Introduction. The balance of estrogens and progesterone ensures the harmonious development of the uterus during pregnancy: progesterone provides an increase in the number of myocytes, and estrogens – their volume. Hormonal balance achieved through the catabolism of estrogens in the liver plays an important role in postpartum uterine involution. In this regard, liver diseases during pregnancy can disturb the elimination of estrogens, which leads to hyperestrogenism and problems with maintenance of pregnancy, and can also cause impaired uterine postpartum involution. Aim. The study of the expression of estrogen and progesterone receptors in the myometrium of C57Bl/6 mice during pregnancy and the late postpartum period in acute CCl4-induced hepatosis and in its correction with immobilized hyaluronidase (IH). Materials and methods. The experiment was performed on 100 female C57Bl/6 mice. Acute hepatosis was induced on the 13th day of pregnancy by a single intraperitoneal injection of a 50% carbon tetrachloride solution in olive oil at a dose of 0.3 ml/kg. The mice were divided into four groups: group 1 (control) – intact pregnant mice; group 2 – mice with acute toxic hepatosis; group 3 – pregnant mice with induced acute toxic hepatosis and its correction with IH on the 14th day of pregnancy; group 4 – intact pregnant mice receiving IH on the 14th day of pregnancy. In all groups, sampling was carried out on the 18th and 21st days of pregnancy and on the 1st, 10th and 15th days after parturition. The numerical density (Nai) of positively stained nuclei of the receptors in the test area in myocytes was calculated, regardless of the staining intensity. Results. During pregnancy in acute CCl4-induced hepatosis, the expression of progesterone and estrogen receptors in the myometrium does not change and corresponds to that of intact pregnant mice. In animals with acute CCl4-induced hepatosis, in the late postpartum period (up to 15 days), an increased expression of estrogen receptors in the myometrium is noted, with relatively stable expression rates of progesterone. In the correction of acute CCl4-induced hepatosis with IH, the expression of estrogen receptors in the postpartum period decreases and generally corresponds to similar indicators in intact pregnant mice. Conclusion. In acute CCl4-induced hepatosis, the balance of estrogen and progesterone receptors in the myometrium in the postpartum period is disturbed. In the correction of acute CCl4-induced hepatosis with IH, the levels of expression of estrogen and progesterone receptors in the myometrium are normalized which contributes to the completion of postpartum uterine involution.

Introduction. One of the stages in the development of medicinal products (MP) is the study of safety assessment. Determination of possible toxic effects, establishment of the nature and severity of the damaging effect of drugs under development during their administration is carried out, including studying the effect on hematologic parameters and hematopoiesis. Aim. To assess the possibilities of PEG-HYAL impact on hematologic parameters and hematopoiesis when administered per os. Material and methods. Hyaluronidase immobilized by electron beam synthesis on polyethylene oxide (PEG-HYAL). Laboratory animals – white mature conventional outbred rats and chinchilla rabbits. Hematological parameters were determined using an automatic hematological analyzer Abacus (Diatron, Austria) and conventional manual methods of research. The effect of PEG-HYAL on the state of medullary hematopoiesis was determined by counting the total number of myelokaryocytes per femur (106/femur) and myelograms on smears (in rats). The percentage of individual cell forms in rat myelogram counts was converted to absolute numbers, x106 cells per femur. In rabbits, the myelogram indices of bone marrow, taken from the sternum segment, were determined in relative units (%) only. Results. The analysis of the obtained results of the effect of PEG-HYAL administration on hematologic indices in rats (male and female) did not show any pathological changes. The revealed changes in hematologic parameters in rats are neither significant, nor systemic and dose-dependent. PEG-HYAL administration to rabbits has no toxic effect on hematologic parameters with multiple intragastric administration. Administration of PEG-HYAL for 28 days to rats in all studied doses does not produce a toxic effect on the main studied bone marrow parameters. While the revealed changes in the quantitative composition of myelokaryocytes are non-systemic and reversible. PEG-HYAL administration has no toxic effect on bone marrow indices of rabbits when administered intragastrically in the studied doses during 28 days. Conclusion. Interpretation of the obtained results, concerning the effect of the per os PEG-HYAL administration to experimental animals on hematologic parameters and hematopoiesis, can be used as a preclinical dossier of the drug.

