• The Korean Journal of Nuclear Medicine
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• v.28 no.2
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• pp.177-185
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• 1994

Pharmacologic coronary vasodilation in conjunction with myocardial perfusion scintigraphy has become an alternative to dynamic exercise test for the diagnosis and risk stratification of coronary artery disease, especially in patients who are unable to perform adequate exercise. Dipyridamole and adenosine have been used for pharmacologic stress testing with myocardial perfusion imaging. Adenosine is a potent coronary vasodilator with rapid onset of action, short half-life, near maximal coronary vasodilation and less serious side effects. ST segment depression has been reported in about 7-15% of patients with coronary artery disease receiving dipyridamole in conjunction with myocardial perfusion imaging. The exact cause and clinical significance are not known. In order to evaluate the relationship between adenosine-induced ST segment depression during $^{99m}Tc$-MIBI myocardial perfusion scintigraphy and the severity of coronary artery disease, we performed $^{99m}Tc$-MIBI imaging after intravenous Infusion of adenosine In 120 patients with suspected coronary artery disease. Of the 120 patients, 28 also performed coronary angiography. There were 24 patients with ST segment depression during $^{99m}Tc$-MIBI scintigraphy and 96 patients without ST segment depression. Adenosine was infused Intravenously at a dose of 0.14mg/kg per minute lot 6minutes and $^{99m}Tc$-MIBI was injected at 3 minute. We then com-pared the hemodynamic changes, side effects, scintigraphic and angiographic findings. Heart rate increased $90{\pm}19$ beats/minute in the group with ST depression compared with $80{\pm}16$ beats/minute in the group without ST depression(p<0.05). Baseline systolic blood pressure was significantly higher in the group with ST depression($152{\pm}27$ mmHg) than in the group without 57 depression($140{\pm}21$mmHg, p<0.05). Double product at baseline($10.90{\pm}2.77$ versus $9.55{\pm}2.34\;beats/minute{\times}mmHg$) and during adenosine infusion($12.72{\pm}3.89$ versus $10.83{\pm}2.98\;beats/minute{\times}mmHg$) were significantly higher in the group with ST depression(p<0.05). The incidence of anginal chest pain was also significantly higher in the group with ST depression(ST versus 29%, p<0.0001). The $^{99m}Tc$-MIBI images were abnormal in 23(96%) patients with ST segment depression and 66(69%) patients without ST segment depression(p<0.05). In patients with ST segment depression, there were more reversible perfusion defects than in patients without ST segment depression(83 versus 55%, p<0.05). The number of abnormal segments were significantly higher in the group with ST depression($3.05{\pm}2.01$ versus $1.51{\pm}1.45$, p<0.005). In patients with ST segment depression, there were more segments of reversible perfusion defects than in patients without segment depression($2.15{\pm}2.11$ versus $0.89{\pm}1.24$, p<0.05). There were no differences in the angiographic severity by vessel(p ; NS). We concluded that ST segment depression during $^{99m}Tc$-MIBI myocardial perfusion scintigraphy with Intravenous adenosine is related to the severity of coronary artery disease.

• Journal of Life Science
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• v.23 no.8
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• pp.989-997
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• 2013

In this study, based on the antioxidative effects in organic solvent fractions obtained from the main methanolic extract of L. japonica, the protective cellular effects and gene expression patterns of ethyl acetate fractions on $H_2O_2$-induced Raw 264.7 cell death ($IC_{50}$) were analyzed. The antioxidant activity of the fractions measured using DPPH free radical scavenging activity increased in a dose-dependent manner, and the $ED_{50}$ exhibited the highest $39.56{\mu}g/ml$ in the ethyl acetate fraction. In addition, the ethyl acetate fractions' cell viability on $H_2O_2$-induced Raw 264.7 cell damage increased in a concentration-dependent manner, showed a visible cell survival rate of 82.49% at a concentration of $100{\mu}g/ml$. The gene expression patterns related to the ethyl acetate fractions' cytoprotective effect in $H_2O_2$-induced Raw 264.7 cell damage presented similar patterns to those of BHA. In comparative analysis for antioxidant activity-related genes affected by ethyl acetate fractions and BHA in $H_2O_2$-induced Raw 264.7 cells, both ethyl acetate fractions and BHA showed very similar gene expression patterns, but the gene expression level of the heme oxygenase 1 (Hmox1) gene making antioxidant enzymes in cells was four times higher in ethyl acetate fractions than BHA. In inflammation-related genes in $H_2O_2$induced Raw 264.7 cells, the T-box transcription factor (Tbx21) gene was expressed about two times more frequently in the ethyl acetate fraction treatment group, while it was expressed half as frequently in the BHA treatment group.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.343-356
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• 2016

