163 research outputs found

    Physiological and Pathological Mitochondrial Clearance Is Related to Pectoralis Major Muscle Pathogenesis in Broilers With Wooden Breast Syndrome

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    Wooden breast syndrome (WB) constitutes an emerging myopathy in the pectoralis major muscle (PM) of broiler chickens, characterized by myofiber hypertrophy and degeneration along with severe fibrosis. WB pathogenesis has been considered to involve hypoxia induced by rapid growth of the PM. In this study, we focused on mitochondrial morphology and dynamics in the myofibers, as these organelles are sensitive to damage by hypoxia, and examined the effects on WB pathogenesis. Specifically, the PMs of a flock of 35 broilers at 50 days of age were evaluated. First, the severity of disease in each bird was determined by measuring histopathological indices including the fibrotic area (FA) in the muscle and circularity of myofibers (CM). These values were 29.4 ± 9.6% and 0.70 ± 0.042, respectively, showing variety among the flock. Myofiber vacuolization was observed in all birds including numerous small- or large-rimmed vacuoles, with the former consisting of ultrastructurally autophagosome-like vacuoles engulfing degenerated mitochondria. The large-rimmed vacuoles frequently occurred in the PMs with more severe FA and CM, indicating a relationship between altered autophagy/mitophagy and WB severity. Next, the expression levels of hypoxia-adaptive and mitochondrial dynamics-related genes were analyzed, and their correlations with the histopathological indices were examined. The histopathological indices were negatively correlated with the expression of vascular endothelial growth factor A (VEGFA), indicating that less angiogenesis owing to weakened hypoxia-inducible factor signaling induces more severe WB pathology. In addition, the observed negative correlation with mitochondrial dynamics-related genes implied that WB pathology deteriorates concomitant with reduced mitochondrial dynamics. Furthermore, the expression of mitochondrial dynamics-related genes showed strong positive correlation with that of VEGFA and autophagy-/mitophagy-related genes. These results revealed that the PMs of broilers possess the mechanism of physiological clearance of mitochondria damaged by the hypoxia resulting from the continuous mitochondrial dynamics and autophagy/mitophagy accompanying rapid PM growth. In turn, the altered mitochondrial clearance induced by chronic hypoxia and the accumulation of damaged mitochondria likely underly the severe pathological features of WB.ArticleFrontiers in Pharmacology.11:579(2020)journal articl

    Anomalous Transport Properties in BiS2-based Superconductors LnO1−xFxBiS2 (Ln = Nd, La-Sm)

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    We report the electronic properties of the layered bismuth-based sulfide superconductors NdO1−xFxBiS2 (x = 0.25, 0.4, and 0.5) and La1−ySmyO0.5F0.5BiS2 (y = 0.1–0.7), which have been studied by investigation of their transport properties and X-ray diffraction. In the lightly carrier-doped NdO1−xFxBiS2 (x = 0.25 and 0.4) and La1−ySmyO0.5F0.5BiS2 (y = 0.3 and 0.4), the resistivity and Hall coefficient exhibit anomalous temperature dependences below TCDW ∼ 130 and 200 K, respectively, suggesting the formation of an energy gap on the Fermi surface associated with charge-density wave (CDW). In NdO1−xFxBiS2 (x = 0.25), the bond angles and bond lengths of the Bi–S pentahedron change their temperature dependences below ∼200 K, suggesting that a lattice instability related to the Bi–S pentahedron exists below ∼200 K, which is much higher than TCDW. These results indicate that the lattice instability of the Bi–S pentahedron can trigger a CDW transition in the low-carrier region of BiS2 superconductors

    Stress relaxation arrested the mainshock rupture of the 2016 Central Tottori earthquake

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    地震の破壊はなぜ止まるのか? --2016年鳥取県中部地震の断層サイズを決めたもの--. 京都大学プレスリリース. 2021-08-12.After a large earthquake, many small earthquakes, called aftershocks, ensue. Additional large earthquakes typically do not occur, despite the fact that the large static stress near the edges of the fault is expected to trigger further large earthquakes at these locations. Here we analyse ~10, 000 highly accurate focal mechanism solutions of aftershocks of the 2016 Mw 6.2 Central Tottori earthquake in Japan. We determine the location of the horizontal edges of the mainshock fault relative to the aftershock hypocentres, with an accuracy of approximately 200 m. We find that aftershocks rarely occur near the horizontal edges and extensions of the fault. We propose that the mainshock rupture was arrested within areas characterised by substantial stress relaxation prior to the main earthquake. This stress relaxation along fault edges could explain why mainshocks are rarely followed by further large earthquakes

    分子系統地理学に生態ニッチモデリングがもたらす新展開と課題

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    Understanding species distribution patterns is a long-standing challenge in biodiversity assessments and spatiotemporal shifts in these patterns has recently been the focus of many studies within the fields of palaeoecology and phylogeography. Due to recent advances in ecological niche models (ENM), it is now possible to reconstruct past species distributions, thus ENM combined with genetic-based inference has the potential to provide new insights in phylogeography, which were not possible using traditional approaches, by taking into account the spatiotemporal dynamics of distribution ranges, niche shifts, demographic events, and local adaptations. In this review paper, we give overviews of several topics, including: 1) the introduction of recent advances in ENM, as well as the problems associated with traditional approaches of reconstructing past species distributions in palaeoecology; 2) niche shifts along temporal scales; 3) the inference of past demographic history based on genetic data and ENM; and 4) the estimation of the distribution of genetic variation in relation to local adaptation. Although we have reached a new stage of phylogeography incorporating ENM, some limitations remain. Thus, we discuss how to apply the current tools to advance the study and application of phylogeography, as well as the need for further development within the field

