MORPHOLOGICAL CHANGES OF THE HEPATIC PORTAL TRACTS IN EXPERIMENTALLY INDUCED CHOLESTASIS.

The dynamics of morphological changes developed in liver and bile ducts in biliary obstruction are well studied in the animal models of biliary obstruction, however,the data on the morphology of the portal tracts are scarce. The aim of the research was to study the structure of the portal tracts and interrelationship of their structural components in experimental biliary obstruction. The investigation was conducted on albino Wistar rats weighing 200-250 g, undergone biliary obstruction by common bile duct ligation (CBDL). The histological, histochemical and immunohistochemical investigation of the liver tissue stained with Hematoxylin& Eosin, Masson's trichrome and marked with CK8antibody were performed on the 3rd, 6th and 12th days after CBDL. The CBDL-induced biliary obstruction triggers a systemic reaction of the bile ducts and a complex of accompanying reactions that is heterogeneous, depending on the caliber of both the bile ducts themselves and the portal tracts containing them.CBDL causes dilation of the large bile ducts, their pressure on the portal veins with the deformation of their lumens, changes in the architectonics of the portal tracts, and expansion of the portal areas accompanied by increasing portal fibrosis and ductular reaction. The small bile ducts are less prone to dilation under CBDL conditions but actively proliferate and penetrate widely into the parenchyma of the liver lobules. Based on this ductal reaction, fibrosis of increasing intensity develops, which connects the adjacent portal tracts as well as the portal tracts and the connective tissue sheaths of the thin tributaries of hepatic veins. In the conditions of such fibrosis, it is difficult to identify the individual portal tracts of small caliber and, moreover, to clarify the relationship between their elements.

LIVER EXTRACELLULAR MATRIX PECULIARITIES IN MAMMALS AND AVIANS.

Analysis of liver matrix studies makes it obvious that knowledge about the connective tissue skeleton of the liver is not systematized, the terminology is contradictory, and the question of the construction of some components sometimes causes controversy. We set a goal to study the features of the construction of the connective tissue matrix of the liver of various mammals and birds in order to identify and systematize general and specific patterns of this structure. The liver of mammals with a gallbladder (pigs, sheep) and without a gallbladder (rats) and birds (domestic chickens with a gallbladder) was studied by the methods of anatomical preparation, histology, histochemistry, histotopography, immunohistochemistry, scanning electron microscopy of corrosion replicas and fluorescence microscopy. In the liver of mammals and birds, connective tissue membranes of various thicknesses and compositions around the portal tracts and hepatic veins are revealed. These membranes are connected in various ways with each other, the liver capsule and the intralobular network of connective tissue and form an extracellular matrix, which strengthens the structure of the liver tissue and helps the organ maintain its integrity in various pathological conditions.

[; ADAPTATION OF THE BILE DUCTS OF THE PORTAL TRIAD IN CASE OF MECHANICAL CHOLESTASIS (REVIEW)].

In case of mechanical cholestasis, along with stagnation in the veins and bile ducts, lymph production increases, which contributes to the accumulation of ascitic fluid. In the peribiliaryareas, where the extramural biliary glands are located, an accumulation of lymphatic vessels has been observed in all the preparations.In these same areas, a contrast-enhanced microtomography showed transition of the ink-gelatin contrast agents (using gelatin and India ink) from the extramural part of the mucous glands to the lumen of the lymphatic capillaries and blood vessels.Lymphobiliary connections were visualized during the preparation of the sections of the portal triad of the lobar and sectoral portal tracts under a binocular microscope. More reliable evidence of the existence of lymphobiliary connections in the portal triad region was revealed on histological preparations stained with traditional methods.; Thus, anatomically, the area of the portal triad appears to be one of the alternative areas of lymphobiliary communications, which further confirms its high adaptive capacity in case of stagnation of bile.

CHALLENGES AND MANAGEMENT OF CONGENITAL ABDOMINAL WALL DEFECTS (REVIEW).

Management of congenital abdominal wall malformations is still a challenge in paediatric surgery due to visceroabdominal disproportion, large defects of abdominal wall and immature abdominal cavity. Most of the patients treated with primary closure need artificial substitutes like patches or biomaterials for non-permanent abdominal wall closure. Patches represent the source of constant infections and complications like separation of prosthesis from fascia. Removal of these patches and ventral hernia repair is essential afterwards. As for component separation technique, this method helps to restore normal anatomy of anterior abdominal wall, results in good cosmetic appearance, requires only one-stage operation procedure, minimal skin flap advancement and is associated with lower infection risk. Although, while performing component separation technique, perforator branches of epigastric artery (periumbilical perforators) are damaged and puts the vascularization of the skin at the risk. Only pudendal artery branches and intercostal arteries are left to supply the skin with the blood, which from our point of view is insufficient. Accordingly, for successful treatment of congenital abdominal wall defects, further research in order to develop new operation techniques, as well as search for the ideal biomaterials for the closure of the large defects of anterior abdominal wall is essential. These biomaterials should possess unique biological properties that are important for tissue repair, including anti-inflammatory, antimicrobial, antifibrosis, antiscarring, as well as a reasonable cost and low immunogenicity.