The Korea Radioactive Waste Agency (KORAD) has developed a dual-purpose metal cask for the dry storage of spent nuclear fuel that has been generated by domestic light-water reactors. The metal cask was designed in compliance with international and domestic technology standards, and safety was the most important consideration in developing the design. It was designed to maintain its integrity for 50 years in terms of major safety factors. The metal cask ensures the minimization of waste generated by maintenance activities during the storage period as well as the safe management of the waste. An activation evaluation of the main body, which includes internal and external components of metal casks whose design lifetime has expired, provides quantitative data on their radioactive inventory. The radioactive inventory of the main body and the components of the metal cask were calculated by applying the MCNP5 ORIGEN-2 evaluation system and by considering each component's chemical composition, neutron flux distribution, and reaction rate, as well as the duration of neutron irradiation during the storage period. The evaluation results revealed that 10 years after the end of the cask's design life, $^{60}Co$ had greater radioactivity than other nuclides among the metal materials. In the case of the neutron shield, nuclides that emit high-energy gamma rays such as $^{28}Al$ and $^{24}Na$ had greater radioactivity immediately after the design lifetime. However, their radioactivity level became negligible after six months due to their short half-life. The surface exposure dose rates of the canister and the main body of the metal cask from which the spent nuclear fuel had been removed with expiration of the design lifetime were determined to be at very low levels, and the radiation exposure doses to which radiation workers were subjected during the decommissioning process appeared to be at insignificant levels. The evaluations of this study strongly suggest that the nuclide inventory of a spent nuclear fuel metal cask can be utilized as basic data when decommissioning of a metal cask is planned, for example, for the development of a decommissioning plan, the determination of a decommissioning method, the estimation of radiation exposure to workers engaged in decommissioning operations, the management/reuse of radioactive wastes, etc.

• Radiation Oncology Journal
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• v.21 no.2
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• pp.174-181
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• 2003

Purpose: The target volume for the three field technique in breast cancer include the breast tangential and supraclavicular areas. The techniques rotating the gantry and couch angles, to match these two areas, will geometrically produce mismatching of the posterior edge between the medial and lateral tangential beams. This mismatch was confirmed by film dosimetry and three-dimensional computer planning. The correction methods of this mismatching were studied in this article. Materials and Methods: After the supraclavicular field was simulated using a half beam block and the medial and lateral tangential fields, by the rotation of the couch and gantry, we compared the following two methods to correct the mismatch. The first method was the rotation of coillmator until a line drawn on the posterior edge of tangential beams before the rotation of couch aligned the line drawn on the posterior edge after the rotation. The second method was the rotation of collimator according to the formula developed by the author as follows; Co=$2sin^{-1}${$sin\{theta}\{cdot}sin(C/2)$} (Co: collimator angle, $\theta$: angle between tangential beam and table, C: couch angle) Results: The film dosimetry showed the mismatching of posterior edges of the medial and lateral tangential fields prior to the rotation of collimator, while the posterior edges matched well after the rotation of collimator according to the formula. The three-dimensional computer plan also showed that the posterior edges matched well after the rotation of collimator accordingly. The DVH of the ipsilateral lung with the proper rotation of collimator angle was better than that without the rotation of collimator angle. Conclusion: The mismatching of the posterior edges of the medial and lateral tangential fields can be recognized on the three fileld technique in breast irradiation when the gantry and couch are simultaneously rotated and can be corrected with the proper rotation of the collimator angle. The radiation dose to the ipsilateral lung could be lowered with this technique.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.367-374
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• 2002

