Pericytes were discovered about 150 years ago and their name can be translated as enveloping cells. The location of pericytes on the outer wall of capillaries, the presence of appendages and close contact with neighboring endothelial cells of the capillaries resulted in the hypothesis of their participation in the capillary blood flow control. Over the last years, a large number of publications confirming this hypothesis have appeared. Moreover, the data accumulated to date indicate that pericytes are multifunctional cells and play a significant and sometimes key role in such processes as regulation of tissue blood flow, functioning of the blood-brain barrier, angiogenesis, vascular remodeling, and immune responses. The participation of pericytes in the pathogenesis of certain diseases has been shown and the potential for their use as targets for therapeutic effects has been demonstrated.

Introduction. Ultrasound imaging allows us to study the influence of topographic and anatomical variability of the main vessels of the neck on hemodynamic parameters in the area of bifurcation of the common carotid artery (CCA). Aim. To assess the significance of changes in hemodynamic parameters on the damage of the main arteries near the bifurcation of the common carotid artery in different variants of the mutual position of vessels according to the results of ultrasound Dopplerography. Materials and methods. 865 volunteers were examined using SonoAce R7 and Logiq F6. The results were summarized, systematized and processed in Microsoft Excel 2007 spreadsheets and subjected to statistical analysis. Among the participants, 5 main variants of the mutual position of the vessels were identified: A – typical; Б – the external carotid artery (ECA) is located ventrally; В – the lateral position of the external carotid artery; Г – divergence or intersection of the carotid arteries near bifurcation; Д – joint medial deviation of both carotid arteries. Results. A total of 1730 vascular complexes were evaluated. The smallest diameter of the external carotid arteries was observed in groups A and B – 3.10 mm. The largest value of the diameter of the internal carotid arteries (ICA) was in group D – 4.20 mm and in group B – 4.10 mm. The diameter of the common carotid arteries in groups A and B was 5.50 mm, in groups D and D – 5.60 mm, and in group B – 5.70 mm. The volume velocity of blood flow had higher values in group D. The lowest indicators of volumetric blood flow velocity were noted in group A, for common carotid and internal carotid arteries – in group G. Conclusions. The smallest average and median diameter of the external carotid arteries was observed in types A and B. The highest median diameter of the internal carotid arteries was in group D (4.20 mm). The median value of the diameter of the common carotid arteries was the maximum in group B (5.70 mm). The presented observation results demonstrate the effect of anatomical variation on the morphometric and functional characteristics of the vascular bed, reflecting the change in the calculated volumetric velocity of blood flow.

Introduction. Changes in the hemostasis and fibrinolysis system in patients with aortoiliac segment lesion can cause the development of specific thromboembolic and hemorrhagic complications, accompanied by a high level of mortality. Preoperative laboratory analysis of the D-dimer blood level may help to objectify the risk assessment of open surgery in this category of patients. Objective. Assessment of the significance of preoperative blood D-dimer level in predicting the development of morbidity and mortality after open surgery on the aortoiliac segment. Materials and methods. The study included 108 patients who were determined the D-dimer blood level before planned reconstructive intervention on the aortoiliac segment at the Pavlov University from 2013 to 2021. The first group consisted of 56 patients with aneurysmal aortoiliac segment lesions, and the second group included 52 patients with occlusive-stenotic lesions of the aortoiliac segment. Results. 92 (85%) patients had an increase of D-dimer level above 500 μg/L, among them 18 patients developed early postoperative complications, and 4 cases were fatal. In 16 (15%) patients with normal D-dimer levels, the postoperative the period was uneventful. Both groups showed statistically significant differences in preoperative blood D-dimer levels depending on the presence or absence of early postoperative complications. In the first group, the median of D-dimer level in the smooth course of the postoperative period was 2035 μg/L, and in patients with complicated course – 3770 μg/L (p=0.04), in the second group these indicators were 635 μg/L and 1231.5 μg/L (p=0.02), respectively. The threshold value of D-dimer level in predicting the risk of death in the first group was 4150 μg/L (p=0.001). Conclusion. The blood D-dimer level may be an additional laboratory risk factor for adverse outcome of open surgery in patients with aortoiliac occlusive disease.

