• Radiation Oncology Journal
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• v.28 no.4
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• pp.238-248
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• 2010

Purpose: To compare the dose distributions between three-dimensional (3D) and four-dimensional (4D) radiation treatment plans calculated by Ray-tracing or the Monte Carlo algorithm, and to highlight the difference of dose calculation between two algorithms for lung heterogeneity correction in lung cancers. Materials and Methods: Prospectively gated 4D CTs in seven patients were obtained with a Brilliance CT64-Channel scanner along with a respiratory bellows gating device. After 4D treatment planning with the Ray Tracing algorithm in Multiplan 3.5.1, a CyberKnife stereotactic radiotherapy planning system, 3D Ray Tracing, 3D and 4D Monte Carlo dose calculations were performed under the same beam conditions (same number, directions, monitor units of beams). The 3D plan was performed in a primary CT image setting corresponding to middle phase expiration (50%). Relative dose coverage, D95 of gross tumor volume and planning target volume, maximum doses of tumor, and the spinal cord were compared for each plan, taking into consideration the tumor location. Results: According to the Monte Carlo calculations, mean tumor volume coverage of the 4D plans was 4.4% higher than the 3D plans when tumors were located in the lower lobes of the lung, but were 4.6% lower when tumors were located in the upper lobes of the lung. Similarly, the D95 of 4D plans was 4.8% higher than 3D plans when tumors were located in the lower lobes of lung, but was 1.7% lower when tumors were located in the upper lobes of lung. This tendency was also observed at the maximum dose of the spinal cord. Lastly, a 30% reduction in the PTV volume coverage was observed for the Monte Carlo calculation compared with the Ray-tracing calculation. Conclusion: 3D and 4D robotic radiotherapy treatment plans for lung cancers were compared according to a dosimetric viewpoint for a tumor and the spinal cord. The difference of tumor dose distributions between 3D and 4D treatment plans was only significant when large tumor movement and deformation was suspected. Therefore, 4D treatment planning is only necessary for large tumor motion and deformation. However, a Monte Carlo calculation is always necessary, independent of tumor motion in the lung.

• Radiation Oncology Journal
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• v.26 no.4
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• pp.257-262
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• 2008

Purpose: Oral mucositis induced by radiotherapy to the head and neck area, is a common acute complication and is considered as the most severe symptom for cancer patients in the early stages of treatment. This study was proposed to establish the oral mucositis mouse model induced by a single dose of radiation for the facility of testing therapeutic candidates which can be used for the oral mucositis treatments. Materials and Methods: Fifty-five BALB/c mice were divided into four groups: control, 16 Gy, 18 Gy, and 20 Gy. Oral mucositis was induced by a single dose of radiation to the head and neck using 6 MV x-Ray from linear accelerator. After irradiation, body weight and physical abnormalities were checked daily. Tongue tissues from all groups were taken on days 1, 2, 3, 5, 7, 9, and 14, respectively and H&E staining was conducted to examine morphological changes. Results: Body weight dramatically decreased after day 5 in all irradiated mice. In the 16 Gy treatment group, body weight was recovered on day 14. The histology data showed that the thickness of the epithelial cell layer was decreased by the accumulated time after radiation treatment, up to day 9. Severe ulceration was revealed on day 9. Conclusion: A single dose of 16 Gy is sufficient dose to induce oral mucositis in Balb/C mice. Significant changes were observed in the Balb/C mice on days 7 and 9 after radiation. It is suggested that this mouse model might be a useful standard tool for studying oral mucositis induced by radiation.

