113 research outputs found
Learning lives with/in digital media: Emergence of online economy disputants in the midst of economic crisis in South Korea
This study aims to understand adult online informal learning illuminating a way of becoming an influential social figure. We interviewed five famous online economy disputants whose postings were very popular in Korea during the global financial crisis in 2008-2009. We explored how they learned and found that their self-directedness interplayed with the context of other- directedness, a sense of being stimulated and indebted enhanced their learning process, and dynamics of anonymity and social recognition were keys to their emergence
N-terminal Pro-Brain Natriuretic Peptide Levels Predict Left Ventricular Systolic Function in Patients with Chronic Kidney Disease
N-terminal pro-brain natriuretic peptide (NT-proBNP) can be a useful marker for left ventricular (LV) dysfunction in patients without kidney disease. This study was conducted to clarify the relationship between NT-proBNP and LV systolic function in patients with decreased renal function. We studied 256 chronic kidney disease (CKD) patients, patients on dialysis were excluded. The median glomerular filtration rate was 24 (13-36) mL/min/1.73 m2 and the median NT-proBNP was 4,849 (1,310-19,009) pg/mL. The prevalence of LV systolic dysfunction increased from the lower to the upper NT-proBNP quartiles (I, 17%; II, 34%; III, 61%; and IV, 72%; p<0.001 for trend). The NT-proBNP quartile was an independent predictor of LV systolic dysfunction after adjustment for renal function, compared with quartile I: II, odds ratio (OR) 3.99 (95% confidence interval [CI],1.34-11.93); III, OR 11.28 (95% CI, 3.74-33.95); and IV, OR 36.97 (95% CI, 11.47-119.1). Area under the curve and optimum cut points for NT-proBNP to detect LV systolic dysfunction were 0.781 and 2,165 pg/mL in CKD stage 3, 0.812 and 4,740 pg/mL in CKD stage 4, and 0.745 and 15,892 pg/mL in CKD stage 5. The NT-proBNP level was a predictor of LV systolic dysfunction in CKD patients. Optimum cut points should be stratified according to renal function
Whole-exome sequencing in 168 Korean patients with inherited retinal degeneration
Background
To date, no genetic analysis of inherited retinal disease (IRD) using whole-exome sequencing (WES) has been conducted in a large-scale Korean cohort. The aim of this study was to characterise the genetic profile of IRD patients in Korea using WES.
Methods
We performed comprehensive molecular testing in 168 unrelated Korean IRD patients using WES. The potential pathogenicity of candidate variants was assessed using the American College of Medical Genetics and Genomics and the Association for Molecular Pathology variant interpretation guidelines, in silico prediction tools, published literature, and compatibility with known phenotypes or inheritance patterns.
Results
Causative variants were detected in 86/168 (51.2%) IRD patients, including 58/107 (54.2%) with retinitis pigmentosa, 7/15 (46.7%) with cone and cone-rod dystrophy, 2/3 (66.6%) with Usher syndrome, 1/2 (50.0%) with congenital stationary night blindness, 2/2 (100.0%) with Leber congenital amaurosis, 1/1 (100.0%) with Bietti crystalline dystrophy, 1/1 (100.0%) with Joubert syndrome, 9/10 (90.0%) with Stargardt macular dystrophy, 1/10 (10.0%) with vitelliform macular dystrophy, 1/11 (9.1%) with other forms of macular dystrophy, and 3/4 (75.0%) with choroideraemia. USH2A, ABCA4, and EYS were the most common causative genes associated with IRD. For retinitis pigmentosa, variants of USH2A and EYS were the most common causative gene mutations.
