Publications by authors named "Bang O"

Background: The effects of blood pressure (BP) lowering in patients treated with intravenous tissue plasminogen activator (IV tPA) before endovascular thrombectomy (EVT) are unclear.

Aims: This study aims to investigate whether intensive and conventional BP management affect outcomes differently, depending on IV tPA administration before EVT.

Methods: In this subgroup analysis of the Outcome in Patients Treated with Intra-Arterial Thrombectomy-Optimal Blood Pressure Control (OPTIMAL-BP; ClinicalTrials.

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Combining near-infrared (NIR) and mid-infrared (MIR) spectroscopy to cover both the fundamental and overtone combination molecular vibrational resonances allows more robust analytical methods to be used, such as two-dimensional correlation spectroscopy. However, due to the strong differences in molar absorption coefficients and transparency of the optical material, it is inherently difficult to perform NIR and MIR spectroscopy on aqueous samples using a single instrument. Combining spectra from different instruments and sample presentations can result in unwanted spectral variations, which can influence the prediction models and mitigate the advantages of the combination approaches.

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Background: Intensive blood pressure (BP) management within 24 h after successful reperfusion following endovascular thrombectomy (EVT) is associated with worse functional outcomes than conventional BP management in Asian randomized controlled trials. Given the high prevalence of intracranial atherosclerotic stenosis (ICAS) in Asia, ICAS may influence these outcomes.

Aims: We aimed to assess whether ICAS affects the outcomes of intensive BP management after successful EVT.

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Aging manifests as many phenotypes, among which age-related changes in brain vessels are important, but underexplored. Thus, in the present study, we constructed a model to predict age using cerebrovascular morphological features, further assessing their clinical relevance using a novel pipeline. Age prediction models were first developed using data from a normal cohort (n = 1181), after which their relevance was tested in two stroke cohorts (n = 564 and n = 455).

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Ischemic stroke is a major cause of mortality worldwide. Proper etiological subtyping of ischemic stroke is crucial for tailoring treatment strategies. This study explored the utility of circulating microRNAs encapsulated in extracellular vesicles (EV-miRNAs) to distinguish the following ischemic stroke subtypes: large artery atherosclerosis (LAA), cardioembolic stroke (CES), and small artery occlusion (SAO).

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Background: Sex differences in stroke outcomes are notable, with women experiencing higher incidence rates, greater disability-adjusted life years, and poorer recovery compared to men, even after adjusting for age and comorbidities. Despite the disproportionate burden in women, studies have reported that women are less likely to receive appropriate stroke treatment than men.

Aim: This study investigated temporal trends of sex differences in acute reperfusion therapy and early outcomes in patients with acute ischemic stroke over 10 years in South Korea.

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Article Synopsis
  • Accurate classification of ischemic stroke subtypes is crucial for effective prevention strategies, and a deep learning algorithm was developed using diffusion-weighted imaging (DWI) and atrial fibrillation (AF) data for this purpose.
  • The study involved training models on a dataset of 2,988 stroke patients using two algorithms: one based solely on DWI and another incorporating AF as a factor.
  • Results showed that the DWI+AF algorithm achieved higher agreement rates with expert opinions compared to the DWI-only method, indicating its effectiveness in accurately classifying stroke subtypes.
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Article Synopsis
  • The study explores the connection between infarct volume in acute ischemic stroke patients and their chances of achieving good clinical outcomes based on the modified Rankin Scale (mRS).
  • Using data from the ESCAPE-NA1 trial, researchers analyzed how changes in infarct volume influence the probabilities of recovery in 1,099 patients over 24 hours post-treatment.
  • Findings indicate a nearly linear relationship between infarct volume and good outcomes up to 250 mL, suggesting that significant reductions in infarct size are necessary to improve chances of recovery, especially as patients with volumes over 250 mL have very low probabilities of good outcomes.
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The effect of arterial tortuosity on intracranial atherosclerosis (ICAS) is not well understood. This study aimed to evaluate the effect of global intracranial arterial tortuosity on intracranial atherosclerotic burden in patients with ischemic stroke. We included patients with acute ischemic stroke who underwent magnetic resonance angiography (MRA) and classified them into three groups according to the ICAS burden.

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Article Synopsis
  • The study investigated the impact of endovascular therapy (EVT) on cognitive outcomes following a large vessel occlusion stroke, using data from the ESCAPE trial.
  • Cognitive assessments were performed 90 days post-stroke and included various tests to evaluate memory and cognitive function, with results indicating that EVT significantly improved cognitive outcomes across all tests.
  • Findings showed that EVT was associated with better cognitive performance (higher odds ratios for favorable outcomes), and both final infarct volume and cognitive function had notable correlations, suggesting that both factors influence recovery.
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Importance: The associations between blood pressure (BP) decreases induced by medication and functional outcomes in patients with successful endovascular thrombectomy remain uncertain.

Objective: To evaluate whether BP reductions induced by intravenous BP medications are associated with poor functional outcomes at 3 months.

Design, Setting, And Participants: This cohort study was a post hoc analysis of the Outcome in Patients Treated With Intra-Arterial Thrombectomy-Optimal Blood Pressure Control trial, a comparison of intensive and conventional BP management during the 24 hours after successful recanalization from June 18, 2020, to November 28, 2022.

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Background: This study aimed compare efficacy of edoxaban and enoxaparin upon biomarkers of hypercoagulability in patients with cancer-related embolic stroke of undetermined source (ESUS).

Methods: In this open-label, randomized, pilot trial, patients with cancer-related ESUS within 30 days of diagnosis were randomly assigned (1:1) to receive edoxaban (60 mg once daily) or enoxaparin (1 mg/kg twice daily) for 90 days. The primary endpoint was interval change of serum D-dimer level between days 0 and 7.