Introduction. Joint hypermobility syndrome (JHS) is characterized by a multisystem lesion of organs, including the cardiovascular system, which determines the presence of cardiovascular risks in this pathology. Aim. Studying of arterial stiffness and endothelial dysfunction parameters in patients with JHS. Material and methods. Study population included 105 adults with JHS (90 women and 15 men) and 57 healthy controls (49 women and 8 men) aged 20 to 28 years (mean age 22 [21; 23] years). All persons underwent a general clinical examination; examination of endothelial vasomotor function (EVF) and pulse wave velocity at the carotid-radial segment (PWVcr) by rheography (IMPECARD-M, Belarus); investigation of arterial stiffness parameters: cardio-ankle vascular index (CAVI), cardio-ankle pulse wave velocity (PWVha), ankle-brachial index (ABI), augmentation index (AI) by sphygmography (VaSeraVS-1500N Fukuda Denshi, Japan); determination of T786C polymorphism of the eNOS gene by polymerase chain reaction (Litech, Russia), determination of endothelin-1 and transforming growth factor beta-1 (TGF-β1) levels by enzyme immunoassay (Fine Test, Wuhan Fine Biotech Co., China). Results. According to the main clinical and laboratory indicators, the groups were matched. In patients with JHS, the values of PWV at the carotid-radial and cardio-ankle segments were higher, in other parameters (EVF, CAVI, ABI, AI) the groups were matched. In the group with JHS, pathological values of EVF, PWVcr, CAVI, AI were more often determined. Among patients with JHS, an excess of vascular age over the passport age is detected 8.6 times more often (95% CI from 1.103 to 67.321). These changes are not associated with mutations of the eNOS T786C gene and changes in endothelin-1 and TGF-β1 concentrations. Conclusion. These data indicate the importance of further study of the mechanisms of early vascular changes in the arteries in JHS, in order to develop optimal methods of therapy and improve the cardiovascular prognosis of patients with this pathology

Introduction. COVID-19 causes generalized endothelitis and impaired arthriolo-venular circulation leading to a slowdown in blood flow and venous hypervolemia. This leads to decompensation of the drainage function of perforated veins and the occurrence of horizontal venous reflux. Aim. To determine the possibilities of surgical correction of decompensated forms of chronic venous insufficiency (CVI) in patients after COVID-19, when determining the localization of pathological venous reflux by ultrasound duplex scanning of the lower extremity veins. To determine the character of microcirculatorydisorders in the examined patients. Material and methods. Ultrasound duplex scanning with a 7.5-10 MHz linear sensor was performed in 59 patients aged 40-78 years, 34 women and 25 men who had suffered from COVID-19 in a moderate form that did not require hospitalization. Patients had not previously noted manifestations of CVI and did not use diosmin drugs. The reason for treatment was the manifestation of complicated forms of CVI, which first appeared after COVID-19. 39 patients of group I underwent surgical correction of horizontal venous reflux, 20 patients of group II received conservative treatment. The microcirculatory bed was examined using a high-frequency ultrasound Dopplerograph on the nail bed of the 1st finger of the upper limb with a 25 MHz sensor. Results. The revealed microcirculatory disorders were characterized by a depletion of the Doppler spectrum, which corresponds to parietal stasis. Isolated horizontal venous reflux was recorded in the area of trophic disorders: pigmentation, induration and trophic ulcers (TU) of the shin. In group I patients, as compared to group II, pain syndrome, edema, induration and inflammation significantly decreased after treatment when assessed by the VCSS scale. More rapid and complete healing of TU was observed. Conclusions. COVID-19 provokes accelerated progression of isolated horizontal venous reflux, due to generalized microcirculatory disorders reported in patients in the post-COVID period. The surgical intervention for its elimination in the nearest future after applying undoubtedly surpasses conservative methods of treatment and allows achieving a good cosmetic and clinical result.

