1.Comparison of MicroFlow Imaging with color and power Doppler imaging for detecting and characterizing blood flow signals in hepatocellular carcinoma
Jae Seok BAE ; Jeong Min LEE ; Sun Kyung JEON ; Siwon JANG
Ultrasonography 2020;39(1):85-93
Purpose:
The purpose of this study was to compare the sensitivity of MicroFlow Imaging (MFI) with that of color and power Doppler imaging (CDI and PDI, respectively) in detecting the vascularity of hepatocellular carcinomas (HCCs).
Methods:
This prospective study enrolled 51 patients diagnosed with HCC between August 2018 and December 2018. CDI, PDI, MFI, and contrast-enhanced ultrasound (CEUS) were performed. Two radiologists evaluated the presence and pattern of tumoral vascularity on CDI, PDI, and MFI. Vascular presence was graded on a 5-point scale (0, absent; 4, >50% of the tumor). The vascular pattern was chosen from following categories: basket, vessels in tumor, spot, detouring, mixed, or others. Two additional radiologists assessed CEUS images for the presence and pattern of tumoral vascularity, which served as the reference standard. If the tumoral vascular pattern on each examination matched that of the CEUS images, the Wilcoxon test and McNemar test, respectively, were used to compare the sensitivity for detecting tumoral vascularity between MFI and CDI, and between MFI and PDI. Logistic regression analysis was performed to identify factors associated with MFI detectability of tumoral vascularity.
Results:
CEUS demonstrated tumoral vascularity in 98.0% (50 of 51) of patients. MFI (58.0%, 29 of 50) demonstrated a higher sensitivity than CDI (14.0%, 7 of 50) or PDI (14.0%, 7 of 50) (P<0.001 for both) in detecting tumoral vascularity, provided that the vascular pattern was correctly depicted. Only tumor depth was associated with the MFI detectability of tumoral vascularity.
Conclusion
The sensitivity of MFI was higher than that of CDI or PDI in detecting the vascularity of HCCs when the vascular pattern was considered. MFI better detected the vascularity of shallow tumors.
2.Development and Verification of Nested PCR Assay for Detection of Tobacco rattle virus in Plant Quarantine.
Siwon LEE ; Jin Young LEE ; Yong Gil SHIN ; Su Heon LEE ; Tae Young AHN
Journal of Bacteriology and Virology 2015;45(1):54-61
Tobacco rattle virus (TRV) is a plant pathogen belonging to the Group IV positive-sense single-stranded RNA viruses. TRV causes disease in various plants (e.g., potato, tomato and tobacco), for which it was classified as a controlled quarantine virus in Korea. This study aimed to develop specific primer sets for the rapid detection of TRV. Two RT-PCR primer sets were developed for specific detection of TRV. Furthermore, nested primer sets were also developed, which is required for high sensitivity detection in plant quarantine. The RT-PCR and nested PCR products had the following sizes: set 5 (1,096-->540 bp), and set 7 (878-->756 bp), respectively. In addition, a modified positive-control plasmid was also developed for use as a positive control in TRV quarantine. The diagnostic system for TRV detection was verified using samples from Korean quarantine sites for the last five years (2009-2014). A total of 83 cases were detected among various import crops. This system for detection of TRV will continuously contribute to plant quarantine in the future.
Korea
;
Lycopersicon esculentum
;
Plants*
;
Plasmids
;
Polymerase Chain Reaction*
;
Quarantine*
;
RNA Viruses
;
Solanum tuberosum
;
Tobacco*
3.Muscular Sarcoidosis Detected by F-18 FDG PET/CT in a Hypercalcemic Patient.
