625 research outputs found

    Iron concentrations in atherosclerotic plaque and serum in patients with carotid atherosclerosis

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    The aim of this study was to investigate the iron concentrations in serum and carotid plaque in patients with different morphology of carotid atherosclerotic plaque and compared with other metal ions. Carotid endarterectomy due to the significant atherosclerotic stenosis was performed in 91 patients. Control group consisted of 27 patients, without carotid atherosclerosis. Atherosclerotic plaques were divided into four morphological groups, according to ultrasonic and intraoperative characteristics. Iron, copper and zinc concentration in plaque, carotid artery and serum were measured by spectrophotometry. Serum iron concentrations were higher in patients with hemorrhagic plaques in comparison to the control group (4.7 μmol/l ± 1.2 vs. 2.1 μmol/l ± 0.8, p < 0.05). Iron concentrations were higher in patients with hemorrhagic plaques in comparison to fibrolipid plaques (72.1 ± 14.3 μg/g vs. 39.3 ± 22.9 μg/g; p < 0.05). Negative significant correlation was found for zinc in serum and plaque iron concentration in patients (p < 0.05). We also demonstrated positive significant correlation for copper and iron in serum (p < 0.05). The data obtained in the current study are consistent with the hypothesis that high iron levels may contribute to atherosclerosis and its complications as factors in a multifactorial disease

    Lie group weight multiplicities from conformal field theory

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    Dominant weight multiplicities of simple Lie groups are expressed in terms of the modular matrices of Wess-Zumino-Witten conformal field theories, and related objects. Symmetries of the modular matrices give rise to new relations among multiplicities. At least for some Lie groups, these new relations are strong enough to completely fix all multiplicities.Comment: 12 pages, Plain TeX, no figure

    The Effects of Different Doses of Sildenafil on Coronary Blood Flow and Oxidative Stress in Isolated Rat Hearts

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    The dose-response relationship of sildenafil effects on cardiac function is not completely elucidated. The aim of this study was to assess the effects of different doses of sildenafil on coronary flow and oxidative stress in isolated rat hearts. Coronary flow and markers of oxidative stress, including nitrite outflow, and superoxide anion production in coronary effluent, were determined for isolated rat hearts. The experiments were performed during control conditions and in the presence of sildenafil (10, 20, 50, 200 nM) alone or with Nω-nitro-L-arginine monomethyl ester (L-NAME) (30 μM). Sildenafil was shown to result in a significant increase in coronary flow at lower coronary perfusion pressure (CPP) values at all administered doses, whereas, with an increase in CPP, a reduction in coronary flow was observed. An increase in nitric oxide (NO) was most pronounced in the group treated with the lowest dose of sildenafil at the highest CPP value. After the inhibition of the NO-cyclic guanosine monophosphate (cGMP) signaling (NOS) system by L-NAME, only a dose of 200 nM sildenafil was high enough to overcome the inhibition and to boost release of O2−. That effect was CPP-dependent, with statistical significance reached at 80, 100 and 120 mmHg. Our findings indicate that sildenafil causes changes in heart vasculature in a dose-dependent manner, with a shift from a vasodilatation effect to vasoconstriction with a pressure increase. The highest dose administered is capable of producing superoxide anion radicals in terms of NOS system inhibition

    The influence of the methanol extract of Galium verum on cardiac oxidative damage in hypertensive rats in a model of global ischemia

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    Galium verum (G. verum, Lady ҆s bedstraw) is a perennial herbaceous plant that has been used for centuries as a sedative, an anticancer agent, in the treatment of gout, epilepsy, as antioxidant. Previous studies confirmed cardioprotective properties of this plant species extract in animal models of heart dysfunction, however, the impact of G. verum consumption on cardiac redox state in a condition of global ischemia has not been fully clarified. Therefore, our goal was to examine the effect of G. verum methanol extract on cardiac redox state in spontaneously hypertensive rats in the model of global ischemia. The study involved 20 Wistar kyoto spontaneously hypertensive rats, divided into a control (CTRL) and an experimental group (GVE). CTRL group included untreated rats, while the GVE group included rats that received 100 mg/kg of the methanol extract of G. verum for 14 days. After the treatment protocol, animals were sacrificed, and the hearts of all rats were isolated and subjected to 20-minute ischemia followed by a 30-minute reperfusion period. After accomplishment of the experimental protocol (ex vivo ischemia-reperfusin injury), heart tissue samples were used to determine the markers of cardiac oxidative stress such as superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and index of lipid peroxidation (TBARS). The results have shown that methanol extract of G. verum increased the level of GSH and the activity of SOD and CAT in the experimental group, while reduced TBARS levels compared to the CTRL group. It might be concluded that treatment with G. verum extract can attenuate oxidative damage resulting from ischemia-reperfusion injury in the hearts of spontaneously hypertensive rats.Publishe

