126 results on '"Hyuck Jae Choi"'
Search Results
2. Effect of iridium oxide as an additive on catalysts with different Pt contents in cell reversal conditions of polymer electrolyte membrane fuel cells
- Author
-
Yong-Hun Cho, Yung-Eun Sung, Oh Joong Kwon, Sungjun Kim, Jong Min Lee, Hyung-Won Shim, Chi-Yeong Ahn, Young-Shik Kim, Hyuck Jae Choi, Sun Young Kang, and Ok-Hee Kim
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,Scanning electron microscope ,Energy Engineering and Power Technology ,chemistry.chemical_element ,Electrolyte ,Condensed Matter Physics ,Corrosion ,Anode ,Catalysis ,Fuel Technology ,Membrane ,chemistry ,Chemical engineering ,Electrode ,Platinum - Abstract
Cell reversal is observed when a current load is applied to the polymer electrolyte membrane fuel cell under fuel starvation conditions. Cell reversal causes severe corrosion (or oxidation) of the carbon support in the anode, which leads to a decrease in overall fuel cell performance. To suppress the corrosion reaction of carbon under cell reversal conditions and to increase the durability of fuel cells, studies on anode additives are being conducted. However, studies on the effect of additives on catalysts with different platinum contents have not been conducted. In this study, 20 wt%, 40 wt%, 60 wt% commercial Pt/C catalyst was applied to the anode, and 50 cycles of cell reversal were performed. Furthermore, the performance change with and without IrO2 as an additive was observed and its effect was assessed. Changes in the morphologies of the electrodes before and after cell reversal tests were also observed using a transmission electron microscope and a scanning electron microscope. The higher the platinum content of the catalyst, the more resistant to cell reversal. In addition, the addition of IrO2 to the anode effectively prevents performance degradation due to cell reversal.
- Published
- 2022
3. Effect of anode iridium oxide content on the electrochemical performance and resistance to cell reversal potential of polymer electrolyte membrane fuel cells
- Author
-
Ok-Hee Kim, Yong-Hun Cho, Yung-Eun Sung, Sun Young Kang, Chi-Yeong Ahn, and Hyuck Jae Choi
- Subjects
Materials science ,Hydrogen ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,Proton exchange membrane fuel cell ,chemistry.chemical_element ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrochemistry ,01 natural sciences ,Cathode ,0104 chemical sciences ,Anode ,law.invention ,Fuel Technology ,Membrane ,Chemical engineering ,chemistry ,law ,Electrode ,0210 nano-technology - Abstract
An ideal polymer electrolyte membrane fuel cell (PEMFC) is one that continuously generates electricity as long as hydrogen and oxygen (or air) are supplied to its anode and cathode, respectively. However, internal and/or external conditions could bring about the degradation of its electrodes, which are composed of nanoparticle catalysts. Particularly, when the hydrogen supply to the anode is disrupted, a reverse voltage is generated. This phenomenon, which seriously degrades the anode catalyst, is referred to as cell reversal. To prevent its occurrence, iridium oxide (IrO2) particles were added to the anode in the membrane-electrode assembly of the PEMFC single-cells. After 100 cell reversal cycles, the single-cell voltage profiles of the anode with Pt/C only and the anodes with Pt/C and various IrO2 contents were obtained. Additionally, the cell reversal-induced degradation phenomenon was also confirmed electrochemically and physically, and the use of anodes with various IrO2 contents was also discussed.
- Published
- 2021
4. MGMT Promoter Methylation Status in Initial and Recurrent Glioblastoma: Correlation Study with DWI and DSC PWI Features
- Author
-
Seung Hong Choi, Chul-Kee Park, Roh-Eul Yoo, Hyuck Jae Choi, Sung Hye You, Koung Mi Kang, Tae Jin Yun, Chul-Ho Sohn, Sung Hye Park, and Ji Hoon Kim
- Subjects
Oncology ,medicine.medical_specialty ,Methyltransferase ,Receiver operating characteristic ,business.industry ,Adult Brain ,Standard treatment ,Methylation ,030218 nuclear medicine & medical imaging ,Correlation ,03 medical and health sciences ,0302 clinical medicine ,Text mining ,Internal medicine ,medicine ,Mann–Whitney U test ,Radiology, Nuclear Medicine and imaging ,Neurology (clinical) ,Analysis of variance ,business ,neoplasms ,030217 neurology & neurosurgery - Abstract
BACKGROUND AND PURPOSE: O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status in primary and recurrent glioblastoma may change during treatment. The purpose of this study was to correlate MGMT promoter methylation status changes with DWI and DSC PWI features in patients with recurrent glioblastoma after standard treatment. MATERIALS AND METHODS: Between January 2008 and November 2016, forty patients with histologically confirmed recurrent glioblastoma were enrolled. Patients were divided into 3 groups according to the MGMT promoter methylation status for the initial and recurrent tumors: 2 groups whose MGMT promoter methylation status remained, group methylated (n = 13) or group unmethylated (n = 18), and 1 group whose MGMT promoter methylation status changed from methylated to unmethylated (n = 9). Normalized ADC and normalized relative CBV values were obtained from both the enhancing and nonenhancing regions, from which histogram parameters were calculated. The ANOVA and the Kruskal-Wallis test followed by post hoc tests were performed to compare histogram parameters among the 3 groups. The t test and Mann-Whitney U test were used to compare parameters between group methylated and group methylated to unmethylated. Receiver operating characteristic curve analysis was used to measure the predictive performance of the normalized relative CBV values between the 2 groups. RESULTS: Group methylated to unmethylated showed significantly higher means and 90th and 95th percentiles of the cumulative normalized relative CBV values of the nonenhancing region of the initial tumor than group methylated and group unmethylated (all P < .05). The mean normalized relative CBV value of the nonenhancing region of the initial tumor was the best predictor of methylation status change (P < .001), with a sensitivity of 77.78% and specificity of 92.31% at a cutoff value of 2.594. CONCLUSIONS: MGMT promoter methylation status might change in recurrent glioblastoma after standard treatment. The normalized relative CBV values of the nonenhancing region at the first preoperative MR imaging were higher in the MGMT promoter methylation change group from methylation to unmethylation in recurrent glioblastoma.
- Published
- 2021
5. From Half‐Cells to Membrane‐Electrode Assemblies: a Comparison of Oxygen Reduction Reaction Catalyst Performance Characteristics
- Author
-
Yong-Hun Cho, Yung-Eun Sung, Hyuck Jae Choi, Sun-Whe Kim, C.‐Y. Ahn, Ok-Hee Kim, and Sang-Uk Kang
- Subjects
Membrane ,Materials science ,Chemical engineering ,Renewable Energy, Sustainability and the Environment ,Membrane electrode assembly ,Electrode ,Energy Engineering and Power Technology ,Oxygen reduction reaction ,Electrocatalyst ,Electrochemistry ,Half-cell ,Catalysis - Published
- 2019
6. Effects of Short-term Acute Heat Stress on Physiological Responses and Heat Shock Proteins of Hanwoo Steer (Korean Cattle)
- Author
-
Sung-Dae Lee, Jin Young Jeong, Hyuck Jae Choi, Youl-Chang Baek, Min-Seok Kim, Yookyung Lee, Sang Yun Ji, and Young-Kyoon Oh
- Subjects
lcsh:R5-920 ,lcsh:Internal medicine ,blood parameter ,Rump ,Chemistry ,lcsh:Biotechnology ,heat shock protein ,Physiological responses ,Heat stress ,heat stress ,Animal science ,lcsh:TP248.13-248.65 ,Heat shock protein ,Air temperature ,Hanwoo ,Respiration ,respiration rate ,lcsh:Medicine (General) ,lcsh:RC31-1245 ,Respiration rate ,body temperature - Abstract
This study was performed to evaluate the effect of heat stress on the status of physiological responses, blood parameter, serum T3 and cortisol, and heat shock proteins (HSP 27, 70, and 90) of Hanwoo cattle. Six Hanwoo steers (242.8 ± 7.2 kg of BW) were housed in the climate-controlled respiration chambers. The experiment consisted of 7 days (control; 0 day) at thermoneutral (air temperature (Ta) of 15°C and relative humidity (RH) of 60%; temperature-humidity index (THI) = 64), and by 3 and 6 days (treatment groups) at heat stress (Ta of 35°C and RH of 60%; THI = 87). Body temperature of each parts (frank, rump, perineum and foot) and rectal temperature elevated in heat stress groups (3 days and 6 days) than the control group (0 day). Respiration rates increased in 3 days and 6 days (88.5 ± 0.96 bpm and 86.3 ± 0.63 bpm, respectively) from 0 days (39.5 ± 0.65 bpm). Feed intake significantly decreased in heat stress groups (3 days and 6 days, 3.7 ± 0.14 kg and 4.0 ± 0.15 kg, respectively) than the control group (0 day, 5.0 ± 0.00 kg). In addition, final BW significantly decreased in heat stress groups (3 days and 6 days, 211.8 ± 4.75 kg and 215.5 ± 3.50 kg, respectively) than the control group (0 day, 240.0 ± 25.00 kg). However, heat stress has no significant effect on blood parameter, serum T3 and cortisol. Nevertheless, heat stress increased HSPs mRNA expression in liver tissue, and serum concentration of HSPs. Despite Hanwoo cattle may have high adaptive ability to heat stress, our results suggested that heat stress directly effect on body temperature and respiration rate as well as serum and tissue HSPs. Therefore, we are recommended that HSPs could be the most appropriate indicators of Hanwoo cattle response to heat stress.
- Published
- 2019
7. Low-Tube-Voltage CT Urography Using Low-Concentration-Iodine Contrast Media and Iterative Reconstruction: A Multi-Institutional Randomized Controlled Trial for Comparison with Conventional CT Urography
- Author
-
Chan Kyo Kim, Sung Bin Park, You Me Kim, Sung Il Hwang, Min Hoan Moon, Deuk Jae Sung, Eun Ju Lee, Joongyub Lee, Sung Eun Rha, Sang Youn Kim, Sung Il Jung, Yongsoo Kim, Youngsup Shim, Jeong Yeon Cho, Hyun Lee, Seong Sook Hong, Hyuck Jae Choi, Sungmin Woo, Kyeong Ah Kim, Dong Won Kim, and Inpyeong Hwang
- Subjects
Adult ,Male ,Image quality ,media_common.quotation_subject ,chemistry.chemical_element ,Computed tomography ,Iterative reconstruction ,Ct urography ,Signal-To-Noise Ratio ,Iodine ,030218 nuclear medicine & medical imaging ,law.invention ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Randomized controlled trial ,Double dose reduction ,law ,Image Interpretation, Computer-Assisted ,Medicine ,Contrast (vision) ,Humans ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Urinary Tract ,media_common ,Aged ,medicine.diagnostic_test ,business.industry ,Contrast media ,Low tube voltage ,Urography ,Middle Aged ,Low dose ,chemistry ,Genitourinary Imaging ,030220 oncology & carcinogenesis ,Original Article ,Female ,business ,Nuclear medicine ,Tomography, X-Ray Computed - Abstract
Objective To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU. Materials and methods This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated. Results The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose (5.73 ± 4.04 vs. 8.43 ± 4.38 mSv) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ≥ 3), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group. Conclusion The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.
