Atherosclerosis retains the leading position among the causes of global morbidity and mortality worldwide, especially in the industrialized countries. Despite the continuing efforts to investigate ...disease pathogenesis and find the potential points of effective therapeutic intervention, our understanding of atherosclerosis mechanisms remains limited. This is partly due to the multifactorial nature of the disease pathogenesis, when several factors so different as altered lipid metabolism, increased oxidative stress, and chronic inflammation act together leading to the formation and progression of atherosclerotic plaques. Adequate animal models are currently indispensable for studying these processes and searching for novel therapies. Animal models based on rodents, such as mice and rats, and rabbits represent important tools for studying atherosclerosis. Currently, genetically modified animals allow for previously unknown possibilities in modelling the disease and its most relevant aspects. In this review, we describe the recent progress made in creating such models and discuss the most important findings obtained with them to date.
Animal models of diseases are invaluable tools of modern medicine. More than forty years have passed since the first successful experiments and the spectrum of available models, as well as the list ...of methods for creating them, have expanded dramatically. The major step forward in creating specific disease models was the development of gene editing techniques, which allowed for targeted modification of the animal's genome. In this review, we discuss the available tools for creating transgenic animal models, such as transgenesis methods, recombinases, and nucleases, including zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN), and CRISPR/Cas9 systems. We then focus specifically on the models of atherosclerosis, especially mouse models that greatly contributed to improving our understanding of the disease pathogenesis and we outline their characteristics and limitations.
In the modern world, cardiovascular diseases have a special place among the most common causes of death. Naturally, this widespread problem cannot escape the attention of scientists and researchers. ...One of the main conditions preceding the development of fatal cardiovascular diseases is atherosclerosis. Despite extensive research into its pathogenesis and possible prevention and treatment strategies, many gaps remain in our understanding of this disease. For example, the concept of multiple low-density lipoprotein modifications was recently stated, in which desialylation is of special importance. Apart from this, sialic acids are known to be important contributors to processes such as endothelial dysfunction and inflammation, which in turn are major components of atherogenesis. In this review, we have collected information on sialic acid metabolism, analyzed various aspects of its implication in atherosclerosis at different stages, and provided an overview of the role of particular groups of enzymes responsible for sialic acid metabolism in the context of atherosclerosis.
A new technique of detection of dark photons as cold dark matter by means of a multicathode counter is described. The first results obtained with the aid of this technique are presented. Also, its ...potential for providing evidence on the basis of searches for symmetry in the time distribution of diurnal variations because of the rotation of the Earth in the stellar reference frame for the rate of counting of single electrons emitted from the metallic cathode of the counter via the conversion of dark photons is discussed.
Role of androgens in cardiovascular pathology Chistiakov, Dimitry A; Myasoedova, Veronika A; Melnichenko, Alexandra A ...
Vascular health and risk management,
01/2018, Letnik:
14
Journal Article
Recenzirano
Odprti dostop
Cardiovascular effects of android hormones in normal and pathological conditions can lead to either positive or negative effects. The reason for this variation is unknown, but may be influenced by ...gender-specific effects of androids, heterogeneity of the vascular endothelium, differential expression of the androgen receptor in endothelial cells (ECs) and route of androgen administration. Generally, androgenic hormones are beneficial for ECs because these hormones induce nitric oxide production, proliferation, motility, and growth of ECs and inhibit inflammatory activation and induction of procoagulant, and adhesive properties in ECs. This indeed prevents endothelial dysfunction, an essential initial step in the development of vascular pathologies, including atherosclerosis. However, androgens can also activate endothelial production of some vasoconstrictors, which can have detrimental effects on the vascular endothelium. Androgens also activate proliferation, migration, and recruitment of endothelial progenitor cells (EPCs), thereby contributing to vascular repair and restoration of the endothelial layer. In this paper, we consider effects of androgen hormones on EC and EPC function in physiological and pathological conditions.
