• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.233-240
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• 2004

Purpose: We developed a computer-aided classifier using artificial neural network (ANN) to discriminate the cerebral metabolic pattern of medial and lateral temporal lobe epilepsy (TLE). Materials and Methods: We studied brain F-18-FDG PET images of 113 epilepsy patients sugically and pathologically proven as medial TLE (left 41, right 42) or lateral TLE (left 14, right 16). PET images were spatially transformed onto a standard template and normalized to the mean counts of cortical regions. Asymmetry indices for predefined 17 mirrored regions to hemispheric midline and those for medial and lateral temporal lobes were used as input features for ANN. ANN classifier was composed of 3 independent multi-layered perceptrons (1 for left/right lateralization and 2 for medial/lateral discrimination) and trained to interpret metabolic patterns and produce one of 4 diagnoses (L/R medial TLE or L/R lateral TLE). Randomly selected 8 images from each group were used to train the ANN classifier and remaining 51 images were used as test sets. The accuracy of the diagnosis with ANN was estimated by averaging the agreement rates of independent 50 trials and compared to that of nuclear medicine experts. Results: The accuracy in lateralization was 89% by the human experts and 90% by the ANN classifier Overall accuracy in localization of epileptogenic zones by the ANN classifier was 69%, which was comparable to that by the human experts (72%). Conclusion: We conclude that ANN classifier performed as well as human experts and could be potentially useful supporting tool for the differential diagnosis of TLE.

• Economic and Environmental Geology
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• v.39 no.5 s.180
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• pp.555-566
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• 2006

Major, trace and rare earth elements data of the Cretaceous Jindong granitic rocks were investigated in order to constrain the magma source characteristics and to establish the paleotectonic environment of the southwestern part of the Gyeongsang Basin. Geochemical signatures of the granitic rocks from the study area indicate that all of the rocks have characteristics of calc-alkaline series in the subalkaline field, and progressively shift from metaluminous to peraluminous with differentiation. In the variation diagrams, the overall geochemical features of the granites show systematic variations in major and trace elements. Chondrite normalized REE patterns show generally enriched LREE((La/Yb)c=4.2-12.8) and slight negative to flat Eu anomalies. Rb-Sr isotope data of the Jindong granites show that the whole rock age and Sr initial ratio are $114.6{\pm}9.1Ma$ and 0.70457, respectively. The Sr initial ratio of the Jindong granites is very similar to those of the Creataceous granites from Masan, Kimhae and Busan area($^{87}Sr/^{86}Sr=0.7049-0.707$). These results suggest that the magma have the mantle signature and intruded into the area during the early Cretaceous age. The Jindong granites have higher $Al_{2}O_{3},\;Na_{2}O$, Sr and lower $K_{2}O$, Y concentrations compared with typical calc-alkaline granitic rocks. These adakitic signatures are similar to those of adakitic pluton on Kyushu Island, southwest Japan arc. On the ANK vs. ACNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type, VAG granite. Interpretations of the geochemical characteristics of the granitic rocks favor their emplacement at continental margin during the subduction of Izanagi plate.

• Clinical and Experimental Pediatrics
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• v.48 no.2
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• pp.186-190
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• 2005

Purpose : The purpose of this study was to evaluate the responses and toxicities of risk-adapted chemotherapy in pediatric intracranial germ cell tumors(IC-GCT). Methods : Fourteen patients who were diagnosed as IC-GCT from October 2002 to December 2003 received chemotherapy as an initial treatment modality. The low risk(LR) group was defined as follows : Pure germinoma and normal AFP level. Beta-hCG level 50 mIU/mL or less. The others belonged to the high risk(HR) group. Chemotherapy was composed of cisplatin, cyclophosphamide, etoposide and vincristine. Double doses of cisplatin and cyclophosphamide was used in HR patients. Results : Pathologic confirmation was done in all but one. Median age at diagnosis was 11.6 yr (1.2-18.7 yr), and nine patients belonged to the HR group. Tumor markers were normalized after chemotherapy in all patients whose tumor markers had been elevated. Four LR patients(80 percent) and seven HR patients(77.8 percent) showed complete response(CR) at the end of chemotherapy. An additional two of the three patients with partial response(PR) achieved CR after radiation therapy (RT), and the remaining one relapsed before RT. Four LR and all HR patients experienced infectious episodes that required hospitalization. Four of the nine HR patients(44.4 percent) suffered from tinnitus, three of whom developed sensorineural hearing loss. All but one are surviving, event-free, with a median follow-up of 13.9 mo(8.1-22.3 mo). Conclusion : Risk-adapted cisplatin-based chemotherapy was effective even in HR patients, but regimen modification seems to be necessary to avoid an unacceptably high toxicity rate.

