METHOD OF MEASURING THE CONTRACTILE ACTIVITY OF THE HEART MUSCLE

We described the methods for measuring and evaluating the contractile activity of the cardiac muscle under dynamic change in length. These methods allow us to determine the contractile potential of the muscle on the basis of it is behavior under given mechanical conditions

Towards sustainable development through bridging digital penetration gaps

The aim of the article is to study the impact of the digital environment on the economic conditions of economic entities, as well as to assess the gaps between economic development, changes in social relations and environmental well-being. It is proved that gaps in digital penetration can cause the deepening of existing inequalities and risks: digital inequality, social inequality, inequality in the appropriation of benefits, environmental risks. Approaches to assessing the impact of digital artifacts on the environment (in the context of the concept of "circular economy") and sustainable development of the economic system are investigate

DEVELOPMENT OF METHOD FOR ANALYSIS OF THE T-TUBULAR SYSTEM IN RAT CARDIOMYOCYTES

The t-system is the highly structured network of membrane invaginations playing an im-portant role in the regulation of cardiac electromechanical coupling and contraction. We de-signed an approach to evaluate the structure of the cardiomyocyte t-tubular system in detail.При поддержке гос.задания ИИФ УрО РАН (тема № AAAA-A19-119070190064-4)

Type 1 Diabetes Impairs Cardiomyocyte Contractility in the Left and Right Ventricular Free Walls but Preserves It in the Interventricular Septum

Type 1 diabetes (T1D) leads to ischemic heart disease and diabetic cardiomyopathy. We tested the hypothesis that T1D differently affects the contractile function of the left and right ventricular free walls (LV, RV) and the interventricular septum (IS) using a rat model of alloxan-induced T1D. Single-myocyte mechanics and cytosolic Ca2+ concentration transients were studied on cardiomyocytes (CM) from LV, RV, and IS in the absence and presence of mechanical load. In addition, we analyzed the phosphorylation level of sarcomeric proteins and the characteristics of the actin-myosin interaction. T1D similarly affected the characteristics of actin-myosin interaction in all studied regions, decreasing the sliding velocity of native thin filaments over myosin in an in vitro motility assay and its Ca2+ sensitivity. A decrease in the thin-filament velocity was associated with increased expression of β-myosin heavy-chain isoform. However, changes in the mechanical function of single ventricular CM induced by T1D were different. T1D depressed the contractility of CM from LV and RV; it decreased the auxotonic tension amplitude and the slope of the active tension-length relationship. Nevertheless, the contractile function of CM from IS was principally preserved. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This work was supported by the Russian Science Foundation № 18-74-10059. The work was performed using the equipment of the Shared Research Center of Scientific Equipment of Institute of Immunology and Physiology

Effectiveness of intravenous isoniazid and ethambutol administration in patients with tuberculosis meningoencephalitis and HIV infection

