The coronavirus infection, COVID-19, caused by SARS-CoV-2 is associated not only with a wide range of respiratory syndromes, but also with a pronounced destructive effect on the blood vessels of the whole body. Age and concomitant pathology predispose to a more severe course of the disease. Endothelial damage, widespread vasculitis and thrombosis can be distinguished as general nonspecific pathomorphological changes developing in blood vessels under the influence of SARS-CoV-2. For the blood vessels of the lungs, in addition to alteration of the endothelium and thrombosis, angiogenesis of the cleaving (invagination) type was typical. The general mechanism of alteration of blood vessels and the development of vasculopathy is the direct cytopathic effect of the virus on endotheliocytes and immune-mediated damage to the endothelium, manifested by the development of endotheliitis, destruction of intercellular contacts of endothelial cells, their swelling and separation from the basement membrane, accompanied by endo- and perivascular inflammation. Molecular biological mechanisms of virus invasion involve various ways of its penetration into the cell and various forms of development of the inflammatory response with the participation of innate and acquired immunity reactions.

The aim of the study was to study pyramidal neurons and astrocytes of the hippocampal CA₃ region in dynamics in white rats after acute ischemia and severe traumatic brain injury.

Material and methods. Acute ischemia was simulated by 20-minute occlusion of the common carotid arteries (CCA), and severe traumatic brain injury (TBI) by a free-falling weight impact. The Nissl staining, hematoxylin and eosin staining, immunohistochemical reactions for NSE, MAP-2, p38, GFAP were used in the study. The proliferative activity of the cells was assessed using the Ki-67 response. The study was carried out on thin (4 μm) serial frontal sections in the animals of the control group (animals without pathological factors, n=5) in 1, 3, 7 and 14 days after the experimental modeling of CCA occlusion (n=20) and TBI (n=20). Morphometric analysis was performed using the ImageJ 1.52s software. The relative area of edema-swelling zones in the neuropil, the number density of pyramidal neurons, the content of dystrophic and necrobiotically altered neurons, the content of neurons with one or more nucleoli, proliferating cells, the density of large trunks of pyramidal neurons dendrites, the total number density and the relative area of giant synaptic terminals in stratum lucidum was detected. The distribution of variation series, the verification of statistical hypotheses, and the construction of graphs were assessed using the Statistica 8.0 software and the R.

Results. Mortality between groups did not differ and did not exceed 7%. In a day after CCA occlusion and TBI, there was a statistically significant increase in the relative volume of edema-swelling, the content of dystrophic and necrobiotically altered neurons, the total number density and the relative area of the terminals decreased, but the total number density of neurons did not change. In 3, 7 and 14 days, the mechanisms of neuroglio- and synaptic plasticity were activated. The content of neurons with two or more nucleoli increased, the total number and content of hypertrophied astrocytes increased, the cytoskeleton of damaged neurons was restored, and the content of interneuronal synapses increased. During the period from 3 to 14 days, the total number density of neurons in CCA occlusion decreased by 16.3%, and in TBI – by 33.7% (p=0.001). Pathological and compensatory-restorative changes were of a diffuse-focal nature and were more pronounced after TBI.

Conclusion. Thus, the same type of focal heterochronous and heteromorphic dystrophic, necrobiotic and compensatory-restorative changes in the nervous tissue were observed after CCA occlusion and TBI in the hippocampal CA₃ region. Structural and functional recovery occurred together with a decrease in the total numerical density of pyramidal neurons and edema-swelling of the nervous tissue. More pronounced dystrophic and necrobiotic changes in TBI were combined with more pronounced compensatory-restorative changes in astrocytes and giant interneuronal synapses of the hippocampal CA₃ region. The revealed changes were considered as the basis for the standard permanent compensatory-restorative reorganization of the nervous tissue of the hippocampus in the postischemic and post-traumatic periods.

The article highlights a complex of interendothelial connections of the lymphatic capillary of the rat intestinal villi, and focuses on the path of chylomicron transport through the lymphatic capillary wall after lipid loading.