- Published
- 2018
8. In situ Ruminal and Intestinal Digestibility of Crude Protein and Amino Acids in By-product Feedstuffs
- Author
-
Jin Young Jeong, Do Hyung Kim, Hyuck Jae Choi, Youl Chang Baek, Young Kyoon Oh, Hyun Jung Jung, Hyun Jung Lee, and Min-Seok Kim
- Subjects
In situ ,chemistry.chemical_classification ,chemistry ,By-product ,Food science ,Amino acid - Published
- 2018
9. Metal-free, Brønsted acid-mediated synthesis of coumarin derivatives from phenols and propiolic acids
- Author
-
Hyuck Jae Choi, Kooyeon Lee, and Jaehyun Kim
- Subjects
010405 organic chemistry ,Organic Chemistry ,Intramolecular cyclization ,010402 general chemistry ,Coumarin ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Metal ,chemistry.chemical_compound ,Metal free ,chemistry ,visual_art ,Drug Discovery ,Rapid access ,visual_art.visual_art_medium ,Organic chemistry ,heterocyclic compounds ,Phenols ,Brønsted–Lowry acid–base theory - Abstract
A novel synthesis of coumarin derivatives by Bronsted acid-mediated condensation and intramolecular cyclization of phenols and propiolic acids was reported. This transformation requires the use of TfOH in place of a conventional metal mediator, and it occurs under mild conditions and provides rapid access to coumarin derivatives in good yields.
- Published
- 2016
10. Bismuth-catalyzed synthesis of anthracenes via cycloisomerization of o-alkynyldiarylmethane
- Author
-
Kooyeon Lee, Deug-Chan Lee, Jungmin Park, and Hyuck Jae Choi
- Subjects
Anthracene ,chemistry.chemical_compound ,Cycloisomerization ,chemistry ,Organic Chemistry ,Drug Discovery ,Trifluoroacetic acid ,chemistry.chemical_element ,Organic chemistry ,Brønsted–Lowry acid–base theory ,Biochemistry ,Catalysis ,Bismuth - Abstract
In this study, anthracenes were efficiently synthesized from o -alkynyldiarylmethane using a novel method that exploits the synergistic effect between Bi(OTf) 3 as the catalyst, and trifluoroacetic acid (TFA). Through this reaction, we achieved the rapid and efficient synthesis of anthracenes bearing various functional groups under mild conditions.
- Published
- 2015
11. The Value of Preoperative Positron Emission Tomography/Computed Tomography in Node-Negative Endometrial Cancer on Magnetic Resonance Imaging
- Author
-
Jong Jin Lee, Hye Ok Kim, Sun-Young Chae, Young-Tak Kim, In Hye Song, Joo-Hyun Nam, Jeong-Yeol Park, Hyuck Jae Choi, and Chang Ohk Sung
- Subjects
Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Preoperative care ,030218 nuclear medicine & medical imaging ,Metastasis ,03 medical and health sciences ,0302 clinical medicine ,Fluorodeoxyglucose F18 ,Positron Emission Tomography Computed Tomography ,Preoperative Care ,medicine ,Humans ,Survival rate ,Lymph node ,medicine.diagnostic_test ,business.industry ,Endometrial cancer ,Magnetic resonance imaging ,Middle Aged ,medicine.disease ,Prognosis ,Adenocarcinoma, Mucinous ,Magnetic Resonance Imaging ,Cystadenocarcinoma, Serous ,Endometrial Neoplasms ,Survival Rate ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Lymphatic Metastasis ,Lymph Node Excision ,Surgery ,Lymphadenectomy ,Female ,Radiology ,Lymph ,Lymph Nodes ,Radiopharmaceuticals ,Nuclear medicine ,business ,Adenocarcinoma, Clear Cell ,Follow-Up Studies - Abstract
The aim of this study was to investigate the value of [18F]fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in predicting lymph node status in node-negative endometrial cancer on preoperative magnetic resonance imaging (MRI). Patients with endometrial cancer who underwent both preoperative MRI and FDG-PET/CT followed by hysterectomy and lymphadenectomy were initially included. We then enrolled patients with MRI-defined node-negative disease (lymph nodes
- Published
- 2017
12. A Case of Post-radiotherapy Urethral Stricture with Spontaneous Bladder Rupture, Mimicking Obstructive Uropathy due to Cancer Metastasis
- Author
-
Woo Chul Joo, Sang Min Yoon, Si Nae Lee, Moon-Jae Kim, Jun Young Shin, Seoung Woo Lee, Hai Bong Kim, Joon Ho Song, and Hyuck Jae Choi
- Subjects
medicine.medical_specialty ,Physiology ,Urethral stricture ,Urology ,Case Report ,Hydronephrosis ,urologic and male genital diseases ,Spontaneous rupture ,Cystography ,Internal Medicine ,medicine ,Obstructive uropathy ,Urinary bladder ,Spontaneous Bladder Rupture ,medicine.diagnostic_test ,Radiotherapy ,business.industry ,Acute kidney injury ,Cystoscopy ,medicine.disease ,medicine.anatomical_structure ,Cardiology and Cardiovascular Medicine ,business - Abstract
Non-traumatic, spontaneous urinary bladder rupture is a rare complication of urethral stricture. Furthermore, its symptoms are often nonspecific, and misdiagnosis is common. The authors experienced a case of urethral stricture with spontaneous bladder rupture and bilateral hydronephrosis, mimicking obstructive uropathy attributed to cancer metastasis. A 55-year-old woman was admitted with abdominal pain and distension, oliguria, and an elevated serum creatinine level. She had undergone radical hysterectomy for uterine cervical cancer and received post-operative concurrent chemoradiation therapy 13 years previously. Non-contrast enhanced computed tomography showed massive ascites and bilateral hydronephrosis. The initial diagnosis was acute kidney injury due to obstructive uropathy caused by malignant disease. After improvement of her renal function by bilateral percutaneous nephrostomy catheterization, contrast-enhanced computed tomography and a cytologic examination of ascites showed no evidence of malignancy. However, during retrograde pyelography, a severe urethral stricture was found, and subsequent cystography showed leakage of contrast into the peritoneal cavity and cystoscopy revealed a defect of the posterior bladder wall. After urethral dilatation and primary closure of the bladder wall, acute kidney injury and ascites were resolved.
- Published
- 2014
13. Three-phase, contrast-enhanced, multidetector CT in the evaluation of complicated renal cysts: comparison of the postcontrast phase combination
- Author
-
Hyuck Jae Choi, Mi-Hyun Kim, Rang Yi, and Kyoung-Sik Cho
- Subjects
Adult ,Male ,medicine.medical_specialty ,Contrast Media ,Diagnostic accuracy ,Multidetector ct ,Sensitivity and Specificity ,Predictive Value of Tests ,Multidetector Computed Tomography ,Multidetector computed tomography ,medicine ,Humans ,Optimal combination ,Radiology, Nuclear Medicine and imaging ,Aged ,Retrospective Studies ,Aged, 80 and over ,Kidney ,Radiological and Ultrasound Technology ,business.industry ,General Medicine ,Kidney Diseases, Cystic ,Middle Aged ,medicine.anatomical_structure ,Renal cysts ,Female ,Radiology ,business - Abstract
Background Multiphasic multidetector computed tomography (MDCT) is widely used for the assessment and diagnosis of complicated renal cysts. Purpose To determine the optimal combination of postcontrast phases of MDCT for the evaluation of complicated renal cysts. Material and Methods In 164 renal cysts with pathology confirmation or follow-up >2 years, the Bosniak category was recorded by two radiologists in consensus. They reviewed the MDCT images during three interpretation sessions. In the first session, the radiologists evaluated two phases of images (unenhanced and corticomedullary phases), while during the second session, they evaluated two phases of images (unenhanced and parenchymal phases), and in the third session, they evaluated all three phases of images (unenhanced, corticomedullary, and parenchymal phases). The diagnostic accuracy for evaluating renal cysts was compared in each session using receiver-operating characteristics (ROC) analysis. Results There were 106 benign renal cysts and 58 malignant renal cysts. The areas under the ROC curves (AUCs) of the second and third sessions were greater than that of the first session ( P Conclusion Unenhanced and parenchymal phase CT scans are sufficient for differentiating malignant from benign renal cysts and there was no additional value by adding the corticomedullary phase to the combination of unenhanced and parenchymal phase CT.
- Published
- 2014
14. Comparison of T2-Weighted MRI With and Without Fat Suppression for Differentiating Renal Angiomyolipomas Without Visible Fat From Other Renal Tumors
- Author
-
Hyuck Jae Choi, Kyoung-Sik Cho, Mi-Hyun Kim, and Mi Sun Chung
- Subjects
Adult ,Male ,Pathology ,medicine.medical_specialty ,Angiomyolipoma ,Adolescent ,Fat suppression ,Sensitivity and Specificity ,Diagnosis, Differential ,Predictive Value of Tests ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Aged ,Retrospective Studies ,medicine.diagnostic_test ,Receiver operating characteristic ,business.industry ,Subtraction ,Kidney Neoplasm ,Magnetic resonance imaging ,General Medicine ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Kidney Neoplasms ,Adipose Tissue ,Predictive value of tests ,Female ,Nuclear medicine ,business ,T2 weighted - Abstract
The purpose of this study was to retrospectively compare the usefulness of T2-weighted imaging with and without fat suppression for differentiating angiomyolipomas (AMLs) without visible fat from other renal tumors.MRI was performed in 111 patients (66 men and 46 women; age range, 17-78 years) who had pathologically diagnosed (14 AMLs, 86 renal cell carcinomas [RCCs], and three other tumors) and clinically diagnosed (eight AMLs) renal masses without visible fat or a cystic portion on unenhanced CT. The signal intensity (SI), tumor-to-kidney SI ratio, tumor-to-spleen SI ratio on T2-weighted imaging and fat-suppressed T2-weighted imaging, and tumor-fat subtraction index were measured for each tumor. Receiver operating characteristic (ROC) analysis was used to evaluate diagnostic accuracy of SI ratios.The highest area under the ROC curve was 0.886 for tumor-to-kidney SI ratio on fat-suppressed T2-weighted imaging. With a tumor-to-kidney SI ratio of 0.9 on fat-suppressed T2-weighted imaging, the sensitivity, specificity, positive predictive value, and negative predictive value were 90.9%, 71.1%, 43.5%, and 97%, respectively. The highest tumor-to-kidney SI ratio of AMLs without visible fat was 1.09. Ninety-eight percent of renal tumors with a tumor-to-kidney SI ratio greater than 1.09 were RCCs (51/52), especially clear cell RCCs (82.7%, 43/52).Fat-suppressed T2-weighted imaging is more useful than T2-weighted imaging for differentiating AMLs without visible fat from non-AMLs. The high SI of solid renal masses on fat-suppressed T2-weighted imaging can be indicative of non-AMLs, especially RCCs.
