121 research outputs found

    Taurine Depletion-Related Cardiomyopathy in Animals

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    Probabilistic cloning with supplementary information

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    We consider probabilistic cloning of a state chosen from a mutually nonorthogonal set of pure states, with the help of a party holding supplementary information in the form of pure states. When the number of states is 2, we show that the best efficiency of producing m copies is always achieved by a two-step protocol in which the helping party first attempts to produce m-1 copies from the supplementary state, and if it fails, then the original state is used to produce m copies. On the other hand, when the number of states exceeds two, the best efficiency is not always achieved by such a protocol. We give examples in which the best efficiency is not achieved even if we allow any amount of one-way classical communication from the helping party.Comment: 6 pages, no figure

    The potential usefulness of taurine on diabetes mellitus and its complications

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    Taurine (2-aminoethanesulfonic acid) is a free amino acid found ubiquitously in millimolar concentrations in all mammalian tissues. Taurine exerts a variety of biological actions, including antioxidation, modulation of ion movement, osmoregulation, modulation of neurotransmitters, and conjugation of bile acids, which may maintain physiological homeostasis. Recently, data is accumulating that show the effectiveness of taurine against diabetes mellitus, insulin resistance and its complications, including retinopathy, nephropathy, neuropathy, atherosclerosis and cardiomyopathy, independent of hypoglycemic effect in several animal models. The useful effects appear due to the multiple actions of taurine on cellular functions. This review summarizes the beneficial effects of taurine supplementation on diabetes mellitus and the molecular mechanisms underlying its effectiveness

    大学授業における教員のメディア利用と授業評価の関係

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    本研究では,大学授業における教員のメディア利用と,学生の授業評価の関係を調査することを目的とした.まず,ある私立大学の教員(67名)に,授業において使用しているメディアをたずねるアンケート調査を実施した.そして,アンケートの回答を行った教員が担当する授業で,学生に授業評価アンケートを実施することにより,教員のメディア利用と授業評価の相関分析を行った.その結果,教員の授業におけるメディア利用と学生による授業評価には,直接的な関係性が見られないことが明らかになった.この結果から,メディア利用の効果を検証するためには,授業の場面や目的に応じた適切なメディア利用の調査が必要であることが示唆された

    Physiological roles of taurine in heart and muscle

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    Taurine (aminoethane sulfonic acid) is an ubiquitous compound, found in very high concentrations in heart and muscle. Although taurine is classified as an amino acid, it does not participate in peptide bond formation. Nonetheless, the amino group of taurine is involved in a number of important conjugation reactions as well as in the scavenging of hypochlorous acid. Because taurine is a fairly inert compound, it is an ideal modulator of basic processes, such as osmotic pressure, cation homeostasis, enzyme activity, receptor regulation, cell development and cell signalling. The present review discusses several physiological functions of taurine. First, the observation that taurine depletion leads to the development of a cardiomyopathy indicates a role for taurine in the maintenance of normal contractile function. Evidence is provided that this function of taurine is mediated by changes in the activity of key Ca2+ transporters and the modulation Ca2+ sensitivity of the myofibrils. Second, in some species, taurine is an established osmoregulator, however, in mammalian heart the osmoregulatory function of taurine has recently been questioned. Third, taurine functions as an indirect regulator of oxidative stress. Although this action of taurine has been widely discussed, its mechanism of action is unclear. A potential mechanism for the antioxidant activity of taurine is discussed. Fourth, taurine stabilizes membranes through direct interactions with phospholipids. However, its inhibition of the enzyme, phospholipid N-methyltransferase, alters the phosphatidylcholine and phosphatidylethanolamine content of membranes, which in turn affects the function of key proteins within the membrane. Finally, taurine serves as a modulator of protein kinases and phosphatases within the cardiomyocyte. The mechanism of this action has not been studied. Taurine is a chemically simple compound, but it has profound effects on cells. This has led to the suggestion that taurine is an essential or semi-essential nutrient for many mammals

    Effect of β-alanine treatment on mitochondrial taurine level and 5-taurinomethyluridine content

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    <p>Abstract</p> <p>Background</p> <p>The β-amino acid, taurine, is a nutritional requirement in some species. In these species, the depletion of intracellular stores of taurine leads to the development of severe organ dysfunction. The basis underlying these defects is poorly understood, although there is some suggestion that oxidative stress may contribute to the abnormalities. Recent studies indicate that taurine is required for normal mitochondrial protein synthesis and normal electron transport chain activity; it is known that defects in these events can lead to severe mitochondrial oxidative stress. The present study examines the effect of taurine deficiency on the first step of mitochondrial protein synthesis regulation by taurine, namely, the formation of taurinomethyluridine containing tRNA.</p> <p>Methods</p> <p>Isolated rat cardiomyocytes were rendered taurine deficient by incubation with medium containing the taurine transport inhibitor, β-alanine. The time course of cellular and mitochondrial taurine depletion was measured. The primer extension method was employed to evaluate the effect of β-alanine treatment on taurinomethyluridine content of tRNA<sup>Leu</sup>. The protein levels of ND6 were also determined by Western blot analysis.</p> <p>Results</p> <p>β-alanine caused a time-dependent decrease in cellular taurine content, which were reduced in half after 48 hrs of incubation. The amount of taurine in the mitochondria was considerably less than that in the cytosol and was unaffected by β-alanine treatment. Approximately 70% of the tRNA<sup>Leu</sup> in the untreated cell lacked taurinomethyluridine and these levels were unchanged following β-alanine treatment. Protein content of ND6, however, was significantly reduced after 48 hours incubation with β-alanine.</p> <p>Conclusions</p> <p>The taurine levels of the cytosol and the mitochondria are not directly coupled. The β-alanine-mediated reduction in taurine levels is too small to affect taurinomethyluridine levels. Nonetheless, it interferes with mitochondrial protein synthesis, as exemplified by a decrease in ND6 protein content. Thus, β-alanine does not cause alterations in mitochondrial protein synthesis through the lowering of taurine levels.</p

