Publications by authors named "Ji Hoon Kim"

767 Publications

Crash Analysis of Aluminum/CFRP Hybrid Adhesive Joint Parts Using Adhesive Modeling Technique Based on the Fracture Mechanics.

Polymers (Basel) 2021 Sep 30;13(19). Epub 2021 Sep 30.

Department of Mechanical Engineering, Pusan National University, Pusan 46241, Korea.

This study describes the numerical simulation results of aluminum/carbon-fiber-reinforced plastic (CFRP) hybrid joint parts using the explicit finite-element solver LS-DYNA, with a focus on capturing the failure behavior of composite laminates as well as the adhesive capacity of the aluminum-composite interface. In this study, two types of adhesive modeling techniques were investigated: a tiebreak contact condition and a cohesive zone model. Adhesive modeling techniques have been adopted as a widely commercialized model of structural adhesives to simulate adhesive failure based on fracture mechanics. CFRP was studied with numerical simulations utilizing LS-DYNA MAT54 to analyze the crash capability of aluminum/CFRP. To evaluate the simulation model, the results were compared with the force-displacement curve from numerical analysis and experimental results. A parametric study was conducted to evaluate the effect of different fracture toughness values used by designers to predict crash capability and adhesive failure of aluminum/CFRP parts.
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http://dx.doi.org/10.3390/polym13193364DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8512440PMC
September 2021

Three-Dimensional Volumetric Measurement of Endolymphatic Hydrops in Meniere's Disease.

Front Neurol 2021 13;12:710422. Epub 2021 Sep 13.

Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, South Korea.

We used volumetric three-dimensional (3D) analysis to quantitatively evaluate the extent of endolymphatic hydrops (EH) in the entire inner ear. We tested for correlations between the planimetric and volumetric measurements, to identify their advantages and disadvantages. HYDROPS2-Mi2 EH images were acquired for 32 ears (16 patients): 16 ipsilateral ears of MD patients (MD-ears) and 16 contralateral ears. Three-T MR unit with a 32-channel phased-array coil/the contrast agent to fill the perilymphatic space and the HYDROPS2-Mi2 sequence. We calculated the EH% [(endolymph)/(endolymph+perilymph)] ratio and analyzed the entire inner ear in terms of the volumetric EH% value, but only single cochlear and vestibular slices were subjected to planimetric EH% evaluation. The EH% values were compared between MD ears and non-MD ears, to evaluate the diagnostic accuracy of the two methods. The volumetric EH% was significantly higher for MD vestibules (50.76 ± 13.78%) than non-MD vestibules (39.50 ± 8.99%). The planimetric EH% was also significantly higher for MD vestibules (61.98 ± 20.65%) than non-MD vestibules (37.22 ± 12.95%). The vestibular and cochlear volumetric EH% values correlated significantly with the planimetric EH% values of the MD ear. Volumetric and planimetric EH measurements facilitate diagnosis of MD ears compared to non-MD ears. Both methods seem to be reliable and consistent; the measurements were significantly correlated in this study. However, the planimetric EH% overestimates the extent of vestibular hydrops by 26.26%. Also, planimetric data may not correlate with volumetric data for non-MD cochleae with normal EH% values.
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http://dx.doi.org/10.3389/fneur.2021.710422DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8473889PMC
September 2021

Vivaldi Antenna Arrays Feed by Frequency-Independent Phase Shifter for High Directivity and Gain Used in Microwave Sensing and Communication Applications.

Sensors (Basel) 2021 Sep 11;21(18). Epub 2021 Sep 11.

Department of Information and Communication Engineering, Chosun University, 375 Susuk-dong, Dong-gu, Gwangju 501-759, Korea.

This paper describes a novel feed system for compact, wideband, high gain six-slot Vivaldi antenna arrays on a single substrate layer using a unique combination of power splitters based on binary T-junction power splitter topology, frequency-independent phase shifter, and a T-branch. The proposed antenna system consists of six Vivaldi antennas, three on the left, and three on the right arm. Each arm connects with T-junction power divider splitter topology, given that the right arm is linked through a frequency-independent phase shifter. Phase shifters ensure that the beam is symmetrical without splitting in a radiating plane so that highly directive radiation patterns occur. The optimal return losses (S-parameters) are well enriched by reforming Vivaldi's feeding arms and optimizing Vivaldi slots and feeds. A novel feature of our design is that the antenna exhibits the arrangements of a T-junction power splitter with an out-of-phase feeding mechanism in one of the arms, followed by a T-branching feeding to even arrays of proper Vivaldi antenna arrangement contributing high realized gain and front-to-back ratio up to 14.12 dBi and 23.23 dB respectively applicable for not only ultra-wideband (UWB) application, also for sensing and position detecting. The high directivity over the entire UWB frequency band in both higher and lower frequency ranges ensures that the antenna can be used in microwave through-wall imaging along with resolution imaging for ground penetration radar (GPR) applications. The fabricated antenna parameters are in close agreement with the simulated and measured results and are deployed for the detection of targets inside the voids of the concrete brick.
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http://dx.doi.org/10.3390/s21186091DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8472483PMC
September 2021

Trends in the Incidence and Survival Rates of Colorectal Signet-Ring Cell Carcinoma in the South Korean Population: Analysis of the Korea Central Cancer Registry Database.

J Clin Med 2021 Sep 20;10(18). Epub 2021 Sep 20.

Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju 26426, Korea.

Objective: Signet-ring cell carcinoma (SRCC) is a rare histopathological subtype of colorectal cancer (CRC) constituting approximately 1% of CRC cases. This study analyzed the incidence and survival rates of colorectal SRCC.

Methods: We analyzed the incidence and survival rates of colorectal SRCCs based on patients' data of the Korea Central Cancer Registry.

Results: The age-standardized incidence rates of colon and rectum SRCC in 2017 were 0.17 and 0.07 individuals per 100,000, respectively. Between 1993 and 2017, the 1-, 2-, 3-, 4-, and 5-year relative survival rates of patients with colon SRCC were 65.6%, 49.0%, 38.9%, 34.9%, and 33.0%, respectively, while those of patients with rectum SRCC were 69.6%, 47.8%, 38.5%, 32.8%, and 29.4%, respectively. According to the Surveillance, Epidemiology, and End Results summary stages, the 5-year relative survival rates of colon SRCC between 1993 and 2017 were 70.4% for the localized stage, 41.0% for the regional stage, and 7.0% for the distant stage, while those for rectum SRCC were 60.7%, 34.4, and 3.3%, respectively.

