Publications (17)34.16 Total impact
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Article: Feasibility of proposed single-nucleotide polymorphisms as predictive markers for targeted regimens in metastatic colorectal cancer.
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ABSTRACT: Background:Surrogate biomarkers for metastatic colorectal cancer (mCRC) are urgently needed to achieve the best outcomes for targeted therapy.Methods:A clinical association analysis was performed to examine the three single-nucleotide polymorphisms (SNPs) that were previously proposed as markers of chemosensitivity to the cetuximab (124 patients) and bevacizumab regimens (100 patients) in mCRC patients. In addition, biological correlations were examined for the candidate SNPs in terms of their regulatory pathway.Results:For cetuximab regimens, patients homozygous for the wild-type alleles (GG) of LIFR rs3729740 exhibited a 1.9 times greater overall response rate (ORR) and 1.4 months longer progression-free survival (PFS) than those homozygous or heterozygous for the mutant allele (GA and AA; P=0.022 and 0.027, respectively). For bevacizumab regimens, patients homozygous for the minor alleles (TT) of ANXA11 rs1049550 exhibited an ORR twice as high as those homozygous or heterozygous for the ancestral allele (CC and CT; P=0.031). Overall response rate gain was achieved up to 10% in patients with wild-type LIFR rs3729740 patients either with wild-type KRAS or skin toxicity (P=0.001) respectively. Specifically in clones treated with cetuximab and bevacizumab regimens, active p-ERK and MMP-9 expressions were significantly reduced in clones expressing wild-type LIFR rs3729740 (P=0.044) and in those expressing minor-type ANXA11 rs1049550 (P=0.007), respectively.Conclusion:LIFR rs3729740 and possibly ANXA11 rs1049550 may be useful as biomarkers for predicting whether mCRC patients are sensitive to relevant target regimens, although further validation in large cohorts is needed.British Journal of Cancer advance online publication, 11 April 2013; doi:10.1038/bjc.2013.163 www.bjcancer.com.British Journal of Cancer 04/2013; · 5.04 Impact Factor -
Article: Open label, three period, single sequence, study of 5, 25, 50 mg sertraline pharmacokinetics in healthy male Korean volunteers.
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ABSTRACT: Sertraline is a naphthalenamine derivative which has the effect of selective serotonin reuptake inhibition. It has been used for major depression, and obsessive compulsive disorder. This study was performed to evaluate the pharmacokinetic (PK) characteristics after the administration of low dose sertraline for the purpose of exploring an application of microdosing methods in PK studies. An open-label, three-period, single-sequence, dose-escalation study was performed in 6 healthy Korean male volunteers. Subjects were administered a single dose of 5 mg, 25 mg and 50 mg sertraline orally in each period, with 1 week washouts between periods. Blood samples were obtained up to 96 h after drug administration. Plasma concentrations were determined using high performance liquid chromatography-tandem mass spectrometry. PK parameters of sertraline were analyzed using non-compartmental methods. A total of 6 subjects completed the study. After the administration of sertraline at 5 mg, 25 mg and 50 mg, the median tmax were 6.0, 6.0 and 4.0 h and the mean (SD) elimination half-lives were 31.9 (6.5), 27.2 (6.7) and 28.0 (6.6) h, respectively. The AUC and Cmax increased dose-dependently. The dose-normalized mean (SD) AUC and Cmax were different in each dosing group (p < 0.01) with 2.0 (0.8), 5.3 (1.2) and 6.0 (1.9) mg × hr/l/mg in the 5 mg, 25 mg and 50 mg groups for dose-normalized AUC, and 0.07 (0.01), 0.18 (0.05) and 0.21 (0.08) mg/l/mg in the 5 mg, 25 mg and 50 mg groups for dose-normalized Cmax, respectively, which indicates a lack of dose proportionality. A lack of dose proportional properties was shown in the 5 mg dose relative to the 25 mg and 50 mg doses of sertraline. This shows that the PK parameters for low-dose sertraline could be different from those in clinical concentrations.International journal of clinical pharmacology and therapeutics 11/2011; 49(11):672-8. · 1.18 Impact Factor -
Article: Homologous expression and quantitative analysis of T3SS-dependent secretion of TAP-tagged XoAvrBs2 in Xanthomonas oryzae pv. oryzae induced by rice leaf extract.
