• Journal of Radiation Protection and Research
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• v.33 no.4
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• pp.127-134
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• 2008

Potential economic impact of a hypothetical severe accident at a nuclear power plant(Uljin units 3/4) was estimated by applying the Delphi method, which is based on the expert judgements and opinions, in the process of quantifying uncertain factors. For the purpose of this study, it is assumed that the radioactive plume directs the inland direction. Since the economic risk can be divided into direct costs and indirect effects and more uncertainties are involved in the latter, the direct costs were estimated first and the indirect effects were then estimated by applying a weighting factor to the direct cost. The Delphi method however subjects to risk of distortion or discrimination of variables because of the human behavior pattern. A mathematical approach based on the Bayesian inferences was employed for data processing to improve the Delphi results. For this task, a model for data processing was developed. One-dimensional Monte Carlo Analysis was applied to get a distribution of values of the weighting factor. The mean and median values of the weighting factor for the indirect effects appeared to be 2.59 and 2.08, respectively. These values are higher than the value suggested by OECD/NEA, 1.25. Some factors such as small territory and public attitude sensitive to radiation could affect the judgement of panel. Then the parameters of the model for estimating the direct costs were classified as U- and V-types, and two-dimensional Monte Carlo analysis was applied to quantify the overall economic risk. The resulting median of the overall economic risk was about 3.9% of the gross domestic products(GDP) of Korea in 2006. When the cost of electricity loss, the highest direct cost, was not taken into account, the overall economic risk was reduced to 2.2% of GDP. This assessment can be used as a reference for justifying the radiological emergency planning and preparedness.

• Radiation Oncology Journal
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• v.21 no.3
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• pp.227-237
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• 2003

Purpose: The human chronic myelogenous leukemia cell line, K562, expresses the chimeric bcr-abl oncoprotein, whose deregulated protein tyrosine kinase activity antagonizes via DNA damaging agents. Previous experiments have shown that nanomolar concentrations of herbimycin A (HWA) coupled with X-irradiation have a synergistic effect in inducing apoptosis in the Ph-positive K562 leukemia cell line, but genistein, a PTK inhibitor, is non selective for the radiation-induced apoptosils on $p210^{bcr/abl}$ protected K562 cells. In these experiments, the cytoplasmic signal transduction pathways, the Induction on a number of transcription factors and the differential gene expression in this model were investigated. Materials and Methids: K562 cells in the exponential growth phase were used in this study. The cells were irradiated with 0.5-12 Gy, using a 6 Mev Linac (Clinac 1800, Varian, USA). Immediately after irradiation, the cells were treated with $0.25/muM$ of HMA and $25/muM$ of genistein, and the expressions and the activities of abl kinase, MAPK family, NF- kB, c-fos, c-myc, and thymidine kinase1 (TK1) were examined. The differential gene expressions induced by PTK inhibitors were also investigated. Results: The modulating effects of herbimycin A and genistein on the radiosensitivity of K562 cells were not related to the bcr-abl kinase activity. The signaling responses through the MAPK family of proteins, were not involved either in association with the radiation-induced apoptosis, which is accelerated by HMA, the expression of c-myc was increased. The combined treatment of genistein, with irradiation, enhanced NF- kB activity and the TK1 expression and activity. Conclusion: The effects of HMA and genistein on the radiosensitivity on the K562 cells were not related to the bcr-abl kinase activity in this study, another signaling pathway, besides the WAPK family responses to radiation to K562 cells, was found. Further evaluation using this model will provide valuable information for the optional radiosensitization or radioprotection.

