Publications by authors named "HAMAZAKI Y"

Age-associated differences in the effect of repetitive vaccination, particularly on memory T-cell and B-cell responses, remain unclear. While older adults (aged ≥65 years) exhibited enhanced IgG responses following COVID-19 mRNA booster vaccination, they produced fewer spike-specific circulating follicular helper T cells-1 than younger adults. Similarly, the cytotoxic CD8 T-cell response remained diminished with reduced PD-1 expression even after booster vaccination compared with that in younger adults, suggesting impaired memory T-cell activation in older adults.

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Article Synopsis
  • The COVID-19 pandemic has led to significant health impacts, with severe cases often linked to factors like age and underlying health conditions, prompting the exploration of syndecan-1 (SDC-1) as a potential biomarker for predicting outcomes.
  • A retrospective study analyzed COVID-19 patients in Fukushima, Japan, measuring SDC-1 levels alongside clinical data to correlate with disease severity and mortality rates.
  • Results indicated that higher SDC-1 levels were associated with worse outcomes, suggesting its utility in predicting mortality within 28 days of hospitalization, although further research is necessary to confirm its long-term predictive value.
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The comparative analysis between humans and non-human primates is an instrumental approach for elucidating the evolutional traits and disease propensity of humans. However, in primates, cross-species analyses of their developmental events have encountered constraints because of the ethical and technical limitations in available sample collection, sequential monitoring, and manipulations. In an endeavor to surmount these challenges, in recent years, induced pluripotent stem cells (iPSCs) have garnered escalating interest as an in vitro tool for cross-species analyses between humans and non-human primates.

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As humans' closest living relatives, chimpanzees offer valuable insights into human evolution. However, technical and ethical limitations hinder investigations into the molecular and cellular foundations that distinguish chimpanzee and human traits. Recently, induced pluripotent stem cells (iPSCs) have emerged as a novel model for functional comparative studies and provided a non-invasive alternative for studying embryonic phenomena.

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Middle-down proteomics (MDP) is an analytical approach in which protein samples are digested with proteases such as Glu-C to generate large peptides (>3 kDa) that are analyzed by mass spectrometry (MS). This method is useful for characterizing high-molecular-weight proteins that are difficult to detect by top-down proteomics (TDP), in which intact proteins are analyzed by MS. In this study, we applied GeLC-FAIMS-MS, a multidimensional separation workflow that combines gel-based prefractionation with LC-FAIMS MS, for deep MDP.

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  • This study investigates the relationship between contrast media volume (CMV) and contrast-induced nephropathy (CIN) in patients with chronic kidney disease (CKD) undergoing percutaneous coronary intervention (PCI) for chronic total occlusion (CTO).
  • Results show that a minimum CMV of 50 mL or less significantly reduces the incidence of CIN compared to a higher CMV (1.0% vs. 4.1%, p = 0.03).
  • Additionally, patients in the minimum CMV group experienced higher success rates (96.8% vs. 90.3%) and fewer complications (3.1% vs. 7.1%) as well as a greater use of the
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Common marmosets usually give birth to twins and form a social group consisting of a breeding couple and pairs of same-aged siblings. The twins may engage in the first agonistic fights between them, twin-fights (TFs), during adolescence. This study investigated the TFs based on records accumulated in our captive colony over 12 years to elucidate the proximate causations that trigger the TFs.

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Cold agglutinin disease (CAD) is a rare cold autoimmune haemolytic anaemia (cAIHA) caused by IgM antibodies recognizing I antigens on erythrocytes. cAIHA is now mainly classified into two types: primary CAD and cold agglutinin syndrome (CAS). CAS develops in association with the underlying disease, which is most commonly malignant lymphoma.

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Whether age-associated defects in T cells impact the immunogenicity and reactogenicity of mRNA vaccines remains unclear. Using a vaccinated cohort (n = 216), we demonstrated that older adults (aged ≥65 years) had fewer vaccine-induced spike-specific CD4 T cells including CXCR3 circulating follicular helper T cells and the T1 subset of helper T cells after the first dose, which correlated with their lower peak IgG levels and fewer systemic adverse effects after the second dose, compared with younger adults. Moreover, spike-specific T1 cells in older adults expressed higher levels of programmed cell death protein 1, a negative regulator of T cell activation, which was associated with low spike-specific CD8 T cell responses.

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The Task Force on Rotational Atherectomy of the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT) proposed the expert consensus document to summarize the techniques and evidences regarding rotational atherectomy (RA) in 2020. Because the revascularization strategy to severely calcified lesions is the hottest topic in contemporary percutaneous coronary intervention (PCI), many evidences related to RA have been published since 2020. Latest advancements have been incorporated in this updated expert consensus document.

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Non-human primates are important models for investigations of neural development and evolution, and the use of Japanese macaque monkeys has especially contributed to the advancement of neuroscience studies. However, these studies are restricted by the number of animals able to be evaluated and the invasiveness of the methodologies. Induced pluripotent stem cells (iPSCs) can provide an alternative strategy for investigating neural development in vitro.

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Picrasma quassioides is used as a bittersweet stomach medicine. Because it is a natural product obtained from various geographical regions, the production area is important when P. quassioides is used as a crude drug.

