• Radiation Oncology Journal
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• v.22 no.1
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• pp.55-63
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• 2004

Purpose : To evaluate the reflection of tumor motion according to the planning CT scan time. Material and Methods : A model of N-shape, which moved aiong the longitudinal axis during the ventilation caused by a mechanical ventilator, was produced. The model was scanned by planning CT, while setting the relative CT scan time (T: CT scan time/ventilatory period) to 0.33, 0.50, 0.67, 0.75, 1.00, 1.337, and 1.537. In addition, three patients with non-small cell lung cancer who received stereotactic radiosurgery In the Department of Radiation Oncology, Asan Medical Center from 03/19/2002 to 05/21/2002 were scanned. Slow (10 Premier, Picker, scan time 2.0 seconds per slice) and fast CT scans (Lightspeed, GE Medical Systems, with a scan time of 0.8 second per slice) were peformed for each patient. The magnitude of reflected movement of the N-shaped model was evaluated by measuring the transverse length, which reflected the movement of the declined bar of the model at each slice. For patients' scans, all CT data sets were registered using a stereotactic body frame scale with the gross tumor volumes delineated in one CT image set. The volume and three-dimensional diameter of the gross tumor volume were measured and analyzed between the slow and fast CT scans. Results : The reflection degree of longitudinal movement of the model increased in proportion to the relative CT scan times below 1.00 7, but remained constant above 1.00 T Assuming the mean value of scanned transverse lengths with CT scan time 1.00 T to be $100\%$, CT scans with scan times of 0.33, 0.50, 0.57, and 0.75 T missed the tumor motion by 30, 27, 20, and $7.0\%$ respectively, Slow (scan time 2.0 sec) and Fast (scan time 0.8 sec) CT scans of three patients with longitudinal movement of 3, 5, and 10 mm measured by fluoroscopy revealed the increases in the diameter along the longitudinal axis Increased by 6.3, 17, and $23\%$ in the slow CT scans. Conculsion : As the relative CT scan time increased, the reflection of the respiratory tumor movement on planning CT also Increased, but remained constant with relative CT scan times above 1.00 T When setting the planning CT scan time above one respiration period (>1.00 T), only the set-up margin is needed to delineate the planning target volume. Therefore, therapeutic ratio can be increased by reducing the radiation dose delivered to normal lung tissue.

• Radiation Oncology Journal
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• v.25 no.3
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• pp.170-176
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• 2007

Purpose: To determine the role of radiotherapy for the treatment of portal vein thrombosis (PVT) from hepatocellular carcinoma (HCC). Material and Methods: A retrospective analysis was performed on 70 patients that had been diagnosed with HCC and were treated with three-dimensional conformal radiotherapy (3D-CRT) for the PVT. The radiation dose ranged from 40 Gy to 60 Gy (median dose: 48 Gy) and the biological effective dose (BED) ranged from 31.3 Gy to 78.0 $Gy_{10}$ (median dose: 61.6 $Gy_{10}$). Response was determined by measuring the extent of the PVT on a CT image at 0, 1 and 3 months after completion of the radiotherapy. The median follow-up period was 9 months. Results: The response rate was 47.1% (33 patients), with two patients (2.9%) showing a complete response, 31 patients (44.3%) showing a partial response, and 35 patients (50%) showing stable disease or no response. The 1-year progression-free survival rate was 60%, and the median progression-free survival time was 17 months. The median overall survival time was 11 months, the median survival time in the responders was 15 months and in the nonresponders was 8 months (p=0.032). Four patients (5.7%) had transient liver function impairment during treatment. Radiation induced liver disease (RILD) was observed in only one patient (1.4%). Conclusion: Three-dimensional conformal radiotherapy for the treatment of PVT from advanced HCC was a relatively effective and safe method.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.349-357
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• 2010

