224 research outputs found

    Sensitive determination of total particulate phosphorus and particulate inorganic phosphorus in seawater using liquid waveguide spectrophotometry

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    Determining the total particulate phosphorus (TPP) and particulate inorganic phosphorus (PIP) in oligotrophic oceanic water generally requires the filtration of a large amount of water sample. This paper describes methods that require small filtration volumes for determining the TPP and PIP concentrations. The methods were devised by validating or improving conventional sample processing and by applying highly sensitive liquid waveguide spectrophotometry to the measurements of oxidized or acid-extracted phosphate from TPP and PIP, respectively. The oxidation of TPP was performed by a chemical wet oxidation method using 3% potassium persulfate. The acid extraction of PIP was initially carried out based on the conventional extraction methodology, which requires 1 M HCl, followed by the procedure for decreasing acidity. While the conventional procedure for acid removal requires a ten-fold dilution of the 1 M HCl extract with purified water, the improved procedure proposed in this study uses 8 M NaOH solution for neutralizing 1 M HCl extract in order to reduce the dilution effect. An experiment for comparing the absorbances of the phosphate standard dissolved in 0.1 M HCl and of that dissolved in a neutralized solution [1 M HCl : 8 M NaOH = 8:1 (v:v)] exhibited a higher absorbance in the neutralized solution. This indicated that the improved procedure completely removed the acid effect, which reduces the sensitivity of the phosphate measurement. Application to an ultraoligotrophic water sample showed that the TPP concentration in a 1075 mL-filtered sample was 8.4 nM with a coefficient of variation (CV) of 4.3% and the PIP concentration in a 2300 mL-filtered sample was 1.3 nM with a CV of 6.1%. Based on the detection limit (3 nM) of the sensitive phosphate measurement and the ambient TPP and PIP concentrations of the ultraoligotrophic water, the minimum filtration volumes required for the detection of TPP and PIP were estimated to be 15 and 52 mL, respectively

    Transforming growth factor α protects against Fas-mediated liver apoptosis in mice

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    AbstractThe Fas/Fas ligand interaction plays a crucial role in various liver diseases, and administration of agonistic anti-Fas antibody to mice causes massive hepatic apoptosis and fulminant hepatic failure. Several growth factors have recently been found to function in preventing apoptosis. In this study, we demonstrated that overexpression of transforming growth factor α (TGFα) has a dramatic protective effect on Fas-mediated hepatic apoptosis at the biochemical and histological levels. Moreover, 85.7% (six out of seven) of TGFα transgenic mice survived the lethal liver damage, whereas all wild-type mice died. Expression of Bcl-xL, an anti-apoptotic protein, was greatly increased in the transgenic mice. Taken together, our findings suggest that TGFα protects against Fas-mediated liver apoptosis in vivo and up-regulation of Bcl-xL may participate in protective effect of TGFα

    Characterization of genetically modified mice for phosphoglycerate mutase, a vitally-essential enzyme in glycolysis

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    Models de ratolí; Glucòlisi; Diabetis mellitusModelos de ratón; Glucólisis; Diabetes mellitusMouse models; Glycolysis; Diabetes mellitusGlycolytic metabolism is closely involved in physiological homeostasis and pathophysiological states. Among glycolytic enzymes, phosphoglycerate mutase (PGAM) has been reported to exert certain physiological role in vitro, whereas its impact on glucose metabolism in vivo remains unclear. Here, we report the characterization of Pgam1 knockout mice. We observed that homozygous knockout mice of Pgam1 were embryonic lethal. Although we previously reported that both PGAM-1 and -2 affect global glycolytic profile of cancers in vitro, in vivo glucose parameters were less affected both in the heterozygous knockout of Pgam1 and in Pgam2 transgenic mice. Thus, the impact of PGAM on in vivo glucose metabolism is rather complex than expected before.This work was supported in part by grants from the Japan Society for the Promotion of Science (Grants No. 26310103 to HK and No. 15K19283 to HK), and by the Japan Agency for Medical Research and Development (AMED), Core Research for Evolutional Science and Technology (CREST JP17gm0610002h0306 to HK). HK; Hiroshi Kondoh

    Image-based evaluation of contraction–relaxation kinetics of human-induced pluripotent stem cell-derived cardiomyocytes: Correlation and complementarity with extracellular electrophysiology

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    AbstractIn this study, we used high-speed video microscopy with motion vector analysis to investigate the contractile characteristics of hiPS-CM monolayer, in addition to further characterizing the motion with extracellular field potential (FP), traction force and the Ca2+ transient. Results of our traction force microscopy demonstrated that the force development of hiPS-CMs correlated well with the cellular deformation detected by the video microscopy with motion vector analysis. In the presence of verapamil and isoproterenol, contractile motion of hiPS-CMs showed alteration in accordance with the changes in fluorescence peak of the Ca2+ transient, i.e., upstroke, decay, amplitude and full-width at half-maximum. Simultaneously recorded hiPS-CM motion and FP showed that there was a linear correlation between changes in the motion and field potential duration in response to verapamil (30–150nM), isoproterenol (0.1–10μM) and E-4031 (10–50nM). In addition, tetrodotoxin (3–30μM)-induced delay of sodium current was corresponded with the delay of the contraction onset of hiPS-CMs. These results indicate that the electrophysiological and functional behaviors of hiPS-CMs are quantitatively reflected in the contractile motion detected by this image-based technique. In the presence of 100nM E-4031, the occurrence of early after-depolarization-like negative deflection in FP was also detected in the hiPS-CM motion as a characteristic two-step relaxation pattern. These findings offer insights into the interpretation of the motion kinetics of the hiPS-CMs, and are relevant for understanding electrical and mechanical relationship in hiPS-CMs

    ダパグリフロジン投与における肥満2型糖尿病患者の治療満足度への影響:a patient reported outcome study (PRO study).

