Search

Summary Post- COVID syndrome refers to the long-term consequences of a new coronavirus infection COVID-19, which includes a set of symptoms that develop or persist after COVID-19. Symptoms of gastrointestinal disorders in post- COVID syndrome, due to chronic infl ammation, the consequences of organ damage, prolonged hospitalization, social isolation, and other causes, can be persistent and require a multidisciplinary approach. The presented clinical practice guidelines consider the main preventive and therapeutic and diagnostic approaches to the management of patients with gastroenterological manifestations of postCOVID syndrome. The Guidelines were approved by the 17th National Congress of Internal Medicine and the 25th Congress of Gastroenterological Scientifi c Society of Russia.

The article presents a clinical case of the fatal Mallory- Weiss syndrome, which suddenly developed in an 86-year-old patient with a new coronavirus infection COVID-19, complicated by bilateral polysegmental pneumonia. The patient had no history of gastroesophageal refl ux disease, gastric ulcer or duodenal ulcer. The level of D-dimer on admission was elevated, but the patient was prescribed a reduced dose of anticoagulants (heparin). Despite the initial positive dynamics of the condition, the patient had a wave-like course of COVID-19, followed by the development of Mallory- Weiss syndrome, extremely severe post-hemorrhagic anemia and multiple organ failure, which became the cause of death.

Despite the high interest to the study of the effect of green spaces on the processes of substance migration in the system “lithosphere – biostrome – atmosphere”, the negative aspects of these interactions are not considered. A scheme of the circulation of heavy metals in this system is proposed; dependences for calculating the density of heavy metal flows between components are obtained. Methods are proposed and experimental studies of the dynamics of Fe, Cu, Pb, Zn concentration in each component of the system are carried out. A correlation between the processes of plant growing and the concentration of heavy metals in air was established. The flows of Fe, Cu, Pb, Zn in the system “lithosphere – biostrome – atmosphere” are calculated, graphic representations of their balance are proposed. The diagram analysis which made it possible to establish the fact of the influence of green spaces on their migration at a selected point was carried out.

The article presents the study results of the dynamics of persistent organic pollutants produced in the air during the decomposition of pesticide wastes. Analysis of the processes occurring in limited air volumes made it possible to establish patterns of changes in the concentration of such gases as hydrogen chloride and phosgene under the influence of a point source of their release. The obtained patterns complement similar studies conducted for more significant spatial scales.

The influence of agents modifying cholesterol in plasma membranes on the functional activity of transporter proteins (P-glycoprotein (P-gp) and the multidrug resistance protein 1 (MRP1)) in human lymphocytes has been studied. It was shown that changes in lateral distribution of cholesterol using the polyene antibiotic filipin, which disturb the structure and function of glycolipid microdomains in plasma membranes of lymphocytes lead to a decrease in the transport activity of both P-gp and MRP1. It was found that the treatment of human lymphocytes with the cyclic oligosaccharide methyl-beta-cyclodextrine, which leads to cholesterol depletion and reduction of lipid bilayer microviscosity in membranes of these cells, also decreases the functional activity of these proteins. It was concluded that the transport activity of P-gp and MRP1 depends on the modification of cholesterol in the membranes of human lymphocytes, i.e., is closely associated with the level of cholesterol and its lateral distribution.

We studied changes in the surface of erythrocyte membranes exposed to the action of zinc sulfate in the concentration range of 0.1–2.0 mM/l using methods of light scattering, spectrofluorimetry, and atomic force microscopy. Using the spectrofluorimetry method, we revealed a dose-dependent increase in the fluorescence intensity of a fluorescamine probe incorporated into erythrocyte membranes modified by zinc ions, which is indicative of an increase in the level of NH2 groups on the cell surface. Using atomic force microscopy, we revealed changes in the surface topography of erythrocyte membranes exposed to the action of zinc sulfate in the concentration range of 0.1–2.0 mM/l. By performing a correlation analysis, we revealed that the correlation length of the autocorrelation function of the erythrocyte surface irregularity profile directly related to the fluorescence intensity of fluorescamine incorporated into erythrocyte membranes (r = 0.9, p < 0.05) modified by zinc ions. We showed that, in the zinc sulfate concentration range of 0.1–2.0 mM/l, zinc oxides form in erythrocyte membranes, which is confirmed by the appearance of an absorption band at 330–340 nm and by an increase in the light scattering. At more considerable concentrations, we identified absorption bands characteristic of zinc protein complexes in erythrocyte membranes. A considerable decrease in the elongation of the scattering indicatrix of erythrocyte membranes caused by luminescence correlates with the content of zinc proteins. Polarization measurements confirm the enhancement of the aggregation of protein complexes observed by the atomic force microscopy method. The proposed complex approach can be used in studies on the action of various abiotic factors on biological cells.

