Plant thionins: structure, biological functions and potential use in biotechnology

Antimicrobial peptides (AMPs) are important components of defense system in both plants and animals. They represent an ancient mechanism of innate immunity providing rapid first line of defense against pathogens. Plant AMPs are classified into several families: thionins, defensins, nonspecific lipid-transfer proteins, hevein- and knottin-type peptides, hairpinins and macrocyclic peptides (cyclotides). The review focuses on the thionin family. Thionins comprise a plant-specific AMP family that consists of short (~5 kDA) cysteine-rich peptides containing 6 or 8 cysteine residues with antimicrobial and toxic properties. Based on similarity in amino acid sequences and the arrangement of disulphide bonds, five structural classes of thionins are discriminated. The three-dimensional structures of a number of thionins were determined. The amphipathic thionin molecule resembles the Greek letter Г, in which the long arm is formed by two antiparallel α-helices, while the short one, by two parallel β-strands. The residues responsible for the antimicrobial activity of thionins were identified. Thionins are synthesized as precursor proteins consisting of a signal peptide, the mature peptide region and the C-terminal prodomain. Thionins protect plants from pathogenic bacteria and fungi acting directly on the membranes of microorganisms at micromolar concentrations, although their precise mode of action remains unclear. In addition to plant pathogens, thionins inhibit growth of a number of human pathogens and opportunistic microorganisms, such as Candida spp., Saccharomyces cerevisiae, Fusarium solani, Staphylococcus aureus and Escherichia coli. Thionins are toxic to different types of cells including mammalian cancer cell lines. Transgenic plants expressing thionin genes display enhanced resistance to pathogens. A wide range of biological activities makes thionins promising candidates for practical application in agriculture and medicine

Classification of Municipalities in the Republic of Buryatia by the Level of Tick-Borne Viral Encephalitis Incidence

Tick-borne viral encephalitis (TBVE) is one of the most significant natural-focal infections in the Russian Federation.The aim of the study was to analyze the current epidemiological situation on TBVE in the Buryat Republic in 2010–2020 with a subsequent differentiation of municipalities by epidemiological risk groups in order to elaborate proposals for optimization of preventive measures.Materials and methods. A retrospective analysis of the epidemiological situation on TBVE in the Buryat Republic was carried out using forms of federal statistical surveillance No. 2 “Information on infectious and parasitic diseases” over 2010–2020 and the data from the Reference Center of the Irkutsk Research Anti-Plague Institute of Siberia and Far East of the Rospotrebnadzor on the epidemiological situation and preventive measures in the municipalities of the constituent entity. Statistical processing was performed applying conventional methods of variation statistics. Based on calculated 95 % parametric confidence interval for the data on variability of the long-term average TBVE incidence in the municipalities of the Republic of Buryatia over a 10-year period, the entities were differentiated by epidemiological risk groups. QGis 2.18.28 and a set of open geodata OpenStreetMap were used for mapping.Results and discussion. All municipalities have been classified into five groups by the level of epidemiological risk: with zero TBVE incidence – 2 districts, with a low level – 4, medium – 8, high – 5, very high – 2. In addition, the administrative center has been placed into a separate group. Each individual group of municipalities is characterized by the number of TBVE cases, the level of morbidity, the frequency of seeking medical aid because of tick bites, the scope of specific and non-specific prevention measures. Recommendations for optimizing the tactics of TBVE prevention in certain municipal districts have been provided

EFFICACY AND SAFETY OF SINUS RHYTHM RESTORATION WITH AMIODARONE AND PROPAFENONE IN OUTPATIENTS, ECONOMIC ASPECTS (BASED ON DATA OF N.A. SEMASHKO NORTHERN MEDICAL CLINICAL CENTER)