    Study of active controlled tocilizumab monotherapy for rheumatoid arthritis patients with an inadequate response to methotrexate (SATORI): significant reduction in disease activity and serum vascular endothelial growth factor by IL-6 receptor inhibition therapy

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    We investigated the clinical efficacy and safety of tocilizumab (a humanized anti-IL-6 receptor antibody) monotherapy in active rheumatoid arthritis (RA) patients with an inadequate response to low dose methotrexate (MTX). In a multicenter, double-blind, randomized, controlled trial, 125 patients were allocated to receive either tocilizumab 8 mg/kg every 4 weeks plus MTX placebo (tocilizumab group) or tocilizumab placebo plus MTX 8 mg/week (control group) for 24 weeks. The clinical responses were measured using the American College of Rheumatology (ACR) criteria and the Disease Activity Score in 28 joints. Serum vascular endothelial growth factor (VEGF) levels were also monitored. At week 24, 25.0% in the control group and 80.3% in the tocilizumab group achieved ACR20 response. The tocilizumab group showed superior ACR response criteria over control at all time points. Additionally, serum VEGF levels were significantly decreased by tocilizumab treatment. The overall incidences of adverse events (AEs) were 72 and 92% (serious AEs: 4.7 and 6.6%; serious infections: 1.6 and 3.3%) in the control and the tocilizumab groups, respectively. All serious adverse events improved by adequate treatment. Tocilizumab monotherapy was well tolerated and provided an excellent clinical benefit in active RA patients with an inadequate response to low dose MTX

    Cardiac and skeletal muscle abnormality in taurine transporter-knockout mice

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    Taurine, a sulfur-containing β-amino acid, is highly contained in heart and skeletal muscle. Taurine has a variety of biological actions, such as ion movement, calcium handling and cytoprotection in the cardiac and skeletal muscles. Meanwhile, taurine deficiency leads various pathologies, including dilated cardiomyopathy, in cat and fox. However, the essential role of taurine depletion on pathogenesis has not been fully clarified. To address the physiological role of taurine in mammalian tissues, taurine transporter-(TauT-) knockout models were recently generated. TauTKO mice exhibited loss of body weight, abnormal cardiac function and the reduced exercise capacity with tissue taurine depletion. In this chapter, we summarize pathological profile and histological feature of heart and skeletal muscle in TauTKO mice

    PLAG1 enhances the stemness profiles of acinar cells in normal human salivary glands in a cell type-specific manner

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    Objectives: Details of the histogenesis of salivary gland tumors are largely unknown. The oncogenic role of PLAG1 in the salivary gland has been demonstrated in vivo. Herein, we demonstrate the roles of PLAG1 in the acinar and ductal cells of normal human salivary glands in an attempt to clarify the early events that occur during the histogenesis of salivary gland tumors. Methods: Normal salivary gland cells with acinar- (NS-SV-AC) and ductal- (NS-SV-DC) phenotypes were transfected with PLAG1 plasmid DNA. Subsequently, the PLAG1 overexpressed and mock cells were examined by cell proliferation, transwell migration, and salisphere formation assays. The expression levels of salivary and pluripotent stem cell markers and differentiation markers were evaluated by quantitative real-time polymerase chain reaction and immunofluorescence. Alterations in transcriptional expressions were investigated via cap analysis of gene expression with gene-enrichment and functional annotation analysis. Results: PLAG1 promoted cell proliferation and transwell migration in the acinar and ductal cells, and markedly enhanced the stemness profiles and luminal cell-like profiles in acinar cells; the stemness profiles were partially increased in the ductal cells. Conclusion: PLAG1 enhanced the stemness profiles in the acinar cells of normal human salivary glands in a cell type-specific manner. Thus, it may be involved in salivary gland tumorigenesis by increasing the stemness character of the normal salivary gland cells

    Association of paraoxonase 1 gene polymorphism with Intima-Media Thickness (IMT) of the carotid arteries in japanese type 2 diabetic patients

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    Purpose: We investigated the association between paraoxonase 1 (PON1)-192 genotypes and intimamedia thickness (IMT) of carotid arteries in diabetic patients. Methods: One hundred and fifty-five Japanese type 2 diabetic patients aged from 40 to 79 years were enrolled in this study. Genotypes of the patients were determined using the PCR-RFLP method. The IMT of carotid arteries of the subjects was measured by ultrasound imaging. Results: The PON1 genotypes frequencies were as follows: 18QQ (0.116), 70QR (0.452) and 67RR (0.432). IMT values of the RR group were significantly greater (1.08±0.41 mm, n=67) than those of the Q group, which consisted of patients carrying one or two Q alleles (0.95±0.27 mm, n=88, P=0.023). There were no significant difference in the clinical characteristics between the two groups. Conclusion: The results indicate that the PON1-192RR genotype is associated with intima media thickening of the carotid arteries in diabetic patients
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