The surface topography of erythrocyte membranes is studied by atomic force microscopy. Differences in fine structure of membranes are found. The structure of profiles of erythrocyte membranes modified by metals is smoother compared to unmodified erythrocytes. The autocorrelation function of irregularity pro-files of erythrocyte membranes and its parameter (the correlation length) are informative parameters of the action of toxic metals on the erythrocyte membrane surface. The content of metal in an erythrocyte membrane is determined from optical investigations of a suspension of membranes subjected to the action of lead and zinc ions. It is revealed that the luminescence of erythrocyte membranes is enhanced compared to reference data. The absorption spectra of erythrocyte membranes in the range 325–740 nm are calculated from the diffuse transmission and reflection coefficients of samples taking into account their luminescence. The possibility of determining the content of metals in erythrocyte membranes from optical measurements is demonstrated.

According to the World Health Organization, it is recorded steady growth of the number of chronic liver diseases, including nonalcoholic fatty liver disease (NAFLD), in recent years. As an independent nosological entity, NAFLD is one of the risk factors for cardiovascular diseases, associated with abdominal-visceral obesity, peripheral insulin resistance (IR), and is regarded as the hepatic component of Metabolic syndrome (MS). Nowadays there are no generally accepted national standards for diagnosis and treatment of NAFLD for physicians, gen- eral practitioners, gastroenterologists in Russia. This was the essential reason in their development. The main reason of The guidelines development is the absence of generally accepted national standards for diagnosis and treatment of NAFLD for physicians, general practitioners, gastroenterologists in Russia. These guidelines are based on the global and local data of treatment experience of NAFLD, recently published in reviews, analytical studies in the literature. Guidelines are intended for physicians, general practitioners, gastroenterologists and contain the description of the preferred approaches to the provision of diagnostic, curative and preventive care of patients NAFLD. The quality of recommendations was grading according to the GRADE approach.

The reaction of ethyl 5-phenylthioureido-3H-imidazole-4-carboxylate with bromoacetic acid afforded (imidazolylimino)thiazolidinones, which were transformed into the corresponding 5-arylidene-4-thiazolidinones by the reactions with aldehydes. Under the conditions of the Knoevenagel reaction, the thiazolidine ring in derivatives of 4-(4-oxothiazolidin-2-ylideneamino)-3H-imidazole-4-carboxamides was opened to form substituted guanidines.

The ability of the modern epidemic strains of influenza virus type A (subtypes H5N1, H3N2, H1N1pdm) and their surface proteins, hemagglutinin (HA) and neuraminidase to cause the activation of the cellular protein caspase-3 and stimulate the emergence of phosphatidylserine on the membrane of human endothelial cell line EAhy926 has been studied. It was questioned how the viruses and their surface proteins that were studied cause the activation of caspase-3 after 0.5 h of exposure that recorded immunogistotsitohimicheski. The test viruses and neuraminidase (concentration 10 μg/ml) led to the appearance of phosphatidylserine on the cell membrane in a time interval of 2-8 h from the beginning of the treatment, which was recorded by flow cytometry. The death of endothelial cells when exposed to the HA (in a concentration of 50 μg/ml) and in the same time frame was not accompanied by the appearance of phosphatidylserine. The specific feature of apoptotic cell death during the reproduction of the virus are described, as well as the effects of viral proteins.