Aim. To study efficacy and safey of sinus rhythm restoration with amiodarone and propafenone in outpatients with recurrent atrial fibrillation (AF), and to estimate pharmacoeconomic efficiency of such cardioversion in comparison with hospital treatment.Material and methods. Patients (n=199; aged 59.2±1.36) with paroxysmal (73.9%) or persistent (26.1%) AF were included into the multicenter prospective study. Follow-up period was 13.14 months (min 1 month, max 36 months). Patients with arrhythmia relapse <48 h received outpatient cardioversion with amiodarone or propafenone orally. Daily outpatient examination, including ECG and blood pressure monitoring every 30-60 min, was carried out to evaluate efficacy of cardioversion and hemodynamics. Phone contact with patients was available. Patients with unstable hemodynamics received cardioversion in hospital. Patients received propafenone in cumulative dose of 600 mg (150-300 mg every hour), and amiodarone 600-800 mg daily. The cost/effectiveness ratio (CER) was estimated. This ratio shows the cost of one unit of effect.Results. Outpatient cardioversion with amiodarone was started 24 h earlier (p=0.029) and with propafenone — 4.5 h earlier (p=0.002) than that in hospital. The average dose of amiodarone in ambulatory cardioversion was 1.3 times less (713.7±84,62 mg, p=0.345) than that in hospital cardioversion. Outpatient treatment with amiodarone restored sinus rhythm 8.7 h earlier, and with propafenone - 3.5 h earlier than the same treatments in hospital. Efficiency of hospital cardioversion with amiodarone was 70%, with propafenone - 80%, and efficiency of outpatient cardioversion — 96,1% and 98,4%, respectively. Outpatient treatment did not cause any severe side effects. Expenses for outpatient cardioversion made up 143 724.25 rubles, and for hospital cardioversion — 92 870.47 rubles. Average treatment costs for one patient in hospital was 6 times greater than for an outpatient. Outpatient cardioversion had the lowest CER (~1300 rubles%).Conclusion. Outpatient cardioversion with amiodarone or propafenone is not only effective and safe, but also economically feasible

Распространенность и клиническое значение нарушений дыхания, вызванных обструкцией верхних дыхательных путей во время сна, у пациентов с нарушениями сердечного ритма

Cardiac arrhythmias and respiratory disorders caused by upper airway obstruction during sleep are quite common pathologies. Fifty two patients with paroxysmal atrial fibrillation and frequent ventricular extrasystoles were examined in order to evaluate the spreading of sleep respiratory disorders and their role for arrhythmias pathogenesis.The obtained results revealed the high frequency of respiratory disorders in arrhithmias patients and the relationship between circadian arrhithmias character and the intensity of sleep respiratory disorders. Comparative analyse of the SPAP-therapy and the anti-arrhithmic medication effect on SOAHS showed more high efficacy of the first one.Аритмии сердца и нарушения дыхания, вызванные обструкцией верхних дыхательных путей во время сна, являются весьма распространенным патологическим состоянием. С целью оценки распространенности нарушений дыхания во время сна и их роли в патогенезе аритмий были исследованы 52 пациента с пароксизмальной мерцательной аритмией и частой желудочковой экстрасистолией.По результатам исследования выявлена высокая распространенность нарушений дыхания в группе больных с аритмиями, а также наличие определенной взаимосвязи циркадного характера аритмий с выраженностью нарушений дыхания во время сна. Сравнительный анализ антиаритмического эффекта медикаментозной терапии СОАГС и СРАР-терапии показал более высокую эффективность последней

To the issue of population structure of Convallaria majalis L. and Polygonatum multiflorum L. in the “Bitsevsky forest” natural and historical park

The authors of this article conducted a study of the population structure of Convallaria majalis L. and Polygonatum multiflorum (L.) All. flowered relating to protected species and included in the Red book of Moscow and Moscow region. For the first time in the Bitsa forest Park based on the characteristics of stages of ontomorphogenesis of the investigated species described and analyzed the age structure of their populations

Influence of Interfacial Adhesion and the Nonequilibrium Glassy Structure of a Polymer on the Enthalpy of Mixing of Polystyrene-Based Filled Composites