- Published
- 2014
15. Aberrant DNA methylation in the IFITM1 promoter enhances the metastatic phenotype in an intraperitoneal xenograft model of human ovarian cancer
- Author
-
Woong Ju, Jung Hyuck Ahn, Eun Nam Choi, Nam Hee Kim, Hye Youn Sung, Hyuck Jae Choi, and Dahyun Lyu
- Subjects
Cancer Research ,Biology ,Decitabine ,medicine.disease_cause ,Metastasis ,Mice ,chemistry.chemical_compound ,Cell Line, Tumor ,Ovarian carcinoma ,Biomarkers, Tumor ,medicine ,Animals ,Humans ,Epigenetics ,Neoplasm Metastasis ,Promoter Regions, Genetic ,Ovarian Neoplasms ,Mice, Inbred BALB C ,Ovary ,Cancer ,General Medicine ,DNA Methylation ,medicine.disease ,Antigens, Differentiation ,Xenograft Model Antitumor Assays ,Demethylating agent ,Oncology ,chemistry ,DNA methylation ,Azacitidine ,Cancer research ,Female ,Ovarian cancer ,Carcinogenesis ,Injections, Intraperitoneal - Abstract
A lack of reliable biomarkers for the early detection and risk of metastatic recurrences makes ovarian cancer the most lethal gynecological cancer. To understand the molecular mechanisms involved in ovarian cancer metastasis in vivo, we analyzed the transcriptional expression pattern in metastatic implants of human ovarian carcinoma xenografts in mice. The expression of 937 genes was significantly different, by at least 2-fold, in the xenografts compared with that in SK-OV-3 cells. We investigated the mechanisms that regulate the expression of one of the profoundly upregulated genes, interferon-induced transmembrane protein 1 (IFITM1), in the metastatic implants. Specific CpG sites within the IFITM1 promoter were hypomethylated in the metastatic implants relative to those in the wild-type SK-OV-3 cells. Treating wild-type SK-OV-3 cells with the demethylating agent 5-aza-2'-deoxycytidine enhanced IFITM1 expression in a dose-dependent manner, implying transcriptional regulation by promoter methylation. We also found that IFITM1 overexpression caused increased migration and invasiveness in SK-OV-3 cells. Our results demonstrate that IFITM1 could be a novel metastasis-promoting gene that enhances the metastatic phenotype in ovarian cancer via epigenetic transcriptional regulation. Our findings also suggest that the status of DNA methylation within the IFITM1 promoter region could be a biomarker indicating metastatic progression in ovarian cancer.
- Published
- 2014
16. Synthesis of water well-dispersed PEGylated iron oxide nanoparticles for MR/optical lymph node imaging
- Author
-
Yuanzhe Piao, Hyuck Jae Choi, Hong-Il Cho, and Kyung Mo Yang
- Subjects
Materials science ,Reducing agent ,Biomedical Engineering ,General Chemistry ,General Medicine ,Polyethylene glycol ,Solvent ,chemistry.chemical_compound ,Colloid ,chemistry ,PEG ratio ,Organic chemistry ,Surface modification ,General Materials Science ,Iron oxide nanoparticles ,Preclinical imaging ,Nuclear chemistry - Abstract
We reported the synthesis of highly water-stable iron oxide nanoparticles by a simple one-pot reaction. Non-toxic polyethylene glycol MW 600 (PEG) acted as a solvent, capping agent and reducing agent in the synthesis of iron oxide nanoparticles. As a result of the synthesis, PEGylated small-size (4.2 ± 0.39 nm average diameter and 7.2 ± 1.9 nm hydrodynamic sizes measuring by DLS) iron oxide nanoparticles (USPIO) were obtained, which show great colloidal stability in water and tolerate high salt concentration (0.75 M sodium chloride) and a wide pH range of 4 to 12. Oxidation of PEG was observed during the synthesis of iron oxide nanoparticles, which makes USPIO easy to functionalize with other molecules. Functionalization of the USPIO surface with fluorescein isothiocyanate (FITC) was conducted for investigating the possibility for multimodal imaging. Also the cytotoxicity test and lymph node imaging were performed by using the FITC labelled USPIO (FITC@USPIO). According to these results, the stable water dispersed USPIO and FITC@USPIO are expected to apply for multimodal in vivo imaging.
- Published
- 2014
17. Diagnostic Performance of Multidetector Computed Tomography in the Evaluation of Perinephric Fat Invasion in Renal Cell Carcinoma Patients
- Author
-
Cherry Kim, Kyoung-Sik Cho, and Hyuck Jae Choi
- Subjects
Adult ,Male ,medicine.medical_specialty ,Adolescent ,Contrast Media ,Iopamidol ,Adipose capsule of kidney ,Renal cell carcinoma ,Multidetector Computed Tomography ,Multidetector computed tomography ,Carcinoma ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Carcinoma, Renal Cell ,Aged ,Neoplasm Staging ,Aged, 80 and over ,Tumor size ,business.industry ,Area under the curve ,Middle Aged ,medicine.disease ,Kidney Neoplasms ,Adipose Tissue ,Coronal plane ,Female ,Radiology ,business ,medicine.drug - Abstract
Purpose This study aimed to evaluate the diagnostic performance of multidetector computed tomography (MDCT) for preoperative evaluation of perinephric fat invasion in patients with renal cell carcinomas (RCCs). Methods A total of 408 consecutive patients with surgically confirmed RCC who underwent MDCT were included in this study. Image analysis was first performed with axial-only CT images. A second analysis was then performed with both axial and coronal CT images. A qualitative analysis was then conducted by 2 reviewers who reached consensus. The reference standard was pathologic evaluation. Results The areas under the curve of the receiver operating characteristic analysis were 0.786 and 0.877 for axial-only images and 0.805 and 0.836 for combined images in both readers. The area under the curve of tumor size was 0.833, a similar value to that of the reviewers. In multivariate analysis, tumor size, a linear-nodular or nodular type of fat infiltration, and an irregular tumor margin were independent predicting factors for perinephric fat invasion. Conclusions The MDCT shows relatively high diagnostic performance in detecting perinephric fat invasion of RCC, but suffers from a relatively low positive predictive value. Tumor size, fat infiltration with a nodular appearance, and an irregular tumor margin were predictors for perinephric invasion.
- Published
- 2014
18. FP384EFFECT OF OMEGA-3 FATTY ACID AND MENAQUINONE-7 ON OSTEOPENIA AND SARCOPENIA IN ADENINE AND LOW PROTEIN DIET INDUCED UREMIC RATS
- Author
-
Sung Hyun Son, Eu Gene Jeong, Su Mi Lee, Hyuck Jae Choi, Young Ki Son, Won Suk An, and Seong Eun Kim
- Subjects
Transplantation ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,medicine.disease ,Osteopenia ,Endocrinology ,Low-protein diet ,Nephrology ,Sarcopenia ,Internal medicine ,medicine ,Omega 3 fatty acid ,business - Published
- 2018
19. Terahertz spectroscopic imaging of a rabbit VX2 hepatoma model.
- Author
-
Jae Yeon Park, Hyuck Jae Choi, Kyoung-Sik Cho, Kyu-Rae Kim, and Joo-Hiuk Son
- Subjects
- *
TERAHERTZ spectroscopy , *LIVER cancer , *RABBITS , *DIAGNOSTIC imaging , *LIVER tumors - Abstract
Terahertz (THz) spectroscopic imaging technique was applied to classify the tumor region in the rabbit liver with VX2 hepatocellular carcinoma. Within the measurement range of 0.1-2 THz, the average reflectance values for all tumor samples were more than 4% higher than those for healthy cells, and the terahertz measurements correlated well with histological analysis results. This study on paraffin-embedded tissues showed the alteration of cell density and protein content in tumors, excluding the effect of water. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
20. Response Evaluation Criteria in Solid Tumors Response of the Primary Lesion in Metastatic Renal Cell Carcinomas Treated With Sunitinib: Does the Primary Lesion Have to Be Regarded as a Target Lesion?
- Author
-
Jae-Lyun Lee, Kwonoh Park, Yongcheol Ahn, Jin-Hee Ahn, Hyuck Jae Choi, Hanjong Ahn, Jun Hyuk Hong, Choung-Soo Kim, Seong Joon Park, Inkeun Park, In Gab Jeong, and Cheryn Song
- Subjects
Adult ,Male ,Target lesion ,medicine.medical_specialty ,Indoles ,Survival ,Urology ,Cell ,Best Overall Response ,Angiogenesis Inhibitors ,Kidney ,Nephrectomy ,Stable Disease ,Sunitinib ,medicine ,Humans ,Pyrroles ,Neoplasm Metastasis ,Carcinoma, Renal Cell ,Aged ,Retrospective Studies ,business.industry ,Middle Aged ,Primary lesion ,medicine.disease ,Primary tumor ,Kidney Neoplasms ,Treatment Outcome ,medicine.anatomical_structure ,Oncology ,Response Evaluation Criteria in Solid Tumors ,Female ,Radiology ,business ,medicine.drug - Abstract
Background We evaluated whether best overall response changes by designating primary renal lesions as either target or nontarget lesions and assessing response per Response Evaluation Criteria in Solid Tumors in mRCC patients treated with sunitinib. In addition, we evaluated whether discordance, if any, leads to a difference in predictive value of response in terms of time to progression (TTP) and overall survival (OS). Patients and Methods Patients with mRCC with an intact primary tumor and at least 1 extrarenal measurable lesion were included in this study. The variation of the sum of diameters (ΔSOD) of target lesions and best overall response, assessed from all target lesions and from metastasis-only target lesions, was documented separately. Results There were 41 patients included. Median ΔSOD of the primary lesion and metastatic target lesion were −6.0% (range, −34.0% to 17.6%), and −18.0% (range, −100.0% to 120.0%), respectively. For metastasis-only target lesions, the best overall response of 2 patients (4.9%) changed from stable disease to partial response. When we categorized patients into responders and nonresponders, response determination using metastasis-only target lesions resulted in significantly better discrimination of time to progression (14.9 vs. 4.3 months, P = .001) and overall survival (18.5 vs. 9.6 months, P = .036) between 2 groups. Using all target lesions, both TTP (14.9 vs. 5.4 months, P = .056) and OS (18.0 vs. 10.6 months, P = .155) were not statistically significant. Conclusion When treating nonnephrectomized mRCC patients, selecting metastasis-only lesions as target lesions might be better to determine response, which might be more representative of survival end point.
