Prospects for the use of laser Doppler flowmetry to assess cutaneous blood microcirculation in diabetes mellitus

The аrticle considers the scientific and clinical aspects of laser Doppler flowmetry (LDF) in the diagnosis of the state of the microcirculatory bed in diabetes mellitus. LDF is a non-invasive quantitative method of microcirculation assessment; its capabilities include the analysis of microcirculatory rhythms and functional testing with different types of provocation tests, which provides a study of the state of regulatory mechanisms of microcirculation. The difficulties with studying the microcirculation are caused by the very small size of microvessels. The prevention and treatment of various microcirculatory disorders is one of the most important problems in medical practice. The findings of some studies suggest that microcirculatory disorders are not only a pathogenetic link in the development of complications, but are also observed in patients with early disorders of carbohydrate metabolism and may precede the manifestation of diabetes mellitus. The use of LDF in scientific researches will make it possible to reveal changes in microcirculatory bed functioning that are characteristic of diabetes mellitus. The possibility of non-invasive quantitative assessment of the state of microcirculatory blood flow in real time and the relative ease of use explains the high popularity of LDF in scientific researches and makes this method promising for use in clinical practice. This method can be of important diagnostic value for the study of the state of different levels of regulation of the microcirculatory tract and dynamic monitoring of the effectiveness of the prescribed treatment. Combined use of LDF to identify the risk of developing diabetic foot syndrome will allow to personify the treatment of diabetes. Among the most promising points of application should be noted the study of microcirculation in the early diagnosis of diabetes and its complications, clarifying the risk of complications, monitoring the effectiveness of treatment. The development of optimal evaluation methods of microcirculation is a prospect for further research.

Features of the extrapancreatic action of glibenclamide in cerebral ischemia in the highlands

The features of remodeling of the components of the vascular plexus and the microcirculatory bed of the brain in cerebral ischemia in the highlands are studied, the features of the action of glibenclamide on these structures are presented. It is shown that the sulfonylurea receptor 1 (SUR 1) in the highlands becomes more sensitive to glibenclamide than in the low mountains. Key words: brain, ischemia, glibenclamide, highlands.

OCT-A PICTURE OF THE EYEFOOL IN CHRONIC RENAL FAILURE

Renal retinopathy is a severe late microvascular complication of CRF and one of the causes of blindness in the world among people of working age. OCT-A makes it possible to detect microvascular changes in the retina even in the absence of clinical manifestations of renal retinopathy on the fundus. Markers of changes in the microcirculatory bed of the retina in renal retinopathy arequalitative and quantitative changes in the foveal avascular zone and a decrease in the density of the capillary network, which increase with the progression of the disease.Keywords:Renal retinopathy, CRF, OCT, angiography, retinal changes

THE DYNAMICS OF LUNG HISTOPATHOLOGY IN ACUTE BACLOFEN POISONING

Baclofen (sold under the name Baclosan©, Lioresal©) is a muscle relaxant. This drug is chemically different from other muscle relaxants. Due to its pronounced psychotropic effect the drug is often a subject of abuse especially among young people. The article deals with the dynamics of lung histopathology in acute baclofen poisoning. Experimental studies were performed on 15 Wistar rats. The animals were divided into 3 groups (the controls and two experimental groups). The controls included 5 intact rats. Each experimental group included 5 animals. Both groups were treated with baclofen at a dosage of 85 mg/kg. The duration of the experiment was 3 and 24 hours, respectively. We revealed a complex of pathological changes in the lungs of the rats. There were circulatory disorders in all the elements of the microcirculatory bed, areas of emphysema, atelectasis and dystelectasis, WBC infiltration of intralveolar septa and their thickening due to edema. The changes were even more severe 24 hours after the drug administration. These results along with the results of chemical analysis will be useful in establishing the fact of baclofen intoxication and the exact moment of the intoxication.