In a series of randomized trials, SGLT2 inhibitors have demonstrated a reduction in hospitalization and mortality in patients with chronic heart failure. However, more and more often, there is evidence of a decrease in iron levels in the blood while taking gliflozin. This review examines the pathogenetic basis of the dynamics of hematopoiesis in patients with diabetes mellitus and chronic heart failure. Changes in hematocrit, hemoglobin, reticulocyte count, and erythropoietin reported in prospective analyses are discussed. The increase in hemoglobin levels observed with gliflozins contributes to improved tissue oxygenation, thereby exerting some protective effect. Active iron utilization will result in increased levels of soluble transferrin receptors and iron-binding capacity, coupled with a decrease in ferritin, transferrin saturation index and hepcidin. Thus, long-term use of SGLT2 inhibitors, while having a positive effect on hemoglobin levels, can lead to latent iron deficiency. To understand the significance of this problem, it is necessary to initiate large cohort studies.

Hyaluronidase increases tissue permeability and diffusion of the extracellular fluid by cleaving hyaluronan, the primary component of the extracellular matrix. Hyaluronidase pegylation (Hyal-PEG) decreases its clearance and enhances biodistribution. The pro- and anticancer activity of Hyal-PEG and a combination of Hyal-PEG with doxorubicin were studied in vitro (morphological analysis of rat glioblastoma 101.8 spheroids) and in vivo (by the survival time of rats after intracerebral transplantation of the tumor and morphological analysis). In the presence of doxorubicin and Hyal-PEG in the culture medium in vitro, spheroids lost their ability to adhere to the substrate and disintegrate into individual cells. Intracerebral transplantation of the tumor tissue with Hyal-PEG did not accelerate glioblastoma growth. The mean survival time for animals receiving transplantation of the tumor alone and in combination with Hyal-PEG was 13 and 20 days, respectively. In one rat with transplanted tumor and Hyal-PEG, this parameter increased by 53%. The survival time of rats receiving systemic therapy with doxorubicin and Hyal-PEG significantly increased (p=0.003). Antitumor effect of therapeutic doses of doxorubicin combined with Hyal-PEG was demonstrated on the model of rat glioblastoma 101.8 in vitro. Hyal-PEG inhibited adhesion of tumor cells, but did not cause their death. Transplantation of Hyal-PEG-treated tumor did not reduce animal survival time. Systemic administration of therapeutic doses of doxorubicin with Hyal-PEG increased survival time of rats with glioblastoma 101.8.

Introduction. Testicular hyaluronidase preparations are widely used in medical practice. Modification of native biologically active molecules by electron beam PEGylation allows to improve their pharmacokinetic properties, which determines a subsequent improvement of pharmacodynamic effects. The development of an original oral drug with a pharmacologically active core, which is hyaluronidase, is promising, but requires studying the safety of use at the preclinical stage. Aim. Ultrastructural evaluation of hepatotoxic effects of PEGylated hyaluronidase in vitro. Materials and methods. The object of a study was testicular hyaluronidase PEGylated on polyethylene oxide (PEG-HYAL) using electron beam synthesis. The culture medium is a continous culture of human liver cells Chanq liver. The cytotoxic effect was detected by the MTT assay. Ultrastructural changes were evaluated by electron microscopy. Results. The original drug PEG-HYAL in the studied concentrations of 37, 75 and 150 U/ml has no cytotoxic effect on the human liver cell culture (hepatocytes). Cell viability is virtually at the control level when PEG-HYAL administration at concentrations of 37 and 75 U/ml, and in the maximum concentration of 150 U/ml, cell proliferation is stimulated significantly, as evidenced by an increase in cell viability up to 106%. The results of evaluation of ultrastructural changes in hepatocytes showed that exposure to PEG-HYAL in all concentrations leads to the enhancement of metabolic processes in cells, development of autophagy, which is one of the main homeostatic processes. Conclusion. The drug PEG-HYAL in all studied concentrations has no toxic effect on the human hepatocyte culture. The results obtained can be used in further research in the development of PEG-HYAL.

