Laser Doppler Flowmetry Method Research Articles

DEVELOPMENT OF A STRATIFICATION SYSTEM FOR SEVERE ACUTE PANCREATITIS IN THE FIRST DAY OF ITS ONSET

Introduction. Acute pancreatitis stands as one of the prevalent acute inflammatory diseases of the abdominal cavity, marked by a diverse range of clinical presentations and the risk of developing persistent organ failure is too high even in its early stages. At present, the widely adopted framework for assessing acute pancreatitis is the 2012 revised Atlanta classification. However, distinguishing between moderately severe and severe acute pancreatitis within this classification necessitates a minimum of 48 hours to determine the persistence of organ failure. Consequently, the primary challenge in contemporary acute pancreatitis diagnosis and treatment lies in the imperative task of early-stage prognosis and effective stratification of disease severity.
 Objective of this investigation is to determine the availability of optimal parameters of clinical and instrumental examination methods in order to predict the course of acute pancreatitis in the first day of its onset by conducting a statistical analysis of the studies performed.
 Materials and methods. The assessment the state of microcirculation in patients by the method of laser Doppler flowmetry was carried out using the LAKK-02 device according to the specified methodology. Patients were also subjected to general clinical and instrumental examination. In order to study the influence of indicators on the severity of the disease, the paired correlation coefficients of each of them were calculated, after which, for the parameters with the closest connection, a multiple linear correlation-regression model was built and the multiple correlation coefficient with the severity of the disease was calculated.
 Results. The following parameters have the most significant influence on the severity of the disease on the first day: findings of laser Doppler flowmetry C (A/M), systemic inflammatory response syndrome criteria, hematocrit, hydrothorax/peritonitis. In the complex analysis, the multiple correlation coefficient is 0.803, which indicates a significant relationship between the factors included in the model and the degree of severity. The coefficient of determination points out that the degree of severity is 64.5% dependent on the indicators included in the model.
 Conclusions. The obtained results of the study indicate the presence of a complex influence of the criteria of laser Doppler flowmetry C (A/M), criteria of the systemic inflammatory response syndrome, hematocrit, hydrothorax/peritonitis on the severity of the disease in patients with acute pancreatitis within the first day of the disease onset that underscores the potential for early-stage preliminary stratification of acute pancreatitis severity based on these criteria.

Features of blood supply of urethral tissues in women with primary urethral pain syndrome

Introduction. Primary urethral pain syndrome (PUPS) is a part of chronic primary pelvic pain syndrome with predominant localisation of pain in the urethra. The pathogenesis of PUPS has not been adequately studied and there are no unified guidelines for the prevention and treatment of this condition. It is known that one of the main factors in the development of chronic pain is a violation of regional blood flow.Objective. To identify the features of blood supply of urethral tissues, as well as to assess the concomitant changes in the connective tissue in patients with PUPS.Materials & methods. The study included 98 patients: 78 patients with primary urethral pain syndrome (group "PUPS"), without clinical manifestations of inflammation; 20 patients with stones of the upper urinary tract without pyelonephritis, in which the urethra is taken as the norm (group "N"). The hemodynamics of the urethral tissues was studied using transvaginal ultrasound (TVUS) and laser Doppler flowmetry (LDF). Changes in the blood supply to organs often lead to disruption of tissue structure; therefore, in vivo cross-polarisation optical coherence tomography (CP OCT) and ex vivo nonlinear confocal microscopy were included in the study.Results. In the PUPS group, the LDF method revealed a violation of the neurogenic regulation of the tone of the microcirculatory vascular wall of the urethral tissues with a predominance of passive regulatory components. The analysis of the LDF parameters by the method of principal components made it possible to establish the division of data into several clusters, which indicates a different pathogenesis of microcirculation disorders in the tissues of the urethra. The TVUS method in the PUPS group revealed an increase in resistance to blood flow in the blood vessels of the urethra and paraurethral plexus, blood stasis in the veins of the small pelvis in 19% of patients. Violation of the urethral blood flow leads to structural changes in tissues: using nonlinear microscopy, it was found that with PUPS in the urethral connective tissue, collagen fibres are quantitatively larger relative to elastic ones, they are more uniform in thickness, and have a co-directional arrangement. These data correlate with the results of an intravital CP OCT study, during which fibrosis of the subepithelial connective tissue structures was revealed.Conclusion. TVUS and LDF made it possible to reveal the presence of microcirculatory and, as a result, structural changes in urethral tissues in vivo. The inclusion of these methods in the diagnostic algorithm will provide more information about the main links in the pathogenesis of PUPS.

