Currently, preeclampsia is one of the most significant problems in obstetrics and gynecology. The significance of this pathology is determined by its high prevalence and pathological impact on the organism of both mother and fetus. The pathogenesis of preeclampsia is very complex, involving many different interrelated, complementary pathophysiological and biochemical reactions. One of the main mechanisms of preeclampsia development is the excessive synthesis of antiangiogenic factors that, among other effects, contribute to increased activity of a number of substances with vasoconstrictor action. These changes lead to the formation of placental insufficiency and the development of clinically overt disease. Among the most important substances that contribute to the formation of excessive uncontrolled vasospasm are endogenous digitalis-like factors (EDFs) which regulate the activity of Na+/K+-ATPase. The most important structural class of EDFs is represented by bufadienolides. The classic representative of this group is marinobufagenin. It selectively blocks the α-1 isoform of Na+/K+-ATPase, widely represented in the renal tubules thereby having the properties of potent.

The review focuses on the application of methods of mathematical modeling in the study of the mechanisms underlying the formation of low-frequency oscillations in the human cardiovascular system. The main emphasis is put on 0.1 Hz rhythms and related author’s works. New ideas about the fundamental role of the hydrodynamic properties of the vascular bed in the formation of low-frequency oscillations at the frequency of 0.1 Hz are presented and justified.

Aim – to investigate the patterns of cutaneous microcirculation and their relationship with structural vascular changes in palmar hypoderm in patients with Dupuytren’s disease.

Material and methods. In 26 patients with Dupuytren’s contracture aged between 45 and 70 years, the microcirculation of palmar skin was assessed before the planned surgical treatment using ultrasound pulsed Doppler (Minimax-Doppler K, SP Minimax, St. Petersburg, Russia) with a high-frequency sensor of 20 MHz and laser Doppler flowmetry (BLF21, Transonic Systems Inc., USA). The local 3-minute arterial ischemic test was performed in all patients by putting the occlusion cuff on the forearm. Histological analysis of intra-operative tissue specimens was done using light microscopy (Carl Zeiss Primo Star microscope with 3.1 MP UCMOS video camera) MicroCapture Ver 6.6 program was used for data acquisition.

Results. The normocirculatory type of hemodynamics (1) was found in 17 % of observations; hyperemic (2) – in 19 %, congestive-spastic (3) – in 42 %, and congestive-static (4) – in 21 %. Histologically type 1 was characterized with initial signs of constrictive arterial remodeling and capillary occlusion, 2 – with marked hyperemia of the microcirculatory bed and diapedesis of blood cells, inflammatory perivascular infiltrates, 3 – with significant narrowing and deformations of lumens in small arteries and hyalinosis of arterioles, 4 – with pronounced polymorphism of capillary loops, significant changes in arteries and veins.

Discussion. Hyperemic type of microcirculation reflects high activity of autoimmune inflammation. Congestic-spastic type indicates a significant decrease in the reactivity of precapillary microvessels. Congestic-stasic type is accompanied by the most pronounced constrictive vascular remodeling and denervation of the vascular bed.

Conclusion. Dupuytren’s contracture is characterized with predominance of pathological types of microcirculation in palmar skin, which must be taken into account in individualized protocols of additive therapy. 

Purpose – the study the nonlinear dynamics of microcirculation parameters in human symmetrical organs.

Material and Methods. Parameters of microcirculation were measured in healthy volunteers (aged between 50 and 70 years) by means of laser Doppler flowmetry (LDF). LDF signal transducers were fixed symmetrically on the lower parts of the right and left shoulders (3 cm above the elbow bend). The degree of chaoticity of microcirculation parameters as a nonlinear dynamic process was estimated using Hausdorff’s index, relative entropy and characteristics of phase portraits. Along with components of the amplitude-and-frequency range for blood flow fluctuations (myogenic, neurogenic, respiratory, and cardiac) was estimated and correlations between all characteristics of microcirculation in both sides of the body were done.