Purpose : To investigate the growth inhibitory effects, and the underlying mechanism of human colon cancer cell (HT-29) death, induced by a new synthetic bile acid derivative (HS-1200). Materials and Methods : Human colon cancer cells (HT-29), in exponential growth phase, were treated with various concentrations of a new synthetic bile acid derivative (HS-1200). The growth inhibitory effects on HT-29 cells were examined using a frypan blue exclusion assay. The extent of apoptosis was determined using agarose gel electrophoresis, TUNEL assays and Hoechst staining. The apoptotic cell death was also confirmed by Western blotting of PARP, caspase-3 and DNA fragmentation factor (DFF) analysis. To investigate the involvement of mitochondria, we employed immunofluorescent staining of cytochrome c and mitochondrial membrane potential analyses. Results : The dose required for the half maximal inhibition $(IC_{50})$ of the HT-29 cell growth was $100\~150\;{\mu}M$ of HS-1200. Several changes, associated with the apoptosis of the HT-29 cells, were reveal by the agarose gel eletrophoresis, TUNEL assays and Hoechst staining, following their treatment with $100\;{\mu}M$ of HS-1200. HS-1200 treatment also induced caspase-3, PARP and DFF degradations, and the western blotting showed the processed caspase-3 p20, PARP p85 and DFF p30 and p11 cleaved products. Mitochondrial events were also demonstrated. The cytochrome c staining indicated that cytochrome c had been released from the mitochondria in the HS-1200 treated cells. The mitochondrial membrane potential $(\Delta\Psi_m)$ was also prominently decreased in the HS-1200 treated cells. Conclusion : These findings suggest that the HS-1200 - induced apoptosis of human colon cancer cells (HT-29) is mediated via caspase and mitochondrial pathways.

• Journal of Radiation Protection and Research
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• v.35 no.1
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• pp.34-42
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• 2010

With the expanded use of radiation in modern medical practices, the most important issue in regards to efforts to reduce individual exposure dose is quality assurance. Therefore in order to study the present condition of quality assurance, the Gwangju Metropolitan City area was divided into five districts each containing ten hospitals. Four experiments were conducted: a reproducibility experiment for kVp, mA, and examination time (sec) intensity of illumination; half-value layer (HVL) measurement; and beam perpendicularity test matching experiment. The tube voltage reproducibility experiment for all fifty hospitals resulted in a 95.33% passing rate and mA and examination time both resulted in a 77.0% passing rate. The passing rate for intensity of illumination was 86.0% and 52.0% for HVL, which was the lowest passing rate of all four factors. For the beam perpendicularity test matching experiment, generally the central flux is matched to within $1.5^{\circ}$. Of all fifty hospitals 30.0% were beyond $3^{\circ}$. The results of the survey showed that 58% responded that they knew about quality assurance cycle. All fifty respondents stated that they have not received any training in regards to quality assurance at their current place of employment. Although quality assurance is making relative progress, the most urgent issue is awareness of the importance of quality assurance. Therefore, the implementation of professional training focusing on safety management and accurate quality assurance of radiation will reduce the exposure to radiation for radiologists and patients and higher quality imaging using less dosage will also be possible.

• Radiation Oncology Journal
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• v.12 no.3
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• pp.393-399
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• 1994

Spinal cord compression, an oncologic emergency, is a rare complication of hematologic malignancy Our experience was obtained with a series 32 Patients following retrospective analysis for assessing the role of radiation therapy and identifying the prognostic factors affecting on treatment outcome. Diagnosis was usually made by means of radiologic study such as myelography or computerized tomography (CT) or magnetic resonance imaging (MRI) and neurologic examination. Five cases were diagnosed by subjective symptom only with high index of suspicion. In 31 cases, the treatment consisted in radiation therapy alone and the remained one patient had laminectomy before radiation therapy because of diagnostic doubts. Total treatment doses ranged from 800 cGy to 4000 cGy with median of 2000 cGy. Initially large fraction size more than 250 cGy were used in 13 patients with rapidly progressed neurologic deficit. The clinical parameters considered in evaluating the response to treatment were backache, motor-sensory performance and sphincter function. Half of all patients showed good response. Partial response and no response were noted in $37.5\%$ and $12.5\%$, respectively. Our results showed higher response rate than those of other solid tumor series. The degree of neurologic deficit at that time of diagnosis was the most important predictor of treatment outcome. The elapsed time from development of symptoms to start of treatment was significantly affected on the outcome. But histology of primary tumor total dose and use of initial large fraction size were not significantly affect on the outcome. These results confirmed the value of early diagnosis and treatment especially in radiosensitive hematologic malignancy.