• Journal of Genetic Medicine
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• v.8 no.1
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• pp.1-16
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• 2011

Owing to the risk of fetal loss associated with prenatal diagnostic procedures (amniocentesis, chorionic villus sampling), noninvasive prenatal diagnosis (NIPD) is ultimate goal of prenatal diagnosis. The discovery of circulating cell-free fetal DNA (cffDNA) in maternal plasma in 1997 has opened up new probabilities for NIPD by Dr. Lo et al. The last decade has seen great development in NIPD. Fetal sex and fetal RhD status determination by cffDNA analysis is already in clinical use in certain countries. For routine use, this test is limited by the amount of cell-free maternal DNA in blood sample, the lack of universal fetal markers, and appropriate reference materials. To improve the accuracy of detection of fetal specific sequences in maternal plasma, internal positive controls to confirm to presence of fetal DNA should be analyzed. We have developed strategies for noninvasive determination of fetal gender, and fetal RhD genotyping using cffDNA in maternal plasma, using real-time quantitative polymerase chain reaction (RT-PCR) including RASSF1A epigenetic fetal DNA marker (gender-independent) as internal positive controls, which is to be first successful study of this kind in Korea. In our study, accurate detection of fetal gender through gestational age, and fetal RhD genotyping in RhD-negative pregnant women was achieved. In this assay, we show that the assay is sensitive, easy, fast, and reliable. These developments improve the reliability of the applications of circulating fetal DNA when used in clinical practice to manage sex-linked disorders (e.g., hemophilia, Duchenne muscular dystrophy), congenital adrenal hyperplasia (CAH), RhD incompatibility, and the other noninvasive pregnant diagnostic tests on the coming soon. The study was the first successful case in Korea using cffDNA in maternal plasma, which has created a new avenue for clinical applications of NIPD.

• Journal of the Mineralogical Society of Korea
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• v.31 no.3
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• pp.161-172
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• 2018

Multi-anvil press (MAP) is one of the high pressure apparatuses and often generates the pressure-conditions ranging from 5 to 25 GPa and temperature-conditions up to $2,300^{\circ}C$. The MAP is, therefore, suitable to explore the pressure-induced structural changes in diverse earth materials from Earth's mantle and the bottom of the mantle transition zone (~660 km). In this study, we present the experimental results for pressure-load calibration of the 1,100-ton multi-anvil press equipped in the authors' laboratory. The pressure-load calibration experiments were performed for the 14/8 step, 14/8 G2, 14/8 HT, and 18/12 assembly sets. The high pressure experiments using ${\alpha}$-quartz, wollastonitestructure of $CaGeO_3$, and forsterite as starting materials were analyzed by powder X-ray diffraction spectroscopy. The phase transition of each mineral indicates the specific pressure that is loaded to a sample at $1,200^{\circ}C$: a transition of ${\alpha}$-quartz to coesite at 3.1 GPa, that of garnet-structure of $CaGeO_3$ to perovskite-structure at 5.9 GPa, that of coesite to stishovite at 9.2 GPa, and that of forsterite to wadsleyite at 13.6 GPa. While the estimated pressure-load calibration curve is generally consistent with those obtained in other laboratories, the deviation up to 50 tons is observed at high pressure above 10 GPa. This is partly because of the loss of oil pressure at high pressure resulting from the differences in a sample chamber, and the frictional force between pressure medium and second anvil. We also report the ${\sim}200^{\circ}C/mm$ of thermal gradient in the vertical direction of the sample chamber of 14/8 HT assembly. The pressure-load calibration curve and the observed thermal gradient within the sample chamber can be applied to explain the structural changes and the relevant macroscopic properties of diverse crystalline and amorphous earth materials in the mantle.

• Restorative Dentistry and Endodontics
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• v.31 no.6
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• pp.452-459
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• 2006

