112,136 research outputs found
Molecular mechanisms of cadmium-induced nonspecific mitochondrial permeability
No full textIn mitochondria obtained from the rat liver, we confirmed the ability of Cd2+ to induce the development of nonspecific mitochondrial permeability (NMP). A kinetic analysis of this process was performed. We demonstrated that the cadmium-induced NMP is mediated by activation of megachannels (mitochondrial transition permeability pores) and is realized with the participation of porin, the ADP/ATP antiporter, and cyclophilin D. A key event in the process of induction of the mitochondrial pore opening is interaction of Cd2+ with just the ADP/ATP antiporter. © 2012 Springer Science+Business Media, Inc
Mechanisms underlying interaction of zinc, lead, and cobalt with nonspecific permeability pores in the mitochondrial membranes
No full textIt was demonstrated that Zn 2+, in contrast to Pb 2+ and Co 2+, initiates the development of the nonspecific mitochondrial permeability (NMP) in hepatocytes. Kinetic analysis of this process was performed. It was proved that Zn-induced NMP is mediated by activation of megachannels (mitochondrial permeability transition pores). Sulfo groups of the ADP/ATP antiporter and carboxylic groups of voltage-dependent anionic channels are also involved in the development of Zn 2+-stimulated NMP. Interaction between Zn 2+ and cyclophilin D is the key event in the process of activation of NMP. We found that the Na/Ca exchanger exerts an activating effect on the Zn-induced NMP. In general, swelling of the mitochondria and Ca 2+ release from these organelles under the action of Zn 2+ are based on noticeably dissimilar mechanisms. The observed distinctions depend on the functional state of the mitochondrial transport systems. © 2011 Springer Science+Business Media, Inc
INVESTIGATION OF THE TRICYCLE TRACTOR INCLINE INFLUENCE ON ITS STABILITY UNDER THE CONDITIONS OF WORK AT THE OF SLOPE FIELDS
No full textSheychenko V., Hailis G., Dudnikov I., Fedirko P. Investigation of the tricycle tractor incline influence on its stability under the conditions of work at the of slope fields. Independent journal of management s production. v. 10, n. 7. 2019. p.725-737. (Web of Science
Внесок Na+/Ca2+-обмінника у процеси Cа2+- та Cd2+-індукованої активації мітохондріальної пори перехідної проникності
No full textINVESTIGATION OF THE TRICYCLE TRACTOR INCLINE INFLUENCE ON ITS STABILITY UNDER THE CONDITIONS OF WORK AT THE OF SLOPE FIELDS
No full textSheychenko V., Hailis G., Dudnikov I., Fedirko P. Investigation of the tricycle tractor incline influence on its stability under the conditions of work at the of slope fields. Independent journal of management s production. v. 10, n. 7. 2019. p.725-737. (Web of Science
Dietary flavonoid, lignan and antioxidant capacity and risk of hepatocellular carcinoma in the European prospective investigation into cancer and nutrition study
No full textLimited epidemiological evidence suggests a protective role for plant foods rich in flavonoids and antioxidants in hepatocellu- lar cancer (HCC) etiology. Our aim was to prospectively investigate the association between dietary intake of flavonoids, lignans and nonenzymatic antioxidant capacity (NEAC) and HCC risk. Data from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort including 477,206 subjects (29.8% male) recruited from ten Western European countries, was analyzed. Flavonoid, lignan and NEAC intakes were calculated using a compilation of existing food composition databases linked to dietary information from validated dietary questionnaires. Dietary NEAC was based on ferric reducing antioxidant capacity (FRAP) and total radical-trapping antioxidant parameter (TRAP). Hepatitis B/C status was measured in a nested case– control subset. During a mean follow-up of 11-years, 191 incident HCC cases (66.5% men) were identified. Using Cox regres- sion, multivariable adjusted models showed a borderline nonsignificant association of HCC with total flavonoid intake (highest versus lowest tertile, HR 5 0.65, 95% CI: 0.40–1.04; ptrend 5 0.065), but not with lignans. Among flavonoid subclasses, flava- nols were inversely associated with HCC risk (HR 5 0.62, 95% CI: 0.39–0.99; ptrend 5 0.06). Dietary NEAC was inversely associ- ated with HCC (FRAP: HR 0.50, 95% CI: 0.31–0.81; ptrend 5 0.001; TRAP: HR 0.49, 95% CI: 0.31–0.79; ptrend 5 0.002), but statistical significance was lost after exclusion of the first 2 years of follow-up. This study suggests that higher intake of die- tary flavanols and antioxidants may be associated with a reduced HCC risk