Results. Asymmetry of correlation relationships of nonlinear dynamics parameters and components of the amplitude-andfrequency range for blood flow fluctuations of right and left sides of the body was revealed. Hausdorff index in the left side correlated not only with the average value of perfusion and with the coefficient of variation in the same side (r1 = –0,68; r2 =–0,51), but also with correlation dimension of chaos in the opposite side (r=0,49). Similarly, entropy in the left side correlated not only with the average value of perfusion and coefficient of variation in the left (r1 =0,43; r2 =0,60), but also with the entropy and correlation dimension of chaos in the right side (r1 =0,48; r2 =–0,41). The neurogenic component in the left side positively correlated with the myogenic component in the same side (r=0,71). A positive correlation was observed between the neurogenic component in right side and myogenic component in the opposite side (r=0,57). Asymmetry of correlation relationships was also revealed for the respiratory and cardiac components.

Conclusions. Our results illustrate the specific regulation of blood flow in micro vessels of paired organs, which is associated with functional asymmetry. The physiological mechanisms for this asymmetry require further experimental and clinical studies. 

Aim – to investigate the relationship between the values of the carotid endothelial shear rate and ultrasound morphology of atherosclerotic plaques in carotid arteries.

Material and methods. The study involved 70 patients with carotid atherosclerosis, including 43 males and 27 females. The average age of patients was (61.1±8.54) years. All patients underwent ultrasound triplex scanning of carotid arteries. Ultrasonic plaque morphology was evaluated using several ultrasonographic characteristics: uniformity of echotexture and echogenicity. We used the classification of G. Geraulakos et al. (1993). Endothelial shear rate in the common carotid artery was determined in accordance with the law of Hagen – Poiseuille.

Results. Most patients (30) had a plaque type I, less frequently occurred plaque II (15) and III (20 patients) types. Homogeneous echo positive plaques corresponding to «stable» phenotype were found in 5 patients. In patients with plaque type I and II, endothelial shear rate values were 373 (305; 481) s–1 and 311 (282; 419) s–1 respectively. In the groups of patients with plaque– type III and IV endothelial shear rate was significantly higher – 500 (429; 556) s–1 and 470 (440; 512) s–1 respectively. Among patients with plaque with a predominance of echolucent component, more patients with type 2 diabetes mellitus were found (p=0.006).

Conclusion. Carotid endothelial shear rate was significantly lower in patients with carotid atherosclerosis and echolucent plaques compared to those having predominantly hyperechoic plaque. Prevalence of diabetes mellitus type 2 was significantly higher in the group of patients with unstable plaque and low carotid endothelial shear rate. 

Using the thermography method, we studied the state of the upper limbs of 43 patients with Raynaud’s disease, 37 of which were operated as a result of dynamic observation in the process of conservative treatment. A directly proportional relationship between the thermal imaging pattern and the treatment method of microcirculatory disorder in the distal sections of the upper limbs has been revealed. It is established that visualization of the contour of fingers at the level of distal phalanges may result in both conservative and surgical treatment – upper thoracic sympathectomy or distal periarterial and thoracic sympathectomy in combination with finger amputation. Taking into account the received data, we confirmed that the use of a thermographic study with computer data processing in the diagnosis of the pathological process of the upper limbs is a method of selecting the principle of treatment (conservative or surgical).

The results of a comparative study of the linear velocity of blood flow in the arteries of the bone regenerate in patients with fractures of the leg and shoulder bones and in the process of Ilizarov treatment are analyzed. Studies were conducted at rest and when performing a number of functional tests (orthostatic, muscular and with a dosed axial load on the limb). The effect of stress on the state of regional and cerebral blood flow in the conditions of inpatient treatment and after the transfer of patients to the outpatient treatment regimen was assessed.