Conclusions: Although the incidence of colorectal SRCC is extremely low in South Korea, it has been increasing in recent decades. As the prognosis of colorectal SRCC is extremely poor; clinicians should be aware of the differential diagnosis of SRCC in colorectal cancer cases.
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http://dx.doi.org/10.3390/jcm10184258DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8468145PMC
September 2021

Update on liver disease management during the pandemic of coronavirus disease 2019 (COVID-19): 2021 KASL guideline.

Clin Mol Hepatol 2021 Oct 17;27(4):515-523. Epub 2021 Sep 17.

Department of Internal Medicine, Guro Hospital, Korea University College of Medicine, Seoul, Korea.

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http://dx.doi.org/10.3350/cmh.2021.0293DOI Listing
October 2021

Bioassay-Guided Isolation of Two Eudesmane Sesquiterpenes from Using Centrifugal Partition Chromatography.

Molecules 2021 Aug 30;26(17). Epub 2021 Aug 30.

College of Pharmacy, Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan 15588, Korea.

In this study, a centrifugal partition chromatography (CPC) separation was applied to identify antioxidant-responsive element (ARE) induction molecules from the crude extract of roots. CPC was operated with a two-phase solvent system composed of -hexane-methanol-water (10:8.5:1.5, //) in dual mode (descending to ascending), which provided a high recovery rate (>95.5%) with high resolution. Then, ARE induction activity of obtained CPC fractions was examined in ARE-transfected HepG2 cells according to the weight ratios of the obtained fractions. The fraction exhibiting ARE-inducing activity was further purified by preparative HPLC that led to isolation of two eudesmane type sesquiterpenes as active compounds. The chemical structures were elucidated as linderolide U () and a new sesquiterpene named as linderolide V () by spectroscopic data. Further bioactivity test demonstrated that compounds and enhanced ARE activity by 22.4-fold and 7.6-fold, respectively, at 100 μM concentration while 5 μM of sulforaphane induced ARE activity 24.8-fold compared to the control.
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http://dx.doi.org/10.3390/molecules26175269DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8433645PMC
August 2021

Highly conductive and elastic nanomembrane for skin electronics.

Science 2021 08;373(6558):1022-1026

School of Mechanical Engineering, Pusan National University, Busan 46241, Republic of Korea.

Skin electronics require stretchable conductors that satisfy metallike conductivity, high stretchability, ultrathin thickness, and facile patternability, but achieving these characteristics simultaneously is challenging. We present a float assembly method to fabricate a nanomembrane that meets all these requirements. The method enables a compact assembly of nanomaterials at the water-oil interface and their partial embedment in an ultrathin elastomer membrane, which can distribute the applied strain in the elastomer membrane and thus lead to a high elasticity even with the high loading of the nanomaterials. Furthermore, the structure allows cold welding and bilayer stacking, resulting in high conductivity. These properties are preserved even after high-resolution patterning by using photolithography. A multifunctional epidermal sensor array can be fabricated with the patterned nanomembranes.
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http://dx.doi.org/10.1126/science.abh4357DOI Listing
August 2021

Addition of V-Stage to Conventional TNM Staging to Create the TNVM Staging System for Accurate Prediction of Prognosis in Colon Cancer: A Multi-Institutional Retrospective Cohort Study.

Biomedicines 2021 Jul 25;9(8). Epub 2021 Jul 25.

Department of Surgery, Division of Colorectal Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.

We evaluated the prognostic impact of vascular invasion (VI) compared with nodal (N) stage and developed a new staging system including VI in colon cancer. Patients who underwent curative resection with stage II-III colon cancer were assigned to VI and non-VI groups; the latter was subclassified as N0, N1, and N2; a new TNVM staging was devised by adding the V-stage. Among the 2243 study participants, the VI group independently showed worse oncological outcomes than the N1 group (disease-free survival (DFS), hazard-ratio (HR) 1.704, 1.267-2.291; overall survival (OS), HR 2.301, 1.582-3.348). The 5-year DFS in the VI group was 63.4% [N1b (74.6%), = 0.003; N2a (69.7%), = 0.126; and N2b (56.8%), = 0.276], and the 5-year OS was 76.6% [N1b (84.9%), = 0.004; N2a (83.0%), = 0.047; and N2b (76.1%), = 0.906]. Thus, we considered VI as N2a in TNVM staging; 78 patients (3.5%) underwent upstaging. The 5-year OS rates of stage IIB and IIC increased from 88.6% and 65.9% in TNM staging to 90.5% and 85.7% in TNVM staging, respectively. In stage II-III colon cancer, VI had a similar prognostic impact as the N2 stage without VI. The incorporation of the V-stage into the conventional TNM staging facilitates better prediction of prognosis.
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http://dx.doi.org/10.3390/biomedicines9080888DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8389700PMC
July 2021

Predictive model for diagnosing central lesions in emergency department patients with isolated dizziness who undergo diffusion-weighted magnetic resonance imaging.

Acad Emerg Med 2021 Aug 20. Epub 2021 Aug 20.

Department of Emergency Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.

Objectives: Only 5% to 10% of patients who visit the emergency department (ED) with isolated dizziness without neurologic abnormalities may have central lesions; however, it is important to distinguish central lesions through brain imaging. This study was conducted to create a nomogram to provide an objective medical basis for selectively performing magnetic resonance imaging (MRI) among patients with isolated dizziness.

Methods: This retrospective observational study enrolled patients who visited the ED of a tertiary hospital with isolated dizziness and underwent diffusion-weighted MRI and subsequently consulted with the departments of neurology, neurosurgery, or otorhinolaryngology. Multivariable logistic regression analysis was performed to identify risk factors in patients diagnosed with central lesions to create a nomogram with the significant variables.

Results: Of the 1,078 patients who were screened, 119 were diagnosed with central lesions. Significant variables in the multivariable logistic regression analysis were albumin levels (odds ratio [OR] = 0.339, 95% confidence interval [CI] = 0.188 to 0.610, p = 0.0003), inorganic phosphate levels (OR = 0.891, 95% CI = 0.832 to 0.954, p = 0.0010), history of ischemic stroke (OR = 3.170, 95% CI = 1.807 to 5.560, p < 0.0001), presyncope (OR = 3.152, 95% CI = 1.184 to 8.389, p = 0.0216), and nystagmus (OR = 0.365, 95% CI = 0.237 to 0.561, p < 0.0001). The area under the receiver operating characteristic curve of the nomogram created with these variables was 0.7315 (95% CI = 0.6842 to 0.7788, p < 0.0001).

