Publications by authors named "Seiji Tsuboi"

Bioactive peptides with various health benefits have been reported from rice protein hydrolysates. We previously showed that rice-derived peptides (RP) increased intracellular glutathione levels and induced the expression of γ-glutamylcysteine synthetase, which is regulated by nuclear transcription factor-erythroid 2-related factor 2 (Nrf2). Heme oxygenase-1 (HO-1) is an important Nrf2 downstream antioxidant enzyme that protects against oxidative stress.

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Objective: Glucocorticoids are important drugs used to treat rheumatoid arthritis. We recommend glucocorticoid discontinuation as soon as possible given the associated side-effects, but many patients continue to take oral glucocorticoids long-term. The present study aimed to explore factors associated with glucocorticoid discontinuation at 52 weeks after initiating biological disease-modifying antirheumatic drugs (bDMARDs).

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Glutathione, the most abundant intracellular antioxidant, protects cells against reactive oxygen species induced oxidative stress and regulates intracellular redox status. We previously demonstrated that yellow Chinese chive (ki-nira) increased the intracellular glutathione levels. Acetaminophen (APAP) is a commonly used analgesic.

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We previously showed that commercially available rice peptide Oryza Peptide-P60 (OP60) increased the intracellular glutathione levels. This study aimed to evaluate the antioxidant potential of this peptide and assess its mechanism of action. Pretreatment of HepG2 cells with OP60 reduced the cytotoxicity caused by HO or acetaminophen (APAP) (47.

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Introduction/objectives: Discontinuation of biologic therapy in rheumatoid arthritis is attributable to various reasons, with the most important cause being insufficient response. In this study, we investigated the association between rheumatoid factor (RF) and anti-citrullinated protein autoantibody (ACPA) status and the discontinuation of tumor necrosis factor inhibitors (TNFi) therapy due to insufficient response in bio-naïve rheumatoid arthritis (RA) patients.

Method: This study included patients enrolled in the Tsurumai Biologic Communication Registry in Japan.

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Objective: To compare the clinical outcomes of abatacept between rheumatoid arthritis patients with and without concomitant methotrexate (MTX) treatment in daily clinical practice.

Methods: A retrospective cohort study was performed using data from a multicentre registry. A total of 176 consecutive rheumatoid arthritis patients treated with abatacept were included.

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The aim of this study was to assess abatacept in rheumatoid arthritis (RA) patient. Patients (20 men, 89 women, aged 61.9 ± 10.

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To study the clinical effectiveness and long-term retention rate of abatacept (ABA) in elderly rheumatoid arthritis (RA) patients in daily clinical practice. A retrospective cohort study was performed using data from a multicenter registry. Our study population comprised 500 consecutive RA patients treated with ABA.

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Acetaminophen is a commonly used analgesic. However, an overdose of acetaminophen causes severe hepatotoxicity via depletion of hepatic glutathione. Here, we investigated the protective effects of sake lees hydrolysate against acetaminophen-induced hepatotoxicity in mice.

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Glutathione (GSH) is an ubiquitous thiol-containing tripeptide, which plays important roles in cellular protection from oxidative stress. In our search for a dietary source that can increase GSH levels, we discovered that a 24 h treatment of HepG2 cells with rice bran protein hydrolysate (RBPH), prepared by Umamizyme G-catalyzed hydrolysis, increased the GSH content in a dose-dependent manner. RBPH elevated the expression levels of γ-glutamylcysteine synthetase (γ-GCS), which constitutes the rate-limiting enzyme of GSH synthesis, and of another two enzymes, hemeoxygenase-1 (HO-1) and reduced nicotinamide adenine dinucleotide (phosphate): quinone oxidoreductase 1 (NQO1).

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Glutathione, the most abundant intracellular antioxidant, protects cells against reactive oxygen species induced oxidative stress and regulates intracellular redox status. We found that rice peptides increased intracellular glutathione levels in human hepatoblastoma HepG2 cells. Acetaminophen is a commonly used analgesic.

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Long-period ground motions in plain and basin areas on land can cause large-scale, severe damage to structures and buildings and have been widely investigated for disaster prevention and mitigation. However, such motions in ocean-bottom areas are poorly studied because of their relative insignificance in uninhabited areas and the lack of ocean-bottom strong-motion data. Here, we report on evidence for the development of long-period (10-20 s) motions using deep ocean-bottom data.

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Responsiveness to methotrexate (MTX), the "anchor drug" for treating rheumatoid arthritis (RA), varies among individual patients. In this study we investigated the effects of folate transporter gene expression levels on disease activity among 56 Japanese patients with RA who were undergoing MTX therapy. We also assessed gene expression levels for 15 healthy control subjects.

