Репозиторий Университета

© 2020 by the authors. The success of using soft tissue transplants is enough for their spreading in the clinic, but the need to cover the surface, where the transplant was taken from, can be forgotten. It can lead to long-term discomfort of the patient in real life, in some cases to complications alike bleeding; We performed the analysis of the use of different new xenogenic resorbable membranes created within our University in compare with the natural healing of oral mucosa defects in the experiment in vivo on 36 rabbits after performing of the surgical wound on the palatine side (5x5 mm). All animals were separated (divided) for 3 groups: #1 group of control and main groups #2 and #3, where we used pericardium and collagen film for covering mucous defects. We assessed the edema, hyperemia in the operation side, the pain according to animal behavior, the histological picture after animals completion of the experiment (on 3rd, 6th and 10th days); The decrease of clinical signs of inflammation in groups of collagen and pericardium films use (p<0.05) was statistically confirmed. Analysis of histologic investigation of biopsy specimens has shown the faster and massive growth of soft tissue in the donor site after application of pericardium and collagen films (p<0.05). An analysis of the experiment results allows recommending their possible use for closing the donor site after taking a free gingival graft or in the zone of postoperative wound defect in the oral mucosa in clinical oral surgery after specific clinical trials.

© 2020 Elsevier B.V. Telomerase activity has been demonstrated in a wide variety of most solid tumors and considered as a well-known cancer biomarker. The commonly utilized method for its detection is polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (TRAP). However, the TRAP technique suffers from false-negative results caused by the failure of PCR step. Moreover, it requires advanced equipment with a tedious and time-consuming procedure. Herein, we presented a portable nitrocellulose paper-based nanobiosensing platform for ultrafast and equipment-free detection of telomerase activity based on a simple colorimetric assay that enabled naked-eye visualization of the color change in response to enzyme activity. In this platform, hybridization was initially performed between telomere complementary oligonucleotide immobilized on gold nanoparticles (GNPs) and telomerase elongated biotinylated probe. Thereafter, the assembly was attached on activated paper strip via avidin-biotin interaction. The signal amplification was carried out by enlargement of the attached GNPs on the paper strip, forming tightly compact rod-shaped submicron structures of gold representing a visual color formation. Thanks to significant sensitivity enhancement, the color change was occurred for down to 6 cells, which can be easily observed by the naked eye. Due to the desired aspects of the developed assay including PCR-free, low cost, simple, and high sensitivity, it can be used for evaluation of telomerase activity in cell extracts for future clinical applications. Furthermore, this design has the ability to be easily integrated into lab-on-chip devices for point-of-care telomerase sensing.

© 2020 Elsevier B.V. Herein four modified polymers were prepared from readily available addition poly(5-vinyl-2-norbornene) (PVNB) and their gas-transport properties were studied in detail. Hydrogenation, epoxidation, cyclopropanation and thiol-en reactions were chosen for the modifications of PVNB. Hydrogenation of PVNB was performed using p-toluenesulfonyl hydrazide. Epoxidation of PVNB was realized employing m-chloroperoxybenzoic acid. Cyclopropanation of PVNB was carried out using diazomethane in the presence of a Pd-catalyst. For thiol-en reaction, thioacetic acid was applied as the source of a thiol and AIBN as an initiator. All listed modifications were performed in high yields (≥80%) without the destruction of polymer main chains. The degree of functionalizations was up to 99%. The influence of these modifications on the properties of the resulting polymers was evaluated. Cyclopropanation and hydrogenation of PVNB led to an enhancement of gas permeability with minimal decrease in selectivity, while epoxidation or thioacetylation gave a substantial increase in CO2/N2 selectivity with decrease in permeability. The modified polymers with polar side-groups exhibited attractive selectivities for CO2/N2, CO2/CH4 and H2/N2 gas separations.

