Vol 153, No 1 (2018)

Objective - to study structural and histochemical changes in neurons of the rat frontal cortex after ligation of common bile duct. Materials and methods. Frontal cerebral cortex was examined in 72 male outbred albino rats of 200±25 g body mass. Histological and histochemical methods were used to study the microstructural changes of the pyramidal neurons in all the layers of frontal cortex 2, 5, 10, 20, 45 and 90 days after common bile duct ligation and cholestasis development (experimental group) or after a sham operation (control group). Results. It was found that common bile duct ligation in rats followed by cholestasis resulted in a profound histological and histochemical alterations in the neurons of frontal cerebral cortex that included the changes of cell size and form, emergence of the hyperchromic wrinkled neurons and ghost neurons. Disturbance of energy and plastic metabolism of neurons lead to the death of the experimental animals. Consequences of a cholestasis appeared in rat brain at days 2-5 and reached their maximum at days 10-20. At protracted time periods after the operation (days 45-90) in the group of surviving animals these disturbances gradually regressed though consequences of a cholestasis were manifested by the foci of neuronal loss in all the layers of frontal cortex. Conclusions. It is assumed that survival of rats after ligation of the common bile duct is due to the formation of the biliary tract bypasses resulting in the disappearance of cholestasis, and to high adaptive capabilities of neurons.

Objective - to study the morphometric parameters and serine racemase expression in the hippocampus of rats exposed to repeated gravitational overloads in caudo-cranial direction (-9 Gz). Material and methods. 12 months-old rats were exposed to a force of 9G for 5 min twice daily with an interval of 12 h for 28 days - group 2 (exposure to gravitation, n=10). Rats not affected by hypergravitation formed group 1 (control, n=10). Morphometric methods were used to calculate an average size of the cell nuclei and perikarya of pyramidal neurons, the proportion of neurons with the signs of damage, the relative areas of pyramidal neuron perikarya and neuropil. Immunohistochemically the level of serine racemase expression was studied in all the hippocampal areas. Results. The signs of cerebral microcirculatory disorders were detected such as spongiosis, capillary wall thickening, erythrocyte diapedesis. In all the zones of the hippocampus significant increase in number of pyramidal neurons with the signs of injury was observed. The atrophic changes were demonstrated by the decrease in the average and relative areas of pyramidal neuron perikarya in all the hippocampal areas. Immunohistochemical study has shown the increase in serine racemase expression in CA1, as well as translocation of immunoreactive material into the processes of pyramidal neurons. In CA3 and CA4, a tendency to decreased expression of serine racemase was found. Conclusions. Following a long-term exposure of rats to gravitational overloads in caudo-cranial direction, all the hippocampal areas demonstrated the signs of damage combined with an enhanced expression and accumulation serine racemase in the dendrites of pyramidal neurons of the CA1 area, which may indicate the participation of excitotoxicity in the mechanisms of secondary damage in this area.

Objective - to study the morphometric characteristics of the right atrium (RA) and the interatrial (Bachmann) bundle (IAB) of the of the human heart in adults, with the purpose of installation of endocardial electrodes. Material and methods . Heart samples from 84 males and females of mature and old age who died from noncardiac pathology were obtained at autopsy and were examined using cardiometric methods, corrosion casting and plastination techniques. Results. Average IAB thickness was 5.1±0.7 mm, and average width - 15.3±3.1 mm. RA inferior-superior size was equal to 49.3±2.6 mm, transversal size - to 40.6±2.5 mm. The distance from the lateral margin of the ostium of the superior vena cava (SVC) to the top of the RA appendage (58.8±4.7 mm) was larger than the distance from SVC ostium to the IAB region (25.1±2.8 mm). The distance from the IAB to the compact part of the atrioventricular node (AVN) was, on the average, 17.9 mm shorter than the distance from the RA appendage to the AVN. Conclusion. During cardiac stimulation from IAB region, electric impulse will reach AVN quicker than that from the RA appendage, while implantation of an atrial lead into the IAB region is preferable from anatomical and electrophysiological points. It is shown that for positioning of a lead into IAB region, the stylet with a curvature of smaller diameter is required.