Маркери психоемоційного стресу у жінок київського регіону в період російсько-української війни

War-related stress (WSR) leads to disruption of vital physiological functions, which can accelerate the development of age-related pathology and early mortality. Therefore, the study of the impact of SPV on the functioning of various body systems requires an in-depth analysis. The purpose of the study is to assess the level of psycho-emotional stress, anxiety, and depression and to investigate their influence on indicators of endothelial function, lipid, carbohydrate metabolism, autonomic nervous regulation of the cardiovascular system) in women of the Kyiv region during the Russian-Ukrainian war. 56 women aged 30-78 were examined (average age - 53.45 ± 1.6 years), who had been in the Kyiv region without permission since the beginning of the Russian-Ukrainian war (February 24, 2022). The control group consisted of 79 women aged 29-85 years, (average age - 56.46 ± 1.44 years), who were examined before the start of the Russian-Ukrainian war in 2018-2021. Anthropometric parameters, fasting plasma glucose level and standard oral glucose tolerance test (OGTT), serum lipid concentration, plasma cortisol level were determined. The function of the endothelium of microvessels was studied by the method of laser Doppler flowmetry in a sample with reactive post-occlusion hyperemia, the state of autonomic regulation of the cardiovascular system by the method of heart rhythm variability analysis. Psychoemotional state using the PLC-5 scale, Beck depression scale, Spielberger-Hanin test, the state of cognitive function was studied using the Montreal Cognitive Assessment (MoCA) A statistically significant increase in the level of cortisol, as an important marker of WSR, was revealed, compared to the control group. Excessive psycho-emotional stress of the body during the war is also evidenced by the predominance of the sympathetic link of autonomous nervous regulation in women. The development of endothelial dysfunction and the negative impact of WSR on lipid and carbohydrate metabolism were confirmed, which was combined with a decrease in mental performance indicators, an increase in the levels of personal and situational anxiety, and depression. An increase in the level of cortisol and the activity of the sympathetic link of the autonomic nervous system indicates the presence of chronic psychoemotional stress, which increases the levels of anxiety and depression, reduces the mental performance of women in war conditions and leads to the development of endothelial dysfunction, disorders of lipid and carbohydrate metabolism.

IMPROVEMENT OF DIAGNOSTIC METHOD FOR MICROCIRCULATORY DISORDERS IN ACUTE PANCREATITIS

Introduction. Acute pancreatitis (AP) is one of the most common diseases of the digestive system that requires hospitalization. It ranks the second position after acute appendicitis among acute diseases of the digestive system. The mortality rate from severe AP forms puts this disease in the first position in terms of lethality rates among acute surgical pathology of the abdominal cavity. At the initial stages of the disease, a cascade of immunological reactions occurs that leads to significant changes in rheology and function in the systemic microcirculatory bed in the first hours of the disease. This study aims to identify the optimal point of examination for assessing microcirculatory function in patients with AP and to improve the diagnostic and prognostic capabilities of laser Doppler flowmetry (LDF) in evaluating the AP severity.
 Materials and methods. The assessment of the microcirculatory state of patients by the LDF method was carried out using “LAKK-02” device. During the application of the LDF method, the primary studies were carried out at three points (proximal, central and distal) of the anterior surface of the right forearm. In order to study the effect of indicators on the degree of disease severity, paired correlation coefficients for each of them were calculated for the above-mentioned points.
 Results. All generalized microcirculation indicators (for M - 0.679, for o - 0.653, for Kv - 0.706), as well as respiratory, cardiac and neurogenic indicators in amplitude wavelets at the distal point, have the most significant and considerable impact compared to other points. On the other hand, frequency wavelet data have no significant correlation with the severity of AP in any of the examination points, which characterizes this wavelet as not significant in determining the degree of severity of AP in the 1-3 day examination.
 Conclusion. The findings of this study suggest that by focusing on specific examination points, it is possible to reduce overall exposure and obtain homogeneous data on essential indicators. This approach enables a more comprehensive and higher quality analysis of wavelet indicators, thus improving the diagnosis and prognosis of AP severity.