© 2019 Elsevier B.V. and Mitochondria Research Society Mitochondria have been widely accepted as the main source of ATP in the cell. The inner mitochondrial membrane (IMM) is important for the maintenance of ATP production and other functions of mitochondria. The electron transport chain (ETC) generates an electrochemical gradient of protons known as the proton-motive force across the IMM and thus produces the mitochondrial membrane potential that is critical to ATP synthesis. One of the main factors regulating the structural and functional integrity of the IMM is the changes in the matrix volume. Mild (reversible) swelling regulates mitochondrial metabolism and function; however, excessive (irreversible) swelling causes mitochondrial dysfunction and cell death. The central mechanism of mitochondrial swelling includes the opening of non-selective channels known as permeability transition pores (PTPs) in the IMM by high mitochondrial Ca2+ and reactive oxygen species (ROS). The mechanisms of reversible and irreversible mitochondrial swelling and transition between these two states are still unknown. The present study elucidates an upgraded biophysical model of reversible and irreversible mitochondrial swelling dynamics. The model provides a description of the PTP regulation dynamics using an additional differential equation. The rigidity tensor was used in numerical simulations of the mitochondrial parameter dynamics with different initial conditions defined by Ca2+ concentration in the sarco/endoplasmic reticulum. We were able to estimate the values of the IMM rigidity tensor components by fitting the model to the previously reported experimental data. Overall, the model provides a better description of the reversible and irreversible mitochondrial swelling dynamics.

© 2019 Elsevier B.V. Submicrocapsules were prepared from diethylaminoethyl dextran (DEAE-D), xanthan gum (XG) and bovine serum albumin (BSA) on oil cores by ultrasonic treatment. These capsules were modified with poly-L-lysine (PLL) via electrostatic adsorption. The behavior of the capsules was investigated at an air–water interface after their introduction into an aqueous subphase. The interaction of the capsules with 1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) monolayer formed on the water surface (model cellular membrane) was studied both upon their introduction under the condensed monolayer and with the use of a dilute colloidal solution of the capsules as a subphase. Biodegradation of the proteinaceous capsules with subsequent oil-core release was demonstrated by influence of pronase. The Langmuir lipid monolayer was found to be a good model for investigation of drug release from the capsules in the presence of the cellular membrane.

© 2019 by the authors. This paper reveals the mechanism of nanowelding a branched network of single-walled carbon nanotubes (SWCNTs) used as a framework for the formation of protein-polymer matrices with albumin, collagen, and chitosan. It is shown that the introduction of certain point defects into the structure of SWCNTs (single vacancy, double vacancy, Stone-Wales defect, and a mixed defect) allows us to obtain strong heating in defective regions as compared to ideal SWCNTs. The wavelengths at which absorption reaches 50% are determined. Non-uniform absorption of laser radiation along with inefficient heat removal in defective regions determines the formation of hot spots, in which nanowelding of SWCNTs is observed even at 0.36 nm between contacting surfaces. The regularities of formation of layered protein-polymer matrices and the features of their interaction with cell membrane are revealed. All studies are carried out in silico using high-precision quantum approaches.

© 2019 WILEY-VCH Verlag GmbH  &  Co. KGaA, Weinheim Nanoporous glassy polymers are perspective materials for the fabrication of gas separation membranes, especially for the application of gaseous hydrocarbon separation. However, the drawback of such materials is the pronounced physical aging resulting in the dramatic drop of gas transport properties due to relaxation of high-free-volume fraction in time. Herein, a novel and readily available group of such glassy polymers is reported based on 5-alkylnorbornenes. These polymers are easily synthesized from dicyclopentadiene and α-olefins by Diels-Alder reaction and vinyl (addition) polymerization of the formed cycloadducts in the presence of ([(η3-C3H5)PdCl]2/PCy3/Na+[B(3,5-(CF3)2C6H3)4]− catalyst. The obtained polymers display low-fraction free volume, stable gas permeability over time, and possess a unique feature for the glassy polymers—solubility controlled permeation of hydrocarbons and enhanced C4H10/CH4 selectivity.

