74 research outputs found
Application of sociological methods and implements in distance learning of the staff of municipal libraries of Sverdlovsk region
The article examines the question of the application of methods and implements of sociology in the e-learning system of additional education. The author speaks of applying sociology in the library. Attention is paid to the monitoring of the process of distance learning of the staff of municipal libraries. The author discusses how feedback can be provided.В статье анализируется вопрос применения методов и инструментов социологии в дистанционной системе дополнительного образования. Автор говорит о применении социологии в библиотеке. Уделяется внимание проведению контроля в процессе дистанционного обучения сотрудников муниципальных библиотек. Рассматривается, как может осуществляться обратная связь
Mechano-Electric Feedbacks in a New Model of the Excitation-Contraction Coupling in Human Cardiomyocytes
The study is aimed to develop a new human cardiomyocyte model, which describes electromechanical coupling and mechano-electric feedbacks. The combined electromechanical model (TP+M) links the TP06 electrophysiological model of the human cardiomyocyte with our earlier developed model of the myocardium mechanical activity and its calcium regulation. In the TP+M model, we tried to maintain principal features of calcium transients and action potentials during the twitches typical for the human cardiomyocytes. The developed TP+M model allows simulating several basic classic phenomena such as load-dependent relaxation and length-dependence of isometric twitches and respective changes in action potential duration. We have also simulated some age-dependent changes in the electrical and mechanical activity in the human cardiomyocytes. © 2018 Creative Commons Attribution.The work was carried out within the framework of the IIP UrB RAS themes (Nos. AAAA-A18-118020590031-8, АААА-А18-118020590134-6) and was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0006, and by RFBR (18-01-00059 - single cell modeling; 18-015-00368 – ageing simulation)
Mechano-calcium and mechano-electric feedbacks in the human cardiomyocyte analyzed in a mathematical model
Experiments on animal hearts (rat, rabbit, guinea pig, etc.) have demonstrated that mechano-calcium feedback (MCF) and mechano-electric feedback (MEF) are very important for myocardial self-regulation because they adjust the cardiomyocyte contractile function to various mechanical loads and to mechanical interactions between heterogeneous myocardial segments in the ventricle walls. In in vitro experiments on these animals, MCF and MEF manifested themselves in several basic classical phenomena (e.g., load dependence, length dependence of isometric twitches, etc.), and in the respective responses of calcium transients and action potentials. However, it is extremely difficult to study simultaneously the electrical, calcium, and mechanical activities of the human heart muscle in vitro. Mathematical modeling is a useful tool for exploring these phenomena. We have developed a novel model to describe electromechanical coupling and mechano-electric feedbacks in the human cardiomyocyte. It combines the 'ten Tusscher-Panfilov' electrophysiological model of the human cardiomyocyte with our module of myocardium mechanical activity taken from the 'Ekaterinburg-Oxford' model and adjusted to human data. Using it, we simulated isometric and afterloaded twitches and effects of MCF and MEF on excitation-contraction coupling. MCF and MEF were found to affect significantly the duration of the calcium transient and action potential in the human cardiomyocyte model in response to both smaller afterloads as compared to bigger ones and various mechanical interventions applied during isometric and afterloaded twitches. © 2020 The Author(s).Russian Foundation for Basic Research, RFBR: 18‑01‑00059The work was carried out within the framework of the IIP UrB RAS themes (Nos. AAAA‑A18‑118020590031‑8, AAAA‑A18‑118020590134‑6) and was supported by RFBR (18‑01‑00059) and by Act 211 Government of the Russian Federation, contract No. 02.A03.21.0006
Russian Product Quality Standards
This article is devoted to the issues of the scope of application of various quality standards in the Russian Federation.Настоящая статья посвящена рассмотрению вопросов сферы применения различных стандартов качества в Российской Федерации
Transmural cellular heterogeneity in myocardial electromechanics