Phosphate ore are a complex combination of chemical substances in natural minerals. The complicated physicochemical process of heating phosphorites includes a set of heat and mass exchange processes, ...endothermic reactions of carbonates dissociation, and processes of structural transformations during solid- and liquid-state sintering. The temperature-concentration and temperature-time dependences of the heat capacity of phosphate ore samples on the thermal conditions of the carbonates dissociation reaction in the samples, under structural modifications, as a result of a change in the chemical composition of the samples were experimentally investigated. The influence of the structural changes in the samples in the range of the raw material roasting temperatures and of the heating rates on the heat capacity of the phosphorites was evaluated. Scientific justification was provided for the occurrence of significant temperature gradients in the samples due to transient heating conditions and to the action of the thermal effects of the carbonates dissociation reaction, which limits the applicability of conventional methods to determine the true and effective heat capacities of the samples. The relationship between the heterogeneous endothermic structural transformations and the thermophysical conditions of the endothermic reaction of carbonates dissociation was established, which allows increasing the energy efficiency of the thermal treatment of the phosphate raw material during beneficiation on roasting conveyor and sintering machines. Analysis of the experimental data reveals a significant effect of thermal dissociation of carbonates and of the internal heat exchange on the heat capacity of the phosphorites. The error of the found heat capacity is determined by the technique of thermoanalytical experiments, the dimensions of the samples, the thermal effect of the carbonates dissociation reaction, and the reacting phase concentration. The error increases with an increase in the sample heating rate, i.e., with growth of the factors increasing the steepness of the temperature gradient field in the samples. The chemical and energy technological features of the thermal treatment of the phosphate raw materials are determined by the dependence of their heat capacity on the endothermic reaction of carbonates dissociation during heating in a wide range of heating rates in a moving dense multilayer of pellets on the grate of operating roasting conveyor machines, which allows optimizing energy-saving roasting modes.
The method of measurements is described that has been performed using a multicathode counter with an iron cathode. The aim of experiment was to search for diurnal variations of the count rate of ...single electrons emitted from the surface of the cathode by the conversion of dark photons on its surface. The results obtained during 160 days of measurements are presented.
Polymorphic Modifications of Chitosan Baklagina, Y. G.; Klechkovskaya, V. V.; Kononova, S. V. ...
Crystallography reports,
05/2018, Letnik:
63, Številka:
3
Journal Article
Recenzirano
This work describes the analysis of the crystal structures of chitosan, its main polymorphic modifications, and its characteristic mutual chain packing and hydrogen bond systems in the crystalline ...regions of conformers. The analysis takes into consideration the crystal structures of chitosan complexes (salts) with organic and inorganic acids and their structural transformations. Notably, the transformation of the hydrated form of chitosan into anhydrous is found to be irreversible and occurs either at high temperatures or through a less stable form of hydrated salts. The interaction with polyanions during the formation of multilayer films can be considered as a way to form the anhydrous crystalline form of chitosan.
A method for preparing multilayer film composites based on chitosan has been developed by the example of polymer pairs: chitosan–hyaluronic acid, chitosan–alginic acid, and chitosan–carrageenan. The ...structure of the composite films is characterized by X-ray diffractometry and scanning electron microscopy. It is shown that the deposition of a solution of hyaluronic acid, alginic acid, or carrageenan on a chitosan gel film leads to the formation of a polyelectrolyte complex layer at the interface, which is accompanied by the ordering of chitosan chains in the surface region; the microstructure of this layer depends on the nature of contacting polymer pairs.
Vladivostok city and its surrounding areas have previously experienced rainfall-induced landslides, which have caused significant casualties and damage in high-density urban areas. As a result of ...anthropogenic factors, steep slopes in some areas reach 90°, which significantly affects the slope stability. The authors collected all available historical data about landslide incidents in the study area. A predictive model was derived using logistic regression and data on antecedent rainfall, cumulative precipitation, and daily rainfall intensity. The resulting model has relatively low precision and recall, which may reflect the lack of slope material parameters. Nonetheless, the balanced accuracy of 78% allows rainfall to be considered the most important causative factor of slope instability. The main advantage of the predictive model lies in its simplified mathematical expression and input rainfall data set based on measurements from one station with 24-h granularity. These results show promise for the further implementation of the model for the purpose of early warning.
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