[Analysis of the inflammatory processes in the diffuse thickening of the intima of human aorta].

It is generally recognized that the accumulation of lipids and immuno-inflammatory cells are early signs of atherosclerosis. In the present study, we have investigated the relationship between the deposition of lipids, of immuno-inflammatory cells and the expression of HLA-DR molecules (a marker of immune activation), the molecules of the class II of major histocompatibility complex (MHC) in diffuse thickening of the intima (DIT). Lipids, including triglycerides, cholesterol esters, free cholesterol and phospholipids were studied by chromatography, Oil Red O histochemisty, as well as by electron microscopic analysis. Immuno-inflammatory cells and the expression of HLA-DR were investigated by immunohistochemistry in consecutive section of the same tissue samples. It has been shown that the lipids were unevenly distributed in DIT. In juxtaluminal sublayer, lipids were detected both in the cytoplasm of intimal cells and extracellularly. In the juxtamedial musculoelastic sublayer of the intima, lipids were present predominantly along elastic fibers. The positive correlation between the presence of lipids and the expression of HLA-DR was revealed (r = 0.79; P < 0.001). Also, a positive correlation was found between the deposition of lipids and the number of immune-inflammatory cells, although correlations was different for different sublayers of the intima. In particular, the correlation between the deposition of lipids and immune-inflammatory cells in the juxtaluminal sublayer of the intima was higher (r = 0.99; P < 0.001) than in the juxtamedial musculoelastic layer (r = 0.28; P < 0.001). These data support the hypothesis that postulates that the accumulation of lipids in the intima is a key factor in the initiation of inflammatory reactions. At the pre-atherosclerotic stage of the development of this disease, earlier pathological processes associated with lipid-dependent activation of immune cells occur mainly in the juxtaluminal portion of the intima.

[Dendritic cells and their role in immune reactions of atherosclerosis].

Dendritic cells were discovered and recognized as antigen-presenting cells in 1973. Since then, large volume of information has accumulated showing role of dendritic cells as a key element connecting the innate and adaptive immunity. Nowadays, dendritic cells are considered to be professional immune sensors capable of recognizing both antigen amounts and antigen persistence via complex mechanisms that involve decoding and integration of various signals received in a receptor-dependant manner. Tissue microenvironment plays an important role in the modulation of effector functions of dendritic cells leading either to activation or to suppression of immune reactions. Dendritic cells maintain the homeostasis and are involved in a number of diseases including infection diseases and cancer. The presence of dendritic cells in arteries has been reported in 1995. And since then the importance of dendritic cells in atherogenesis is intensively studied. This review briefly described current knowledge on dendritic cells and their role in atherogenesis.

[Numbers of cells and cell proliferation in intima of different human arteries].

Increased cell proliferation in early atherosclerotic lesions is recognized as an essential event of atherogenesis but the levels of cell proliferation in different stages of atherosclerotic plague formation in different types of human large arteries are still insufficiently studied. In the present work, we studied intima thickness and proliferation of newly "infiltrates" hematogenous and resident cells in atherosclerotic lesions of the carotid and coronary arteries and compared these parameters with those in the aorta, reported by us in earlier publication. Analysis of intima thickness and proliferation in grossly unaffected intima and in different types pf atherosclerotic lesions (initial lesions, fatty streaks, lipofibrous, plaques, and fibrous plaque) revealed that although there were similar tendencies in the change of the infiltration levels of hematogenous cells and proliferation in different types of arteries, there were significant quantitative differences between different types of arteries. Hematogenous cells in lipofibrous plaques of the coronary and carotid arteries were found to account for a third and almost for a half of the total cell population, respectively, while atherosclerotic lesions in the aorta, as it has been shown by us earlier, to contain no more than 15% ofhematogenous cells. This suggests that the contribution of hematogenous cells to the development of atherosclerosis in the carotid and the coronary artery appears to be more significant than that in the aorta. Despite the differences in numbers of accumulating hematogenous cells in the intima, a similar "bell-shaped" dependence of cell numbers on the lesion type, involved in the following sequence: unaffected intima-initial lesions-fatty streaks-lipofibrous plaques-fibrous plaques, was detected in the coronary and carotid arteries. The visualization of proliferating cells (PCNA-positive) in atherosclerotic and unaffected zones of the coronary and carotid arteries revealed similar patterns. The maximum numbers of PCNA-positive resident cells were identified in lipofibrous plaques. The changes in the total cell numbers were accompanied by the changes in the numbers of both proliferating resident cells and proliferating hematogenous cells.

[The production of "pure" cultures of neurons from the brain of human embryos]. / Poluchenie "chistykh" kul'tur neironov golovnogo mozga émbrionov cheloveka.

