Autophagy is implicated in the maintenance of cardiac homeostasis. Autophagy is activated in heart failure, in which reactive oxygen species (ROS) are increased. Exogenous ROS have been shown to induce cardiomyocyte autophagy alterations. However, little is known about the influences of physiological levels of endogenous ROS on cardiomyocyte autophagy. In the present study, we tested the hypothesis that endogenous ROS in cardiomyocytes play an important role in inducing autophagy. Cultured H9C2 cardiomyocytes or Sprague-Dawley rats were treated with the antioxidant N-acetyl-cysteine (NAC) or the superoxide dismutase mimic tempol under the basal or nutrient deprivation conditions. The autophagic flux was assessed by the lysosomal inhibitor chloroquine. In H9C2 cardiomyocytes, under a basal condition, NAC or tempol increased the ratio of LC3 II/I proteins and reduced LC3 II autophagic flux. Under nutrient deprivation, NAC increased the LC3 II/I ratio and reduced LC3 II autophagic flux. In vivo studies in rats, NAC treatment increased the LC3 II/I ratio and p-Akt protein expression in myocardium. We concluded that the antioxidants reduced autophagic flux in cardiomyocytes under the basal or nutrient deprivation conditions, suggesting that endogenous ROS promote autophagy flux under physiological conditions, and this effect is mediated, at least in part, through Akt inhibition., J.-P. Wang, R.-F. Chi, J. Liu, Y.-Z. Deng, X.-B. Han, F.-Z. Qin, B. Li., and Seznam literatury
Recent studies focused on epicardial fat, formerly relatively neglected component of the heart, have elucidated some of its key roles. It possesses several properties that can distinguish it from other adipose tissue depots. Its unique anatomical location in the heart predisposes the epicardial fat to be an important player in the physiological and biochemical regulation o f cardiac homeostasis. Obesity is associated with an increase in epicardial fat mass. Excess of cardiac fat can contribute to greater left ventricular mass and work, diastolic dysfunction and attenuated septal wall thickening. Imbalance in adipokines levels secreted in autocrine or paracrine fashion by epicardial fat can contribute to the activation of the key atherogenic pathways in the setting of metabolic syndrome. Epicardial fat has also been identified as an important source of pro-inflammatory mediato rs worsening endothelial dysfunction, eventually leading to coronary artery disease. Increased production of pro-inflammatory factors by epicardial fat can also contribute to systemic insulin resistance in patients undergoing cardiac surgery. Here we revie w the most important roles of epicardial fat with respect to heart disease in the context of other underlying pathologies such as obesity and type 2 diabetes mellitus., Z. Matloch, T. Kotulák, M. Haluzík., and Obsahuje bibliografii
We hypothesize that differences in fungal taxonomic groups may exert a direct influence on the composition of mycophagous insect communities, and that the relative importance of taxonomy compared to other fungal traits may change as the mushrooms decay. We conducted a 3-year field survey and analyzed the species composition of mycophagous insect communities using partial canonical correspondence analysis (partial CCA). We collected 2457 mushrooms belonging to 27 genera, and 4616 insects belonging to 16 families emerged from 439 of the mushrooms. For the whole insect community, fungal genera explained 10-19% of the total variance in the family composition of the insect communities of mushrooms at different developmental stages. Only the fungal genus Collybia significantly affected the community composition almost irrespective of developmental stage. In the drosophilid community, which consisted of 844 individuals from 9 species, fungal genera explained 19-34% of the total variance. Some fungal genera, such as Amanita and Collybia, affected the drosophilid community, but not at all developmental stages. The number of fungal genera that significantly affected the insect community composition did not differ among fungal stages both in the whole insect community and in the drosophilid community. Thus, our former hypothesis was supported by the present analysis, whereas the latter was not. However, the percentages of variance explained by fungal genera were rather small. This suggests that the importance of fungal genera is likely to be less significant than that of other selection pressures in determining the species composition of mycophagous insect communities.
The paper deals with the role of gender in the context of witchcraft. It focuses on the situation in a rural area in eastern Slovenia, where the author and her students researched witchcraft in 2000 and 2001. The meaning of a gender in witchcraft accusations is presented with respect to various levels and types of witch (social level - neighborhood witches, village witches; supernatural level – night witches; counter witches). Among neighborhood witches (about whom people believe that they perform some kind of magic: placing eggs etc. in the hope that they will hurt neighbors; intentional praise), women are typically assumed to be guilty; men appear only in the subcategory of people with evil eye. Similar holds for all the subcategories of village witches, except for those who earned their reputation because of the assumption of their possession of a book of magic (where men predominate). Night witches (in the form of lights or vague presences which make it difficult for people to find their way) are always female (they are spoken about using the feminine gender; when they are recognized as people from the village, they are always women). In contrast, the ratio of men to women among counterwitches, to whom people turned for help against witches, rises dramatically. The most influential counterwitch whom people visited in this area was a men. The relationship between the sexes can also be seen through an analysis of (migratory) legends about witches whereby many of them reveal a concealed misogyny.