• Radiation Oncology Journal
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• v.21 no.4
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• pp.306-314
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• 2003

Purpose : In our Previous study, we have shown the main cel1 death pattern Induced by irradiation or protein tyrosine kinase (PTK) inhibitors in K562 human myeiogenous leukemic cell line. Death of the cells treated with irradiation alone was characterized by mitotic catastrophe and typical radiation-induced apoptosis was accelerated by herblmycin A (HMA). Both types of cell death were inhibited by genistein. In this study, we investigated the effects of HMA and genistein on cell cycle regulation and its correlation with the alterations of radiation-induced cell death. Materials and Methods: K562 cells In exponential growth phase were used for this study. The cells were Irradiated with 10 Gy using 6 MeV Linac (200-300 cGy/min). Immediately after irradiation, cells were treated with 250 nM of HMA or 25 $\mu$N of genistein. The distributions of cell cycle, the expressions of cell cycle-related protein, the activities of cyclin-dependent kinase, and the yield of senescence and differentiation were analyzed. Results: X-irradiated cells were arrested In the G2 phase of the cell cycle but unlike the p53-positive cells, they were not able to sustain the cell cycle arrest. An accumulation of cells in G2 phase of first ceil-cycle post-treatment and an increase of cyclin Bl were correlated with spontaneous, premature, chromosome condensation and mitotic catastrophe. HMA induced rapid G2 checkpoint abrogation and concomitant p53-independent Gl accumulation. HMA-induced cell cycle modifications correlated with the increase of CDK2 kinase activity, the decrease of the expressions of cyclins I and A and of CDK2 kinase activity, and the enhancement of radiation-induced apoptosis. Genistein maintained cells that were arrested in the G2-phase, decreased the expressions of cyclin Bl and cdc25c and cdc25C kinase activity, increased the expression of pl6, and sustained senescence and megakaryocytic differentiation. Conclusion: The effects of HMA and genistein on the radiation-induced cell death of KS62 cells were closely related to the cell cycle regulatory activities. In this study, we present a unique and reproducible model in which for investigating the mechanisms of various, radiation-induced, cancer cell death patterns. Further evaluation by using this model will provide a potent target for a new strategy of radiotherapy.

• Journal of The Korean Society of Clinical Toxicology
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• v.3 no.2
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• pp.79-85
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• 2005

Purpose: With the recent boom in 'eating healthy', many adults are interested in dieting to prevent future diseases. However only well trained experts can distinguish between what are edible vegetables and herbs from their poisonous look-alikes. In cases where a patient unknowingly ingests a poisonous herb, is caught off guard by the poisonous side effects that occur because of their lack of knowledge of what they have ingested. This paper will focus on the need to educate the public about the risks involved with ingesting wild vegetables and herbs and study the emergency diagnosis and treatment of poisoned patients that enter the emergency room. Method: This study was done in the spring of 2004 (from March to May) in the Kangwon Young-Seo districts of Korea. 15 subjects used in this study, entered the emergency room showing signs of toxic symptoms. Data was collected by examining subject's records. Additional data was collected by collaborating with physicians in the hospital that diagnosed and treated the subjects. Identifying the poisonous vegetable or herb is the first step to proper diagnosis and treatment. Subjects admitted to the emergency room, underwent a battery of tests: laboratory examination, ECG, radiological exam and etc. Results: The demographics of the study encompassed subjects with the average age of $50{\pm}19$ years old. There were 10 men and 5 women. Common symptoms of this study included; gastrointestinal symptoms such as nausea, vomiting, epigastric pain and so on. In the case of Caltha palustris ingestion, additional symptoms were present; bradycardia and hypotension which lasted for a long time. While cases that ingested Scopolia parviflora had little effect on vital signs but manic episodes lasted for about three days. Veratrum patulum ingestion showed signs of bradycardia and hypotension but contrary to Caltha palustris recovery was shorten by treating with dopamine. However, dizziness, headache and paresthesia of the extremities continued for a long time. Finally Sium ninsi ingestion showed visual disturbance, paresthesia of the extremities, dizziness as their initial symptoms. Conclusion: The risks involved with ingesting wild plants without the proper knowledge can lead to serious side effects and steps need to be taken to educate the public. In addition, all emergency physicians need to have a working knowledge of the symptoms and signs associated with ingesting toxic wild plants and need to treat accordingly.

