488 research outputs found

    Ziram, a dithiocarbamate fungicide, exhibits pseudo-cytoprotective actions against oxidative stress in rat thymocytes : Possible environmental risks

    Get PDF
    Ziram, a dithiocarbamate fungicide, protects various vegetables and fruits against infections by fungus. Recently, there have been increasing anxieties about the risks in the use of dithiocarbamate fungicides. Our previous studies showed that Zn2+ was a determinant of Ziram cytotoxicity. In addition, Zn2+ is linked to H2O2 cytotoxicity. Therefore, in this study, we aimed to test the hypothesis that Ziram could augment the cytotoxicity of H2O2 by examining the changes induced by Ziram in some cellular parameters in rat thymic lymphocytes subjected to H2O2-induced oxidative stress using flow-cytometric methods with fluorescent dyes. Ziram significantly attenuated H2O2-induced cell death at sublethal concentrations. However, in the cells under oxidative stress elicited by H2O2, Ziram promoted the changing over from intact cells to living cells with exposed phosphatidylserine (PS) on plasma membranes, whereas it inhibited the transition from PS-exposed living cells to dead cells. Ziram significantly augmented H2O2 actions, including reduction of cellular glutathione levels and elevation of intracellular Zn2+ concentrations. Conversely, it attenuated H2O2-induced depolarization of mitochondrial membrane potential. Ziram at sublethal concentrations seems to exhibit promotive and suppressive actions on the process of cell death caused by H2O2. Ziram increased the number of living cells with exposed PS, a phenomenon characteristic of early stages of apoptosis. Thus, it is concluded that Ziram exhibits pseudo-cytoprotective actions against H2O2- induced oxidative stress

    Zinc is a determinant of the cytotoxicity of Ziram, a dithiocarbamate fungicide, in rat thymic lymphocytes : Possible environmental risk

    Get PDF
    Ziram, one of dithiocarbamate fungicides, is widely applied to agriculture because the agent protects various crops from fungal infections. Risks of dithiocarbamate biocide use are concerned. It was previously reported that Ziram increased the intracellular concentration of Zn2+. Therefore, we cytometrically studied the mechanism of Zn2+-dependent lethal actions of Ziram on rat lymphocytes under environmentally relevant Zn2+ levels. Membrane and cellular parameters of rat lymphocytes were estimated by flow-cytometric techniques with appropriate fluorescent probes. The Ziram-induced increase in cell lethality was completely attenuated by Zn2+ chelators. A significant raise of cell lethality was found on the simultaneous application of Ziram at a sublethal concentration and ZnCl2. The combination of Ziram and ZnCl2 increased the cellular superoxide anion content and decreased the cellular GSH content, which possibly caused the increase in cell lethality. The zinc concentrations under present experimental conditions were comparable to the environmentally relevant concentrations found in rivers. Therefore, the environmental level of zinc may be critical in estimating the toxicity of Ziram to wild animals

    Co-variation of fish and coral traits in relation to habitat type and fishery status

    Get PDF
    Escalating climate impacts on coral reefs are increasingly expanding management goals beyond preserving biodiversity to also maintaining ecosystem functions. Morphological and ecological species traits can help assess changes within reef communities beyond taxonomic identities alone. However, our limited understanding of trait interactions between habitat-building corals and associated reef fishes and whether they are captured by current monitoring practices hampers management. Here, we apply co-inertia analyses to test whether trait assemblages in corals and fishes co-vary across different habitats and test whether different components of the reef fish community (fisheries vs. non-target species) display distinct relationships. We find that spatial co-variation across habitat types between coral and fish traits is strengthened by the addition of non-target fishes. Additionally, even in fisheries with diverse targets, non-target species make unique contributions to the overall trait structure and highlight the importance of considering monitoring protocols when drawing conclusions about traits and ecosystems

    Noninvasive prediction of shunt operation outcome in idiopathic normal pressure hydrocephalus