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Background: The effectiveness of endovascular treatment for in-hospital stroke remains debatable. We aimed to compare the outcomes between patients with in-hospital stroke and community-onset stroke who received endovascular treatment.

Methods: This prospective registry-based cohort study included consecutive patients who underwent endovascular treatment from January 2013 to December 2022 and were registered in the Selection Criteria in Endovascular Thrombectomy and Thrombolytic Therapy study and Yonsei Stroke Cohort.

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Stem-cell-derived extracellular vesicles (EVs) are emerging as an alternative approach to stem cell therapy. Successful lyophilization of EVs could enable convenient storage and distribution of EV medicinal products at room temperature for long periods, thus considerably increasing the accessibility of EV therapeutics to patients. In this study, we aimed to identify an appropriate lyoprotectant composition for the lyophilization and reconstitution of stem-cell-derived EVs.

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Background: Constipation symptoms are highly prevalent in acute ischemic stroke, but the clinical and neuroimaging predictors are unknown. This study aimed to identify lesions and clinical features associated with acute constipation.

Methods: Data from patients with acute ischemic stroke registered in a hospital-based stroke registry between January 2018 and December 2019 were analyzed.

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In this paper, we present numerical and experimental results on Localized Surface Plasmon Resonance (LSPR) refractive index (RI) sensitivity, Figure of Merit (FoM), and penetration depth () dependence on spherical gold nanoparticles (AuNPs) size, and the effects of AuNP dimer interparticle distance () studied numerically. These parameters were calculated and observed for = 20, 40, 60, 80, and 100 nm diameter spherical AuNPs. Our investigation shows = 60 nm AuNPs give the best FoM.

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Importance: Optimal blood pressure (BP) control after successful reperfusion with endovascular thrombectomy (EVT) for patients with acute ischemic stroke is unclear.

Objective: To determine whether intensive BP management during the first 24 hours after successful reperfusion leads to better clinical outcomes than conventional BP management in patients who underwent EVT.

Design, Setting, And Participants: Multicenter, randomized, open-label trial with a blinded end-point evaluation, conducted across 19 stroke centers in South Korea from June 2020 to November 2022 (final follow-up, March 8, 2023).

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Adult moyamoya disease and syndrome are rare disorders with significant morbidity and mortality. A writing group of experts was selected to conduct a literature search, summarize the current knowledge on the topic, and provide a road map for future investigation. The document presents an update in the definitions of moyamoya disease and syndrome, modern methods for diagnosis, and updated information on pathophysiology, epidemiology, and both medical and surgical treatment.

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Introduction: The D-dimer to fibrinogen ratio (DFR) is a good indicator of clot-producing activity in thrombotic disease, but its clinical usefulness in stroke patients with nonvalvular atrial fibrillation (NVAF) has not been studied. We evaluated the association between the DFR and early neurological deterioration (END) in acute ischemic stroke (AIS) patients with NVAF.

Methods: We included consecutive AIS patients with NVAF between 2013 and 2015 from the registry of a real-world prospective cohort from 11 large centers in South Korea.

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Background Although it is well known that the disordered brain provokes cardiac autonomic dysfunction, the detailed location of brain lesions related to cardiac function warrants further investigation. We aimed to elucidate the brain lesions topographically associated with left ventricular (LV) systolic function measured by myocardial strain in patients with acute ischemic stroke without preexisting primary cardiac dysfunction by using support vector regression lesion-symptom mapping. Methods and Results Subjects were those with LV ejection fraction of 50% or more among patients with acute ischemic stroke registered in the Samsung Medical Center stroke registry between 2016 and 2017.

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Background And Purpose: The congestive heart failure, hypertension, age, diabetes, previous stroke/transient ischemic attack (CHADS-VASc) and hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol (HAS-BLED) scores have been validated in estimating the risks of ischemic stroke and major bleeding, respectively, in patients with atrial fibrillation (AF). This study investigated stroke-specific predictors of major bleeding in patients with stroke and AF who were taking oral anticoagulants (OACs).

Methods: Subjects were selected from patients enrolled in the Korean ATrial fibrillaTion EvaluatioN regisTry in Ischemic strOke patieNts (K-ATTENTION) nationwide multicenter registry between 2013 and 2015.

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A major clinical hurdle to translate MSC-derived extracellular vesicles (EVs) is the lack of a method to scale-up the production of EVs with customized therapeutic properties. In this study, we tested whether EV production by a scalable 3D-bioprocessing method is feasible and improves neuroplasticity in animal models of stroke using MRI study. MSCs were cultured in a 3D-spheroid using a micro-patterned well.

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We numerically investigate high-power, modulational instability-based supercontinuum sources. Such sources have spectra that reach the infrared material absorption edge and as a result the spectrum has a strong narrow blue peak (dispersive wave group velocity matched to solitons at the infrared loss edge) followed by a significant dip in the neighboring longer-wavelength region. In a wide range of applications one prefers a broader and more flat blue part within a certain minimum and maximum power spectral density.

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Background And Purpose: This study aimed to evaluate whether extracellular-vesicle-incorporated microRNAs (miRNAs) are potential biomarkers for cancer-related stroke.

Methods: This cohort study compared patients with active cancer who had embolic stroke of unknown sources (cancer-stroke group) with patients with only cancer, patients with only stroke, and healthy individuals (control groups). The expression profiles of miRNAs encapsulated in plasma exosomes and microvesicles were evaluated using microarray and validated using quantitative real-time polymerase chain reaction.

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Background And Aims: Pleiotropic effects of statins result in the stabilization of symptomatic intracranial arterial plaque. However, little is known about the effect of statins in non-symptomatic cerebral arteries. We hypothesized that intensive statin therapy could produce a change in the non-symptomatic cerebral arteries.

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