Eun Ji HAN ; Yi Sun JANG ; In Suk LEE ; Jong Min LEE ; Siwon KANG ; Hye Soo KIM
Journal of Korean Medical Science 2013;28(9):1399-1402
Sarcoidosis is a systemic granulomatous disease of unknown etiology that involves many organs, occasionally mimicking malignancy. We herein report a 50-yr-old woman of muscular sarcoidosis of chronic myopathic type, manifested by hypercalcemia and muscle wasting. Besides insignificant hilar lymphadenopathy, her sarcoidosis was confined to generalized atrophic muscles and therefore, F-18 FDG PET/CT alone among conventional imaging studies provided diagnostic clues for the non-parathyroid-related hypercalcemia. On follow-up PET/CT during low-dose steroid treatment, FDG uptake in the muscles disappeared whereas that in the hilar lymph nodes remained. PET/CT may be useful in the evaluation of unexpected disease extent and monitoring treatment response in suspected or known sarcoidosis patients.
Female
;
Fluorodeoxyglucose F18/*diagnostic use
;
Humans
;
Hypercalcemia/complications/*diagnosis
;
Kidney Calculi/complications/diagnosis
;
Lymph Nodes/radionuclide imaging
;
Middle Aged
;
Positron-Emission Tomography
;
Radiopharmaceuticals/*diagnostic use
;
Sarcoidosis/complications/drug therapy/*radionuclide imaging
;
Steroids/therapeutic use
;
Tomography, X-Ray Computed
4.Phylogeny of Flavobacteria Group Isolated from Freshwater Using Multilocus Sequencing Analysis.
Seyoung MUN ; Jungnam LEE ; Siwon LEE ; Kyudong HAN ; Tae Young AHN
Genomics & Informatics 2013;11(4):272-276
Sequence analysis of the 16S rRNA gene has been widely used for the classification of microorganisms. However, we have been unable to clearly identify five Flavobacterium species isolated from a freshwater by using the gene as a single marker, because the evolutionary history is incomplete and the pace of DNA substitutions is relatively rapid in the bacteria. In this study, we tried to classify Flavobacterium species through multilocus sequence analysis (MLSA), which is a practical and reliable technique for the identification or classification of bacteria. The five Flavobacterium species isolated from freshwater and 37 other strains were classified based on six housekeeping genes: gyrB, dnaK, tuf, murG, atpA, and glyA. The genes were amplified by PCR and subjected to DNA sequencing. Based on the combined DNA sequence (4,412 bp) of the six housekeeping genes, we analyzed the phylogenetic relationship among the Flavobacterium species. The results indicated that MLSA, based on the six housekeeping genes, is a trustworthy method for the identification of closely related Flavobacterium species.
Bacteria
;
Base Sequence
;
Classification
;
DNA
;
Flavobacterium
;
Fresh Water*
;
Genes, Essential
;
Genes, rRNA
;
Multilocus Sequence Typing
;
Phylogeny*
;
Polymerase Chain Reaction
;
Sequence Analysis
;
Sequence Analysis, DNA
5.A Healthcare-Associated Outbreak of HCV Genotype 2a at a Clinic in Seoul
Siwon CHOI ; Hyerim LEE ; Hyungmin LEE ; Yoon-Seok CHUNG
Osong Public Health and Research Perspectives 2021;12(1):3-12
Objectives:
An epidemiological investigation was conducted into a hepatitis C virus (HCV) outbreak at an outpatients clinic in Seoul (2011-2012). The aim of the study was to analyze the scale of infection, identify the source of infection, and route of transmission to prevent hepatitis C transmission in the future.
Methods:
A retrospective study of the outpatients and health care workers (n = 7,285) in the target outpatient clinic during 2011-2012 was conducted. The history of the study population infection with hepatitis C, electronic medical records, field visits, and health care worker interviews were examined for the period between March 1>st , 2006 and March 25th , 2016. The blood samples were collected and tested for anti-HCV antibodies, HCV RNA and HCV gene in 2016.
Results:
The rate of anti-HCV positive results was 4.4% in the study population. The risk factors associated with an anti-HCV positive result were ≥ 10 clinic visits, and receiving an invasive procedure including a nerve block and a block of the peripheral branch of the spinal nerve (p < 0.05). There were 112 HCV RNA positive cases out of 320 anti-HCV positive test result cases, amongst which 100 cases had the dominant HCV genotype 2a which formed either 1 cluster (n = 56) or 2 clusters (n = 25). This result indicated exposure to a high-association infection source.