- Published
- 2013
21. Synthesis of Monodisperse Hollow Carbon Nanocapsules by Using Protective Silica Shells
- Author
-
Bo Quan, Gi-Eun Nam, Hyuck Jae Choi, and Yuanzhe Piao
- Subjects
Nanostructure ,Cell Survival ,Dispersity ,Octadecyltrimethoxysilane ,Nanoparticle ,Ibuprofen ,Nanotechnology ,Biochemistry ,Nanocapsules ,Polyethylene Glycols ,law.invention ,chemistry.chemical_compound ,Dynamic light scattering ,law ,Cell Line, Tumor ,Humans ,Calcination ,Particle Size ,Drug Carriers ,Anti-Inflammatory Agents, Non-Steroidal ,Organic Chemistry ,Temperature ,Water ,General Chemistry ,Silanes ,Silicon Dioxide ,Carbon ,chemistry ,Chemical engineering ,Mesoporous material ,Porosity - Abstract
Monodisperse hollow carbon nanocapsules (200 nm) with mesoporous shells were synthesized by coating their outer shells with silica to prevent aggregation during their high-temperature annealing. Monodispersed silica nanoparticles were used as starting materials and octadecyltrimethoxysilane (C18TMS) was used as a carbon source to create core-shell nanostructures. These core-shell nanoparticles were coated with silica on their outer shell to form a second shell layer. This outer silica shell prevented aggregation during calcination. The samples were characterized by TEM, SEM, dynamic light scattering (DLS), UV/Vis spectroscopy, and by using the Brunauer-Emmett-Teller (BET) method. The as-synthesized hollow carbon nanoparticles exhibited a high surface area (1123 m(2) g(-1)) and formed stable dispersions in water after the pegylation process. The drug-loading and drug-release properties of these hollow carbon nanocapsules were also investigated.
- Published
- 2013
22. Additional Value of Combined Evaluation of Tumor Size With Lymph Node Size in the Detection of Lymph Node Metastases in Early-Stage Cervical Cancer Patients
- Author
-
Sunji Kang, Hyuck Jae Choi, Young Seok Kim, Kyung-Sik Cho, and Mi-Hyun Kim
- Subjects
Adult ,Oncology ,medicine.medical_specialty ,medicine.medical_treatment ,Uterine Cervical Neoplasms ,Sensitivity and Specificity ,Young Adult ,Risk Factors ,Internal medicine ,Republic of Korea ,Prevalence ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Stage (cooking) ,Lymph node ,Aged ,Neoplasm Staging ,Aged, 80 and over ,Cervical cancer ,medicine.diagnostic_test ,Receiver operating characteristic ,business.industry ,Carcinoma ,Reproducibility of Results ,Magnetic resonance imaging ,Organ Size ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Tumor Burden ,medicine.anatomical_structure ,Lymphatic Metastasis ,Female ,Lymphadenectomy ,Lymph Nodes ,Lymph ,Radiology ,business - Abstract
Although tumor size is a prognostic factor in cervical cancer patients, its role in the diagnosis of lymph node metastasis is unclear. We therefore evaluated the diagnostic value of tumor and lymph node size compared with lymph node size alone in the detection of metastatic lymph nodes in patients with early-stage cervical cancer.We retrospectively evaluated 699 patients with International Federation of Obstetrics and Gynecology stage IB1-IIA cervical carcinoma who underwent magnetic resonance imaging before lymphadenectomy involving all visible lymph nodes in the surgical fields. Seven nodal groups were evaluated: para-aortic, both common iliac, both external iliac, and both internal/obturator areas. Pathologic evaluation was the diagnostic standard. The largest short-axis diameter of lymph nodes in each region and the largest tumor diameters were measured in magnetic resonance images. The value of additional information from magnetic resonance images was evaluated by receiver operating characteristic curve analysis.Of the 699 patients, 108 (15.8%) had lymph node metastases. The areas under the curve for measurements of lymph node size, tumor size, and both were (A) 0.635, (B) 0.706, and (C) 0.742, respectively (A vs B, P = 0.006; A vs C P < 0.001; B vs C, P = 0.002).This study illustrates that magnetic resonance imaging measurements of tumor size and tumor size plus lymph node size showed a higher diagnostic performance than lymph node size alone in predicting lymph node metastasis in patients with early-stage cervical cancer.
- Published
- 2013
23. ChemInform Abstract: Metal-Free, Broensted Acid-Mediated Synthesis of Coumarin Derivatives from Phenols and Propiolic Acids
- Author
-
Kooyeon Lee, Hyuck Jae Choi, and Jaehyun Kim
- Subjects
chemistry.chemical_compound ,Metal free ,Chemistry ,Organic chemistry ,General Medicine ,Phenols ,Coumarin - Published
- 2016
24. Urothelial Tumors
- Author
-
Hyuck Jae Choi, Kyung Chul Moon, Jin Ho Kim, and Ja Hyeon Ku
- Published
- 2016
25. ChemInform Abstract: Bismuth-Catalyzed Synthesis of Anthracenes via Cycloisomerization of O-Alkynyldiarylmethane
- Author
-
Hyuck Jae Choi, Deug-Chan Lee, Kooyeon Lee, and Jungmin Park
- Subjects
chemistry.chemical_compound ,Cycloisomerization ,chemistry ,Trifluoroacetic acid ,chemistry.chemical_element ,General Medicine ,Combinatorial chemistry ,Catalysis ,Bismuth - Abstract
In this study, anthracenes were efficiently synthesized from o -alkynyldiarylmethane using a novel method that exploits the synergistic effect between Bi(OTf) 3 as the catalyst, and trifluoroacetic acid (TFA). Through this reaction, we achieved the rapid and efficient synthesis of anthracenes bearing various functional groups under mild conditions.
- Published
- 2016
26. In vivo magnetic resonance and fluorescence dual imaging of tumor sites by using dye-doped silica-coated iron oxide nanoparticles
- Author
-
Chaedong Lee, Yuanzhe Piao, Haeyun Jang, Gi Eun Nam, Jung Sun Yoo, Hyuck Jae Choi, and Bo Quan
- Subjects
Fluorescence-lifetime imaging microscopy ,Materials science ,Iron oxide ,Nanoparticle ,Bioengineering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Fluorescence ,Atomic and Molecular Physics, and Optics ,Imaging phantom ,0104 chemical sciences ,chemistry.chemical_compound ,Nuclear magnetic resonance ,chemistry ,Modeling and Simulation ,Rhodamine B ,Magnetic nanoparticles ,General Materials Science ,0210 nano-technology ,Iron oxide nanoparticles ,Biomedical engineering - Abstract
The difficulty in delineating tumor is a major obstacle for better outcomes in cancer treatment of patients. The use of single-imaging modality is often limited by inadequate sensitivity and resolution. Here, we present the synthesis and the use of monodisperse iron oxide nanoparticles coated with fluorescent silica nano-shells for fluorescence and magnetic resonance dual imaging of tumor. The as-synthesized core–shell nanoparticles were designed to improve the accuracy of diagnosis via simultaneous tumor imaging with dual imaging modalities by a single injection of contrast agent. The iron oxide nanocrystals (~11 nm) were coated with Rhodamine B isothiocyanate-doped silica shells via reverse microemulsion method. Then, the core–shell nanoparticles (~54 nm) were analyzed to confirm their size distribution by transmission electron microscopy and dynamic laser scattering. Photoluminescence spectroscopy was used to characterize the fluorescent property of the dye-doped silica shell-coated nanoparticles. The cellular compatibility of the as-prepared nanoparticles was confirmed by a trypan blue dye exclusion assay and the potential as a dual-imaging contrast agent was verified by in vivo fluorescence and magnetic resonance imaging. The experimental results show that the uniform-sized core–shell nanoparticles are highly water dispersible and the cellular toxicity of the nanoparticles is negligible. In vivo fluorescence imaging demonstrates the capability of the developed nanoparticles to selectively target tumors by the enhanced permeability and retention effects and ex vivo tissue analysis was corroborated this. Through in vitro phantom test, the core/shell nanoparticles showed a T2 relaxation time comparable to Feridex® with smaller size, indicating that the as-made nanoparticles are suitable for imaging tumor. This new dual-modality-nanoparticle approach has promised for enabling more accurate tumor imaging.
- Published
- 2016
27. Sonography of the adrenal glands in the adult
- Author
-
Kyoung-Sik Cho, Jeongjin Lee, Jeong Kon Kim, Hyuck Jae Choi, Mi-Hyun Kim, and Kyoung Won Kim
- Subjects
Adult ,medicine.medical_specialty ,Pathology ,business.industry ,Adrenal gland ,Adrenal Gland Diseases ,Patient positioning ,Patient Positioning ,medicine.anatomical_structure ,Adrenal Glands ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Screening tool ,Adrenal lesion ,Radiology ,business ,Adrenal tumors ,Ultrasonography - Abstract
Although its capability has been overlooked, sonography can be a useful screening tool for adrenal lesion in adults. In this article, we discuss scan technique, patient positioning, and anatomic consideration for adrenal sonography in adults and illustrate sonographic appearance of normal adrenal gland as well as adrenal tumors and tumor-like lesions.
- Published
- 2012
28. In Vivo Dual-Modality Terahertz/Magnetic Resonance Imaging Using Superparamagnetic Iron Oxide Nanoparticles as a Dual Contrast Agent
- Author
-
Jae Yeon Park, Hyuck Jae Choi, Kyoung-Sik Cho, Joo-Hiuk Son, and Gi-Eun Nam
- Subjects
Radiation ,Materials science ,medicine.diagnostic_test ,Terahertz radiation ,media_common.quotation_subject ,Nanoparticle ,Magnetic resonance imaging ,Nuclear magnetic resonance ,In vivo ,Cancer cell ,medicine ,Contrast (vision) ,Magnetic nanoparticles ,Electrical and Electronic Engineering ,Molecular imaging ,media_common - Abstract
Molecular imaging is one of the most promising tools for diagnosis of cancer. We assessed whether commercially available superparamagnetic iron oxide nanoparticles (SPIO; Feridex®) could be utilized as a dual modality contrast agent for terahertz (THz) imaging as well as magnetic resonance (MR) imaging. Feridex particles were transfected into SKOV3 cancer cells, at concentrations of 0, 0.35, 0.70, and 1.38 mM, and the magnetic and optical properties of the particles were examined by MR and THz reflection imaging. Mice were inoculated with Feridex-labeled SKOV3 cells, and in vivo MR and THz images were taken 1, 3, 7, and 14 days after inoculation. THz images and T2*-weighted MR images of Feridex-labeled SKOV3 tumors showed similar patterns; the signal intensities of both image sets increased with Feridex concentration. The signal intensity of in vivo MR and THz images from mice decreased over time. H&E and Prussian blue staining results correlated with imaging data. Dual-modality molecular MR and THz imaging of Feridex-labeled cells may be used to identify cancer cells both in vivo and in vitro. Such a noninvasive multimodal imaging method may be valuable in future cellular and molecular studies.