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ABSTRACT: Xanthomonas oryzae pv. oryzae (Xoo) produces a putative effector, XoAvrBs2. We expressed XoAvrBs2 homologously in Xoo with a TAP-tag at the C-terminus to enable quantitative analysis of protein expression and secretion. Addition of rice leaf extracts from both Xoo-sensitive and Xoo-resistant rice cultivars to the Xoo cells induced expression of the XoAvrBs2 gene at the transcriptional and translational levels, and also stimulated a remarkable amount of XoAvrBs2 secretion into the medium. In a T3SS-defective Xoo mutant strain, secretion of the TAPtagged XoAvrBs2 was blocked. Thus, we elucidated the transcriptional and translational expressions of the XoAvrBs2 gene in Xoo was induced in vitro by the interaction with rice and the induced secretion of XoAvrBs2 was T3SSdependent. It is the first report to measure the homologous expression and secretion of XoAvrBs2 in vitro by rice leaf extract. Our system for the quantitative analysis of effector protein expression and secretion could be generally used for the study of host-pathogen interactions.Journal of Microbiology and Biotechnology 07/2011; 21(7):679-85. · 1.38 Impact Factor -
Article: Improvement of initial vacuum condition along 2008-2010 KSTAR campaign by vessel baking
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ABSTRACT: Korea Superconducting Tokamak Advanced Research (KSTAR) is upgraded for its KSTAR 3rd campaign for new target mission to produce the D-shaped plasma with a target plasma current of 500 kA and/or pulse length of 5 s. New Plasma Facing Components (PFCs) are installed which leads to the increase of the surface area of the vessel by a factor of about 5. The vacuum conditioning such as the vessel baking has been performed in order to remove various kinds of impurities including H2O, carbon and oxygen for the plasma. The total outgassing rate in the KSTAR 1st campaign was measured as 1.5 × 10−4 mbar ℓ s−1 which is increased by a factor of 3 (6.49 × 10−4 mbar ℓ s−1) in the KSTAR 3rd campaign. Nevertheless, the outgassing rates per unit area have been decreased from 9.31 × 10−5 mbar ℓ m−2 s−1 to 1.22 × 10−5 mbar ℓ m−2 s−1 due to the upgrade of baking system and series of baking operationFusion Engineering and Design 05/2011; 86:671. · 1.49 Impact Factor -
Article: Transarterial chemoembolization versus supportive therapy in the palliative treatment of unresectable intrahepatic cholangiocarcinoma.
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ABSTRACT: To evaluate the clinical outcome and the survival benefits of transarterial chemoembolization (TACE) for unresectable intrahepatic cholangiocarcinoma (ICC) compared with supportive therapy. From January 1996 to April 2009, a total of 155 patients with unresectable ICC met the entry criteria and underwent TACE (72 patients) or supportive treatment (83 patients). Their survival was the primary end point. The baseline patients and tumour characteristics were well-balanced in the two groups. The median number of sessions per patient was 2.5 (range 1-17 sessions) in the TACE group. After TACE, the incidence of significant (≥ grade 3) haematological and non-haematological toxicities was 13 and 24%, respectively, and no patients died within 30 days following TACE. The objective tumour regression (≥ partial response) was achieved in 23% of the patients in the TACE group. The Kaplan-Meier survival analysis showed that the survival period was significantly longer in the TACE group (median 12.2 months) than in the symptomatic treatment (median 3.3 months) group (p < 0.001). TACE is safe and offers greater survival benefits than supportive treatment for the palliative treatment of unresectable ICC.Clinical radiology 04/2011; 66(4):322-8. · 1.65 Impact Factor -
Article: Phase II study of S-1 combined with oxaliplatin as therapy for patients with metastatic biliary tract cancer: influence of the CYP2A6 polymorphism on pharmacokinetics and clinical activity.
