[Renal morphological changes in experimental oxalate nephrolithiasis]. / Morfologicheskie izmeneniia pochki pri éksperimental'nom oksalatnom nefrolitiaze.

AIM: Тo evaluate renal morphological changes in the early stages of lithogenic processes and during urinary correction of urine with oxalate-chelating compounds (sodium citrate). MATERIAL AND METHODS: An experimental model of oxalate nephrolithiasis was performed on 80 male Wistar rats weighing 180 to 250 g. Rat kidneys were morphologically and ultrastructurally studied. Immunohistochemical techniques were applied to study the features of development of endoplasmic reticulum stress. RESULTS: There were histotopographic changes in the renal tissue elements in the early stages of development of lithogenic processes accompanied by characteristic ultrastructural changes in the epithelium of the renal tubules and collecting ducts: by expansion of elements in the granular endoplasmic network, by mitochondrial damage with formation of large, ampullary extended cristae, and by emergence of autolysosomes. Signs of development of endoplasmic reticulum stress with activation of protein GADD153 were found, which deteriorated the cell lining of the nephron tubules and collecting ducts. CONCLUSION: In the early stages of development of lithogenic processes, there are stereotypic ultrastructural and histotopographic changes in the epithelium of the nephron tubules and collecting ducts, which contribute to the progression of stone formation processes and to the disruption of cellular homeostasis with activation of endoplasmic reticulum stress, synthesis impairment, or post-translational modifications in modulator proteins of lithogenesis.

Thymus in experimental carcinogenesis of the prostate gland.

We studied structural changes in the prostate gland, thymus, and lymph nodes in CBA mice after transplantation of Ehrlich ascites tumor cells into the prostate gland. On experimental day 5, the number of blood and lymph vessels decreased in the gland; the percentage of connective tissue elements and glandular tissue and the number of immunoblasts in the thymus increased. On day 18, the number of blood vessels in the tumor decreased; the width of the cortex and glandular tissue increased in the thymus, while the number of immunoblasts was reduced. On day 28, tumor infiltration and increased number of lymphatic vessels in its stroma were observed; parenchyma was reduced, and the area of the connective tissue increased in the thymus. These structural changes indicated the development of accidental involution of the thymus during carcinogenesis of the prostate.

Stimulation of angiogenesis in rat ischemic limb by intramuscular implantation of mononuclear fraction cells from autologous bone marrow.

We studied angiogenic effects of two variants of indirect revascularization (transplantation of mononuclear fraction cells from autologous bone marrow alone or in combination with laser tunneling) after modeled ischemia of the lower limbs in rats. Doppler sonography and immunofluorescence studies showed that intramuscular implantation of isolated fraction of autologous bone marrow mononuclear cells in combination with laser tunneling of the muscles is most effective and can be recommended as a method of angiogenesis stimulation in non-reconstructable distal vascular pathology of the extremities.

[Myocardial regeneration: proliferative potential of cardiomyocytes and induction of cardiomyogenesis in alterative and plastic cardiac failure].

The authors present data on the character and manifestations of regenerative reactions of cardiomyocytes at alterative and plastic cardiac failure, propose morphological criteria for the assessment of cardiomyocyte regenerative potential, and consider the possibility to induce cellular forms of cardiomyocyte regeneration in patients with cardiomyopathies and in the post-infarction period. The quantitative morphological study showed that absolute number of cardiomyocytes and the ratio of their mono- to binuclear forms are the most informative criteria of regeneration of these cells affected by cytotoxic and biologically active agents. Populations of mononuclear cardiomyocytes are believed to play the key role in the maintenance of myocardium regenerative capacity. Morphological equivalents of cardiomyocyte proliferative activity and main forms of regeneration of muscular fibers exposed to cytotoxic factors are described. Studies on induction of myocardial regenerative reactions in the post-infarction period revealed major morphogenetic effects of endothelial growth factor and mononuclear marrow cells implanted in the myocardium.

Morphological and molecular analysis of angiogenesis after intramyocardial transplantation of autologous bone marrow mononuclear cells.

We studied the peculiarities of angiogenesis in the postinfarction period after transmyocardial laser revascularization and intramyocardial implantation of mononuclear bone marrow cells into the pericicatrical zone of the left ventricular myocardium in dogs. Morphological manifestation of angiogenesis in the myocardium after application of laser and cell technologies are angiomatosis, formation of large thin-wall vessels and sinusoids. The angiogenic effect of implanted mononuclear bone marrow cells is determined by high content (43-47%) of CD31+ cells in both adherent and nonadherent fractions. More pronounced angiogenic potential of nonadherent cells is determined by intensive expression of cytokine VEGF-B and D mRNA essential for arterial vessels growth. Immunohistochemical studies showed that about 90% cells of the nonadherent fraction are endothelial precursors expressing endothelial cell markers isolectin B4 and VEGF-R2. It was found that the use of adherent mononuclear bone marrow cells during the postinfarction period induces ossification of the epicardium and subepicardial myocardium layer, formation of cartilage plates, and focal calcification. Implantation of nonadherent mononuclear bone marrow cells into transmyocardial laser channels did not induce ectopic ossification of the myocardium.