- Published
- 2012
29. Diagnosis of lymph node metastasis in uterine cervical cancer: usefulness of computer-aided diagnosis with comprehensive evaluation of MR images and clinical findings
- Author
-
Mi-Hyun Kim, Jeong Kon Kim, Kyoung-Sik Cho, Hyuck Jae Choi, Chang Kyung Lee, Bumwoo Park, Gyunggoo Cho, Namkug Kim, and Young-Joo Lee
- Subjects
Adult ,medicine.medical_specialty ,Lymphatic metastasis ,Uterine cervical cancer ,Biopsy ,Uterine Cervical Neoplasms ,Lymph node metastasis ,Sensitivity and Specificity ,Diagnosis, Differential ,Image Interpretation, Computer-Assisted ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Retrospective Studies ,Observer Variation ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,Echo-Planar Imaging ,Sentinel Lymph Node Biopsy ,business.industry ,Reproducibility of Results ,Bayes Theorem ,Retrospective cohort study ,General Medicine ,Middle Aged ,Diffusion Magnetic Resonance Imaging ,ROC Curve ,Computer-aided diagnosis ,Lymphatic Metastasis ,Treatment strategy ,Female ,Lymph Nodes ,Radiology ,Mr images ,business - Abstract
Background Lymph node (LN) status is an important parameter for determining the treatment strategy and for predicting the prognosis for patients with uterine cervical cancer. Computer-aided diagnosis (CAD) can be feasible for differentiating metastatic from non-metastatic lymph nodes in patients with uterine cervical cancer Purpose To determine the usefulness of CAD that comprehensively evaluates MR images and clinical findings for detecting LN metastasis in uterine cervical cancer. Material and Methods In 680 LNs from 143 patients who underwent radical hysterectomy for uterine cervical cancer, the CAD system using the Bayesian classifier estimated the probability of metastasis based on MR findings and clinical findings. We compared the diagnostic accuracy for detecting metastatic LNs in the CAD and MR findings. Results Metastasis was diagnosed in 70 (12%) LNs from 34 (24%) patients. The area under ROC curves of CAD (0.924) was greater than those of the mean ADC (0.854), minimum ADC (0.849), maximum ADC (0.827), short-axis diameter (0.856) and long-axis diameter (0.753) ( P < 0.05). The specificity and accuracy of the CAD (86%, 86%) were greater than those of the mean ADC (77%, 77%), maximum ADC (77%, 77%), minimum ADC (68%, 70%), and short-axis diameter (65%, 67%) ( P < 0.05). Conclusion CAD system can improve the diagnostic performance of MR for detecting metastatic LNs in uterine cervical cancer.
- Published
- 2011
30. Terahertz Pulse Imaging of Micro-metastatic Lymph Nodes in Early-stage Cervical Cancer Patients
- Author
-
Meehyun Lim, Kyoung-Sik Cho, Youngwoong Do, Haewook Han, E. Jung, Soonsung Lee, Kiwon Moon, Hyuck Jae Choi, and Kyu-Rae Kim
- Subjects
Cervical cancer ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Magnetic resonance imaging ,Lymph node metastasis ,medicine.disease ,Atomic and Molecular Physics, and Optics ,Positron emission tomography ,Terahertz pulse ,medicine ,Carcinoma ,Medical physics ,Radiology ,Lymph ,Stage (cooking) ,business - Abstract
Lymph node metastasis is an important prognostic factor in cervical cancer patients. We report THz imaging for detecting micro-metastatic foci in the lymph nodes of early-stage uterine cervical cancer patients. Five paraffin-embedded metastatic lymph nodes from two cervical cancer patients were imaged using a THz time-domain spectroscopy system in the reflection mode. The size and shape of the tumor regions were compared with those from histopathologic examinations. The metastatic portions of lymph nodes as small as 3 mm were well delineated by THz imaging. The reflected peak amplitudes were lower in metastatic portions than in the normal portions of lymph nodes, and the difference in their peak-to-peak amplitudes was ~5%.
- Published
- 2011
31. Value of T2-weighted MR imaging in differentiating low-fat renal angiomyolipomas from other renal tumors
- Author
-
Mi-Hyun Kim, Choung-Soo Kim, Hyuck Jae Choi, Kyoung-Sik Cho, Hanjong Ahn, and Jeong Kon Kim
- Subjects
Adult ,Male ,medicine.medical_specialty ,Angiomyolipoma ,Sensitivity and Specificity ,Diagnosis, Differential ,Renal cell carcinoma ,Adenoma, Oxyphilic ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Carcinoma, Renal Cell ,Aged ,Retrospective Studies ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,Magnetic resonance imaging ,General Medicine ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Mr imaging ,Kidney Neoplasms ,Tomography x ray computed ,ROC Curve ,Female ,Radiology ,Signal intensity ,Differential diagnosis ,Tomography, X-Ray Computed ,T2 weighted ,business ,Nuclear medicine - Abstract
Backgound Accurate preoperative diagnosis of fat scanty angiomyolipomas is an important clinical issue. By evaluating the low signal intensity of angiomyolipomas in MR T2-weighted images the diagnostic accuracy can be elevated. Purpose To retrospectively assess the usefulness of T2-weighted MR imaging for differentiating low-fat angiomyolipomas (AMLs) from other renal tumors. Material and Methods We retrospectively evaluated 71 patients with surgically proven renal masses (10 AMLs, 57 renal cell carcinomas [RCCs], and four oncocytomas), all of which showed no visible fat as well as gradual enhancement patterns on contrast-enhanced CT. Signal intensity was measured in each renal mass and in the spleen on T2-weighted images, and each signal intensity ratio (SIR) was calculated; SIR values were then compared in the AML and non-AML groups. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of the two parameters for differentiating the two groups. Results The SIR values (77 ± 24% vs. 162 ± 79%, p = 0.002) were significantly lower in the AML than in the non-AML group. The area under the ROC curve was 0.926 for SIR. The sensitivity and specificity in the diagnosis of AMLs were 90% and 90.2%, using SIR cut-off of 92.5%. Conclusion Signal intensity measurements on T2-weighted MR images can differentiate AML from non-AML in the kidney.
- Published
- 2011
32. The utility of multi-detector computed tomography in the diagnosis of malignant pleural effusion in the patients with ovarian cancer
- Author
-
Dae Chul Jung, Hyuck Jae Choi, Seung Hyup Kim, Jeong Yeon Cho, Sokbom Kang, Kyung Won Kim, Sang Yoon Park, and Kyung Sik Cho
- Subjects
medicine.medical_specialty ,Pleural effusion ,Contrast Media ,Metastasis ,Pleural disease ,Humans ,Medicine ,Malignant pleural effusion ,Radiology, Nuclear Medicine and imaging ,Aged ,Ovarian Neoplasms ,business.industry ,Respiratory disease ,General Medicine ,Middle Aged ,respiratory system ,medicine.disease ,Pleural Effusion, Malignant ,respiratory tract diseases ,Effusion ,Pleurisy ,Radiographic Image Interpretation, Computer-Assisted ,Female ,Radiology ,Tomography, X-Ray Computed ,business ,Ovarian cancer - Abstract
The purpose of this study was to retrospectively assess possible clinical predictors of malignant pleural effusion in patients with ovarian cancer.This review was performed on 38 ovarian cancer patients that showed pleural effusion in a CT scan and who underwent thoracocentesis before treatment. CT scans were obtained using a 4-channel multi-detector CT scanner. Fisher's exact test was used to determine the probability of malignant pleural effusion as a function of; amount of ascites, lymph node enlargement, amount of pleural effusion, pleural nodules, and pleural thickening.Sixteen (42.1%) of the 38 patients had malignant pleural effusion and malignant pleural effusion amounts were greater than those with nonmalignant effusion. Pleural nodules were more frequently found in the malignant pleural effusion group (eight [50%] patients) than in the nonmalignant group (zero [0%] patient) (p0.001). Supradiaphragmatic lymph node enlargement (with short axis diameter 1cm or more) was more frequent in malignant group (12 [75%] patients) than in the nonmalignant group (two [9.1%] patients) (p0.001).The probability of malignant pleural effusion in patients with ovarian cancer was found to be correlated with the amount of pleural effusion, the presence of pleural nodules, and supradiaphragmatic lymph node enlargement.
- Published
- 2010
33. Differential Diagnostic Performance of Magnetic Resonance Imaging in the Detection of Lymph Node Metastases According to the Tumor Size in Early-Stage Cervical Cancer Patients
- Author
-
Woong Ju, Kyuong Sik Cho, Hyuck Jae Choi, Kil Sun Hong, Jeong Kon Kim, and Mi-Hyun Kim
- Subjects
Adult ,Oncology ,medicine.medical_specialty ,medicine.medical_treatment ,Uterine Cervical Neoplasms ,Young Adult ,Internal medicine ,Positive predicative value ,medicine ,Humans ,Stage (cooking) ,Lymph node ,Aged ,Neoplasm Staging ,Retrospective Studies ,Cervical cancer ,medicine.diagnostic_test ,business.industry ,Obstetrics and Gynecology ,Magnetic resonance imaging ,Retrospective cohort study ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Lymphatic Metastasis ,Lymph Node Excision ,Female ,Lymphadenectomy ,Lymph Nodes ,Radiology ,Lymph ,business - Abstract
Objectives:The objective of this study was to evaluate the diagnostic performance in managing early-stage cervical cancer according to the International Federation of Gynecology and Obstetrics (FIGO) stage or tumor size.Methods/Materials:We performed a retrospective review of patients with FIGO stages IB1 to IIA cervical carcinoma who underwent magnetic resonance imaging (MRI) before lymphadenectomy. Lymphadenectomy involved all visible lymph nodes in the surgical fields. We compared the accuracy of MRI for detecting metastatic lymph nodes in the FIGO IB and IIA groups and in the nonbulky (≤4 cm) and bulky (>4) tumor groups. χ2 analysis was used to compare the accuracy of MRI for detecting metastatic lymph nodes. P ≤ 0.05 was considered statistically significant.Results:Three hundred five patients were included. Lymph node metastases were present in 49 (16.1%) of these patients. The sensitivity, specificity, and positive and negative predictive values were 7%, 99.3%, 31.3%, and 95.8% in the nonbulky tumor group and 43.8%, 97.1%, 70%, and 91.8% in the bulky tumor group (P = 0.001, P = 0.0097, P = 0.0479, and P = 0.0142, respectively).Conclusions:For predicting lymph node metastasis with MRI in early-stage cervical cancer patients, MRI showed a higher diagnostic performance in the bulky tumor group compared with that in the nonbulky tumor group and had a low value in the nonbulky tumor group, even when accounting for FIGO stage.
