Publications by authors named "Shigeo Murayama"

Objective: Neuronal Intranuclear Inclusion Disease (NIID) is a neurodegenerative disease affecting the central and peripheral nerves. We aimed to assess the pathophysiological features of peripheral nerve dysfunction in NIID.

Methods: We observed six unrelated NIID patients through clinical records, nerve conduction studies, and multiple measures of motor nerve excitability.

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Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated disease that mainly affects the peripheral nerves and nerve roots and typically presents with distal dominant motor and sensory disturbances as clinical symptoms. Central nervous system (CNS) demyelination with inflammation occurs infrequently in patients with CIDP. Here, we present a unique autopsy report of CIDP causing severe demyelination along the entire spinal cord.

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  • The choroid plexus plays a vital role in producing cerebrospinal fluid and regulating circadian rhythms, which can be affected by neurodegenerative diseases like Alzheimer's.
  • A study analyzed brain samples from patients with Alzheimer's, vascular dementia, Parkinson's disease, and multiple system atrophy, focusing on the morphology of choroid plexus epithelial cells.
  • Results showed no significant changes in epithelial cell measurements across the different disease groups, but age was positively correlated with cell size, suggesting that aging affects these cells regardless of neurodegenerative conditions.
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  • Researchers created a new Alzheimer’s disease (AD) model mouse using human tau protein to better understand microglial states related to tau pathology, which hasn't been thoroughly studied yet.
  • The study found that microglia associated with disease increased after tau accumulation, suggesting a shift from age-related microglia to a disease-associated profile in the brains of these model mice.
  • Advanced techniques like single-nucleus RNA sequencing and spatial transcriptomics were employed to highlight how tau propagation affects microglial behavior, paving the way for deeper insights into tau-related changes in the AD brain.
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  • Alzheimer's disease is marked by the buildup of amyloid β and tau proteins, leading to neuroinflammation primarily driven by activated glial cells, which worsens the condition.
  • Researchers found that the cannabinoid receptor type II (Cnr2/Cb2) is upregulated in both mouse models of Alzheimer's and in human brain tissue affected by the disease, suggesting a potential therapeutic role.
  • Administering JWH 133, a specific CB2 agonist, improved cognitive function in mice with Alzheimer's symptoms by reducing neuroinflammation and harmful astrocyte responses, indicating that targeting the CB2 receptor could be a promising strategy for treating Alzheimer's and other neurodegenerative diseases.
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  • A multicenter study in Japan began in 2014 to gather data on progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) to better understand their clinical features and identify potential biomarkers.
  • Initial assessments of 349 patients focused on symptoms, clinical scores (like the PSPRS), and factors affecting disease progression over eight years.
  • Results indicated that patients with Richardson's syndrome (RS) had better clinical scores compared to those with CBD, and cognitive dysfunction played a significant role in disease severity and progression.
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Background/objectives: Sporadic Creutzfeldt-Jakob disease (sCJD) is a fatal neurodegenerative disorder traditionally diagnosed based on the World Health Organization (WHO) criteria in 1998. Recently, Hermann et al. proposed updated diagnostic criteria incorporating advanced biomarkers to enhance early detection of sCJD.

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Here, we present an autopsy case of long-standing myotonic dystrophy type 1 (DM1) in a patient who developed a pancreatic intraductal papillary mucinous neoplasm (IPMN). DM1 is a progressive genetic disorder that affects multiple organs, including the respiratory muscles. Several nationwide registry-based cohort studies have suggested that patients with DM1 have an increased risk of developing pancreatic cancers such as pancreatic ductal adenocarcinoma (PDAC).

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Our previous cryogenic electron microscopy (cryoEM) analysis showed that the core structures of α-synuclein filaments accumulated in brains of patients diagnosed with dementia with Lewy bodies (DLB) and multiple system atrophy (MSA) patients are different. We analyzed the post-translational modifications (PTMs) in these filaments , and examined their relationship with the core filament structures and pathological features. Besides the common PTMs in MSA and DLB filaments, acetylation, methylation, oxidation and phosphorylation were frequently detected in MSA filaments, but not in DLB filaments.