A method has been developed for preparing essentially pure primary cultures of neurons from 10-12 week old fetal human brain. This method is based on the 1) capacity of neurons to form multicellular aggregates, 2) cultivation in chemically defined medium, and 3) treatment with cytosine arabinoside as antimitotic agent. This procedure allowed the preparation of highly purified (95 per cent and more) neuronal aggregate cultures. Ultrastructural analysis of these cultures following one and 8 days has revealed their partial differentiation during cultivation.

[The distribution of glutamate receptors in cultures of the motor area of the rat cerebral cortex studied by an immunoelectron microscopic method]. / Issledovanie raspredeleniia glutamatnykh retseptorov v kul'turakh motornoi zony kory golovnogo mozga krys immunoélektronno-mikroskopicheskim metodom.

The aim of the study was to analyse the distribution and localization of glutamate receptors in the cultured cells of the neonatal rat motor cortex, using immunoelectron microscopic technique, and monoclonal antibodies preliminary labeled with colloidal gold. Monoclonal antibodies against glutamate-binding proteins of the adult rat cerebral cortex were produced by means of hybridization of immune splenocytes with plasmocytoma cells. It was found that monoclonal antibodies labeled with colloidal gold could reveal selectively the localization of glutamate receptors on the membranes of neurons. Glutamate receptors were detected on differentiating neuron membranes only, being absent from the glia cell surface.

[An electron microscopic study of neuronal development in organotypic cultures of the anlage of the cerebral cortex from a human embryo]. / Elektronno-mikroskopicheskoe issledovanie razvitiia neironov v organotipicheskikh kul'turakh zakladki kory golovnogo mozga émbriona cheloveka.

Data are provided on cytodifferentiation of the cerebral cortex cultured cells taken from 10-12 week old embryos of man. It is shown that low differentiated neuroblasts well survive in culture for 21 days. Mature granular cells and middle pyramidal neurons are revealed in cultures. The number of morphological criteria may testify to the maturity of neurons: the presence of the Nissl substance, differentiation of dendrites and axons; the presence of various types of synapses. The absence of myelinized fibres testifies to the insufficient maturity of the cultures, that is probably associated with employing the low differentiated nervous tissue for cultivation and with insufficient cultivation period.

[Astrocyte death in organotypic cultures of fetal spinal cord from rats with unilateral micromelia]. / Gibel' astrotsitov v organotipicheskikh kul'turakh spinnogo mozga plodov krys s odnostoronnei mikromeliei.

Growth and differentiation of neurons and glia in spinal cord explants of 16 days old rat fetuses with teratogen-induced left-sided micromelia were studied. Progressive destruction of astrocytes that differentiate in interstitial zone of cultures was observed in 37% of explants of the left side, while the development was normal in cultures of the right side. Possible mechanisms leading to destruction of astrocytes in cultures of spinal cord regions that innervate anomalous limbs are discussed.

[Structural analysis of the interaction of low density lipoproteins with arterial intima cells in atherosclerosis]. / Strukturnyi analiz vzaimodeistviia lipoproteidov nizkoi plotnosti s kletkami intimy arterii pri ateroskleroze.

Structural characteristics of low density lipoprotein (LDL)-intimal cellular element interaction were studied in atherosclerotic lesions in the aortas obtained from rabbit with experimentally induced hypercholesterolemia and in human coronary arteries. An electron microscopic autoradiographic examination using 125I to study the in vivo interaction between LDL and rabbit aortic intimal cells indicated that the formation of foam cells was associated with activated endocyte activity and uncontrolled capture of atherogenic lipoproteins. The structural analysis of the interaction of native and modified LDL labelled with colloid gold, on the one hand, and human coronary intimal cells, on the other, was made by using ultrathin sections. This enabled the localization of the receptors to lipoproteins to be established. This also demonstrated that transformation of the cells to foam ones was due to the functional insufficiency of lysosomal activity and to the filling of the cytoplasm with membranelles and membrane-surrounded lipid vacuoles.

[Structural and functional characteristics of endothelial surface of the aorta in experimental hypercholesterolemia]. / Strukturno-funktsional'naia kharakteristika poverkhnosti endoteliia aorty pri eksperimental'noi giperkholesterinemii.

Structural and functional characteristics of the surface of aortal endothelium in experimental hypercholesterolemia in rabbits are presented. Scanning and transmissive electron microscopy showed deendothelization of the aorta to be a secondary factor due to activation of nonspecific endocytosis of lipoproteins. Microatheromas with parietal adhesion of thrombocytes and monocytes were found to form in the very early stages of formation of experimental atherosclerotic changes in the rabbit aorta.

[Structuro-functional characteristics of the human coronary arteries in atherosclerosis]. / Strukturno-funktsional'naia kharakteristika vnutrennei poverkhnosti koronarnykh arterii serdtsa cheloveka pri ateroskleroze.