Conclusions: Albumin, inorganic phosphate, previous stroke, presyncope, and nystagmus were associated with the predictive diagnosis of central lesions among patients admitted to the ED with isolated dizziness. The novel nomogram created using these variables can help in objectively determining the need for MRI in patients presenting with isolated dizziness to the ED.
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http://dx.doi.org/10.1111/acem.14352DOI Listing
August 2021

Molecular mechanism underlying the apoptotic modulation by ethanol extract of Pseudolarix kaempferi in mucoepidermoid carcinoma of the salivary glands.

Cancer Cell Int 2021 Aug 14;21(1):427. Epub 2021 Aug 14.

Department of Oral Pathology, School of Dentistry and Dental Research Institute, Seoul National University, 03080, Seoul, Republic of Korea.

Background: Pseudolarix kaempferi is a traditional Chinese natural product that possesses the potential cytotoxic effects against cancer. However, the precise molecular mechanism underlying its cytotoxic effects has not yet been completely elucidated. Here, we clarify the mechanism via which the ethanol extract of P. kaempferi (EEPK) leads to cytotoxicity mediated by apoptosis in mucoepidermoid carcinoma (MEC) originating from the salivary glands.

Methods: We investigated the mechanism underlying the anticancer efficacy of EEPK in human MEC in vitro by assessing mitochondrial dysfunction, mRNA levels, and morphological changes in apoptotic cell nuclei as well as by using a cytotoxicity assay, flow cytometric analysis, and western blotting.

Results: EEPK inhibited the growth of two human MEC cells and stimulated the induction of caspase-mediated apoptosis that was accompanied by mitochondrial membrane depolarization. Compared with the vehicle control groups, EEPK decreased myeloid cell leukemia-1 (Mcl-1) expression in both cells whereas it significantly decreased B cell lymphoma-2 (Bcl-2) expression in MC3 cells only. The EEPK-induced altered Mcl-1 expression was caused by translational inhibition and proteasomal degradation. Additionally, EEPK significantly increased p-Bcl-2 (Ser) expression regardless of its total forms by facilitating the activation of the c-Jun N-terminal kinase (JNK) signaling pathway, which exhibited cell context dependency. Nevertheless, JNK activation following EEPK treatment was, at least in part, required for the proapoptotic efficacy of EEPK in both cells.

Conclusions: This study revealed that EEPK-induced alterations of Mcl-1 inhibition and JNK/Bcl-2 phosphorylation cause apoptosis and provided basic preclinical data for future clinical trials regarding therapy for patients with MEC.
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http://dx.doi.org/10.1186/s12935-021-02134-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8364062PMC
August 2021

Radiofrequency Ablation of Benign Thyroid Nodules: Recommendations from the Asian Conference on Tumor Ablation Task Force - Secondary Publication.

J Med Ultrasound 2021 Apr-Jun;29(2):77-83. Epub 2021 Jun 21.

Department of Ultrasound, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China.

Radiofrequency ablation (RFA) is a thermal ablation technique widely used for the management of benign thyroid nodules. To date, five academic societies in various countries have reported clinical practice guidelines, opinion statements, or recommendations regarding the use of thyroid RFA. However, despite some similarities, there are also differences among the guidelines, and a consensus is required regarding safe and effective treatment in Asian countries. Therefore, a task force was organized by the guideline committee of the Asian Conference on Tumor Ablation with the goal of devising recommendations for the clinical use of thyroid RFA. The recommendations in this article are based on a comprehensive analysis of the current literature and the consensus opinion of the task force members.
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http://dx.doi.org/10.4103/JMU.JMU_178_20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8330684PMC
June 2021

Age- and sex-specific risk of colorectal cancer in incident ulcerative colitis during the first 10 years after diagnosis: a nationwide population-based study.

Scand J Gastroenterol 2021 Aug 10:1-7. Epub 2021 Aug 10.

Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.

Objective: We assessed the risk of colorectal cancer (CRC) in patients with ulcerative colitis (UC) using the nationwide population-based claims data.

Materials And Methods: We analyzed the claims data of the Korean National Health Insurance (2006-2015). UC and CRC were defined using ICD-10 codes and UC-specific prescriptions in this study. Age- and sex-matched individuals without UC were randomly selected from the general population. Hazard ratios (HRs), adjusted for different covariates, were calculated using multivariate Cox proportional hazard regression.

Results: In total, 30,546 and 88,829 individuals with and without UC, respectively, were enrolled. CRC developed in 85 (0.27%) among UC, and 340 (0.38%) among individuals without UC, respectively. The HR (95% confidence interval [CI]) of CRC in all UC patients was 0.74 (0.58-0.94). Further, UC patients were stratified according to sex (male vs. female: 0.60 [0.44-0.82] vs. 1.10 [0.75-1.61]) and age (HR = 14.37, 2.74, 0.58, and 0.70 for 0-19, 20-39, 40-59, and ≥60 years, respectively). HR was significantly higher for late-onset UC (≥60 years) than for early-onset UC (0-19 years). The long duration of 5-aminosalicylic acid use had a significantly low HR, with reference to the 1st quartile.

Conclusions: The risk of CRC varies with age and sex in Korean patients with UC during the first decade after diagnosis. Early-onset UC (<40 years) increases the CRC risk.
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http://dx.doi.org/10.1080/00365521.2021.1958370DOI Listing
August 2021

agglutinin-reactive fraction of alpha-fetoprotein improves diagnostic accuracy for hepatocellular carcinoma.

World J Gastroenterol 2021 Jul;27(28):4687-4696

Department of Internal Medicine, Korea University College of Medicine, Seoul 02841, South Korea.

Background: Diagnostic accuracy of various tumor markers and their combinations for hepatocellular carcinoma (HCC) was not fully investigated.

Aim: To evaluate the diagnostic accuracy of alpha-fetoprotein (AFP), the agglutinin-reactive fraction of AFP (AFP-L3), and protein induced by vitamin K absence or antagonist-II (PIVKA-II) and their combination for HCC diagnosis.

Methods: Patients with newly detected liver mass or elevated serum AFP levels were considered eligible. Serum AFP level, AFP-L3 fraction, and PIVKA-II level were measured at the first visit.