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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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Identifying the properties of the rapid eye movement (REM) sleep circuitry and its relation to diseases has been challenging due to the neuronal heterogeneity of the brainstem. Here, we show in mice that neurons in the pontine sublaterodorsal tegmentum (SubLDT) that express corticotropin-releasing hormone-binding protein (Crhbp neurons) and project to the medulla promote REM sleep. Within the medullary area receiving projections from Crhbp neurons, neurons expressing nitric oxide synthase 1 (Nos1 neurons) project to the SubLDT and promote REM sleep, suggesting a positively interacting loop between the pons and the medulla operating as a core REM sleep circuit.

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  • - MOGAD (Myelin oligodendrocyte glycoprotein antibody-associated disease) shows a variety of clinical symptoms, one being encephalitis, along with diverse MRI imaging results, including a rare perivascular pattern recently reported.
  • - The study presents two cases where patients with MOGAD had similar MRI features and underwent brain biopsies, revealing signs of demyelination and inflammation, which were consistent with acute disseminated encephalomyelitis (ADEM).
  • - The findings indicate significant differences in axonal damage and cerebral atrophy between the two cases, suggesting the importance of brain biopsy for diagnosis and prognosis in MOGAD, even when imaging results are atypical.
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Neurodegenerative diseases are characterized by the abnormal filamentous assembly of specific proteins in the central nervous system. Human genetic studies have established a causal role for protein assembly in neurodegeneration. However, the underlying molecular mechanisms remain largely unknown, which is limiting progress in developing clinical tools for these diseases.

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Spleen tyrosine kinase (Syk), a non-receptor-type tyrosine kinase, has a wide range of physiological functions. A possible role of Syk in Alzheimer's disease (AD) has been proposed. We evaluated the localization of Syk in the brains of patients with AD and control participants.

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  • CHCHD2 and CHCHD10 are mitochondrial proteins associated with diseases like Parkinson's and ALS, with this study focusing on the CHCHD2 P14L variant linked to ALS.
  • The P14L variant mislocalizes CHCHD2 to the cytoplasm, impairing mitochondrial function and leading to degeneration, unlike its wild-type counterpart.
  • Additionally, this variant disrupts calcium buffering in neurons, triggering abnormal calcium dynamics and TDP-43 aggregation, which are indicators of ALS pathology.
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  • - The study investigates how well conventional MRI can differentiate corticobasal degeneration (CBD) from its mimics due to similar clinical features.
  • - Researchers analyzed the degree of brain atrophy and asymmetry in MRI images of 19 CBD patients and 16 patients with conditions that mimic CBD, like Alzheimer's and progressive supranuclear palsy.
  • - Findings suggest that specific patterns of atrophy and the presence of white matter hyperintensity can be used as imaging biomarkers to help diagnose CBD more accurately.
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Pathological hallmark of Alzheimer's disease (AD) is characterized by the accumulation and aggregation of amyloid β (Aβ) peptides into extracellular plaques of the brain. Clarification of the process of how soluble Aβ starts to assemble into amyloid fibrils is an essential step in elucidating the pathogenesis of AD. In our previous study, Aβ proteoforms including full-length Aβ40 and Aβ42/43 with N- and C-terminal truncated forms were visualized in postmortem brains from AD patients with matrix-assisted laser desorption/ionization-based mass spectrometry imaging (MALDI-MSI).

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Neurodegenerative diseases are characterised by the abnormal filamentous assembly of specific proteins in the central nervous system . Human genetic studies established a causal role for protein assembly in neurodegeneration . However, the underlying molecular mechanisms remain largely unknown, which is limiting progress in developing clinical tools for these diseases.

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Various forms of Parkinson's disease, including its common sporadic form, are characterized by prominent α-synuclein (αSyn) aggregation in affected brain regions. However, the role of αSyn in the pathogenesis and evolution of the disease remains unclear, despite vast research efforts of more than a quarter century. A better understanding of the role of αSyn, either primary or secondary, is critical for developing disease-modifying therapies.

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Leucine-rich repeat kinase 2 (LRRK2) is the most common gene responsible for familial Parkinson's disease (PD). The gene product of LRRK2 contains multiple protein domains, including armadillo repeat, ankyrin repeat, leucine-rich repeat (LRR), Ras-of-complex (ROC), C-terminal of ROC (COR), kinase, and WD40 domains. In this study, we performed genetic screening of LRRK2 in our PD cohort, detecting sixteen LRRK2 rare variants.

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