Purpose : Transient tachypnea of the newborn (TTN) is usually benign and improves within 72 hours. However, it can also progress to prolonged tachypnea over 72 hours, profound hypoxemia, respiratory failure, and even death. The aim of this study is to find predictable risk factors and describe the clinical courses and outcomes of prolonged TTN (PTTN). Methods : The medical records of 107 newborns, >$35^{+0}$ weeks of gestational age with TTN, who were admitted to the NICU at Seoul Asan Medical Center from January 2001 to September 2007 were reviewed. They were divided into 2 groups based on duration of tachypnea. PTTN was defined as tachypnea ${\geq}72$ hours of age, and simple TTN (STTN) as tachypnea <72 hours of age. We randomly selected 126 healthy-term newborns as controls. We evaluated neonatal and maternal demographic findings, and various clinical factors. Results : Fifty-five infants (51%) with total TTN were PTTN. PTTN infants had grunting, tachypnea >90/min, $FiO_2$ >0.4, and required ventilator care more frequently than STTN infants. PTTN had lower level of serum total protein and albumin than STTN. The independent predictable risk factors for PTTN were grunting, maximal respiration rate >90/min, and $FiO_2$ >0.4 within 6 hours of life. Conclusion : When a newborn has grunting, respiration rate >90/min, and oxygen requirement >0.4 of $FiO_2$ within 6 hours of life, the infant is at high risk of having persistent tachypnea ${\geq}72$ hours. We need further study to find the way to reduce PTTN.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.323-328
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• 2010

Purpose : To verify the effect of hyperglycemia on mortality rates in critically ill children and to identify the blood glucose level that influences prognosis. Methods : From July 2006 to June 2008, a total of 206 patients who were admitted to the pediatric intensive care unit (PICU) at Asan Medical Center and who survived for more than 7 days were retrospectively reviewed. We analyzed the maximum glucose value within 7 days in PICU, PRISM-III score and SOFA score within 24 hours, and mortality. We did not perform an adjustment analysis of drugs affecting glucose level. Results : The maximum glucose level within 7 days in PICU was higher in the nonsurvival group than in the survival group. Using 4 cutoff values (125, 150, 175, and 200 mg/dL), the mortality of patients with hyperglycemia was found to be 13.0 %, 14.4%, 19.8%, and 21.1%, respectively, and the cutoff values of 175 and 200 mg/dL revealed significant differences in mortalities between the hyperglycemic and normoglycemic groups. The PRISM-III score was not significantly different between the hyperglycemic and normoglycemic groups under a glucose cutoff value of 175 mg/dL, but the SOFA score was higher in the hyperglycemic group. Under a glucose cutoff value of 200 mg/dL, the PRISM-III score was higher in the hyperglycemic group, and the SOFA score did not differ between the 2 groups. Conclusion : Hyperglycemia with a maximal glucose value ${\geq}175\;mg/dL$ during the first 7 days after PICU admission was associated with increased mortality in critically ill children.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.1
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• pp.5-12
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• 2018

As many local governments have faced increasing conflicts on landfill use and the time of end use, it is difficult to provide an alternative landfill or conclude a consensus of lifespan extension for the existing landfill site. Therefore, the purpose of this study is to contribute improving of the landfill capacity by calculating the resource recovery potentials of landfilled waste previously and in the future by landfill mining. For this, rate of volume increase, weight ratio, and apparent density were adopted as major parameters and their values were calculated through previous cases. The rate of volume increase was calculated to 1.42 by averaging previous cases of three areas. The average weight ratio of soil matter was 45.6% by calculating for the three areas. For the combustible waste and incombustible waste, statistical data can be used. The apparent densities were divided by combustible waste, incombustible waste, and soil matter using an average of two areas value, i.e., $0.35ton/m^3$, $1.40ton/m^3$ and $1.58ton/m^3$. We analyzed the resource recovery potential of Cheongju landfill by using the estimated parameters. The additional landfill capacity was 45% of the existing landfill capacity by recovering landfilled waste by landfill mining. In addition, it is analyzed that the lifespan is extended to 20 years, if the combustible waste of new inputting waste is sorted and combusted for energy recovery and incineration ash, incombustible waste, and soil matter are only reclaimed into the existing Cheongju landfill. It is expected that the methodology and parameters of this study will be used as basic data when resource recovery potential is analyzed for another case study of landfill mining.

