In this review, we pay attention to the role of the hypoxia-inducible factor (HIF) in the development of response of the organism to hypoxia. Special attention is given to the regulation of the cell responses to hypoxia in chronic peripheral artery disease in patients with diabetes mellitus (DM). Cells can survive by activation of a transcription of genes, involved in angiogenesis, glucose metabolism and cell proliferation. Artificial rising of concentration and activity of HIF stimulates an angiogenesis and improves ulcers healing of the lower extremities. The data of the literature are provided on the possible methods of increasing HIF concentration in tissues, which could be a new way to stimulate wound healing in the patients with DM.

The data about use of color Doppler method to study the characteristics of eye blood flow in the preterm infants with retinopathy of prematurity (ROP) are presented in the review. The greatest attention is paid to arterial blood flow examination, and there are only single studies about venous blood flow in ROP. The results presented in different sources indicate on color Doppler informativity in the diagnostics of ROP, however, they are ambiguous and contradictory. It points to the necessity for the further studies on generalization and systematization of the eye blood flow characteristics in the disease, and also on recognition of the most useful indicators for assessing the severity of the pathological process, predicting its course and determining of the optimal management and treatment tactics for patients with ROP.

Objective. To study the influence of diet containing high or normal NaCl on the arterial blood pressure level (BP), heart rate (HR), processes of myocardial remodeling and of nuclear transcription factor kB (NFkB) expression in myocardium and kidney in spontaneously hypertensive rats (SHR). Design and methods. The two groups of male SHRs received a diet with normal (0.34 %; n = 24, control) and high content of NaCl (8.0 %; n = 25; experimental group) for 2 months. Blood pressure (BP), heart rate (HR), cardiac left ventricular mass index (LVMI), left (LKMI) and right (RKMI) kidney mass indexes were determined. Morphological study of myocardium (light microscopy), including quantitative morphometry was carried out. In part of animals the relative level of NFkB gene expression in heart and kidney tissues was studied. Results and discussion. In rats fed a diet containing 8 % NaCl BP and HR did not change significantly compared with the control. However, LVMI, RKMI, LKMI were significantly higher in high-salt diet-treated animals than in controls. The heart of high-salt diet-treated animals developed the changes leading to hypertrophy and possibly hyperplasia of cardiomyocytes. In these animals, perivascular fibrosis, significant increase of arterial wall thickness and vacuolization of smooth muscle cells were revealed. The relative level of NFKB gene expression in rats receiving high-salt diet was 33-fold higher in myocardium and 12-fold higher in kidneys than in animals fed a normal salt diet. Conclusion. The high-salt diet is not necessarily accompanied by an increase in blood pressure, but causes myocardial remodeling, apparently due to direct «toxic» effects. The negative impact on the cardiovascular system of high-salt diet is in part mediated through NFkB-associated signaling pathways. Furthermore, high NaCl diet causes activation of NFkB in the kidneys.

Objectives. Our objectives were to study the effect of Notrombel administration (one of the representatives of a new class of compounds, N, N'-substituted piperazines) on the development of experimental thrombosis. Material and methods. Thrombosis of the femoral artery was induced in Wistar male rats by 30-minute laser irradiation (532 nm, 60 mW, irradiation area - 1 mm²) after intravenous injection of Rose Bengal A (17 mg/kg). The blood flow was recorded by high-frequency ultrasonic dopplerography (20 MHz) before irradiation and every 10 minutes after irradiation. Notrombel and Acetylsalicylic Acid (ASA) were administered intravenously (control - 0.9 % sodium chloride) and intragastrically (control - water) in increasing doses. Results. Thrombosis of the femoral artery developed in all control animals during 30-minute laser irradiation. With a single intravenous administration, Notrombel was more effective than ASA (100 % prevention of thrombosis at doses of 0.0045 mM/kg and 0.05 mM/kg, respectively). The calculated effective dose (ED50) for Notrombel was about 0.0021 mM/kg, and for ASA - 0.029 mM/kg. After seven intravenous administrations of Notrombel, no cumulative effect was observed (a single dose ED50 = 0.0021 mM/kg), in contrast to ASA (ED50 = 0.0032 mM/kg). After seven intragastric injections, the antithrombotic activity of the drugs was close (for Notrombel ED50 = 0.0049 mM/kg, for ASA 0.0041 mM/kg). Conclusions. With a single intravenous injection, the antithrombotic activity of Notrombel (ED50 = 0.0021 mM/kg) is higher than that of ASA (ED50 = 0.029 mM/kg). With the course of intragastric and intravenous administration, the effects of the drugs are comparable. Unlike ASA, Notrombel had no cumulative effect, which indicates the safety of repeated parenteral administrations of the drug.