Material and methods. 41 adult patients with a closed diaphyseal fracture of the humerus and 57 patients with a fracture of the tibia bones during Ilizarov treatment were examined. The blood flow in the regenerate and along the middle cerebral arteries was determined by the method of ultrasonic doppler sonography.

Results. With an increase in the functional load on the limb in patients with fractures of the humerus and tibial bones, respectively, up to 10 and 30 kgf, a temporary increase in the blood flow velocity in the arteries of the bone regenerate was observed. Large values of the load on the lower leg, accompanied by the acceleration of blood flow, indicate a better protection of the vascular bed of the tibial regenerate. The magnitude of the decrease in blood flow velocity in the regeneration of the lower leg arising from the behavior of an orthostatic test in the course of treating patients increased from 21 to 37 %, and indicated an increase in the reactivity of the vascular bed. In patients with injuries of the shoulder and lower leg, the transfer to the outpatient treatment regimen was accompanied by a statistically significant (p≤0.001) increase in the duration of the fixation period, respectively, to 82±3 and 94±7 days, a decrease in the increased blood flow velocity in the middle cerebral artery on the contralateral side by 43 % and 57 % and an increase in the magnitude of changes in cerebral blood flow rate during functional muscle test by 50 and 67 %. 

Intraoperative bleeding impairs visualization of the surgical field. Working in a practically bloodless operating field reduces the duration of surgery and reduces the need for cautery use, which reduces pain in the postoperative period and the risk of delayed bleeding after tonsillectomy.

Objective – to select the parameters of a diode laser with a wavelength of 970 nm in order to get optimal hemostatic effect and to develop a technique for safe preventive coagulation of vessels in the surgical wound using diode laser with a wavelength of 970 nm for their bloodless section.

Materials and methods. 47 Wistar rats weighing 300–400 g were used in the experiment. After preparation of the surgical field, three groups of vessels were isolated from each rat. The rat vascular bed was used as a model of tonsillar vascular bed in the patients undergoing tonsillectomy. All animals were divided into groups, depending on the laser power. For the experiment we used a diode surgical laser with a wavelength of 970 nm in a constant mode, a fiber diameter of 400 microns. After coagulation of each vessel, a visual and microscopic assessment of the vessels was performed. The study of the possibility of vascular coagulation was evaluated after the vessel was cross-sectioned with a scalpel.

Results. Damage to the walls of blood vessels was not observed at powers from 5.0 W to 7.0 W. At the same time, at the laser power from 5.0 W to 6.0 W there was no hemostasis after crossing the vessels. At a power of 6.5 W, adequate hemostasis was observed only in 42 % of cases. The coagulation mode of a diode laser with a wavelength of 970 nm, which is the most effective and safe for surrounding tissues, was observed at a power of 7.0 W

Conclusions. Exceeding the power levels of a diode laser with a wavelength of 970 nm leads to the formation of carbonization of the surrounding tissues, to a damage of the vascular wall. In order to prevent bleeding, arteries with a diameter of more than 1.5 mm must be stitched. Small vessels with a diameter of less than 0.4 mm do not require preventive coagulation and can be coagulated during the incision with a laser fiber.

Introduction. Ischemic injury to the endothelium influences on a coagulation hemostasis, worsening hemodynamics of cerebral microcirculation as a result of rheological occlusion. The long-term post-ischemic blood clotting system changes are not studied well by now.

The work purpose – to study a coagulation hemostasis and endothelial prostacyclin – synthetic activity of pial vessels within 21 days after single short-term transient cerebral ischemia in rat.

Material and Methods. Ischemia was reproduced by means of 12-minute time occlusion of both carotids with the simultaneous arterial hypotension. Post-ischemic changes were investigated in 4 groups of rats: on the 3rd, 7th, 14th and 21st day after ischemia. The state of blood clotting system was estimated on time of clot formation in the blood plasma by an automatic optical method with use of screening tests of definition of prothrombin and thrombin clotting time and concentration of fibrinogen. Endothelial prostacyclin – synthetic activity was estimated by pial vessel reaction to indometacin.

