On the chromatic numbers of 3-dimensional slices

We prove that for an arbitrary $\varepsilon > 0$ holds $$\chi (\mathbb{R}^3 \times [0,\varepsilon]^6) \geq 10,$$ where $\chi(M)$ stands for the chromatic number of an (infinite) graph with the vertex set $M$ and the edge set consists of pairs of monochromatic points at the distance 1 apart

The experience of radiofrequency ablation of atrial tachycardia focus with the use of high-density myocardial mapping

The article presents a case of successful treatment of focal atrial tachycardia by radiofrequency ablation using high-density myocardial mapping. The aim of the work was to evaluate the possibilities of high-resolution myocardial mapping by EnsitePrecision® navigation system in the treatment of complex arrhythmias. The analysis of clinical data and results of electrophysiological examination of a 29-year-old patient with continuous recurrent focal atrial tachycardia was carried out. The patient was admitted with complaints of heart rate disorders and frequent short attacks of palpitations. According to electrocardiography, frequent short paroxysms of focal atrial tachycardia were revealed. The patient was taken for electrophysiological examination and radiofrequency ablation of the focus of atrial tachycardia. The focus of atrial tachycardia was located in the anterior septal part of the left atrium, which is a rare localization. After radiofrequency ablation tachycardia was terminated, no complications and recurrences were registered. The patient was discharged with the sinus rhythm. Navigation system EnsitePrecision® enables conducting high-density myocardial mapping, which helps to accurately determine the localization of the source of tachycardia. The radiation load on the patient and ablation time are reduced, which reduces the frequency of complications from the procedure

Production of Bst polymerase for diagnosis of different infections using loop-mediated isothermal amplification

Introduction. The large fragment of DNA polymerase I from Geobacillus stearothermophilus GIM1.543 (Bst DNA polymerase) possesses 5'-3' DNA polymerase activity, 5'-3' displacement activity and high processivity. These properties make it possible to use Bst DNA polymerase in loop-mediated isothermal amplification (LAMP), which provides highly specific amplification of the target sequence and is used for rapid detection of agents causing human infectious diseases. The purpose of the study was to produce a recombinant Bst polymerase enzyme in the bacterial expression system and to assess its properties for LAMP-based diagnostics of infectious diseases. Materials and methods. Expression constructs carrying the Bst polymerase gene were obtained using genetic engineering techniques. Different Escherichia coli strains were used for protein expression. Metal-chelate and gel filtration chromatography techniques were used for protein purification. Catalytic characteristics of the enzyme were assessed in loop-mediated isothermal amplification reactions using AmpliSens SARS-CoV-2-IT, AmpliSens IAV-IT and AmpliSens IBV-IT diagnostic systems designed for high-quality detection of SARS-CoV-2, influenza A virus (IAV) and influenza B virus (IBV) RNA, respectively. Results. The offered protocol for production, extraction and purification of recombinant Bst polymerase makes it possible to produce the enzyme in the bacterial expression system using E. coli cells in a soluble form and reaching the yield up to 20% of the total cell mass. In LAMP reactions, the obtained enzyme demonstrates activity comparable with that of the commercial enzyme Bst 2.0 (NEB). Conclusion. Considering the fast purification and production of the enzyme, the obtained recombinant Bst polymerase can be used in LAMP-based diagnostic kits

Empagliflozin in patients hospitalized for acute decompensated heart failure: an expert resolution on the discussion of the EMPULSE trial

An online expert meeting held on November 17, 2021 reviewed the results of the randomized, double-blind, multinational, parallel-group EMPULSE trial, evaluating the clinical benefit and safety of the sodium-glucose co-transporter-2 inhibitor (SGLT2i) empagliflozin compared with placebo in patients hospitalized with acute decompensated heart failure (ADHF). Patients were included in the study regardless of ejection fraction (EF) and the presence of diabetes and randomized during hospitalization after stabilization. In addition, the EMPULSE trial used a composite result analyzed using a stratified benefit ratio — Win Ratio analysis. There is evidence of clinical benefit of empagliflozin in hospitalized patients with preserved and reduced LVEF, as well as in patients with newly diagnosed ADHF or with acute decompensation of chronic heart failure (CHF) compared with placebo, regardless of type 2 diabetes presence. The importance of the favorable results of the EMPULSE trial and its significance for clinical practice, which implies the early administration of empagliflozin for inpatients, is noted. A number of proposals have been adopted to accelerate the introduction of empagliflozin into clinical practice for patients with ADHF

Calcium antagonists: from history of creation to modern clinical practice

The article discusses the problem of using calcium antagonists in clinical practice. Taking into account the current guidelines, the place of calcium antagonists in the treatment of major cardiovascular diseases was defined: hypertension, coronary artery disease, supraventricular arrhythmias, etc. Clinical trials are described which provided the evidence base for the use of calcium antagonists. The feasibility of long-acting calcium channel blockers which represent an optimum combination of efficiency and safety is emphasized. The results of clinical trials evaluating the efficacy of diltiazem for the treatment of patients with cardiovascular diseases are discussed

CARDIOCYTOPROTECTION PERSPECTIVES WITH ISCHEMIC PRECONDITIONING: HYPOXIA-INDUCED FACTOR 1 — POSSIBLE MOLECULAR MECHANISM AND TARGET FOR PHARMACOTHERAPY

The article is focused on the analysis of modern fundamental studies of the preconditioning/preintervention phenomenon in coronary heart disease and heart failure. Brief prerequisites are given for the phenomenon assessment. Molecular and genetic base of the phenomenon presented, as the results of modern experimental works in the area of fundamental medicine and clinical observations of the patients with various cardiovascular diseases. Hypoxia-induced factor 1 — main pathogenetic adaptation factor for hypoxia — plays critical protection role in pathophysiology of coronary heart disease and heart failure, controlling and determining the supply and utilization of oxygen, regulating angiogenesis and vascular remodelling, glucose metabolism and redox exchange. Personalized medicine technology, based on the pharmacogenomics, pharmacoproteomics, makes it to implement fundamental discoveries in medicine to clinical practice