• Clinical and Experimental Pediatrics
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• v.52 no.4
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• pp.429-434
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• 2009

Purpose : Severe aspiration of the amniotic fluid is known to cause fatal respiratory distress in neonates. We conducted this study to investigate the clinical findings of severe amniotic fluid aspiration pneumonia (AFAP) in neonates and the effect of pulmonary surfactant replacement therapy (SRT). Methods : Retrospective analysis of medical records was conducted on 28 patients who received ventilator care due to severe AFAP in a neonatal intensive care unit over a 7-year period (2000-2006). Patients whose amniotic fluid was contaminated with meconium were excluded. Results : A large number of cases were term infants (82.1%) and infants born by caesarean section (85.7%), and the 1- and 5-min Apgar scores of these patients were $6.5{\pm}1.2$ and $7.5{\pm}1.3$, respectively. Soon after birth, the amount of amniotic fluid sucked out from airway below the vocal cord was $16.0{\pm}10.1$ mL. All patients received SRT with a modified bovine-derived surfactant (120 mg/kg/dose), and one dose was administered in most cases (75%). Compared with pre-SRT, the oxygenation index ($8.0{\pm}9.6$ vs. $18.9{\pm}7.3$) according to ventilator care was a significant improvement at 12 h after SRT (P<0.001). Furthermore, most cases showed radiological improvement for aeration at 12 h post-treatment. Many cases (46.4%) had cardiorespiratory complications, but their final outcomes were excellent (survival rate, 96.4%). Conclusion : AFAP may be an important cause of serious respiratory distress in near-term and term infants, and SRT seems to be an effective adjuvant therapy in mechanically ventilated neonates with severe AFAP.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.138-144
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• 2010

Purpose: Despite the rapidly changing healthcare environment, healthcare organizations have recognized the importance of patient safety management. But patient safety management has the problem of the lack of participation of members due to the process of focusing on the follow-up service and punishment. The department of nuclear medicine in Uijeongbu St. Mary's Hospital started this research to reduce the near miss and prevent patient safety accidents by both initiating the participatory near-miss-proof activities as an advance management and constructing a system without disadvantages of reporting. In addition, this research aims to establish a differentiated patient safety management system in the department of nuclear medicine. Materials and Methods: 1. Colleting cases of team members' past and present near miss and accidents(First data collection). 2. Quantifying the cases of near miss and accidents after identifying the degree of importance and urgency through surveys(Second data collection). 3. Quantifying cases and indentifying important points of contact through data analysis. 4. Making and standardizing a manual for important points of contact, and initiating participatory activities to prevent errors. 5. Activating web-based community for establishing the report system of near miss. 6. Estimating the result of before and after activities through surveys and focus group interviews. Results: 1) Quantified safety accidents and near miss in the department of nuclear medicine. About 50 near misses a month and one safety accident a year. 2) Establishing improvement measurements based on quantified data. About 11 participatory activities, the improvement of process, a manual for standardization. 3) Creating a system of safety culture and high participation rate of team members. Constructing a report system, making a check list and a slogan for safety culture, and establishing assessment index. 4) Activating communities for sharing the information of cases of near misses and accidents. 5) As the result of activities, the rate of near miss occurrence declined by 50% and the safety accident did not happen. Conclusion: The best service in the department of nuclear medicine is to provide patients with safety-guaranteed high-quality examination and cure. This research started from the question, 'what is the most faithful-to-the-basics way to provide the best service for patients?' and team members' common answer for this question was building a system with participation of all members. Building a system through the participatory improvement activities for preventing near miss and creating safety culture resulted in the 50% decline of near miss occurrence and no accident. This is a meaningful result from the perspective of advance management for patient safety. Moreover, this research paved the way for creating a culture to report and admit near miss or accidents by establishing a report system with no disadvantage of reporting. The system which sticks to the basics is the best service for patients and will form a patient safety culture system, which will lead to the customer satisfaction. Therefore, all members of the department of nuclear medicine will develop a differentiated patient safety culture with stabilizing the established system.