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Sterols change the biophysical properties of lipid membranes. Here, we analyzed how sterols affect the activity of widely used antimicrobial membrane-active compounds, sodium dodecyl sulfate (SDS) and benzalkonium chloride (BAC). We also tested a novel benzalkonium-like substance, Kor105. Our data suggest that benzalkonium and Kor105 disturb the ordering of the membrane lipid packaging, and this disturbance is dampened by cholesterol. The disturbance induced by Kor105 is stronger than that induced by BAC because of the higher rigidity of the Kor105 molecule due to a shorter linker between the phenyl group and quaternary nitrogen. On the contrary, individual SDS molecules do not cause the disturbance. Thus, in the tested range of concentrations, SDS-membrane interaction is not influenced by cholesterol. To study how sterols influence the biological effects of these chemicals, we used yeast strains lacking Lam1-4 proteins. These proteins transport sterols from the plasma membrane into the endoplasmic reticulum. We found that the mutants are resistant to BAC and Kor105 but hypersensitive to SDS. Together, our findings show that sterols influence the interaction of SDS versus benzalkonium chloride and Kor105 with the membranes in a completely different manner.

© 2017 The mitochondrial membrane potential (ΔΨm) generated by proton pumps (Complexes I, III and IV) is an essential component in the process of energy storage during oxidative phosphorylation. Together with the proton gradient (ΔpH), ΔΨm forms the transmembrane potential of hydrogen ions which is harnessed to make ATP. The levels of ΔΨm and ATP in the cell are kept relatively stable although there are limited fluctuations of both these factors that can occur reflecting normal physiological activity. However, sustained changes in both factors may be deleterious. A long-lasting drop or rise of ΔΨm vs normal levels may induce unwanted loss of cell viability and be a cause of various pathologies. Among other factors, ΔΨm plays a key role in mitochondrial homeostasis through selective elimination of dysfunctional mitochondria. It is also a driving force for transport of ions (other than H+) and proteins which are necessary for healthy mitochondrial functioning. We propose additional potential mechanisms for which ΔΨm is essential for maintenance of cellular health and viability and provide recommendations how to accurately measure ΔΨm in a cell and discuss potential sources of artifacts.

© 2018 Elsevier Ltd  Rod cell membranes contain cholesterol-rich detergent-resistant membrane (DRM) rafts, which accumulate visual cascade proteins as well as proteins involved in regulation of phototransduction such as rhodopsin kinase and guanylate cyclases. Caveolin-1 is the major integral component of DRMs, possessing scaffolding and regulatory activities towards various signaling proteins. In this study, photoreceptor Ca 2+ -binding proteins recoverin, NCS1, GCAP1, and GCAP2, belonging to neuronal calcium sensor (NCS) family, were recognized as novel caveolin-1 interacting partners. All four NCS proteins co-fractionate with caveolin-1 in DRMs, isolated from illuminated bovine rod outer segments. According to pull-down assay, surface plasmon resonance spectroscopy and isothermal titration calorimetry data, they are capable of high-affinity binding to either N-terminal fragment of caveolin-1 (1–101), or its short scaffolding domain (81–101) via a novel structural site. In recoverin this site is localized in C-terminal domain in proximity to the third EF-hand motif and composed of aromatic amino acids conserved among NCS proteins. Remarkably, the binding of NCS proteins to caveolin-1 occurs only in the absence of calcium, which is in agreement with higher accessibility of the caveolin-1 binding site in their Ca 2+ -free forms. Consistently, the presence of caveolin-1 produces no effect on regulatory activity of Ca 2+ -saturated recoverin or NCS1 towards rhodopsin kinase, but upregulates GCAP2, which potentiates guanylate cyclase activity being in Ca 2+ -free conformation. In addition, the interaction with caveolin-1 decreases cooperativity and augments affinity of Ca2 + binding to recoverin apparently by facilitating exposure of its myristoyl group. We suggest that at low calcium NCS proteins are compartmentalized in photoreceptor rafts via binding to caveolin-1, which may enhance their activity or ensure their faster responses on Ca 2+ -signals thereby maintaining efficient phototransduction recovery and light adaptation.