Structural and molecular reorganization of cardiomyocytes in transposition of the main vessels.

Studies of myocardial autopsy specimens from infants (0-12 months) with transposition of the main vessels showed the formation of a complex of compensatory adaptive, degenerative, and destructive changes, manifesting at a tissue level in cardiomyocyte heterogeneity and formation of cardiosclerosis zones. Cardiac myosin synthesis was replaced by synthesis of skeletal myosin, which was detected at the molecular level. Clinically it manifested in the progress of heart failure. Hyperplastic processes (intensive polyploid transformation of the nuclei) play an important role in heart remodeling in patients aged over 6 months. The findings of immunohistochemical and fluorescent studies seem to be prognostically important and provide more accurate data on the pathological processes in the myocardium at the initial stages of heart disease development starting from birth.

Laser-induced fluorescence and X-ray spectral analysis of carious process in hard dental tissues.

Morphological and spectral X-ray analysis of carious and noncarious extracted teeth showed the patterns of dentin ossification in caries of different degree. Parietal ectopic ossification of the canal and cavity lumens in stages III and IV dental caries is regarded as a specific structural marker of pathological regeneration. The X-ray spectral analysis showed that the progress of carious process is paralleled by loss of mineral components. Laser-induced fluorescent study of tissues in extracted teeth showed 4 spectral bands corresponding to mineral and protein components of the tooth. The progress of carious process was associated with reduction of the fluorescence intensities of the spectral bands characteristic of dental collagen and mineral components.

[Micro- and ultrastructural characteristics of liver and nuclear endonuclease activity in hepatocytes after the combined exposure to industrial frequency magnetic field and continuous illumination].

The effects of combined action of the industrial frequency magnetic field (MF) and continuous illumination (CI) on microcirculation, ultrastructural features of liver cells and apoptosis were studied in Wistar rats (n=56). It was found that in the liver of rats exposed to MF, CI and CI+MF for 14 days, parenchyma relative area was reduced, and that occupied by the sinusoidal capillaries was increased together with the liver vascularization coefficient. Combined exposure resulted in most pronounced ultrastructural changes (plasma membrane lysis in hepatocytes and endothelial cells, doubling of osmiophilic layers in tight intercellular junctions). Hepatocytes revealed condensed cytoplasm, mitochondria with electron-dense matrix, nuclear chromatin disintegration and nucleolar compaction. Hepatocyte intranuclear endonucleases were activated.

Angiomatosis and ectopic ossification in the dog myocardium after intramyocardial implantation of autologous bone marrow mononuclears in experimental coronary disease.

Disseminated ossification of the myocardium and severe angiomatosis were detected in sites of implantation of unseparated bone marrow mononuclear fraction cells in dogs with experimental chronic coronary disease. Minor immunocytochemical differences in cells of the mononuclear fraction adhering and not adhering to plastic were found. Significant differences in the expression of mRNA of chondro-osteogenesis genes (aggrecan, lumican, and osteopontin) in adherent and nonadherent cells were detected. The expression of aggrecan gene mRNA was 3-fold lower, of lumican gene 6-fold, and of osteopontin gene 11-fold lower in nonadherent cells compared to adherent fraction.

Immunohistochemical study for the expression of Bcl-2 family proteins in Walker 256 carcinosarcoma cells under the influence of cytostatic drugs.

Immunohistochemical study was performed to evaluate the expression of Bcl-2 family proteins (Bcl-2, Bax, and Bad) in Walker 256 carcinosarcoma cells after implantation into the thigh muscle of male Wistar rats (10(6) cells). The experiment was conducted under conditions of spontaneous tumor development and individual or combined treatment with melatonin and cyclophosphamide. The use of melatonin as monotherapy or in combination with cyclophosphamide was followed by a significant decrease in Bcl-2 expression in carcinosarcoma cells. The Bcl-2/Bax and Bcl-2/Bad ratio was significantly reduced under these conditions (particularly after combined treatment with cytostatic drugs). These changes were accompanied by a significant (by 93.61%) decrease in the volume of transplantable tumor on day 14. Daily treatment with melatonin was accompanied by significant changes in the structure of Walker 256 carcinosarcoma. It was manifested in the formation of connective tissue septa and pseudofollicles.

Morphological evaluation of cytoarchitectonics of aortic graft at the biotechnological stage with analysis of changes in laser-induced fluorescence spectra.