Bioelectrical activity is a universal characteristic of functional state of the brain at a normal level of blood flow and under hypoperfusion. This parameter can be used to assess the effectiveness of the operation before and after endarterectomy. In this study we analyzed spectral characteristics of EEG in 106 patients who underwent endarterectomy in the acute period of stroke before and after two weeks from the onset of the disease. Was studied the dynamics of the power spectra of the EEG evoked potentials and clinical data before and after surgery. It is revealed that the nature of the change in the spectral power of alpha and beta activity of the EEG in the affected and in the intact hemisphere in acute ischaemic stroke can affect the timing of carotid endarterectomy and are important for the prediction of functional outcome after surgery. Inhibition of alpha- and beta-activity in both hemispheres in the preoperative period is an unfavorable factor for surgical intervention, as this will not lead to restoration of disturbed functions irrespective of stroke severity.

Introduction and purpose of the work. Peripheral blood circulation in arterial hypotension is poorly understood. The results of the available data are contradictory. The aim of the study was to evaluate the structural and functional parameters of peripheral arteries and veins in idiopathic arterial hypotension in young women. Materials and methods. 72 women with idiopathic arterial hypotension and SBP level of less than 98 mm Hg at the age of 18-22 years were examined. Results were compared with the blood flow parameters of 37 women of similar age with normal arterial pressure (SBP 120-129 mm Hg). During angioscanning, the diameter and velocity indices of the blood flow of the vertebral, brachial, radial, posterior tibial arteries and the respective veins were studied. Results. A decrease in blood flow rate in the brachial and posterior tibial arteries, as well as in the brachial and posterior tibial veins was revealed. Differences in diameters of arteries and veins between women of the two groups were not revealed. Conclusions. Idiopathic arterial hypotension (SBP < 98 mm Hg) in young women is characterized by a lower blood flow rate in the peripheral arteries and veins than in women with normal arterial pressure.

The aim of the work is to reveal patterns of changes in blood flow fluctuations due to autonomic tone in patients with acute systemic cold injury (ASCI) in hypothermic period. Materials and methods. 45 patients aged 18 to 45 years (3 groups of 15 patients with mild, moderate and severe cold trauma) were examined in the hypothermic period. The control group included 15 healthy volunteers. The subjects studied in the groups did not differ in gender, age and body weight. Microcirculation was assessed in all patients on admission using non-invasive laser doppler flowmetry (LDF). Results. In the study of perfusion and blood flow oscillations, it was established that the PM and σ values were increased in patients with mild degrees of ASCI relative to the control group, decreased in severe ASCI, and were not different from controls in moderate degree of ASCI. The parameters of Kv, A_max (H), and A_max (M) in patients with mild and moderate degree of ASCI did not significantly differ from the control group; however, in patients with acute intravascular coagulation, there was a marked increase in these parameters in comparison with the control group and with mild and moderate intensity ASCI. The A_max (C) index did not show any difference in ASCI of mild and moderate degree relative to the control group, however, its decrease was noted in patients with a severe degree of ASCI compared with the control group and with mild and moderate degree of ASIDC. When studying the vibrational component of sympathetic regulation of blood vessels, it was established that the parameters of the normalized maximum amplitude A_max (H)/σ and A_max (M)/σ were decreased in patients with mild degree of hypothermia relative to the control group, increased with severe hypothermia and did not have a statistical difference with controls in moderate degree of ASCI. Conclusion. The hypothermic period of ASCI of mild degree is accompanied by a decrease in the vibrational component of sympathetic regulation of the vessels. In the hypothermic period of the moderate degree of ASCI, there is no pronounced change in the amplitude of the neurogenic regulation of the vessels. Severe degree of ASCI in this period is accompanied by a significant increase in blood flow fluctuations due to sympathetic regulation.

Objective. The aim of the study was to analyze the time derivative of temperature response of finger phalanges to brachial occlusion and to establish the relationship between the parameters of temperature dynamics and hemodynamic parameters. Materials and methods. To analyze the response to the occlusion, the methods of dynamic thermography and photoplethysmography (PPG) were used. The parameters of the temperature reaction on occlusion in a group of 60 healthy subjects were analyzed. The Shitzer model was used to establish the relationship between temperature dynamics and peripheral hemodynamics. Results. Parameters describing the temperature response of the fingers on occlusion were introduced. It is shown that the time to reach the maximum of the temperature derivative during post-occlusion corresponds to the maximum of the volumetric blood flow. A coefficient of symmetry is proposed that characterizes the curve of the hemodynamic response of the extremity vessels to a sharp restoration of blood flow after removal of the occlusion. The parameters of temperature dynamics paralleled to the changes in hemodynamic parameters. Conclusions. To compare the results of temperature measurements and results of optical methods of blood flow estimation it is advisable to use not the temperature signal but its first derivative. The use of temperature parameters, expressed in degrees, creates the conditions for the development of a quantitative approach to the description of the hemodynamic response to occlusion. The results of the study contribute to the development of noninvasive methods of diagnosing endothelial dysfunction as a harbinger of atherosclerosis.