Conclusions
This study demonstrated the distribution of causative genetic mutations in Korean IRD patients. The data will serve as a reference for future genetic screening and development of treatment modalities for Korean IRD patients.This study was supported by the Korean Association of Retinal Degenera‑tion, by a Grant Number 2620170060 from the SNUH Research Fund, and by a grant of the Korea Research-Driven Hospital (Grant Number: HI14C1277) through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health and Welfare (MHW), Republic of Korea. The funding
bodies played no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript
Tumor immune profiles noninvasively estimated by FDG PET with deep learning correlate with immunotherapy response in lung adenocarcinoma
Rationale: The clinical application of biomarkers reflecting tumor immune microenvironment is hurdled by the invasiveness of obtaining tissues despite its importance in immunotherapy. We developed a deep learning-based biomarker which noninvasively estimates a tumor immune profile with fluorodeoxyglucose positron emission tomography (FDG-PET) in lung adenocarcinoma (LUAD). Methods: A deep learning model to predict cytolytic activity score (CytAct) using semi-automatically segmented tumors on FDG-PET trained by a publicly available dataset paired with tissue RNA sequencing (n = 93). This model was validated in two independent cohorts of LUAD: SNUH (n = 43) and The Cancer Genome Atlas (TCGA) cohort (n = 16). The model was applied to the immune checkpoint blockade (ICB) cohort, which consists of patients with metastatic LUAD who underwent ICB treatment (n = 29). Results: The predicted CytAct showed a positive correlation with CytAct of RNA sequencing in validation cohorts (Spearman rho = 0.32, p = 0.04 in SNUH cohort; spearman rho = 0.47, p = 0.07 in TCGA cohort). In ICB cohort, the higher predicted CytAct of individual lesion was associated with more decrement in tumor size after ICB treatment (Spearman rho = -0.54, p < 0.001). Higher minimum predicted CytAct in each patient associated with significantly prolonged progression free survival and overall survival (Hazard ratio 0.25, p = 0.001 and 0.18, p = 0.004, respectively). In patients with multiple lesions, ICB responders had significantly lower variance of predicted CytActs (p = 0.005). Conclusion: The deep learning model that predicts CytAct using FDG-PET of LUAD was validated in independent cohorts. Our approach may be used to noninvasively assess an immune profile and predict outcomes of LUAD patients treated with ICB.
Elm tree bark extract inhibits HepG2 hepatic cancer cell growth via pro-apoptotic activity
Control of inflammation is widely accepted as an important strategy for cancer chemoprevention. Anti-inflammatory effects of bark extracts of elm tree (BEE) have been amply reported. Therefore, BEE may be a good candidate cancer chemopreventive agent. Considering the high incidence of hepatic cancer and limited therapeutic approaches for treating this disease, it is important to develop liver cancer-specific chemopreventive agents. To evaluate the chemopreventive potential of BEE, we investigated the growth inhibition effect of BEE on the HepG2 human hepatocellular carcinoma cell line. We performed a cell counting kit-8 assay to determine cell viability, and 4,6-diamino-2-phenylindole staining and flow cytometry to measure apoptotic cell death. Finally, the expression levels of pro- and anti-apoptotic proteins were measured. BEE inhibited the growth of HepG2 cells and induced apoptosis in a dose-dependent manner. Pro-apoptotic activity was promoted via the mitochondrial pathway of apoptosis, as demonstrated by the activation of pro-apoptotic proteins Bax, caspase-9, caspase-3, and poly (ADP-ribose) polymerase as well as the down-regulation of the anti-apoptotic protein Bcl-2. These results suggest that BEE may have potential use in hepatic cancer chemoprevention by suppressing cancer cell growth via pro-apoptotic activity
Adult-onset Still's Disease with Disseminated Intravascular Coagulation and Multiple Organ Dysfunctions Dramatically Treated with Cyclosporine A