We performed a fluorescent microscopic examination of human and animal aortic grafts at different stages of decellularization. Treatment of aortic grafts with trypsin/EDTA solution for 48 h leads to their complete decellularization and preserved the connective tissue fiber backbone, which gains a netlike structure. The use of this protocol of decellularization leads to disappearance of subintimal calcium deposits in human aortic grafts. Differences in laser-induced fluorescence spectra of aortas before decellularization and at different stages of this process were revealed. Our findings suggest that the use of fluorescence induced by excimer lasers is promising for identification of the composition of biological tissues, analysis of their state, and the presence of changes.

Cardiomyocyte regeneration in pericicatricial zone of the myocardium after laser tunneling and implantation of bone marrow mononuclear cells.

Using canine model of chronic postinfarction myocardial ischemia we evaluated angiogenesis and cardiomyogenesis after combined revascularization by laser tunneling of the pericicatricial zone followed by implantation of bone marrow mononuclear cells into the channels. It was shown that the numerical density of arterioles and capillaries considerably increased 1 month after revascularization. We also observed a considerable increase in the density of cardiomyocyte nuclei in the test area, a 2-fold increase in the total area of nuclei, and an increase in the mean area of cardiomyocyte nuclei. The number of PNCA-positive cardiomyocytes significantly increased after combined revascularization. Our findings suggest that combined revascularization of the pericicatricial zone of the myocardium promoted angiogenesis and stimulates regeneration of cardiomyocytes.

Hemolymphomicrocirculatory bed of the pancreas during acute experimental pancreatitis.

Histochemical study of rat pancreas was carried out on days 14 and 30 of acute pancreatitis. The area of the stroma increased after damage and the area of lymph microcirculatory component increased in comparison with the blood circulation component.

[Morpho-functional changes of liver and its regional lymph nodes after exposure to magnetic field of industrial frequency].

The aim of this research was to study the morpho-functional organization of liver and its regional lymph nodes, as well as of other organs of immune system, in animals exposed for 14 days to a magnetic field of industrial frequency (MFIF) with aperiodic oscillations of amplitude of magnetic induction in the range of 5-10 _Ts. The methods of light and electron microscopy were used. Damage to DNA in hepatocyte nuclei was determined using ethidium bromide. Quantitative analysis of the cells in the organs of immune system was performed, blood leukocyte formula was calculated and the activity of oxidative enzymes in blood cells was determined. It was found that MFIF caused micro- and ultrastructural changes in animal liver and its regional lymph nodes, which included the disturbances of hemo- and lymphocirculation, destruction of cellular membranes in some cells, dilation of rough endoplasmic reticulum cisterns, appearance of degenerate mitochondrial forms, glycogen depletion, that collectively indicated the development of tissue hypoxia. The increase in the activity of nuclear endonucleases was detected. Response of organs of immune system to MFIF was manifested by shifts of blast forms/ mature lymphocytes ratio in hepatic regional lymph nodes and by the changes of energy metabolism of blood lymphocytes.

[Experimental evaluation of delivery means of potential anti-HIV microbicides]. / Eksperimental'naia otsenka sredstv dostavki potentsial'nykh anti-VICh-mikrobotsidov.

The purpose was to develop an effective drug of local intravaginal membranetropic microbicide based on polycarboxylate and matrix modified by norbonene and/or peptide (simulator of CCR5 coreceptor). The drug was added to the composition of polyacrykic acid-polyvinylpyrrolidone (interpolymer complexes) in order to prevent the interplay of its non-specific groups with proteins. The antiviral effect and absence of toxicity of the finished microbicide form were demonstrated on the human lymphoid MT-4 culture.

Influence of mineral components on laser-induced fluorescence spectra of calcified human heart-valve tissues.

Laser-induced fluorescence (LIF) spectra of calcified human heart-valve tissue and LIF spectra of macroscopic calcinosis fragments dissected from human heart valves were compared with LIF spectra of pig myocardium tissues. Excitation was provided by an excimer laser with wavelength lambda = 248 nm. Fluorescence bands that were due to mineral and organic tissue components were identified by measurement of LIF spectra of macroscopic fragments of calcified tissues that had been heat treated at 700 degrees C. The studies showed that LIF spectra of calcified tissues include fluorescence emission from tryptophan, collagen, elastin, and a mineral component of tissue, hydroxylapatite. The observed differences in LIF spectra of normal and calcified tissues with different pathologies may result not only from calcification-induced changes in relative collagen and elastin concentrations but also from additional (absent in normal heart tissue) fluorescence of hydroxylapatite. The calcification-induced changes in the LIF spectra of human heart-valve tissues, characterized by a 330/450 nm ratio, were found to be quite appreciable, which suggests that this ratio can be used with LIF measurements to evaluate the degree of heart-tissue calcification.