Conclusion
Anti-HCV antibodies and genotypic analysis showed an epidemiological association between the outbreak of HCV and invasive procedures performed (2011-2012) at an outpatients clinic in Seoul.
6.Changes in the Eradication Efficacy of Fluoroquinolone-containing Triple Therapy for Helicobacter pylori Infection in Korea
Jung Won LEE ; Nayoung KIM ; Geun KIM ; Siho KIM ; Hwawon NAM ; Siwon LEE ; Cheol Min SHIN ; Young Soo PARK ; Dong Ho LEE
The Korean Journal of Helicobacter and Upper Gastrointestinal Research 2020;20(2):153-158
Background/Aims:
Fluoroquinolone-containing triple eradication therapy could be considered an alternative regimen for the second- line treatment of Helicobacter pylori infection. This study aimed to investigate the changes in the eradication efficacy of fluoroquinolone- containing triple therapy from 2003 to 2018 in Korea.
Materials and Methods:
Patients with a history of first-line eradication therapy failure were consecutively enrolled at Seoul National University Bundang Hospital from 2003 to 2018. All patients took moxifloxacin-containing triple therapy as the second-line eradication therapy. The treatment regimen comprised a three-drug combination comprising a proton pump inhibitor, amoxicillin, and moxifloxacin. Data on age, sex, endoscopic diagnosis, eradication results, compliance, and adverse outcomes were acquired and analyzed.
Results:
In total, 824 participants were enrolled during the study period, of whom, 46 were lost to follow-up. Finally, 778 participants were included in the per-protocol (PP) analysis, of whom, 72.1% received moxifloxacin-containing triple therapy for 14 days. The eradication rate of moxifloxacin-containing triple therapy was 72.1% (594/824) in the intention-to-treat analysis and 76.3% (594/778) in the PP analysis. A decline in eradication efficacy was observed, especially in the PP analysis (P=0.046). Diarrhea was the most commonly observed adverse event, accounting for 19.6% (41/209) of recorded adverse events.
Conclusions
Moxifloxacin-containing triple therapy has shown suboptimal eradication efficacy as the second-line eradication therapy. In addition, there is a concern that eradication rate will decrease due to increase in antimicrobial resistance.
7.Brain Diffusion Tensor MR Imaging.
Hyun Jeong KIM ; Choong Gon CHOI ; Jeong Hyun LEE ; Po Song YANG ; Siwon KANG ; Yeon Soo LEE ; Ji Chang KIM ; Bo Seal HWANG
Journal of the Korean Radiological Society 2005;53(4):233-243
The development of MR imaging techniques during the past decade has enabled researchers to use MR imaging as a noninvasive tool for evaluating structural and physiologic states in biologic tissues by measuring the diffusion process of water molecules. More recently, diffusion tensor MR imaging (DTI) technique based on the dependency of molecular diffusion on the orientation of white matter fiber tracts has been used to analyze the trajectory, shape, fiber structure, location, topology and connectivity of neuronal fiber pathways in living humans. Numerous efforts have been made by MR physicists, brain scientists, and medical doctors to advance MR techniques and computer-based algorithms which result in more accurate quantification of diffusion tensor and the generation of white matter fiber tract maps and to determine the pathophysiology of brain disease by DTI and useful clinical applications of DTI. In this article, we describe the tensor theory used to characterize molecular diffusion in white matter and a process of measuring tensor elements using diffusion-sensitive MR images to fiber mapping. We then provide review of current literature and some clinical examples that have been published and are on-going.