• Journal of Environmental Health Sciences
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• v.37 no.2
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• pp.102-112
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• 2011

Objectives: The purpose of this study is to analyze the effects of chronic exposure by welders to manganese (Mn) through an analysis of the degree of brain activity in different activities such as cognition and motor activities using the neuroimaging technique of functional magnetic resonance imaging (fMRI). The neurotoxic effect that Mn has on the brain was examined as well as changes in the neuro-network in motor areas, and the usefulness of fMRI was evaluated as a tool to determine changes in brain function from occupational exposure to Mn. Methods: A survey was carried out from July 2010 to October 2010 targeting by means of a questionnaire 160 workers from the shipbuilding and other manufacturing industries. Among them, 14 welders with more than ten years of job-related exposure to Mn were recruited on a voluntary basis as an exposure group, and 13 workers from other manufacturing industries with corresponding gender and age were recruited as a control group. A questionnaire survey, a blood test, and an fMRI test were carried out with the study group as target. Results: Of 27 fMRI targets, blood Mn concentration of the exposure group was significantly higher than that of the control group (p<0.001), and Pallidal Index (PI) of the welder group was also significantly higher than that of the control group (p<0.001). As a result of the survey, the score of the exposure group in self-awareness of abnormal nerve symptoms and abnormal musculoskeletal symptoms was higher than those of the control group, and there was a significant difference between the two groups (p<0.05, respectively). In the correlation between PI and the results of blood tests, the correlation coefficient with blood Mn concentration was 0.893, revealing a significant amount of correlation (p<0.001). As for brain activity area within the control group, the right and the left areas of the superior frontal cortex showed significant activity, and the right area of superior parietal cortex, the left area of occipital cortex and cerebellum showed significant activity. Unlike the control group, the exposure group showed significant activity selectively on the right area of premotor cortex, at the center of supplementary motor area, and on the left side of superior temporal cortex. In the comparison of brain activity areas between the two groups, the exposure group showed a significantly higher activation state than did the control group in such areas as the right and the left superior parietal cortex, superior temporal cortex, and cerebellum including superior frontal cortex and the right area of premotor cortex. However, in nowhere did the control group show a more activated area than did the exposure group. Conclusions: Chronic exposure to Mn increased brain activity during implementation of hand motor tasks. In an identical task, activation increased in the premotor cortex, superior temporal cortex, and supplementary motor area. It was also discovered that brain activity increase in the frontal area and occipital area was more pronounced in the exposure group than in the control group. This result suggests that chronic exposure to Mn in the work environment affects brain activation neuro-networks.

• Tuberculosis and Respiratory Diseases
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• v.55 no.2
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• pp.175-187
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• 2003

Background : Although corticosteroid and cytotoxic agent such as cyclophosphamide have been used for the treatment idiopathic interstitial pneumonia (IIP), efficacy of these toxic drugs are unclear because previous reports included the patients who did not undergo surgical lung biopsy and none evaluated the response according to histopathologic entities of IIP. To answer this, we retrospectively analyzed the treatment response and side effects of corticosteroids and cyclophosphamide therapy in patients with idiopathic UIP and NSIP. Methods : Among 61 patients with UIP and 26 patients with NSIP diagnosed by surgical lung biopsy at Samsung Medical Center from July 1996 to June 2002, those who received corticosteroid or cyclophosphamide therapy for at least 6 months and were followed for at least one year after the initiation of treatment were enrolled (32 UIP, 23 NSIP). Treatment response of 55 patients was assessed by ATS response criteria (clinical symptoms, pulmonary function test and radiological findings). Adverse reactions to either agent (42 cases of cyclophosphamide${\pm}$low-dose prednisolone, 49 cases of prednisolone alone) were also analyzed. Results : Irrespective of treatment regimen, NSIP showed more favorable response than UIP (6 months: 78.3% vs. 9.4%, 12 months: 69.6% vs. 9.4%, p<0.001). Cyclophosphamide showed comparable response to corticosteroid in NSIP while its efficacy was as poor as those of corticosteroid therapy in UIP. Significant adverse reaction to drug more frequently occurred in corticosteroid group (35.7%) than cyclophosphamide group (14.3%) (p=0.017). Conclusion : Cyclophosphamide is effective and more tolerable than corticosteroids in the treatment of idiopathic nonspecific interstitial pneumonia.