Structural features of the endothelium interaction with the blood cellular elements during atherosclerotic processes of varying severity in the coronary arteries have been analyzed from the data of early sections and coronary artery biopsy specimens. The status of the endothelium has been uniform in macroscopically unchanged sites irrespective of the coronary atherosclerosis severity. A stable characteristic symptom of the initial stages of atherogenesis is the formation of crater-like defects and monocyte adhesion. Scanning electron microscopy has shown for the first time the presence of echinocytes in the blood of coronary patients and adhesion of these cells at the site of the endothelial monolayer destruction. The formation of microthrombi at the site of endothelial destruction is not a stable symptom of the initial stages of atherogenesis. Endothelial destruction and regeneration, aided by the platelets, can be observed at all stages of atherogenesis.

[Stereological analysis of the nonspecific endocytotic uptake of lipoproteins by aortic endothelium in the initial stages of experimental atherosclerosis in rabbits]. / Stereologicheskii analiz nespetsificheskogo éndotsitoznogo zakhvata lipoproteidov éndoteliem aorty v nachal'nykh stadiiakh éksperimental'nogo ateroskleroza u krolikov.

Stereological analysis of vesicular transport of low density lipoproteins was performed by electronograms of the aorta endothelium from 42 rabbits in the course of experimental hypercholesterolemia. It was shown that nonspecific endocytosis was activated 1,6 times as compared to control and in some areas of endothelium up to 5-6 times at early stages of experimental hypercholesterolemia.

[Ultrastructural characteristics of collagen formation by the smooth muscle cells of the aorta in rabbits with experimental atherosclerosis]. / Ul'trastruktural'nye osobennosti obrazovaniia kollagena gladkomyshechnymi kletkami aorty pri eksperimental'nom ateroskleroze u krolikov.

The development of experimental atherosclerosis in rabbits is accompanied by infiltration into the aorta intima of low density lipoproteins and marked proliferation of smooth muscle cells. The activated smooth muscle cells take part in desmoplastic reactions being the main source of collagen synthesized in atherosclerotic plaques. Outgrowth of the connective tissue in the zone of the elastic membrane fenestration leads to disturbance of the outflow of plasma components and causes edema of the intima. It is assumed that an atherosclerotically altered vascular wall may synthesize collagen with abnormal antigenic structure acquiring autoantigenic properties.

[DNA synthesis in the foam cells of the vascular wall in experimental atherosclerosis in rabbits]. / Sintez DNK v penistykh kletkakh sosudistoi stenki pri éksperimental'nom ateroskleroze u krolikov.

Proliferative activity of the aortic intima cells in the course of experimental rabbit hypercholesterolemia is studied. The most intensive DNA synthesis was found in macrophages and smooth cells transforming into the foam cells as shown by electron-microscopic radioautographic analysis. DNA synthesis by damaged and dying foam cells is shown. Cytophotometric analysis showed the small proportion of foam cells in the atherosclerotic lesions to be polyploid.

[Role of monocytes-macrophages in atherogenesis]. / Rol' monotsitov-makrofagov v aterogeneze.

The study of the coronary arteries atherogenesis with the use of scanning and transmission electron microscopy was performed on the material of emergency necropsies of 45 patients who suffered the primary cardiovascular pathology. The transformation of macrophages into the foamy cells were studied in vitro with the use of peritoneal mouse macrophages and modified LDL labelled with colloidal gold as well as a method of phase-contrast cinemicrography. Two types of macrophages were distinguished ultrastructurally: scavenger-macrophages participating in the phagocytosis of lipoproteins and transforming into the foamy cells and secreting macrophages determining vascular wall homeostasis and ensuring the T-lymphocyte inclusion into the immune reactions and the contact with target cells. Balanced cell kinetics and cytokine secretion at early stages of atherosclerosis determine whether the lipid spot would regress or would transform into the atherosclerotic plaque.

[Intercellular contacts in portions of early atherosclerotic lesions of the human aorta]. / Mezhkletochnye kontakty v uchastkakh rannego ateroskleroticheskogo porazheniia aorty cheloveka.

The ultrastructure of human thoracic aortas collected at autopsy from 16 trauma victims aged from 3 to 40 years was investigated. Intercellular contacts were found in all aortas examined. The contacting cells localized predominantly in aortic areas predisposed to atherosclerosis, i. e. in areas situated around the ostia of the intercostal arteries. Most of contacting cells were monocytes--macrophages (Mn/Mph) which interacted with foam cell and intimal smooth muscle cells (SMCs). Only occasional contacts were formed by lymphocytes and endothelial cells. All intimal contacting SMCs were of the synthetic phenotype, i. e. they did not contain myofilaments and had well developed endoplasmic reticulum and Golgi apparatus. In thickened aortic intima the contacting cells were seen with the signs of destruction. The data obtained suggest that the contacts between intimal cells may be the consequence of the immune reaction directed to the transfer of information, cell cytolysis and utilization of cell debris.