    Effect of Daily Glucose Fluctuation on Coronary Plaque Vulnerability in Patients Pre-Treated With Lipid-Lowering Therapy A Prospective Observational Study

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    AbstractObjectivesThis study sought to investigate the effect of daily glucose fluctuation on coronary plaque properties in patients with coronary artery disease (CAD) pre-treated with lipid-lowering therapy.BackgroundThere is growing evidence that glucose fluctuation, as a residual risk apart from dyslipidemia, is an important factor contributing to the development of CAD.MethodsThis prospective study enrolled 70 consecutive CAD patients who were referred for percutaneous coronary intervention and whose low-density lipoprotein cholesterol level was <120 mg/dl under statin treatment or <100 mg/dl without statins. Daily glucose fluctuation was analyzed by measuring the mean amplitude of glycemic excursion (MAGE). The plaque properties in the culprit and nonculprit lesions were assessed by virtual histology intravascular ultrasound, and the volume percentage of necrotic core within the plaque (%NC) and the presence of thin-cap fibroatheroma were evaluated.ResultsIn total, 165 lesions were evaluated in 70 patients (40 diabetic and 30 nondiabetic patients). %NC was well correlated with MAGE (r = 0.490, p <0.001). A linear mixed effect model showed that MAGE had the strongest effect on %NC (coefficient β = 0.080 ± 0.020 [standard error], p < 0.001). The generalized linear mixed effect model revealed that MAGE was the only independent predictor of the presence of thin-cap fibroatheroma (odds ratio: 1.037; 95% confidence interval: 1.010 to 1.065; p = 0.007).ConclusionsDaily glucose fluctuation may have an effect on coronary plaque vulnerability in patients with CAD pre-treated with lipid-lowering therapy. Further investigations should address the rationale for the early detection and control of glucose fluctuation in the era of universal statin use for CAD patients

    Removal of a catheter mount and heat-and-moisture exchanger improves hypercapnia in patients with acute respiratory distress syndrome

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    To avoid ventilator-associated lung injury in acute respiratory distress syndrome (ARDS) treatment, respiratory management should be performed at a low tidal volume of 6 to 8 mL/kg and plateau pressure of ≤30 cmH2O. However, such lung-protective ventilation often results in hypercapnia, which is a risk factor for poor outcomes. The purpose of this study was to retrospectively evaluate the effectiveness and safety of the removal of a catheter mount (CM) and using heated humidifiers (HH) instead of a heat-and-moisture exchanger (HME) for reducing the mechanical dead space created by the CM and HME, which may improve hypercapnia in patients with ARDS.This retrospective observational study included adult patients with ARDS, who developed hypercapnia (PaCO2 > 45 mm Hg) during mechanical ventilation, with target tidal volumes between 6 and 8 mL/kg and a plateau pressure of ≤30 cmH2O, and underwent stepwise removal of CM and HME (replaced with HH). The PaCO2 values were measured at 3 points: ventilator circuit with CM and HME (CM + HME) use, with HME (HME), and with HH (HH), and the overall number of accidental extubations was evaluated. Ventilator values (tidal volume, respiratory rate, minutes volume) were evaluated at the same points.A total of 21 patients with mild-to-moderate ARDS who were treated under deep sedation were included. The values of PaCO2 at HME (52.7 ± 7.4 mm Hg, P < .0001) and HH (46.3 ± 6.8 mm Hg, P < .0001) were significantly lower than those at CM + HME (55.9 ± 7.9 mm Hg). Measured ventilator values were similar at CM + HME, HME, and HH. There were no cases of reintubation due to accidental extubation after the removal of CM.The removal of CM and HME reduced PaCO2 values without changing the ventilator settings in deeply sedated patients with mild-to-moderate ARDS on lung-protective ventilation. Caution should be exercised, as the removal of a CM may result in circuit disconnection or accidental extubation. Nevertheless, this intervention may improve hypercapnia and promote lung-protective ventilation

    首都圏・近畿圏における大都市圏地殻構造調査

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    Deep seismic profiling was performed in the Kanto and Kinki areas to obtain a better estimation of strong ground motions. In the Kanto area, we identify the seismogenic source fault on the upper surface of the Philippine Sea plate. The depth to the top of this plate, 4 to 26 km, is much shallower than previously estimated from the distribution of seismicity. This shallower plate geometry changes the location of the maximum finite slip of the 1923 Kanto earthquake, and its location corresponds to a zone of poor reflection on the mega-thrust, namely, a strong reflectivity zone along the mega-thrust coincidences with aseismic slip zone. In the Kinki area, 120-km-long seismic reflection profiling was carried out from Osaka to Suzuka across the Osaka and Ise basins and several active faults. Deep sub-horizontal reflectors are found at 26 and 16km in depth. The shallower re flectors correspond to the base of the seismogenic zone. Dipping reflectors, probably deeper extensions of active faults, merge into the mid-crustal reflectors
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