COMPARATIVE ANALYSIS OF WHOLE CARTILAGE TISSUE THERMOSTABILITY IN DISEASED PATIENTS VERSUS INJURED PATIENTS.

We conducted comparative thermodynamic analysis of femoral cartilages tissue of injured (healthy) patients and patients with congenital hip dislocation. It is shown, that temperature which corresponds to maximum of heat absorption peak of femoral cartilages tissue of diseased patient is on 6.4oC lower than heat absorption peak of femoral cartilages tissue of healthy patient. Heat absorbed during denaturation process in all these cases are close to each other with experimental error accuracy and corresponds to 52±2.6, 51±2.6 and 50±2.5 J/g of dried biomass accordingly. Analysis of the published data makes it possible to assert that the dominant heat absorption stage on DSC curves of tested fresh tissues samples is associated with melting of collagen fibers, hence the thermal stability of the collagen fibers in the patient's tissue is reduced relative to norm.

MORPHOLOGICAL CHANGES OF RAT PLACENTA IN DIFFERENT PERIODS OF PREGNANCY UNDER MODELED PREECLAMPSIA.

The purpose of the study was to determine the morphological changes of rat placenta in II, III week of pregnancy under modeled preeclampsia. Modeling of preeclampsia was performed in the rats, as follows: lumen of the abdominal aorta below the renal artery was narrowed by the silk tread on the third of its diameter (0.2 mm). The placenta tissue was studied by histological and immunohistochemical methods (AE1/AE3, CD133, Ki-67). The study has shown that in the experimental model of preeclampsia at the end of II, III week of pregnancy the number of glycogen cells in the placenta trophyspongium layer is reduced compared with the control. There was shown sharp dilatation of the blood sinuses and lacuna, sometimes along the events of stasis. The volume of nucleated erythrocytes in fetal capillaries of the labyrinth layer is reduced compared with the control, especially in IIIweek of pregnancy. In the preparations marked by the CD133 marker, unlike to the norm of III week of pregnancy, the visualization of positive endothelial cells is complicated. The study of the preparations marked by Ki-67 marker reveals that the proliferated activity in the hypoxic placenta tissue is sharply reduced. The exception is those blood tubes, to which umbilical blood vessels are finally formed. It can be concluded that due to hypoxia placenta proliferation of placental blood vessels is disturbed that contributes to the disorder of placental blood circulation, reduce its metabolism in complications of pregnancy.

[Alterations in populations of T-lymphocytes in the rats blood during experimental preeclampsia].

Immune tolerance to the fetus is predetermined mainly by HLA-G expression in trophoblasts, varying the ratio of Th1 / Th2, decrease in the content of cytotoxic T lymphocytes and natural killer cells (NK cells) and fusion "tread" of antibodies. The aim of the study was to establish the role of the placental hypoxia in regulation of expression of -lymphocytes populations in the blood of rats at different stages of pregnancy. For the purpose of modeling of PE in pregnant rats, at10-th day of gestation the lumen of the abdominal aorta below the renal artery was narrowed by the silk thread a third of its diameter (0.2 mm). In blood serum was defined the relative content of leukocyte subpopulations by indirect immunofluorescence in cytotoxic assay using monoclonal antibodies to CD4, CD8, CD14, CD16 leukocytes («ICN Pharmaceutical¼, USA). The study found that in the blood of animals of control group (phisiological pregnancy) within the 2nd 3rd trimester of gestation of CD4, CD8 subpopulations of lymphocytes did not change. The animals of the experimental group (pregnancy complicated by placental hypoxia) content of CD8 subpopulations and CD16 (NK cells) in the blood did not change significantly compared with those in the blood of animals in the control group, whereas CD4 T cell subpopulation in the second and in the third trimester statistical significantly decreased compared with those in control group (p<0.001). The ratio of immunoregulatory subpopulations lymphocytes CD4/CD8 decreased, number of CD14 (monocytes) phenotypes leukocytes increased. It is concluded that the placental hypoxia promotes disorder of the regulation of the immune balance of the mother's body during pregnancy, which is manifested in decrease ratio immunoregulatory subpopulations of lymphocyte, increasing the intensity of local expression of monocytes.

[Alterations of immunebalance in the rats blood during experimental preeclampsia].

