Vol 24, No 2 (2024)

Artificial neural networks are capable of efficiently processing large data sets, as well as solving the tasks of prediction, classification and data recovery. The article considers each of the above tasks in detail and studies literature sources devoted to the topic under study. Artificial neural networks cope with the tasks with a high degree of accuracy. The methods of application of neural networks for the analysis of systemic haemodynamics are described. Modern neural networks can analyse medical data and are able to work with incomplete data, find hidden patterns in them, and can be adapted to solve a wide range of problems. Our laboratory is developing an artificial neural network capable of classifying indicators describing the state of haemodynamics of subjects and recovering missing or incomplete data. Thus, artificial neural networks can act as an efficient method of analysing systemic hemodynamic parameters.

BACKGROUND: Endoprosthetics of large joints is a frequently performed operation in traumatology practice. The progression of local infectious sequela among postoperative patients is of major socio-economic importance since more than 30% of cases of inflammatory postoperative reactions are complicated by sepsis. In recent years, new criteria have been sought to assess the risks of infection in the field of surgical intervention, and prognostic scales have also been developed.

AIM: The aim of the study was to evaluate the prognostic value of coagulological, biochemical and hematological indicators of the risk of hemorrhagic complications in patients after hip replacement.

MATERIALS AND METHODS: The study included 85 patients who were in the clinic of Traumatology and Orthopedics of the I.I. Mechnikov for planned hip replacement. The average age of the patients was 64 ± 10 years. There were 46 women (54%), 39 men (46%). All patients underwent clinical and laboratory examination before surgery, the day after surgery and before discharge. All patients received rivaroxaban (10 mg 1 time/day) after surgery for the prevention of venous thromboembolic complications (46 patients) or apixaban (2.5 mg 2 times/day) (39 patients) during the entire period of stay in the clinic. Retrospectively, depending on the occurrence of complications, the patients were divided into 2 groups: group 1 — 78 patients (42 women and 36 men), whose postoperative period passed without complications, and group 2 — 7 patients (4 women and 3 men), who had hemorrhagic cases. Screening coagulogram (International Normalized Ratio, Activated partial thromboplastin time, fibrinogen) was performed on the STA Compact analyzer (Stago, France), biochemical parameters (alanine aminotransferase, aspartate aminotransferase, creatinine, total calcium, ionized calcium, serum iron, C-reactive protein) were determined on the COBAS Integra 400plus analyzer, hematological parameters on the DxH800 analyzer (Beckman Coulter, USA).

RESULTS: A retrospective analysis revealed that a decrease in serum iron in male patients before surgery is a marker of the prognosis of hemorrhagic complications. Prognostic significant laboratory indicators of the development of hemorrhagic complications in patients in the early period after hip replacement include an increase in fibrinogen and C-reactive protein; a decrease in serum iron. During the recovery period, the concentration of C-reactive protein and the relative number of monocytes are the most significant for assessing the risk of complications.

CONCLUSIONS: Among the laboratory indicators in the structure of the weight coefficients of the prognosis of complications in patients undergoing hip replacement, it is necessary to evaluate the concentration of serum iron before surgery, especially in men, in the early postoperative period — C-reactive protein, fibrinogen and serum iron and at discharge — C-reactive protein and the number of monocytes as additional criteria for the risk of complications.

Background: The barrier properties of epithelial and endothelial cells are usually studied in vitro when cells are cultured on mesh inserts in culture plates, and it is necessary to assess the state of the cell monolayer on the membrane of the inserts before the experiment. Typically, monolayer density is analyzed by passing a fluorescent label through the insert with cells or by measuring the transendothelial resistance (TEER) of the cell layer. Many studies use both methods of assessing monolayer integrity in parallel, depending on the purpose of the study. The TEER method also allows to record early changes in the monolayer state under the action of various substances.