Effectiveness of intravenous isoniazid and ethambutol administration in patients with tuberculosis meningoencephalitis and HIV infection / Dmytro Butov, Yurii Feshchenko, Mykhailo Kuzhko, Mykola Gumenuik, Kateryna Yurko, Alina Grygorova, Anton Tkachenko, Natalia Nekrasova, Tetiana Tlustova, Vasyl Kikinchuk, Alexandr Peshenko, Tetiana Butova // Tuberculosis and Respiratory Diseases. – 2019. – № 82. – Р. 1-8. – DOI: https://doi.org/10.4046/trd.2019.0021Метою даного дослідження було вивчення ефективності внутрішньовенного введення ізоніазиду (І) та етамбутолу (Е) у пацієнтів з лікарсько-чутливим туберкульозом легень (ТЛ) з позитивним результатом мокротиння, туберкульозним менінгоенцефалітом (ТМ) та вірусом імунодефіциту людини (ВІЛ) у інтенсивній фазі лікеування. При ТЛ/ТМ з ВІЛ внутрішньовенне лікування І та Е було більш ефективним, ніж пероральне лікування І та Е, через 2 місяці інтенсивного лікування в конверсії мокротиння, а також у клінічному поліпшенні, що супроводжується значно вищими середніми концентраціями у сироватці. Крім того, рівень смертності був нижчим при внутрішньовенному лікуванні І та Е порівняно з пероральним лікуванням.The aim of this study was to investigate the effectiveness of intravenous isoniazid (H) and ethambutol (E) administered in patients with new sputum positive drug-susceptible pulmonary tuberculosis (TB) with tuberculous meningoencephalitis (TM) and human immunodeficiency virus (HIV) co-infection in the intensive phase of treatment. In TB/TM with HIV, the intravenous H and E treatment was more effective than oral H and E treatment at 2 months of intensive treatment in sputum conversion as well as in clinical improvement, accompanied by significantly higher mean serum concentrations. In addition, the mortality rate was lower in intravenous H and E treatment compared to oral treatment.Целью данного исследования было изучение эффективности внутривенного введения изониазида (И) и этамбутола (Э) у пациентов с лекарственно-чувствительным туберкулезом легких (ТЛ) с положительным результатом мокроты, туберкулезным менингоэнцефалитом (ТМ) и вирусом иммунодефицита человека (ВИЧ) в интенсивной фазе лечения. При ТЛ/ТМ с ВИЧ внутривенное лечение И и Э было более эффективным, чем пероральное лечение И и Э, через 2 месяца интенсивного лечения в конверсии мокроты, а также в клиническом улучшении, сопровождаемом значительно более высокими средними концентрациями в сыворотке. Кроме того, уровень смертности был ниже при внутривенном лечении И и Э по сравнению с пероральным лечением

Changes in rat myocardium contractility under subchronic intoxication with lead and cadmium salts administered alone or in combination

Subchronic intoxications induced in male rats by repeated intraperitoneal injections of lead acetate and cadmium chloride, administered either alone or in combination, are shown to affect the biochemical, cytological and morphometric parameters of blood, liver, heart and kidneys. The single twitch parameters of myocardial trabecular and papillary muscle preparations were measured in the isometric regime to identify changes in the heterometric (length-force) and chronoinotropic (frequency-force) contractility regulation systems. Differences in the responses of these systems in trabecules and papillary muscles to the above intoxications are shown. A number of myocardium mechanical characteristics changing in rats under the effect of a combined lead-cadmium intoxication and increased proportion of α-myosin heavy chains were observed to normalize fully or partially if such intoxication was induced against background administration of a proposed bioprotective complex. Based on the experimental results and literature data, some assumptions are suggested concerning the mechanisms of the cardiotoxic effects produced by lead and cadmium. © 2020AAAA-A18-118020590031-8, AAAA-A18-118020590031The work was carried out partly within the framework of the IIF UrB RAS theme No AAAA-A18-118020590031-8 and AAAA-A18-118020590031. This work was performed using the equipment of the Shared Research Center of Scientific Equipment SRC IIP UrB RAS

Cardioinotropic effects in subchronic intoxication of rats with lead and/or cadmium oxide nanoparticles

Subchronic intoxication was induced in outbred male rats by repeated intraperitoneal injections with lead oxide (PbO) and/or cadmium oxide (CdO) nanoparticles (NPs) 3 times a week during 6 weeks for the purpose of examining its effects on the contractile characteristics of isolated right ventricle trabeculae and papillary muscles in isometric and afterload contractions. Isolated and combined intoxication with these NPs was observed to reduce the mechanical work produced by both types of myocardial preparation. Using the in vitro motility assay, we showed that the sliding velocity of regulated thin filaments drops under both isolated and combined intoxication with CdO– NP and PbO–NP. These results correlate with a shift in the expression of myosin heavy chain (MHC) isoforms towards slowly cycling β–MHC. The type of CdO–NP + PbO–NP combined cardiotoxicity depends on the effect of the toxic impact, the extent of this effect, the ratio of toxicant doses, and the degree of stretching of cardiomyocytes and muscle type studied. Some indices of combined Pb–NP and CdO–NP cardiotoxicity and general toxicity (genotoxicity included) became fully or partly normalized if intoxication developed against background administration of a bioprotective complex. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The work was carried out partly within the framework of the IIF UrB RAS themes No AAA?A18?118020590031?8 and AAAA?A18?118020590135?3. This work was performed using the equipment of the Shared Research Center of Scientific Equipment SRC IIP UrB RAS