- Published
- 2010
34. Deep survival model indentified the prognostic subgroups in triple-negative breast cancer patients
- Author
-
Seonwoo Kim, Su-Yeon Lee, J.E. Lee, Jong Han Yu, In Wha Kim, S.J. Nam, J.M. Kim, Hyuck Jae Choi, and J.M. Ryu
- Subjects
Oncology ,Cancer Research ,medicine.medical_specialty ,business.industry ,Internal medicine ,medicine ,business ,Triple-negative breast cancer ,Survival analysis - Published
- 2018
35. Region-based diagnostic performance of multidetector CT for detecting peritoneal seeding in ovarian cancer patients
- Author
-
Hyuck Jae Choi, Sokbom Kang, Sang Soo Seo, Chong Woo Yoo, Sang Yoon Park, Jaeman Bae, Myong Cheol Lim, Dae Chul Jung, and Kyoung Sik Cho
- Subjects
Adult ,medicine.medical_specialty ,Neoplasm Seeding ,Multidetector ct ,Sensitivity and Specificity ,Predictive Value of Tests ,X ray computed ,Humans ,Medicine ,cardiovascular diseases ,Peritoneal Cavity ,Peritoneal Neoplasms ,Aged ,Ovarian Neoplasms ,business.industry ,Multi detector computed tomography ,Carcinoma ,Obstetrics and Gynecology ,Peritoneal seeding ,General Medicine ,Middle Aged ,medicine.disease ,Lymphatic Metastasis ,Predictive value of tests ,cardiovascular system ,Female ,Lymph ,Radiology ,Tomography, X-Ray Computed ,business ,Ovarian cancer - Abstract
To determine the accuracy of multi-detector CT (MDCT) compared with the surgical findings, such as peritoneal seeding and metastatic lymph nodes, in ovarian cancer patients.Fifty-seven FIGO stage IA-IV ovarian cancer patients, who underwent MDCT before primary surgery, were included in this study. Two radiologists evaluated the following imaging findings in consensus: the presence of nodular, plaque-like or infiltrative soft-tissue lesions in peritoneal fat or on the serosal surface; presence of ascites; parietal peritoneal thickening or enhancement; and small bowel wall thickening or distortion. We also evaluated the presence of lymph node metastases. To allow region-specific comparisons, the peritoneal cavity was divided into 13 regions and retroperitoneal lymph nodes were divided into 3 regions. Descriptive statistical data were thus obtained.The MDCT sensitivity, specificity, positive predictive values, and negative predictive values were 45, 72, 46, and 72%, respectively, for detecting peritoneal seeding and 21, 90, 52, and 69%, respectively, for detecting lymph node metastasis.MDCT is moderately accurate for detecting peritoneal metastasis and lymph node metastasis in ovarian cancer patients.
- Published
- 2010
36. Comparison of Laparoscopy and Laparotomy for Management of Endometrial Carcinoma: A Meta-analysis
- Author
-
Hyuck Jae Choi, Seung Cheol Kim, Yeol Kim, Seung-Kwon Myung, and Woong Ju
- Subjects
Laparoscopic surgery ,medicine.medical_specialty ,MEDLINE ,medicine.medical_treatment ,Gynecologic Surgical Procedures ,Laparotomy ,Carcinoma ,Humans ,Medicine ,Laparoscopy ,Survival rate ,Clinical Trials as Topic ,medicine.diagnostic_test ,business.industry ,General surgery ,Endometrial cancer ,Obstetrics and Gynecology ,Odds ratio ,medicine.disease ,Confidence interval ,Endometrial Neoplasms ,Survival Rate ,Oncology ,Female ,Lymph Nodes ,Neoplasm Recurrence, Local ,business - Abstract
Background:This meta-analysis was performed to investigate the outcome of laparoscopic surgery for endometrial carcinoma compared with laparotomy.Methods:We searched the MEDLINE (PubMed), EMBASE, and Cochrane Review databases in September 2007. Three independent evaluators selected the articles according to predetermined selection criteria.Results:Thirteen comparative studies (5 prospective and 8 retrospective) that met the selection criteria were included. In a fixed-effects meta-analysis, the overall survival and therecurrence rate showed no significant differences between the laparoscopy and the laparotomy groups, with odds ratios of 0.84 (95% confidence interval, 0.64-1.62) and 0.90 (95% confidence interval, 0.49-1.16), respectively. However, the complication rate was lower in the laparoscopy group than in the laparotomy group with an odds ratio of 0.43 (95% confidence interval, 0.32-0.58).Conclusions:The survival outcome and recurrence rate after laparoscopic surgery for endometrial carcinoma were similar to those in the laparotomy procedures. However, the complication rate was lower after laparoscopy compared with laparotomy.
- Published
- 2009
37. Endometrioid Adenocarcinoma in Urethrovaginal Septum: A Diagnostic Pitfall
- Author
-
Myong Cheol Lim, Sang Yoon Park, Sun Lee, Hyuck Jae Choi, Seung Mi Lee, Chu Yeop Huh, and Jung Yun Lee
- Subjects
Pathology ,medicine.medical_specialty ,Vaginal Neoplasms ,Symphysis ,Endometriosis ,Vaginal neoplasm ,Case Report ,Biology ,Diagnosis, Differential ,Biopsy ,Carcinoma ,medicine ,Humans ,Lymph node ,Urethral Neoplasms ,medicine.diagnostic_test ,General Medicine ,Middle Aged ,medicine.disease ,Urethrovaginal Septum ,Magnetic Resonance Imaging ,Endometrial Neoplasms ,Dissection ,medicine.anatomical_structure ,Female ,Differential diagnosis ,Carcinoma, Endometrioid - Abstract
Primary endometrioid adenocarcinoma developed at urethrovaginal septum has not been reported. A 61-yr-old woman presented with recurrent urinary tract infection. She had received hormone replacement treatment with estrogen and progesterone for 5 yr. A pinpoint ulceration at slightly elevated anterior vaginal wall was found and biopsy revealed endometrioid adenocarcinoma. Magnetic resonance imaging showed the 4.3 cm sized mass in urethrovaginal septum. She has undergone anterior pelvic exenteration, pelvic lymph node dissection, and urostomy with ileal conduit. Microscopic finding of the pathology revealed endometrioid adenocarcinoma. Co-existence of endometriosis was not identified. Tumor at urethrovaginal septum was difficult to be detected till growing to be bulky, because of vaginal axis, misunderstanding of the tumor as symphysis pubis, no definitive symptom, and its rarity. This is the first reported case of extraovarian endometrioid adenocarcinoma developed at the urethrovaginal septum. Understanding normal functional anatomy and meticulous physical examination are essential to detect this rare tumor in the urethrovaginal septum.
- Published
- 2009
38. The validity of tumour diameter assessed by magnetic resonance imaging and gross specimen with regard to tumour volume in cervical cancer patients
- Author
-
Hyuck Jae Choi, Woong Ju, Sohee Park, Chong Woo Yoo, Sang Yoon Park, Sokbom Kang, and Dae Chul Jung
- Subjects
Adult ,Male ,Cancer Research ,Slice thickness ,Uterine Cervical Neoplasms ,Stage ib ,Humans ,Medicine ,In patient ,Neoplasm Staging ,Retrospective Studies ,Cervical cancer ,medicine.diagnostic_test ,business.industry ,Carcinoma ,Magnetic resonance imaging ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Standard technique ,Tumor Burden ,Oncology ,Female ,Tumour volume ,business ,Nuclear medicine ,Tumour diameter - Abstract
We compared the tumour size measured by magnetic resonance imaging (MRI) with that of gross specimen regarding the virtual tumour volume. Eighty three patients with International Federation of Obstetrics and Gynecology (FIGO) stage Ib to IIa cervical cancer underwent MRI before radical hysterectomy. The largest tumour diameter was determined by both MRI and gross specimen measurement. Tumour volume was calculated by the standard technique of multiplying the sum of the areas by the slice thickness. Paired t-test was used to compare the MRI and gross specimen derived diameters. Pearson correlation coefficient was calculated to evaluate the relationship between the tumour size and volume. The mean diameters of the MRI and gross specimen derived tumour measurements were 3.0 cm (standard deviation, 0.9 cm) and 3.5 cm (standard deviation, 1.2 cm) (p0.001), respectively. Mean MRI-based tumour volume was 12.5 cm(3) (standard deviation, 10.4 cm(3)). Tumour diameter measured by MRI had a significantly higher correlation with tumour volume measured by MRI (r(p)=0.734) compared with that measured on the gross specimen (r(p)=0.690; Steiger's Z test, p=0.019). The tumour diameter measured by MRI was smaller than gross specimen measurement and correlated more closely with tumour volume in patients with cervical cancer. This study illustrates the value of MRI as a tool for tumour size measurement.
- Published
- 2008
39. Discordant MRI/FDG-PET imaging for the diagnosis of borderline ovarian tumors
- Author
-
Seungchul Kim, Hyuck Jae Choi, Kyungsun Choi, Dae Chul Jung, and Woong Ju
- Subjects
Adult ,medicine.medical_specialty ,Adolescent ,Standardized uptake value ,Surgical staging ,Sensitivity and Specificity ,Diagnosis, Differential ,Fluorodeoxyglucose F18 ,medicine ,Humans ,Aged ,Retrospective Studies ,Ovarian Neoplasms ,medicine.diagnostic_test ,business.industry ,Fdg uptake ,Carcinoma ,Obstetrics and Gynecology ,Magnetic resonance imaging ,Retrospective cohort study ,Pet imaging ,Middle Aged ,Magnetic Resonance Imaging ,Tumor Burden ,Oncology ,Positron emission tomography ,Positron-Emission Tomography ,Female ,Borderline ovarian tumors ,Radiology ,business ,Precancerous Conditions - Abstract
The objective of this study was to assess the role of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) for the characterization of ovarian masses that were diagnosed as ovarian malignancies by magnetic resonance imaging (MRI). We performed a retrospective review of eight patients with pathologically confirmed borderline ovarian tumors (BOT) who underwent MRI and FDG-PET before surgical staging from August 2005 to March 2007. We assessed the PET imaging of the BOT, measured the FDG uptake and quantified the findings as a standardized uptake value (SUV). The FDG-PET scans, of all eight patients, showed uptake of FDG with a mean SUV of less than 2.0 in the solid portion of the masses evaluated. We conclude that the MRI-PET differences may help differentiate borderline from malignant ovarian tumors.
