Publications by authors named "Ihara R"

Article Synopsis
  • α-synuclein seed amplification assays (α-syn SAA) show promise but may have reduced sensitivity due to variations among patients with Lewy body disease (LBD).
  • In a study of 34 Parkinson's disease (PD) patients and 7 with dementia with Lewy bodies (DLB), 85.2% of those with abnormal cardiac MIBG scans tested positive for α-syn SAA, while only 14.3% of those with normal scans did.
  • MIBG cardiac scintigraphy was identified as a significant factor influencing α-syn SAA positivity, indicating that while α-syn SAA can be sensitive for LBD in specific cases, its effectiveness may be diminished in patients with normal M
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  • The study investigates public and clinical specialists' perceptions regarding preparedness for administering disease-modifying treatments (DMT) for Alzheimer’s disease, focusing on the newly approved drug lecanemab.
  • Conducted through online and mail surveys, it gathered responses from over 2,000 participants, highlighting significant differences in views about treatment eligibility and efficacy between general public respondents and clinical specialists.
  • While both groups were generally supportive of prioritizing patients for treatment, the public expressed more restrictive views on who qualifies for DMT and appeared more optimistic about its effectiveness compared to specialists.
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Purpose: The aims of this study are to explore the apparent diffusion coefficient (ADC)-dependent thresholds for time to reperfusion in reversible lesions following mechanical thrombectomy for acute ischemic stroke, and to investigate the associated risks of hemorrhagic transformation.

Methods: We conducted a retrospective case-control study, enrolling patients with large-vessel occlusion who underwent mechanical thrombectomy in Otaru General Hospital from 2016 to 2021. Reversible lesions were identified using volumetric ADC data, and the mean time from image to reperfusion (TIR) in each ADC range was compared between groups with and without reversible lesions, as well as those with and without parenchymal hematoma.

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  • EUS-guided biliary drainage (EUS-BD) has shown good results in high-volume centers, but this study investigates its safety and effectiveness in newer centers that recently adopted the procedure.
  • The research involved 22 centers from 2017 to 2022, assessing 255 patients and looking at the success and complications of EUS-BD performed by 84 endoscopists.
  • The study found a high technical success rate of 91.4% but identified specific risks for failure and complications, including smaller puncture target diameters and moderate ascites, highlighting that the experience level of endoscopists did not significantly affect outcomes.
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  • Anti-amyloid drugs like lecanemab used for early Alzheimer's disease can cause adverse events (AEs), including specific brain imaging abnormalities and infusion reactions.
  • A meta-analysis was conducted to assess the predictive value of these adverse events, revealing that ARIA-E has a high positive predictive value (PPV) of 0.915, while ARIA hemorrhage has a low PPV of 0.630.
  • The findings indicate that the impact of AEs, especially ARIA-E, can influence the results of clinical trials and emphasize the need to reduce potential biases stemming from these events.
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  • In Parkinson's disease patients, levels of cerebrospinal fluid metabolites homovanillic acid (HVA) and 5-hydroxyindole acetic acid (5-HIAA), which are linked to dopamine and serotonin, are found to be decreased.
  • A study involving 57 drug-naïve PD patients indicated significant differences in 5-HIAA levels between those with positive vs negative cardiac MIBG imaging, suggesting a direct association.
  • Additionally, a correlation was found between HVA levels and striatal dopamine transporter binding, confirming that both HVA and 5-HIAA have important roles in PD pathology and imaging outcomes.
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  • - The approval of lecanemab for early Alzheimer's treatment in 2023 revealed regional differences in the availability and frequency of MRI scans needed to monitor side effects of the therapy, potentially impacting consistent care nationwide.
  • - The study analyzed MRI scan data across Japan from 2015 to 2021, using a model to assess variations in MRI usage and categorizing regions based on frequency and types of MRI scanners.
  • - Findings indicated that 1.5T MRIs were the most common, with a slight increase in 3.0T MRI usage, particularly in western Japan, and emphasized the need for better regional healthcare readiness for managing Alzheimer's treatments.
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-ε4 allele[s] is a risk factor for Alzheimer's disease (AD) and Amyloid-Related Imaging Abnormalities (ARIA) in anti-amyloid beta therapy, and is also associated with cerebrovascular risk factors such as hyperlipidemia or atherosclerosis. During AD clinical trials, -ε4 carriers may experience neuropsychiatric adverse events (AEs) related to these risks, complicating the differentiation of ARIA from cerebrovascular events based on symptoms. This study aimed to examine the hypothetical impact of considering the -ε4 allele's risk for non-ARIA AEs during AD clinical trials.