Aim of this work is to demonstrate the possibility of TEER measurements using the proposed device (conductometer) made from freely available components using endothelial/epithelial cells as an example.

Materials and Methods. A device (conductometer) for measuring TEER, created on the basis of easily accessible components, is presented. The device was tested by culturing two cell lines – hybridoma of endothelial origin Ea.hy926 and human colon adenocarcinoma Caco-2. Caco-2 cells were cultured for 22 days and Ea.hy926 cells were cultured for 7 days. The integrity of the cell monolayer and the density of intercellular contacts were evaluated by the TEER value determined by the proposed conductometer, as well as by the fluorescein permeability of the cell monolayer.

Results: The results of TEER measurements using the proposed device and at the same time, the fluorescein permeability of the cell monolayer during the cultivation of Caco-2 and EA.hy926 cells are presented. For Caco-2 cells from the moment of 100% confluence the TEER value gradually increased reaching maximum values by 20-21 days, after which it decreased slightly. The permeability values decreased as the cells were cultured, indicating the formation of dense contacts. For EA.hy926 cells the rise in TEER values are observed on day 3  and decrease was observed on day 7. The results of TEER and permeability obtained by the proposed conductometer have a strong inverse correlation for both cell lines and are in good agreement with each other.

Conclusions. The presented device, made on the basis of simple and affordable components, is similar to commercially available devices and can be used to study the integrity and density of a monolayer in the cultivation of epithelial/endothelial cells, to study the processes of trans/paracellular transport under the action of various substances, as well as in experiments with the co-cultivation of various cell lines.

BACKGROUND: Arginine vasopressin has been implicated in the modulation of stress and pain. The influence of a synthetic analogue of arginine vasopressin, 1-deamino-8-D-arginine-vasopressin, оn pain sensitivity, stress reactivity, levels of monoamines and brain neurotrophic factor in a model of paw electrical stimulation in rats has not been studied.

AIM: The aim was to evaluate the effect of a synthetic vasopressin analog, 1-deamino-8-D-arginine-vasopressin, on pain sensitivity and the content of norepinephrine, serotonin, dopamine, brain neurotrophic factor in the parietal cortex and spinal cord in electrocutaneous paw stimulation test in rats.

MATERIALS AND METHODS: The study was conducted on male Wistar rats who were injected with 1-deamino-8-D-arginine-vasopressin intranasally once a day for 5 days in small (single 20 ng, course 100 ng) and large doses (single 2 ug, course 10 ug). The content of brain neurotrophic factor in the parietal cortex and spinal cord, and corticosterone in blood serum were determined using enzyme immunoassay. The levels of norepinephrine, serotonin, dopamine and their metabolites in the brain were evaluated using high-performance liquid chromatography.

RESULTS: 1-Deamino-8-D-arginine-vasopressin in different doses reduced pain sensitivity in rats, more pronounced when administered in large doses. The peptide in small doses in the parietal cortex increased the content of dopamine and reduced the levels of 5-hydroxyindolacetic acid, a metabolite of serotonin; in the spinal cord, it reduced the content of 5-hydroxyindolacetic acid. 1-Deamino-8-D-arginine-vasopressin in high doses in the parietal cortex increased the content of dopamine and reduced the levels of 5-hydroxyindolacetic acid; in the spinal cord ― reduced the content of serotonin and 3,4-dihydroxyphenylacetic acid, a metabolite of dopamine; increased the levels of norepinephrine and homovanilic acid, a metabolite of dopamine. The peptide had no effect on corticosterone levels in the blood and brain neurotrophic factor levels in the brain in rats.

CONCLUSIONS: The analgesic effects of 1-deamino-8-D-arginine-vasopressin were revealed with intranasal administration in different subendocrine doses. Regardless of the administered doses, dopamine and serotonin at the supraspinal level were involved in peptide-induced anesthesia; serotonin at the spinal cord level. More pronounced analgesia with the administration of 1-deamino-8-D-arginine-vasopressin in high doses was due to the additional involvement of dopamine and norepinephrine at the spinal cord level.