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Objectives: Tacrolimus (TAC) and abatacept (ABT) inhibit T-cells via different mechanisms and, in combination, may be effective against rheumatoid arthritis. However, they may also disrupt normal immune functions. We compared the efficacy and safety of ABT administered to patients in combination with TAC, methotrexate (MTX), or other drugs.

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Objective: Only a few studies have assessed predictive factors for the long-term efficacy of abatacept. This study aimed to provide clinical evidence of an adequate observational period for predicting low disease activity (LDA) achievement at 52 weeks in RA patients treated with abatacept.

Methods: Participants were all patients registered in a Japanese multicentre registry who were treated with abatacept and had at least 52 weeks of follow-up (n = 254).

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Favourable clinical results in rheumatoid arthritis (RA) patients with high disease activity (HDA) are difficult to achieve. This study evaluated the clinical efficacy of abatacept according to baseline disease activity compared to adalimumab and tocilizumab. This study included all patients registered in a Japanese multicenter registry treated with abatacept (n = 214), adalimumab (n = 175), or tocilizumab (n = 143) for 24 weeks.

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Objectives: The purpose of this study was to examine the treatment retention and efficacy of abatacept, the first member of a new class of biologic agents, in Japanese rheumatoid arthritis (RA) patients during clinical practice.

Methods: A retrospective multicenter study was conducted with patients who underwent abatacept therapy for 24 weeks (n = 143).

Results: Patients at baseline had a mean age of 63.

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  Methotrexate (MTX) exhibits large inter-individual and inter-ethnic differences in the dose required for its anti-rheumatic effect. To maintain low disease activity, patients may require increased MTX doses or co-administration of biologic disease-modifying anti-rheumatic drugs (bDMARDs). The availability of a marker predicting the effect of MTX will make it possible to increase the MTX dose and prescribe bDMARDs to patients at an early stage.

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A novel single-nucleotide polymorphism (SNP) in the 3'-untranslated region of the human dihydrofolate reductase (DHFR) gene with enhanced expression was identified in 2001. In 2007, it was reported that this SNP, DHFR C829T, was located close to a microRNA binding site and contributed to the stability of mRNA. Many researchers have analyzed this SNP in several races including Asians and Caucasians.

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Four rheumatoid arthritis patients (three women and one man) who had a history of prosthetic joint infection were treated with anti-tumor necrosis factor (TNF) agents after treatment of the infection. The anti-TNF therapy was subsequently discontinued in three patients. The reason for discontinuation was not the reactivation of infection, but disseminated tuberculosis, Pneumocystis jiroveci pneumonia, and interstitial pneumonia, respectively.

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Dihydrofolate reductase gene (DHFR) 19-bp deletion polymorphisms result in varied DHFR enzymatic activity affecting the risk for preterm delivery, spina bifida, and the efficacy of methotrexate (MTX). Ethnic differences in DHFR 19-bp polymorphisms may be responsible for the divergent findings in previous genetic studies. We compared genotype and allele frequency of DHFR intronic 19-bp deletion polymorphisms in ethnically homogenous East Asians (from Japan) and others by polymerase chain reaction assay conducted on 277 healthy Japanese individuals.

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Hyperhomocysteinemia is a known risk factor of cardiovascular disease. Homocysteine has been also linked to inflammation in rheumatoid arthritis (RA). In this study, we investigated the relationship between plasma homocysteine levels and single nucleotide polymorphism (SNP) of the gene coding for methylenetetrahydrofolate reductase (MTHFR), an enzyme involved in the biosynthesis of homocysteine, and the correlation between the plasma homocysteine levels and generally used inflammatory markers (C-reactive protein, erythrocyte sedimentation rate and matrix metalloproteinase-3) in 96 Japanese patients with RA.

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Rheumatoid arthritis (RA) is a chronic disease characterized by the painful joints, inflammation, uncontrolled proliferation of synovial tissue and multisystem comorbidities. Weekly low-dose methotrexate (MTX) has been established as effective treatment in RA patients. MTX is converted to gamma-glutamyl polyglutamates, an active form of MTX, through the action of folylpolyglutamate synthetase in the cells.

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We gave preoperative blood transfusions to 37 patients with rheumatoid arthritis (RA) and 35 patients with osteoarthritis (OA), including some whose baseline hemoglobin level was less than 10 g/dl. Transfusion packs can preserve whole blood containing citrate phosphate dextrose (CPD) for 3 weeks. The baseline hemoglobin level of RA cases was 10.

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Streptomyces griseus leucine aminopeptidase (SGAP), which has two zinc atoms in its active site, is clinically important as a model for understanding the structure and mechanism of action of other metallopeptidases. SGAP is a calcium-activated and calcium-stabilized enzyme, and its activation by calcium correlates with substrate specificity. In our previous study, we found a non-calcium-modulated leucine aminopeptidase secreted by Streptomyces septatus, the primary structure of which showed 71% identity with SGAP.

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