Results: In total, 622 patients were included; 355 patients (57.1%) had chronic liver disease, and 208 (33.4%) had liver cirrhosis. HCC was diagnosed in 160 patients (25.7%). The area under the receiver operating characteristics curves (AUROCs) of the serum AFP, AFP-L3 fraction, AFP-L3, and PIVKA-II levels for the diagnosis of HCC were 0.775, 0.792, 0.814, and 0.834, respectively. A novel diagnostic model was developed by classifying patients in a 1:1 ratio into training and validation sets. Using the binary regression analysis of the training cohort, the AFP, AFP-L3 fraction, and PIVKA-II (ALPs) score was calculated as follows: ALPs score = 3.8 × [serum AFP level (ng/mL) × AFP-L3 fraction (%) × 0.01] + 0.2 × PIVKA-II level (mAU/mL). The AUROC of the ALPs score for diagnosis of HCC was 0.878, significantly higher than that of serum AFP level ( < 0.001), AFP-L3 fraction ( < 0.001), PIVKA-II level ( = 0.036), and AFP-L3 level ( = 0.006). The optimal ALPs score cut-off was 5.3 (sensitivity, 85.0%, specificity 80.1%). The validation cohort showed similar results.

Conclusion: The ALPs score calculated using serum AFP level, AFP-L3 fraction, and PIVKA-II level showed improved accuracy in HCC diagnosis.
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http://dx.doi.org/10.3748/wjg.v27.i28.4687DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8326250PMC
July 2021

The impact of the abnormal salinity enrichment in pore water on the thermodynamic stability of marine natural gas hydrates in the Arctic region.

Sci Total Environ 2021 Dec 30;799:149357. Epub 2021 Jul 30.

Department of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulju-gun, Ulsan 44919, Republic of Korea. Electronic address:

In this study, the thermodynamic and structural characteristics of natural gas hydrates (NGHs) retrieved from gas hydrate mounds (ARAON Mound 03 (AM03) and ARAON Mound 06 (AM06)) in the Chukchi Sea in the Arctic region were investigated. The gas compositions, crystalline structure, and cage occupancy of the NGHs at AM03 and AM06 were experimentally measured using gas chromatography (GC), C nuclear magnetic resonance (NMR), Raman spectroscopy, and powder X-ray diffraction (PXRD). In the NGHs from AM03 and AM06, a significantly large fraction of CH (> 99%) and a very small amount of HS were enclathrated in small (5) and large (56) cages of sI hydrate. The NGHs from AM03 and AM06 were almost identical in composition, guest distributions, and existing environment to each other. The salinity of the residual pore water in the hydrate-bearing sediment (AM06) was measured to be 50.32‰, which was much higher than that of seawater (34.88‰). This abnormal salinity enrichment in the pore water of the low-permeability sediment might induce the dissociation of NGHs at a lower temperature than expected. The saturation changes in the NGHs that corresponded with an increase in the seawater temperature were also predicted on the basis of the salinity changes in the pore water. The experimental and predicted results of this study would be helpful for understanding the thermodynamic stability of NGHs and potential CH-releasing phenomena in the Arctic region.
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http://dx.doi.org/10.1016/j.scitotenv.2021.149357DOI Listing
December 2021

Evaluation of the severity of nonalcoholic fatty liver disease through analysis of serum exosomal miRNA expression.

PLoS One 2021 6;16(8):e0255822. Epub 2021 Aug 6.

Department of Internal Medicine, Korea University College of Medicine, Seoul, South Korea.

Noninvasive techniques for evaluating the severity of nonalcoholic fatty liver disease (NAFLD) have shown limited diagnostic performance. MicroRNAs (miRNAs) are useful biomarkers for diagnosing and monitoring the progression and treatment response to several diseases. Here, we evaluated whether serum exosomal miRNAs could be used for the diagnosis and prognosis of NAFLD severity. Exosomal miRNAs were isolated from the sera of 41 patients with NAFLD (diagnosed using liver biopsy) for microarray profiling. The degree of NAFLD severity was determined using inflammation, steatosis, and ballooning scores and the NAFLD activity score (NAS). Correlations between miRNA expression, clinical and biochemical parameters, and mRNA expression were analyzed. Overall, 25, 11, 13, and 14 miRNAs correlated with the inflammation score, steatosis score, ballooning score, and NAS, respectively, with 33 significant correlations observed between 27 miRNAs and six clinical variables. Eight miRNAs (let-7b-5p, miR-378h, -1184, -3613-3p, -877-5p, -602, -133b, and 509-3p) showed anticorrelated patterns with the corresponding mRNA expression. In fibrosis, 52 and 30 interactions corresponding to high miRNA-low mRNA and low miRNA-high mRNA expression, respectively, were observed. The present results therefore suggest that serum exosomal miRNAs can be used to evaluate NAFLD severity and identify potential targets for NAFLD treatment.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0255822PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8345824PMC
August 2021

Incidence and survival rates of lymphoepithelioma-like gastric carcinoma: analysis of the Korea Central Cancer Registry Database.

Scand J Gastroenterol 2021 Oct 1;56(10):1182-1186. Epub 2021 Aug 1.

Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.

Background: Lymphoepithelial carcinoma of the stomach (LEGC) is a rare type of gastric carcinoma. There is a limited understanding of the incidence and survival rates of LEGC. The aim was to investigate the nationwide incidence and survival rates of LEGC in Korea using the Korea Central Cancer Registry.

Methods: The data on LEGC were retrieved from the Korea Central Cancer Registry of Korean Cancer Center. The age and sex of the patients and the Surveillance, Epidemiology, and End Results (SEER) summary stage of the tumor were analyzed, and the relative survival rates (RSRs) were calculated. The Korea Central Cancer Registry has data of patients with LEGC from 1993 to 2017 but is approved to use personal information only from 2006 to 2017 due to privacy restrictions of the institute. The RSRs, as calculated data, were able to be disclosed from 1993 to 2017.

Results: Between 2006 and 2017, the total number of LEGC was 1,030, and the trend of incidence increased ty time ( = .002). In the SEER stage, the proportion of localized stage was 54.3% in 2006, and 73.9% in 2017, which increased from 2006 to 2017 significantly ( = .002). The RSR was higher in men than in women. The cumulative 5-year RSRs were 98.0% in the localized stage and 88.0% in the regional stage during 1993-2017. The 5-year RSRs increased 79.5% in 1996-2000 to 93.4% in 2013-2017.

Conclusions: The incidence of LEGC is low, which has been increasing in recent years in South Korea. The prognosis of LEGC is good even at advanced stages and gets better as time goes by. Our findings provide useful insights to clinicians about LEGC and inform patients about the survival rate.
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http://dx.doi.org/10.1080/00365521.2021.1955966DOI Listing
October 2021

Combination of neuron-specific enolase measurement and initial neurological examination for the prediction of neurological outcomes after cardiac arrest.

Sci Rep 2021 07 23;11(1):15067. Epub 2021 Jul 23.

Department of Emergency Medicine, Chonnam National University, Chonnam National University Hospital, Gwangju, South Korea.