The widespread use of testicular hyaluronidase preparations determines the particular interest in the development of oral dosage form. The drug under development, which is hyaluronidase pegylated using electron beam immobilization technology (PEG-GIAL), requires an assessment of its safety. Identification of possible neurotoxic action, as well as the influence on cardiac function seems to be very relevant. Aim of the study was to investigate the effect of PEG- GIAL on behavioural reactions and electrical activity of the heart of experimental animals. Material and methods. Eight hundred of white outbred rats (male and female) were used as experimental animals. The effect of PEG-GIAL on the central nervous system was determined using the «open field with holes» test, examining such characteristics as emotional reactions and orientation-research behaviour. The functional state of the cardiovascular system was assessed by electrocardiography data. Results. PEG-GIAL administration in all studied doses does not lead to changes in the functional activity of CNS, does not have a pronounced effect on the indices of orientation-research behaviour and emotional reactions in laboratory animals. No statistically significant changes in the cardiogram of rats were revealed, including no intersex differences. Conclusions. PEG-GIAL administration in all studied doses has no toxic effect on the electrical activity of the heart and has no pronounced effect on changes in the functional activity of the CNS and behavioural reactions.

Введение. Дети с патологией полости рта и челюстно-лицевой области подвержены риску локальных тромботических событий, которые ухудшают результаты хирургического лечения. Цель исследования: оценка состояния системы гемостаза у детей с хирургической патологией челюстно-лицевой области традиционными и интегральными методами. Материалы и методы. Проведено ретроспективное обсервационное исследование у 271 ребенка с хирургической патологией ротовой полости и челюстно-лицевой области. Собраны демографические, клинические и лабораторные данные, исследованы параметры гемостаза. Больные распределены на 4 группы: сосудистые мальформации (n = 115), воспаление (n = 66), гемангиомы (n = 16) и контрольная группа (n = 47). Проведено сравнение клинических и лабораторных данных. Результаты. Частота локальных тромботических событий при сосудистых и воспалительных заболеваниях была выше (padj = 0,001 и padj < 0,001 соответственно) по сравнению с контрольной группой и составила 20% и 31,8% соответственно. У детей с тромботическими событиями срок госпитализации составлял 24 [16; 33] дней, тогда как у детей без тромботических событий — 12 [8; 19] дней (p < 0,0001). В группе «Воспаление» у 35% пациентов уровень фибриногена был выше 3,5 г/л. В группах «Мальформации» и «Воспаление» все показатели тромбоэластографии имели гиперкоагуляционную направленность в отличие от других групп (p < 0,0001). Тромбодинамика в группах «Мальформации» и «Воспаление» выявила спонтанные сгустки в пробе крови; скорость роста и размеры сгустка отличались от референтных значений. Заключение. Необходим комплексный мониторинг параметров гемостаза. Стандартные клоттинговые тесты не позволяют выявить ранние признаки гиперкоагуляции. Интегральные методы контроля гемостаза эффективны для ранней диагностики тромботических событий. Тест тромбодинамика лучше обнаруживает скрытый от других методов гиперкоагуляционный потенциал до хирургического вмешательства. Регионарные тромботические события при хирургической патологии полости рта и челюстно-лицевой области приводят к удвоению сроков пребывания в стационаре. Introduction. Children with oral and maxillofacial pathologies are at risk of local thrombotic events, which exacerbate the outcomes of surgical treatment. Aim: to assess the hemostasis in children with surgical oral and maxillofacial pathology using both conventional and integral methods. Materials and Methods. A retrospective observational study was conducted on 271 children with surgical oral and maxillofacial pathology. Prior to surgical intervention, demographic, clinical and laboratory data were collected as well as hemostasis studies were performed. The patients were divided into four groups: vascular malformations (n = 115), inflammatory (n = 66), hemangiomas (n = 16), and controls (n = 47). Results. The incidence of local thrombotic events in patients with vascular and inflammatory diseases was higher (padj = 0.001 and padj < 0.001, respectively) compared with the control group and amounted to 20% and 31.8%, respectively. The median hospital stay for children with thrombotic events was 24 [16; 33] days, while the median stay for those without thrombotic events was 12 [8; 19] days (p < 0.0001). In cases of vascular malformations and inflammatory conditions, thrombodynamics revealed spontaneous blood clots in the samples. The growth rate and the size of the blood clots exceeded the reference values. Conclusion. It is imperative to conduct comprehensive monitoring of hemostasis parameters. Conventional blood clotting tests are inadequate for detection of early signs of hypercoagulability. Integral methods for monitoring hemostasis are effective for the early diagnosis of thrombotic events. The thrombodynamic test better reveals the hypercoagulation potential hidden from other methods at the preoperative stage. Regional thrombotic events in surgical oral and maxillofacial pathology have been demonstrated to result in a doubling of the length of hospital stay.