BACKGROUND: According to the World Health Organization, microbial resistance to antibiotics is one of the most serious threats to human health, food safety and economic development. Antimicrobial peptides of animal origin, to which resistance is difficult to develop, appear to be a promising option to overcome this problem. To solve one of the problems in the practical use of peptides — their rapid degradation in blood plasma — dendrimerization of linear analogues of already existing antimicrobial peptides can be used. This work shows that dendrimers of shortened analogue of the natural proline-rich peptide ChBac3.4 are superior in antimicrobial activity to the original peptide and are much more stable in blood serum. At the same time, as the original peptide, branched analogues do not have hemolytic activity.

AIM: The aim of this study is to develop new structural analogues of a peptide that have improved stability in blood serum while maintaining high antimicrobial activity. To achieve this, we intend to create dendrimeric (branched) molecules by synthesizing peptides using solid-phase methods.

MATERIALS AND METHODS: We will investigate the antimicrobial properties of the peptides using the method of serial dilutions in a liquid nutrient medium against both Gram-positive and Gram-negative bacteria. We will also assess the stability of the peptides by culturing them in the presence of human blood serum.

RESULTS: After making modifications to the original peptide, we expect to see a significant increase in its antimicrobial activity against all strains tested. Additionally, we anticipate that the resistance of these peptides will increase many times over.

CONCLUSIONS: Overall, our findings suggest that dendrimerization can effectively improve the properties of proline-rich peptides, making them more suitable for use in medical applications.

BACKGROUND: Toxic hepatitis is characterized by a significant severity of the course and by high mortality. So, search for effective means of correcting this condition seems to be relevant. It has previously been shown that some thiazolo[5,4-b]indole derivatives are capable to prevent experimental toxic liver damage in laboratory animals. In continuation of this direction, the study of the hepatoprotective properties of synthetic derivatives of thiourea 2-aminobenzothiazole and IEM-2320 was undertaken.

AIM: To study the potential hepatoprotective properties of 2-aminobenzothiazole and IEM-2320 in acute carbon tetrachloride poisoning.

MATERIALS AND METHODS: Experiments were carried out on 30 male white outbred rats (150–270 g). On a model of carbon tetrachloride poisoning (50% solution of CCl₄ in vaseline oil, 0.2 ml/100 g of body weight), the potential hepatoprotective properties of 2-aminobenzothiazole (32 mg/kg) and IEM-2320 (20 mg/kg) were investigated. Ademethionine (Heptral, AbbVie, S.r.L, Italy) at a dose of 20 mg/kg was used as a comparison drug. The studied drugs were administered intraperitoneally 4 times: one hour before the introduction of CCl₄, and then — for three subsequent days after the poisoning with CCl₄. The results were compared with those of 2 control groups. Animals of the 1st control group were not exposed to CCl₄, instead of the studied drugs, they were injected with an equivalent volume of saline solution (0.2 ml/100 g of body weight). Animals of the 2nd control group did not receive any treatment after the CCl₄ poisoning. Blood was taken on the seventh day of the experiment. The total contents of protein, glucose, and total cholesterol in blood serum were determined, and the activities of alanine aminotransferase and aspartate aminotransferase were evaluated.

RESULTS: Under the CCl₄ poisoning, the administration of 2-aminobenzothiazole led to a significant decrease in the concentrations of glucose, total protein, total cholesterol and alanine aminotransferase activity. When IEM-2320 was administered under the condition of poisoning, a decrease in the concentrations of total protein, glucose, urea, total cholesterol, and the alanine aminotransferase activity was observed.

CONCLUSIONS: A significant decrease in the biochemical parameters of blood serum after administration of 2-aminobenzothiazole and IEM-2320 under the condition of CCl₄ poisoning demonstrates thir potential hepatoprotective properties under acute hepatotropic poisonings.