• Tuberculosis and Respiratory Diseases
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• v.52 no.2
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• pp.128-136
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• 2002

Background: There are few studies that have reported on the pharmacokinetic(PK) disposition of fluoroquinolones in patients with multi-drug resistant tuberculosis(MDR-Tb), even though fluoroquinolones are frequently co-prescribed to those patients. In this study, the PK disposition of ofloxacin, a fluoroquinolone, was evaluated in patients with MD R -Tb. Methods: Twenty patients with MDR-Tb were given 2nd line Tb drugs including ofloxacin (300mg twice a day), prothionamide, cycloserine, para-aminosalicylic acid, kanamycin, and streptomycin. The patients were grouped according to their body mass index(BMI) as an index of emaciation (group A : 18.5$\leq$BMI <23, group B : BMI < 18.5). Blood samples were serially drawn and urine samples were collected upto 24 hours after the last dose of those drugs at steady state (over 1 month). The ofloxacin concentrations were determined using HPLC (High Performance Liquid Chromatography). Results: The AUC of ofloxacin in group B was greater than that in group A ($31.4{\pm}8.9{\mu}g/ml{\cdot}h$ vs. $24.1{\pm}6.2{\mu}g/ml{\cdot}h$)(Check the symbols), (p<0.05). The total clearance(Cl/F) of ofloxacin was $0.16{\pm}0.03$ L/h/kg in group A, and $0.14{\pm}0.03$ L/h/kg in group B. The half-lives of ofloxacin in two groups were similar (group A : $5.3{\pm}0.8$ hours, group B : $5.7{\pm}0.9$ hours). In addition, the other PK parameters in two groups were also similar. Conclusions: The pharmacokinetics of ofloxacin in patients with MDR-Tb appears to be comparable with those of normal subjects, and the extent of emaciation appears to have an influence on the pharmacokinetics of ofloxaicn in chronic debilitated MDR-Tb patients.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.3
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• pp.416-426
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• 2005

Intravenous sedation have many advantages of rapid onset and recovery, ability of control sedation levels and duration through titration. Midazolam is most commonly used intravenous medication for sedation in pediatrics, endoscopy, oncologic procedures and so on. But in dentistry, midazolam intravenous sedation is usually for adult, and there are few reports for children. Todays, children who need sedation become more and older, intravenous sedation technique is going a matter of concern in pediatric dentistry. The purpose of this paper is to evaluate the efficacy of sedation and clinical success for different initial dosage of midazolam in intravenous sedation for pediatric dental patients. 16 healthy children (male 10, female 6), mean age $54.7{\pm}10.7$ months, who needed at least two separate treatment visits requiring local anesthesia were chosen for this study. Every children were taken 0.3mg/kg, maximum 5mg of midazolam by intramuscular route, and then 30~50% $N_2O-O_2$ for 10 minutes was given. On every visits, one of the following 2 different initial dosage was given by intravenous route : (1) Group I : 0.1mg/kg Midazolam (2) Group II : 0.2mg/kg Midazolam. Additional dosage was half of the first dose. Physiologic parameters (oxygen saturation, heart rate, respiratory rate, end-tidal carbon dioxide pressure) was recorded by ten procedure steps. Behavior was videotaped and rated using Ohio State University Behavioral Rating Scale and Automated Counting System by one investigator, blind to administered dosage. After the treatment, operator evaluated the clinical success. Physiologic parameters were stable and within normal range during treatment in both groups. The analyzed sedative effect, in behavioral evaluation, ratio of favorable Quiet was higher in group II, and clinical success rate of group II was better than group I. Induction time was rapid in group II, and recovery time was rapid in group I. And there was no statistically difference between two groups in every results.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.172-180
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• 2007

Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.