Functional condition of microcirculation in the zone of intestinal anastomosis during postoperative period upon stimulation of its regeneration (experimental study)

Objectives: to conduct a comparative assessment of the functional condition of microcirculation of the digestive anastomosis zone in the early and delayed postoperative period upon local usage of autogenic growth factors (PRP). The experiment was performed on 30 mature laboratory rabbits. All animals underwent the imposition of two digestive "end-to-end" intestinal anastomosis: the control one at a distance of 15 cm from the ileocecal angle and the experimental one retreating 30 cm from the imposed anastomosis. The experimental anastomosis differed from the control one by using a method of local stimulation of its regeneration via injecting of platelet-riched-plasm (PRP). A comparative assessment of the functional state of the microcirculation of the intestinal anastomosis zone was carried out on the 3rd, 7th, 14th days in the postoperative period using the method of laser doppler flowmetry (LDF). The obtained data determined the ability of the PRP method to improve the conditions of the regenerative process in the intestinal anastomosis zone by increasing the rate of basal blood flow and tissue perfusion, the rates of which have maximum values in the early postoperative period (3 day).

Kinetics of mucosal blood flow in 3D modeling of the gingival contour around dental implants after bone reconstruction of the alveolar ridge in the lateral part of the jaws

To study the kinetics of mucosal blood flow in 3D modeling of the gingival contour around dental implants after bone reconstruction of the alveolar ridge in the posterior jaw. The work was performed at the clinical base of the Department of Surgical Dentistry and Maxillofacial Surgery of the Institute of Dentistry of the Privolzhsky Research Medical University, Nizhny Novgorod, Russia with the participation of 87 patients who were divided into two groups depending on the chosen method of treatment and a control group. The method of laser Doppler flowmetry was carried out using a multifunctional laser diagnostic complex LAKK-02. The terms of observation were 7, 14, 28, 42 days. On the 7th postoperative day, the decrease in microcirculation index (MI) in the groups reflected moderately pronounced hemodynamic disorders with a predominance of a decrease in MI in the center (by 35.8%). The predominance of the stagnant-ischemic type of microcirculation disorders and low intensity of neoangiogenesis was established, especially in the central zone in group 1, and in group 2 signs of neoangiogenesis were noted by the 7th day. By the 14th day, there was a decrease in venous congestion and signs of arterial inflow. In the 2nd group there was a subsidence of inflammatory phenomena and an increase in the energy of the oscillatory process in the vessels. Gradually, by the 42nd day, the indicators in groups 1 and 2 approached in value to the control group and did not differ significantly. A previously unknown mechanism of interaction between two heterogeneous grafts (xenograft and thin free gingival graft) was revealed, which determined neoangiogenesis by the traditional method (from the center to the periphery), and by the proposed method (from the periphery to the center). Understanding the wound process is necessary for the purpose of further correction of the surgical technique for the best restoration of the vascular network and an increase in the success rate of operations.

Complex assessment of parameters of central hemodynamics and microcirculation in children of 6-7 years old

The paper presents the results of a comprehensive assessment of central hemodynamic and microcirculation indices in the skin of upper and lower limbs in 6–7-year-old children. 14 girls and 7 boys were examined using laser Doppler flowmetry methods (the LASMA-PF device, allowing simultaneous recording by four sensors) and the analysis of heart rate variability ("Varicard"). The parameters characterizing microcirculation in the limbs were determined and the signs of the appearing functional asymmetry of the upper limbs, as well as the differences in the mechanisms of modulation of cutaneous blood flow in boys and girls were revealed. The estimation of heart rate variability reveals the signs of girls' inclination to sympathotony and boys' inclination to vagotony at the given age. It was marked that central regulation mechanisms have the greater contribution to cardiac rhythm formation in girls. The data obtained testify to the fact that age-related changes at different levels of the cardiovascular system and regulation mechanisms occur somewhat earlier in girls than in boys.