Introduction. The prevalence of acute and chronic liver diseases in pregnant women increases every year, which is associated with a high risk of adverse outcome for the mother and fetus. At the same time, the mechanisms that ensure an increase in uterine mass, structural changes in the myometrium before childbirth and the process of postpartum involution of the uterus to the initial mass, the participation of molecular cellular mechanisms in pregnant women with liver pathology, and ways to correct it remain poorly understood. Aim. The aim of the study was to investigate morphological changes in the myometrium, during pregnancy and the late postpartum period in the myometrium of mice with acute CCl4-induced hepatosis and under conditions of its correction with immobilized hyaluronidase. Materials and methods. The experiment was performed on 200 female pregnant mice of the C57B1/6 line at two months of age. Acute toxic hepatosis was modeled by a single injection of tetrachlormethane. Correction of acute hepatosis was performed on the next day after administration of tetrachloromethane and subsequent days of pregnancy with a single injection of immobilized hyaluronidase. The animals were divided into 4 groups: a group with physiological pregnancy, animals with the immobilized hyaluronidase drug injection; animals with acute hepatosis; animals with acute hepatosis treated with immobilized hyaluronidase. Uterine samples were collected on the 18th, 21st days of pregnancy and on the 1st, 5th, 10th, 15th days after delivery. Results. The volume density (Vv) of myocytes in the state of apoptosis, interstitial cytoplasmic conglomerates, which are products of clasmacytosis, and necrotized myocytes were calculated, as well as the numerical density (Nai) of myocytes with positive expression of the p53 protein. Under conditions of acute hepatosis, structural transformations of the myometrium in the form of an increase in clasmacytosis, necrotized myocytes occur already during pregnancy. The main structural mechanism of the process of postpartum involution of the myometrium of mice in conditions of acute hepatosis in the long-term period of postpartum involution was clasmacyto sis and, to a lesser extent, necrosis of myocytes. The processes of myometrial involution in mice under conditions of acute hepatosis slow down and do not complete by the 15th day of the postpartum period. When correcting acute hepatosis with immobilized hyaluronidase, the volume density of cytoplasmic conglomerates, apoptotically altered myocytes and necrotized myocytes decreases from the 1st to the 15th day of the postpartum period, which indicates the completeness of postpartum uterine involution. Conclusion. Liver damage is accompanied by a change in the metabolism of sex hormones, which leads to an abnormality of the mechanisms of postpartum involution of the uterus, as well as its structural changes before childbirth.

This study provides an overview of scientific results on the feasibility of using type III interferons against SARS-CoV-2. We have analyzed data obtained from the PubMed electronic database for the period 2020‒2022. The results of our own studies of pharmacological substances based on recombinant IFN-λ1 and its pegylated form are also presented. Completed and ongoing investigations allow us to position IFN-λ as an effective therapeutic agent against SARS-CoV-2.