• The Korean Journal of Nuclear Medicine
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• v.34 no.6
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• pp.456-464
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• 2000

Purpose: To evaluate the effect of acupuncture on regional cerebral blood flow (rCBF) at acupoints suggested by oriental medicine to be related to the treatment of cerebrovascular diseases. Materials and Methods: Rest/acupuncture-stimulation Tc-99m ECD brain SPECT using a same-dose subtraction method was performed on 54 normal volunteers (34 males, 20 females, age range from 18 to 62 years) using six paradigms: acupuncture at acupoints GV. 20, GV. 26, LI. 4, ST. 36 and SP. 6. In the control study, needle location was chosen on a non-meridian focus 1 cm posterior to the right fibular head. All images were spatially normalized, and the differences between rest and acupuncture stimulation were statistically analyzed using SPM$^{(R)}$ for Windows$^{(R)}$. Results: Acupuncture applied at acupoint GV. 20 increased rCBF in both the anterior frontal lobes, the right frontotemporal lobes, and the left anterior temporal lobe and the left cerebellar hemisphere. Acupuncture at GV 26 increased rCBF in the left prefrontal cortex. Acupuncture at LI. 4 increased rCBF in the left prefrontal and both the inferior frontal lobes, and the left anterior temporal lobe and the left cerebellar hemisphere. Acupuncture at ST. 36 increased rCBF in the left anterior temporal lobe, the right inferior frontal lobes, and the left cerebellum. Acupuncture at SP. 6 increased rCBF in the left inferior frontal and anterior temporal lobes. In the control stimulation, no significant rCBF increase was observed. Conclusion: The results demonstrated a correlation between stimulation at each acupoint with increase in rCBF to the corresponding brain areas.

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.30-40
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• 2004

Purpose: The aims of this study were to find brain regions in which gray matter volume was reduced and to show the capability of voxel-based morphometry (VBM) analysis for lateralizing epileptogenic zones in medial temporal lobe epilepsy (mTLE). The findings were compared with fluorodeoxyglucose positron omission tomography (FDG PET). Materials and Methods: MR T1-weighted images of 12 left mTLE and 11 right mTLE patients were compared with those of 37 normal controls. Images were transformed to standard MNI space and averaged in order to create study-specific brain template. Each image was normalized to this local template and brain tissues were segmented. Modulation VBM analysis was performed in order to observe gray matter volume change. Gray matter was smoothed with a Gaussian kernel. After these preprocessing, statistical analysis was peformed using statistical parametric mapping software (SPM99). FDG PET images were compared with those of 22 normal controls using SPM. Results: Gray matter volume was significantly reduced in the left amygdala and hippocampus in left mTLE. In addition, volume of cerebellum, anterior cingulate, and fusiform gyrus in both sides and left insula was reduced. In right mTLE, volume was reduced significantly in right hippocampus. In contrast, FDG uptake was decreased in broad areas of left or right temporal lobes in left TLE and right TLE, respectively. Conclusions: Gray matter loss was found in the ipsilateral hippocampus by modulation VBM analysis in medial temporal lobe epilepsy. This VBM analysis might be useful in lateralizing the epileptogenic zones in medial temporal lobe epilepsy, while SPM analysis of FDG PET disclosed hypometabolic epileptogenic zones.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.264-272
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• 2013

