Megakaryocytopoiesis under hypoxic conditions

Acute and chronic hypoxia led to acceleration of proliferation and differentiation of bone marrow megakaryocytes and increase in their functional activity. The count of young cells in the peripheral blood increased during acute hypoxia. Chronic hypoxia led to increase in the number of old platelets with lower functional activity, which was accompanied by thrombocytosis.

Modulation of reparative regeneration and CD117 expression by liver cells after partial hepatectomy in mice

The effects of 3-aminophthalhydrazide and carrageenan on reparative regeneration and expression of CD117 by liver cells after partial hepatectomy were studied in mice. 3-Aminophthalhydrazide stimulated regeneration of the liver and increased the count of CD117(+) hepatocytes. By contrast, carrageenan inhibited liver reparation and CD117 expression.

Hemoglobin heterogeneity under conditions of abnormal erythropoiesis

Experiments on rats showed that changes in the hemoglobin profile during hypoxia are determined by switching of erythropoiesis from the "basic" to "emergency" mode. The "basic" mode of erythropoiesis is typical of the mature organism under normal conditions. The "reserve" or "emergency" mode is realized in fetuses, senile animals, and during hypoxia. This mode is characterized by production of large erythrocytes with high content of fetal hemoglobin.

Changes in Erythropoiesis during Liver Regeneration after Partial Hepatectomy

Changes in erythropoiesis during liver regeneration after partial hepatectomy depended on functional activity of phagocytosing mononuclear cells.

Mechanisms of changes in the hemoglobin profile during acute adaptation to extreme conditions

We studied changes in rat hemoglobin isoforms during acute adaptation to various hypoxic conditions. Erythrocytes were heterogeneous in the content of various hemoglobin isoforms. Changes in the hemoglobin profile during hypoxia are related to variations in the ratio between populations of erythrocytes differing in the content of individual hemoglobin isoforms.

Reaction of CD117+ cells to renal lesion under conditions of phagocytic mononuclear system stimulation

The content of CD117(+)cells in the kidneys and CD45(low)CD117(+)cells in the bone marrow and blood of mice were studied after partial nephrectomy and under conditions of macrophage stimulation with 3-aminophthalhydrazide. The counts of tubular CD117(+)epitheliocytes sharply increased and the content of CD45(low)CD117(+)cells in the bone marrow decreased after renal damage. Injection of 3-aminophthalhydrazide stimulated the expression of CD117 by renal epitheliocytes and led to reduction of CD45(low)CD117(+)cell counts in the bone marrow and blood. Macrophages stimulated proliferative processes in the kidney and differentiation of stem cells in the bone marrow due to synergic effects of their cytokines and stem cell factor.

The Blood-Brain Barrier in Neuroimmune Interactions and Pathological Processes

The blood-brain barrier (BBB) is a kind of filter, highly selective in relation to various types of substances. The BBB supports the immune status of the brain and is an important regulator of neuroimmune interactions. Some of the molecular and cellular features of the BBB, as well as the five main pathways of neuroimmune communication mediated by the BBB, are analyzed in this article. The functions of the BBB in neuroimmune interactions in various diseases are discussed: multiple sclerosis and Alzheimer's and Parkinson's diseases. The latest data on BBB dysfunction in COVID-19 coronavirus infection caused by the SARS-CoV-2 virus are considered.

NFLUENCE OF MAST CELLS ON REPARATIVE REGENERATION OF TISSUES WITH DIFFERENT DEGREE OF IMMUNOLOGICAL PRIVILEGES

It is assumed that tissues with different degree of imminological privileges have a number of distinctions in the processes of reparation. This may be associated with mast cells, which are found in all body tissues of an organism, secrete a wide range of biologically active substances and are important in the regulation of repair processes. This paper present the results of investigations of morphometric parameners and functional activity of mast cells in tissues with varying degrees of immune privilege (skin, testis). It has been shown that migration of must cells in the skin is observed early after the injury and followed by a slow increase of synthetic activity and index of degranulation of mastocytes within 30 days. Index of degranulation of mast cells in the testes increased immediately after the injury in the absence of their pronounced migration. Stabilizing membranes of mast cells using the drug ketotifen led to inhibition of the repair of the skin, which was manifested itself in the absence of increasing the thickness of dermis, epidermis, the number of fibroblasts and collagen fibers, and also in slowing down the formation of scar. At the same time, the inactivation of mast cells promoted reparative regeneration of testes as was indicated by increase in the number of normal spermatogonia which are proliferative pool for all subsequent stages of spermatogenesis, and by considerable decrease in the number of non-functioning tubules. Thus, the number and the functional sate of the mast cells have an impact on the course of reparative processes in tissues with varying degrees of immune privileges.

[Sex Differences in Behavioral Reactions and the Character of Audiogenic Seizures in Krushinsky-Molodkina Rat Strain]

In the "open field" test it was found that locomotor activity in Krushinsky-Molodkina rat strain (KM) is higher than in nonlinear animals. At the same time, both groups of animals had the same sex differences: a locomotor activity of females was higher than males. Sex differences in exploratory activities are not inherent for KM rats, while the female outbred animals are significantly higher than males in their level of such activities. The greatest differences in behavior between KM rats and outbred animals were found in anxiety level, which is much higher in the first case. Furthermore just KM rats are characterized by clear sex differences--the males demonstrate more anxious and fearful respond to unfamiliar surroundings than females. Male and female KM rats differ not only in behavior but also in the character of epileptiform seizures induced by loud sound: wild running, tonic-clonic and clonic convulsions occur faster in females and the resumption of breathing-in males. The interconnection between parameters of seizure and behavior was found for KM rats. This phenomenon is most clearly manifested in males and combine large group of indicators.