Competition will usually develop between the opposing walls as the restorative resin shrinks during polymerization. Magnitude of this phenomenon may be depended upon cavity configuration and volume. The purpose of this sturdy was to evaluate the effect of cavity configuration and volume on microleakage of composite resin restoration that has margins on the enamel site only. The labial enamel of forty bovine teeth was ground using a model trimmer to expose a flat enamel surface. Four groups with cylindrical cavities were defined, according to volume and configuration factor(Depth x Diameter / C-factor) - Group I : 1.5 mm ${\times}$ 2.0 mm / 4.0, Group II : 1.5 mm ${\times}$ 6.0 mm / 2.0, Group III : 2.Omm ${\times}$ 1.72 mm / 5.62, Group IV : 2.0 mm ${\times}$ 5.23 mm / 2.54. After treating with fifth-generation one-bottle adhesive - BC Plus$^{TM}$ (Vericom, AnYang, Korea), cavities were bulk flted with microhybrid composite resin - Denfill$^{TM}$ (Vericom). Teeth were stored in distilled water for one day at room temperature and were finished and polished with Sof-Lex system. Specimens were thermocycled 500 times between 5$^{\circ}$C and 55$^{\circ}$C for 30 second at each temperature. Teeth were isolated with two layers of nail varnish except the restoration surface and 1 mm surrounding margins. Electrical conductivity (${\mu}$A) was recorded in distilled water by electrochemical method. Microleakage scores were compared and analyzed using two-way ANOVA at 95% level. The results were as follows: 1. Small cavity volume showed lower microleakage score than large one, however, there was no statistically significant difference. 2. There was no relationship between cavity configuration and microleakage. Factors of cavity configuration and volume did not affect on microleakage of resin restorations with enamel margins only.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.80-80
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• 2003

${\beta}$-lapachone(${\beta}$-Lap), a natural o-naphthoquinone, presents in the bark of the Lapacho tree. ${\beta}$-Lap is cytotoxic against a variety of human cancer cells and it potentiates the anti-tumor effect of Taxol. In addition, ${\beta}$-Lap has been reported to radiosensitize cancer cells by inhibiting the repair of radiation-induced DNA damage.In the present study, we investigated the cytotoxicity of ${\beta}$-Lap against RKO human colorectal cancer cells as well as the combined effect of ${\beta}$-LaP and ionizing radiation. An incubation of RKO cells with 5 ${\mu}$M of ${\beta}$-Lap for 4 h killed almost 90％ of the clonogenic cells. An incubation of RKO cells with 5 ${\mu}$M of ${\beta}$-Lap for 4 h or longer also caused massive apoptosis. Unlike other cytotoxic agents, ${\beta}$-Lap did not increase the expression of p53 and p21 and it suppressed the NFkB expression. The expression of Caspase 9 and 3 was minimally altered by ${\beta}$-Lap. Radiation and ${\beta}$-Lap acted synergistically in inducing clonogenic cell death and apoptosis in RKO cells when ${\beta}$-Lap treatment was applied after but not before the radiation exposure of the cells. Interestingly, a 4 h treatment with 5 ${\mu}$M of ${\beta}$-Lap starting 5 h after irradiation was as effective as that starting immediately after irradiation. The mechanisms of ${\beta}$-Lap-induced cell killing is controversial but a recent hypothesis is that ${\beta}$-Lap is activated by NAD(P)H: quinone-onidoreductase (NQO1) in the cells followed by an elevation of cytosolic Ca$\^$2+/ level and activation of proteases leading to apoptosis. It has been reported that NQO1 level in cells is markedly up-regulated for longer than 10 h after irradiation. Indeed, using immunological staining of NQO1, we observed a significant elevation of NQO1 expression in RKO cells 5h after 2-4 Gy irradiation. Such a prolonged elevation of NQO1 level after irradiation may be the reasons why the ${\beta}$-Lap treatment applied S h after irradiation was as effective as that applied immediately after irradiation in killing the cells. In view of the fact that the repair of radiation-induced damage is usually completed within 1-2 h after irradiation, it is highly likely that the ${\beta}$-Lap treahment applied 5 h after irradiation could not inhibit the repair of radiation-induced damage. For in vivo study, RKO cells were injected S.C. into the hind-leg of Nu/Nu mice, and allowed to grow to 130 mm3 tumor. The mice were i.p. injected with ${\beta}$-lapachone or saline 2 h after irradiation of tumors with 10 Gy of X-rays. The radiation induced growth delay was increased by 2.4 $\mu\textrm{g}$/g of ${\beta}$-lapachone. Taken together, we may conclude that the synergistic interaction of radiation and ${\beta}$-Lap in killing cancer cells is not due to radiosensitization by ${\beta}$-Lap but to an enhancement of ${\beta}$-Lap cytotoxicity by radiation through an upregulation of NQO1. The fact that NQO1 is elevated in tumors and that radiation causes prolonged increase of the NQO1 expression may be exploited to preferentially kill tumor cells using ${\beta}$-Lap in combination with radiotherapy.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.2 no.1
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• pp.67-85
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• 1995