- Published
- 2008
40. Hematuria: Portal Venous Phase Multi–Detector Row CT of the Bladder—A Prospective Study
- Author
-
Sung Bin Park, Hyun Joo Lee, Kyoung-Sik Cho, Hyuck Jae Choi, and Jeong Kon Kim
- Subjects
Adult ,Male ,medicine.medical_specialty ,Adolescent ,Portal venous phase ,Lesion ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Prospective cohort study ,Aged ,Hematuria ,Aged, 80 and over ,Urinary bladder ,medicine.diagnostic_test ,Portal Vein ,business.industry ,Urinary Bladder Diseases ,Reproducibility of Results ,Cystoscopy ,Middle Aged ,Institutional review board ,Multi detector ,medicine.anatomical_structure ,Urinary Bladder Neoplasms ,Female ,Radiology ,Tomography ,medicine.symptom ,Tomography, X-Ray Computed ,business - Abstract
To prospectively determine the accuracy of portal venous phase helical multi-detector row computed tomography (CT) for bladder lesion evaluation in patients with hematuria by using cystoscopy as the reference standard.The study was approved by the institutional review board for human investigation, and informed consent was obtained from all patients. This study included 118 patients (91 male, 27 female; age range, 15-87 years; mean age +/- standard deviation, 62 years +/- 14) who underwent portal venous phase multi-detector row CT (scanning delay, 70 seconds; section thickness, 2 mm) and conventional cystoscopy because of painless gross hematuria or recurrent microscopic hematuria. Two reviewers with different experience levels independently evaluated the bladder for lesions at CT in a prospective fashion. The kappa statistic was used to determine the per lesion and per patient agreement between the two reviewers and between the CT and cystoscopic findings. The sensitivity and specificity of multi-detector row CT for bladder lesion detection were analyzed for numbers of lesions and for numbers of patients.Multi-detector row CT showed excellent per lesion (kappa = 0.839) and per patient (kappa = 0.881) agreement between the two reviewers. Respective per lesion and per patient agreement between the CT and cystoscopic findings was also excellent in the first (kappa = 0.866 and kappa = 0.881) and second (kappa = 0.802 and kappa = 0.863) reviewers. The sensitivity and specificity of multi-detector row CT were 89%-92% and 88%-97%, respectively, in the per lesion analysis and 95% and 91%-93%, respectively, in the per patient analysis for both reviewers. All statistical parameters of diagnostic accuracy were similar between the two reviewers (P.05).Portal venous phase multi-detector row CT can provide high accuracy and reader agreement for bladder lesion detection in patients with painless gross hematuria and recurrent microscopic hematuria; these results indicate that multi-detector row CT can be used as the initial bladder examination in such patients.
- Published
- 2007
41. The role of pelvic exenteration and reconstruction for treatment of advanced or recurrent gynecologic malignancies: Analysis of risk factors predicting recurrence and survival
- Author
-
Seung-Yong Jeong, Jinsoo Chung, Hyuck Jae Choi, Sang Yoon Park, Jung Kun Park, and Jeong-Yeol Park
- Subjects
Adult ,medicine.medical_specialty ,Multivariate analysis ,Genital Neoplasms, Female ,medicine.medical_treatment ,Lymph node metastasis ,Risk Factors ,medicine ,Overall survival ,Humans ,Prospective Studies ,Prospective cohort study ,Aged ,Pelvic exenteration ,business.industry ,Mortality rate ,General Medicine ,Middle Aged ,Plastic Surgery Procedures ,Pelvic Exenteration ,Surgery ,Predictive factor ,Gynecologic malignancy ,Oncology ,Female ,Neoplasm Recurrence, Local ,business - Abstract
Background and Objectives Pelvic exenteration offers the last chance of cure for some advanced or recurrent gynecologic malignancy patients. The aim of this prospective study was to analyze factors associated with recurrence and survival after pelvic exenteration. Methods Forty-six women with advanced or recurrent gynecologic malignancies were enrolled between July 2001 and February 2006. All pelvic exenteration surgery was performed by the same gynecological oncologist. Results Two patients were excluded due to the discovery of peritoneal disease during surgery. Multivariate analysis showed that a tumor size >4 cm was the only factor associated with risk of recurrence after surgery (P = 0.014), that margin status was the only factor associated with disease-free survival (P = 0.0.047), and that margin status and lymph node metastasis were associated with overall survival (P = 0.017 and 0.012, respectively). Conclusions Pelvic exenteration and reconstruction was found to have a potential to provide long-term survival without postoperative mortality although the morbidity rate is somewhat high. Multivariate analysis showed that tumor size >4 cm was a predictive factor for recurrence, and that margin status and lymph node metastasis were predictive factors for survival. J. Surg. Oncol. 2007;96:560–568. © 2007 Wiley-Liss, Inc.
- Published
- 2007
42. Rapidly Progressing Malignant Epithelioid Renal Angiomyolipoma: A Case Report
- Author
-
Seong Whi, Cho, Hyuck Jae, Choi, and Seunkoo, Lee
- Subjects
Image-Guided Biopsy ,Angiomyolipoma ,Middle Aged ,Kidney ,Magnetic Resonance Imaging ,Nephrectomy ,Kidney Neoplasms ,Biomarkers, Tumor ,Disease Progression ,Humans ,Female ,Tomography, X-Ray Computed ,Melanoma-Specific Antigens ,Follow-Up Studies ,gp100 Melanoma Antigen - Published
- 2015
43. Effect of Music on Reducing Anxiety for Patients Undergoing Transrectal Ultrasound-Guided Prostate Biopsies: Randomized Prospective Trial
- Author
-
Seong Whi, Cho and Hyuck Jae, Choi
- Subjects
Male ,Prostatic Diseases ,Prostate ,Rectum ,Pain ,Anxiety ,Middle Aged ,Treatment Outcome ,Humans ,Pain Management ,Prospective Studies ,Endoscopic Ultrasound-Guided Fine Needle Aspiration ,Music Therapy ,Follow-Up Studies - Abstract
The purpose of this study was to assess the impact of music on anxiety and perceived pain during transrectal ultrasound-guided prostate biopsy.Forty consecutive men with an elevated serum prostate specific antigen (PSA) level and/ or an abnormal digital rectal examination referred for transrectal ultrasound-guided prostate biopsy were recruited and allocated to a music (n = 20) or a non-music (n = 20) group. Anxiety was assessed prior to and after biopsy and pain was assessed after biopsy in each patient using visual analog scales (VAS) in the same setting, and group anxiety scores were compared.Patients in the music group experienced less anxiety (P = .046) during the procedure, but group pain scores were not significantly different.Music was found to decrease anxiety effectively during transrectal ultrasound-guided prostate biopsy.
- Published
- 2015
44. Human Papillomavirus E6/E7-Specific siRNA Potentiates the Effect ofRadiotherapy for Cervical Cancer in Vitro and in Vivo
- Author
-
Yoon-La Choi, Sang Yong Song, Nirmal Rajasekaran, Hun Soon Jung, Young Kee Shin, Young Deug Kim, Hyuck Jae Choi, Sungyoul Hong, Jong-Sun Choi, and Young Seok Kim
- Subjects
Small interfering RNA ,Radiation-Sensitizing Agents ,cervical cancer ,Papillomavirus E7 Proteins ,Uterine Cervical Neoplasms ,lcsh:Chemistry ,HeLa ,Mice ,Medicine ,RNA, Small Interfering ,lcsh:QH301-705.5 ,Spectroscopy ,E7 ,E6 ,Cervical cancer ,Human papillomavirus 16 ,biology ,Human papillomavirus 18 ,General Medicine ,Transfection ,Combined Modality Therapy ,female genital diseases and pregnancy complications ,Computer Science Applications ,Female ,Radiosensitizer ,Cell Survival ,Catalysis ,Article ,Inorganic Chemistry ,In vivo ,Animals ,Humans ,Viability assay ,Physical and Theoretical Chemistry ,Molecular Biology ,radiotherapy ,Cell Proliferation ,radiosensitizer ,Oncogene ,business.industry ,Organic Chemistry ,Papillomavirus Infections ,Oncogene Proteins, Viral ,medicine.disease ,biology.organism_classification ,Molecular biology ,Xenograft Model Antitumor Assays ,lcsh:Biology (General) ,lcsh:QD1-999 ,siRNA ,Concurrent Chemoradiation therapy (CCRT) ,business ,HeLa Cells - Abstract
The functional inactivation of TP53 and Rb tumor suppressor proteins by the HPV-derived E6 and E7 oncoproteins is likely an important step in cervical carcinogenesis. We have previously shown siRNA technology to selectively silence both E6/E7 oncogenes and demonstrated that the synthetic siRNAs could specifically block its expression in HPV-positive cervical cancer cells. Herein, we investigated the potentiality of E6/E7 siRNA candidates as radiosensitizers of radiotherapy for the human cervical carcinomas. HeLa and SiHa cells were transfected with HPV E6/E7 siRNA, the combined cytotoxic effect of E6/E7 siRNA and radiation was assessed by using the cell viability assay, flow cytometric analysis and the senescence-associated β-galactosidase (SA-β-Gal) assay. In addition, we also investigated the effect of combined therapy with irradiation and E6/E7 siRNA intravenous injection in an in vivo xenograft model. Combination therapy with siRNA and irradiation efficiently retarded tumor growth in established tumors of human cervical cancer cell xenografted mice. In addition, the chemically-modified HPV16 and 18 E6/E7 pooled siRNA in combination with irradiation strongly inhibited the growth of cervical cancer cells. Our results indicated that simultaneous inhibition of HPV E6/E7 oncogene expression with radiotherapy can promote potent antitumor activity and radiosensitizing activity in human cervical carcinomas.
- Published
- 2015
45. CT Findings of Clear Cell Carcinoma of the Ovary
- Author
-
Hyuck Jae Choi, Sun Lee, Joon-Il Choi, Joo-Hyuk Lee, Sang-Soo Seo, Sang Yoon Park, Sokbom Kang, and Jong Seok Lee
- Subjects
Adult ,Ovarian Neoplasms ,medicine.medical_specialty ,business.industry ,Lumen (anatomy) ,Ovary ,Middle Aged ,medicine.disease ,medicine.anatomical_structure ,Hounsfield scale ,Clear cell carcinoma ,medicine ,Carcinoma ,Humans ,Female ,Radiology, Nuclear Medicine and imaging ,Radiology ,Tomography ,Ct findings ,Tomography, X-Ray Computed ,business ,Carcinoma, Renal Cell ,Clear cell ,Aged ,Retrospective Studies - Abstract
Purpose The purpose of this article was to retrospectively evaluate computed tomographic (CT) findings in patients with pathologically proved clear cell carcinoma of the ovary. Methods CT scans of seven patients (age range, 28-79 years; mean age, 46 years) with nine lesions of histologically proved primary ovarian clear cell carcinoma of the ovary were retrospectively evaluated by two radiologists in consensus. Scans were evaluated for the laterality, size, mass characteristic, margin, attenuation of the cystic portion, internal architecture, and presence of lumen protruding mass. Results Tumors were unilateral in five patients. The average size of the tumors was 8.6 cm (range, 2.6-12.1 cm). All the masses showed mainly cystic appearance. All nine masses had smooth margin. Average attenuation of the cystic portion of the masses was 24.2 HU (Hounsfield unit) (range, 13-34 HU). Tumors usually appeared as unilocular cystic mass (n=6). Lumen protruding masses appeared in seven tumors. Conclusion On CT scans, primary ovarian clear cell carcinomas appeared as large unilocular, mainly cystic, smooth marginated mass with lumen protruding solid portion and high-attenuated cystic portion.