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ABSTRACT: Advanced biliary cancer is often treated with fluoropyrimidine-based chemotherapy. In this study, we evaluated the efficacy and tolerability of a combination of S-1, an oral fluoropyrimidine prodrug, and oxaliplatin in patients with metastatic biliary cancer. Patients with histologically confirmed metastatic biliary cancer and no history of radiotherapy or chemotherapy were enrolled. Oxaliplatin was administered intravenously (130 mg m(-2)), followed by 14-day administration of oral S-1 (40 mg m(-2) twice daily) with a subsequent 7-day rest period every 21 days. Pharmacokinetic analysis of S-1 was performed at cycle 1. Patients were genotyped for CYP2A6 polymorphisms ((*)1, (*)4, (*)7, (*)9 or (*)10), and pharmacokinetic and clinical parameters compared according to the CYP2A6 genotype. In total, 49 patients were evaluated, who received a median of four cycles. The overall response rate was 24.5%. Median progression-free and overall survival was 3.7 and 8.7 months, respectively. The most common haematological grade 3 out of 4 toxicity was neutropenia (14%), while non-hematological grade 3 out of 4 toxicities included anorexia (14%), nausea (12%), asthenia (10%), vomiting (10%), and diarrhoea (4%). Biotransformation of S-1 (AUC(0-24 h) of 5-fluorouracil/AUC(0-24 h) of tegafur) was 1.85-fold higher for the *1/*1 group than for the other groups (90% confidence interval 1.37-2.49). Diarrhoea (P=0.0740), neutropenia (P=0.396), and clinical efficacy (response rate, P=0.583; PFS, P=0.916) were not significantly associated with CYP2A6 genotype, despite differences in 5-FU exposure. The combination of S-1 and oxaliplatin appears to be active and well tolerated in patients with metastatic biliary cancer, and thus is feasible as a therapeutic modality. CYP2A6 genotypes are associated with differences in the biotransformation of S-1. However, the impact of the CYP2A6 polymorphism on variations in clinical efficacy or toxicity requires further evaluation.British Journal of Cancer 02/2011; 104(4):605-12. · 5.04 Impact Factor -
Article: Quench Simulation and Detection in KSTAR PF Magnet System
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ABSTRACT: To detect quenches in the Poloidal Field (PF) magnet system is more difficult than the Toroidal Field (TF) magnet system due to excessively high inductive voltages generated by PF pulse-currents and plasma currents. According to reference scenarios being considered so far, the maximum voltage across the PF coils is inductively generated up to about 3.5 kV during the start of plasma (SoP) stage in a very short time period. The voltage measured by compensation of the inductive voltage should be below a certain level which is called as the quench voltage threshold. However, the compensated voltage might be higher than the threshold even with the well-designed compensation schemes. Accordingly, the quench voltage threshold and the quench protection delay time should be properly determined for the quench detection not to take a false action which could cause the fast energy discharge. From the quench simulation using the calculation of hot spot temperature and the resistive voltage growth as a function of time, the proper values of the quench detection parameters of the PF magnet system were derived for the maximum hot temperature rise to be limited within 150 K.IEEE Transactions on Appiled Superconductivity 07/2010; · 1.04 Impact Factor -
Article: First Commissioning Results of the KSTAR Cryogenic System
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ABSTRACT: The cryogenic system for the KSTAR superconducting (SC) magnets has been commissioned. It consists of a cold box, distribution boxes (DB) and cryogenic transfer lines. The cold box and DB #1 provide 600 g/s of supercritical helium to cool the SC magnets, their SC bus-lines, and the magnet support structures. It also provides 17.5 g/s of liquid helium to the current leads and supplies cold helium flow to the thermal shields. The main duties of the DB #2 are the relative distribution of the cryogenic helium among the cooling channels of each KSTAR cold component and the emergency release of over-pressurized helium during abnormal events such as quenches of the SC magnets. After individual commissioning, the system was integrated and cooled down with the KSTAR device. In this paper, the construction and commissioning results of the KSTAR cryogenic system will be introduced. In addition, we will present the cool-down results of the KSTAR device.IEEE Transactions on Appiled Superconductivity 07/2009; · 1.04 Impact Factor -
Article: Wall conditioning of the KSTAR vacuum vessel
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ABSTRACT: The wall conditioning of the KSTAR vacuum vessel has been performed in order to remove various kinds of impurities including H2O, carbon and oxygen for the first plasma. The first step of the wall conditioning was baking to 100 by hot pressurized water which circulates through the water channels between inner and outer wall of the vacuum vessel. The baking process continued for more than 200 h. Next step of the wall conditioning was the R-GDC with both hydrogen and helium. The R-GDC was operated in low level of 10−3 mbar range. The partial pressure analysis showed that the R-GDC in the baking process is satisfactory and efficient and the outgassing rate is remarkably reduced. In addition to the R-GDC, the ICRH discharge cleaning under 1.5 T of the toroidal field is performed between plasma shots.Fusion Engineering and Design. 04/2009; 84:1026-1028. -
Article: Korea Superconducting Tokamak Advanced Research vacuum and gas puffing system.