Objective. To evaluate adherence to therapy in patients with hypertension (HTN) and atrial fibrillation (AF) in combination with extracardiac comorbid pathology. Design and methods. In an observational cohort study, 884 patients aged 45–65 years with AF (paroxysmal and persistent form) and HTN were observed, in combination with extracardiac comorbid diseases: diabetes mellitus (DM), n = 123; abdominal obesity (AO), n = 171; chronic obstructive pulmonary disease (COPD), n = 137, hypothyroidism, n = 156; thyrotoxicosis, n = 112. The comparison group consisted of 185 patients with AF and HTN, without concomitant extracardiac pathology. Clinical, anthropometric parameters, the Morischi–Green adherence test were evaluated in the work. To assess the social aspects of low adherence, special questionnaires were developed. All statistical calculations were performed using the Rstudio program. Results. Among patients with AF and HTN, 66 % had concomitant extracardiac comorbid pathology, 20 % of them with DM; COPD was detected in 22 % of patients, and AO was observed in 44 % of patients, 6 % patients had thyroid disease. 15,2 % patients were insufficiently adherent (ADH), 37,2 % were not adherent to therapy (NADH), and only 47,8 % respondents were adherent to therapy. The duration of HTN was not a significant motivation for adherence, because the NADH group had a significantly longer duration of arterial hypertension compared with the ADH group (12.3 vs 10.5 years; p < 0.03); patients with the permanent form of AF were more than ADH (p = 0,001), and the adherence did not differ between groups depending on extracardiac diseases. The blockers of the renin-angiotensin-aldosterone system showed the greatest use — up to 66 %, while adherent patients were more likely to take single-pill combination (SPC) of perindopril (SPC indapamide/perindopril and SPC amlodipine/indapamide/perindopril) (p = 0,003; p = 0,01). Based on the analysis, it was found that the presence of a family, higher education, income level, motivation and trust in doctors are significant factors that increase adherence to treatment. Conclusions. The problem of non-commitment has been and remains one of the most complex and difficult to solve. The main reason for low adherence among patients with AF with concomitant extracardiac diseases was polypharmacy, and it is associated with the use of a large number of drugs and a complex treatment regimen. Thus, the limitation of the use of fixed combinations is one of the main reasons for the lack of adherence and needs to be addressed soon.

The pharmacological activity of granulocyte CSF (G-CSF) immobilized using electron-beam synthesis nanotechnology (imG-CSF) was evaluated in an experimental model of ovarian reserve depletion. The effectiveness of the drug was compared with that of its unmodified form. Depletion of the ovarian follicular pool in female Sprague-Dawley rats was caused by a single intravenous injection of the antitumor drug etoposide in the maximum tolerated dose. The effectiveness of the studied drugs was assessed by serum concentration of anti-Mullerian hormone (AMH) measured by ELISA and by the number of primordial, two-layer, multilayer, and atretic follicles counted on serial sections of the ovaries (5-μm thick; through the entire organ) stained with hematoxylin and eosin. It was found that imG-CSF prevents depletion of the ovarian reserve in the model used, which was confirmed by high AMH concentration and higher numbers of primordial, two- and multilayer follicles in comparison with the corresponding parameters in the control (etoposide), and by a decrease in the severity of atretic processes. Unmodified form of the drug demonstrated lower efficiency.

The use of enzyme preparations is a traditional trend in various fields of medicine. The usage of immobilized enzymes hyaluronidase (IG) and subtilisin (IS) seems to be very promising for the treatment of damage to the ocular surface. The aim of the study was to establish the nature of changes in the ultrastructural organization of human conjunctival epithelium under the influence of immobilized hyaluronidase and subtilisin in vitro. Material and methods. In the experiment, a culture of normal cells of the human conjunctiva Chanqconjunctiva, clone 1–5 C-4, was seeded in 96well plates in the amount of 2 × 104 cells/well, after 24 h the medium was removed, Eagle’s medium MEM and fetal calf serum were added and cells were cultured for another 48 h. 5 experimental groups were formed: group 1 – without drugs (except for the composition of the incubation scheme), groups 2 and 3 – with IS at a concentration of 37 and 150 U/ml, respectively, groups 4 and 5 – with IG at a concentration of 37 and 150 U/ml, respectively. After preparation of cell preparations under a JEM 1400 electron microscope (Japan), ultrathin sections of 70–100 nm were studied at ×1000 magnification. Results. The article presents the results of electron microscopy of a culture of normal cells of the human conjunctiva in 5 experimental groups of cells with a description of changes in cytoarchitectonics under the influence of IG and IS. Conclusions. The introduction of immobilized enzymes into human conjunctival cell culture at a low dose (37 U/ml) affects the organization of cells without cytotoxic effects, while increasing the dose directly correlates with the occurrence of a cytotoxic effect.