[The clotting tests and molecular markers in evaluating of coagulation alterations against the background of anti-thrombotic prevention by Dabigatran after large orthopedic operations]

The large orthopedic operations are associated with high risk of development of thrombosis of deep veins of lower extremities. Nowadays, new oral anticoagulants are widely applied for anti-thrombotic prevention. The coagulation alterations against the background of effect of Dabigatran, a direct inhibitor of thrombin were examined in 30 patients underwent endoprosthesis replacement of knee joint. The routine clotting indices, fibrinopeptid A, soluble fibrin-monomeric complexes, D-dimer. The samples of blood were selected before operation, after 30 minutes, and at 1st, 3d, 7th and 14th day after endoprosthesis replacement of knee joint. It is demonstrated that routine clotting tests and also detection of D-dimer and soluble fibrin-monomeric complexes provide no adequate evaluation of coagulation activity in patients underwent large orthopedic operation. The concentration of specific marker of fibrin formation of fibrinopeptid A continues to be increased no less than two weeks after endoprosthesis replacement of knee joint that testifies keeping hyper-coagulation and risk of thrombosis. The intake of Dabigatran etexilate in fixed dosage does not exclude development of thrombosis of deep veins of lower extremities that substantiates point of view concerning usefulness of individualization of anti-thrombotic prevention in case of application of new oral anti-coagulants.

System of hemopoiesis and morphogenesis

Method of transplantation of hemopoietic cells is proposed for acceleration of recovery of damaged tissue structures. The morphogenetic effect of transplantation depended on the state of damaged tissue and was determined by not only hemopoietic stem cells, but also lymphocytes, macrophages, and mast cells.

[Feasibility of using connective tissue prosthesis for autoplastic repair of urinary bladder wall defects (an experimental study)]

Experiments on laboratory rats have shown the feasibility of autoplastic repair of urinary bladder wall defects using a connective-tissue capsule formed as the result of an inflammatory response to the presence of a foreign body. The formation of connective tissue prosthesis is characterized by developing fibrous connective tissue, ordering of collagen fibers, reducing the number of cells per unit area with a predominance of more mature cells - fibroblasts. With increasing time of observation, connective tissue prostheses were found to acquire a morphological structure similar to that of the urinary bladder wall. By month 12, the mucosa, the longitudinal and circular muscle layers were formed. The proposed method of partial autoplastic repair of urinary bladder wall is promising, has good long-term results, but requires further experimental studies.

The Possibility of Using Bioprostheses for Autoplasty of Skull Bone Defects (an Experimental Study)

The possibility of obtaining a connective tissue bioprosthesis on a cellulose implant placed under the skin and its further use in cranioplasty was demonstrated in experiments on rats. A positive dynamics of bone tissue formation on the basis of the obtained bioprosthesis was revealed.

Role of functional activity of phagocytic mononuclear system in the formation of autoprostheses for angioplasty

The possibility of formation of connective-tissue vascular prostheses on subcutaneously implanted polychlorovynil base was demonstrated in experiments on rats. Suppression of the function of phagocytic cell with carrageenan decelerates, while its stimulation with tamerit accelerates the formation of connective-tissue autoprostheses.

Hemoglobin Isoforms in Rat Erythrocytes in Acute Aseptic Inflammation

Qualitative rearrangement in erythropoiesis (changes in the ratio between erythrocyte populations and hemoglobin isoforms) was revealed in male Wistar rats with modeled acute aseptic inflammation. It was found that the percentage of heavy hemoglobin isoforms prevailed over the light forms in the bloodstream. Deciphering of the mechanisms of these changes requires additional research.

[Gender differences in the pool of free amino acid neurotransmitters in Krushinsky-Molodkina rats]

The study of the role of neurotransmitter systems in the pathogenesis of epilepsy is one of the priorities of epileptology. New data on the functions of free neurotransmitter-like amino acid in the central nervous system are of the greatest importance and determine the prospects for the development of novel effective anticonvulsants. It is widely believed in clinical medicine that epilepsy has distinct gender characteristics. The aim of this study was to investigate the gender peculiarities in the content of neurotransmitter amino acids in the brain of Krushinsky-Molodkina (KM) rats, which were used as model organisms for the study of genetically induced audiogenic epilepsy. The content of Asp, Glu, GABA, Gly, and Tau of the medulla oblongata, hippocampus and cerebral cortex were determined using high-performance liquid chromatography (HPLC) in intact KM rats, KM rats exposed to a series of epileptiform seizures, and Wistar rats (control group). Both the Wistar and KM rats had gender distinctions in the distribution of free amino acids among the investigated brain parts. The audiogenic epilepsy was characterized by smoothing gender differences as well as differences between the concentrations of free amino acids in the cortex and medulla oblongata, specific for Wistar rats. The changes observed in male rats after the set of seizures included the increase in GABA concentration and a decrease in the Gly level in all investigated brain parts, as well as the decrease of the Tau content in the cortex and hippocampus. At the same time, the Glu content in cortex increased, while the Asp level decreased. After 6 days of audiogenic stimulations the female KM rats demonstrated the increase in the Glu level in all investigated brain parts, the increase in Gly and Asp levels in hippocampus, and no changes in the GABA content. Thus, after the set of epileptiform seizures the KM rats achieved a new steady state of the studied amino acids pool, which differed in males and females. In this case, gender differences significantly changed after the seizures.