The aim of the study was to establish a violation of hormonal (progesterone and estradiol) and immune balance (interleukins IL-2, IL-10, TNF-α) in the rats blood at different stages of experimental PE induced by hypoxia placenta. For the purpose of modeling of PE in pregnant rats, at 10-thday of gestation the lumen of the abdominal aorta below the renal artery was narrowed by the silk thread a third of its diameter (0.2 mm). Blood for the study was taken at the18thand25th day of pregnancy. In the blood content of interleukins(IL-2, IL-10, TNF-α) and the concentration of progesterone and estradiol by immunoenzymaticassay were measured. A results of research established that with increasing of the gestational age in the rats with experimental PE estradiol and progesterone content in the blood increased much slower than in the control animals. At the same time in the blood of pregnant rats with placental hypoxia in the second trimester TNF-α level was by 80% higher and the level of IL-10 was 30% lower than in the control animals. With the increase of gestational age (in the third trimester) in animals of the experimental group blood content of IL-2 and TNF-α increased sharply (by 50% and 30%), whereas the level of IL-10 did not change compared with baseline values. In the control group of animals, alterations in the cytokines content were much slower. It was concluded that violation of the synthesis of progesterone in hypoxic placenta and its insufficient content in the blood during pregnancy is one of the causes of disorders of the immune balance in the body of pregnant rats. Observation of the dynamics of progesterone in the blood during pregnancy may be informative for the early diagnosis of PE and its timely treatment.

Extracellular matrix thermostability of breast gland carcinoma.

Thermostability of epithelial cell matrix in composition of normal and breast ductal carcinoma tissues at various stages of the disease has been studied in the temperature range 40-90°C with help of differential scanning calorimeter (DSC). It has been shown that the denaturation process has three stages of transition in both cases. The temperatures corresponding to maxima of these structural transitions (Td) in case of normal and ductal carcinoma tissues equals to 55 , 66,78 C and 48, 55, 60, 85°C, respectively. Denaturation enthalpy (∆Hd) reflects contribution of hydrogen bonds, electrostatic and hydrophobic interactions in stability of native structures of biomacromolecules; in case of normal tissues, it equals 68,5±6.0 J/g dry biomass and decreases up to 52.5±6.0 J/g dry biomass in stage III of the disease. On the basis of presented and published experimental data, it is affirmed that the dominant transitions with Td around 66 and 60°C in case of norm and carcinoma, accordingly, correspond to denaturation of collagen IV fibers--the main component of microenvironment of duct epithelial cells (ECM)--and weakly expressed transition stages at 55, 78, 85°C correspond to denaturation of cytoplasmatic proteins. It is supposed that the observed significant differences in thermostability, in particular, 6° decrease of the ECM main component collagen, 7° increase of cytoplasmic proteins, and a significant decrease of total ∆Hd in case of ductal carcinoma compared to norm may be used as a new express test together with other existed tests for diagnosis of breast cancer at early stage of disease using some mg quantities of biopsy tissue.

[Morphological changes in brain and heart after the temporary liver exclusion from the bloodstream during the cholestasis].

The aim of the study was the detection of the peculiarities of the changes in brain and heart, developed by the cholestasis after ischemia (due to the temporary liver exclusion from the bloodstream) and post-ischemic restoration of bloodstream. The experimental study was carried out on 12 mature rats (weight 150-200 g). After the creation of 5 day cholestasis pattern, the exploration and clamping of the hepato-duodenal ligament was done for 10 minutes. After the 15 minutes, 24 hours and 48 hours of the clamp withdrawal from the portal complex, the pieces of the heart and the brain were investigated. The aether narcosis was applied for the anaesthesia purpose. The changes peculiar to the brain damage (perivascular and pericellular swelling, proliferation of glia and neurophagia) were observed shortly after the removal of the ischemia. The mentioned changes were dramatic after 24-48 hours of experimentation. The study suggests that the dramatic changes were developed in the brain and cardiac tissues after 15 min. of the experimentation. Mentioned changes are dismetabolic processes and they continuing in the later terms, including the 48 hours later of the experimentation.

[Common intralobular microcirculatory module peculliarities in cholestasis in white rats].

The dynamics of intralobular microcirculatory module transformation in cholestasis was investigated. The liver tissues of 54 white Wistar rats were studied by Histology, TEM, TEM after injection of 1% Pb(NO(3))(3), vie common bile duct (CBD), SEM of corrosion casts prepared after methylmethacrylate injection vie CBD. It is demonstrated that liver is the basis of microcirculation of 4 different liquids: blood, bile, connective tissue liquid and lymph. Accordingly, in normal condition 4 different well formed compartments bordered from each-others by different types of cells exist. In the yearly stages of cholestasis (3-6 days) the function of bile drainage is partially overtaken by lymph pathways. This is accompanied by the beginning of the destruction of structures bordering above-mentioned microcirculatory beds. In the later stages of cholestasis (12-18 days) the final disorganization of microcirculatory compartments with mixture of all liquids is observed. It is accompanied by increased dystrophy of liver cells population.