Publications by authors named "Hirokawa K"

Diffuse alveolar hemorrhage (DAH) is a rare and severe complication of IgA vasculitis (IgAV). Although glucocorticoids and immunosuppressive agents are used for its treatment, there is no consensus on the optimal form of treatment. We herein report the case of a 53-year-old, female patient with IgAV.

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Aim: This study investigated the association between COVID-19 pandemic-related work environment changes and suspected post-traumatic stress disorder (PTSD) in Japanese workers.

Methods: A web survey of 1104 workers was conducted in Japan between February 24 and March 2, 2021. The Japanese version of the Impact of Event Scale-Revised and questions regarding work environments and COVID-19 pandemic-related lifestyle changes were used.

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Article Synopsis
  • Women with high levels of autistic traits may face greater health risks during pregnancy, especially those diagnosed with autism spectrum disorder (ASD), leading to worse birth outcomes.
  • The study aimed to explore the relationship between maternal autistic traits and the likelihood of negative birth outcomes using data from a large, nationwide cohort in Japan.
  • Results showed that increased scores of autistic traits were linked to a higher risk of adverse outcomes like preterm births and babies born small for their gestational age, even after considering other maternal health factors.
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The mammalian brain is composed of diverse neuron types that play different functional roles. Recent single-cell RNA sequencing approaches have led to a whole brain taxonomy of transcriptomically-defined cell types, yet cell type definitions that include multiple cellular properties can offer additional insights into a neuron's role in brain circuits. While the Patch-seq method can investigate how transcriptomic properties relate to the local morphological and electrophysiological properties of cell types, linking transcriptomic identities to long-range projections is a major unresolved challenge.

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The Allen Mouse Brain Connectivity Atlas consists of anterograde tracing experiments targeting diverse structures and classes of projecting neurons. Beyond regional anterograde tracing done in C57BL/6 wild-type mice, a large fraction of experiments are performed using transgenic Cre-lines. This allows access to cell-class-specific whole-brain connectivity information, with class defined by the transgenic lines.

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Neocortical spiking dynamics control aspects of behavior, yet how these dynamics emerge during motor learning remains elusive. Activity-dependent synaptic plasticity is likely a key mechanism, as it reconfigures network architectures that govern neural dynamics. Here, we examined how the mouse premotor cortex acquires its well-characterized neural dynamics that control movement timing, specifically lick timing.

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Introduction: Clinically, Alzheimer's disease (AD) is a syndrome with a spectrum of various cognitive disorders. There is a complete dissociation between the pathology and the clinical presentation. Therefore, we need a disruptive new approach to be able to prevent and treat AD.

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This study investigates the effects of a third-party certification policy for restaurants (including bars) that comply with indoor infection-prevention measures on COVID-19 cases and economic activities. We focus on the case of Yamanashi Prefecture in Japan, which introduced a third-party certification policy that accredits facilities, predominantly restaurants, that comply with the designated guidelines. We employ a difference-in-differences design for each of our epidemiological and economic analyses.

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Article Synopsis
  • The claustrum (CLA) is a key brain structure that connects various regions, but its detailed anatomy and neuron types in mice are still not fully understood.
  • Researchers used advanced techniques to map the inputs and outputs of the CLA, revealing that the prefrontal cortex has the most diverse types of neurons connecting to it.
  • The study identified nine distinct types of principal neurons in the CLA that target specific areas of the cortex, setting the stage for future research on the CLA's cellular functions.
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Identification of structural connections between neurons is a prerequisite to understanding brain function. Here we developed a pipeline to systematically map brain-wide monosynaptic input connections to genetically defined neuronal populations using an optimized rabies tracing system. We used mouse visual cortex as the exemplar system and revealed quantitative target-specific, layer-specific and cell-class-specific differences in its presynaptic connectomes.

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Aim: This cross-sectional study aimed to investigate the associations between salivary testosterone concentrations and cognitive function in 70-year-old Japanese elderly people without dementia and stroke.

Methods: Participants were 197 Japanese community-dwelling people aged 69-71 years. Their salivary samples were collected, and their cognitive function was assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J).

