Alzheimers Dement (Amst)
August 2025
Introduction: Cognitive decline in Alzheimer's disease (AD) is closely linked to tau pathology, which leads to loss of synaptic connections and ultimately neurons. While tau positron emission tomography (PET) carries radiation risks, is costly, and often unavailable in clinical settings, brain entropy mapping via resting-state functional magnetic resonance imaging (fMRI) has emerged as a marker of impaired brain function related to tauopathy.
Methods: Using data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) and Estudio de la Enfermedad de Alzheimer en Jalisciences (EEAJ), we investigate the classification performance of fMRI entropy with tau PET in distinguishing cognitively normal (CN) from cognitively impaired (mild cognitive impairment/AD) individuals.
Study Objectives: Despite persistent nursing shortages, newly hired nurses inevitably engage in shift work (SW), which harms their sleep and mental health, accelerating their early-career turnover. This study examined whether pre-SW chronotype is associated with post-SW sleep/mental health outcomes and whether resilience mediates these relationships.
Methods: A prospective cohort of 595 newly hired nurses, of whom 331 were included in the final analysis, was recruited from two national tertiary hospitals.
Recent machine-learning techniques may be useful to identify subtypes with distinct spatial patterns of biomarker abnormality in the various neurodegenerative diseases. Using the Subtype and Stage Inference (SuStaIn) technique, we categorized data-driven subtypes of PD by examining the deep gray matter volume and dopamine availability and compared cardiac denervation, cognition, and motor symptoms between these subtypes. The SuStaIn algorithm revealed two distinctive subtypes, which were well replicated in an external dataset.
View Article and Find Full Text PDFBackground: The Mini-Mental State Examination (MMSE) is the most widely used cognitive screening test worldwide; however, it often overdiagnoses older adults with low education levels. In contrast, the Cognitive Impairment Screening Test (CIST), developed by South Korea's Ministry of Health and Welfare, may address this shortcoming. In this study, we compare the CIST and the Korean version of the MMSE (K-MMSE) in older adults with no formal education.
View Article and Find Full Text PDFBackground: Several subtyping methods have been proposed to characterize Parkinson's disease (PD) progression, yet the trajectory of subcortical and cortical neurodegeneration and its clinical implications remain unclear.
Objectives: We aimed to conduct a strictly image-based, data-driven classification of PD progression through Subtype and Stage Inference (SuStaIn) algorithm.
Methods: Brain volumetric data from 565 patients with PD and 150 propensity-matched healthy controls were analyzed.
Background: Tau protein accumulation is closely linked to synaptic and neuronal loss in Alzheimer's disease (AD), resulting in progressive cognitive decline. Although tau-PET imaging is a direct biomarker of tau pathology, it is costly, carries radiation risks, and is not widely accessible. Resting-state functional MRI (rs-fMRI) complexity-an entropy-based measure of BOLD signal variation-has been proposed as a non-invasive surrogate biomarker of early neuronal dysfunction associated with tau pathology.
View Article and Find Full Text PDFJ Am Heart Assoc
December 2024
Background: Impaired cardiac function is associated with cognitive impairment and brain imaging features of aging. Cardiac arrhythmias, including atrial fibrillation, are implicated in clinical and subclinical brain injuries. Even in the absence of a clinical diagnosis, subclinical or prodromal substrates of arrhythmias, including an abnormally long or short P-wave duration (PWD), a measure associated with atrial abnormalities, have been associated with stroke and cognitive decline.
View Article and Find Full Text PDFThe frequency of the apolipoprotein E ɛ4 allele and vascular risk factors differs among ethnic groups. We aimed to assess the combined effects of apolipoprotein E ɛ4 and vascular risk factors on brain age in Korean and UK cognitively unimpaired populations. We also aimed to determine the differences in the combined effects between the two populations.
View Article and Find Full Text PDFBackground And Objectives: Cognitive impairment is a frequent nonmotor symptom in patients with Parkinson disease (PD), and early cognitive decline is often attributed to dopaminergic system dysfunction. We aimed to explore spatiotemporal progression patterns of striatal dopamine availability and regional brain volume based on cognitive status among patients with PD.
Methods: This retrospective, cross-sectional study included patients with newly diagnosed PD who were not taking medication for this condition who visited a university-affiliated hospital in Seoul between January 2018 and December 2020.
Impaired cardiac function is associated with cognitive impairment and brain imaging features of aging. Cardiac arrhythmias, including atrial fibrillation, are implicated in clinical and subclinical brain injuries. Even in the absence of a clinical diagnosis, subclinical or prodromal substrates of arrhythmias, including an abnormally long or short P-wave duration (PWD), a measure associated with atrial abnormalities, have been associated with stroke and cognitive decline.
View Article and Find Full Text PDFBackground And Objectives: Functional outcomes after stroke are strongly related to focal injury measures. However, the role of global brain health is less clear. In this study, we examined the impact of brain age, a measure of neurobiological aging derived from whole-brain structural neuroimaging, on poststroke outcomes, with a focus on sensorimotor performance.