Objective - to verify the senescence markers of skin fibroblasts in in vitro model. Material and methods. The study was performed on cultured human skin fibroblasts of 3rd passage (“young» cultures) and 14th passage (“old” cultures). The expression of type I collagen, sirtuin-6 and matrix mettaloproteinase-1 (MMP-1) in skin fibroblasts cultures was examined using the method of immunofluorescence confocal microscopy. Results . It was shown that during cell aging, the expression of type I collagen and sirtuin-6 in skin fibroblasts cultures decreased 3.5 and 3.6 times respectively, while the expression of MMP-1 increased 2.5 times. Conclusions . It is suggested, that decreasing sirtuinn-6 expression results in the disturbances of type I collagen synthesis and increase in MMP-1 expression. This mechanism can play an important role in the understanding of molecular mechanisms of skin aging.

Objective - to study the peculiarities of structural changes of skeletal muscle in animal model of local hypertensive ischemic syndrome. Material and methods. Histological examination of thigh muscles from adult rabbits of both sexes was performed in normal animals and at various time intervals after application of a pneumatic tourniquet on the femoral upper third for 4 hrs under 80-100 mm Hg pressure (3 control and 14 experimental animals). Results. A pneumatic tourniquet with an exposure of 4 hrs caused thigh muscle edema, muscle fiber structural homogenization and contraction. Starting on day 7 after removal of the pneumatic tourniquet, the ischemic muscles were characterized by a progressive proliferation of connective tissue cells with the development of fibrous tissue and the intensification of degenerative changes in muscle fibers. Conclusions. Exposure of skeletal muscle of rabbit thigh to a local hypertensive ischemia for 4 hrs under 80-100 mm Hg pressure resulted in the development of scar-fibrotic degeneration of soft tissues, characteristic for ischemic syndrome.

Objective - to study the cytoarchitecture of the sensorimotor cortex (SMC) and CA1 field of the hippocampus of albino rat brain after severe traumatic brain injury. Material and methods . The polytrauma was modeled according to Noble-Collip method under the anesthesia. The main group (n=25) included animals with convulsive paroxysms (CP) and the comparison group (n=25) - rats free of them. The material was collected on days 1, 3, 7, 14 and 30 after the injury. The brain sections were stained with Nissl method, total numerical density of pyramidal neurons (TNDN) and the proportion of dark neurons (DN) were determined. Verification of statistical hypotheses was performed using Statistica 8.0. Results . One day after trauma, the number of DN was significantly increased in SMC and CA1 field of the hippocampus. In the late recovery period, in the comparison group 65.0% of DN in SMC restored to normochromic cells, while in CA1 field of the hippocampus this was found in 18% neurons. The emergence of CP prevented the restoration of DN: in SMC 54.5% of the neurons, and in CA1 field of the hippocampus - only 2.7% of the cells were restored. As a result, in the main group TNDN in SMC decreased by 32.4%, while in CA1 field of the hippocampus it was reduced by 55.6% and in the comparison group - by 24.7% and 43.3%, respectively. Conclusions. CP are a factor contributing to the pathological changes of neurons in the post-traumatic period.

Objective - to explore the possibility of application of immunocytochemical reaction to von Willebrand factor to analyze the localization of Weibel-Palade bodies in the venous endothelium using confocal laser microscopy. Material and methods. The study was performed on paraffin sections of human great saphenous vein (n=5). Results. A comparative study of preparations for light and confocal laser microscopy suggests that the confocal laser microscopy due to the possibility to achieve high resolution allows identification of the localization of the product in more detail, as well as to carry out a quantitative analysis. Conclusions. The presented set of reagents for immunofluorescent reaction provides high quality preparations, in which individual Weibel-Palade bodies are readily identifiable Application of the proposed set of fluorochromes for confocal laser microscopy allows easy separation of channels and the study of structures independently of each other.

Objective - to increase the accuracy of calculating the body surface area (BSA) on the basis of increased number of anthropometric parameters registered. Material and methods. The known formulas for the determination of human BSA based on body mass and length, were analyzed. The data obtained from the study of 59 men and 59 women, were used for a correlation-regression analysis of the dependence of BSA, calculated by the Mosteller formula, on the value of the generalized parameter equal to the body mass divided by body length and multiplied by the waist circumference. Results. It was shown that the formulas for determining BSA using only body mass and length can not reflect its dependence on the individual features of the body shape. The formulas for determining BSA of men and women using the measured values of body mass, length and waist circumference are proposed. Conclusions. The values of BSA, calculated from the formulas proposed, coincide with those determined from known formulas using only mass and length, only with standard ratios of mass, height and waist circumference. When human body parameters deviate from the accepted criteria of the norm, the proposed formulas give BSA values adequately reflecting these deviations.