Introduction. Vasospasm and delayed cerebral ischemia (DCI), which develop after rupture of cerebral arterial aneurysms and their surgical treatment, are serious complications that worsen the clinical outcome of the disease. The ability to predict the risk of developing these complications is an urgent task allowing to reduce neurological deficits and improve the quality of the patients’ life after aneurysm rupture. Aim – to develop a prognostic model for the development of DCI in patients with ruptured cerebral arterial aneurysms based on the study of a complex of clinical manifestations and a number of laboratory parameters. Material and methods. We examined 91 patients with ruptured arterial aneurysms and the development of subarachnoid hemorrhage in the acute period, identifying the main group with the development of DCI (n=67) and the comparison group without DCI (n=24) in the pre- and postoperative periods. Clinical neurological and neuroimaging studies have been carried out. We studied indicators of blood oxygen transport function, platelet aggregation, coagulogram, concentration of nitrates/nitrites (NOx), angiotensin-converting enzyme (ACE) in venous blood in the pre- and postoperative periods. Results. Based on the logistic regression equation, we determined that predictors influencing the probability of DCI development after aneurysm rupture and clipping include a score on the Glasgow Coma Scale (p=0.001), the p50 value is the partial pressure of oxygen in the blood at which hemoglobin is oxygen saturated by 50% (p=0.001), ACE concentration (p=0.013), NOx/ACE index (p=0.001) and the degree of platelet aggregation according to Traptest (p=0.005). The threshold value of the result of the logistic regression equation was 0.58 with a diagnostic sensitivity of 85.4% and specificity of 69.3%, the area under the ROC of the AUC curve was 0.88±0.015 (p<0.001), which indicates the high quality of the constructed model. Conclusion. The developed predictive model of the probability of DCI development in patients with ruptured arterial cerebral aneurysms with a diagnostic efficiency of 88% allows timely identifying patients for whom it is advisable to begin neuroprotective therapy before surgical treatment.

Introduction. In preeclampsia (PE), the hemostasis system, including the platelet component, changes significantly. The purpose of the work was to identify the peculiarities of the morpho-functional characteristics of platelets in women with early and late PE. Material and methods. The main group consisted of 26 women with early PE and 46 women with late PE. The control group consisted of women with normal pregnancies without hypertensive disorders, of whom 17 were at a gestational age of 260–336 weeks and 42 were at a gestational age of 340–394 weeks. The ADVIA 2120i hematology analyzer was used to evaluate platelet concentration (PLT), platelet distribution width (PDW), mean platelet volume (MPV), concentration of large platelets (Large PLT), percentage of large platelets from the total number of platelets (%LP), mean platelet component concentration (MPC), mean dry platelet mass (MPM). Results. Women with early PE have increased PDW, MPV, LargePlt, %LP and MPM indices compared to women with normal pregnancies up to 34 weeks. Female patients with late PE had lower PLT and higher PDW, %LP, MPC, MPM compared to women with normal pregnancies after 34 weeks. In late PE, PLT is reduced and PDW, %LP and MPM are increased compared to early PE. Conclusion. The detected changes in platelet indices in women with PE, regardless of the period of its onset, indirectly indicate increased thrombopoiesis and high functional activity of young platelets. However, the mechanisms that increase platelet activation in early and late preeclampsia differ.

