Theory and Methods, 46, 11204-11213, 2017b) developed the sample size formulas for continuous outcomes and count outcomes, respectively. In this paper, we derive a sample size formula to evaluate the TAD of the repeated binary outcomes in multi-arm trials using the generalized estimating equation approach. This proposed sample size formula accounts for various correlation structures and missing patterns (including a mixture of independent missing and monotone missing patterns) that are frequently encountered by practitioners in clinical trials. We conduct simulation studies to assess the performance of the proposed sample size formula under a wide range of design parameters. The results show that the empirical powers and the empirical Type I errors are close to nominal levels. We illustrate our proposed method using a clinical trial example.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2006년도 The 5th Biannual Meeting of Pacific Rim Society for Fertility and Sterility
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• pp.66-68
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• 2006

• 대한한방내과학회지
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• 제45권1호
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• pp.1-10
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• 2024

Objectives: This study investigated the pattern identification (PI) and clinical index of Parkinson's disease (PD) for personalized diagnosis and treatment. Methods: This prospective observational multi-center study recruited 100 patients diagnosed with PD from two Korean medicine hospitals. To cluster new subtypes of PD, items on a PI questionnaire (heat and cold, deficiency and excess, visceral PI) were evaluated along with pulse and tongue analysis. Gait analysis was performed and blood and feces molecular signature changes were assessed to explore biomarkers for new subtypes. In addition, unified PD rating scale II and III scores and the European quality of life 5-dimension questionnaire were assessed. Results: The clinical index obtained in this study analyzed the frequency statistics and hierarchical clustering analysis to classify new subtypes based on PI. Moreover, the biomarkers and current status of herbal medicine treatment were analyzed using the new subtypes. The results provide comprehensive data to investigate new subtypes and subtype-based biomarkers for the personalized diagnosis and treatment of PD patients. Ethical approval was obtained from the medical ethics committees of the two Korean medicine hospitals. All amendments to the research protocol were submitted and approved. Conclusions: An objective and standardized diagnostic tool is needed for the personalized treatment of PD by traditional Korean medicine. Therefore, we developed a clinical index as the basis for the PI clinical evaluation of PD. Trial Registration: This trial is registered with the Clinical Research Information Service (CRIS) (KCT0008677)

• Journal of Gastric Cancer
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• 제12권1호
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• pp.7-12
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• 2012

More than ten years have passed since the sentinel node (SN) concept for gastric cancer surgery was first discussed. Less invasive modified surgical approaches based on the SN concept have already been put into practice for malignant melanoma and breast cancer, however the SN concept is not yet placed in a standard position in gastric cancer surgery even after two multi-institutional prospective clinical trials, the Japan Clinical Oncology Group trial (JCOG0302) and the Japanese Society for Sentinel Node Navigation Surgery (SNNS) trial. What is the problem in the clinical application of the SN concept to gastric cancer surgery? There is no doubt that we need reliable indicator(s) to determine with certainty the absence of metastasis in the lymph nodes in order to avoid unnecessary lymphadenectomy. There are several matters of debate in performing the actual procedure, such as the type of tracer, the site of injection, how to detect and harvest, how to detect metastases of SNs, and learning period. These issues have to be addressed further to establish the most suitable procedure. Novel technologies such as indocyanine green (ICG) fluorescence imaging and one-step nucleic acid amplification (OSNA) may overcome the current difficulties. Once we know what the problems are and how to tackle them, we can pursue the goal.

• Genomics & Informatics
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• 제16권3호
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• pp.52-58
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• 2018

In this report, we present a case study of how pharmacogenomics and pharmacometabolomics can be useful to characterize safety and pharmacokinetic profiles in early phase new drug development clinical trials. During conducting a first-in-human trial for a new molecular entity, we were able to determine the mechanism of dichotomized variability in plasma drug concentrations, which appeared closely related to adverse drug reactions (ADRs) through integrated omics analysis. The pharmacogenomics screening was performed from whole blood samples using the Affymetrix DMET (Drug-Metabolizing Enzymes and Transporters) Plus microarray, and confirmation of genetic variants was performed using real-time polymerase chain reaction. Metabolomics profiling was performed from plasma samples using liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. A GSTM1 null polymorphism was identified in pharmacogenomics test and the drug concentrations was higher in GSTM1 null subjects than GSTM1 functional subjects. The apparent drug clearance was 13-fold lower in GSTM1 null subjects than GSTM1 functional subjects (p < 0.001). By metabolomics analysis, we identified that the study drug was metabolized by cysteinylglycine conjugation in GSTM functional subjects but those not in GSTM1 null subjects. The incidence rate and the severity of ADRs were higher in the GSTM1 null subjects than the GSTM1 functional subjects. Through the integrated omics analysis, we could understand the mechanism of inter-individual variability in drug exposure and in adverse response. In conclusion, integrated multi-omics analysis can be useful for elucidating the various characteristics of new drug candidates in early phase clinical trials.

• 동의생리병리학회지
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• 제28권1호
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• pp.94-101
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• 2014

We studied to investigate the erythema reduction effects generated by Gagam-Jawoonaek(GJ) application(appl.) after UV exposure. Twenty women in their twenties to fifties with no skin diseases were recruited. We exposed UV as a 6 subsites on the left upper arm of subjects using multi-port solar simulator. After setting Gagam-Jawoonaek(GJ) application(appl.) subsites and non-appl. subsites, we measured erythema degrees($a^*$ values) of the subsites using spectrophotometer. We measured $a^*$ values four times(before UV exposure, before application of GJ, twenty-four and forty-eight hours after first application of GJ). We analyzed data using student's t-test. After UV exposure, $a^*$ values on the left upper arm increased. Twenty-four hours after first GJ treat., the changes of $a^*$ value on GJ treat. subsites($1.22{\pm}0.13AU$) were bigger than GJ non-treat. subsites($1.04{\pm}0.12AU$), but there was no statistically significance. Forty-eight hours after first GJ treat., the changes of $a^*$ value on GJ treat. subsites($1.95{\pm}0.11AU$) were bigger than GJ non-treat. subsites($1.58{\pm}0.13AU$), a statistically significance. Gagam-Jawoonaek could decrease erythema by UV exposure.