    Get PDF
    Idiopathic normal pressure hydrocephalus (iNPH) is a syndrome characterized by gait disturbance, cognitive deterioration and urinary incontinence in elderly individuals. These symptoms can be improved by shunt operation in some but not all patients. Therefore, discovering predictive factors for the surgical outcome is of great clinical importance. We used normalized power variance (NPV) of electroencephalography (EEG) waves, a sensitive measure of the instability of cortical electrical activity, and found significantly higher NPV in beta frequency band at the right fronto-temporo-occipital electrodes (Fp2, T4 and O2) in shunt responders compared to non-responders. By utilizing these differences, we were able to correctly identify responders and non-responders to shunt operation with a positive predictive value of 80% and a negative predictive value of 88%. Our findings indicate that NPV can be useful in noninvasively predicting the clinical outcome of shunt operation in patients with iNPH

    Predominant sarcomatoid carcinoma of the lung concurrent with jejunal metastasis and leukocytosis

    Get PDF
    Sarcomatoid carcinoma is an extremely rare biphasic tumor characterized by a combination of malignant epithelial and mesenchymal cells. Limited data on sarcomatoid carcinoma showed that most cases occurred with advanced local disease and metastasis, and paraneoplastic syndromes were rare. We present the case of a 63-year-old man with lung sarcomatoid carcinoma associated with jejunum metastasis and leukocytosis, and its clinical, macroscopic, and histopathological features. This case emphasizes the importance of recognizing paraneoplastic syndromes and metastasis of sarcomatoid carcinoma at diagnosis

    Scale-free memory model for multiagent reinforcement learning. Mean field approximation and rock-paper-scissors dynamics

    Full text link
    A continuous time model for multiagent systems governed by reinforcement learning with scale-free memory is developed. The agents are assumed to act independently of one another in optimizing their choice of possible actions via trial-and-error search. To gain awareness about the action value the agents accumulate in their memory the rewards obtained from taking a specific action at each moment of time. The contribution of the rewards in the past to the agent current perception of action value is described by an integral operator with a power-law kernel. Finally a fractional differential equation governing the system dynamics is obtained. The agents are considered to interact with one another implicitly via the reward of one agent depending on the choice of the other agents. The pairwise interaction model is adopted to describe this effect. As a specific example of systems with non-transitive interactions, a two agent and three agent systems of the rock-paper-scissors type are analyzed in detail, including the stability analysis and numerical simulation. Scale-free memory is demonstrated to cause complex dynamics of the systems at hand. In particular, it is shown that there can be simultaneously two modes of the system instability undergoing subcritical and supercritical bifurcation, with the latter one exhibiting anomalous oscillations with the amplitude and period growing with time. Besides, the instability onset via this supercritical mode may be regarded as "altruism self-organization". For the three agent system the instability dynamics is found to be rather irregular and can be composed of alternate fragments of oscillations different in their properties.Comment: 17 pages, 7 figur

    Right ventricular dysfunction in patients with Brugada-like electrocardiography: a two dimensional strain imaging study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Sodium channel blockers augment ST-segment elevation in the right precordial leads in patients undergoing Brugada-type electrocardiography (ECG). However, their effect on echocardiographic features is not known. We address this by assessing global and regional ventricular function using conventional Doppler and two- dimensional (2D) speckle tracking techniques.</p> <p>Methods</p> <p>Thirty-one patients with Brugada-type ECG were studied. A pure sodium channel blocker, pilsicainide, was used to provoke an ECG response. The percentage longitudinal systolic myocardial strain at the base of both the right ventricular (RV) free wall and the interventricular septum wall was measured using 2D speckle tracking. Left ventricular (LV) and RV myocardial performance (TEI) indices were also measured.</p> <p>Results</p> <p>The pilsicainide challenge provoked a positive ECG response in 13 patients (inducible group). In the inducible group, longitudinal strain was significantly reduced only at the RV (-27.3 ± 5.4% vs -22.1 ± 3.6%, <it>P </it>< 0.01), and both RV and LV TEI indices increased (RV: 0.19 ± 0.09 vs 0.27 ± 0.11, <it>P </it>< 0.05; LV: 0.30 ± 0.10 vs 0.45 ± 0.10, <it>P </it>< 0.01) after pilsicainide administration.</p> <p>Conclusions</p> <p>Temporal and spatial analysis using the TEI index and 2D strain imaging revealed the deterioration of global ventricular function associated with conduction disturbance and RV regional function in patients with Brugada-type ECG and coved type ST elevation due to administration of a sodium channel blocker.</p
    corecore