© 2018 Dynasty Publishing House. All rights reserved. The review deals with specificities of interactions between decidual cells and cells of the maternal immune system. Literature data about involvement of decidual cells in initiation of the immune process are presented. The role of decidual cells in the formation of immunological tolerance due to variously secreted and expressed cytokine molecules that control sequential reproductive events has been shown. In the decidual membrane, complex interaction between decidual cells and cells of the maternal immune system occurs, aimed at ensuring immunological tolerance of the «mother-fetus» system. Impairment of this process leads to the development of gestational complications, including loss of a pregnancy.

The article describes a clinical case of Descemet's membrane detachment that occurred during cataract phacoemulsification with implantation of intraocular lens. Significant corneal edema developed in the early post-op period. Considering the ability of endothelium to close its own defects even with large injury area, the patient was followed-up for 2 years. Corneal edema was treated during 4 months and concluded with instillations of osmotic and anti-inflammatory drugs. At 1.5-2 months of therapy, the edema was gradually decreasing, and by the 4th month of the follow-up the cornea was practically transparent. Density of endothelial cells in central cornea, where the Descemet's membrane was absent, comprised 1000 cells/mm2. Further observation revealed cornea staying transparent for 2 years after the surgery. Complete optical recovery of patients with Descemet's membrane defect in this case study is supported by similar clinical cases briefly described in the article, and evidence that structural functional recovery of the corneal endothelial layer is possible even when it has large defects (more than 2.5 mm in diameter).

AIM: To develop predictive model for hepatic insufficiency in obstructive jaundice.MATERIAL AND METHODS: Obstructive jaundice was modeled by the author's method on 48 mini pigs, while morpho-functional features of erythrocytes were studied by using of INTEGRA Aura atomic force microscope (NT-MDT, Zelenograd, Russia). Histological specimens were stained with hematoxylin and eosin. Discriminant analysis was used to create predictive model for hepatic insufficiency.RESULTS: Mathematical model of hepatic insufficiency prediction has been developed. Sensitivity and specificity of this model were 94.1% and 74.2% respectively. Total percentage of correct predictions was 81.3%.CONCLUSION: Severe obstructive jaundice contributes erythrocyte's transformation from biconcave to dome-shaped followed by changes of its physical properties. Erythrocyte's volume and activity of cytolysis enzymes are the most informative to predict hepatic insufficiency. Our model allows us to diagnose this complication at early stages and to correct pre-, intra- and postoperative therapy.

© 2018 Media Sphera Publishing Group. All rights reserved. Goodpasture's disease (anti-GBM disease) is a rare small vessels vasculitis characterized by the presence of autoantibodies directed against the glomerular basement membrane (GBM) and alveolar basement membrane. Common feature of anti-GBM disease is a combination of rapidly progressive glomerulonephritis and alveolar hemorrhage (pulmonary-renal syndrome). We present a case of atypical disease course in a young male patient who developed alveolar hemorrhage without renal failure. The only symptom of renal involvement was isolated hematuria. Plasmapheresis combined with immunosuppression (cyclophosphamide and corticosteroids) was effective. We present a review of state-of-art data on the pathogenesis and disease course of anti-GBM disease.

© 2018, V.A. Negovsky Research Institute of General Reanimatology. All rights reserved.  Modifiers of membranes cause local defects on the cell surface. Measurement of the rigidity at the sites of local defects can provide further information about the structure of defects and mechanical properties of altered membranes. The purpose of the study: a step-by-step study of the process of a nonlinear deformation of red blood cells membranes under the effect of modifiers of different physico-chemical nature. Materials and methods. The membrane deformation of a viscoelastic composite erythrocyte construction inside a cell was studied by the atomic force spectroscopy. Nonlinear deformations formed under the effect of hemin, Zn 2+ ions, and verapamil were studied. Results. The process of elastic deformation of the membrane with the indentation of a probe at the sites of local defects caused by modifiers was demonstrated. The probe was inserted during the same step of the piezo scanner Δz displacement; the probe indentation occured at the different discrete values of Δh, which are the functions of the membrane structure. At the sites of domains, under the effect of the hemin, tension areas and plasticity areas appeared. A mathematical model of probe indentation at the site of membrane defects is presented. Conclusion. The molecular mechanisms of various types of nonlinear deformations occurring under the effect of toxins are discussed. The results of the study may be of interest both for fundamental researchers of the blood cell properties and for practical reanimatology and rehabilitology.