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18 F-labeled THK5351 PET can visualize ongoing astrogliosis by estimating monoamine oxidase B levels and can be used as an adjunct for diagnosing neurodegenerative disorders. Little has been reported on multiple system atrophy (MSA) in the differential diagnosis of parkinsonian syndromes. Here, we present 18 F-THK5351 images in typical cases of MSA-P (parkinsonian type) and MSA-C (cerebellar type), showing intense 18 F-THK5351 uptake in the lateral-posterior part of the putamen (MSA-P) and in the pons and middle cerebellar peduncles (MSA-C).

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Cocoa extract (CE) offers several health benefits, such as antiobesity and improved glucose intolerance. However, the mechanisms remain unclear. Adipose tissue includes white adipose tissue (WAT) and brown adipose tissue.

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Background: Maximizing the efficiency to screen amyloid-positive individuals in asymptomatic and non-demented aged population using blood-based biomarkers is essential for future success of clinical trials in the early stage of Alzheimer's disease (AD). In this study, we elucidate the utility of combination of plasma amyloid-β (Aβ)-related biomarkers and tau phosphorylated at threonine 217 (p-tau217) to predict abnormal Aβ-positron emission tomography (PET) in the preclinical and prodromal AD.

Methods: We designed the cross-sectional study including two ethnically distinct cohorts, the Japanese trial-ready cohort for preclinica and prodromal AD (J-TRC) and the Swedish BioFINDER study.

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Background: Primary outcome measure in the clinical trials of disease modifying therapy (DMT) drugs for Alzheimer's disease (AD) has often been evaluated by Clinical Dementia Rating sum of boxes (CDRSB). However, CDR testing requires specialized training and 30-50 minutes to complete, not being suitable for daily clinical practice.

Objective: Herein, we proposed a machine-learning method to estimate CDRSB changes using simpler cognitive/functional batteries (Mini-Mental State Examination [MMSE] and Functional Activities Questionnaire [FAQ]), to replace CDR testing.

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Background: We have been conducting a Japanese trial-ready cohort web study since 2019 as a web-based online registry to enroll individuals with preclinical Alzheimer's disease to facilitate trials on Alzheimer's disease prevention. The usability of a website might be an important factor in determining user participation and retention.

Objectives: We conducted a user questionnaire survey to analyze the usability of the Japanese trial-ready cohort website and user characteristics for future website improvement.

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Article Synopsis
  • Istradefylline (IST) is investigated as an adjunctive treatment for Parkinson's disease (PD) to see if it can reduce the need for higher doses of levodopa, which is commonly linked to motor complications.
  • In a study with 114 PD patients experiencing wearing-off symptoms, those receiving IST required significantly less additional levodopa over 37 weeks compared to those who did not receive IST.
  • Patients treated with IST also showed improvements in motor functions measured by rating scales and wearable devices, suggesting that IST may enhance symptom management without increasing levodopa dosage significantly.
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The APOE-ε4 allele(s) is a strong risk factor for Alzheimer's disease (AD). A significant point of access for this allele testing is through services provided by medical facilities in Japan, which advertise out-of-insurance APOE testing on their websites. There is a concern that website advertisements for APOE testing may influence the ability for individuals to adequately self-determine whether to undergo APOE testing.

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Background: Magnetic resonance cholangiopancreatography (MRCP) may exhibit ghosting and blurring artifacts due to irregular breathing cycles, which can be overcome by shortening the shot duration. T2 preparation pulse enables heavy T2 contrast even with a shorter TE by use of the shortened shot duration; therefore, a technique using T2 preparation pulse combined with 3D turbo spin-echo MRCP (TPT-MRCP) was constructed.