Features of laser Doppler flowmetry in patients with bacterial and viral (covid-19) community-acquired pneumonia

Introduction. As a result of the coronavirus infection (COVID-19) pandemic, almost 74.9 thousand people died of pneumonia in Russia in 2021. Community-acquired pneumonia (CAP) is accompanied by a systemic re­sponse of the body to inflammation in the lung tissue and disorder of microhemocirculation. The method of laser Doppler flowmetry (LDF) allows assessing the general parameters of the microcirculatory bed and determining the state of various factors regulating the nutritive flow.Aim. To conduct a comparative analysis of LDF indices in patients with COVID-19- associated and bacterial CAP.Materials and methods. 140 patients were examined, 100 of them with non-severe CAP (main group), and 40 patients with extrapulmonary pathology (comparison group). The main group included 44 people with bacterial CAP and 56 people with COVID-19-associated CAP. Bacteriological studies of sputum were performed; detection of SARS-CoV-2 RNA in swabs from the oropharynx and nasopharynx by PCR, LDF to assess the state of pe­ripheral blood flow was carried out.Results. In patients with COVID-19-associated CAP, compared with patients with bacterial CAP, a decrease in the microcirculation index by 1.26 times (p<0.0005), an increase in the coefficient of variation by 1.11 times (p<0.0005) was found.Conclusion. In patients with COVID-19-associated CAP, compared with patients with bacterial CAP, more significant pathological changes in Dopplerograms were detected, which may indicate more pronounced disorders in the microcirculatory bed in COVID-19-associated CAP caused by exposure to the SARS-COV- 2 virus. Perhaps the established fact can lead to adverse outcomes of the course of the disease.

THE MORPHOLOGICAL AND FUNCTIONAL STATE OF THE VASCULAR COMPONENT OF HEMATOPOIESIS ORGANS IN DIFFERENT TIMES OF SIMULATED HYPOXIA IN THE EXPERIMENT

Under conditions of hypoxia, a change in the morphological and functional state of the components of the microvasculature bed will be accompanied by a change in the adequacy and usefulness of the immune response and hematopoiesis. The purpose of the study was to determine the morphofunctional state of the vascular component of the red bone marrow and spleen at various times of simulated hypoxia and to identify the degree of influence of CD68-positive cells on this state. Chronic hypoxia was modeled on 246 outbred male rats using special chambers containing natural gas from the Astrakhan gas field (Russia) at a concentration not exceeding the maximum allowable. The experiment was continued for 120 days, inhalation was carried out five days a week for four hours a day, the removal of animals from the experiment was carried out every 30 days. The functional activity of the vascular component of the red bone marrow was determined using the method of laser Doppler flowmetry. The degree of expression of inducible (iNOS) and endothelial (eNOS) NO synthases and the distribution of CD68-positive cells in the spleen structures were determined by immunohistochemical method. The study showed that as the duration of chronic simulated hypoxia increases, there is a decrease in the microcirculation index, an increase in myogenic tone and shunting index, which, taken together, indicates a deterioration of organ perfusion and confirms the formation of a hypoxic state. An analysis of the functional activity, carried out using an immunohistochemical study of the expression of iNOS and eNOS in the structures of the spleen, showed that as the duration of the experiment increased, the level of endothelial synthase decreased and the level of inducible synthase increased. Perhaps this is due to the influence of biologically active substances secreted by macrophages activated during hypoxia. This is supported by an increase in the presence of CD68-positive cells in the red pulp and along the connective tissue trabeculae as the experimental exposure increases.

The place of laser fluorescence spectroscopy, doppler flowmetry and ultrasound in the diagnosis and assessment of treatment efficacy for plaque scleroderma

