• Radiation Oncology Journal
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• 제4권2호
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• pp.89-97
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• 1986

Co-60 치료기로 마우스 전신에 다분할조사(단일 2, 3, 4, 5, 8, 10, 12, 16회 분할 조사)후 공장소 낭선세포측정법으로 소낭선세포의 재생능력에 대한 선량반응 곡선을 작성하고, 단일선량생존곡선을 분석하여 다음과 같은 결론을 얻었다. 1) 분할조사회수가 증가함에 따라 생존곡선은 고선량으로 이동하고 경사도는 점차 낮아졌다. 2) 단일선량생존곡선에서 Dq=460 cGy로 비교적 broad shoulder를 가지며 initial slope$(^1Do)$는 475 cGy이 었다. 3) $180\~450cGy$까지 분할 조사한 경우 분할조사간격당 평균회복선량은 분할조사선량의 약 $50\%$이었다. 4) 등가효과를 나타내는 분할조사선량과 이에 해당하는 총선량의 역수를 산출하여 선형회귀분석한 $\alpha/\beta$ 값은 8.3Gy로 조기반응조직의 범위(6-l4Gy)에 속하였다. 5) LQ model은 방사선치료에 사용되고 있는 모든 선량에 적용이 가능하고, $\alpha,\;\beta$ 두 요소만 필요하므로, 실질적으로 편리하게 적응할 수 없다. 다분할조사에 대한 stem cell의 반응을 이해함으로써, 실제방사선치료시 위장관에 대한 급성손상을 극소화시키는 변형된 치료방법을 도입하고 다른 조직에도 응용할 수 있는 방사선생물학적 자료가 될 것으로 사료된다.

• Annals of Surgical Treatment and Research
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• 제95권5호
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• pp.286-296
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• 2018

Purpose: Sentinel lymph node (SLN) biopsy (SLNB) is widely accepted for staging of melanoma patients. It has been shown that clinico-pathological features such as Breslow thickness, ulceration, age, and sex are better predictors of relapse and survival than SLN status alone. The aims of this study were to evaluate the long-term (10-year) prognostic impact of SLNB and to determine predictive factors associated with SLN metastasis, relapse, and melanoma specific mortality (MSM). Methods: This was a prospective observational study on 289 consecutive patients with primary cutaneous melanoma who underwent SLNB from January 2000 to December 2007, and followed until January 2014, at an Italian academic hospital. Results: SLN was positive in 64 patients (22.1%). The median follow-up was 116 months (79-147 months). Tenyear disease-free survival and melanoma specific survival were poor in patients with positive SLN (58.7% and 66.4%, respectively). Only the increasing Breslow thickness resulted independently associated to an increased risk of SLN metastasis. Cox regression analysis showed that a Breslow thickness >2 mm was an independent predictor of relapse, and male sex and Breslow thickness >2 mm was a predictor of MSM. At 10 years, SLN metastasis was not significantly associated to either relapse or MSM. Conclusion: After the fifth year of follow-up, SLN metastasis is not an independent predictive factor of relapse or mortality which are mainly influenced by the characteristics of the primary tumor and of the patient. Patients with a Breslow thickness >2 mm regardless of the SLN status should be considered at high risk for 10-year relapse and mortality.

• Korean Journal of Radiology
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• 제23권3호
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• pp.370-380
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• 2022

