• BMB Reports
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• v.50 no.11
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• pp.572-577
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• 2017

In most clinical applications, human mesenchymal stem cells (hMSCs) are expanded in large scale before their administration. Prolonged culture in vitro results in cellular senescence-associated phenotypes, including accumulation of reactive oxygen species (ROS) and decreased cell viabilities. Profiling of stem cell-related genes during in vitro expansion revealed that numerous canonical pathways were significantly changed. To determine the effect of selenocysteine (Sec), a rare amino acid found in several antioxidant enzymes, on the replicative senescence in hMSCs, we treated senescent hMSCs with Sec. Supplementation of Sec in the culture medium in late-passage hMSCs reduced ROS levels and improved the survival of hMSCs. In addition, a subset of key antioxidant genes and Sec-containing selenoproteins showed increased mRNA levels after Sec treatment. Furthermore, ROS metabolism and inflammation pathways were predicted to be downregulated. Taken together, our results suggest that Sec has antioxidant effects on the replicative senescence of hMSCs.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.198-206
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• 2015

Purpose: We evaluated the prognostic factors and clinical outcomes of 56 patients with vulvar cancer treated with curative radiotherapy (RT) or concurrent chemoradiotherapy. Materials and Methods: Overall survival (OS) and disease-free survival (DFS) were assessed retrospectively. Prognostic factors evaluated included age, International Federation of Gynecology and Obstetrics (FIGO) stage, TNM classification, tumor size, treatment modality, RT duration, and RT field. The association between the tumor human papillomavirus (HPV) status and survival was analyzed in 35 patients. Results: During the median follow-up of 2.8 years (range, 0.3 to 18.9 years), 21 patients (37.5%) experienced treatment failure. Fifteen patients (27%) had local failure: nine (16%) local failure only, three (5%) locoregional failure, two (4%) local and distant failure, and one (2%) locoregional and distant failure. Of 56 patients, seven (13%) had persistent disease at the first follow-up at 2 months and all but one died within a year after completing RT. The 5-year OS and DFS were 51.6% and 44.0%, respectively. In multivariate analysis, clinical size ${\geq}3$ cm predicted a poor prognostic factor for DFS (p = 0.040) and age (${\geq}70years$) was poor prognostic for DFS (p = 0.032) and OS (p = 0.048). Patients with HPV-positive tumors tended to have better 5-year OS and DFS, but the differences were not significant statistically. Conclusion: Clinical size ${\geq}3$ cm was a significant prognostic factor for DFS. However, age was the most important prognostic factor for DFS and OS in patients treated with curative RT. Further studies are needed to determine which treatment should be considered for old age ${\geq}70years$.

• Journal of Korea Water Resources Association
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• v.42 no.6
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• pp.457-464
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• 2009

This paper proposes methodologies for analyzing the accuracy of the proportional hazards model in predicting consecutive break times of water mains and estimating the time interval for economical water main replacement. By using the survival functions that are based on the proportional hazards models a criterion for the prediction of the consecutive pipe breaks is determined so that the prediction errors are minimized. The criterion to predict pipe break times are determined as the survival probability of 0.70 and only the models for the third through the seventh break are analyzed to be reliable for predicting break times for the case study pipes. Subsequently, the criterion and the estimated lower and upper bound survival functions of consecutive breaks are used in predicting the lower and upper bounds of the 95% confidence interval of future break times of an example water main. Two General Pipe Break Prediction Models(GPBMs) are estimated for an example pipe using the two series of recorded and predicted lower and upper bound break times. The threshold break rate is coupled with the two GPBMs and solved for time to obtain the economical replacement time interval.

• Radiation Oncology Journal
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• v.8 no.1
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• pp.65-71
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• 1990

Between January,1974 and December 1980, fifty eight patients with locoregional recurrent breast carcinoma who did not have evidence of distant metastasis after initial treatment of surgery with or without adjuvant chemotherapy were treated with radiation therapy. Among them, five patients were excluded from this study because of incomplete record or incomplete treatment. The 5-year overall survival and disease free survival from the time of locoregional recurrence was $27\%\;and\;15\%$ respectively. In univariate analysis of prognostic variables, the clinical stage at initial diagnosis, recur duration, number of recurrence sites, size of recurrences, response to the treatment, remission duration were all found to have no significant effect on survival or disease free survival. On the other hand, menopausal status at initial diagnosis, number of positive node at initial surgery, whether or not the use of adjuvant chemotherapy after initial mastectomy had definite prognositc significance. In multivariate analysis of prognostic variables, remission duration, menopausal status at diagnosis, number of axillary node at mastectomy had definite prognostic significance. On the other hand, remission duration more than 12 months, premenopaus at initial mastectomy, less than four positive axillary lymph nodes at mastectomy predicted a good prognosis.