Репликативный полипротеин 1а вируса желтухи свеклы (ВЖС) содержит консервативные домены лидерной папаин-подобной протеиназы (РСР), метилтрансферазы (MTR) и РНК хеликазы (HEL). Центральный район (central region, CR) между MTR и HEL ранее считали «вариабельным». Нами проведен компьютерный анализ CR, который позволил выявить новый консервативный домен между позициями 1287-1390 (здесь и далее приводится нумерация аминокислотных остатков белка 1а вируса желтухи свеклы, BYV), сохраняющийся у всех представителей рода Closterovirus. Этот домен содержит 4 предсказанных альфа-спиральных участка (альфа А – D) и три строго консервативные позиции – глютамат-1291, пролин-1380 и аргинин-1384. Кроме того, биоинформатический анализ позволил предсказать амфипатическую спираль в позициях 1368-1380 (входящую в состав участка альфа D). Гидрофобный домен CR-2 (позиции 1305-1494 белка 1а), вызывающий при экспрессии в растениях реструктуризацию эндоплазматического ретикулюма и образование подвижных глобул диаметром ~1 мкм, включает участки альфа В, С и D. Установлено, что экспрессия в растениях слитных белков CR-2:GFP и GFP:CR-2 вызывает сходный «глобулообразующий» фенотип, т.е. N-концевое или C-концевое положение маркера GFP в слитном белке не влияет на переформатирование мембран эндоплазматического ретикулюма. Проведен делеционный анализ CR-2 BYV. Показано, что делеционные варианты 1355-1494 и 1325-1484 сохраняют фенотип дикого типа (образование глобул и реструктуризация ЭР вокруг ядра клетки). Варианты 1375-1484, 1368-1484 и 1368-1432 индуцировали образование глобул, но утрачивали способность к реструктуризации ЭР. Внесение замен гидрофобных аминокислотных остатков на остатки серина и глицина в «минимальном» делеционном мутанте 1368-1432 блокировало образование глобул. Предложена рабочая гипотеза о влиянии консервативной амфипатической спирали 1368-1385 в белке 1а BYV на ремоделирование мембран ЭР растительной клетки и создание репликативных платформ при клостеровирусной инфекции.

Цель работы - оценка состояния кортикального цитоскелета волокон камбаловидной мышцы крысы в результате 6-часового антиортостатического вывешивания на фоне предшествующего, в течение 3 сут по 100 мкг/сут, введения смеси фосфатидилхолинов (лецитина). Данные о периметре волокон, толщине подмембранного цитоскелета и доле разрывов в нем относительно периметра получали, используя иммуногистохимическую окраску на альфа-актинин-4. Периметр волокон оставался неизменным во всех группах исследования. При этом доля разрывов была выше в группах вывешивания, чем в соответствующих контрольных группах. Толщина окрашенного слоя, соответствующего подмембранному цитоскелету, не менялась в контрольных группах и в группе вывешивания без лецитина, однако в группе вывешивания на фоне лецитина она достоверно увеличивалась по сравнению с соответствующей контрольной группой на 27 % (p < 0,05) соответственно.

Purpose of the work was to assess the cortical cytoskeleton of m. soleus fibers from rats after 6-hr tail-suspension preceded by 3 days of phosphatidylcholine (lecithin) injections at a dose of 100 µг/d. Data about the fiber perimeter, submembrane cytoskeleton thickness and percentage of bonds breaks along the perimeter were obtained using the alpha-actinin-4 anti-body stain. The fiber perimeter remained unchanged in all groups under study. However, the percentage of breaks was high in suspension groups but not in respective groups of control. Thickness of the stained layer commensurate to the submembrane cytoskeleton did not change in the control groups and in the suspension group without lecithin injections but increased reliably in the suspension group that recieved injections by 27 % (p < 0.05) in comparison with its control.