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    Background: The benefits of sodium glucose cotransporters 2 (SGLT2) inhibitors in patients with type 2 diabetes mellitus include plasma glucose control, reduction in body weight and blood pressure, and low risk of hypoglycemia, although they may also cause genitourinary infections, polyuria, or volume depletion. It is not clear whether dapagliflozin, an SGLT2 inhibitor, improves treatment satisfaction among patients in a comprehensive way despite the negative side effects. This study assessed the effect of dapagliflozin on glycosylated hemoglobin (HbA1c), body weight, and treatment satisfaction in overweight patients with type 2 diabetes mellitus treated with oral hypoglycemic agents. Methods: This multicenter, open-label, single-arm observational study included patients with type 2 diabetes mellitus administering dapagliflozin 5 or 10 mg per day for 14 weeks. Changes in treatment satisfaction were evaluated using a new version of the Oral Hypoglycemic Agent-Questionnaire (OHA-Q ver. 2) consisting of 23 items. Correlation between treatment satisfaction and HbA1c levels and body weight were analyzed using the Spearman's rank-correlation coefficient. Results: Of the 221 patients enrolled, 188 completed the study. Mean HbA1c decreased from 7.8 ± 0.7% (62.1 ± 7.5 mmol/mol) to 7.3 ± 0.8% (55.9 ± 8.7 mmol/mol) (change - 0.6 ± 0.7%, P < 0.001) and body weight decreased from 82.5 ± 14.6 to 80.7 ± 14.8 kg (change - 2.3 ± 2.8 kg, P < 0.001). OHA-Q ver. 2 was validated as well, the mean OHA-Q ver. 2 total score increased from 44.3 ± 9.4 to 46.6 ± 9.8 (best score 69, worst score 0; change 2.3 ± 6.6, P < 0.001). The change in body weight significantly correlated with the OHA-Q ver. 2 total score (Spearman's ρ = - 0.17, P = 0.035). The change in HbA1c levels significantly correlated with the satisfaction subscale score (Spearman's ρ = - 0.19, P = 0.011). Conclusions: Dapagliflozin significantly improved treatment satisfaction among patients with type 2 diabetes mellitus for 14 weeks. Body weight loss significantly correlated with treatment satisfaction.Trial registration UMIN-CTR: UMIN000016304.博士(医学)・甲第694号・平成31年3月15日© The Author(s) 2018. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated

    A new species of Xenoturbella from the western Pacific Ocean and the evolution of Xenoturbella

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    BackgroundXenoturbella is a group of marine benthic animals lacking an anus and a centralized nervous system. Molecular phylogenetic analyses group the animal together with the Acoelomorpha, forming the Xenacoelomorpha. This group has been suggested to be either a sister group to the Nephrozoa or a deuterostome, and therefore it may provide important insights into origins of bilaterian traits such as an anus, the nephron, feeding larvae and centralized nervous systems. However, only five Xenoturbella species have been reported and the evolutionary history of xenoturbellids and Xenacoelomorpha remains obscure.ResultsHere we describe a new Xenoturbella species from the western Pacific Ocean, and report a new xenoturbellid structure - the frontal pore. Non-destructive microCT was used to investigate the internal morphology of this soft-bodied animal. This revealed the presence of a frontal pore that is continuous with the ventral glandular network and which exhibits similarities with the frontal organ in acoelomorphs.ConclusionsOur results suggest that large size, oval mouth, frontal pore and ventral glandular network may be ancestral features for Xenoturbella. Further studies will clarify the evolutionary relationship of the frontal pore and ventral glandular network of xenoturbellids and the acoelomorph frontal organ. One of the habitats of the newly identified species is easily accessible from a marine station and so this species promises to be valuable for research on bilaterian and deuterostome evolution

    A single amino acid mutation in an ABC transporter gene causes resistance to Bt toxin Cry1Ab in the silkworm, \u3cem\u3eBombyx mori\u3c/em\u3e

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    Bt toxins derived from the arthropod bacterial pathogen Bacillus thuringiensis are widely used for insect control as insecticides or in transgenic crops. Bt resistance has been found in field populations of several lepidopteran pests and in laboratory strains selected with Bt toxin. Widespread planting of crops expressing Bt toxins has raised concerns about the potential increase of resistance mutations in targeted insects. By using Bombyx mori as a model, we identified a candidate gene for a recessive form of resistance to Cry1Ab toxin on chromosome 15 by positional cloning. BGIBMGA007792-93, which encodes an ATP-binding cassette transporter similar to human multidrug resistance protein 4 and orthologous to genes associated with recessive resistance to Cry1Ac in Heliothis virescens and two other lepidopteran species, was expressed in the midgut. Sequences of 10 susceptible and seven resistant silkworm strains revealed a common tyrosine insertion in an outer loop of the predicted transmembrane structure of resistant alleles. We confirmed the role of this ATP-binding cassette transporter gene in Bt resistance by converting a resistant silkworm strain into a susceptible one by using germline transformation. This study represents a direct demonstration of Bt resistance gene function in insects with the use of transgenesis

    Autopsy of a patient with restrictive cardiomyopathy with and MYH7 mutation

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    Restrictive cardiomyopathy (RCM) is a rare type of primary myocardial disease, and its pathological features remain unclear. We report the case of a 78-year-old Japanese woman with RCM and MHY7 mutation who died of heart failure 13 years after the diagnosis. Upon autopsy, focal myocyte amorphous degeneration positive for ubiquitin was revealed, as well as myocardial disarrangement and interstitial fibrosis. Electron microscope demonstrated electron-dense structure in the cardiac myocytes. These may be one of the pathological features of RCM
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