An understanding of preferential flow in the vadose zone is crucial for the prediction of the fate of pollutants.
Infiltration basins, developed to mitigate the adverse effects of impervious surfaces in urban areas, are established above
strongly heterogeneous and highly permeable deposits and thus are prone to preferential flow and enhanced pollutant
transport. This study numerically investigates the establishment of preferential flow in an infiltration basin in the Lyon
suburbs (France) established over a highly heterogeneous glaciofluvial deposit covering much of the Lyon region. An investigation
of the soil transect (13.5 m long and 2.5 m deep) provided full characterization of lithology and hydraulic
properties of present lithofacies. Numerical modeling with the HYDRUS-2D model of water flow in the transect was
used to identify the effects of individual lithofacies that constitute the deposit. Multiple scenarios that considered different
levels of heterogeneity were evaluated. Preferential flow was studied for several values of infiltration rates applied
after a long dry period. The numerical study shows that the high contrast in hydraulic properties of different lithofacies
triggers the establishment of preferential flow (capillary barriers and funneled flow). Preferential flow develops mainly
for low water fluxes imposed at the surface. The role of individual lithofacies in triggering preferential flow depends on
their shapes (layering versus inclusions) and their sizes. While lenses and inclusions produce preferential flow pathways,
the presence of the surface layer has no effect on the development of preferential flow and it only affects the effective
hydraulic conductivity of the heterogeneous transect.
Hepatocyte nuclear factor 1-β is a transcription factor which plays a crucial role during ontogenesis in the differentiation of visceral endoderm from primitive endoderm, and is especially important for the normal development of the kidney, urogenital tract, gastrointestinal tract, liver, and pancreas. Despite the growing knowledge about the potential involvement of hepatocyte nuclear factor 1-β in the process of carcinogenesis, the exact underlying mechanism that would explain its rather varied effects in different tumours has not been sufficiently investigated. Most of the data regarding the significance of hepatocyte nuclear factor 1-β arise from genome-wide association studies and is concerned with the influence of single-nucleotide polymorphisms of hepatocyte nuclear factor 1-β on either the increased or decreased susceptibility to certain types of cancer. However, the influence of both the germinal and somatic mutations of this gene on the process of carcino-genesis is still poorly understood. According to current data, in some tumours hepatocyte nuclear factor 1-β acts as a protooncogene, while in others as a tumour suppressor gene, although the reasons for this are not clear. The exact incidence of hepatocyte nuclear factor 1-β mutations and the spectrum of
tumours in which they may play a role in the process of carcinogenesis remain unknown. From the practical point of view, immunohistochemical expression of hepatocyte nuclear factor 1-β can be used in differential diagnostics of certain tumours, especially clear cell carcinoma. In our article we review the current knowledge regarding the significance of hepatocyte nuclear factor 1-β in carcinogenesis. and Corresponding author: Michaela Bártů
Wound healing is a complex physiological process important for tissue homeostasis. An acute injury initiates massive cell migration, proliferation and differentiation, synthesis of extracellular matrix components, scar formation and remodelling. Blood flow and tissue oxygenation are parts of the complex regulation of healing. Higher organisms utilize molecular oxygen as a terminal oxidant. This way of gaining energy for vital processes such as healing leads to the production of a number of oxygen compounds that may have a defensive or informatory role. They may be harmful when present in high concentrations. Both the lack and the excess of reactive oxygen species may influence healing negatively., Jiří Kanta, and Literatura 6
Cardiovascular studies have confirmed that hydrogen sulphide (H2S) is involved in various signaling pathways in both physiological and pathological conditions, including hypertension. In contrast to nitric oxide (NO), which has a clear vasorelaxant action, H2S has both vasorelaxing and vasoconstricting effects on the cardiovascular system. H2S is an important antihypertensive agent, and the reduced production of H2S and the
alterations in its functions are involved in the initiation of spontaneous
hypertension. Moreover, cross-talk between H2S and NO has been reported. NO-H2S interactions include reactions between the molecules themselves, and each has been shown to regulate the endogenous production of the other. In addition, NO and H2S can interact to form a nitrosothiol/s complex, which has original properties and represents a novel nitroso-sulphide signaling pathway. Furthermore, recent results have shown that the interaction between H2S and NO could be involved in the endothelium-regulated compensatory mechanisms that are observed in juvenile spontaneously hypertensive rats. The present review is devoted to role of H2S in vascular tone regulation. We primarily focus on the mechanisms of H2S-NO interactions and on the role of H2S in blood pressure regulation in normotensive and spontaneously hypertensive rats.