The purpose of this study was to determine the effects of rhythmic movement therapy for adaptation state in mastectomy patients. The quasi-experimental study was designed using nonequivalent control group pretest-posttest design within the framework of Laszarus & Folkman's stress-adaptation model. The subjects of the study were composed thirty-two mastectomy patients, of these fifteen were assigned to the experimental group and seventeen to the control group. Rhythmic movement therapy was carried out twice a week for thirty-five, minutes or forty minutes for six weeks period from August 22 to September 30 in 1994. Data was collected before and after the experimentation. Collected data was analyzed by mens of chi-square test, t-test, two-way ANOVA, Pearson's correlation coefficient with $SPSS/PC^+$. The results were summarized as follows : 1. Physical symptom score in the experimental group and control group was not significant difference. 2. Joint Movement Parameter in the experimental group and control group was significant difference. 3. Depression score in the experimental group and contrl group was significant difference. 4. Body image score in the experimental group and control group was significant difference. 5. Stress perception score in the experimental group and control group was significant difference. 6. Social adjustment score in the experimental group and control group was significant difference. 7. Each adaptational level in the experimental group and control group according to type of Health Locus of Control were partially significant difference. Depression score and social adjustment score between the experimental group and control group according to others Health Locus of control were significant difference. This data suggest that rhythmic movement therapy was more effective in the group of Others health Locus of Control. 8. Each adaptational level between the experimental group and control group according to amount of spouse support were not significant difference. 9. The significant positive correlation between physical symptom score and body image, between body image and social adjustment, were observed. The significant negative correlation between stress perception score and social adjustment, between depression and body image, between depression and social adjustment, were observed. This data suggest that the more physical symptom score increased, the more body image increased and the more body image, the more social adjustment. And then the more stress perception score decreased, the more social adjustment increasded and the more depression score, the more body image and social adjustment. Thus it is concluded that the rhythmic movement therapy was a useful nursing intervention for adaptation of mastectomy patients.

• Tuberculosis and Respiratory Diseases
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• v.44 no.2
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• pp.401-408
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• 1997

Background : Pulmonary sequestration is a rare congenital malformation, which is manifested by formation of nonfunctioning lung tissue lacking normal communication with the tracheobronchial tree. The preoperative diagnostic rate has been relatively low, and without consideration of pulmonary sequestration, unexpected bleeding from aberrant vessels may be a serious problem during the operation. The purpose of our study is to describe the clinical features of pulmonary sequestration based on a review of 15 cases treated by operation. Method : Fifteen patients with pulmonary sequestration who had undergone surgical treatment from 1991 through May 1996 at Yongdong Severance Hospital and Severance Hospital were reviewed retrospectively. Results : The mean age of the patients was 22.5 years (range 5~57), and male to female ratio was 9 : 6. Clinical presentations varied from recurrent respiratory infections such as fever, cough, and sputum or chest pain to no symptom. The chest simple X-rays showed multicystic shadow(10/15) and solid mass-like shadow(5/15). The chest CT scans, done in twelve cases, showed multicystic lesion with or without lung infiltration(8/12), solid mass-like lesion(4/12), The chest MRIs, done in three cases, revealed the aberrant arteries originating from descending aorta(2/3). Aortograms, done in four cases, showed the aberrant arteries originating from descending thoracic aorta(2/4), abdominal aorta(I/4), and intercostal artery(1/4). and the venous returns were via the pulmonary veins. Pulmonary sequestration was considered preoperatively in six patients of fifteen. Other preliminary diagnosis were lung tumor(3/15), lung abscess(21/15), bronchiectasis(2/15), and mediastinal tumor(2/15). In the operative findings, twelve cases were of intralobar type and three cases of extralobar type. The left lower lobe was most often affected(9/15) and one extralobar sequestration was in the pericardium. The aberrant arteries originated from descending thoracic aorta(6/15), abdominal aorta(1/15), internal thoracic arteries (2/15), intercostal artery(1/15), pericardiophrenic artery(1/15), but in four cases, the origins could not be defined. There was no mortality or complication postoperatively. Conclusion : In our study, preoperative diagnostic rate was relatively low, and clinical features were similar to previous reports. Preoperative vigorous diagnostic approach including aortography is strongly advocated not only for its diagnostic value, but also for accurate localization of the aberrant vessels, which is major concern to surgical procedure.