Introduction. Critical limb ischemia (CLI), which arises from atherosclerotic lesions of the arteries is quite often presently. This problem is actively discussed all over the world. In addition to the disability of the patients due to limb loss, the death rate from this disease is comparable to mortality from malignant tumors. Objective. Evaluate immediate and long-term results and optimize treatment tactics for patients with critical limb ischemia in multilevel lesions of lower limb arteries. Materials and methods. The examination and treatment of patients with CLI was carried out in the Research Institute of Surgery and Urgent Medicine of the First State Medical University of Saint-Petersburg named by I. P. Pavlov, as well as on the basis of the City Clinical Hospital «City Hospital No. 14» and St. Petersburg Research Institute of Emergency Care named by I. I. Dzhanelidze in the period from 2005 to 2016. The study is conducted in patients with atherosclerotic lesion of the main arteries of the lower extremities, which manifests itself as pain at rest and/or tissue loss (stage 3-4 of chronic arterial insufficiency of the limb according to Fontein-Pokrovsky classification). Results. Clinical success of all kinds of interventions was achieved in 166 (88.8 %) patients. However, the negative results were greater in the group where only angioplasty of the lower limb arteries was performed. Long-term results could be traced in 108 (57.8 %) patients for 6 months - 5 years. If we consider all groups as a whole, then the aggravation of ischemia occurred in endovascular intervention group in 62 % of patients, in the group of bypass operations - in 19.61 %, and in the group of hybrid interventions - in 17.65 %. Conclusion. Hybrid methods of treatment are the method of choice for patients with stage 4 ischemia of the lower limb with multilevel lesions of lower extremity arteries. Open surgery on the arteries of the lower extremities remains a very effective method of treating patients with critical ischemia. In turn, the use of endovascular methods is advisable in patients with severe concomitant pathology.

Introduction and aim. Bispectral index (BIS) and heart rate variability (HRV) can be monitored in real time, along with the standard hemodynamic parameters: blood pressure (BP) and heart rate (HR). It is interesting to assess the interrelationship between these parameters during anesthesia. In this work, the objective was to evaluate the changes of HRV, depending on the level of sedation for outpatient endoscopic procedures and to develop a mathematical model of their relationship. Materials and methods. In the first phase of the study, comparative and staged assessment of hemodynamic parameters, BIS and HRV was performed in 26 patients, including 11 men and 15 women aged from 18 to 74 (46±14) years. In the second stage, in order to test the operability of the model, the study was conducted in 12 patients aged from 20 to 72 (44±15) years. All patients were subjected to endoscopic surgery (colonoscopy). The assessment of HRV, hemodynamic profile, and the BIS was carried out in three stages of the study. Depending on the BIS values, all patients were allocated to three levels of sedation. Results and discussion. As a result, the models for HRV-based BIS determination were obtained, giving a high degree of objectivity in determining the status of anesthesia in patients based on HRV-derived BIS. Conclusions. The results of the study revealed the parameters that together reflect the level of sedation. Suggested mathematical model based on discriminant analysis allows to assess the level of light sedation with accuracy of 85.7 %, and the level of adequate sedation with accuracy of 93.3 %. The accuracy of a classification matrix was 89.1 %. The developed software allows to visually assess the level of sedation.

The limiting role of the cardiovascular system when performing sports loads is associated not only with central hemodynamics, but peripheral mechanisms, regulating blood flow. One of the indicators playing a significant role is a velocity of capillary blood flow. Using the method of high-frequency ultrasound dopplerography, the study of blood flow characteristics in a microvasculature at rest and after exercise session was conducted in 53 adolescents at the age of 9-15 years with different sport experience. During these studies it was found that background blood flow velocity values in the arteriolar and capillary bed (p≤0.05) are higher, and vascular tone is lower in adolescents of 14-15 years and adolescents having a longer sport experience, compared with adolescents of 9-13 years. Blood flow indicators in a microvasculature of the older age group are closer to the values recorded in adults. Various mechanisms aimed at maintenance of muscle oxygenation during exercise, are revealed after exercise session. It is confirmed visually (on the dopplerogram) and quantitatively that mechanisms increasing blood flow to muscles are activated at less-trained adolescents (9-13 years old) during exercise. More efficient mechanisms are observed at the older age group: redistribution of blood flow and increase in number of functioning capillaries.