• Tuberculosis and Respiratory Diseases
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• v.46 no.2
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• pp.165-174
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• 1999

Background: Coal-worker's pneumoconiosis(CWP) is radiologically divided into two major groups: simple pneumoconiosis (SP), in which small, rounded or irregular opacities smaller than 1cm are observed, and progressive massive fibrosis(PMF), which is characterized by opacities larger than 1cm. SP has a life expectancy equivalent to miners with no radiographic evidence of CWP, but PMF is associated with more obvious impairments of ventilatory capacity and premature death. But only minority of workers develop PMF when exposed to dust concentrations similar to those experienced by workers who develop only SP. In this study, immune status in patients with CWP were evaluated by measurement of the serum immunoglobulin levels between control, SP and PMF groups. Method: Coal workers selected for this study were emplyees of the Tae-Baek and Dong-Hae Hospital. All the patients were men of 45-76 years old and the mean duration of exposure to coal dust were 23.2 years. By X-ray examination, 51 patients were classified in SP, 59 in PMF category. The normal controls examined were 58 men of 26-70 years old. Serum Ig levels were estimated by using Nephelometer(Behring Nephelometer : Germany) and serum were collected 51 in SP, 49 in PMF and 57 cases in control group. Results: The levels of IgG were increased but the levels of IgM were decreased with increasing age in control groups. There were no statistical difference of immunoglobulin levels between smokers and nonsmokers in control groups. There were no statistical difference of immunoglobulin levels between Control, SP and PMF groups. Multiple regression analysis were undertaken to determine the statistical significance of the apparent trends and estimate the effects associated with age, smoking habit and radiological category of CWP. According to this analysis, the levels of IgG were decreased significantly in SP group and had decreasing tendancy, but not statistically significant in PMF group. Conclusion : From the observations described, CWP patients had decreased IgG concentration compared to control gorup. Therefore, there was some relation between CWP and immunoglobulin concentration.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.53-61
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• 2013

Objectives: It is certain that Radioactive iodine thyroid uptake(RAIU) rate should be measured with the standard counts considering the thyroid gland depth in enlarged thyroid patients for the variation from geometric factors. The purpose of this paper is to consider the effects of geometric factors according to detector to source distance and the effective thyroid depth on RAIU rate with experiment test. Materials and Methods: I-131 370 kBq ($10{\mu}Ci$) point source was measured by Captus-3000 thyroid uptake system (Capintec, NJ, USA) with a change Detector-Source Distance from 20 cm to 30 cm at an interval of 1 cm. And we changed the Neck phantom surface-Source Depth in the phantom with 1 cm, 2 cm, 5 cm using the neck phantom in order to reproduce the effective thyroid depth. Results: Every experimental group follows power curve as inverse square curve ($$R2{\geq_-}0.915$$). The average count rates in the case not using a phantom and the every case applied the effective thyroid depth using a phantom was not identical each other. There was significant fluctuations upon the effective thyroid depths applied the effective thyroid depth above 1 cm in $364.4 keV{\pm}10%$ energy ROI (p<0.01). There was not significant difference between the count rates of 1 cm and 2 cm in $364.4keV{\pm}20%$ and $637.1keV{\pm}6.2%$ (p=0.354, p=0.397). In assumed RAIU rate from regression equation, $364.4keV{\pm}20%$ was lower difference than $364.4keV{\pm}10%$ as 6.42% and 5.09% per 1 cm. Every change of count rate upon depth appears decreased line on Linear Regression, but the case of $284.3keV{\pm}10%$ increased only. And also, The graphs of coefficient of variation upon depth increased as straight line on every experimental group. Conclusion: The result appears that application of $364.4keV{\pm}20%$ energy ROI is more suitable for reducing error from the effective thyroid depth. And also, we can estimate the error of 20 cm should be highly reduced than 30 cm for Inverse Square Law. Therefore, If there is not information of the thyroid depth, it is considered that the error from thyroid depth can reduce through set up energy ROIs for $364.4keV{\pm}20%$, and increase Detector-Source Distances.