- Published
- 2006
46. MRI for Pretreatment Lymph Node Staging in Uterine Cervical Cancer
- Author
-
Sun Lee, Seung Hyup Kim, Sokbom Kang, Hyun Hoon Chung, Joo-Young Kim, Young Hoon Kim, Hyuck Jae Choi, San Soo Seo, Jongmin Lee, Joo Hyuk Lee, and Sang Yoon Park
- Subjects
Adult ,Oncology ,medicine.medical_specialty ,Uterine cervical cancer ,Adolescent ,medicine.medical_treatment ,Uterine Cervical Neoplasms ,Lymph node metastasis ,Hysterectomy ,Sensitivity and Specificity ,Pelvis ,Metastasis ,Paraaortic lymph nodes ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Aorta, Abdominal ,Lymph node staging ,Aged ,Neoplasm Staging ,Cervical cancer ,business.industry ,Cancer ,General Medicine ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Lymphatic Metastasis ,Lymph Node Excision ,Female ,Lymph Nodes ,Radiology ,business - Abstract
OBJECTIVE. The purpose of this article is to assess the accuracy of MRI in detecting pelvic and paraaortic lymph node metastasis from uterine cervical cancer using various imaging criteria.CONCLUSION. Although MRI analysis resulted in relatively low sensitivity, size and margin (spiculated or lobulated) were useful criteria for predicting lymph node metastasis from cervical cancer.
- Published
- 2006
47. Contrast-Enhanced CT for Differentiation of Ovarian Metastasis from Gastrointestinal Tract Cancer: Stomach Cancer Versus Colon Cancer
- Author
-
Sun Lee, Sokbom Kang, Sang-Soo Seo, Joon-Il Choi, Sang Yoon Park, Hyuck Jae Choi, and Joo-Hyuk Lee
- Subjects
Adult ,Male ,endocrine system ,Pathology ,medicine.medical_specialty ,endocrine system diseases ,Colorectal cancer ,Iohexol ,Contrast Media ,Ovary ,Metastasis ,Diagnosis, Differential ,Stomach Neoplasms ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Gastrointestinal cancer ,Stomach cancer ,Retrospective Studies ,Ovarian Neoplasms ,Gastrointestinal tract ,business.industry ,Cancer ,Retrospective cohort study ,General Medicine ,Middle Aged ,medicine.disease ,female genital diseases and pregnancy complications ,medicine.anatomical_structure ,Colonic Neoplasms ,Female ,Tomography, X-Ray Computed ,business - Abstract
OBJECTIVE. The purpose of our study was to determine whether the CT findings of ovarian metastasis from stomach cancer differ from those of ovarian metastasis from colon cancer.CONCLUSION. On contrast-enhanced CT scans, ovarian metastatic lesions from stomach cancer appear more solid than, more frequently have dense enhancement of the solid portion, and are smaller than ovarian metastatic lesions from colon cancer.
- Published
- 2006
48. Comparison of the accuracy of magnetic resonance imaging and positron emission tomography/computed tomography in the presurgical detection of lymph node metastases in patients with uterine cervical carcinoma
- Author
-
Keon Wook Kang, Jong Seok Lee, Sun Lee, Hyuck Jae Choi, Sang-Soo Seo, Jun Yong Jeong, Seok-Ki Kim, Ju Won Roh, Joo-Young Kim, and Sang Yoon Park
- Subjects
Adult ,Cancer Research ,medicine.medical_specialty ,medicine.medical_treatment ,Uterine Cervical Neoplasms ,Sensitivity and Specificity ,medicine ,Humans ,Prospective Studies ,Stage (cooking) ,Lymph node ,Aged ,Cervical cancer ,PET-CT ,medicine.diagnostic_test ,business.industry ,Carcinoma ,Reproducibility of Results ,Magnetic resonance imaging ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,medicine.anatomical_structure ,Oncology ,Positron emission tomography ,Lymphatic Metastasis ,Positron-Emission Tomography ,Lymph Node Excision ,Female ,Lymphadenectomy ,Radiology ,Lymph ,Tomography, X-Ray Computed ,business - Abstract
BACKGROUND The objective of the current study was to determine the accuracy of magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) for detecting lymph node metastases in patients with uterine cervical carcinoma compared with thin-section histopathologic results from systemic lymphadenectomy. METHODS Twenty-two patients with International Federation of Obstetrics and Gynecology (FIGO) Stage IB–IVA cervical carcinoma who underwent both MRI and PET/CT before lymphadenectomy were included in this study. Lymphadenectomy involved removing all visible lymph nodes in the surgical fields. To enable region-specific comparisons, paraaortic and pelvic lymph nodes were divided into seven regions: the paraaortic area, both common iliac areas, both external iliac areas, and both internal iliac/obturator areas. Histopathologic evaluation of lymph nodes was the diagnostic standard. Chi-square analysis was used to compare the accuracy of MRI and PET/CT for the detection of metastatic lymph nodes. A P value ≤ 0.05 was considered statistically significant. RESULTS With MRI, the sensitivity, specificity, and accuracy rates for detecting metastatic lymph nodes in each lymph node group were 30.3% (10 of 33 lymph node groups), 92.6% (112 of 121 lymph node groups), and 72.7% (122 of 154 lymph node groups), respectively; with PET/CT, those rates were 57.6% (19 of 33 lymph node groups), 92.6% (112 of 121 lymph node groups), and 85.1% (131 of 154 lymph node groups), respectively. Statistical analysis showed that PET/CT was more sensitive than MRI (P = 0.026) but that there were no statistical differences noted with regard to specificity (P = 1.000) or accuracy (P = 0.180). Power analysis demonstrated that a sample size of 685 lymph node groups (98 patients) would be necessary to demonstrate that PET/CT was more accurate than MRI (α = 0.05; β = 0.80). CONCLUSIONS PET/CT was more sensitive than MRI for detecting lymph node metastases in patients with uterine cervical carcinoma. Cancer 2006. © 2006 American Cancer Society.
- Published
- 2006
49. Computed Tomography Findings of Ovarian Metastases From Colon Cancer
- Author
-
Jong Seok Lee, Sang-Soo Seo, Sun Lee, Joo-Hyuk Lee, Joo-Young Kim, Young Hoon Kim, Hyuck Jae Choi, Sang Yoon Park, and Seok Ki Kim
- Subjects
Adult ,medicine.medical_specialty ,Pathology ,Colorectal cancer ,Iohexol ,Contrast Media ,Metastasis ,Neoplasm Seeding ,Text mining ,Ascites ,Image Processing, Computer-Assisted ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Lymph node ,Peritoneal Neoplasms ,Aged ,Aged, 80 and over ,Ovarian Neoplasms ,Univariate analysis ,business.industry ,Odds ratio ,Middle Aged ,medicine.disease ,Adenocarcinoma, Mucinous ,Confidence interval ,Cystadenocarcinoma, Serous ,Radiographic Image Enhancement ,medicine.anatomical_structure ,Colonic Neoplasms ,Myometrium ,Female ,Lymph Nodes ,Radiology ,medicine.symptom ,Tomography, X-Ray Computed ,business - Abstract
Objective: The computed tomography (CT) findings of ovarian metastases from colon cancer were evaluated and were compared with those of primary malignant ovarian tumors. Methods: Sixteen patients with 21 masses from coloncancer and 20 patients with 31 primary malignant ovarian tumors were included in this study. The CT findings (laterality, size, margin, shape, mass characteristic, strong enhancement of cyst wall, enhancement of solid portion, amount of ascites, peritoneal seeding, lymph node enlargement, and metastasis) and ages of the patients in both groups were compared. Univariate analysis, the Pearson Χ 2 test, and the independent-samples t test were used to distinguish them. Results: A smooth margin of the tumor (odds ratio = 24.3, 95% confidence interval: 2.9-204.2) and cystic nature of the mass (Pearson Χ 2 = 12.96, P = 0.005) were strong predictors of ovarian metastasis from colon cancer. Conclusion: Ovarian metastases from colon cancer show a smooth margin and more cystic nature on CT compared with primary malignant ovarian tumors.
- Published
- 2005
50. Preoperative Magnetic Resonance Imaging Staging of Uterine Cervical Carcinoma
- Author
-
Hyuck Jae Choi, Byung Kwan Park, Hak Jong Lee, Seung Hyup Kim, and Seung Hong Choi
- Subjects
Adult ,medicine.medical_specialty ,Uterine Cervical Neoplasms ,Lymph node metastasis ,Sensitivity and Specificity ,Preoperative care ,Predictive Value of Tests ,Preoperative Care ,Biopsy ,Cervical carcinoma ,medicine ,Humans ,False Positive Reactions ,Neoplasm Invasiveness ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Prospective cohort study ,Aged ,Neoplasm Staging ,medicine.diagnostic_test ,Parametrial ,business.industry ,Carcinoma ,Magnetic resonance imaging ,Middle Aged ,Magnetic Resonance Imaging ,Lymphatic Metastasis ,Predictive value of tests ,Female ,Radiology ,business - Abstract
Objective To determine the accuracy of the preoperative staging of uterine cervical cancer by magnetic resonance (MR) imaging in 115 patients in a prospective study. Methods A prospective study was performed in 115 patients who underwent MR imaging at 1.5 T before surgery or biopsy. Histopathologic findings were correlated with MR imaging results for all patients. Results The accuracy of preoperative tumor staging by MR imaging in the 115 patients was 77%. In terms of the evaluation of parametrial status, this study had an accuracy of 94% and a sensitivity of 38%. The accuracy and sensitivity of MR imaging for vaginal invasion were 81% and 87%, respectively. In terms of lymph node metastasis, this study had an accuracy of 97% and a sensitivity of 36%. Conclusion Magnetic resonance imaging has high accuracy in the preoperative staging of uterine cervical cancer.
- Published
- 2004
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.