• Journal of Gastric Cancer
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• v.6 no.1
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• pp.1-5
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• 2006

Purpose: A proximal gastrectomy is performed for gastric cancer in the upper part of the stomach to preserve the function of the stomach after surgery. An esophagogastrostomy is one of the common reconstruction methods for a proximal gastrectomy, but this method results in a high incidence of reflux esophagitis. This study was undertaken to compare subjective and functional results between esophagogastrostomy and jejunal interposition reconstructions. Materials and Methods: From June 1998 to December 2002, proximal gastrectomies were performed in 33 patients with tumors in the upper third of the stomach; 8 had reconstruction using jejunal interposition between the esophagus and the remnant stomach (JI group) while 25 had reconstruction using esophagogastrostomy (EG group). The postroperative courses of the patients were reviewed in terms of symptoms, weight changes, and endoscopic findings. Results: The mean age of the patients was 59 years; 26 were men and 7 were women. There were no significant differences in general complications, operating times, or histologic features between the two groups. Fifty-two percent (52%) of the EG group complained of dysphagia, and 16% them experienced heartburn and acid belching. Twelve percent (12%) of the JI group complained of dysphagia, but heartburn and acid belching did not occur. Incidences of reflux esphagitis (36%) and balloon dilatation for anastomotic stricture (16%) were more common in the EG group than in the JI group (0% and 12%). Conclusion: To prevent or minimize complications, such as reflux esophagitis and postoperative symptoms, a proximal gastrectomy with a jejunal interposition is an alternative method as an organ-preserving surgical strategy to improve quality of life for patients. (J Korean Gastric Cancer Assoc 2006;6:1-5)

• Tuberculosis and Respiratory Diseases
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• v.62 no.2
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• pp.98-104
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• 2007

Background: Although there is an increasing incidence of Mycobacterium abscessus pulmonary disease in Korea, the optimal therapeutic regimen has not yet been established and there are no reports of the long-term treatment outcomes. This study examined the long-term treatment outcomes of M. abscessus pulmonary disease. Methods: Twenty-nine patients diagnosed with M. abscessus pulmonary according to the American Thoracic Society criteria and treated from January 1996 to December 2003 were enrolled in ghis study. The clinical characteristics, radiological findings, treatment outcome, and follow up data were analyzed retrospectively. Results: The mean age of the 29 patients was 56.1 (${\pm}13.6$) years and there was a female (22/29) dominance. The chest radiography revealed the nodular bronchiectatic type to be dominant (69%, 20/29). Twenty-seven (93.1%) were prescribed clarithromycin-containing regimens, and injectable drugs, mainly aminoglycosides, were included in the regimen of nineteen patients. The most predominant regimen (48.3%) consisted of clarithromycin and amikacin. The treatment success, failure, and default were achieved in 19(65.5%), 9(31.0%), and 1(3.4%), respectively. The median duration to culture conversion was 42 days (range 15-362) and the median duration of treatment in the success group was 543 days (range 176-1,160). An adjunctive surgical resection was performed in five patients, which resulted in treatment success in two patients. After the completion of treatment, nineteen patients were followed up for a median duration of 931 days (range 230-2,294). Only one (5.3%) patient relapsed 45 days after completing treatment. Conclusion: Treatment with clarithromycin-containing regimens resulted in a successful treatment in approximately two thirds of patients with M. abscessus pulmonary disease. The long-term relapse rate was also quite low.