Objective: To compare pneumonic-type invasive mucinous adenocarcinoma (pIMA) confined to a single lobe with clinical T2, T3, and T4 stage lung cancer without pathological node metastasis regarding survival after curative surgery and to identify prognostic factors for pIMA. Materials and Methods: From January 2010 to December 2017, 41 patients (15 male; mean age ± standard deviation, 66.0 ± 9.9 years) who had pIMA confined to a single lobe on computed tomography (CT) and underwent curative surgery were identified in two tertiary hospitals. Three hundred and thirteen patients (222 male; 66.3 ± 9.4 years) who had non-small cell lung cancer (NSCLC) without pathological node metastasis and underwent curative surgery in one participating institution formed a reference group. Relapse-free survival (RFS) and overall survival (OS) were calculated using the Kaplan-Meier method. Cox proportional hazard regression analysis was performed to identify factors associated with the survival of patients with pIMA. Results: The 5-year RFS and OS rates in patients with pIMA were 33.1% and 56.0%, respectively, compared with 74.3% and 91%, 64.3% and 71.8%, and 46.9% and 49.5% for patients with clinical stage T2, T3, and T4 NSCLC in the reference group, respectively. The RFS of patients with pIMA was comparable to that of patients with clinical stage T4 NSCLC and significantly worse than that of patients with clinical stage T3 NSCLC (p = 0.012). The differences in OS between patients with pIMA and those with clinical stage T3 or T4 NSCLC were not significant (p = 0.11 and p = 0.37, respectively). In patients with pIMA, the presence of separate nodules was a significant factor associated with poor RFS and OS {unadjusted hazard ratio (HR), 4.66 (95% confidence interval [CI], 1.95-11.11), p < 0.001 for RFS; adjusted HR, 4.53 (95% CI, 1.59-12.89), p = 0.005 for OS}. Conclusion: The RFS of patients with pIMA was comparable to that of patients with clinical stage T4 lung cancer. Separate nodules on CT were associated with poor RFS and OS in patients with pIMA.

• Journal of Chest Surgery
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• 제57권5호
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• pp.467-476
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• 2024

Background: This study aimed to examine the clinical implications of selective station 4L lymph node dissection (S4L-LND) on survival in non-small cell lung cancer (NSCLC) and to evaluate its potential advantages. Methods: We enrolled patients with primary left-sided NSCLC who underwent upfront video-assisted thoracoscopic surgery with R0 resection including lobectomy and segmentectomy, with or without S4L-LND, at our institution between January 2007 and December 2021. Following 1:1 propensity score matching (PSM), we compared overall survival (OS) and recurrence-free survival (RFS) between patients with and without S4L-LND. Results: The study included 2,601 patients, of whom 1,126 underwent S4L-LND and 1,475 did not. PSM yielded 1,036 patient pairs. Among those who underwent S4L-LND, 87 (7.7%) exhibited S4L-LN involvement. Neither OS (p=0.12) nor RFS (p=0.24) differed significantly between matched patients with and without S4L-LND. In patients with S4L-LN involvement, metastases were more common in the left upper lobe (LUL) than in the left lower lobe (LLL) (3.6% vs. 2.0%, p=0.061). Metastasis became significantly more frequent with more advanced clinical N (cN) stage (cN0, 2.3%; cN1, 5.8%; cN2, 32.6%; p<0.001). Multivariate logistic regression analysis revealed that cN stage and tumor location were independently associated with S4L-LN involvement (p<0.001 for both). Conclusion: OS and RFS did not differ significantly between matched patients with and without S4L-LND. Among participants with S4L-LN involvement, metastases occurred more frequently in the LUL than the LLL, and their incidence increased significantly with more advanced cN stage. Thus, patients with LUL or advanced cN lung cancers may benefit from S4L-LND.

• 대한의생명과학회지
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• 제17권3호
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• pp.267-271
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• 2011

P19 cells are pluripotent embryonal carcinoma cells and can be differentiated into neuronal cell type by treatment with retinoic acid (RA) and aggregation culture. Cannabinoids are the active components of Cannabis sativa and they have diverse pharmacologic activities, such as pain control, anti-inflammatory effects, neuro-protection effects and tumor regression. Cannabinoids also involved in neuronal proliferation, migration, differentiation and survival in developing brain. Here, we studied the role of cannabinoids on neuronal differentiation of P19 cells. Treatment with cannabinoids increased the neuronal differentiation induced by RA and also promoted transcriptional activity of neurogenin 1, key transcription factor for neuronal differentiation of P19 cells. These results suggest that the cannabinoids can accelerate neuronal differentiation of P19 cells.