Material and methods. An experimental model was used to exclude a high lipid load; chymus from do- nor rats was injected with a syringe into the initial section of the small intestine in 10 Wistar rats. Chymus was collected from the initial section of the small intestine of donor animals 60 min after oral administration of 1.5 ml of corn oil. The control group consisted of the animals exposed to 12-hour fasting. The material was studied using transmission electron microscopy.

Results. It was shown that most often cells are connected by tile-like (66±2.2%) or simple finger-like (27±2.4%) contacts, reinforced with a tight connection and a point adhesive (at the extreme point of contact). An- chor filaments located on the basal surface of endothelial cells at some distance from the extreme contact point “fixed” the lymphatic capillary wall, ensuring its stretching, changing the pressure inside the capillary and opening the valve. Under low lipid load, the main transport pathway of lipids from the interstitium of the intestinal villus to the lumen of the lymphatic capillary was through adhesive intercellular contacts. No chylomicrons were found in the lumen of plasmolemmal vesicles and kidneys. Caveolae in the endothelial cells of the lymphatic capillary, both after lipid loading and in hungry animals, were few. Caveolosomes were rare in both groups. Under low lipid load, no fusion of vesicles with the formation of transendothelial canals was found.

Conclusions. The detected structure of contacts of the lymphatic capillary endothelium morphologically substantiates the hypothesis of the regulated resorption of interstitial fluid and macromolecules into the lumen of the lymphatic capillary.

The article discusses the variability of the linear dimensions of the portal vein depending on gender and age. In modern foreign and Russian literature, there is no uniform information about the variant portal vein anatomy. Data on the extreme forms and on the range of anatomical differences in the portal vein vary considerably. All this requires the need for a more detailed study of the morphometric characteristics of the portal vein branch. Computed tomography, in contrast to dissection on a corpse, allows an in vivo study of various morphometric characteristics of the portal vein.

The aim of the study is to identify patterns of variability in the linear dimensions of the portal vein in persons of different sex and age.

Material and methods. The study material consisted of multispiral computed tomography images of the abdominal cavity with contrast enhancement taken in 100 patients. The study included results of 56 men and 44 women, divided into 4 age groups: 1) first mature age, 2) second mature age, 3) the elderly, 4) the senile. The length of the portal vein was measured between the angle formed at the junction of the superior mesenteric and splenic veins and the angle formed by the branches of the portal vein at the hepatic hilum. The diameter of the vessel was measured at the midpoint of the distance between the proximal and distal points.

Results. The length of the portal vein in the general sample was 66.45±8.49 mm, and its diameter was 11.84±1.93 mm. In women, the length of the portal vein was 64.37±6.6 mm, and its diameter was 11.33±1.83 mm, respectively. In men, both the length and diameter of the black vein were significantly greater than in women and constituted 68.09±9.4 mm and 12.24±1.91 mm, respectively. No statistically significant correlation of the studied parameters with age was detected.

The aim of the study was to detect the features of neurodystrophic changes in neurons and glia of the motor cortex of the brain in rats with different levels of cognitive functions and stress resistance with bilateral ligation of the common carotid arteries combined with short-term physical activity.

Material and methods. The study included 136 Wistar rats. All animals were divided into two subgroups depending on the results of testing in the Morris water maze: with a high and a low level of abilities for spatial environment learning. Animals of the experimental group were exposed to daily free swimming for 15 minutes, starting on the 7th and ending on the 35th days of the study. The rats were withdrawn from the experiment in 8, 14, 21, 35, 60, and 90 days after bilateral ligation of both carotid arteries. Histological sections of the precentral gyrus of the brain were stained according to Nissl and hematoxylin-eosin.

Results. On the 8th day of the experiment (1 day of short-term physical activity), the hemomicrocirculatory bed of the cerebral cortex was characterized by a decrease in venous hyperemia, and a decrease of tissue edema signs around the hemocapillaries, a characteristic feature of isolated cerebral hypoperfusion. Neurons with signs of hyperfunction and rod-shaped inclusions in the nuclei (Roncoronni bodies) were detected on the 14th, 21st, 28th days. Hemocapillaries formed compact groups of cells. Further, neurodystrophic changes were less pronounced in comparison with isolated cerebral hypoperfusion, this was accompanied by a decrease in venous hyperemia, preservation of perivasal cell groups up to the 60th day of the experiment. Roncoroni bodies disappeared on the 90th day of observation.