Climate changes have caused not only changes in the frequency and intensity of extreme climate events, but also temperature and precipitation. The damages on agricultural production system will be increased by heavy rainfall and snow. In this study we assessed vulnerability of crop cultivation facility and animal husbandry facility by heavy rain in 232 agricultural districts. The climate data of 2000 years were used for vulnerability analysis on present status and the data derived from A1B scenario were used for the assessment in the years of 2020, 2050 and 2100, respectively. Vulnerability of local districts was evaluated by three indices such as climate exposure, sensitivity and adaptive capacity, and each index was determined from selected alternative variables. Collected data were normalized and then multiplied by weight value that was elicited in delphi investigation. Jeonla-do and Gangwon-do showed higher climate exposures than the other provinces. The higher sensitivity to abnormal weather was observed from the regions that have large-scale cultivation facility complex compared to the other regions and vulnerability to abnormal weather also was higher at these provinces. In the projected estimation based on the SRES A1B, the vulnerability of controlled agricultural facility in Korea totally increased, especially was dramatic between 2000's and 2020 year.

• Investigative Magnetic Resonance Imaging
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• v.14 no.2
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• pp.103-114
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• 2010

Purpose : To generate a Korean specific brain template, especially in patients with Alzheimer's disease (AD) by optimizing the voxel-based analysis. Materials and Methods : Three-dimensional T1-weighted images were obtained from 123 subjects who were 43 cognitively normal subjects and patients with 44 mild cognitive impairment (MCI) and 36 AD. The template and the corresponding aprior maps were created by using the matched pairs approach with considering differences of age, gender and differential diagnosis (DDX). We measured several characteristics in both our and the MNI templates, including in the ventricle size. Also, the fractions of gray matter and white matter voxels normalized by the total intracranial were evaluated. Results : The high resolution template and the corresponding aprior maps of gray matter, white matter (WM) and CSF were created with the voxel-size of $1{\times}1{\times}1\;mm$. Mean distance measures and the ventricle sizes differed between two templates. Our brain template had less gray matter and white matter areas than the MNI template. There were volume differences more in gray matter than in white matter. Conclusion : Gray matter and/or white matter integrity studies in populations of Korean elderly and patients with AD are needed to investigate with this template.

• Radiation Oncology Journal
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• v.23 no.2
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• pp.92-97
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• 2005

Purpose : Reports on the outcome of curative radiotherapy for the primary hepatocellular carcinoma (HCC) are rarely encountered in the literature. in this study, we report our experience of a clinical trial where fractionated stereotactic radiotherapy (SRT) was used in treating a primary HCC. Materials and Methods : A retrospective analysis was peformed on 20 patients who had been histologically diagnosed as HCC and treated by fractionated SRT. The long diameter of tumor measured by CT was $2\~6.5$ cm (average: 3.8 cm). A single dose of radiation used in fractionated SRT was S or 10 Gy: each dose was prescribed based on the planning target volume and normalized to $85\~99\%$ isocenter dose. Patients were treated $3\~5$ times per week for 2 weeks, with each receiving a total dose of 50 Gy (the median dose: 50 Gy). The follow up period was $\~55$ months (the median follow up period: 23 months). Results : The response rate was $50\%$ (12 patients), with 4 patients showing complete response ($20%$), 8 patients showing partial response ($40\%$), and 8 patients showing stable disease ($40\%$). The 1-year and 2-year survival rates were $70.0\%$ and $43.1\%$, respectively, and the median survival time was 20 months. The 1-year and 2-year disease free survival rates were $65\%$ and $32.5\%$, respectively, and the median disease-free survival rate was 19 months. Some acute complications of the treatment were noted as follows: dyspepsia in 12 patients ($60\%$), nausea/emesis in 8 patients ($40\%$), and transient liver function impairment in 6 patients ($30\%$). However, there was no treatment related death. Conclusion : The study indicates that fractionated SRT is a relatively safe and effective method for treating primary HCC. Thus, fractionated SRT may be suggested as a local treatment for HCC of small lesion and containing a single lesion, when the patients are inoperable or operation is refused by the patients. We thought that fractionated SRT is a challenging treatment modality for the HCC.