Purpose: To evaluate the clinical usefulness of TPT-MRCP in both navigation and breath-hold sequences compared to the conventional method.

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Background: 18F-THK5351 PET is used to image ongoing astrogliosis by estimating monoamine oxidase B levels. 18F-THK5351 preferentially accumulates around the substantia nigra (SN) and periaqueductal gray (PG) in the midbrain under healthy conditions and exhibits a "trimodal pattern." In progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS), the midbrain 18F-THK5351 uptake can be increased by astrogliosis, collapsing the "trimodal pattern.

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Article Synopsis
  • Corticobasal syndrome (CBS) involves asymmetric symptoms due to issues in the cerebral cortex and basal ganglia, making early detection of imaging abnormalities difficult.
  • Previous studies found asymmetric F-THK5351 PET abnormalities in CBS patients, but their effectiveness in larger early-stage groups needed further exploration.
  • In a study of 15 CBS patients, 100% exhibited asymmetric tracer uptake on imaging, with F-THK5351 PET showing high sensitivity for identifying these abnormalities compared to other imaging techniques.
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Predicting outcomes after mechanical thrombectomy (MT) remains challenging for patients with acute ischemic stroke (AIS). This study aimed to explore the usefulness of machine learning (ML) methods using detailed apparent diffusion coefficient (ADC) analysis to predict patient outcomes and simulate the time limit for MT in AIS. A total of 75 consecutive patients with AIS with complete reperfusion in MT were included; 20% were separated to test data.

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  • The study examines the relationship between cerebrospinal fluid (CSF) homovanillic acid (HVA) and striatal dopamine transporter (DAT) binding in patients with various neurological conditions, focusing on Parkinson's disease (PD) and progressive supranuclear palsy (PSP).
  • Results indicate a significant correlation between CSF HVA levels and DAT binding, especially in patients with PD (r = 0.34) and PSP (r = 0.77), suggesting that lower DAT binding may be linked to dopamine levels in the brain.
  • Findings reveal that patients with PSP had the lowest DAT binding compared to those with PD, indicating that striatal DAT reduction is more pronounced in PSP, potentially reflecting
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Aims: TMS-007, an SMTP family member, modulates plasminogen conformation and enhances plasminogen-fibrin binding, leading to promotion of endogenous fibrinolysis. Its anti-inflammatory action, mediated by soluble epoxide hydrolase inhibition, may contribute to its efficacy. Evidence suggests that TMS-007 can effectively treat experimental thrombotic and embolic strokes with a wide time window, while reducing haemorrhagic transformation.

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  • CSF p-tau181 is a key biomarker for Alzheimer's disease (AD) and the study aimed to see if it changes in patients with Neuronal Intranuclear Inclusion Disease (NIID), a neurodegenerative disorder.
  • The research compared CSF biomarker levels, including p-tau181, across 12 NIID patients, 120 confirmed AD patients, and various other neurocognitive disorder patients.
  • Results showed significantly elevated CSF p-tau181 levels in NIID patients compared to others, indicating that NIID might share some biochemical features with AD despite the differences in other biomarkers like Aβ42.
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Predator-prey interactions based on laterality have recently been observed between fishes and their prey populations. Maintenance of antisymmetric dimorphism by frequency-dependent selection has been reported in fish, but has not been observed in invertebrates. Over 10 years, we investigated long-term changes in the "ratio of laterality" (frequency of righty morphs in a population) in the cuttlefish and its potential prey prawns and in the Visayan Sea, the Philippines.

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Background: The AT(N) classification was proposed for categorising individuals according to biomarkers. However, AT(N) profiles may vary depending on the markers chosen and the target population.

Methods: We stratified 177 individuals who participated in the Japanese Alzheimer's Disease Neuroimaging Initiative by AT(N) classification according to cerebrospinal fluid (CSF) biomarkers.

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[Background and Purpose] Clot location and range predict clinical outcomes for acute ischemic stroke (AIS). We developed a new technique for visualizing occlusion clots, namely, the DEpicting blood clot and MRA using Phase contrast angiography with Image Calculation for Thrombectomy (DEPICT) method. The purpose of this study was to assess the clinical usefulness of DEPICT.

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