Introduction. Atherosclerotic lesions of the lower extremity arteries often have a multilevel character, the consequence of which is the disability of the population up to the development of post-ischemic necrosis. Conventional methods of surgical treatment of occlusion of the superficial femoral artery (SFA) and multilevel arterial lesions, however, are characterized by high traumatism causing an increase in mortality in this cohort of patients. Overcoming the above disadvantages required the development of alternative approaches, particularly hybrid revascularization. Objective. To analyze our own experience of the above-mentioned intervention in order to further evaluate its benefits. Material and methods. The study included 80 patients suffering from chronic limb-threatening ischemia (CLTI) with occlusion of the femoral-popliteal segment arteries >20 cm long. The subjects were divided into two equal groups depending on the type of surgery performed – autovenous femoral-popliteal bypass with endovascular correction of outflow channels (hybrid bypass) or autologous femoral-tibial bypass (FTB). We analyzed the clinical and demographic characteristics of the patients, technical features of interventions, as well as their direct and long-term effects. The assessment of the shunt patency was carried out using Kaplan-Meyer tables. The differences in indicators between groups were determined using the logarithmic criterion. Results. Thirty-day mortality among patients in the hybrid bypass group was 2.5% versus 4.3% in the second group (p>0.05). The frequency of graft failure is 5% versus 13%, respectively. A year after the operation, the primary shunt patency reached 77.7% (95% CI 61.7-93.7) in the first group. In the second group, this indicator was 57.1% (95% CI 42.9-71.3). One-year survival without amputation was 82.1% (95% CI 66.8-97.4) versus 69.6% (95% CI 56.1-83.1), respectively. The frequency of angiosomal revascularization in patients who underwent hybrid bypass surgery reached 90.0%. In the other group, the indicator was lower and amounted to 69.2% (p=0.006). Conclusions. The presented information proves the high efficiency of the investigated method of treatment.

One of the effective methods of artery and vein occlusion used in experimental studies and in clinical practice for certain diseases is local exposure of vessels to high-intensity focused ultrasound (HIFU). The wide use of this method in our country is limited by the lack of appropriate domestic equipment. At the Peter the Great St. Petersburg Polytechnic University, in the Laboratory of Ultrasound Technologies of the Center for Advanced Research, a stand for HIFU effects on various biological objects has been developed. There is no experience in using this device in angiology yet. The purpose of our research was to study the possibility of using Medusa 008, a high-tech mobile medical device designed for ultrasound diagnosis and personalized HIFU therapy, to model vascular occlusion and stop blood flow during irradiation. Materials and methods. The object of the study is the femoral artery of a rabbit. The source of HIFU is Medusa 008, the high-tech mobile medical device designed for ultrasound diagnostics and personalized HIFU-therapy with radiation frequency of 2 MHz (prototype). The following irradiation modes were used in the research: irradiation duration - 50 ms, pause between exposures – 10 ms, number of pulses – 20, 30, 40. The following energy values corresponded to these modes: 58 J, 87 J, 116 J. Irradiation of the femoral artery of an anesthetized rabbit was performed percutaneously. We used ultrasound to visualize the arteries and measure the blood flow velocity. According to ultrasound data, after HIFU irradiation, blood flow in the artery stopped. The factor contributing to arterial occlusion is the cessation of blood flow during irradiation. A histological examination of the area of the irradiated artery revealed structural changes in all layers of the vascular wall. Results. HIFU irradiation with intensity of 87 and 116 J has a significant dose-dependent destructive effect on the muscular arterial wall. The more intense damaging irradiation (116 J) causes smooth muscle cell necrosis. The time of direct influence on the vessel wall structures did not exceed 3 sec. During the experiment, we found that HIFU in the used modes causes temperature increase up to 45–60 ^оC, which is enough for thermal damage of cells in the irradiation zone. Conclusion. Thus, as a result of the above experiments, it was shown that Medusa 008, the high-tech mobile medical device designed for ultrasound diagnostics and personalized HIFU-therapy can be used to simulate vascular occlusion.