According to modern ideas, a reasonable choice of an effective method of treating plaque scleroderma is based on the diagnosis of the pathological process prevailing in the tissues (inflammation-sclerosis). Therefore, an urgent problem of a personalized approach to dermatosis therapy is the possibility of an objective assessment of the prevailing process using non-invasive diagnostic methods. The article presents a clinical case of widespread plaque scleroderma in a 66-year-old patient, demonstrating the possibility of using laser fluorescence spectroscopy and laser Doppler flowmetry to determine the degree of activity of the focus and determine the leading pathological process.
 We selected three pathological skin foci localized in the abdomen and characterizing three clinical stages of the disease (inflammation, induration, sclerosis). The analysis of fluorescence and laser Doppler flowmetry data showed that in areas clinically defined as inflammation, there is an increase in the average values of the indices of tissue content of porphyrins, lipofuscin and microcirculation index compared with intact skin, while the intensity of collagen fluorescence does not differ significantly. In the induration zone, along with an increase in the fluorescence indices of lipofuscin and porphyrins, there is an increase in the average values of collagen fluorescence indices at effective registration waves. The data obtained by us indicate an active inflammatory process in these foci and the process of fibrosis in the induration zone. In the sclerosis zone, there is an increase in the average values of collagen fluorescence indices compared with intact skin, and the fluorescence of optical markers of inflammation (lipofuscin and porphyrins) do not differ significantly in comparison with the control intact skin. When analyzing the fluorescence spectra and laser Doppler flowmetry data after treatment, we found that in the zones of induration and inflammation, the average values of the fluorescence indices of porphyrins, lipofuscin, collagen and microcirculation index are reduced relative to the initial values (before treatment), but remain higher in comparison with intact skin. The data obtained may indicate that active inflammation in these foci persists at the time of the study. In the study of the focus of sclerosis, the obtained autofluorescence and microcirculation data in dynamics do not differ significantly from the initial values. The data for laser Doppler flowmetry and laser fluorescence spectroscopy are consistent with ultrasound examination of the skin.
 In our study, the potential possibility of using laser fluorescence spectroscopy and laser Doppler flowmetry methods to establish the degree of activity of the focus, determine the leading pathological process, as well as to evaluate the effectiveness of therapy was demonstrated for the first time.

МИКРОЦИРКУЛЯТОРНЫЕ НАРУШЕНИЯ СЛИЗИСТОЙ ОБОЛОЧКИ АЛЬВЕОЛЯРНЫХ ОТРОСТКОВ У ПАЦИЕНТОВ С МЕДИКАМЕНТОЗНОАССОЦИИРОВАННЫМ ОСТЕОНЕКРОЗОМ ЧЕЛЮСТИ

The research is relevant due to the widespread use of osteomodifying agents among patients with bone metastases with malignant neoplasms of various localization. The healing process is sluggish due to the toxic effect of these medications, including their influence on soft tissues; it often occurs that relapse sets in after surgical treatment. The research aims to study possible variants and degree of mucosa microcirculation disorders of the alveolar processes among patients with drug-associated osteonecrosis of the jaw. Materials and methods of the research. Microcirculation was examined with the method of Laser Doppler flowmetry (LDF) with the LAKK-OP analyzer (modification 1) (SPE “LAZMA” Ltd, Moscow). The patients diagnosed with drug-associated osteonecrosis of the jaw were examined for microcirculation by Laser Doppler flowmetry method in the lesion and at the side with no visible clinical manifestations. The exclusion criterion was the patient’s general medical condition with the score no less than three on the EGOC scaling. The comparison group included practically healthy volunteers. The exclusion criteria were complete secondary adentia, heart defects, hypertension, vascular pathology, diabetes mellitus, cancer, bronchial asthma, chronic obstructive pulmonary disease, maxillofacial inflammatory diseases, HIV infection. 
 Results. The perfusion index among the patients with drug-associated osteonecrosis of the jaw was lower by 0.65 pf. units (17,53 ± 4,04 pf. units) in the lesion and by 2,14 pf. units (16,14 ± 3,23 pf. units) at the side with no visible clinical manifestation compared to the healthy group (18,18 ± 6,24 pf. units). The average amplitude of myogenic oscillations in the main group (3,24 ± 2,08 pf. units) was higher than the oscillation indices of different origin; on the contrary, in the comparison group, as well as in the healthy part of the main group, the amplitude of neurogenic oscillations prevailed (1,64 ± 0,91 pf. units and 3,41 ± 1,53 pf. units). Conclusion. The research reveals impaired microcirculation symptoms of the ischemic-stagnant type, both in the lesion and at the side with no visible clinical manifestations, which indicates a system failure of the mucous membrane of alveolar processes among these patients.