This study aimed to investigate the efficacy of the combination of neuron-specific enolase (NSE) measurement and initial neurological examination in predicting the neurological outcomes of patients with cardiac arrest (CA) by retrospectively analyzing data from the Korean Hypothermia Network prospective registry. NSE levels were recorded at 48 and 72 h after CA. The initial Full Outline of UnResponsiveness (FOUR) and Glasgow Coma Scale (GCS) scores were recorded. These variables were categorized using the scorecard method. The primary endpoint was poor neurological outcomes at 6 months. Of the 475 patients, 171 (36%) had good neurological outcomes at 6 months. The areas under the curve (AUCs) of the categorized NSE levels at 72 h, GCS score, and FOUR score were 0.889, 0.722, and 0.779, respectively. The AUCs of the combinations of categorized NSE levels at 72 h with categorized GCS scores and FOUR score were 0.910 and 0.912, respectively. Each combination was significantly higher than the AUC value of the categorized NSE level at 72 h alone (with GCS: p = 0.015; with FOUR: p = 0.026). Combining NSE measurement and initial neurological examination improved the prediction of neurological outcomes.
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http://dx.doi.org/10.1038/s41598-021-94555-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8302684PMC
July 2021

Circulating miRNA is a useful diagnostic biomarker for nonalcoholic steatohepatitis in nonalcoholic fatty liver disease.

Sci Rep 2021 07 19;11(1):14639. Epub 2021 Jul 19.

Department of Internal Medicine, Division of Gastroenterology and Hepatology, Guro Hospital, Korea University College of Medicine, Korea University Medical Center, 97, Guro-Dong Gil, Guro-Dong, Guro-Ku, Seoul, 08308, Republic of Korea.

Nonalcoholic steatohepatitis (NASH) is considered as a progressive form of nonalcoholic fatty liver disease (NAFLD). To distinguish NASH from nonalcoholic fatty liver (NAFL), we evaluated the diagnostic value of circulating miRNAs. Small RNA sequencing was performed on 12 NAFL patients and 12 NASH patients, and the miRNA expression was compared. After selecting miRNAs for the diagnosis of NASH, we analyzed the diagnostic accuracy of each miRNA and the combination of miRNAs. External validation was performed using quantitative reverse transcription PCR. Among the 2,588 miRNAs, 26 miRNAs significantly increased in the NASH group than in the NAFL group. Among the 26 elevated miRNAs in the NASH group, 8 miRNAs were selected, and in silico analysis was performed. Only four miRNAs (miR-21-5p, miR-151a-3p, miR-192-5p, and miR-4449) showed significant area under the receiver operating characteristic curve (AUC) values for NASH diagnosis. The combination of the four miRNAs showed satisfactory diagnostic accuracy for NASH (AUC 0.875; 95% CI 0.676-0.973). External validation revealed similar diagnostic accuracy for NASH (AUC 0.874; 95% CI 0.724-0.960). NASH represents significantly distinct miRNA expression profile compared with NAFL. The combination of serum circulating miRNAs can be used as a novel biomarker for the NASH diagnosis in NAFLD.
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http://dx.doi.org/10.1038/s41598-021-94115-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8289842PMC
July 2021

Prediction of Prognosis in Glioblastoma Using Radiomics Features of Dynamic Contrast-Enhanced MRI.

Korean J Radiol 2021 09 14;22(9):1514-1524. Epub 2021 Jul 14.

Department of Radiology, Seoul National University Hospital, Seoul, Korea.

Objective: To develop a radiomics risk score based on dynamic contrast-enhanced (DCE) MRI for prognosis prediction in patients with glioblastoma.

Materials And Methods: One hundred and fifty patients (92 male [61.3%]; mean age ± standard deviation, 60.5 ± 13.5 years) with glioblastoma who underwent preoperative MRI were enrolled in the study. Six hundred and forty-two radiomic features were extracted from volume transfer constant (K), fractional volume of vascular plasma space (V), and fractional volume of extravascular extracellular space (V) maps of DCE MRI, wherein the regions of interest were based on both T1-weighted contrast-enhancing areas and non-enhancing T2 hyperintense areas. Using feature selection algorithms, salient radiomic features were selected from the 642 features. Next, a radiomics risk score was developed using a weighted combination of the selected features in the discovery set (n = 105); the risk score was validated in the validation set (n = 45) by investigating the difference in prognosis between the "radiomics risk score" groups. Finally, multivariable Cox regression analysis for progression-free survival was performed using the radiomics risk score and clinical variables as covariates.

Results: 16 radiomic features obtained from non-enhancing T2 hyperintense areas were selected among the 642 features identified. The radiomics risk score was used to stratify high- and low-risk groups in both the discovery and validation sets (both < 0.001 by the log-rank test). The radiomics risk score and presence of isocitrate dehydrogenase (IDH) mutation showed independent associations with progression-free survival in opposite directions (hazard ratio, 3.56; = 0.004 and hazard ratio, 0.34; = 0.022, respectively).

Conclusion: We developed and validated the "radiomics risk score" from the features of DCE MRI based on non-enhancing T2 hyperintense areas for risk stratification of patients with glioblastoma. It was associated with progression-free survival independently of IDH mutation status.
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http://dx.doi.org/10.3348/kjr.2020.1433DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8390822PMC
September 2021

NTRK and RET fusion-directed therapy in pediatric thyroid cancer yields a tumor response and radioiodine uptake.

J Clin Invest 2021 Sep;131(18)

Genomic Medicine Institute, Medical Research Center, Seoul National University, Seoul, Republic of Korea.