Conclusion. The effect of short-term physical activity on the development of cerebral hypoperfusion resulted in an increase in the number of neurons without irreversible changes, a decrease in neurodegenerative changes, and also reduced the severity of gliosis. The adaptive effect of short-term physical activity was more pronounced in animals with a high level of cognitive abilities, which was accompanied by a more significant decrease in the number of dead cells of the cerebral cortex. Day 28 was a critical point when gliosis and neuronal death were combined with the appearance of Roncoronni bodies and perikarion hypertrophy of some pyramidal neurons, as well as the concentration of gliocytes around hemocapillaries. The latter appears to be a sort of adaptation, since it is accompanied by a decrease in mortality in animals with a high level of cognitive abilities.

The aim of the study is to investigate the numerical composition and dynamics of structural and functional changes in prolactin cells of the anterior pituitary gland during reparative regeneration of long tubular bones.

Material and methods. The study included 40 Wistar rats. A transverse fracture of the middle third of the tibial shaft was simulated in the animals of the experimental group. Cells of the fracture area and the distal part of the adenohypophysis were studied using methods of light microscopy, immunohistochemistry and morphometry on the 1st, 3rd, 7th, 14th, 21st, 28th, 44th and 61st days.

Results. The study results demonstrated that in male rats of the control group, the percentage of prolactin cells in the adenohypophysis was 7.26±0.51%. During the fracture healing of the long tubular bone in rats, there were 2 stages of stress activation of the compensatory-adaptive potencies of the prolactin endocrinocyte adenohypophysis cluster with related changes in their structures: on the 1st–3rd days (the bone fracture effect on the body with the development of post-traumatic acute inflammation) and on the 14th–21st days (peak of chondroclast lytic activity with massive chondrolysis of cartilaginous callus).

Conclusion. Thus, the importance of prolactin as a stress mediator and the need for its participation in the regulation of stress metabolic changes are evidenced. At the same time, it becomes clear that with a pronounced acute stress effect; in this study it is represented by an open fracture, even the onset of a stress response can be manifested by a maladjustment of the lactotropic activity of the adenohypophysis, which is accompanied by an early "depletion" of its structural and functional reserves and a breakdown of compensatory-adaptive potencies right on the 1st day.

The aim of the study was to detect the age-related variability of the body mass index and the variability of fat deposition in a random sample of women belonging to different constitutional groups and somatotypes, permanent residents of the Republic of Karelia.

Material and methods. A comprehensive somatometric examination of women (n=905) was performed applying classical technique and a standardized set of instruments. The body mass index and its component composition were calculated using anthropometric formulas. I. B. Galanta – B.A. Nikityuk – V.P. Chtetsova technique was used to determine somatotype of the women. The results obtained were statistically processed using STATISTICA 6.0 program.

Results. The analysis demonstrated a high prevalence of overweight and obesity in women of the Republic of Karelia in the second mature and old age periods, which was manifested by the maximum values of the thickness of skin and fat folds, absolute and relative fat mass. Regardless of age, the megalosomal constitutional type was found with a high frequency, with an age-related increase in the proportion of people with the euriplastic somatotype. There were revealed somatotypological differences in the age dynamics of the body mass index and the content of the fat component in women. The values of the body mass index and fat component exceeding the norm were determined in the representatives of euriplastic and pyknic somatotypes over several age periods.

Conclusion. The results obtained can be used to analyze the level of physical development of the population, these findings should be taken into account when comprehensively assessing health, risk factors for metabolic diseases for their timely detection, correcting the diet, mode of nutrition, physical activity and providing population with preventive information.

The aim of the study was to evaluate the potential of miR-21 expression in the gastric mucosa as the marker of early stage gastric adenocarcinoma and cancer development.

Material and methods. The study included the following materials: the first group consisted of surgical material of 60 stomachs (gastric cancer of intestinal type), in each case, 1 fragment of tumor tissue and 4 specimens of the gastric mucosa of the distant zone (2 – antrum mucosa and 2 – fundal mucosa) were taken; the second group consisted of biopsy material of 62 cases in patients with chronic gastritis (5 specimens according to the OLGA-system protocol). The level of miR-21 expression in tissues was determined by reverse transcription polymerase chain reaction.