• Tuberculosis and Respiratory Diseases
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• v.49 no.5
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• pp.614-623
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• 2000

Background : Diffuse alveolar hemorrhage (DAH) is rare but often fatal. To determine the clinical manifestations of DAH, its etiology, clinical course and prognosis were studied. Method : A retrospective analysis was performed in 21 patients that were diagnosed as DAH. Diagnosis of DAH was based on the presence of the "classical triad" of hemoptysis, anemia, and rapidly progressive infiltrates on chest X-ray and a finding of bronchoalveolar lavage or lung biopsy. Results : Thirteen patients (61.9%) had collagen vascular diseases (CVDs) as underlying disease and 10 patients had systemic lupus erythematosus. Females were more prevalent in CVD than in non-collagen vascular disease (NCVD). Otherwise, there were no significant differences between the two groups in terms of clinical manifestations. Dyspnea (95.2%), cough (76.2%), hemoptysis (61.9%), and fever (33.0%) were frequent symptoms. The initial creatinine level was higher in CVD than in NCVD ($3.27{\pm}3.15$ mg/dl vs. $1.19{\pm}0.94$ mg/dl, p=0.030). The corresponding drop in hemoglobin level was $2.69{\pm}1.26$ g/dl. Maximal drop in hemoglobin preceded the progression of infiltrates on the chest radiograph by $1.38{\pm}4.22$ days. The mortality rate was higher in the patients with NCVD than in those with CVD (50.0% vs. 23.1%). Conclusion : The DAH can occur not only in patients with CVD but also in those with NCVD. Higher creatinine level CVD in patients is associated with renal involvement in conjunction with DAH. The maximal drop in hemoglobin preceeding the progression of infiltrates on the chest radiograph suggests that the drop in hemoglobin is important for diagnosing DAH.

• Tuberculosis and Respiratory Diseases
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• v.72 no.1
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• pp.8-14
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• 2012

Background: Although airway obstruction in chronic obstructive pulmonary disease (COPD) is due to pathologic processes in both the airways and the lung parenchyma, the contribution of these processes, as well as other factors, have not yet been evaluated quantitatively. We therefore quantitatively evaluated the factors contributing to airflow limitation in patients with COPD. Methods: The 213 COPD patients were aged >45 years, had smoked >10 pack-years of cigarettes, and had a post-bronchodilator forced expiratory volume in one second ($FEV_1$)/forced vital capacity (FVC) <0.7. All patients were evaluated by medical interviews, physical examination, spirometry, bronchodilator reversibility tests, lung volume, and 6-minute walk tests. In addition, volumetric computed tomography (CT) was performed to evaluate airway wall thickness, emphysema severity, and mean lung density ratio at full expiration and inspiration. Multiple linear regression analysis was performed to identify the variables independently associated with $FEV_1$ - the index of the severity of airflow limitation. Results: Multiple linear regression analysis showed that CT measurements of mean lung density ratio (standardized coefficient ${\beta}$=-0.46; p<0.001), emphysema severity (volume fraction of the lung less than -950 HU at full inspiration; ${\beta}$=-0.24; p<0.001), and airway wall thickness (mean wall area %; ${\beta}$=-0.19, p=0.001), as well as current smoking status (${\beta}$=-0.14; p=0.009) were independent contributors to $FEV_1$. Conclusion: Mean lung density ratio, emphysema severity, and airway wall thickness evaluated by volumetric CT and smoking status could independently contribute to the severity of airflow limitation in patients with COPD.