Purpose: to study the regenerative potential of immobilized hyaluronidase and subtilisin enzymes preparations in experimental models of chemical and mechanical corneal trauma.Material and methods. The study involved 28 mongrel rabbits weighing 3.5 to 4 kg, divided into 4 groups for separate studies of repair models according to different types of injury (chemical vs. mechanical), and different drugs and the methods of administration thereof. Hyaluronidase (PEG-hyaluronidase) and subtilisin (PEG-subtilisin) pegylated by electron beam synthesis technology were used. The condition of the cornea was assessed 24 hours after the injury had been inflicted, whereupon the eyes were enucleated and histologically examined.Results. The chemical trauma groups treated by PEG-hyaluronidase revealed a decrease in the wound area by an average of 36.6 mm2, while those given a subconjunctival injection showed a 36.08 mm2 decrease. If PEG-subtilisin was applied, the area of the corneal defect revealed an average increase of 11.63 mm2 (with a case of perforation registered). In subconjunctival injection of PEG-subtilisin, the wound area decreased by 27.42 mm2. In the mechanical trauma groups, a similar pattern was observed: with the instillation of PEG-subtilisin, the wound area averaged 53.63 mm2 and 1 case of perforation was registered, whilst with subconjunctival administration, the wound area decreased to 28.76 mm2. With PEG-hyaluronidase instillations, a significant wound area decrease of 36 mm2 was noted, and with subconjunctival administration, the wound area decreased by 70.3%. A higher corneal transparency in the optical zone and a weaker inflammatory reaction with the use of PEG hyaluronidase were revealed by histological testing.Conclusion. A positive effect of PEG-hyaluronidase, specifically concerning the enhancement of regenerative processes in the wound in chemical and mechanical wounds could be seen. PEG-subtilisin showed no positive effects, which may be associated with high fibrinolytic activity.

Introduction. Under conditions of chemical damage to the cornea, its cellular structure is significantly disrupted, requiring emergency highly differentiated regeneration without an expressed proliferative component of inflammation and expansion of immunocompetent cells to gain an antimicrobial potential. For the purpose of pharmacological initiation of these processes, the study of the topical administration of anti-inflammatory enzyme preparations, such as subtilisin and hyaluronidase, is pathogenetically justified. Aim. To study the effect of hyaluronidase and subtilisin, PEGylated (polyethylene glycol – PEG) using the technology of electron beam synthesis on the number of immunocompetent cells in the area of the corneal chemical injury during their subconjunctival and topical administration. Materials and methods. An experimental study of the effect of PEGylated hyaluronidase and subtilisin enzymes, on the cellular composition of the corneal chemical injury was performed on 28 rabbits. Corneal injury was modeled using the Obenberger alkali burn technique. PEG-subtilisin or PEG-hyaluronidase was applied topically or subconjunctivally into the right eye of the animal, depending on the group, the left eye of the animal was used as a control – it was treated with 0.9% NaCl. After the experiment, enucleation was performed. The biomaterial obtained was used to prepare tissue specimens for morphological examination. Results. The total count of cells in the groups of topical and subconjunctival administration of PEG-subtilisin was 43 (40; 52) and 73 (33; 92), and subconjunctival injection of PEG-hyaluronidase – 46 (37; 61), which was higher than the count of cells when using 0.9% NaCl in these groups (p < 0.01) and higher (p < 0.0001) cell numbers in the group of topical administration of PEG-hyaluronidase. The total count of cells with topical application of PEG-hyaluronidase was 15 (13; 16), with topical application of 0.9% NaCl of this group – also 15 (14; 18) (p = 0.38). The neutrophil count with the use of PEG-subtilisin was 1 (1; 2) with topical and 0 (0; 1) with subconjunctival administration, and with the use of PEG-hyaluronidase – 0 (0; 0) both with topical and subconjunctival administration. Conclusion. The administration of PEG-hyaluronidase subconjunctivally and PEG-subtilisin both topically and subconjunctivally leads to an increased migration of immunocompetent cells to the area of the corneal chemical injury, while the migration of neutrophils is insignificant. It is completely absent when PEG-hyaluronidase is injected subconjunctivally. Topical administration of PEG-hyaluronidase does not induce a pronounced cellular response of immunocompetent cells in the area of the corneal chemical injury, and the effect of the application is comparable to that of 0.9% NaCl.