Absorption and luminescence excitation and emission spectra of the amniotic fluid from females with a normal course of pregnancy and with fetation anomalies are investigated. It is shown that the amniotic fluid manifests, in addition to an intense UV luminescence, a luminescence in the range of 380–650 nm. The first luminescence peak with λmax = 430–450 nm is most likely due to the presence of NADH2 and hormones in the amniotic fluid, whereas the peak located at longer wavelengths with λmax = 520–540 nm is due to pigments (bilirubin, etc.). Differences in absorption spectra of the amniotic fluid in the case of the normal course of pregnancy and upon its pathologies are established. Luminescence emission and excitation spectra of the amniotic fluid in cases of intrauterine fetation pathologies are shifted toward the longwave region compared to normal pregnancy cases. It is concluded that the spectral-luminescent analysis of the amniotic fluid can be used as an additional rapid test for monitoring of intrauterine fetal pathologies.

The modern influenza virus subtypes H3N2, H5N1, and H1N1 reduced the metabolism of the endothelial cells within the range from 20% to 60% (compared with control). The degree of the activity of the dehydrogenase reduction depended on the dose of virus and time of virus reproduction. HA and NA also actively reduced the metabolism of the cells ranging from 5% to 60%, depending on the concentration of the proteins and time of their impact on cells. Neuraminidase was more active than hemagglutinin in the MTT test (at concentration 50 microg protein/ml).

The activity of membrane-bound NADH-methemoglobin reductase in erythrocytes and the physical state of lipids in erythrocyte membranes under oxidative stress in cells were studied. A decrease of the activity of membrane-bound NADH-methemoglobin reductase and a change of physical state of the lipid bilayer of membranes under oxidative stress were found in erythrocytes in vivo and in vitro.

The study was undertaken to study a relationship between the changes of some parameters of the biochemical and mineral composition of different plants, such as rape, pods, and lentil, and the levels of soil radiation pollution, by using the conventional methods. Radioactive pollution of dark-grey forest soils was found to cause a change in the biochemical composition of plant seeds even at the level of cesium 137 (137Cs) within the present temporary permissible levels (TPL) (600 Bq/kg): there were elevated concentrations of salts of potassium, phosphorus, ammonia nitrogen, catechols, sucrose, and some amino acids. With the radioactive cesium level exceeding the TPL, biochemical changes in the seeds depended on the species of the plants: in the rape seeds, the additional formation of sucrose and amino acids continued, but less intensively than with its lower radiation; the pod beans were significantly positively correlated with the increasing amounts of catechols.

The influence of agents modifying cholesterol in plasma membranes on the functional activity of transporter proteins (P-glycoprotein (P-gp) and the multidrug resistance protein 1 (MRP1)) in human lymphocytes has been studied. It was shown that changes in lateral distribution of cholesterol using the polyene antibiotic filipin, which disturb the structure and function of glycolipid microdomains in plasma membranes of lymphocytes lead to a decrease in the transport activity of both P-gp and MRP1. It was found that the treatment of human lymphocytes with the cyclic oligosaccharide methyl-beta-cyclodextrine, which leads to cholesterol depletion and reduction of lipid bilayer microviscosity in membranes of these cells, also decreases the functional activity of these proteins. It was concluded that the transport activity of P-gp and MRP1 depends on the modification of cholesterol in the membranes of human lymphocytes, i.e., is closely associated with the level of cholesterol and its lateral distribution.

A correlation was established in 708 stomach cancer patients between number of involved lymph nodes, on the one hand, and T- and B-cell immune response and morphological tumor pattern, on the other. That in turn significantly correlated with T-cell immune response and tumor localization. However, B-cell immune response and tumor size showed an inverse and less pronounced correlation with number of involved lymph nodes. Immunosuppression and metastatic spread are inter-connected; both quickly develop in succession in a node nearest to tumor and then continue invade. Immunosuppression is induced by tumor cytokines and innate regulatory T-cells which can either suppress or stimulate immune response, irrespective of tumor size.

In the hydraulic systems of industrial equipment, lubricating oils sometimes operate under wet conditions. Water gets into the hydraulic system as a consequence of temperature fluctuations (condensation-water)and also through entry of water-base lubricating/cooling fluids (cutting and grinding fluids) into the hydraulic system. Since IGP-series oils are being used more and more extensively in the hydraulic systems of machine tools, it has been of interest to study the thermooxidative stability of these oils under conditions involving water contamination.

Significance of prognostic factors of immunological response, tumor growth and age was investigated in 708 patients with stomach cancer. Such factors as T-cell immunological response, functional status of lymph nodes and localization on either the greater or lesser curvature of the stomach were identified as the most significant while T-cell immunological response, tumor size and number of involved lymph nodes appeared less significant but more harmful as far as survival was concerned. No significant correlation between pattern of growth, depth of invasion, age and local immunological response, on the one hand, and survival, on the other, was established.