BACKGROUNDMolecular characterization in pediatric papillary thyroid cancer (PTC), distinct from adult PTC, is important for developing molecularly targeted therapies for progressive radioiodine-refractory (131I-refractory) PTC.METHODSPTC samples from 106 pediatric patients (age range: 4.3-19.8 years; n = 84 girls, n = 22 boys) who were admitted to SNUH (January 1983-March 2020) were available for genomic profiling. Previous transcriptomic data from 125 adult PTC samples were used for comparison.RESULTSWe identified genetic drivers in 80 tumors: 31 with fusion oncogenes (RET in 21 patients, ALK in 6 patients, and NTRK1/3 in 4 patients); 47 with point mutations (BRAFV600E in 41 patients, TERTC228T in 2 patients [1 of whom had a coexisting BRAFV600E], and DICER1 variants in 5 patients); and 2 with amplifications. Fusion oncogene PTCs, which are predominantly detected in younger patients, were at a more advanced stage and showed more recurrent or persistent disease compared with BRAFV600E PTCs, which are detected mostly in adolescents. Pediatric fusion PTCs (in patients <10 years of age) had lower expression of thyroid differentiation genes, including SLC5A5, than did adult fusion PTCs. Two girls with progressive 131I-refractory lung metastases harboring a TPR-NTRK1 or CCDC6-RET fusion oncogene received fusion-targeted therapy; larotrectinib and selpercatinib decreased the size of the tumor and restored 125I radioiodine uptake. The girl with the CCDC6-RET fusion oncogene received 131I therapy combined with selpercatinib, resulting in a tumor response. In vitro 125I uptake and 131I clonogenic assays showed that larotrectinib inhibited tumor growth and restored radioiodine avidity.CONCLUSIONSIn pediatric patients with fusion oncogene PTC who have 131I-refractory advanced disease, selective fusion-directed therapy may restore radioiodine avidity and lead to a dramatic tumor response, underscoring the importance of molecular testing in pediatric patients with PTC.FUNDINGThe Ministry of Science, ICT and Future Planning (NRF-2016R1A2B4012417 and 2019R1A2C2084332); the Korean Ministry of Health and Welfare (H14C1277); the Ministry of Education (2020R1A6A1A03047972); and the SNUH Research Fund (04-2015-0830).TRIAL REGISTRATIONTwo patients received fusion-targeted therapy with larotrectinib (NCT02576431; NAVIGATE) or selpercatinib (LOXO-RET-18018).
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http://dx.doi.org/10.1172/JCI144847DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8439610PMC
September 2021

Contrast-enhanced MRI T1 Mapping for Quantitative Evaluation of Putative Dynamic Glymphatic Activity in the Human Brain in Sleep-Wake States.

Radiology 2021 09 22;300(3):661-668. Epub 2021 Jun 22.

From the Departments of Radiology (S.L., R.E.Y., S.H.C., J.Y.L., I.H., K.M.K., T.J.Y., J.H.K., C.H.S.) and Clinical Pharmacology and Therapeutics (K.Y.H.), Seoul National University Hospital, Seoul National University College of Medicine, 101 Daehangno, Jongno-gu, Seoul 03080, Republic of Korea; Center for Nanoparticle Research, Institute for Basic Science, Seoul, Republic of Korea (S.H.C.); School of Chemical and Biological Engineering (S.H.C.) and Department of Electrical and Computer Engineering (S.J., J.L.), Seoul National University, Seoul, Republic of Korea; and Department of Biomedical Engineering, Hankuk University of Foreign Studies, Yongin-si, Republic of Korea (S.H.O.).

Background Evaluation of the glymphatic system with intrathecal contrast material injection has limited clinical use. Purpose To investigate the feasibility of using serial intravenous contrast-enhanced T1 mapping in the quantitative evaluation of putative dynamic glymphatic activity in various brain regions and to demonstrate the effect of sleep on glymphatic activity in humans. Materials and Methods In this prospective study from May 2019 to February 2020, 25 healthy participants (mean age, 25 years ± 2 [standard deviation]; 15 men) underwent two cycles of MRI (day and night cycles). For each cycle, T1 maps were acquired at baseline and 0.5, 1, 1.5, 2, and 12 hours after intravenous contrast material injection. For the night cycle, participants had a normal night of sleep between 2 and 12 hours. The time () to reach the minimum T1 value (T1), the absolute difference between baseline T1 and T1 (peak ΔT1), and the slope between two measurements at 2 and 12 hours (slope) were determined from T1 value-time curves in cerebral gray matter (GM), cerebral white matter (WM), cerebellar GM, cerebellar WM, and putamen. Mixed-model analysis of variance (ANOVA), Friedman test, and repeated-measures ANOVA were used to assess the effect of sleep on slope and to compare and peak ΔT1 among different regions. Results The slope increased from the day to night cycles in cerebral GM, cerebellar GM, and putamen (geometric mean ratio [night/day] = 1.4 [95% CI: 1.2, 1.7], 1.3 [95% CI: 1.1, 1.4], and 2.4 [95% CI: 1.6, 3.6], respectively; = .001, < .001, and < .001, respectively). Median values were 0.5 hour in cerebral and cerebellar GM and putamen for both cycles. Cerebellar GM had the highest mean peak ΔT1, followed by cerebral GM and putamen in both day (159 msec ± 6, 99 msec ± 4, and 62 msec ± 5, respectively) and night (152 msec ± 6, 104 msec ± 6, and 58 msec ± 4, respectively) cycles. Conclusion Clearance of a gadolinium-based contrast agent was greater after sleep compared with daytime wakefulness. These results suggest that sleep was associated with greater glymphatic clearance compared with wakefulness. © RSNA, 2021 . See also the editorial by Anzai and Minoshima in this issue.
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http://dx.doi.org/10.1148/radiol.2021203784DOI Listing
September 2021

The authors reply.

Crit Care Med 2021 07;49(7):e731-e732

Department of Emergency Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.

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http://dx.doi.org/10.1097/CCM.0000000000005080DOI Listing
July 2021

Diagnostic Performance of the Modified Korean Thyroid Imaging Reporting and Data System for Thyroid Malignancy: A Multicenter Validation Study.

Korean J Radiol 2021 09 1;22(9):1579-1586. Epub 2021 Jun 1.

Department of Radiology and Research Institute of Radiology, Asian Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Objective: To evaluate the diagnostic performance of the modified Korean Thyroid Imaging Reporting and Data System (K-TIRADS), and compare it with the 2016 version of K-TIRADS using the Thyroid Imaging Network of Korea.

Materials And Methods: Between June and September 2015, 5708 thyroid nodules (≥ 1.0 cm) from 5081 consecutive patients who had undergone thyroid ultrasonography at 26 institutions were retrospectively evaluated. We used a biopsy size threshold of 2 cm for K-TIRADS 3 and 1 cm for K-TIRADS 4 (modified K-TIRADS 1) or 1.5 cm for K-TIRADS 4 (modified K-TIRADS 3). The modified K-TIRADS 2 subcategorized the K-TIRADS 4 into 4A and 4B, and the cutoff sizes for the biopsies were defined as 1 cm for K-TIRADS 4B and 1.5 cm for K-TIRADS 4A. The diagnostic performance and the rate of unnecessary biopsies of the modified K-TIRADS for detecting malignancy were compared with those of the 2016 K-TIRAD, which were stratified by nodule size (with a threshold of 2 cm).