• Tuberculosis and Respiratory Diseases
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• v.62 no.2
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• pp.113-118
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• 2007

Background: Paraquat is known to induce oxidant injury that results in multiorgan failure and lung fibrosis. Iron has been considered to play a key role in paraquat-induced oxidant lung injury. This study examined the effect of deferoxamine, an iron-chelating agent, in the treatment of paraquat poisoning. Methods: From September, 2001 to April, 2005, 28 patients with paraquat poisoning who were admitted at a medical intensive care unit of a University-affiliated hospital, were enrolled in this study. Sixteen patients were treated according to the paraquat poisoning treatment guidelines and 12 received an intravenous infusion of deferoxamine in addition to the treatment guidelines. Results: There were no differences between the two groups in terms of age, gender, severity of paraquat poisoning, and the time elapsed from ingestion to presentation at hospital. There was no difference in overall mortality between the two groups but the incidence of respiratory failure in the deferoxamine group was higher than in the conventional group(4/7 versus 0/9, p=0.019). Conclusion: Deferoxamine seems to have no clinical benefit compared with the conventional treatment.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1245-1255
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• 1997

Background : Rifampicin(RFP) is a key component of the antituberculous short-course chemotherapy and the RFP resistance is a marker of multi-drug resistant(MDR) tuberculosis. RPoB gene encodes the $\beta$-subunit of RNA polymerase of M. tuberculosis which is the target of RFP. And rpoB gene mutations are the cause of RFP resistance of M. tuberculosis. Although several reports showed that PCR-SSCP would be a rapid diagnostic method for identifying the RFP resistance, there were few reports Performed using direct, clinical specimens. So we Performed PCR-SSCP analysis of rpoB gene of M. tuberculosis in direct, clinical specimens. Methods : 75 clinical specimens were collected from patients at Asan Medical Center from June to August 1996. After PCR of IS 6110 fragments, 43 both AFB smear-positive and IS6110 fragment PCR-positive specimens were evaluated. The RFP susceptibility test was referred to the referral laboratory of the Korean Tuberculosis Institute. DNA was extracted by bead beater method. And heminested PCR was done using 0.1ul(1uCi) [$\alpha-^{32}P$]-dCTP. SSCP analysis was done using non-denaturating MDE gel electrophoresis. Results : The results of PCR of IS6110 fragments of M. tuberculosis were positive in 55(73%) cases of 75 AFB smear-positive clinical specimens. Of the 55 specimens, RFP susceptibility was confirmed in only 43 specimens. Of the 43 AFB smear-positive and IS6110 fragment-positive specimens, 29 were RFP susceptible and 14 were RFP resistant. All the RFP susceptible 29 strains showed the same mobility compared with that of RFP sensitive H37Rv in SSCP analysis of ropB gene. And all the other RFP resistant 13 strains showed the different mobility. In other words they showed 100% identical results between PCR-SSCP analysis and traditional susceptibility test. Conclusion : The PCR-sseP analysis of rpoB gene in direct clinical specimens could be used as a rapid diagnostic method for detecting RFP resistant M. tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.58 no.4
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• pp.385-391
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• 2005

Background : The incidence of nontuberculous mycobacterium (NTM) infections in Korea is increasing. This retrospective study was performed to examine the recovery rate of NTM from respiratory specimens as well as the isolated NTM colony characteristics, and to assess the clinical significance of a NTM isolation. Methods : The results of the respiratory specimens requested for an acid-fast bacilli (AFB) examination during 2002 at Asan Medical Center, along with the patients clinical characteristics were analyzed. Results : A total 26,820 respiratory specimens were requested for the acid-fast bacilli (AFB) smear and culture during the study period. The proportion of M. tuberculosis and NTM isolation was 5.7% and 2.2%, respectively. Among the AFB smear and culture positive specimens, 12.2% were found to be NTM. The scotochromogen showing a low colony count < 20, which appeared to be contaminants, were isolated in 31.8% of the 584 NTM isolates. Excluding the low-colony scotochromogens, the M. avium-intracellulare complex was the most common NTM isolates (42.1%), and was also the most common causative organism for NTM pulmonary diseases. 8.4% (23/275) and 17.8% (49/275) of patients with NTM isolates met the American and British Thoracic Society diagnostic criteria for NTM pulmonary disease, respectively. Conclusion : In case of a positive AFB-smear or culture result, the possibility of NTM being a causative organism should always be considered, even in Korea, which has an intermediate incidence of tuberculosis.