• Radiation Oncology Journal
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• v.38 no.2
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• pp.99-108
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• 2020

Purpose: The probability of recurrence of cancer after adjuvant or definitive radiotherapy in patients with human papillomavirus-negative (HPV(-)) head and neck squamous cell carcinoma (HNSCC) varies for each patient. This study aimed to identify and validate radiation sensitivity signature (RSS) of patients with HPV(-) HNSCC to predict the recurrence of cancer after radiotherapy. Materials and Methods: Clonogenic survival assays were performed to assess radiosensitivity in 14 HNSCC cell lines. We identified genes closely correlated with radiosensitivity and validated them in The Cancer Genome Atlas (TCGA) cohort. The validated RSS were analyzed by ingenuity pathway analysis (IPA) to identify canonical pathways, upstream regulators, diseases and functions, and gene networks related to radiosensitive genes in HPV(-) HNSCC. Results: The survival fraction of 14 HNSCC cell lines after exposure to 2 Gy of radiation ranged from 48% to 72%. Six genes were positively correlated and 35 genes were negatively correlated with radioresistance, respectively. RSS was validated in the HPV(-) TCGA HNSCC cohort (n = 203), and recurrence-free survival (RFS) rate was found to be significantly lower in the radioresistant group than in the radiosensitive group (p = 0.035). Cell death and survival, cell-to-cell signaling, and cellular movement were significantly enriched in RSS, and RSSs were highly correlated with each other. Conclusion: We derived a HPV(-) HNSCC-specific RSS and validated it in an independent cohort. The outcome of adjuvant or definitive radiotherapy in HPV(-) patients with HNSCC can be predicted by analyzing their RSS, which might help in establishing a personalized therapeutic plan.

• Tuberculosis and Respiratory Diseases
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• v.49 no.2
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• pp.179-188
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• 2000

Background : The decision to institute mechanical ventilation for patients with COPD is very difficult. The accurate information regarding weaning success and long-term survival will improve communication with patients and family and enhance informed consent. The aims of this study are to describe outcomes and identify variables associated with survival for patients experiencing mechanical ventilation with an acute respiratory failure of COPD. Methods : The 53 cases of mechanical ventilation in the intensive care unit in the National Medical Center from 1989 to 1998 were included. Data were collected retrospectively from medical records. Weaning success rate and 3 month and 1 year survival rates were estimated. Factors associated with weaning success and survival were determined. Results : Weaning sucess was 55%. For success group with 29 cases, 3 months survival rate was 61% and 1 year survival rate 37%. APACHE II scores in weaning success group were significantly lower than those in the failure group. Factors such as age, sex, comorbid-illnes. previous steroid use, causes of respiratory failure, RVH or arrhythmia on EKG, serum albumin level, arterial blood pH, $PaO_2$, $PaCO_2$, $FEV_1$ duration of mechanical ventilation and steroid use during mechanical ventilation were not associated with weaning success. Only age and serum albumin level were associated with 3 month and 1 year survival. No COPD patients of age more than 75 years and serum albumin level less than 3g/dl had survived at 1 year after weaning success. Conclusion : While weaning success from mechanical ventilation can be predicted by APACHE II score in COPD patients, long-term outcomes of survivors may be influenced by nutritional status and age.

• Journal of Chest Surgery
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• v.45 no.2
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• pp.110-115
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• 2012

Background: Pneumonectomy remains the ultimate curative treatment modality for destroyed lung caused by tuberculosis despite multiple risks involved in the procedure. We retrospectively evaluated patients who underwent pneumonectomy for treatment of sequelae of pulmonary tuberculosis to determine the risk factors of early and long-term outcomes. Materials and Methods: Between January 1980 and December 2008, pneumonectomy or pleuropneumonectomy was performed in 73 consecutive patients with destroyed lung caused by tuberculosis. There were 48 patients with empyema (12 with bronchopleural fistula [BPF]), 11 with aspergilloma and 7 with multidrug resistant tuberculosis. Results: There were 5 operative mortalities (6.8%). One patient had intraoperative uncontrolled arrhythmia, one had a postoperative cardiac arrest, and three had postoperative respiratory failure. A total of 29 patients (39.7%) suffered from postoperative complications. Twelve patients (16.7%) were found to have postpneumonectomy empyema (PPE), 4 patients had wound infections (5.6%), and 7 patients required re-exploration due to postoperative bleeding (9.7%). The prevalence of PPE increased in patients with preoperative empyema (p=0.019). There were five patients with postoperative BPF, four of which occurred in right-side operation. The only risk factor for BPF was the right-side operation (p=0.023). The 5- and 10-year survival rates were 88.9% and 76.2%, respectively. The risk factors for late deaths were old age (${\geq}50$ years, p=0.02) and low predicted postoperative forced expiratory volume in one second (FEV1) (< 1.2 L, p=0.02). Conclusion: Although PPE increases in patients with preoperative empyema and postoperative BPF increases in right-side operation, the mortality rates and long-term survival rates were found to be satisfactory. However, the follow-up care for patients with low predicted postoperative FEV1 should continue for prevention and early detection of pulmonary complication related to impaired pulmonary function.

