218 research outputs found

    Purification, Characterization, and Gene Expression of Rice Endo-beta-N-Acetylglucosaminidase, Endo-Os

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    In the endoplasmic reticulum-associated degradation system of plant and animal cells, high-mannose type free N-glycans (HMT-FNGs) are produced from misfolded glycoproteins prior to proteasomal degradation, and two enzymes, cytosolic peptide:N-glycanase (cPNGase) and endo-beta-N-acetylglucosaminidase (endo-beta-GlcNAc-ase), are involved in the deglycosylation. Although the physiological functions of these FNGs in plant growth and development remain to be elucidated, detailed characterization of cPNGase and endo-beta-GlcNAc-ase is required. In our previous work, we described the purification, characterization, and subcellular distribution of some plant endo-beta-GlcNAc-ases and preliminarily reported the gene information of rice endo-beta-GlcNAc-ase (Endo-Os). Furthermore, we analyzed the changes in gene expression of endo-beta-GlcNAc-ase during tomato fruit maturation and constructed a mutant line of Arabidopsis thaliana, in which the two endo-beta-GlcNAc-ase genes were knocked-out based on the Endo-Os gene. In this report, we describe the purification, characterization, amino acid sequence, and gene cloning of Endo-Os in detail. Purified Endo-Os, with an optimal pH of 6.5, showed high activity for high-mannose type N-glycans bearing the Man alpha 1-2Man alpha 1-3Man beta 1 unit; this substrate specificity was almost the same as that of other plant endo-beta-GlcNAc-ases, suggesting that Endo-Os plays a critical role in the production of HTM-FNGs in the cytosol. Electrospray ionization-mass spectrometry analysis of the tryptic peptides revealed 17 internal amino acid sequences, including the C terminus; the N-terminal sequence could not be identified due to chemical modification. These internal amino acid sequences were consistent with the amino acid sequence (UniProt ID: Q5W6R1) deduced from the Oryza sativa cDNA clone AK112067 (gene ID: Os05g0346500). Recombinant Endo-Os expressed in Escherichia coli using cDNA showed the same enzymatic properties as those of native Endo-Os

    Single-Image Super-Resolution Improvement of X-ray Single-Particle Diffraction Images Using a Convolutional Neural Network

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    Femtosecond X-ray pulse lasers are promising probes for the elucidation of the multiconformational states of biomolecules because they enable snapshots of single biomolecules to be observed as coherent diffraction images. Multi-image processing using an X-ray free-electron laser has proven to be a successful structural analysis method for viruses. However, the performance of single-particle analysis (SPA) for flexible biomolecules with sizes ≤100 nm remains difficult. Owing to the multiconformational states of biomolecules and noisy character of diffraction images, diffraction image improvement by multi-image processing is often ineffective for such molecules. Herein, a single-image super-resolution (SR) model was constructed using an SR convolutional neural network (SRCNN). Data preparation was performed in silico to consider the actual observation situation with unknown molecular orientations and the fluctuation of molecular structure and incident X-ray intensity. It was demonstrated that the trained SRCNN model improved the single-particle diffraction image quality, corresponding to an observed image with an incident X-ray intensity (approximately three to seven times higher than the original X-ray intensity), while retaining the individuality of the diffraction images. The feasibility of SPA for flexible biomolecules with sizes ≤100 nm was dramatically increased by introducing the SRCNN improvement at the beginning of the various structural analysis schemes

    Treatment resistance of rheumatoid arthritis relates to infection of periodontal pathogenic bacteria: a case-control cross-sectional study

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    Recent studies have shown that periodontitis is associated with rheumatoid arthritis (RA) and periodontal bacteria, such as Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) are involved in the pathogenesis of RA via citrullinated proteins. Smoking has also been shown to be involved in the pathogenesis of RA; however, the extent of this involvement is still poorly understood. In addition, RA and polymyalgia rheumatica (PMR) are sometimes difficult to differentiate; however, the relationship between PMR and the factors from smoking and periodontal bacteria is unclear. The aim of this study was to clarify the relationship between periodontal pathogenic bacterial infections and smoking in patients with RA or PMR. This case-control study included 142 patients with untreated RA or PMR. This study evaluated the serum antibody titers against periodontal pathogenic bacterial antigens and an anti-citrullinated peptide antibody (ACPA). In patients with RA, the relationship between antibody titers and disease activity of RA and response after 3 months of treatment was also investigated. Additionally, the effects of smoking were evaluated. Although there was no significant difference in serum antibody titer against periodontal pathogenic bacteria between the ACPA-positive RA group and the ACPA-negative PMR group, we found an association between the elevated antibody titer against Pg and the degree of ACPA value, especially between negative group and high-value positive group (>= 100 U/mL). The antibody titers against Aa and Pg did not differ depending on disease activity score 28 (DAS28) at baseline; however, patients with high antibody titers had poor RA therapeutic response as judged by DAS28 after 3 months. We could not find any association between smoking and any of these parameters. Periodontal pathogenic bacteria, especially Pg, are associated with elevated ACPA levels. Our findings suggest that Pg and Aa infections interfere with the therapeutic response of RA

    The Possible Role of TASK Channels in Rank-Ordered Recruitment of Motoneurons in the Dorsolateral Part of the Trigeminal Motor Nucleus.