Results. miR-21 expression in samples with gastric cancer was significantly higher (median – 158, p=0.0006) compared with the group of endoscopic biopsies of the gastric mucosa (median – 42). The highest level of expression was observed in adenocarcinoma tissues (median – 270), while there were no significant differences when comparing it with the level of miR-21 expression in samples of the distant zone mucosa (p=0.2).тIncreased miR-21 expression may indicate the high risk group of developing gastric adenocarcinoma, probablyтbefore the appearance of histological signs of neoplasia.

Conclusion. Regression analysis performed to confirm the predictive potential of miR-21 expression demonstrated 13-fold increased risk of adenocarcinoma development associated with an increase in miR-21 levels for every 50 units of relative expression normalized to small U6 RNA. The constructed statistical model, which includes morphological criteria for evaluating the gastric mucosa and miR-21 expression, may reflect the degree of violation of cellular epigenetic molecular pathways and allows increasing the prognostic value of a biopsy investigation and the accuracy of a stratified assessment of the gastric adenocarcinoma risk development

The aim of the study was to comprehensively assess the structure of the knee joint in young men and men of the first period of adulthood with normosthenic constitution using the ultrasonography technique.

Material and methods. V.V. Bunak anthropometry technique (1941), B.A. Nikityuk and V.P. Chtetsov somatotyping (1990) and clinical examination of patients were used to form study groups, 25 people each with Pignet index from 17 to 23 without chronic diseases and pathology of the knee joint. Complex ultrasound examination was performed using ultrasound scanners "Sonoline G-60", Siemens (Germany), and Aloka 5500 Pro-Sound (Japan) with a linear transducer, 10 MHz frequency, and a convex transducer, 3.5 MHz frequency, in Ortho, Carotid and Abdomen modes with the "ZOOM" function. Morphometry was carried out using reference points. The obtained data were statistically processed by methods of variation statistics with a significance level of P≤0.05.

Results. There was detected a significant increase in the transverse and vertical dimensions of the condyles of the femur, and an increase in the thickness of the anterior and posterior cruciate ligaments in men of the first period of adulthood compared with the young men. The articular cartilage tended to restructure, this was manifested in thinning of its hypoechoic component and thickening of the hyperechoic component; the appearance of surface defects was more pronounced on the tibia. Ultrasound examination did not reveal age-related changes in the menisci of the knee joint, patellar ligaments and collateral ligaments.

Conclusion. Ultrasound examination of the knee joint in young men and men of the first period of adulthood allowed establishing age-related transformations of the condyles of the femur, cruciate ligaments and articular cartilage.

Mast cells cyclically synthesize and excrete a wide range of biogenesis products with different biological activities into the extracellular matrix and are regulators of local homeostasis both in normal conditions and in pathology – inflammation, oncogenesis, etc. The relative specificity of classical histochemical methods for detecting mast cells in relation to chromogenic to substrates causes certain difficulties in the selective study of the components of the secretome of mast cells, for example, heparin, histamine, chymase or tryptase. Therefore, immunomorphological techniques have become very popular, which identify specific substrates and allow differentiation of the components of the mast cell secretome. Mediators produced by mast cells promote neoangiogenesis, fibrillogenesis and re-epithelialization during the repair process.

The aim of our work was to study the tryptase profile of the mast cell population of rat skin during the wound processusing an original combined method of immunohistochemical staining.

Material and methods. The experiment involved 12 Wistar rats divided into two groups – intact (n=6) and with the existing wound process of the skin in the withers (n=6). The tryptase profile of mast cells was assessed on the 7th day of the wound process in comparison with the control group.

Results. The results obtained showed a significant increase in the number of tryptase-positive mast cells on the 7th day of the wound process in the skin against the background of a general increase in the population of mast cells. Intragranular tryptase reserve was significantly increased. In contrast to the control, where mast cells with single tryptase-positive granules dominated, during the wound process, cells of this type were practically not detected in the skin (43.69±2.9% and 8.55±0.9%). The content of tryptase-positive mast cells with complete filling of the cytoplasm in the control group and the group of animals with a wound process was 14.24±1.2% and 38.03±2.9%, respectively.