The development of safe drugs occupies a special place in the pharmaceutical industry. One of the main tasks of its preclinical phase is to evaluate possible toxic effects of the developed drug on the body and on various systems, including the immune system. The aim of our work was to study immunotoxic properties of pegylated hyaluronidase (PEG- HYAL). Material and methods. Mice F1(CBA/C57Bl/6) were divided into subgroups which were intragastric and intraperitoneally administered with PEG-HYAL in different dosages (50, 500, 1250, 2500 and 5000 U/kg). The number of antibody-producing cells in the spleen, the mass and cellularity of central and peripheral immune organs, phagocytic activity of peritoneal macrophages and neutrophils, delayed hypersensitivity reaction (DHR), level of hemagglutinin to sheep erythrocytes, spontaneous and mitogen-induced splenocyte proliferation were determined. Results. PEG-HYAL did not induce DHR, did not suppress phagocyte activity of peritoneal macrophages, at a dose of 50 ED/kg did not significantly affect the hemagglutinin content to erythrocytes, but at a dose of 500 ED/kg did statistically significantly reduce the titer of specific antibodies. When experimental animals were exposed to PEG-HYAL at doses of 50 and 500 U/kg, spontaneous and mitogen-induced proliferation of splenocytes decreased. Conclusions. The PEG-HYAL trial produced results that can be used to substantiate the administration of the PEG-HYAL-based medication.

Отличительной чертой новой коронавирусной инфекции (НКИ) COVID-19 является быстрое развитие коагулопатии с формированием тромбозов, которые поражают не только магистральные сосуды, но и систему микроциркуляции. Патогенез COVID-19-ассоциированных тромбозов многообразен и индивидуален. «Золотого» стандарта диагностики COVID-19-ассоциированных тромбозов в настоящий момент установить не удалось. Основным методом профилактики и лечения COVID-19-ассоциированных тромбозов является терапия антикоагулянтами. Нет надежных доказательств целесообразности применения антиагрегантов в комплексе мер тромбопрофилактики при НКИ COVID-19. Тромболитическая терапия является таргетным методом лечения COVID-19-ассоциированных тромбозов. В настоящий момент имеется опыт ее применения «off-label», проводятся клинические исследования, но клинические рекомендации по применению тромболитической терапии больных НКИ COVID-19 пока отсутствуют. COVID-19 is distinguished by the rapid development of coagulopathy associated with thromboses that affect both the main vessels and microcirculation. The pathogenesis of COVID-19-related thrombosis is diverse and individual, while the gold standard for its diagnosing has not yet been established. The main method for COVID-19-related thrombosis prevention and treatment is anticoagulant therapy. There is no reliable evidence for the use of antiplatelet agents in thromboprophylaxis for COVID-19. Targeted treatment in COVID-19-related thrombosis is thrombolytic therapy that is now used off-label. Clinical studies are being conducted; however, clinical recommendations for its use in patients with COVID‑19 are not yet available.

Introduction. Hyaluronidase is an enzyme preparation widely used in medicine, including ophthalmology. Hyaluronidase, having a protein structure, carries a potential danger in the form of undesirable allergic reactions. To avoid allergenic effects, protein structures are modified by combining with a polymer carrier, for example, by polyethylene glycol (PEG). Aim. To study the possible allergenic potential of hyaluronidase, PEGylated using the technology of electron beam synthesis, with various routes of administration. Materials and methods. The object of the study is PEGylated hyaluronidase (PEG-Hyal). Experimental animals are hybrid mice and guinea pigs. Seven types of experiments were carried out: anaphylactogenic activity; conjunctival challenge test; cutaneous applications; delayed-type hypersensitivity (DTH); active cutaneous anaphylaxis; indirect mast cell degranulation; inflammatory response to concanavalin A (ConA). Results. When studying anaphylactogenic activity, an anaphylactic reaction was not observed in guinea pigs. The conjunctival challenge test also revealed no signs of hypersensitivity to the drug. In the study of sensitization, no development of local allergic reactions was observed. In experiments to the study DTH in mice, there were no significant differences for the DTH index in the experimental and control groups. The assessment of active skin anaphylaxis has been showed that the diameter of the stained spot did not significantly differ in both experimental groups from the control one. In indirect mast cell degranulation experiments, it was found that there was no statistically significant change in the mast cell degranulation index. Evaluation of the allergenic potential of PEG-Hyal in the inflammatory response to ConA showed that there is no statistically significant difference between the experimental and control groups. Conclusion. Based on the results of the experiments, it can be concluded that PEG-Hyal does not have an allergenic potential in various routes of administration, which significantly expands the possibilities of its clinical use.