Репликативный полипротеин 1а вируса желтухи свеклы (ВЖС) содержит консервативные домены лидерной папаин-подобной протеиназы (РСР), метилтрансферазы (MTR) и РНК хеликазы (HEL). Центральный район (central region, CR) между MTR и HEL ранее считали «вариабельным». Нами проведен компьютерный анализ CR, который позволил выявить новый консервативный домен между позициями 1287-1390 (здесь и далее приводится нумерация аминокислотных остатков белка 1а вируса желтухи свеклы, BYV), сохраняющийся у всех представителей рода Closterovirus. Этот домен содержит 4 предсказанных альфа-спиральных участка (альфа А – D) и три строго консервативные позиции – глютамат-1291, пролин-1380 и аргинин-1384. Кроме того, биоинформатический анализ позволил предсказать амфипатическую спираль в позициях 1368-1380 (входящую в состав участка альфа D). Гидрофобный домен CR-2 (позиции 1305-1494 белка 1а), вызывающий при экспрессии в растениях реструктуризацию эндоплазматического ретикулюма и образование подвижных глобул диаметром ~1 мкм, включает участки альфа В, С и D. Установлено, что экспрессия в растениях слитных белков CR-2:GFP и GFP:CR-2 вызывает сходный «глобулообразующий» фенотип, т.е. N-концевое или C-концевое положение маркера GFP в слитном белке не влияет на переформатирование мембран эндоплазматического ретикулюма. Проведен делеционный анализ CR-2 BYV. Показано, что делеционные варианты 1355-1494 и 1325-1484 сохраняют фенотип дикого типа (образование глобул и реструктуризация ЭР вокруг ядра клетки). Варианты 1375-1484, 1368-1484 и 1368-1432 индуцировали образование глобул, но утрачивали способность к реструктуризации ЭР. Внесение замен гидрофобных аминокислотных остатков на остатки серина и глицина в «минимальном» делеционном мутанте 1368-1432 блокировало образование глобул. Предложена рабочая гипотеза о влиянии консервативной амфипатической спирали 1368-1385 в белке 1а BYV на ремоделирование мембран ЭР растительной клетки и создание репликативных платформ при клостеровирусной инфекции.

Цель работы - оценка состояния кортикального цитоскелета волокон камбаловидной мышцы крысы в результате 6-часового антиортостатического вывешивания на фоне предшествующего, в течение 3 сут по 100 мкг/сут, введения смеси фосфатидилхолинов (лецитина). Данные о периметре волокон, толщине подмембранного цитоскелета и доле разрывов в нем относительно периметра получали, используя иммуногистохимическую окраску на альфа-актинин-4. Периметр волокон оставался неизменным во всех группах исследования. При этом доля разрывов была выше в группах вывешивания, чем в соответствующих контрольных группах. Толщина окрашенного слоя, соответствующего подмембранному цитоскелету, не менялась в контрольных группах и в группе вывешивания без лецитина, однако в группе вывешивания на фоне лецитина она достоверно увеличивалась по сравнению с соответствующей контрольной группой на 27 % (p < 0,05) соответственно.

Purpose of the work was to assess the cortical cytoskeleton of m. soleus fibers from rats after 6-hr tail-suspension preceded by 3 days of phosphatidylcholine (lecithin) injections at a dose of 100 µг/d. Data about the fiber perimeter, submembrane cytoskeleton thickness and percentage of bonds breaks along the perimeter were obtained using the alpha-actinin-4 anti-body stain. The fiber perimeter remained unchanged in all groups under study. However, the percentage of breaks was high in suspension groups but not in respective groups of control. Thickness of the stained layer commensurate to the submembrane cytoskeleton did not change in the control groups and in the suspension group without lecithin injections but increased reliably in the suspension group that recieved injections by 27 % (p < 0.05) in comparison with its control.