    BRICs Nations Growing Impact on the Global Health Sector

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    The most notable feature of the past five centuries of global economic history dating back from Colonial Age until the present accelerated globalization is the persistence of «North–South» division between the global rich and poor. This ground pattern has been falling apart over the last three decades with the rise of BRICs emerging economies (Brazil, Russia, India, China). The Chinese Belt and Road Initiative fosters further rapid growth and synergy among these large nations. This ambitious and historically unprecedented infrastructural project if successful can lead to a formation by 2049 of a huge common economic zone bringing opportunities for multilateral development to the BRICs. These profound changes have deep implications for the global health care sector. Previous research on health and pharmaceutical spending has clearly documented that low- and middle-income economies (LMICs), led by these emerging markets, have doubled their share in global health spending from roughly 20% up to approximately 40% in purchasing power parity terms. Alongside with these global developments, a decade ago, some of the leading Western academic centers, confirm new era of rising world’s geo-economic and geopolitical multipolarity. The world witnesses this process being accelerated today and seek deeper understanding how it will reflect on long term health and pharmaceutical expenditure trends, particularly in the leading BRICs emerging markets being a front runner of such evolution.The authors declare absence of conflict of interests

    The role of hydrogen sulfide in homocysteine-induced cardiodynamic effects and oxidative stress markers in the isolated rat heart

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    This study aimed to assess the role of H2S in homocysteine-induced cardiodynamic effects in the isolated rat heart. The hearts were retrogradely perfused according to the Langendorff technique. The maximum and minimum rates of pressure in the left ventricle (dp/dt max, dp/dt min), systolic and diastolic left ventricular pressures (SLVP, DLVP), heart rate (HR), and coronary flow (CF) were measured. A spectrophotometrical method was used to measure the following oxidative stress markers: index of lipid peroxidation (thiobarbituric acid reactive substances, TBARS), nitrite level (NO2−), superoxide anion radicals (O2•−), and hydrogen peroxide (H2O2) concentrations. The administration of 10 µmol/l DL-homocysteine (DL-Hcy) alone decreased dp/dt max, SLVP, and CF but did not change any oxidative stress parameters. The administration of 10 µmol/l DL-propargylglycine (DL-PAG) decreased all cardiodynamic parameters and increased the concentration of O2•−. The co-administration of DL-Hcy and DL-PAG induced a significant decrease in all estimated cardiodynamic parameters and decreased the concentration of NO2− and O2•− but increased the levels of TBARS and H2O2. Homocysteine shows a lower pro-oxidative effect in the presence of hydrogen sulfide (H2S), which indicates a potential anti-oxidative capacity of H2S

    A Minimal Threshold of c-di-GMP Is Essential for Fruiting Body Formation and Sporulation in Myxococcus xanthus

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    Generally, the second messenger bis-(3’-5’)-cyclic dimeric GMP (c-di-GMP) regulates the switch between motile and sessile lifestyles in bacteria. Here, we show that c-di-GMP is an essential regulator of multicellular development in the social bacterium Myxococcus xanthus. In response to starvation, M. xanthus initiates a developmental program that culminates in formation of spore-filled fruiting bodies. We show that c-di-GMP accumulates at elevated levels during development and that this increase is essential for completion of development whereas excess c-di-GMP does not interfere with development. MXAN3735 (renamed DmxB) is identified as a diguanylate cyclase that only functions during development and is responsible for this increased c-di-GMP accumulation. DmxB synthesis is induced in response to starvation, thereby restricting DmxB activity to development. DmxB is essential for development and functions downstream of the Dif chemosensory system to stimulate exopolysaccharide accumulation by inducing transcription of a subset of the genes encoding proteins involved in exopolysaccharide synthesis. The developmental defects in the dmxB mutant are non-cell autonomous and rescued by co-development with a strain proficient in exopolysaccharide synthesis, suggesting reduced exopolysaccharide accumulation as the causative defect in this mutant. The NtrC-like transcriptional regulator EpsI/Nla24, which is required for exopolysaccharide accumulation, is identified as a c-diGMP receptor, and thus a putative target for DmxB generated c-di-GMP. Because DmxB can be—at least partially—functionally replaced by a heterologous diguanylate cyclase, these results altogether suggest a model in which a minimum threshold level of c-di-GMP is essential for the successful completion of multicellular development in M. xanthus
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