Microcirculatory bed in reperfused flaps: modern possibilities for the correction of hemodynamic disorders (part III)

The paper presents an analysis of the literature data concerning the autoregulation of tissue blood flow in free axial flaps. Autoregulation of microcirculation is an extremely important physiological phenomenon that ensures the stability of peripheral blood circulation and adequate metabolism in organs and tissues, regardless of fluctuations in systolic blood pressure in the range of 80-160 mm Hg. The types of sludge and their origin are described. Technologies of elimination of erythrocyte aggregates (sludge) by using dextrans of different molecular weights and pentoxifylline are discussed. Controlling the duration of primary ischemia, maintaining adequate perfusion pressure in the replants of the limbs and in free flaps, as well as reducing the peripheral vascular resistance in them, will make it possible to level the disturbances in the autoregulation of microcirculation in the reperfused tissues, ensuring the stability of capillary pressure.

The Cervical Fold Suspension Model of Acute Stress in Rats and Its Impact on the Spleen

Notwithstanding the long history of research, versatile studies of stress effect on living organisms are relevant to date. The stress response that arose in the process of evolution as a component of the adaptation process, in case of its unfavorable course, can trigger pathogenetic mechanisms of numerous pathologies. Investigation of the effect of stress reactions on living organisms requires the use of laboratory animals in the experimental studies, to which there is currently no alternative. In our opinion, special attention should be paid to those experimental models of stress that are easy-to-use, cost effective and are in concordance with current principles of bioethics. The purpose of the study was to study the impact of 6-hour-long cervical fold suspension experimental model of acute immobilization stress on the albino rat spleen. Material and methods. Based on the international bioethical principles, 10 male albino rats were involved in the study. The intact animals were assigned into control Group I (n=5); experimental Group II (n=5) involved animals, exposed to 6-hour-long cervical fold suspension model of acute immobilization stress. After euthanasia, macro- and microscopic examination of the spleen was made. Microspecimens were stained with hematoxylin and eosin. Results and discussion. The macroscopic analysis of the spleen revealed no visual differences in the rats of the experimental group compared to control ones. Histological study of the spleen specimens of the rat of Group II has shown sparse perivascular swellings of the central arteries, thickening of the periarterial zone, narrowing of the diameter of the germinal center due to the cell redistribution that was detected in the white pulp in the medium and large lymphoid nodules under the effect of the acute immobilization stress induced by the atraumatic cervical fold suspension for 6 hours. The above changes led to a relatively slight increase in the volume of the white pulp of the spleen by 4.23 ± 1.52%. A clear boundary between the white and red pulp was noted. In addition, disturbances in the microcirculation in the vessels of the hemomicrocirculatory bed, manifested by edema of the splenic stroma, plethora of vessels and a decrease in the number of erythrocytes in these areas in the subcapsular departments were noted. In the deeper layers of the spleen, foci of sparse perivascular diapedetic hemorrhages were found with the phenomena of blood stasis in the microcirculatory bed, leukostasis and sludge phenomenon. The described changes led to blood flow slowing in the microcirculatory bed with subsequent adhesion of erythrocytes and the formation of blood clots in the vessels of larger diameter. Thus, histologically, acute stress induced by cervical fold suspension causes minor morphological changes in the spleen of rats of the experimental group, the moderate severity of which indicates the relative resistance of splenic structures to the action of 6-hour-long immobilization. Conclusion. The findings of the study showed the relative resistance of the rat spleen to 6-hour-long stress caused by cervical fold suspension, with minor morphological changes in the white pulp and impaired hemomicrocirculation

Tonsillogenic Changes in the Choroid and Retina. Experiment

Purpose. Experimental study of tonsillogenic changes in the choroid and retina in an. Material and methods. Clinical and functional studies of the eyes of animals were carried out 3 months after modeling of chronic tonsillitis. Fundus images were photographed using RETCAM II (USA) wide-field digital pediatric retinal camera. Optical coherence tomography (OCT) was performed on 3D OCT-1000 MARK II optical coherence tomograph (Topcon, Japan). The functional state of the microhemocirculatory bed in the equatorial part of the eye was determined transscleral with laser Doppler flowmetry using LAKK-02 analyzer. Results. 3 months after the modeling of experimental chronic tonsillitis, dystrophic changes in the layer of nerve fibers, RPE dysfunction, and a reduced thickness of the own choroid persist. There is a deterioration in the functional state of the microcirculatory bed in the equatorial part of the eye. Conclusion. The use of optical coherence tomography, along with laser Doppler flowmetry, seems to be promising in assessing chorioretinal changes after modeling chronic tonsillitis. In the long term, after modeling of chronic tonsillitis, dystrophic changes in the layer of nerve fibers, hyperplasia of RPE cells, and a decrease in the thickness of its own choroid persist. There is a deterioration in the functional state of the microcirculatory bed in the equatorial part of the eye. Key words: chronic tonsillitis, laser Doppler flowmetry, retinal pigment epithelium, nerve fiber layer, choroid.