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ABSTRACT: A piezoelectric valve, which has a flow rate of about 463 mbar l/s, has been installed to fuel the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. The valve flow rate is in situ calibrated by analyzing the pressure rise curve while fueling the vessel at a constant rate. The calibration method and results are presented. In addition to the flow rate, other vacuum system parameters, such as the pumping speed and the vessel volume, were experimentally obtained. Based on these measurements, a KSTAR vacuum system simulator was developed to calculate the valve drive signal to obtain a programmed pressure trace. An arbitrarily shaped pressure trace was successfully controlled in KSTAR with this hardware and software system.The Review of scientific instruments 12/2008; 79(11):116103. · 1.52 Impact Factor -
Article: Accuracy of magnetic resonance cholangiopancreatography for locating hepatolithiasis and detecting accompanying biliary strictures.
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ABSTRACT: Magnetic resonance cholangiopancreatography (MRCP) is rapidly replacing diagnostic endoscopic retrograde cholangiopancreatography (ERCP) in various pancreaticobiliary diseases. This study was designed to evaluate the accuracy of MRCP in detection of hepatolithiasis and accompanying biliary strictures. A prospective study over 2 years was conducted in 66 patients with primary intrahepatic stones. All patients with hepatolithiasis underwent percutaneous transhepatic cholangioscopy (PTC) within 2 weeks of the MRCP examination. The MRCP findings were compared with those of PTC as the reference standard for assessing the location of intrahepatic stones and the presence or absence of accompanying biliary strictures. The sensitivity, specificity, and accuracy of MRCP for detecting and locating intrahepatic stones were 97 %, 99 %, and 98 %, respectively. The sensitivity, specificity, and accuracy of MRCP for detecting and locating intrahepatic bile duct strictures were 93 %, 97 %, and 97 %, respectively. During PTC, six of the 66 patients (9 %) were found on histology to have intraductal cholangiocarcinoma in stone-bearing ducts, which had not been suspected on MRCP. In this study, MRCP allowed intrahepatic stones and accompanying biliary strictures to be located accurately. MRCP may therefore be able to replace diagnostic ERCP in patients with primary intrahepatic stones. However, MRCP had a limited ability to reveal concurrent intraductal cholangiocarcinoma associated with hepatolithiasis.Endoscopy 12/2004; 36(11):987-92. · 5.21 Impact Factor -
Article: Selective solid-phase extraction of polycyclic aromatic hydrocarbons by the chemically modified polymeric adsorbents with protoporphyrin IX
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ABSTRACT: The chemically modified polymeric adsorbents were evaluated for selective solid-phase extraction of polycyclic aromatic hydrocarbons. Commercially available Amberlite XAD-2 and XAD-4 resins were modified with macrocyclic protoporphyrin IX or tetrakis(p-carboxyphenyl)-porphyrin through the ketone linkage. The variables that influence the selectivity and recovery of the solid-phase extraction were optimized. The best result was obtained with XAD-4 resins modified with macrocyclic protoporphyrin IX. After preconcentration and clean-up step, the polycyclic aromatic hydrocarbons were determined by gas chromatography with mass spectrometric detection. The method was used to determine polycyclic cromatic hydrocarbons in soil, and the recovery was in the range of 79.6% to 94.1%.Chromatographia 04/2003; 57(9):665-670. · 1.20 Impact Factor -
Article: Evaluation on the adsorption capabilities of new chemically modified polymeric adsorbents with protoporphyrin IX.
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ABSTRACT: A chemically modified polymeric adsorbent was synthesized to evaluate the availability as an adsorbent for solid-phase extraction (SPE) of phenol and chlorophenols. Commercially available Amberlite XAD-2 and XAD-4 resins were modified with macrocyclic protoporphyrin IX (PPIX) through the ketone linkage. Adsorption isotherms were obtained by batch experiments and the data were fitted to the Freundlich equation to calculate the adsorption parameters. Breakthrough volumes were measured by column experiments. Physical properties such as surface area, average pore diameter and micropore volume of resins were measured to correlate with the adsorption characteristics. As a result, adsorption capacity was increased for the chemically modified resins and it can be concluded that the increase of pi-pi interaction due to the introduction of the porphyrin molecule is the major factor for the increase of the adsorption capacity.Journal of Chromatography 06/2001; 917(1-2):87-93. · 4.53 Impact Factor -
Article: Hepatic resections for primary liver cancer.