BACKGROUND: Substantia nigra is the main dopaminergic center of the brain. Massive loss of dopaminergic neurons is characteristic for Parkinson’s disease. Arterial hypertension is considered a possible risk factor for Parkinson’s disease development, but to date there is no understanding of the mechanisms that may mediate the effect of high blood pressure on the death of dopaminergic neurons and the development of Parkinson’s disease. Since neuroglia is known to make a major contribution to the pathogenesis of neurodegeneration, it is important to evaluate the effect of arterial hypertension on the functional status of glial cells in the Substantia nigra.

AIM: The aim of the study was to analyze the features of morphofunctional state of both microglia and astroglia in the Substantia nigra of spontaneously hypertensive rats.

MATERIALS AND METHODS: Brain samples from Wistar rats (n = 3) and from spontaneously hypertensive SHR rats aged 9 months (n = 4) were used as a material for the study. Brain sections were immunostained for tyrosine hydroxylase to identify the Substantia Nigra, for calcium-binding protein Iba-1 to identify microglia, and for glial fibrillary acidic protein to identify astrocytes.

RESULTS: Compared to the control, microglial cells in the Substantia nigra of spontaneously hypertensive rats show signs of moderate activation manifested in significant thickening of the processes of microgliocytes. Single microgliocytes exhibit ameboid morphology, indicating their strong activation. A close spatial relationship with the bodies of dopaminergic neurons was noted for some identified microgliocytes. Astrocytes in Substantia nigra of both Wistar rats and SHR rats show no signs of activation.

CONCLUSIONS: Arterial hypertension may be one of the causes of neuroinflammation mediated by microglia in the Substantia nigra.

BACKGROUND: Binge eating disorder is the most common eating disorder, characterized by recurrent episodes of binge eating during which a person consumes excessive amounts of food in the absence of hunger. These episodes of binge eating are usually accompanied by a feeling of lack of control with an inability to refrain from eating or stop eating once it has started. A rodent model of binge eating disorder shows that intermittent consumption of energy-dense foods induces binge eating behavior independent of weight gain.

AIM: To study the effect of the ghrelin receptor antagonist Agrelax on compulsive overeating in rats.

MATERIALS AND METHODS: The study involved 30 male Wistar rats. To model compulsive overeating, animals received high-calorie food (a mixture based on chocolate-nut butter spread) 3 times a week while maintaining free access to standard pelleted food and water. Compulsivity in behavior was assessed using the pellet burying test. The ghrelin receptor antagonist Agrelax was administered intranasally, 1 µg/1 µl, 10 µl in each nostril for 7 days.

RESULTS: Compulsive behavior was assessed using the pellet burying test. The experimental group of animals receiving a high-calorie diet buried a significantly larger number of pellets than the control group (p < 0.01). After a 7-day course of Agrelax, the number of buried balls decreased significantly, reaching the values of the control group (p < 0.05). A technique for compulsive overeating in rats was developed by giving high-calorie food 3 times a week. After a 7-day course of Agrelax, the consumption of high-calorie foods significantly decreased (p < 0.05). The daily consumption of standard feed in the group did not differ compared to the control group. However, after the course of Agrelax administration, the consumption of standard feed decreased.

CONCLUSIONS: The data obtained suggest new ways of synthesizing peptide pharmacological agents based on ghrelin and its antagonists for the correction of food addiction.

BACKGROUND: Cytokines are important participants in the atherosclerotic process. The product of T-helpers and mast cells, interleukin-4, causes activation of endothelial cells and induces polarization of macrophages into anti-inflammatory M2 phenotype.

AIM: The aim was to study the influence of interleukin-4 on the activation of transendothelial transport of low-density lipoproteins.