• Journal of the Korean Data and Information Science Society
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• 제16권4호
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• pp.1017-1026
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• 2005

We consider the problem of modeling count data where the observation period is determined by the survival time of the individual under study. We assume random effects or frailty model to allow for a possible association between the death times and the counts. We assume that, given a random effect, the death times follow a Weibull distribution with a rate that depends on some covariates. For the counts, given the random effect, a Poisson process is assumed with the intensity depending on time and the covariates. A gamma model is assumed for the random effect. Maximum likelihood estimators of the model parameters are obtained. The model is applied to data set of patients with breast cancer who received a bone marrow transplant. A model for the time to death and the number of supportive transfusions a patient received is constructed and consequences of the model are examined.

• 대한간호학회지
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• 제48권5호
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• pp.545-553
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• 2018

Purpose: The increasing survival rate of colorectal cancer demands various nursing interventions and continuous care for patients to adapt to their psychosocial daily lives. The purpose of this study was to identify factors associated with psychosocial adjustment in colorectal cancer survivors. Methods: A cross-sectional descriptive study with face-to-face interviews was conducted of 156 colorectal cancer survivors after surgery visiting an outpatient cancer clinic at a tertiary hospital in S city, Korea. Posttraumatic growth, health-promoting behavior, length of treatment, difficulty in activities of daily living, and having a stoma were entered into the linear regression model. Results: The strongest factor influencing the level of psychosocial adjustment was health-promoting behavior (${\beta}=.33$, p<.001), followed by difficulty in activities of daily living (${\beta}=-.24$, p=.001), posttraumatic growth (${\beta}=.20$, p=.004), and having a stoma (${\beta}=-.19$, p=.004). Conclusion: Nursing interventions for psychosocial adjustment in colorectal cancer survivors need to include the contents for posttraumatic growth, as well as health-promoting behavior, and activities of daily living.

• 응용통계연구
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• 제25권6호
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• pp.947-958
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• 2012

When modeling event times in biomedical studies, the outcome might be incompletely observed. In this paper, we assume that the outcome is recorded as current status failure time data. Despite well-developed literature the routine practical use of many current status data modeling methods remains infrequent due to the lack of specialized statistical software, the difficulty to assess model goodness-of-fit, as well as the possible loss of information caused by covariate grouping or discretization. We propose a model based on pseudo-observations that is convenient to implement and that allows for flexibility in the choice of the outcome. Parameter estimates are obtained based on generalized estimating equations. Examples from studies in bile duct hyperplasia and breast cancer in conjunction with simulated data illustrate the practical advantages of this model.

• Biomolecules & Therapeutics
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• 제8권3호
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• pp.235-240
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• 2000

Antitumor effect of LC43, a protein-bound ploysaccharide (M.W. 43 kDa) that was purified from intergeneric protoplast fusant of Lentinus edodes and Coriolus versicolor, was elucidated against mouse sarcoma 180 cell in vitro and in vivo. By injecting LC43 into ICR mice bearing solid or ascitic sarcoma 180, tumor regression and survival rates were investigated. To examine the effects of LC43 on immunopotentiation activity. immunoorgan weight, B cell differentiation, T cell activity and macrophage activation were determined. LC43 showed antitumor effects against both solid tumor and ascitic tumor of sarcoma 180. It did not change significantly the immunoorgan weight but potentiated immune responses such as B cell differentiation and the release of superoxide anion from macrophages. These results suggest that the protein-bound polysaccharide of LC43 exhibited antitumor activities through the activation of immune-related cells and acted as an immunmodulator.

• Communications for Statistical Applications and Methods
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• 제26권3호
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• pp.315-323
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• 2019

Panel data sets have recently been developed in various areas, and many recent studies have analyzed panel, or longitudinal data sets. Often a dichotomous dependent variable occur in survival analysis, biomedical and epidemiological studies that is analyzed by a generalized linear mixed effects model (GLMM). The most common estimation method for the binary panel data may be the maximum likelihood (ML). Many statistical packages provide ML estimates; however, the estimates are computed from numerically approximated likelihood function. For instance, R packages, pglm (Croissant, 2017) approximate the likelihood function by the Gauss-Hermite quadratures, while Rchoice (Sarrias, Journal of Statistical Software, 74, 1-31, 2016) use a Monte Carlo integration method for the approximation. As a result, it can be observed that different packages give different results because of different numerical computation methods. In this note, we discuss the pros and cons of numerical methods compared with the exact computation method.