Publications by authors named "Masanori Kurihara"

Digital bioanalysis enables highly sensitive detection of biomolecules at the single-molecule level, making it a widely used technique in biomedical research. However, conventional approaches typically rely on fluorescence detection of single-enzyme reactions, which limits molecular selectivity and the ability to analyze multiple targets simultaneously. To address these limitations, we developed a digital bioanalysis platform based on surface-enhanced Raman scattering spectroscopy and microchamber arrays decorated with silver nanoparticles.

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Amyloid-beta (Aβ) plays a pivotal role in cognitive decline in Parkinson's disease (PD). The prevalence of amyloid positivity, evaluated using the cerebrospinal fluid (CSF) of patients with PD without dementia in their sixties, is lower than that in individuals with normal cognition without PD diagnosis in the same age range. However, it is unclear whether this is also the case in patients with PD without dementia in their eighties.

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Diagnosing frontal variant Alzheimer's disease (fvAD) is difficult and could be even more difficult when amyloid-beta (Aβ) PET retention is low. A 63-year-old woman presenting with a 3-year history of apathy and memory impairment showed executive dysfunction, memory impairment, and severe bilateral frontotemporal atrophy on MRI. Aβ PET showed only equivocal findings in the right frontal lobe and was negative.

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  • A case study focused on a 71-year-old woman with right temporal variant frontotemporal dementia (rtvFTD) revealed significant heading disorientation, showing that neurodegenerative diseases might impact spatial navigation differently than cerebrovascular diseases.
  • Despite preserved general cognition, the patient struggled with familiar environments, unable to draw routes or maps, although she recognized landmarks; neuropsychological tests indicated specific heading disorientation related to her condition.
  • Imaging studies (MRI and PET) showed notable abnormalities in the right hemisphere, especially in the retrosplenial region, which is linked to heading disorientation, and the patient’s symptoms worsened over time, which is distinct from prior observations with cerebrovascular cases.
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As society ages, the number of people with dementia increases worldwide, and the prevention of dementia has become increasingly important. Lifestyle diseases are associated with the development of dementia, and preventing or controlling lifestyle diseases in middle-aged individuals is particularly important. Hypertension, diabetes, and dyslipidemia are associated with dementia.

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  • 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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  • A 72-year-old man experienced a 6-month decline in voluntary speech marked by sparse speech and decreased word fluency, while other language abilities remained intact, indicating dynamic aphasia.
  • Brain MRI showed left-sided white matter volume reduction in the frontal lobe, specifically affecting areas linked to speech production, and the patient's condition worsened over two years leading to complete mutism and death from aspiration pneumonia.
  • The neuropathological diagnosis was corticobasal degeneration (CBD), suggesting that early signs of CBD may manifest as dynamic aphasia, potentially due to early involvement of certain brain pathways.
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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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An 81-year-old woman presented with statin-induced anti-HMGCR immune-mediated necrotizing myopathy. Treatment was successful without complications with a reduced oral steroid dosage from the current consensus for all ages and backgrounds. This case suggests the importance of early diagnosis and the possibility of steroid dosage adjustment considering the patient's age, disease severity, and comorbidities.

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Background: Although Lumipulse assays and conventional ELISA are strongly correlated, the precise relationship between their measured values remains undetermined.

Objective: To determine the relationship between Lumipulse and ELISA measurement values.

Methods: Patients who underwent cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarker measurements and consented to biobanking between December 2021 and June 2023 were included.

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Recent studies suggest that increased cerebrospinal fluid (CSF) phospho-tau is associated with brain amyloid pathology rather than the tau pathology. However, confirmation using gold standard neuropathological assessments remains limited. This study aimed to determine background pathologies associated with aberrant CSF p-tau181 and amyloid-beta 1-42 (Aβ42) in Alzheimer's disease (AD) and other neurodegenerative diseases.

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We present 3 patients as pitfalls of amyloid-beta (Aβ) PET, who underwent 11 C-PiB (Aβ), 18 F-MK-6240 (Alzheimer disease [AD]-tau), and 18 F-THK5351 (astrogliosis) PET examinations. Despite negligible or tiny Aβ pathology, patients 1 and 2 were diagnosed with AD as the cause of symptoms. Despite widespread Aβ pathology, patient 3 was not diagnosed with AD as the cause of symptoms.

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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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  • 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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  • 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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Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease characterized by eosinophilic hyaline intranuclear inclusions in the neurons, glial cells, and other somatic cells. Although CGG repeat expansions in NOTCH2NLC have been identified in most East Asian patients with NIID, the pathophysiology of NIID remains unclear. Ubiquitin- and p62-positive intranuclear inclusions are the pathological hallmark of NIID.

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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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Objective Although aerobic exercise tests on cycle ergometry have long been used for initial assessments of cases of suspected mitochondrial disease, the test parameters in patients with final diagnoses of other diseases via the widely used 15 W for 15 minutes exercise protocol have not been fully characterized. Methods We retrospectively reviewed all patients who underwent the test at our institution. We classified the patients with genetic diagnoses or those who met previously reported clinical criteria as having mitochondrial diseases and those with a final diagnosis of another disease as having other diseases.

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Introduction: Stress cardiomyopathy, or Takotsubo syndrome (TTS), is an acute and reversible syndrome developing in strong association with psychological or physiological stressors. While a surge in the circulating catecholamine level is suspected as one of its pathophysiologies, the contribution of treatment with sympathomimetic drugs to the development of TTS remains uncertain.

Methods: We conducted a disproportionality analysis using the Japanese Adverse Drug Event Report (JADER) database containing more than 500,000 patient cases recorded between April 2004 and March 2019, to detect TTS ('stress cardiomyopathy') as adverse event signals associated with adrenergic agonist drugs usage by calculating reporting odds ratio (ROR).

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Objective: To report the clinical, neuroimaging, and antibody associations in patients with autoimmune encephalitis (AE) and thymoma.

Methods: A retrospective cohort study of 43 patients was conducted. Antibody determination and immunoprecipitation to characterize novel antigens were performed using reported techniques.

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