In the present work we studied, by chemiluminescence measurements, the influence of lead on the production of reactive oxygen species (ROS) in haemolysates obtained from human erythrocytes incubated in the presence of different concentrations of lead acetate. Moreover, we evaluated the modification of proteins and lipids in human erythrocyte and lymphocyte membranes by using the fluorescence probes N-(1-pyrene)maleimide (PM), laurdan and pyrene. No significant changes in chemiluminescence were detected for erythrocytes incubated with 1–10 µM lead acetate for 3 h at 37 °C. By increasing the lead acetate concentration in cell suspensions up to 50 µM for the same incubation time, the percentage of chemiluminescence inhibition was ca. 20%. It was shown that, after incorporating fluorescence probes in the membrane lipid bilayer of erythrocytes and lymphocytes treated with 10 and[sol ]or 50 µM lead acetate, the total fluorescence intensity and the excimer to monomer intensity ratio of PM decreased and the generalized fluorescence polarization of laurdan decreased by 10–15%. The pyrene excimerization coefficient (κex) increased by 20% (in comparison with a magnitude of κex for white membranes isolated from intact erythrocytes) with 6–10 µM lead acetate for 3 h at 37 °C. The data obtained suggest that the effect of low concentrations of lead acetate does not cause production of ROS in erythrocytes in vitro, but can change the physicochemical state of proteins and lipids in erythrocyte and lymphocyte membranes. This effect is important because it influences the enzymatic activity and the functionality of receptors and channels present at the plasma membrane level, thus modulating the molecular composition of the intracellular space and cell functions. Copyright © 2005 John Wiley & Sons, Ltd.

The effect of high-intensity ultrasound (11.2-54.2 W/cm2, frequency 36 kHz) on the structural and functional state of erythrocytes was investigated. It was shown that, at short-term action of the ultrasound (up to 1 min), the dose-dependent hemolysis of erythrocytes occurs. It was found that the exposure to ultrasound of high intensity (54.2 W/cm2) leads to the disruption of the structural state of erythrocyte membranes, which manifests itself in a change of microviscosity of the lipid bilayer of membranes and inhibition of the activity of the lipid-dependent membrane-bound enzyme acetylcholinesterase.

The influence of calcium ions on the distribution of the fluorescent analog of phosphatidylcholine 2-(6-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)hexanoyl-1-hexadecanoyl-sn-glycero-3-phosphocholine (C6-NBD-PC) in membranes and transport of glutathione-S-conjugates in human erythrocytes was studied. It was supposed that both processes were performed by the multidrug resistance protein. It was found that the increase in intracellular calcium concentration tended to both the redistribution of about 35% of C6-NBD-PC in the inner layer of the membrane and a decrease in the exit of glutathione-S-conjugates from erythrocytes. In both cases, the intracellular calcium concentration varied in the physiological (nanomolar) range. The results testify that Ca2+ participates in the regulation of the activity of the multidrug resistance protein.

The reaction of ethyl 5-phenylthioureido-3H-imidazole-4-carboxylate with bromoacetic acid afforded (imidazolylimino)thiazolidinones, which were transformed into the corresponding 5-arylidene-4-thiazolidinones by the reactions with aldehydes. Under the conditions of the Knoevenagel reaction, the thiazolidine ring in derivatives of 4-(4-oxothiazolidin-2-ylideneamino)-3H-imidazole-4-carboxamides was opened to form substituted guanidines.

The effect of diamide on the physicochemical state of proteins and lipids of human erythrocyte membrane was studied. It was found that diamide at a concentration of 1 mM decreases the content of the SH-groups of membrane proteins by approximately 50%, resulting in enhanced vesiculation of erythrocytes upon metabolic exhaustion of cells. It was shown using fluorescein isothiocyanate-labeled concanavalin A and 4,4'-diisothiocyano-2,2'-stilbene disulfonate that diamide changes the structural state of the main integral protein of erythrocyte membranes, the band 3 protein. Changes in the microviscosity of the membrane lipid bilayer depending on diamide concentration were determined from the changes in the fluorescence parameters of the lipophilic probes (pyrene and 1,6-diphenyl-3,5-hexatriene). The level of lipid peroxidation products in membranes remained unchanged. It follows from these data that the SH-oxidizing agent diamide does not directly interact with the lipid bilayer of membrane and produces changes in the physicochemical state of lipids presumably by disrupting protein-lipid interactions that take place upon oxidation of the SH-groups and cross-linking of membrane proteins.