• Tuberculosis and Respiratory Diseases
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• v.39 no.2
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• pp.120-130
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• 1992

Background: Although there have been many studies on the pathogenetic mechanism of acute lung injury, it is still elusive. Recently interests have been focused on the role of oxygen free radicals. But the effect of hydroxyl radical on the neutrophil mobilization and the alveolar-capillary permeability is not clear especially in the endotoxin-induced acute lung injury model of rats. This investigation was performed to evaluate the pathogenetic role of hydroxyl radical on the neutrophil accumulation into the lung and the increased alveolar-capillary permeability in the endotoxin-induced acute lung injury in rats. Method: Fifty rats were divided into four groups: vehicle control group (n=5, 6hrs; n=5, 24hrs), endotoxin-treated group (n=10, 6hrs; n=10, 24hrs), Dimethylthiourea (DMTU)-pretreated group (n=10, 6hrs), and deferoxamine (DFX)-pretreated group (n=10, 6hrs). Thirty minutes before sacrifice, $^{125}I$-tagged bovine serum albumin was injected. Six and twenty four hours after endotoxin injection, the rats were sacrificed, and the radioactivity of lung tissue and peripheral blood was counted. Permeability index was defined as the ratio of radioactivity between lung tissue and peripheral blood. Another set of rats (n=52) were divided into the same four groups as before [vehicle control group (n=5, 6hrs; n=5, 24hrs), endotoxin·treated group (n=7, 6hrs; n=8, 24hrs), DMTU-pretreated group (n=6, 6hrs; n=9, 24hrs), and DFX-pretreated group (n=5, 6hrs; n=7, 24hrs)], and were sacrificed 6 and 24 hours after endotoxin injection. In these rats, cell profile of peripheral blood and bronchoalveolar lavage fluid was evaluated, and the pathologic examination of lung tissue was performed. Results: 1) Increased alveolar-capillary permeability was observed 6 hours after endotoxin injection, which was normalized after 24 hours, and this increase was attenuated by pretreatment with DMTU and DFX. 2) Neutrophil sequestration into the lung was observed 24 hours after endotoxin administration, but this was not influenced by DMTU and DFX pretreatment. Conclusion: These results suggest that hydroxyl radical would not be involved in the sequestration of neutrophils into the lung, but plays an important role in the increase of alveolar-capillary permeability in the endotoxin-induced acute lung injury in rats.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.12 no.1
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• pp.23-29
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• 2009

Purpose: To provide the primary data for reaching a consensus on the adequate duration of treatment of lamivudine in children with HBeAg negative chronic hepatitis B. Methods: Seven of 83 children/adolescents with chronic hepatitis B were diagnosed with HBeAg-negative and HBV DNA-positive chronic hepatitis B and treated with lamivudine. Six children/adolescents were enrolled among 7 patients, who had been treated with lamivudine over 2 years. The primary goal of treatment was HBV DNA clearance and normalization of the serum ALT level; the final goal of treatment was the durability of the complete response after discontinuation of lamivudine. It was planned to continue lamivudine for more than two additional years after HBV DNA negativity and normalization of ALT. Results: The mean duration of lamivudine treatment was 32.2 months (range, 26~40 months) and the mean duration of follow-up was 59.5 months (range, 26~110 months). HBV DNA levels became undetectable (<0.5 pg/mL) in 6 patients within 3 months of treatment. ALT levels were normalized in 3.5 months (range, 2~7 months) in all 6 patients. Biochemical breakthrough developed in 1 patient 18 months after the initiation of lamivudine treatment. No evidence of relapse could be found in 4 patients with a mean follow-up of 23.8 months (range, 4~75 months) after cessation of lamivudine treatment. Conclusion: Suppression of HBV replication and normalization of serum ALT levels were effectively achieved with long-term lamivudine treatment in children/adolescents with HBeAg-negative chronic hepatitis B. Two additional years of lamivudine may be needed after HBV DNA clearance and ALT normalization in HBeAg-negative chronic hepatitis B in order to decrease the relapse rate.