Introduction. Currently, a new pharmacological technology of thrombolytic therapy using immobilized subtilisins (ISs) has been introduced into clinical practice. Experimental and clinical studies have shown the high efficacy and safety of the treatment of thrombotic diseases using the drug Thrombovasim®, created on the basis of ISs. Although this drug has been widely studied as a thrombolytic, its pluripotent pharmacological properties have not been studied in detail. Aim. To study the performance of an isolated rat heart under the coronary perfusion with ISs. Materials and methods. The Langendorff’s perfused heart model was used in the study. The experiment included 50 Wistar rats. Animals were divided into 5 groups (10 animals each): group 1 – control (hearts perfused with Krebs-Henseleit solution) and 4 experimental groups – hearts perfused with ISs at 4 concentrations of 170, 340, 510 and 1020 IU/l respectively. The performance indicator of an isolated heart was assessed, reflecting the actual work of the heart muscle and expressed as the product of the heart rate and the strength of its contractions in the form of the pressure developed by the left ventricle. Results. No negative ISs effect on the performance of the isolated rat heart was found. A tendency to increase the performance in the first 5 minutes of using ISs was revealed. The achievement of the maximum and the duration of this effect depend on the ISs contents in perfusate. At a concentration of 170 IU/l, an obvious increase in the effect is found from the 10th minute, at higher concentrations – from the 5th minute. The duration of the increasing performance effect when using doses of 170–510 IU/l is maintained up to the 20th minute, when using ISs at a dose of 1020 IU/l – up to the 30th minute. The return of the performance indicators to the baseline values is observed at the 30th minute, at a dose of 340 IU/l – at the 40th minute. When perfused with a solution of ISs at concentrations of 510 and 1020 IU/l, by the 40th minute, the effect of increasing performance weakens, but the parameters still remain at higher levels as compaired to those at baseline. Conclusion. The experimental data obtained show that ISs increase the performance of the heart. This circumstance will allow expanding the use of the drug Thrombovasim® in a catastrophe of the coronary circulation.

The pharmacological experiments on isolated organs (ex vivo) are the preferred method for assessing the primary pharmacodynamics of the studied drugs, since this method is completely excluded the systemic influence of neurohumoral regulation. In the last decade, a new group of thrombolytic drugs based on immobilized subtilisins has been formed. At the stage of registrational preclinical and clinical studies, their pleiotropic pharmacological effects have not been studied. Meanwhile, there is a reason to consider that their pharmacological activity in the bloodstream is not limited to thrombolytic action, but may be extended to a systemic effect on the cardiovascular system. The aim of the study was to investigate the chronotropic effects of an isolated heart during its perfusion with solutions of immobilized subtilisins at different concentrations. Material and methods. The isolated rat heart model according to Langendorff was used in the study. The experiment included 50 Wistar rats, which were divided into 5 groups: isolated hearts perfused only with Krebs – Henseleit solution (control) or with immobilized subtilisins in 4 concentrations (170, 340, 510 и 1020 U/l). Results and discussion. The immobilized subtilisins have a negative chronotropic effect. The onset of the effect depends on the drug concentration in the solution: the higher concentration, the earlier effect. From 5 to 10 minutes of perfusion, a negative chronotropic effect is observed using of immobilized subtilisins at any dose. The duration of its increase is manifested up to 10–20 minutes, depending on the drug concentration in solution. After 20 minutes of perfusion, the achieved negative chronotropic effect remains at a plateau level up to 40 minutes. Conclusion. The immobilized subtilisins have an independent pharmacological effect on heart rate.