17 research outputs found

    Crucial role of nitric oxide synthases system in endothelium-dependent hyperpolarization in mice

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    The endothelium plays an important role in maintaining vascular homeostasis by synthesizing and releasing several relaxing factors, such as prostacyclin, nitric oxide (NO), and endothelium-derived hyperpolarizing factor (EDHF). We have previously demonstrated in animals and humans that endothelium-derived hydrogen peroxide (H2O2) is an EDHF that is produced in part by endothelial NO synthase (eNOS). In this study, we show that genetic disruption of all three NOS isoforms (neuronal [nNOS], inducible [iNOS], and endothelial [eNOS]) abolishes EDHF responses in mice. The contribution of the NOS system to EDHF-mediated responses was examined in eNOS−/−, n/eNOS−/−, and n/i/eNOS−/− mice. EDHF-mediated relaxation and hyperpolarization in response to acetylcholine of mesenteric arteries were progressively reduced as the number of disrupted NOS genes increased, whereas vascular smooth muscle function was preserved. Loss of eNOS expression alone was compensated for by other NOS genes, and endothelial cell production of H2O2 and EDHF-mediated responses were completely absent in n/i/eNOS−/− mice, even after antihypertensive treatment with hydralazine. NOS uncoupling was not involved, as modulation of tetrahydrobiopterin (BH4) synthesis had no effect on EDHF-mediated relaxation, and the BH4/dihydrobiopterin (BH2) ratio was comparable in mesenteric arteries and the aorta. These results provide the first evidence that EDHF-mediated responses are dependent on the NOSs system in mouse mesenteric arteries

    Factors associated with employment in patients undergoing hemodialysis: a mixed methods study

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    Abstract Background For patients undergoing hemodialysis, continuing in labor is very challenging and many patients have difficulty in current and/or previous workplaces. The objective of the present study is to clarify the determinants of being employed in hemodialysis patients by use of the mixed methods approach. Methods One hundred and forty-nine patients undergoing hemodialysis were interviewed between 2010 and 2011 using the “100-category checklists” based on the International Classification of Functioning, Disability and Health developed for hemodialysis patients. The categories with which the participants experienced difficulty at workplace were analyzed using the mixed methods approach. In quantitative data, the patients undergoing hemodialysis were divided into two groups if they experienced any difficulty in current and/or previous workplaces (i.e., “experienced” group vs. “not experienced” group). In qualitative data, responses to the open-ended questions were analyzed using a grounded theory approach. Results In total of 149 patients (male, 66%; mean age 62 years; mean hemodialysis vintage, 8.6 years), 62% had diabetes and 86% were in labor at the time of investigation. In a quantitative analysis, compared to the unexperienced group, the experienced group was more likely to show the physical problems such as fatigability and decline of physical strength and declined energy level. In a qualitative analysis, three determinants of being unemployed were emerged including hospital visits (i.e., three times a week), vascular access, and physical symptoms. In contrast, a favorable determinant for the work continuation and job opportunities was found to be a flexible dialysis shift. Conclusions Our mixed methods study suggests that patients undergoing hemodialysis frequently suffer from physical problems such as frequent hospital visits for hemodialysis, vascular access troubles, and physical distress, resulting in frequent unemployment. One solution for unemployment of the patients undergoing hemodialysis is a dialysis shift flexible for individual lifestyles

    Stereotactic body radiation therapy for clinically diagnosed early‐stage non‐small cell lung cancer: Importance of accurate CT interpretation by experts

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    Abstract Introduction This study evaluated the clinical outcomes of stereotactic body radiotherapy (SBRT) for both pathologically diagnosed (PD) and clinically diagnosed (CD) early‐stage non‐small cell lung cancer (NSCLC) and explored the significance of accurate expert computed tomography (CT) interpretation. Methods We retrospectively analyzed 95 patients with early‐stage NSCLC who received SBRT at our institution. Patients were classified into CD and PD groups. Two chest radiologists retrospectively interpreted the pre‐SBRT CT images to determine the tumor subtype and probability of malignancy (PM). Clinical findings, CT features, and treatment outcomes were compared between the two groups. The survival rate of the CD group was analyzed separately according to the PM grade. Results Median overall survival for the CD and PD groups was 6.0 and 5.4 years (P = 0.57), respectively. Median cause‐specific survival was 10.2 years in the CD group and not reached in the PD group (P = 0.76). In the CD group, lung cancer mortality was lower in the low PM group (25% [1 of 4]) than in the high PM group (47.4% [9 of 19]). Conclusion It may be desirable to evaluate the PM of the nodule using expert CT interpretation to decide whether SBRT is indicated in CD early‐stage NSCLC

    Fundamental Characterization of Antibody Fusion-Single-Chain TNF Recombinant Proteins Directed against Costimulatory TNF Receptors Expressed by T-Lymphocytes

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    The costimulatory signal regulated by the members of the tumor necrosis factor receptor (TNFR) superfamily expressed by T cells plays essential roles for T cell responses and has emerged as a promising target for cancer immunotherapy. However, it is unclear how the difference in TNFR costimulation contributes to T cell responses. In this study, to clarify the functional significance of four different TNFRs, OX40, 4-1BB, CD27 and GITR, we prepared corresponding single-chain TNF ligand proteins (scTNFLs) connected to IgG Fc domain with beneficial characteristics, i.e., Fc−scOX40L, Fc−sc4-1BBL, Fc−scCD27L (CD70) and Fc−scGITRL. Without intentional cross-linking, these soluble Fc−scTNFL proteins bound to corresponding TNFRs induced NF-kB signaling and promoted proliferative and cytokine responses in CD4+ and CD8+ T cells with different dose-dependencies in vitro. Mice injected with one of the Fc−scTNFL proteins displayed significantly augmented delayed-type hypersensitivity responses, showing in vivo activity. The results demonstrate that each individual Fc−scTNFL protein provides a critical costimulatory signal and exhibits quantitatively distinct activity toward T cells. Our findings provide important insights into the TNFR costimulation that would be valuable for investigators conducting basic research in cancer immunology and also have implications for T cell-mediated immune regulation by designer TNFL proteins

    Transcriptional Elongation Factor Elongin A Regulates Retinoic Acid-Induced Gene Expression during Neuronal Differentiation

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    SummaryElongin A increases the rate of RNA polymerase II (pol II) transcript elongation by suppressing transient pausing by the enzyme. Elongin A also acts as a component of a cullin-RING ligase that can target stalled pol II for ubiquitylation and proteasome-dependent degradation. It is not known whether these activities of Elongin A are functionally interdependent in vivo. Here, we demonstrate that Elongin A-deficient (Elongin A−/−) embryos exhibit abnormalities in the formation of both cranial and spinal nerves and that Elongin A−/− embryonic stem cells (ESCs) show a markedly decreased capacity to differentiate into neurons. Moreover, we identify Elongin A mutations that selectively inactivate one or the other of the aforementioned activities and show that mutants that retain the elongation stimulatory, but not pol II ubiquitylation, activity of Elongin A rescue neuronal differentiation and support retinoic acid-induced upregulation of a subset of neurogenesis-related genes in Elongin A−/− ESCs
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