The parameters describing the structural and functional state of membranes depending on the level of reduced glutathione in erythrocytes were studied. It was shown, that the decrease in the concentration of reduced intracellular glutathione in erythrocytes upon metabolic depletion (prolonged incubation of cells at 37 degrees C in the absence of glucose) or a rapid irreversible depletion of glutathione with 1-chloro-2,4-dinitrobenzene enhances lipid peroxidation processes in membranes, inhibits the membrane-bound NAD.H methemoglobin reductase activity and decreases the intensity of 1,6-diphenyl-1,3,5-hexatrien fluorescence. The data obtained suggest that the depletion of reduced intracellular glutathione causes changes in the physicochemical state of the erythrocyte membrane: the accumulation of lipid peroxidation products, changes in the physical state of lipid bilayer and the inhibition of membrane-bound NAD.H-methemoglobin reductase activity.

tekhizdat, Moscow (1962), pp. 209-213. 7. A. A. Bratkov, E. P. Seregin, A. F. Gorenkov, et al., Chemistry of Rocket and Jet Fuels [in Russian], Khimiya, Moscow (1987), pp. 174-176. 8. G. I. Fuks, Physicochemical Principles of the Use of Surfactants [in Russian], FAN, Tashkent (1977), pp. 5-17. 9. G. I. Fuks and I. G. Fuks, Zh. Vses. Khim. Obshch. im. D. I. Mendeleeva, ii, No. 4, 414-421 (1966). i0. V. P. Tikhonov and G. I. Fuks, Khim. Tekhnol. Topl. Masel, No. 3, 8-11 (1982). Ii. V. G. Gorodetskii, E. P. Seregin, and N. P. Golenev, ibid., No. 12, 49-51 (1978).

It is shown that the oxidation of membrane protein SH-groups of human erythrocytes by diamide leads to the intensification of vesiculation and the formation on the cell surface of "senescent antigens". These processes were studied during prolonged incubation of erythrocytes at 37 degrees C in the absence of glucose. It was found that the formation of vesicules in ATP-depleted cells correlated with the appearance of "senescent antigens" (r = 0.9, p0.01). The oxidation of protein SH-groups takes place at the early stages of vesiculation and strengthening of autologous immunoglobulin binding, indicating that the oxidation of the other groups of membrane proteins plays the leading role in the modification of surface properties.

Genetic heterogeneity and evolutionary relationships among selected strains of adenovirus type 3 (Ad3) isolated in the former USSR (1976-1988) were examined using the restriction endonuclease Cfr131 with a 4-base recognition cleavage site. The population of adenovirus type 3 showed significant genetic instability. Evolution of genomic variants of Ad3 was found to have regional localization associated with definite periods of adenovirus circulation.

The effect of temperature on the activities of cytoplasmic and membrane-bound fractions of NADH-cytochrome beta 5 reductase on the total activity of methemoglobin reductase in intact human erythrocytes was studied within the temperature range of 20-50 degrees C. The above three activities showed a break in the Arrhenius plots at 42 degrees C which was attributed to irreversible inactivation of the enzymes. Thermal inactivation of methemoglobin reductase in erythrocytes was found to increase the methemoglobin content concomitantly with a decrease in the osmotic stability and activation of spontaneous cell hemolysis.

The spectro-fluorescent characteristics of synovial exudate in different diseases of the knee joint were studied. It was established that in pigmented villonodular synovitis the position of the maximum of fluorescence spectrum of synovial exudate was in the range of 510-530 nm and in synovitis of other etiology 430-440 nm. The authors propose a method of differential diagnosis of pigmented villonodular synovitis by fluorescent parameters of synovial exudate.