Age dynamics of indicators of the microcirculation system in students according to laser dopler flowmetry

The article is devoted to the problem of studying blood microcirculation in healthy individuals at different stages of ontogenesis.
 The aim of the study was to investigate the peculiarities of the skin blood flow in students aged 17-21.
 Materials and ways of the research. In order to study the functional state of blood microcirculation the method of laser Doppler flowmetry (LDF) was used.
 Results. Determination of the age dynamics of the tissue blood flow in subjects aged 17-21 years showed that the parameter of microcirculation in the subjects increased from minimal values at 17 years to maximal values at 21 years. In the female subjects, the value of the microcirculation parameter was higher at 17 years than in the male subjects, while the maximum perfusion value for girls was at 19 years and at 20 years in the male subjects. Assessment of the regulatory devices showed that the amplitude value of low-frequency oscillations in females fell at the age of 19 years and in males at 20 years. The maximal amplitude index of vasomotor oscillations was registered at the age of 19 years both for boys and girls. The amplitude of vasomotor oscillations in the high-frequency range varied in both girls and boys. Three types of LDF-grams were identified among the young adolescents: aperiodic LDF-grams, which correspond to normoemic type of microcirculation, monotonous low amplitude LDF-grams, which correspond to hypooemic type of microcirculation, sinusoidal LDF-grams, which correspond to hyperemic type of microcirculation.
 Conclusions. As many studies have shown, the heterochronicity of values of blood microcirculation indices is preserved in male and female subjects: in one age section the indices are higher in females, in the other one – in adolescents. This fact reflects the general biological regularity of different maturation of male and female organisms

PHARMACOTHERAPY POSSIBILITIES OF CARDIOVASCULAR AUTONOMOUS NEUROPATHY IN CHILDREN WITH TYPE 1 DIABETES MELLITUS AT THE PRECLINICAL STAGE

The aim of the article is to evaluate the effectiveness of the thioctic acid preparation in the complex therapy of type 1 diabetes mellitus (T1DM) in children with cardiovascular autonomic neuropathy at the preclinical stage.Materials and methods. A design is a prospective randomized study. A clinical and instrumental examination of 64 children with preclinical stage signs of diabetic cardiovascular autonomic neuropathy (DCAN) was carried out. The cohort was divided into 2 groups: in the main and control groups, glycemic control was normalized by adjusting a dose of insulin therapy; in the main group, the children additionally received thioctic acid at the dose of 600 mg/day for 3 months. To control the effectiveness of the therapy, the technique of laser Doppler flowmetry was used.Results. After the pharmacological intervention, there was an improvement in the disease course, normalization of carbohydrate and lipid metabolism, increased vasomotor mechanisms of the regulation of the tissue blood flow due to an increase in endothelial and neurogenic kinds of activity in combination with a decrease in the intravascular tone and an increase in the effective perfusion in tissues. An increase in the heart rate variability was detected, positive dynamics of cardiovascular tests indicators according to D. Ewing, temporal (pNN50%, SDNN) and spectral indicators (VLF) were diagnosed. Achievement and maintenance of the target values of glycemic control indicators, as well as the absence of glycemic variability, turned out to be clinically significant for reducing the manifestations of neuropathy. The non-invasive technique of laser Doppler flowmetry is informative for the early diagnosis of DCAN in T1DM children.Conclusion. The carried out studies have demonstrated the effectiveness of the lipoic acid use at the dose of 600 mg/day for 3 months in the children with DCAN signs at the preclinical stage. The method of laser Doppler flowmetry for determining indications and monitoring the effectiveness of therapy makes it possible to implement a personalized approach to prescribing preventive treatment in T1DM children.

To the possibility of detecting the "coronary theft" syndrome in small laboratory animals

The purpose of the study. There are investigation of the possibility of using the laser Doppler flowmetry method to assess blood microcirculation and analyze the mechanisms of its regulation in conditionally intact and ischemic myocardium in small laboratory animals (rats) to identify the "coronary theft" syndrome. Materials and methods. The experiments were carried out on white mongrel anesthetized (urethane 1300 mg/kg /b) male rats weighing 200-250 g. 28 days after the reproduction of an experimental myocardial infarction in an open chest and artificial lung ventilation, the microcirculation level was assessed in conditionally intact and ischemic areas of the myocardium by laser Doppler flowmetry. Using spectral wavelet analysis, the amplitudes of microcirculation oscillations normalized to the total perfusion associated with various regulation mechanisms were determined. Results. It was found that the microcirculation level is significantly lower in the ischemic zone of the myocardium compared with the conditionally intact one (17.3±2.8 and 30.3±1.3 per. units, respectively, p = 0.006, n = 8). Spectral wavelet analysis showed that in the ischemic injury zone, in comparison with the conditionally intact myocardium, the amplitudes of microcirculation oscillations normalized to the general level of microcirculation increase for all regulatory mechanisms. Conclusion. The laser Doppler flowmetry method can be used to assess the intensity of microcirculation in conditionally intact and ischemic myocardium. Using this method makes it possible to identify the "coronary theft" syndrome in experiments on small experimental animals.