Results: A total of 1111 malignant nodules and 4597 benign nodules were included. The sensitivity, specificity, and unnecessary biopsy rate of the benign nodules were 94.9%, 24.4%, and 60.9% for the 2016 K-TIRADS; 91.0%, 39.7%, and 48.6% for the modified K-TIRADS 1; 84.9%, 45.9%, and 43.5% for the modified K-TIRADS 2; and 76.1%, 50.2%, and 40.1% for the modified K-TIRADS 3. For small nodules (1-2 cm), the diagnostic sensitivity of the modified K-TIRADS decreased by 5.2-25.6% and the rate of unnecessary biopsies reduced by 19.2-32.8% compared with those of the 2016 K-TIRADS ( < 0.001). For large nodules (> 2 cm), the modified K-TIRADSs maintained a very high sensitivity for detecting malignancy (98%).

Conclusion: The modified K-TIRADSs significantly reduced the rate of unnecessary biopsies for small (1-2 cm) nodules while maintaining a very high sensitivity for malignancy for large (> 2 cm) nodules.
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http://dx.doi.org/10.3348/kjr.2021.0230DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8390813PMC
September 2021

Natural killer cell activity is a risk factor for the recurrence risk after curative treatment of hepatocellular carcinoma.

BMC Gastroenterol 2021 Jun 12;21(1):258. Epub 2021 Jun 12.

Department of Internal Medicine, Korea University College of Medicine, 73, Goryeodae-ro, Seongbuk-Gu, Seoul, Korea.

Background: Natural killer (NK) cells have been known to contribute to surveillance and control of hepatocellular carcinoma (HCC). However, the association of NK cell activity with stage and recurrence risk of HCC have not been fully evaluated.

Methods: Untreated patients with newly diagnosed HCC were prospectively enrolled. Peripheral blood mononuclear cells were isolated at the time of diagnosis. Patients who had undergone surgery or radiofrequency ablation were classified as the curative treatment group, and their blood samples were collected again at 1 month after treatment.

Results: A total of 80 patients with HCC were enrolled. The mean age was 62.5 years. At baseline, interferon (IFN)-γ producing NK cell proportion was significantly lower in patients with Barcelona clinic liver cancer (BCLC) stage B, C, or D than in those with BCLC stage 0 (42.9% vs. 56.8%, P = 0.045). Among all patients, 56 patients had undergone curative treatment, and 42 patients re-visited at 1 month after curative treatment. There was no significant change in total NK cell and IFN-γ producing NK cell proportion from baseline to 1 month after treatment (all P > 0.05). During a median follow-up of 12.4 months, HCC recurred in 14 patients (33.3%). When patients were classified according to the IFN-γ producing NK cell proportion (group 1, ≥ 45%; and group 2, < 45%), HCC recurrence rate did not differ according to the IFN-γ producing NK cell proportion at baseline (log-rank test, P = 0.835). However, patients with < 45% IFN-γ producing NK cell proportion at 1 month after treatment had a significantly higher HCC recurrence rate than patients with that of ≥ 45% (log-rank test, P < 0.001). Multivariate analysis revealed that BCLC stage B (hazard ratio [HR] = 3.412, P = 0.045) and < 45% IFN-γ producing NK cell proportion at 1 month after treatment (HR = 6.934, P = 0.001) independently predicted an increased risk of HCC recurrence.

Conclusions: Decreased NK cell activity is significantly associated with the advanced stage of HCC, and the increased recurrence risk of HCC after curative treatment.
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http://dx.doi.org/10.1186/s12876-021-01833-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8199695PMC
June 2021

Recent Developments of ICG-Guided Sentinel Lymph Node Mapping in Oral Cancer.

Diagnostics (Basel) 2021 May 17;11(5). Epub 2021 May 17.

Department of Otorhinolaryngology-Head and Neck Surgery, Soonchunhyang University College of Medicine, Seoul 04401, Korea.

Sentinel lymph node (SLN) biopsy has gained attention as a method of minimizing the extent of neck dissection with a similar survival rate as elective neck dissection in oral cancer. Indocyanine green (ICG) imaging is widely used in the field of surgical oncology. Real-time ICG-guided SLN imaging has been widely used in minimally invasive surgeries for various types of cancers. Here, we provide an overview of conventional SLN biopsy and ICG-guided SLN mapping techniques for oral cancer. Although ICG has many strengths, it still has limitations regarding its potential use as an ideal compound for SLN mapping. The development of novel fluorophores and imaging technology is needed for accurate identification of SLNs, which will allow precision surgery that would reduce morbidities and increase patient survival.
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http://dx.doi.org/10.3390/diagnostics11050891DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8156251PMC
May 2021

Efficacy and Safety of Glecaprevir/Pibrentasvir in Korean Patients with Chronic Hepatitis C: A Pooled Analysis of Five Phase II/III Trials.

Gut Liver 2021 Jun 2. Epub 2021 Jun 2.

Department of Internal Medicine, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Korea.

Background/aims: Glecaprevir/pibrentasvir (G/P) is the first pan-genotypic direct-acting antiviral combination therapy approved in Korea. An integrated analysis of five phase II and III trials was conducted to evaluate the efficacy and safety of G/P in Korean patients with chronic hepatitis C virus (HCV) infection.

Methods: The study analyzed pooled data on Korean patients with HCV infection enrolled in the ENDURANCE 1 and 2, SURVEYOR II part 4 and VOYAGE I and II trials, which evaluated the efficacy and safety of 8 or 12 weeks of G/P treatment. The patients were either treatment-naïve or had received sofosbuvir or interferon-based treatment. Efficacy was evaluated by assessing the rate of sustained virologic response at 12 weeks posttreatment (SVR12). Safety was evaluated by monitoring adverse events (AEs) and laboratory assessments.

Results: The analysis included 265 patients; 179 (67.5%) were HCV treatment-naïve, and most patients were either subgenotype 1B (48.7%) or 2A (44.5%). In the intention-to-treat population, 262 patients (98.9%) achieved SVR12. Three patients did not achieve SVR12: one had virologic failure and two had non-virologic failures. Most AEs were grade 1/2; eight patients (3.0%) experienced at least one grade ≥3 AE. No serious AEs related to G/P treatment were reported, and grade ≥3 hepatic laboratory abnormalities were rare (0.8%).

Conclusions: G/P therapy was highly efficacious and well tolerated in Korean patients with HCV infection, with most patients achieving SVR12. The safety profile was comparable to that observed in a pooled analysis of a global pan-genotypic population of patients with HCV infection who received G/P.
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http://dx.doi.org/10.5009/gnl20321DOI Listing
June 2021

Prediction of brain age from routine T2-weighted spin-echo brain magnetic resonance images with a deep convolutional neural network.

Neurobiol Aging 2021 09 28;105:78-85. Epub 2021 Apr 28.

Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea. Electronic address:

Our study investigated the feasibility and clinical relevance of brain age prediction using axial T2-weighted images (T2-WIs) with a deep convolutional neural network (CNN) algorithm. The CNN model was trained by 1,530 scans in our institution. The performance was evaluated by the mean absolute error (MAE) between the predicted brain age and the chronological age based on an internal test set (n=270) and an external test set (n=560). The ensemble CNN model showed an MAE of 4.22 years in the internal test set and 9.96 years in the external test set. Participants with grade 2-3 white matter hyperintensity (WMH) showed a higher corrected predicted age difference (PAD) than grade 0 WMH (posthoc p<0.001). Participants diagnosed with diabetes mellitus also had a higher corrected PAD than those without diabetes (adjusted p=0.048), although it showed no significant differences according to the diagnosis of hypertension or dyslipidemia. We suggest that routine clinical T2-WIs are feasible to predict brain age, and it might be clinically relevant according to the WMH grade and the presence of diabetes mellitus.
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http://dx.doi.org/10.1016/j.neurobiolaging.2021.04.015DOI Listing
September 2021

Preoperative Assessment of Renal Sinus Invasion by Renal Cell Carcinoma according to Tumor Complexity and Imaging Features in Patients Undergoing Radical Nephrectomy.

Korean J Radiol 2021 08 20;22(8):1323-1331. Epub 2021 May 20.

Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.

Objective: To identify the association between renal tumor complexity and pathologic renal sinus invasion (RSI) and evaluate the usefulness of computed tomography tumor features for predicting RSI in patients with renal cell carcinoma (RCC).

Materials And Methods: This retrospective study included 276 consecutive patients who underwent radical nephrectomy for RCC with a size of ≤ 7 cm between January 2014 and October 2017. Tumor complexity and anatomical renal sinus involvement were evaluated using two standardized scoring systems: the radius (R), exophytic or endophytic (E), nearness to collecting system or sinus (N), anterior or posterior (A), and location relative to polar lines (RENAL) nephrometry and preoperative aspects and dimensions used for anatomical classification (PADUA) system. CT-based tumor features, including shape, enhancement pattern, margin at the interface of the renal sinus (smooth vs. non-smooth), and finger-like projection of the mass, were also assessed by two independent radiologists. Univariable and multivariable logistic regression analyses were performed to identify significant predictors of RSI. The positive predictive value, negative predictive value (NPV), accuracy of anatomical renal sinus involvement, and tumor features were evaluated.

Results: Eighty-one of 276 patients (29.3%) demonstrated RSI. Among highly complex tumors (RENAL or PADUA score ≥ 10), the frequencies of RSI were 42.4% (39/92) and 38.0% (71/187) using RENAL and PADUA scores, respectively. Multivariable analysis showed that a non-smooth margin and the presence of a finger-like projection were significant predictors of RSI. Anatomical renal sinus involvement showed high NPVs (91.7% and 95.2%) but low accuracy (40.2% and 43.1%) for RSI, whereas the presence of a non-smooth margin or finger-like projection demonstrated comparably high NPVs (90.0% and 91.3% for both readers) and improved accuracy (67.0% and 73.9%, respectively).

Conclusion: A non-smooth margin or the presence of a finger-like projection can be used as a preoperative CT-based tumor feature for predicting RSI in patients with RCC.
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http://dx.doi.org/10.3348/kjr.2020.0984DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8316778PMC
August 2021

Author's Reply: Pure Laparoscopic Hepatectomy for Tumors Close to the Major Hepatic Veins: Intraparenchymal Identification of the Major Hepatic Veins using the Ventral Approach.

Authors:
Ji Hoon Kim

World J Surg 2021 09 19;45(9):2940. Epub 2021 May 19.

Center for Liver and Pancreatobiliary Cancer, National Cancer Center, 323 Ilsan-ro, Ilsandonggu, Goyang-si, Gyeonggi-do, 10408, Republic of Korea.

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http://dx.doi.org/10.1007/s00268-021-06179-0DOI Listing
September 2021

Differentiation between glioblastoma and primary CNS lymphoma: application of DCE-MRI parameters based on arterial input function obtained from DSC-MRI.

Eur Radiol 2021 May 18. Epub 2021 May 18.

Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea.

Objective: This study aimed to evaluate whether arterial input functions (AIFs) obtained from dynamic susceptibility contrast (DSC)-MRI (AIF) improve the reliability and diagnostic accuracy of dynamic contrast-enhanced (DCE)-derived pharmacokinetic (PK) parameters for differentiating glioblastoma from primary CNS lymphoma (PCNSL) compared with AIFs derived from DCE-MRI (AIF).

Methods: This retrospective study included 172 patients with glioblastoma (n = 147) and PCNSL (n = 25). All patients had undergone preoperative DSC- and DCE-MRI. The volume transfer constant (K), volume of the vascular plasma space (v), and volume of the extravascular extracellular space (v) were acquired using AIF and AIF. The relative cerebral blood volume (rCBV) was obtained from DSC-MRI. Intraclass correlation coefficients (ICC) and ROC curves were used to assess the reliability and diagnostic accuracy of individual parameters.

Results: The mean K, v, and v values revealed better ICCs with AIF than with AIF (K, 0.911 vs 0.355; v, 0.766 vs 0.503; v, 0.758 vs 0.657, respectively). For differentiating all glioblastomas from PCNSL, the mean rCBV (AUC = 0.856) was more accurate than the AIF-driven mean K, which had the largest AUC (0.711) among the DCE-derived parameters (p = 0.02). However, for glioblastomas with low rCBV (≤ 75th percentile of PCNSL; n = 30), the AIF-driven mean K and v were more accurate than rCBV (AUC: K, 0.807 vs rCBV, 0.515, p = 0.004; v, 0.715 vs rCBV, p = 0.045).

Conclusion: DCE-derived PK parameters using the AIF showed improved reliability and diagnostic accuracy for differentiating glioblastoma with low rCBV from PCNSL.

Key Points: • An accurate differential diagnosis of glioblastoma and PCNSL is crucial because of different therapeutic strategies. • In contrast to the rCBV from DSC-MRI, another perfusion imaging technique, the DCE parameters for the differential diagnosis have been limited because of the low reliability of AIFs from DCE-MRI. • When we analyzed DCE-MRI data using AIFs from DSC-MRI (AIF), AIF-driven DCE parameters showed improved reliability and better diagnostic accuracy than rCBV for differentiating glioblastoma with low rCBV from PCNSL.
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http://dx.doi.org/10.1007/s00330-021-08044-zDOI Listing
May 2021
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