Myocardial heterogeneity is an attribute of the normal heart. We have developed integrative models of cardiomyocytes from the subendocardial (ENDO) and subepicardial (EPI) ventricular regions that take into account experimental data on specific regional features of intracellular electromechanical coupling in the guinea pig heart. The models adequately simulate experimental data on the differences in the action potential and contraction between the ENDO and EPI cells. The modeling results predict that heterogeneity in the parameters of calcium handling and myofilament mechanics in isolated ENDO and EPI cardiomyocytes are essential to produce the differences in Ca2+ transients and contraction profiles via cooperative mechanisms of mechano-calcium-electric feedback and may further slightly modulate transmural differences in the electrical properties between the cells. Simulation results predict that ENDO cells have greater sensitivity to changes in the mechanical load than EPI cells. These data are important for understanding the behavior of cardiomyocytes in the intact heart. © 2017, The Physiological Society of Japan and Springer Japan.Japan Society for the Promotion of Science, JSPS: 16K1287
Electromechanical coupling in cardiomyocytes depends on its electrotonic interaction with fibroblasts
Cardiac fibroblasts can influence cardiomyocyte electrical activity. Existing mathemati-cal models of fibroblast-cardiomyocyte interaction allow analyzing only electrical responses of effect cardiomyocytes and fibroblasts to their electrical interaction. In our work, we exam-ined fibroblast on the cardiomyocyte mechanics by modelling. We got significant changes in both action potential duration and force generation in the cardiomyocyte depending on the number of fibroblasts connected with it.The work was carried out within the IIF UrB RAS theme No AAAA-A18-118020590031-8, and was supported by the Russian Foundation for Basic Research (18-29-13008, 18-01-00059, 18-015-00368) and by RF Government Act #211 of March 16, 2013 (agreement 02.A03.21.0006)
Effects of GLP-1RAs on cardiovascular outcomes in patients with type 2 diabetes mellitus: review of real-world data on target populations from diabetes registry in Russian Federation
RATIONALE. Over the past 20 years the prevalence of type 2 diabetes in Russia has more than doubled and reached 4.43 million people in 2020, while the growth rate keeps increasing. Most patients with T2DM are at a higher risk of developing major adverse cardiovascular events (MACE) associated with significant mortality. There is a strong evidence base that the drugs belonging to GLP-1RA class contribute to reducing the risk of cardiovascular events and renal outcomes. At the same time, the current prescribing rates of these treatments in Russia are quite low - only about 0.1% of patients are prescribed GLP-1RAs, according to Diabetes Registry data.AIM. Review the results of several randomized clinical trials (RCTs) concerning effects of GLP-1RA treatments on prevention of primary and secondary cardiovascular events and estimate the number of diabetic target population.MATERIALS AND METHODS. We examined the data from clinical trials on GLP-1RA treatments registered in Russia and used in routine clinical practice (ELIXA, EXSCEL, LEADER, SUSTAIN-6 and REWIND) and data from two meta-analyzes published as of December 1, 2020. The task was to evaluate the inclusion criteria, patient profile, and the clinical efficacy and safety profiles of the studied therapies. Also, the analysis of clinical information from the Diabetes Registry (DR) was performed to estimate the number of target T2DM patients meeting RCTs inclusion criteria that could benefit from prescribing of GLP-1RAs.RESULTS. The reviewed clinical trials demonstrated a statistically significant reduction (p <0.05) in the risk of serious cardiovascular events in patients treated with Liraglutide [RR 0.87 (95% CI, 0.78-0.97)], Semagltuide [OP 0.74 (95% CI 0.58-0.95)] and Dulaglutide [RR 0.88 (95% CI 0.79-0.99)]. Meta-analyzes utilizing data from 6 RCTs with the total number of 56,004 T2DM patients, also, confirmed a statistically significant reduction in the risk of developing MACE (by 12%) in the studied population, and a 17% reduction in the risk of combined renal outcomes [RR 0.83 (95% CI 0.78-0.89), p <0.0001]. The DR patient population that met the RCTs inclusion criteria amounted to 538.6 thous. subjects in case of REWIND and 432.4 thous. in case of LEADER and SUSTAIN-6. The key differences between FDR patients and patients engaged in RCTs included gender and age characteristics. The DR patients were generally older and the bulk of them were women, which has to do with overall Russian demographic trends. The proportion of DR patients with established CVD was 26%, which closely matched the profile of patients from REWIND study (31.5%). According to DR data, the number of patients in whom the treatment was intensified following prescription of basal insulin was 7612 per year, which is close to a potential cohort eligible for alternative treatment with GLP-1RAs.CONCLUSION. All