[Beta-lipoprotein transport via the endothelium in experimental hypercholesterolemia (an electron microscopic and autoradiographic study)]. / Transport beta-lipoproteidov cherez éndotelii pri éksperimental'noi giperkholesterinemii (élektronno-radioavtograficheskoe issledovanie).

The paper analyses mechanisms and routes of transport of low density beta-lipoproteins (LD-beta-LP) into the vessel wall via the endothelial barrier in experimental hypercholesterinemia. The use of electron microscopic autoradiography with 125I-labeled LD-beta-LP allowed the subtle initiating mechanisms of the development of atherosclerotic lesions of arteries to be analysed. Electron microscopic studies confirmed the concept that beta-LP in atherosclerosis penetrate into the vessel wall as an intact particle. At different stages of formation of atherosclerotic changes of arteries the ways of transport of LD-beta-LP into the intima of arteries were shown to vary. Qualitative and quantitative rearrangements within the endothelial barrier indicate great variability of the ways of transport of high molecular components of plasma into the vessel wall.

[Phenotypic variants of the smooth-muscle cells in an atheromatous plaque of the human aorta]. / Fenotipicheskie varianty gladkomyshechnykh kletok v ateromatoznoi bliashke aorty cheloveka.

The authors investigated the expression of cytoskeletal proteins and the ultrastructure of cells in normal intima and atheromatous plaque of human aorta. It has been established, using double immunofluorescent method and a set of antibodies that intimal smooth muscle cells /SMC/ of normal aorta express myosin, vimentin, alpha-actin and actin but not desmin. In seven out of 28 atherosclerotic plaques the cells contained desmin and all other SMC cytoskeletal proteins were found. These cells had the ultrastructural features of SMC, i.e. well-developed endoplasmic reticulum and Golgi apparatus. Besides, some cells in 13 atherosclerotic plaques proved to be myosin-, alpha-actin- and desmin-negative. The cells were stained with monoclonal antibodies specific to SMC but not with macrophage-specific antibody. Ultrastructurally, the cytoplasm of the cells was filled with rough endoplasmic reticulum and a developed Golgi complex, but a certain portion of the cells retained basal lamina and myofilament bundles. The peculiarities of cytoskeletal protein in expression and ultrastructure of cells in human aortic atherosclerotic plaques may be explained by a phenotypic modulation of vascular SMC.

[Monocyte-macrophage infiltration in portions of atherosclerotic lesions of the human aorta]. / Monotsitarno-makrofagal'naia infil'tratsiia v uchastkakh rannikh ateroskleroticheskikh porazhenii aorty cheloveka.

Human thoracic aorta was taken from trauma victims aged from 6 to 40 years. Cell composition of the intimal layer was investigated in the lesion predisposed (LP) areas of the aorta and in the lesion resistant (LR) areas. By double immunofluorescent staining with mono and polyclonal antibodies to monocytes/macrophages (Mn/Mph) and smooth muscle cells (SMC) the presence of Mn/Mph was revealed in all aortas studied. The number of these cells was 2-6 fold higher in LP areas, compared to LR areas in all persons over 21 years of age. Scanning electron microscopy revealed Mn on the luminal surface of the vessel the number of which was frequently higher in LP areas. Mn/Mph in LP areas were heterogeneous in their structure depending on the depth of their localization in the intima. The revealed Mn/Mph infiltration in aortas of young subjects may be the earliest manifestation of the atherosclerotic lesion.

[The pharmacological characteristics, immunochemical identification and study of the location of quisqualate receptors in the rat and human brains]. / Farmakologicheskaia kharakteristika, immunokhimicheskaia identifikatsiia i issledovanie lokalizatsii kviskvalatnykh retseptorov golovnogo mozga krysy i cheloveka.

The kinetics of [3H]-L-glutamate binding to brain synaptic membranes (SM) and to glutamate-binding proteins (GBP) was determined with agonist and monoclonal antibodies (MAbs). It was revealed, that rat and human brain GBP have individual protein components with M(r) from 14 to 92 kDa. Quisqualate inhibited [3H]-L-glutamate binding to solubilized and to purified 68 kDa protein component. MAbs have the most activity, and NMDA was failure. It has been shown that 68 kDa component antigen determinants are similar to those of bovine, frog and rat brain synaptic membranes. Anti-GBP monoclonal antibodies blocked functional non-NMDA receptors in isolated frog spinal cord. Immunocytochemistry was done on rat and human brain sections. Distribution of quisqualate receptors was determined with light and electron microscopy. Some properties of vertebrate CNS non-NMDA receptors are discussed.