INVESTIGATION OF MICROCIRCULATION PECULIARITIES IN THE ZONE OF DIGESTIVE ANASTOMOSIS DURING EARLY AND DELAYED POSTOPERATIVE PERIOD AS A PREDICTOR OF ITS INSUFFICIENCY

The aim of the research is to evaluate the condition of blood flow in the area of digestive anastomosis in the early and delayed postoperative period in an experiment. The experiment included 30 sexually mature laboratory rabbits-males of the breed Soviet Chinchilla. The animals were done laparotomy, enterotomy, followed by the imposition of a digestive single-row nodular anastomosis "edge to edge", then the evaluation of local blood flow condition in the zone of digestive anastomosis was performed in the early (3 days) and delayed (7, 14 days) postoperative period using the method of Laser Doppler Flowmetry (LDF). The data received demonstrated a decrease of local blood flow in the early postoperative period in the area of digestive anastomosis, that forms the most vulnerable period for the development of its insufficiency. In the delayed postoperative period, there is an improvement in the indicators of local blood flow in the anastomosis zone, with an approximation of their values to the condition of the intact intestinal tract.

Effect of Hypoxia on the Stability of Microcirculation Parameters in the Temporal Head Regions of Humans

—A new computational and experimental method for assessing the stability of oscillatory processes occurring in the microcirculation (MCR) system is proposed. The technique is based on the analysis of the stability of a differential equations system describing fluctuations in the MCR parameters of blood in symmetrical temporal head regions of humans. Using this technique, we have investigated the change in the stability of MCR parameters of the symmetrical temporal head regions under hypoxic conditions. The study has involved 10 healthy male volunteers (18–19 years). The state of short-term hypoxia has been induced using a normobaric ReOxy Cardio device (S.A. Aimediq, Luxembourg) certified in the Russian Federation for obtaining hypoxic and hyperoxic gas mixtures based on biofeedback with a built-in pulse oximetric sensor (Masimo Rad-5, United States). Synchronous measurements of MCR parameters of symmetrical temporal head regions at the basal state and immediately after short-term hypoxic exposure have been carried out by the method of laser Doppler flowmetry (LDF) using a two-channel LAKK–02 device (LAZMA Research and Development enterprise, Russia). It has been shown that short-term hypoxic effects change the numerical values of the stability parameters in all subjects within the boundaries of stability levels. However, the response to hypoxic exposure has been very individual in different subjects. The proposed method allows for personalized assessments of the fitness level and resistance to hypoxic influences in different subject groups.

Changes in micro- and central hemodynamic parameters in rats under the action of acetylsalicylic acid and its coordination compounds with metals

Introduction. The cutaneous blood circulation is a representative model both for studying the mechanisms of vascular diseases and for assessing the current state of the central hemodynamics in preclinical researches of various chemical compounds. Aim. The changes in the parameters of cutaneous microcirculation and central hemodynamics (heart rate and blood pressure) were studied in the animals under the action of acetylsalicylic acid and its coordination compounds with cations of cobalt, zinc, nickel and manganese at a dose of 20 mg/kg. Materials and methods. The research was conducted using the laser Doppler flowmetry method on the Lazma-MC device (manufactured by RPE Lazma, Russia) and the NIBP200A system (Biopac Systems, Inc., USA). Results. The study shows that animals develop bradycardia, and microcirculation and central hemodynamics change in two ways after the introduction of acetylsalicylic acid and the tested metal salicylates. These ways are hypotension-related hyperemia (acetylsalicylic acid and cobalt salicylate) and ischemia (zinc, nickel and manganese salicylates) associated with hypertension. Conclusion. The obtained data confirm the cardiotropic activity of new coordination compounds. The data also prove that the generation of the acetylsalicylic acid derivatives allows enhancing it physiological effects, as well as obtaining completely new molecules. The molecules are different from the precursor one and are necessary for the production of effective drugs.