Optical coherence tomography-angiography as a non-invasive method of pathology diagnosis of the microcirculatory bed of the optic nerve and macula

The review discusses the development of optical coherence tomography with the function of angiography, focusing on its advantages, features, and prospects for the diagnosis of fundus pathologies.

THE IMPACT OF SMOKING ON THE MORPHOFUNCTIONAL STATE OF PERIODONTAL TISSUES OF YOUNG ORGANISM

Background. The interrelation of disorders in periodontal tissues with metabolic changes caused, in particular, by a violation of microcirculation, observed namely in smoking but the fact that the effect of smoking on the condition of periodontal tissues at a young age has been studied less than other risk factors deserves special attention. The aim of our study was to experimentally assess the effect of smoking on the morphofunctional state of periodontal tissues in young animals. Materials and methods. Simulation of smoking has been performed with ten-week-old WAG rats using the Boyarchuck chamber. Morphometric studies were performed in the gingival zone which was chosen for morphological interpretation of volumes of specific vascular density in microcirculatory bed, specific density of connective tissue in lamina propria and specific area of tissue with ischemia. The obtained digital data were processed by the methods of variation statistics. Results. Simulation of smoking for four weeks in experimental animals leads to pathological changes in the morphofunctional state of the periodontium with reducing vascular density from 19.44±1.97% to 11.03±1.38 %, increasing area of connective tissue from 18.33±2.71% to 26.49±1.24%, spreading area of tissue with ischemia from 1.14±0.70% to 6.35±1.67%. Conclusions. Morphofunctional changes in the periodontium with damage to the structure of the epithelial membrane and changes in its permeability, microcirculatory disorders, sclerotic changes are a manifestation of the initial inflammatory and dystrophic processes that can lead to persistent chronic pathology.

Morphological rearrangement of the metabolic link of the microcirculatory bed of guinea pigs lungs after sensitization with ovalbumin

The reaction of the lung microvessels is an urgent issue of morphology and medicine in general, as well as one of the insufficiently investigated points in the study of morphological changes in chronic allergic diseases of the respiratory system. The aim is to study the morphological changes in the vessels of the metabolic link of the microcirculation in the lungs of guinea pigs sensitized with ovalbumin. Materials and methods. We have studied the lungs of 48 guinea pigs, using histological and morphometric methods, under conditions of experimental ovalbumin-induced allergic inflammation, simulated by three-time subcutaneous sensitization and subsequent 8-day intranasal inhalation of ovalbumin. To estimate the structural and functional state of capillaries, the inner diameter of the vessels was determined. Results. A general regularity in the reactivity of the hemomicrocirculatory bed of guinea pig lungs in experimental ovalbumin-induced allergic inflammation was established, which consists in a significant structural and functional restructuring of the exchange vessels of the microcirculatory bed. Dysfunction of the capillaries endothelium is manifested by a change of vasodilatation to vasospasm, as evidenced by morphometric changes in the diameter of the capillaries lumen in the experimental groups, and an increase in the permeability of the capillaries wall, which is confirmed by edema and disorganization of the connective tissue component. Conclusions. Allergic inflammation leads to structural and functional reorganization of the metabolic link of the hemomicrocirculatory bed of guinea pig lungs, which has a multidirectional staging character depending on the duration of the experiment and is a manifestation of a violation of the compensatory-adaptive processes of hemomicrocirculation. The most pronounced changes in the form of a decrease in the diameter of the lumen of the blood capillaries of the lungs of guinea pigs by 23 % compared to the control are observed during the late period of the development of the allergic inflammatory process.