MATERIALS AND METHODS: Low-density lipoproteins transendothelial transport was evaluated in a two-chamber model on a monolayer of human endothelial cell line EA.hy926. For that, 200 mkg/ml of low-density lipoproteins, and 1, or 10, or 100 ng/ml of interleukin-4, or 10, or 50 ng/ml of interleukin-6, or 50 ng/ml of tumor necrosis factor, or 10 ng/ml of interleukin-4 and 50 ng/ml of tumor necrosis factor, or a phosphate buffer saline were added to the cells on 24 h. The integrity of endothelial monolayer was controlled by the passage through 1 mkg/ml of fluorescein Na. The levels of mRNA and proteins in the cells were determined by reverse transcription polymerase chain reaction and Western blotting, the activity of matrix metalloproteinases-1, -2 and -9 in the culture medium — by zymography, interleukin-6 and -8 concentrations — by enzyme-linked immunosorbent assay.

RESULTS: Interleukin-4 had no effect on the passage of low-density lipoproteins through the monolayer of endothelial cells in basal and tumor necrosis factor stimulation conditions. At the same time, interleukin-4 suppressed interleukin-8 secretion by cells and increased their production of interleukin-6. The latter also did not cause the changes in the permeability of endothelial monolayer. In addition, interleukin-4 did not affect the expression of CAV, SCARB1, ACVRL1 genes, encoding proteins involved in low-density lipoproteins transendothelial transport. An addition of interleukin-4 or -6 to the cells did not change the activity of the matrix metalloproteinases.

CONCLUSIONS: Interleukin-4 does not affect the transendothelial transport of low-density lipoproteins, while modulating the production of other cytokines by endothelial cells. In the future, it is necessary to establish the effect of a wider range of cytokines produced by intimal cells on low-density lipoproteins transendothelial transport, as well as to clarify the molecular mechanisms of influence of tumor necrosis factor on this process in order to identify new targets for atherosclerosis therapy.

BACKGROUND: The substances that make up mixed saliva exhibit activity against bacteria, viruses and fungi. Among them are various cationic antimicrobial peptides: alpha- and beta-defensins, cathelicidins, histatins, but their concentration is relatively low. On the other hand, saliva widely contains a fraction of proline-rich proteins and products of their proteolysis — peptides, the functions of which currently remain poorly studied and unclear. The study of the antimicrobial activity of proline-rich proteins, in particular, when they act together with antimicrobial peptides, and the deciphering of the molecular and cellular basis for the implementation of the protective functions of proline-rich peptides is an urgent task in medicine and biology. The data obtained will help to understand the mechanisms of anti-infective protection of the oral cavity with the participation of the innate immune system, and in the future will allow the creation of drugs based on proline-rich proteins in humans and animals.

AIM: Study of the individual antibacterial action of proline-rich salivary proteins, their combined action with the antimicrobial proteins lactoferrin and lysozyme, as well as with one of the most significant endogenous protective peptides — cathelicidin LL-37 on the formation of bacterial biofilms.

MATERIALS AND METHODS: Human lactoferrin and egg lysozyme were used in the work. The minimum inhibitory concentrations of peptides against gram-negative and gram-positive bacteria were estimated using serial dilutions in a liquid nutrient medium. Using serial dilutions using the “chessboard” method, it was shown that proline-rich proteins can increase the antibacterial activity of innate immunity peptides present in the oral cavity. The ability of combinations of cationic proline-rich peptides with cathelicidin LL-37 to prevent the formation of bacterial biofilms was studied.

RESULTS: In the presence of proline-rich peptides, the antimicrobial activity of some antimicrobial peptides and proteins present in saliva against planktonic bacteria increases. The combined action of proline-rich proteins with LL-37 increases the inhibition of bacterial biofilm formation.

CONCLUSIONS: As a result of the study, it was shown that the analyzed cationic proline-rich peptides of human saliva exhibit anti-inflammatory effects, which suggests their significant role in the regulation of inflammatory processes in the oral cavity, as well as their participation in recovery processes.