Bacterial lipopolysaccharide (LPS) plays a leading role in the development of a systemic inflammatory response and endogenous intoxication. However, the sex differences in the functional state of the microcirculatory bed in LPS-induced endotoxinemia have been poorly studied. Objective. To study the characteristics of skin microcirculatory vascular reactivity in experimental LPS-induced endotoxinemia in male and female rats. Material and methods. Modeling of endotoxinemia was performed by intraperitoneal injection of LPS of the cell wall of the bacterium Salmonella enterica to male and female Wistar stock rats. Two doses of LPS were used: 50 mg/kg and 10 mg/kg. We used laser Doppler flowmetry to evaluate skin perfusion before and after LPS injection, blood flow changes under test conditions with local contact hypothermia caused by a thermoelement. Results. 48 hours after LPS injection, a decrease in blood flow was observed, especially pronounced at a dose of LPS 50 mg/kg. During the test with local cooling of the skin, a change in the kinetics of the reaction was noted. Blood flow reduction was 75% (LPS 50 mg/kg) and 51% (LPS 10 mg/kg), statistically significantly different from the control groups. At the same time, the classic phenomenon of “cold vasodilation” observed in control rats was absent in all groups with the injection of LPS. Maximum perfusion after restoration of blood flow in females was achieved 3 times faster than in males (LPS 10 mg/kg). Conclusion. In experimental LPS-induced endotoxinemia, a dose-dependent decrease in skin perfusion was revealed. We obtained new data on the absence of pronounced “cold vasodilation” at local contact hypothermia. The results of the study indicate a violation of the mechanisms of neurogenic vasoconstriction and endothelium-dependent vasodilation, reflecting systemic disorders of microcirculation regulation. At the same time, the females showed a more positive dynamics of blood flow restoration in the test with local cooling of the skin, indicating a greater functional reserve and a more effective mechanism of autoregulation of the blood microcirculation system. A functional test with local contact cooling of the skin is highly informative for assessing vascular reactivity and preservation of the autoregulation mechanism of microcirculation in modeling endogenous intoxication

Objective. To determine the character of changes in the reactivity of rat periodontal microvessels depending on the multiplicity of zoledronic acid administration. Material and Methods. Wistar rats (n = 36) were divided into groups of 9 rats each. In group No. 1 (control), rats were injected with 0.9% sterile sodium chloride solution once a week for 3 weeks; in group No. 2, rats were injected once with zoledronic acid (ZA) once a week; in group No. 3, rats were injected intravenously with ZA once a week for 3 weeks; in group No. 4, rats were injected with ZA once a week for 6 weeks. ZA was administered at a dose of 0.18 mg/kg in 0.9% sterile sodium chloride solution in the volume of 1 ml/kg. The microcirculation parameters in the periodontium were determined before ZA administration and on the 3rd day after administration by laser Doppler flowmetry (LDF) and ultrasound high-frequency dopplerography (UHFD) methods. Periodontal vascular reactivity was determined using acetylcholine assay. Results. After ZA administration, the indices of microcirculatory vascular reactivity decreased in rats of groups No. 3 and No. 4 in comparison with the results obtained before ZA administration: at ultrasound examination the maximum increase of blood flow velocity was noted at the 2nd minute and amounted to 133±8,5, 112±7,8 %, respectively. In rats of group No. 2, the increase in blood flow velocity corresponded to the value of the control group. In LDF study, the maximal blood flow rates were lower than in the control group in rats administered the drug for 3 and 6 weeks, respectively. Conclusion. Zoledronic acid dose-dependently causes impaired vascular responsiveness and leads to a decrease in endothelium-dependent vasodilation.

The problem of maintaining the health at the proper level in elderly and senile patients is becoming more and more urgent from year to year. This relevance is quite understandable, since a detailed study of this topic will improve the quality of life in a predominantly vulnerable category of citizens. It is well known that aging is a physiological process that affects all organs and systems of the body without exception. However, in our opinion, the most significant problem is age-related changes in the brain, since nothing reduces the quality of life of elderly patients so much as dysfunction of the central nervous system (CNS) structures. The article presents a review of the literature, which highlights modern ideas about the blood-brain barrier (BBB) and its impact on age-associated changes in nervous tissue.