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The new 2018 classification of periodontal diseases is reported to be related to tooth loss due to periodontal disease (TLPD) during supportive periodontal therapy (SPT). However, few reports have evaluated this relationship for Asians or have analyzed the association of the new classification and TLPD by distinguishing between active periodontal therapy (APT) and SPT. In this study, we retrospectively applied the new classification to 607 Japanese periodontitis patients and examined the relationship between the new classification and annual TLPD rates per patient during the respective periods.

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Age is a major risk factor for COVID-19 severity, and T cells play a central role in anti-SARS-CoV-2 immunity. Because SARS-CoV-2-cross-reactive T cells have been detected in unexposed individuals, we investigated the age-related differences in pre-existing SARS-CoV-2-reactive T cells. SARS-CoV-2-reactive CD4 T cells from young and elderly individuals were mainly detected in the central memory fraction and exhibited similar functionalities and numbers.

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Cutibacterium acnes plays roles in both acne disease and healthy skin ecosystem. We observed that mutations in the tir-1/SARM1 and p38 MAPK cascade genes significantly shortened Caenorhabditis elegans lifespan upon C. acnes SK137 infection.

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Article Synopsis
  • * Researchers found that signaling between CD153+ T cells and CD30+ B cells plays a key role in expanding TLTs, especially in aged kidneys after injury.
  • * Disrupting CD153 or CD30 signaling leads to fewer B cells and reduced TLT formation, suggesting these pathways could be targeted to slow down kidney disease progression.
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  • Cutibacterium acnes is a bacteria found on human skin that can both help maintain skin health and contribute to skin issues like acne, depending on the strain.
  • Research showed that some strains of C. acnes can shorten the lifespan of the model organism C. elegans, while strain HL110PA4 did not affect lifespan and actually improved resistance against the bacterial pathogen Staphylococcus aureus.
  • The study found that the TIR-1 and p38 MAPK signaling pathways are important for how C. acnes helps protect against infections, indicating a complex interplay between skin-resident bacteria and host immune responses.
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Prostaglandin E (PGE) promotes tumor progression through evasion of antitumor immunity. In stark contrast to cyclooxygenase-dependent production of PGE, little is known whether PGE secretion is regulated within tumor tissues. Here, we show that VEGF-dependent release of thromboxane A (TXA) triggers Ca transients in tumor cells, culminating in PGE secretion and subsequent immune evasion in the early stages of tumorigenesis.

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  • - A mutation in the Janus kinase 2 gene, which replaces valine with phenylalanine at position 617, is linked to increased inflammation, particularly higher IL-6 production in myeloid cells
  • - Research showed that this mutation raises levels of p-STAT3 in macrophages, enhancing IL-6 production, but blocking STAT3 with a specific inhibitor significantly reduces IL-6 levels
  • - The mutation also stabilizes the PKM1 protein, preventing its degradation, which ultimately activates STAT3 and promotes further IL-6 production, revealing a complex interaction between these molecular players in inflammatory response.
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Aim: This study investigated whether the small dense low-density lipoprotein cholesterol (sd-LDL-c) level is associated with the rapid progression (RP) of non-culprit coronary artery lesions and cardiovascular events (CE) after acute coronary syndrome (ACS).

Methods: In 142 consecutive patients with ACS who underwent primary percutaneous coronary intervention for the culprit lesion, the sd-LDL-c level was measured using a direct homogeneous assay on admission for ACS and at the 10-month follow-up coronary angiography. RP was defined as a progression of any pre-existing coronary stenosis and/or stenosis development in the initially normal coronary artery.

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Rotational atherectomy (RA) has been widely used for percutaneous coronary intervention (PCI) to severely calcified lesions. As compared to other countries, RA in Japan has uniquely developed with the aid of greater usage of intravascular imaging devices such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT). IVUS has been used to understand the guidewire bias and to decide appropriate burr sizes during RA, whereas OCT can also provide the thickness of calcification.

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T-cell development depends on the thymic microenvironment, in which endothelial cells (ECs) play a vital role. Interestingly, vascular permeability of the thymic cortex is lower than in other organs, suggesting the existence of a blood-thymus barrier (BTB). On the other hand, blood-borne molecules and dendritic cells bearing self-antigens are accessible to the medulla, facilitating central tolerance induction, and continuous T-precursor immigration and mature thymocyte egress occur through the vessels at the cortico-medullary junction (CMJ).

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Background: This prospective randomized multicenter open-label trial evaluated whether sodium-glucose cotransporter-2 inhibitor (SGLT2-i) improves left ventricular (LV) pump function and suppresses elevation of LV filling pressure (LVFP) and right ventricular systolic pressure (RVSP) during exercise in type 2 diabetes mellitus (T2DM) patients.

Methods and results: Based on HbA1c and LV ejection fraction, 78 patients with poorly controlled T2DM were randomly assigned to D-group (dapagliflozin 5 mg/day add-on) or C-group (conventional therapy add-on). Physical examination, home and office blood pressure examination, blood tests, and echocardiography at rest and during ergometer exercise were performed at baseline and at 1.

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