Results. On the 3rd day after ischemia the increase in prothrombin time was observed. Level of fibrinogen increased on the 3rd and the 14th days of the post-ischemic time. On the 21st day after ischemia thrombin time decreased. The inverse correlation of pial vessel endothelial prostacyclin – synthetic activity with the fibrinogen level and direct correlation with vessel cross-sectional area of these vessels is established.

Conclusions. Short-time global cerebral ischemia causes changes of blood clotting system mechanisms lasting for 21 days of the post-ischemic time. Post-ischemic abnormalities in hemostasis system are connected with changes in endothelial prostacyclin – synthetic activity of cerebral vessels that, along with decreased anti-aggregation ability of vascular system, is also the reason of narrowing of the lumen in pial vessels. 

Retinal vein occlusion was described 160 years ago; however, some pathogenesis aspects of the disease remain controversial at present.

The aim – to study the characteristics of the photoinduced retinal vein occlusion with the aim of developing of pathogenetically based method for its treatment.

Material and methods. The experiment was carried out on 60 rabbits. 40 animals were subjected to photoinduced retinal vein occlusion with the «Photoditazine» injection and laser irradiation of blood vessels. The retinal veins massage with the scraper’s silicone tip was made on 20 intact animals. The 40 rabbits with photoinduced retinal vein occlusion were divided into 2 equal groups: the main group, which received massage of the obturated retinal vein, and the comparison group, which were injected with 500 international units (IU) of recombinant prourokinase.

Results. In experimental photoinduced occlusion of retinal veins, the forming thrombus in the vessel caused microcirculation disorders with the development of retinal edema, plasmorrhagias and hemorrhages. Affected retinal vein massage accelerated resorption of retinal edema by1.5 times and accelerated the lysis of hemorrhages by 2.0 times compared with epiretinal fibrinolytic injection, without causing a damaging effect on the vessel. In animals of the main group, according to optical coherence tomography, edema of the retinal central parts decreased by 1.5 times. According to fluorescent angiography, the time of retino-vein perfusion decreased by 2.6 times compared with epiretinal injection of prourokinase.

Conclusions. Experimental studies have confirmed the safety and effectiveness of retinal vein massage for the treatment of occlusion of central retinal vein and its branches. Massage of the retinal veins contributes to the rapid reversal of pathological changes in the retina during mechanical action on the wall of affected vessel with subsequent restoration of its patency. 

The aim – to investigate the effect of photoactivated coproporphyrin III (KP III) on microcirculation in the rat mesenteric vascular bed. Material and methods. The study was performed on 20 male rats, divided into 4 groups: 1) control; 2) KP III; 3) laser irradiation; 4) laser irradiation on combined with prior administration of the KP III.

The object of the study was venules (20–40 µm) of the mesentery of the small intestine. The study of blood flow velocity in the venules was performed using the method of intravital biomicroscopy. The velocity parameters were registered using a high-speed video camera Basler acA2000 (Germany). Coproporphyrin III (Elast, Russia) at a dose of 10 mg/kg was injected into the tail vein 3 hours before laser irradiation. Irradiation was performed using a Lakhta Milon semiconductor laser apparatus (Qualitek, Russia) (λ=635 nm, 0.1 W/cm2 ; 300 s; 30 J/cm2 ).

Results. Administration of KP III without subsequent irradiation did not affect the blood flow velocity during the entire observation period. Laser irradiation of venules without prior administration of KP III led to an increase in blood flow velocity by 39.1 % (p<0.05). After laser irradiation and administration of KPIII, there was a gradual decrease in flow velocity after the photoactivation process.

Conclusions. We studied the effect of photoactivated KP III on microcirculation in the mesentery of the small intestine of rats. Changes in the blood flow velocity in the venules of the mesentery affected by KP III and laser irradiation develop mainly in the post-radiation period and could be associated with endothelial dysfunction.