View Article and Find Full Text PDFAlzheimers Res Ther
March 2023
Background: A growing body of evidence shows differences in the prevalence of cardiometabolic syndrome (CMS) and dementia based on gender and ethnicity. However, there is a paucity of information about ethnic- and gender-specific CMS effects on brain age. We investigated the different effects of CMS on brain age by gender in Korean and British cognitively unimpaired (CU) populations.
View Article and Find Full Text PDFSleep architecture and microstructures alter with aging and sleep disorder-led accelerated aging. We proposed a sleep EEG based brain age prediction model using convolutional neural networks. We then associated the estimated brain age index with brain structural aging features, sleep disorders and various sleep parameters.
View Article and Find Full Text PDFStroke
March 2022
Background And Purpose: Cerebral small vessel disease is characterized by progressive cerebral white matter changes (WMCs). This study aimed to compare the effects of cilostazol and aspirin on changes in WMC volume in patients with cerebral small vessel disease.
Methods: In a multicenter, double-blind, randomized controlled trial, participants with moderate or severe WMCs and at least one lacunar infarction detected on brain magnetic resonance imaging were randomly assigned to the cilostazol and aspirin groups in a 1:1 ratio.
The accurate prediction of fetal brain age using magnetic resonance imaging (MRI) may contribute to the identification of brain abnormalities and the risk of adverse developmental outcomes. This study aimed to propose a method for predicting fetal brain age using MRIs from 220 healthy fetuses between 15.9 and 38.
View Article and Find Full Text PDFWhite matter hyperintensities (WMHs) are abnormal signals within the white matter region on the human brain MRI and have been associated with aging processes, cognitive decline, and dementia. In the current study, we proposed a U-Net with multi-scale highlighting foregrounds (HF) for WMHs segmentation. Our method, U-Net with HF, is designed to improve the detection of the WMH voxels with partial volume effects.
View Article and Find Full Text PDFFront Neurosci
December 2020
Fetal magnetic resonance imaging (MRI) has the potential to advance our understanding of human brain development by providing quantitative information of cortical plate (CP) development . However, for a reliable quantitative analysis of cortical volume and sulcal folding, accurate and automated segmentation of the CP is crucial. In this study, we propose a fully convolutional neural network for the automatic segmentation of the CP.
View Article and Find Full Text PDFHere, we constructed an attenuated live marker classical swine fever (CSF) vaccine (Flc-LOM-BE) to eradicate CSF. This was done by taking infectious clone Flc-LOM, which is based on an attenuated live CSF vaccine virus (LOM strain), and removing the full-length classical swine fever virus (CSFV) E sequences and the 3' end (52 base pairs) of the CSFV capsid. These regions were substituted with the full-length bovine viral diarrhoea virus (BVDV) E gene sequence and the 3' end (52 base pairs) of the BVDV capsid gene.
View Article and Find Full Text PDFJ Clin Med
March 2019
We aimed to present the study design of an independent validation cohort from the Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's disease (AD) (KBASE-V) and to investigate the baseline characteristics of the participants according to the AD clinical spectrum. We recruited 71 cognitively normal (CN) participants, 96 with subjective cognitive decline (SCD), 72 with mild cognitive impairment (MCI), and 56 with AD dementia (ADD). The participants are followed for three years.
View Article and Find Full Text PDFIn this paper, we introduce a novel automatic method for Corpus Callosum (CC) in midsagittal plane segmentation. The robust segmentation of CC in midsagittal plane is key role for quantitative study of structural features of CC associated with various neurological disorder such as epilepsy, autism, Alzheimer's disease, and so on. Our approach is based on Bayesian inference using sparse representation and multi-atlas voting which both methods are used in various medical imaging, and show outstanding performance.
View Article and Find Full Text PDFJ Alzheimers Dis
August 2019
Background: Alzheimer's disease (AD) and mild cognitive impairment (MCI) are age-related neurodegenerative diseases characterized by progressive loss of memory and irreversible cognitive functions. The hippocampus, a brain area critical for learning and memory processes, is especially susceptible to damage at early stages of AD.
Objective: We aimed to develop prediction model using a multi-modality sparse representation approach.
To investigate the contributions of carboxyl-terminal nucleic acid binding domain of HBV core (C) protein for hepatitis B virus (HBV) replication, chimeric HBV C proteins were generated by substituting varying lengths of the carboxyl-terminus of duck hepatitis B virus (DHBV) C protein for the corresponding regions of HBV C protein. All chimeric C proteins formed core particles. A chimeric C protein with 221-262 amino acids of DHBV C protein, in place of 146-185 amino acids of the HBV C protein, supported HBV pregenomic RNA (pgRNA) encapsidation and DNA synthesis: 40% amino acid sequence identity or 45% homology in the nucleic-acid binding domain of HBV C protein was sufficient for pgRNA encapsidation and DNA synthesis, although we predominantly detected spliced DNA.
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