Brain Diseases
;
Brain*
;
Diffusion*
;
Humans
;
Magnetic Resonance Imaging*
;
Neurons
8.Surgical Correction of Left Ventricular Assist Device Outflow Graft Obstruction Caused by a Wrapped Expanded Polytetrafluoroethylene Graft: A Case Report
Sung Min KIM ; Ilkun PARK ; Siwon OH ; Hyo Won SEO ; Ga Hee JEONG ; Jun Ho LEE ; Su Ryeun CHUNG ; Kiick SUNG ; Wook Sung KIM ; Yang Hyun CHO
Journal of Chest Surgery 2024;57(4):413-417
A 70-year-old man with dilated cardiomyopathy underwent left ventricular assist device (LVAD) implantation, using a HeartWare ventricular assist device, as a bridge to candidacy.After 26 months, computed tomography (CT) angiography indicated stenosis in the LVAD outflow graft; however, the patient was asymptomatic, prompting a decision to manage his condition with close monitoring. Ten months later, the patient presented with dizziness and low-flow alerts. Subsequent CT angiography revealed a critical obstruction involving the entire LVAD outflow graft. The patient underwent emergency surgery, during which an organized seroma causing the graft obstruction was found between a wrapped expanded polytetrafluoroethylene (ePTFE) graft and a Dacron outflow graft. The covering of the outflow graft was removed, along with the organized seroma. Following removal of the ePTFE wrap and decompression of the outflow graft, normal LVAD flow was reestablished.The practice of wrapping the outflow graft with synthetic material, commonly done to facilitate later redo sternotomy, may pose a risk for outflow graft obstruction.
9.Surgical Correction of Left Ventricular Assist Device Outflow Graft Obstruction Caused by a Wrapped Expanded Polytetrafluoroethylene Graft: A Case Report
Sung Min KIM ; Ilkun PARK ; Siwon OH ; Hyo Won SEO ; Ga Hee JEONG ; Jun Ho LEE ; Su Ryeun CHUNG ; Kiick SUNG ; Wook Sung KIM ; Yang Hyun CHO
Journal of Chest Surgery 2024;57(4):413-417
A 70-year-old man with dilated cardiomyopathy underwent left ventricular assist device (LVAD) implantation, using a HeartWare ventricular assist device, as a bridge to candidacy.After 26 months, computed tomography (CT) angiography indicated stenosis in the LVAD outflow graft; however, the patient was asymptomatic, prompting a decision to manage his condition with close monitoring. Ten months later, the patient presented with dizziness and low-flow alerts. Subsequent CT angiography revealed a critical obstruction involving the entire LVAD outflow graft. The patient underwent emergency surgery, during which an organized seroma causing the graft obstruction was found between a wrapped expanded polytetrafluoroethylene (ePTFE) graft and a Dacron outflow graft. The covering of the outflow graft was removed, along with the organized seroma. Following removal of the ePTFE wrap and decompression of the outflow graft, normal LVAD flow was reestablished.The practice of wrapping the outflow graft with synthetic material, commonly done to facilitate later redo sternotomy, may pose a risk for outflow graft obstruction.
10.Surgical Correction of Left Ventricular Assist Device Outflow Graft Obstruction Caused by a Wrapped Expanded Polytetrafluoroethylene Graft: A Case Report
Sung Min KIM ; Ilkun PARK ; Siwon OH ; Hyo Won SEO ; Ga Hee JEONG ; Jun Ho LEE ; Su Ryeun CHUNG ; Kiick SUNG ; Wook Sung KIM ; Yang Hyun CHO
Journal of Chest Surgery 2024;57(4):413-417
A 70-year-old man with dilated cardiomyopathy underwent left ventricular assist device (LVAD) implantation, using a HeartWare ventricular assist device, as a bridge to candidacy.After 26 months, computed tomography (CT) angiography indicated stenosis in the LVAD outflow graft; however, the patient was asymptomatic, prompting a decision to manage his condition with close monitoring. Ten months later, the patient presented with dizziness and low-flow alerts. Subsequent CT angiography revealed a critical obstruction involving the entire LVAD outflow graft. The patient underwent emergency surgery, during which an organized seroma causing the graft obstruction was found between a wrapped expanded polytetrafluoroethylene (ePTFE) graft and a Dacron outflow graft. The covering of the outflow graft was removed, along with the organized seroma. Following removal of the ePTFE wrap and decompression of the outflow graft, normal LVAD flow was reestablished.The practice of wrapping the outflow graft with synthetic material, commonly done to facilitate later redo sternotomy, may pose a risk for outflow graft obstruction.