the drugs belonging to GLP-1RA class are clinically effective in reducing the risk of cardiovascular and renal outcomes, while demonstrating a favorable safety profile including with respect to lower risk of developing hypoglycemia. The decreased risk of complications was recorded both in patients with existing cardiovascular risks and patients with established CVD. Of all GLP-1RA treatments available in Russia at this point, the greatest clinical effectiveness is achieved by Liraglutide, Semaglutide and Dulaglutide. The estimated patient population from DR, meeting RCTs inclusion criteria and matching RCTs patient profile was over 500, 000 people with the largest number of patients meeting the REWIND criteria. The target population of patients with T2DM who may potentially benefit from the administration of GLP-1RAs is over 500, 000 people. Out of that number at least 7.5 thousand are patients, whose treatment is intensified following prescription of basal insulin (with an aim of improving glycemic control, but without consideration of cardiovascular risks).Currently, if we take the real world clinical setting in Russia, the number of patients receiving GLP-1RA treatments is substantially lower than the estimated figures (less than 1%), which requires reconsideration of the approach toward their prescribing as is recommended by state-of-the-art clinical guidelines prioritizing prevention of cardiovascular risks
The role of renin-angiotensin system and angiotensin-converting enzyme 2 (ACE2) in the development and course of viral infection COVID-19 in patients with diabetes mellitus
The role of renin-angiotensin system (RAS) in general and angiotensin-converting enzyme 2 (ACE2) in particular in the pathogenesis and course of viral infection caused by SARS-CoV-2 (COVID-19) is of particular interest. This is due not only to the fact that ACE2 is a receptor for the virus the target cells. RAS hyperactivation in patients with arterial hypertension, cardiovascular disease and diabetes mellitus, is considered one of the most important factors for a more severe infection in persons with concomitant pathology. In addition, the effects of PAS blockage with angiotensin converting enzyme inhibitors (ACE inhibitors) and angiotensin II receptor blockers (ARBs) remains one of the most discussed topics in the literature on COVID-19. This review presents the data on the interaction between the virus and the main components of RAS and the factors influencing their expression level, the impact of ACE ­inhibitors and ARBs therapy on the disease outcome, and presents the perspectives of the treatment with recombinant ACE 2
In silico analysis of the contribution of cardiomyocyte-fibroblast electromechanical interaction to the arrhythmia
Although fibroblasts are about 5–10 times smaller than cardiomyocytes, their number in the ventricle is about twice that of cardiomyocytes. The high density of fibroblasts in myocardial tissue leads to a noticeable effect of their electromechanical interaction with cardiomyocytes on the electrical and mechanical functions of the latter. Our work focuses on the analysis of the mechanisms of spontaneous electrical and mechanical activity of the fibroblast-coupled cardiomyocyte during its calcium overload, which occurs in a variety of pathologies, including acute ischemia. For this study, we developed a mathematical model of the electromechanical interaction between cardiomyocyte and fibroblasts and used it to simulate the impact of overloading cardiomyocytes. In contrast to modeling only the electrical interaction between cardiomyocyte and fibroblasts, the following new features emerge in simulations with the model that accounts for both electrical and mechanical coupling and mechano-electrical feedback loops in the interacting cells. First, the activity of mechanosensitive ion channels in the coupled fibroblasts depolarizes their resting potential. Second, this additional depolarization increases the resting potential of the coupled myocyte, thus augmenting its susceptibility to triggered activity. The triggered activity associated with the cardiomyocyte calcium overload manifests itself in the model either as early afterdepolarizations or as extrasystoles, i.e., extra action potentials and extra contractions. Analysis of the model simulations showed that mechanics contribute significantly to the proarrhythmic effects in the cardiomyocyte overloaded with calcium and coupled with fibroblasts, and that mechano-electrical feedback loops in both the cardiomyocyte and fibroblasts play a key role in this phenomenon. Copyright © 2023 Kursanov, Balakina-Vikulova, Solovyova, Panfilov and Katsnelson.Russian Science Foundation, RSF: 21-14-00226The study was supported by the Russian Science Foundation grant No. 21-14-00226
- …