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Low testosterone concentrations are associated with disrupted sleep, and high levels of cortisol, which is elevated in response to stress, lead to insomnia. This study aimed to investigate the associations of testosterone and cortisol concentrations with sleep quality and to examine potential interactions between them in Japanese working men. This study was a cross-sectional design, and testosterone and cortisol concentrations in blood were the exposure variables and sleep parameters were the outcome variables.

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Breastfeeding women may experience various health issues that require medication. This survey aimed to gain insights into the use of nonprescription and prescription drugs by breastfeeding women in Japan. A cross-sectional study involving women with children aged under two years was conducted in Fukuoka, Japan.

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Organismal ageing is associated with many physiological changes, including differences in the immune system of most animals. These differences are often considered to be a key cause of age-associated diseases as well as decreased vaccine responses in humans. The most often cited vaccine failure is seasonal influenza, but, while it is usually the case that the efficiency of this vaccine is lower in older than younger adults, this is not always true, and the reasons for the differential responses are manifold.

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Cadmium selenide quantum dots (QDs) are fluorescent and electron-dense nanoparticles. When used as reporter of immunolabeling, this dual visibility is essential for direct comparison of its fluorescent signals on light microscopy (LM) and their ultrastructrual counterparts on electron microscopy (EM) as correlative light and electron microscopy (CLEM). To facilitate EM recognition, QDs on EM grid were gold enhanced, which increased their size and electron density.

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In a brain, it is considered that the synchronous activity of neurons expresses a representation of information. Hebb named the synchronous active group of neurons "Cell Assembly". In this study, we hypothesized that a repeatedly expressed pattern is a cell assembly representing a certain kind of information and attempted to extract such "Cell Assembly" by X-means clustering based on spatiotemporal continuity of spontaneous spikes.

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Dendritic and axonal morphology reflects the input and output of neurons and is a defining feature of neuronal types, yet our knowledge of its diversity remains limited. Here, to systematically examine complete single-neuron morphologies on a brain-wide scale, we established a pipeline encompassing sparse labelling, whole-brain imaging, reconstruction, registration and analysis. We fully reconstructed 1,741 neurons from cortex, claustrum, thalamus, striatum and other brain regions in mice.

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An essential step toward understanding brain function is to establish a structural framework with cellular resolution on which multi-scale datasets spanning molecules, cells, circuits and systems can be integrated and interpreted. Here, as part of the collaborative Brain Initiative Cell Census Network (BICCN), we derive a comprehensive cell type-based anatomical description of one exemplar brain structure, the mouse primary motor cortex, upper limb area (MOp-ul). Using genetic and viral labelling, barcoded anatomy resolved by sequencing, single-neuron reconstruction, whole-brain imaging and cloud-based neuroinformatics tools, we delineated the MOp-ul in 3D and refined its sublaminar organization.

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The inflammaging concept was introduced in 2000 by Prof. Franceschi. This was an evolutionary or rather a revolutionary conceptualization of the immune changes in response to a lifelong stress.

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Objective: The present study investigated associations between occupation, job stress, and salivary cortisol levels after psychological tasks.

Methods: We examined 766 (273 men and 493 women) healthy employed Japanese participants aged 21 to 68 years (mean age = 46.4 years, standard deviation = 8.

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The role of oligodendrocyte lineage cells, the largest glial population in the adult central nervous system (CNS), in the pathogenesis of Alzheimer's disease (AD) remains elusive. Here, we developed a culture method for adult oligodendrocyte progenitor cells (aOPCs). Fibroblast growth factor 2 (FGF2) promotes survival and proliferation of NG2 aOPCs in a serum-free defined medium; a subpopulation (~5%) of plexin-B3 aOPCs was also found.

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Background: Alzheimer's disease (AD) is the most common neurodegenerative disease ultimately manifesting as clinical dementia. Despite considerable effort and ample experimental data, the role of neuroinflammation related to systemic inflammation is still unsettled. While the implication of microglia is well recognized, the exact contribution of peripheral monocytes/macrophages is still largely unknown, especially concerning their role in the various stages of AD.

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Alzheimer's disease (AD) is the most common form of dementia and aging is the most common risk factor for developing the disease. The etiology of AD is not known but AD may be considered as a clinical syndrome with multiple causal pathways contributing to it. The amyloid cascade hypothesis, claiming that excess production or reduced clearance of amyloid-beta (Aβ) and its aggregation into amyloid plaques, was accepted for a long time as the main cause of AD.

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