Role of carboxylic groups in the control of nonspecific permeability of mitochondrial membranes
No full textIonized COOH groups are present in molecular structures involved in the process of formation of mitochondrial permeability transition pores (MPTPs), in particular, in the ADP/ATP antiporter and/or voltage-dependent anion channels. In experiments on preparations of isolated mitochondria obtained from rat hepatocytes, we found that, in the case of induction of nonspecific permeability through mitochondrial membranes under the action of Ca2+ in a relatively low concentration (15 μM), modulation of the activity of COOH groups with the use of 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (1 mM) led to unidirectional effects, namely to acceleration of the processes of formation of MPTPs and transport of incubation solution and Ca2+ through these megachannels, prolongation of the open state of the latter, as well as to increases in the final volume (swelling) of the mitochondria and to a rise in the amount of Ca2+ released from these organelles. In contrast, when calcium was used in a high concentration (100 μM), the directions of the above processes were dissimilar. Slowing down of the flow of incubation solution through MPTPs and the process of their formation was observed; at the same time, Ca2+ release from the mitochondria was accelerated. However, the final volume of the mitochondria and the amount of Ca2+ released from these cellular structures increased. Differences between the effects of the used modulator of the activity of COOH groups on the nonspecific permeability of the mitochondria induced by calcium applied in low and high concentrations are perhaps determined by the following. The process of swelling of the mitochondria is saturable, while Ca2+ release from these organelles shows an unlimited pattern. The latter process (Ca2+ release) probably undergoes calcium-initiated inactivation. The mechanisms of induction of nonspecific permeability of the mitochondrial membranes under the action of low and high calcium concentrations differ from each other. The calcium uniporter in the mitochondria is sensitive to the modulator of the activity of COOH groups. Diffusion of water through the inner mitochondrial membrane and/or other systems provides some contribution to the studied processes; this can lead to changes in the transport of liquids in these organelles. © 2010 Springer Science+Business Media, Inc
Kinetic analysis of the calcium- and cadmium-induced development of nonspecific permeability of the mitochondrial inner membrane
No full textWe studied the Ca2+- and Cd2+-induced development of the nonspecific permeability of the mitochondrial inner membrane in preparations obtained from rat liver tissue, which is accompanied by swelling of these organelles and intensification of light dispersion of their suspension. Addition of 5 to 100 μM Ca2+ or 1 to 50 μM Cd2+ to the medium caused swelling of the mitochondria. With increase in concentrations of Ca2+ and Cd2+, the latency of the effect decreased, and the rate of swelling of these organelles increased. Upon isolated action of Cd2+, the intensity of the process (amplitude of changes) did not depend significantly on the concentration of the above ions, while upon isolated action of Cd2+, it was the maximum at the concentration of 1 mM and noticeably decreased with increase in the concentration. The dependence of the rate of Ca2+- and Cd2+-induced swelling of the mitochondria on the concentration of these ions was described by power and sigmoid functions, respectively. The calculated maximum rate and the constant of 50% saturation of these processes were equal to 0.609 and 1.084 extinction units/min·mg protein and 19.85 and 7.28 μM for Ca2+- and Cd2+-induced swelling of the mitochondria, respectively. Cyclosporine A (10 μM) uppressed completely the Ca2+-induced swelling of the mitochondria and decreased only partly the Cd2+-induced swelling. Dithiothreitol (1 mM) inhibited completely the latter effect but did not influence significantly the Ca2+-stimulated process. Therefore, the distinctions between the kinetics of Ca2+- and Cd2+-induced swelling of the mitochondria, as well as the different sensitivity of these processes to cyclosporine A and dithiothreitol, prove that the mechanisms underlying interactions between the cations of the above metals and the inner mitochondrial membrane in the course of the development of nonspecific permeability of these organelles are dissimilar. © 2008 Springer Science+Business Media, Inc
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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