• Journal of Popular Narrative
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• v.26 no.3
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• pp.87-120
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• 2020

The study noted the characteristics of the web novel's 'Book Travel' motif, which reflects the characteristics of popular culture content, which is free to use familiar genre grammar or code. The imagination of the main character entering the work he read in the real world is a reinterpretation of the existing genre grammar of the web novel, and studying the motif is meaningful in reviewing the intertext of the genre. This motif, summarized as 'Book Travel' differs from other genres in the romance fantasy genre, which can also be used to reveal the gender characteristics of the genre. The study noted that the 'Book Travel' motif was born from an interactive interpretation of existing narratives, thus having a affinity with dimensional shift, regression, and alternative historical objects, and referring to the writing norms of Fanfiction. Through this, it was predicted that the re-combination of existing narratives and interference between genres would continue in the future. Next, the original move in the romance fantasy genre was seen as quite conservative and revealing the logic of self-improvement even though people around him became the main characters and overthrew the narrative. The characters should use their knowledge of the future of the real world to fight in a world of survival where destruction has been predicted. The appearance of an ethical and self-help subject is interesting, but on the other hand, I could look at conservatism in that romance is a way of survival and achievement of characters. The research is meaningful in that it reviewed the characteristics of the original transfer motif, which started fairly quickly in the romance fantasy genre, and reviewed its appearance background and characteristics. There was a limit to the collection of physical works and limited platform. The above limits are intended to be supplemented by further reviewing and supplementing later works.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.234-243
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• 2000

This paper is to study population ecological characteristics, including growth parameters, survival rate, instantaneous coefficients of natural and fishing mortalities, and age at first capture of the soft-shelled clam, Mya japonioa in the intertidal zone of South Sea in Korea. For describing growth of the clam a von Bertalanffy growth model was adopted, The von Bertalanffy growth curve had an additive error structure and the growth parameters estimated from a non-linear regression were SH/sub ∞/=79.83mm, K=0.26, and t/sub 0/= -0.01. Survival rate (S) of the soft-shelled clam was 0.26 (SD=0.02). The instantaneous coefficients of natural mortality (M) was estimated to be 0.78/year and fishing mortality (F) 0.57/year for the soft-shelled clam. The age at first capture (t/sub c/) was estimated as 2.69 year. The mean densities of the soft-shelled clam by bottom type were 3.40 inds./m²(SE=0.18) in the sand, 63.4 inds./m²(SE= 0.53) in the muddy sand, and 0 inds./m2 (SE=0) in the gravelly sand. The mean densities of the soft-shelled clam by 3 different areas were 4.88 inds./m²(SE=0.09), 2.61 inds./m²(SE=0.13), 7.20 inds./m²(SE=0.18), respectively and the biomass of the clam were estimated as 131mt, 121mt, 665mt, respectively. An yield-per-recruit analysis showed that the current yield-per-recruit of about 8.30g with F=0.57/year and the age at first capture (t/sub c/) 2.69 year, was lower than the maximum possible yield-per-recruit of 9.60g. Fixing to at the current level and increased fishing intensity (F) could produce an increase in the predicted yield-per-recruit from 8.30g to about 9.40. However, estimated yield-per-recruit increased to 1.30g by decreasing to from the current age (2.69 year) to age two with F fixed at the current level. Yield-per-recruit was estimated under harvest strategies based on F/sub max/ and F/sub 0.1/.

• Radiation Oncology Journal
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• v.30 no.2
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• pp.70-77
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• 2012

Purpose: To evaluate the patterns of tumor shape and to compare tumor volume derived from simple diameter-based ellipsoid measurement with that derived from tracing the entire tumor contour using region of interest (ROI)-based 3D volumetry with respect to the prediction outcome in cervical cancer patients treated with concurrent chemotherapy and radiotherapy. Materials and Methods: Magnetic resonance imaging was performed in 98 patients with cervical cancer (stage IB-IIIB). The tumor shape was classified into two categories: ellipsoid and non-ellipsoid shape. ROI-based volumetry was derived from each magnetic resonance slice on the work station. For the diameter-based surrogate "ellipsoid volume," the three orthogonal diameters were measured to calculate volume as an ellipsoid. Results: The more than half of tumor (55.1%) had a non-ellipsoid configuration. The predictions for outcome were consistent between two volume groups, with overall survival of 93.6% and 87.7% for small tumor (<20 mL), 62.9% and 69.1% for intermediate-size tumor (20-39 mL), and 14.5% and 16.7% for large tumors (${\geq}$40 mL) using ROI and diameter based measurement, respectively. Disease-free survival was 93.8% and 90.6% for small tumor, 54.3% and 62.7% for intermediate-size tumor, and 13.7% and 10.3% for large tumor using ROI and diameter based method, respectively. Differences in outcome between size groups were statistically significant, and the differences in outcome predicted by the tumor volume by two different methods. Conclusion: Our data suggested that large numbers of cervical cancers are not ellipsoid. However, simple diameter-based tumor volume measurement appears to be useful in comparison with ROI-based volumetry for predicting outcome in cervical cancer patients.