Severe systemic manifestations of adult onset Still's disease (AOSD) are often fatal and occasionally related to hemophagocytic syndrome (HS). We describe the case of a 49-yr-old woman with AOSD presenting with non-remitting high fever, confusion, jaundice, hepatosplenomegaly, serositis, azotemia, pancytopenia, coagulopathy with disseminated intravascular coagulation (DIC), hyperferritinemia, acute acalculous cholecystitis and ileocolitis noted in computed tomographic images. The patient had a history of herpes zoster developed prior to the admission, but there is no history of diarrhea or abdominal pain. Although bone marrow examination was not performed due to hemorrhagic diathesis, we suspected AOSD-associated HS on the basis of clinical course without detectable infectious agents in cultures or serologic studies. Intravenous immunoglobulin, pulse methylprednisolone, oral cyclosporine A (CsA) and ceftriaxone brought about transient improvement of fever and confusion, but the disease progressed. After increasing CsA dose, all previously mentioned abnormalities disappeared rapidly. Accordingly, we believe that DIC and multiple organ dysfunctions might have been the complications of HS but not that of sepsis, and that CsA can be used as a first-line therapy in case of life-threatening situations
Universal field-tunable terahertz emission by ultrafast photoinduced demagnetization in Fe, Ni, and Co ferromagnetic films
We report a universal terahertz (THz) emission behavior from simple Ni, Fe, and Co metallic ferromagnetic films, triggered by the femtosecond laser pulse and subsequent photoinduced demagnetization on an ultrafast time scale. THz emission behavior in ferromagnetic films is found to be consistent with initial magnetization states controlled by external fields, where the hysteresis of the maximal THz emission signal is observed to be well-matched with the magnetic hysteresis curve. It is experimentally demonstrated that the ultrafast THz emission by the photoinduced demagnetization is controllable in a simple way by external fields as well as pump fluences. © 2020, The Author(s).1
Impact of Non-vitamin K Antagonist Oral Anticoagulant Withdrawal on Stroke Outcomes
Introduction: Discontinuation of oral anticoagulants such as non-vitamin K antagonist oral anticoagulants (NOACs) may induce a hypercoagulable state, leading to severe stroke and poor outcomes. This study aimed to compare stroke outcomes between NOACs withdrawal and other prior medication statuses in patients with non-valvular atrial fibrillation (NVAF).Methods: Consecutive patients who had pre-existing NVAF and were admitted for an acute ischemic stroke or transient ischemic attack- at five hospitals between January 2013 and December 2016 were included. Prior medication status was categorized into seven groups such as no antithrombotics, antiplatelet-only, warfarin with subtherapeutic intensity, warfarin with therapeutic intensity, NOAC, warfarin withdrawal, and NOAC withdrawal. We compared initial National Institute of Health Stroke Scale (NIHSS) scores between groupsResults: Among 719 patients with NVAF, The median NIHSS score at admission was 5 (IQR 1-13). The NOAC withdrawal group had the highest median NIHSS scores at stroke onset [16, interquartile range, IQR (1–17)], followed by the warfarin withdrawal group [11, IQR (1–14, 18)], the no antithrombotic group [5, IQR (1–13, 18, 19)], and the warfarin with subtherapeutic intensity group [5, IQR (1–10, 18, 19)]. A Multivariable analysis demonstrated that NOAC withdrawal was independently associated with higher NIHSS scores at stroke onset (B 4.645, 95% confidence interval 0.384–8.906, P = 0.033). The median interval from drug withdrawal to ischemic stroke or TIA was 7 days (IQR 4-15) in the NOAC group.Conclusions: Stroke that occurred after stopping oral anticoagulants, especially NOAC, and was more severe at presentation and associated with poorer outcomes
Highly Pathogenic Avian Influenza Virus (H5N1) in Domestic Poultry and Relationship with Migratory Birds, South Korea
During the 2006–2007 winter season in South Korea, several outbreaks of highly pathogenic avian influenza virus (H5N1) were confirmed among domestic poultry and in migratory bird habitats. Phylogenetic analysis showed that all isolates were closely related and that all belong to the A/bar-headed goose/Qinghai/5/2005–like lineage rather than the A/chicken/Korea/ES/2003–like lineage
Utility of Postmortem Autopsy via Whole-Body Imaging: Initial Observations Comparing MDCT and 3.0T MRI Findings with Autopsy Findings
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