This article reports on a study of the principal conversions of hydrocarbons in hydrotreating a raffinate from phenol treating, obtained from a mixture of Volga-Ural and West Siberian crudes. It examines naphthenic hydrocarbons, alkylbenzenes, naphthalene hydrocarbons, and phenanthrenes. The degree of conversion of all groups of the aromatic hydrocarbons is considerably greater than the degree of conversion of the naphthenes. The greater the conversion of aromatics, the more significant are the changes in their physicochemical properties. Substantial decreases in the viscosity, density, and refractive index, and increases in the viscosity index are observed.

Effect of antibody to peripheral protein spectrin and antibody to integral protein of band 3 on kinetic parameters of pyruvate and glucose transport in the pink erythrocyte ghosts has been studied. It is shown that spectrin structure reorganization induced by the antibody to this protein has different effect on pyruvate and glucose transport parameters. Band 3 protein modification with the help of the antibody to this protein changes pyruvate transport parameters, while glucose transport is not changed. The data obtained show that facilitated diffusion of glucose and anions in the erythrocyte membrane is carried out by different carriers, the action of these carriers essentially depending on the structure state of spectrin.

The fluorescence of intensivity of membrane-bound diphenylhexatriene (DFHT) of erythrocytes of the cancer patients is found to increase as compared to that of donors. No reliable differences are detected in a degree of fluorescence polarization of DFHT and pyren excimerization in erythrocyte membranes of cancer patients and donors. The data obtained show that under the development of malignant tumours the structure state of lipid bilayer of erythrocyte membrane does not undergo significant changes. However an increase of the fluorescence intensivity of the membrane-bound DFHT, evidently, is the result of changes in protein-lipid interactions in the membrane.

Composition analysis of natural populations of adenovirus serotype 3 (Ad 3) strains--based on samples selected out of 170 strains isolated in different regions of the U.S.S.R. from 1976 to 1981--has demonstrated their inhomogeneity with respect to cytopathogenicity and haemagglutination activity. The strains were classified into 3 groups: low, medium and highly cytopathic. The cytopathogenicity of the strains appeared to be a rather variable feature dependent on regional climate and on seasonal complexity. In summer low cytopathogenic viruses predominated. The epidemic activity of circulating adenoviruses (proportion of adenoviruses in the aetiology of acute respiratory disease) correlated with the level of their cytopathic activity.

Effect of 4,4-dyisotiocyanostilben-2,2-disulfonate (DIDS) and 1-ftor-2,4-dinitrobenzol (NDFB) on the rate of phosphate ion transport in erythrocytes, filtrability and thermal stability of erythrocytes and on the structural state of the erythrocyte membrane estimated by UV-fluorescence, PAAG--electrophoresis and measuring of the activity of membrane-bound acetylcholinesterase (AChE) has been studied. Unpenetrating anion transport inhibitor DIDS is shown to induce structural modifications of bands 3 of protein and AChE, while DNFB penetrating the membrane causes a significant reorganization of many membrane proteins (including spectrin) resulting in changes of transport and mechanical properties of erythrocytes.

Changes in the acetylcholinesterase activity, thermal and osmotic stability of erythrocyte membranes of the cancer patients are found as compared with this activity of erythrocyte membranes of donors. No differences were detected in the rate of phosphate anion transfer through the erythrocyte membranes in the examined persons. The data obtained show that the development of malignant tumours is followed by the changes in the structural and functional state of surface components of erythrocyte membranes.

Temperature transitions of spectrin in solution and in human erythrocyte membranes are recorded in the region t greater than 40 degrees C by irreversible changes in protein fluorescence spectra. Structural changes are completed 20 min after the sample incubation at an increased temperature. Both for isolated spectrin and for erythrocyte ghosts the temperature of half-transition is 46 +/- 1 degree C. There is no transition in the membranes after the removal of spectrin. Transitions in erythrocyte ghosts and in spectrin solution disappear at pH 5 when spectrin is in an aggregated state. Spectrin is suggested to be responsible for the transitions at 50 degrees C; its state in the cells areas more thermostable than in isolated membranes.

Mediated agglutination of erythrocytes was studied in the presence of concanavalin A (Con A). Agglutinability of erythrocytes from cancer patients was found to be higher than that of normal cells as a result of chemical factors present in the blood plasma which transform the cell surface, the number of Con A receptors remaining unchanged. It is concluded that increased agglutinability of erythrocytes from cancer patients is mainly due to a decrease in the negative charge of cells and the appearance of echinocytic forms.