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ABSTRACT: The medical records of 399 patients who underwent hepatic resection between January 1981 and December 1990 were reviewed. Information regarding the results of the hepatic resection in terms of the operative indication, operative procedure, operative morbidity, and mortality was abstracted. As of the end of 1990, a total of 402 hepatic resections had been completed, including those of 319 primary malignancies, 4 secondary malignancies, 2 gallbladder carcinomas, 42 cases of intrahepatic cholelithiasis, and 35 benign masses. Major hepatic resections were performed on 117 patients (29%), of whom 60 (51%) had histologically proven liver cirrhosis. Minor hepatic resections were performed on the remaining 285 patients (71%). Sepsis was the most frequent complication, which manifested primarily as wound infection (71 cases) or intra-abdominal infection (25 cases). Nonfatal hepatic failure occurred in nine patients with cirrhosis and one patient without cirrhosis. There were 38 operative deaths among the 402 hepatic resections, for an overall operative mortality of 9.4%; 25 of those deaths were due to hepatic failure after the operation, accounting for 66% of the total operative mortality. There was an increasing frequency of hepatic resection during the last 5 years. The indication for resection due to hepatocellular carcinoma increased from 87 to 195 cases. The cumulative data show a decrease in the incidence of complications and the operative mortality rate. In the most recent period, nonlethal postoperative complications occurred in 135 of 286 patients (47%). The overall 1-, 3-, and 5-year survival rates for 172 patients, excluding cases of operative mortality, palliative resection, and re-resection, were 71.0%, 39.8%, and 28.3%, respectively.Cancer Chemotherapy and Pharmacology 02/1994; 33 Suppl:S18-23. · 2.83 Impact Factor -
Article: Living donor segmental liver transplantation in dogs.
Transplantation Proceedings 09/1992; 24(4):1611-3. · 1.00 Impact Factor -
Article: KSTAR thermal shield
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ABSTRACT: The thermal shield intercepts thermal radiation from the components at room temperature to superconducting magnet at 4.5 K. The thermal shield of KSTAR is divided into three categories: vacuum vessel thermal shield, port thermal shield, and cryostat thermal shield. Tube-on-panel is the basic configuration of KSTAR thermal shield. The layout of the tubing has been designed to get the temperature distribution of 80 K. The shield is designed to be cooled down by flowing gaseous helium at 18 bar in the tube. After the installation, helium leak test was intensively performed to confirm leak tightness of cooling pipes of which length are about 703 and 2544 m for vacuum vessel thermal shield and cryostat thermal shield, respectively. On April 3, 2008, the cool down of the KSTAR started and during the operation the temperature was monitored by PT-100 temperature sensor. This paper describes the overalls of thermal shield work from design to installation, and reports the results of the KSTAR thermal shield during initial operation.Fusion Engineering and Design. -
Article: Overview of the KSTAR vacuum pumping system
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ABSTRACT: The installation of the Korea Superconducting Tokamak Advanced Research (KSTAR) device vacuum pumping system for both the vacuum vessel and the cryostat was finished in the middle of 2007. After the successful self-commissioning of the main vacuum pumping system by August 2007, the system successfully operated in the integrated system commissioning and 1st plasma experiments of the KSTAR device. The vacuum pumping system has successfully operated and achieved the target vacuum pressure for the vacuum vessel and the cryostat during the machine commissioning and 1st plasma experiments with no severe troubles and problems, which is one of the main factors that led the KSTAR project to achieve successful 1st plasma. Furthermore, the vacuum pumping system has been satisfactorily operated by remote control and synchronization in gas puffing experiments. This paper describes the final configuration of the KSTAR vacuum pumping system, the results of vacuum commissioning, and the other results of the vacuum conditions that relate to wall conditioning.Fusion Engineering and Design.
Top co-authors
Top Journals
Institutions
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2011
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Ulsan University Hospital
Ulsan, Ulsan, South Korea
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2003
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Yonsei University
- Department of Chemistry
Seoul, Seoul, South Korea
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