For composites based on polystyrene, the styrene-butadiene copolymer, and polybutadiene filled with various kinds of zinc oxide powder, the enthalpy of mixing is calculated in the entire range of filler contents on the basis of calorimetric measurements with the use of the thermochemical cycle. It is shown that, when the polymer is in excess in the composites based on polystyrene and its copolymer, the enthalpy of mixing is negative, whereas at a high content of the filler, this value is positive. The alternating-sign pattern of the concentration dependence of the enthalpy of mixing is interpreted in terms of the superposition of the negative contribution of the enthalpy of the interfacial-adhesion interaction of a polymer matrix with the filler and the positive contribution due to a gain in the level of nonequilibrium of the glassy matrix near the surface. A thermodynamic model that makes it possible to separate these contributions and to describe the experimental curves of the enthalpy of mixing for the composites is advanced. © Pleiades Publishing, Ltd., 2012

Swelling and contraction of ferrogels based on polyacrylamide in a magnetic field

The equilibrium swelling of magnetoactive ferrogels based on the copolymer of acrylamide with 10% potassium acrylate in water is studied. The gels are filled with strontium ferrite and/or magnetite taken in amounts of 20, 40, 60, and 80 parts per 100 parts of the polymer by weight. In the absence of a magnetic field, as the content of the filler is increased, the degree of swelling tends to increase for the gels containing strontium ferrite and to decrease for the magnetite-containing gels. In the structure of hydrogels, strontium ferrite particles possessing a permanent magnetic moment form a microscopic network from chain aggregates, while the particles of magnetite, a magnetically soft material, give rise to disordered aggregates. The enthalpy of hydration of ferrogel polymeric matrices weakly depends on the nature and amount of the introduced filler: The interaction parameter takes small positive values in the range 0.10-0.18. In a homogeneous magnetic field of 365 mT, the degree of swelling decreases at a small filler content for both types of ferrogels. This effect is accompanied by elongation of a ferrogel sample along the field direction and contraction in the transverse direction. With an increase in the filler content, the inversion of both effects occurs. The applicability of concepts about the homogeneously magnetizable continuous medium to the process of magnetostriction of ferrogels is analyzed. © Pleiades Publishing, Ltd., 2012

Botox’s Place in the Complex Treatment of Oculomotor System Pathology (the Optimal “Portrait” of the Patient for the Chemodenervation)

Introduction. To summarize our fifteen-years clinical experience of using Botox in strabismology and determine the indications for the most effective use of chemodenervation in the complex treatment of oculomotor system pathology.Patients and methods. To carry out chemodenervation of extraocular muscles, Botox was used. The optimal dose of Botox for intramuscular injection ranged from 1.25 to 5.0 units. The choice of dosage depends on the patient’s age, the type oculomotor system pathology, the level of muscular dysfunction and the purpose of the treatment. The treatment was performed in 376 patients with various disorders of oculomotor system. At the time of treatment, the patients’ ages ranged from 12 to 78 years. Injection of Botox into the extraocular muscles in all cases was the primary method of treatment.Results. In general, the state of relative functional recovery was achieved in 71.81% of cases (in 270 patients). The best results were obtained in treatment of decompensated heterophories, acute heterotrophies, atypical heterotrophies and primary hyperfunction of the inferior oblique muscles (in 100% of cases). In these conditions, the binocular vision was preserved in patients, and the imbalance of the oculomotor system did not show any sign of incomitance. However, patients with paralysis and paresis of the cranial nerves chemodenervation allowed creating conditions for a more complete restoration of muscular functions, to avoid the occurrence of a secondary imbalance in the oculomotor system. In 70.3% cases (185 patients), subsequent surgical treatment was not required. Reliable functional results of treatment allowed creating the optimal algorithm for chemodenervation.Discussion. Chemodenervation of extraocular muscles is an effective independent and additional method of complex treatment of oculomotor system pathology and expands opportunities in patients’ rehabilitation. To achieve maximum functional results, it is necessary to select patients correctly for this procedure, taking into account its appropriateness and advantages over alternative methods of treatment, selection of optimal dosages of Botox