Conclusion. Thus, when modeling a wound, an increase in tryptase synthesis is detected both in individual MCs and within the entire MC population. This fact indicates that mast cell proteases can become a potential therapeutic target for improving wound regeneration by correcting immunogenesis, inflammation and fiber formation.

Relevance. The currently available methods for measuring anatomical areas with irregular relief do not claim to be accurate and easy to use.

The aim of the study was to develop a method for measuring the surface area of an anatomical region (substructure) with an irregular relief.

Material and methods. There was developed an option to measure the surface area of an anatomical region (substructure) with a complex relief in patients with pathology of the maxillofacial region and perineum using realistic 3D modeling.

Results. The principle of the developed method is that, firstly, it is necessary to determine the patient's "zone of interest", where it is planned to measure the surface area; after that, digital photographs of the defined area are taken to obtain a sufficient number of images from the maximum number of available angles using a template with predefined dimensions for scaling. Then the obtained photographs are processed in the program for the 3D model reconstruction, and a realistic 3D model that correctly repeats the relief of the "zone of interest" and guarantees measurements of the surface area taking into account all its individual features is obtained. The method has been tested in obstetrics and gynecology, dentistry, maxillofacial surgery.

Conclusion. This technique has been proved to be simple, accessible, fast, highly accurate in measuring the area of anatomical regions with complex relief. At the same time, the investigated object does not need fixation and prolonged immobility. A digital optical device is used contactless, the fact being significant in situations where it is necessary to comply with the rules of asepsis and antisepsis.

The article provides data on scientific research of the Moscow scientific school of academicians D.A. Zhdanov and M.R. Sapin in the field of morphofunctional organization of the lymphatic and immune systems. The historical materials and scientific research of their students and followers were studied. The biographical milestones in the life and professional activities of Academician of the USSR Academy of Medical Sciences D.A. Zhdanov and his student, academician of the RAS M.R. Sapin within the walls of the I.M. Sechenov First Moscow State Medical Institute (now – Sechenov University). The main scientific direction of D.A. Zhdanov taught about the lymphatic system. As a result of his research, the important role of the organs of the immune system in the formation of the body's response to antigenic effects was shown. Studying the professional and creative activities of M.R. Sapin showed that he was a fairly bright personality in the morphological community. A large number of his students and followers allows the scientific direction of academician M.R. Sapin live and develop today. New scientists-morphologists, using modern research methods, will continue and develop the teachings of M.R. Sapin, as in his time he continued and deepened the scientific direction of his teacher.

The article is dedicated to the anniversary date, the 210th anniversary of the birth of the genius of Russian medicine, doctor and surgeon, anatomist and teacher, an outstanding citizen and ardent patriot of Russia – Nikolai Ivanovich Pirogov. On November 25, 2010, on the day of the 200th anniversary of the scientist, a memorial plaque was installed at the Department of Operative Surgery of the Academy, made in the Urals at the expense of cadets and being the only material monument in our country that reminds of this event. The article describes the
life path and stages of scientific activity of N.I. Pirogov, his contribution to science and the unconditional significance of his work for the development of clinical medicine and morphology. The international scientific conference “Pirogov's Legacy: Past, Present, Future”, held in November 2010, was a major event in the scientific life of many department teams of the Military Medical Academy and became a memorable part of the anniversary scientific events of St. Petersburg dedicated to the great scientist and organized by the Pirogov Surgical Society and the medical community of the city. This article presents the scientific works of N.I. Pirogov, which can rightfully be considered fundamental in the formation of modern morphology and medicine.

The article is dedicated to the anniversary of Nikolai Nikolaevich Shevlyuk, Doctor of Biological Sciences, Professor, Honored Worker of the Higher School of the Russian Federation. The main stages of the life path and scientific achievements of the jubilee are described. His fundamental works in the field of ecological morphology, morphogenesis and regeneration, taxonomy and nomenclature, history of science and medical education are presented.