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    Because a rank-ordered recruitment of motor units occurs during isometric contraction of jaw-closing muscles, jaw-closing motoneurons (MNs) may be recruited in a manner dependent on their soma sizes or input resistances (IRs). In the dorsolateral part of the trigeminal motor nucleus (dl-TMN) in rats, MNs abundantly express TWIK (two-pore domain weak inwardly rectifying K channel)-related acid-sensitive-K(+) channel (TASK)-1 and TASK3 channels, which determine the IR and resting membrane potential. Here we examined how TASK channels are involved in IR-dependent activation/recruitment of MNs in the rat dl-TMN by using multiple methods. The real-time PCR study revealed that single large MNs (>35 μm) expressed TASK1 and TASK3 mRNAs more abundantly compared with single small MNs (15-20 μm). The immunohistochemistry revealed that TASK1 and TASK3 channels were complementarily distributed in somata and dendrites of MNs, respectively. The density of TASK1 channels seemed to increase with a decrease in soma diameter while there were inverse relationships between the soma size of MNs and IR, resting membrane potential, or spike threshold. Dual whole-cell recordings obtained from smaller and larger MNs revealed that the recruitment of MNs depends on their IRs in response to repetitive stimulation of the presumed Ia afferents. 8-Bromoguanosine-cGMP decreased IRs in small MNs, while it hardly changed those in large MNs, and subsequently decreased the difference in spike-onset latency between the smaller and larger MNs, causing a synchronous activation of MNs. These results suggest that TASK channels play critical roles in rank-ordered recruitment of MNs in the dl-TMN

    Efficacy and safety of micafungin in empiric and D-index-guided early antifungal therapy for febrile neutropenia ; A subgroup analysis of the CEDMIC trial

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    Objectives: The D-index is defined as the area over the neutrophil curve during neutropenia. The CEDMIC trial confirmed the noninferiority of D-index-guided early antifungal therapy (DET) using micafungin to empirical antifungal therapy (EAT). In this study, we evaluated the efficacy and safety of micafungin in these settings. Methods: From the CEDMIC trial, we extracted 67 and 113 patients who received micafungin in the DET and EAT groups, respectively. Treatment success was defined as the fulfilment of all components of a five-part composite end point. Fever resolution was evaluated at seven days after the completion of therapy. Results: The proportion of high-risk treatments including induction chemotherapy for acute leukemia and allogeneic hematopoietic stem cell transplantation was significantly higher in the DET group than in the EAT group (82.1% vs. 52.2%). The efficacy of micafungin was 68.7% (95%CI: 56.2–79.4) and 79.6% (71.0–86.6) in the DET and EAT groups, respectively. When we focused on high-risk treatments, the efficacy was 69.1% (55.2–80.9%) and 78.0% (65.3–87.7%), respectively (P = 0.30). There was no significant difference in any of the 5 components between the two groups. Conclusions: The efficacy of micafungin in patients undergoing high-risk treatment was not strongly impaired in DET compared to that in EAT

    THYROID DYSFUNCTION FOLLOWING ALPHA-INTERFERON TREATMENT FOR CHRONIC HEPATITIS C

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    In order to evaluate the influnces of IFNα on thyroid function, thyroid-stimulating hormone (TSH), total thyroxine (T4), free T4, tri-iodothyronine (T3), and thyroxine-binding globulin were examined in IFNα-treated 351 patients with chronic hepatitis C before and during therapy. As therapy, either 3 million units (MU) of human lymphoblastoid IFNα or 9MU of recombinant IFNα2a was administrated daily for the initial two weeks followed by three times a week for 22 weeks. There were nine patients showing thyroid dysfunction during IFNα therapy. They consist of one relapse of Graves' disease, one relapse of Hashimoto thyroiditis, one development of apparent thyroid insufficiency from subclinical hypothyroidism, five cases with transient hyperthyroidism and one case with transient hypothyroidism. T4 and T3 levels in most patients who transiently developed thyroid dysfunction were normalized spontaneously after the discontinuation of IFNα. Thyroid-related autoantibodies were positive in 4 patients before IFNα therapy and newly developed in one patient during therapy. Attention should be paid first to the previous histories of autoimmune thyroid diseases and the existence of thyroid-related autoantibodies for the prediction of development of thyroid dysfunction during IFNα therapy. In addition, serial examinations of TSH, T3 and T4 should be also necessary for early detection of transient thyroid dysfunction during IFNα therapy

    Salvage Haploidentical Transplantation Using Low-dose ATG for Early Disease Relapse after First Allogeneic Transplantation: A Retrospective Single-center Review

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    Second allogeneic stem cell transplantation (allo-SCT) is a potentially curative therapy for patients who relapse after first allo-SCT. Human leukocyte antigen (HLA)-haploidentical related donors provide the broad opportunity to conduct second SCT at the appropriate time, but the efficacy of second SCT from haploidentical donors after relapse has not been established. We retrospectively analyzed the records of 33 patients who underwent second SCT. Twenty patients underwent haplo-SCT with low-dose antithymocyte globulin (ATG), and the other 13 patients underwent conventional- SCTs, including HLA-matched related peripheral blood, unrelated bone marrow or cord blood. Three years after the second SCT, the overall survival (OS) and progression-free survival (PFS) of all patients were 32.5% and 23.9%. Multivariate analyses indicated that non-complete response at second SCT, less than 1-year interval to relapse after first- SCT, and total score ≥ 3 on the hematopoietic cell transplantation-specific comorbidity index were significantly associated with a lower PFS rate. The haplo- and conventional- SCT groups showed equivalent results regarding OS, PFS, cumulative incidences of relapse, non-relapse mortality and graft-versus-host disease. The neutropenic period after transplantation was significantly shorter in haplo- SCT than conventional- SCT (10.5 days vs. 16 days, p=0.001). Our analysis revealed that haplo-SCT could be an alternative therapeutic option for relapsed patients after first SCT
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