Correlation and spectral analysis of microcirculatory changes in symmetric areas of human head in short-term hypoxic exposure

Purpose. To study the effect of short-term hypoxic exposure on correlation between microcirculatory parameters (MCR) of symmetric areas of the human head. Materials and methods. MCR parameters of 10 healthy male volunteer were measured by laser Doppler flowmetry method. Short-term hypoxic exposure was produced according to the hypoxic test method using the ReOxy Cardio unit (S. A. Aimediq). We assessed the perfusion metrics left and right areas of interest, neurogenic, myogenic, respiratory and cardiac contributors to vascular tone and correlations between baseline parameters and after hypoxic exposure. Results. We revealed the specificity of regional circulation system rearranging induced by hypoxic load. The specificity is caused by functional asymmetry of correlations between different vascular tone contributors in symmetrical head areas. Strong correlation declining under the hypoxic loads between baseline perfusion on left/right was found. The perfusion changes of symmetrical temporal areas under the hypoxic loads correlate negatively with the baseline perfusion of both the same and the opposite side. Conclusion. Short-term hypoxic load rearranges the balance of different vascular tone contributors regulatory role in MCR of symmetric head areas to maintain the sustainable activity of the whole MRC.

Investigation of changes in the skin blood microcirculation when performing the hatha yoga breathing technique

Introduction. Yoga breathing exercises improve the ability to significantly reduce the respiratory rate. A decrease of the minute respiration volume results in compensatory reactions of the microcirculatory bed caused by changes in the gas composition. The reaction of the regulatory mechanisms of the microvascular bed can be evaluated by the optical non-invasive laser Doppler flowmetry method. The aim of the study was to assess the tissue microcirculation parameter changes in people performing yoga breathing exercises. Materials and methods. 25 volunteers performed yoga breathing exercises at a frequency of 3 times per minute, 2 times per minute, 1.5 times per minute, 1 time per minute for 5 minutes, and free breathing for 6 minutes before and after breathing exercises. Parameters aimed to defin the reaction of skin microcirculation in different body areas were simultaneously recorded in six sites by laser Doppler flowmetry using a distributed system of wearable analyzers. The parameters of tissue microcirculation recorded by the method of laser Doppler flowmetry were: the index of microcirculation (Im), nutritive blood flow (Imn), the amplitude of myogenic (Am), neurogenic (An), endothelial (Ae), respiratory (Ar) and cardiac (Ac) regulation circuits. Results. Yoga breathing exercises led to increase of microcirculation index at all breathing frequencies. Breathing at a frequency of 1.5 and 1/minute leads to a significant increase in nutritional blood flow. Low-frequency breathing exercises lead to an increase in blood pressure at the lowest breathing rates – 1.5/minute and 1/minute. The most significant changes were achieved at the lowest respiration rates (1 and 1.5/minute), that could be associated with hypoxic-hypercapnic mechanisms. Conclusion. The absence of significant changes in microcirculation parameters after low-frequency respiration during measurements in the supraorbital arteries in both groups characterizes the work of homeostatic mechanisms for maintaining brain perfusion in stressful situations for the body (low-frequency types of respiration, hypercapnia and hypoxia). When measured in the extremities, a change in the effect of the circulatory system regulatory mechanisms was observed; along with an increase in skin perfusion and the nutritional component, it can characterize the compensatory reaction of the microcirculation to respiration change.

Кровоснабжение суставов нижних конечностей у детей с болезнью Легг — Кальве — Пертеса до и после лечения с помощью эпидуральной анальгезии

Using the method of laser Doppler flowmetry (LDF), 10 healthy boys aged 7 to 9 years and 10 boys of the same age with unilateral hip joint lesion at stage III–IV of Legg — Calve — Perthes disease were examined. In all the examined patients, compared with the healthy subjects, a significant decrease in microcirculation in the hip joint, knee joint and joint of the first toe was found. Prolonged epidural analgesia led to a significant increase in microcirculation in all the examined joints, which indicates the high effectiveness of this method of treating the disease. The LDF method can also be useful for early diagnosis of Legg-Calve-Perthes disease in children.