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N V Rodionova

Publications and source records attributed to N V Rodionova.

18 recordsLinked to original sources
PubMed1988

[Osteoblasts during various functional states].

At the electron microscopical investigation of osteoblasts in different zones of osteogenesis (enchondral foci, metaphyses, endosteum) in the rat and rabbit femoral bone it has been revealed that their population is heteromorphic. As demonstrate cytochemical data and radioautography, using 3H-uridine, 3H-glycine, 35S-sulfate, 45Ca, results of measurements in osteoblast population, 4 morpho-functional states (or types) are defined. In areas of an intensive osteoplastic process there are young osteoblasts (I type), mature functionally active osteoblasts (II type), osteoblasts with a hypertrophic endoplasmic network (cell-depots of the secrete--III type). In preosteoblasts and osteoblasts of the I type a higher than in osteoblasts of other types intensity of 35S-sulfate incorporation and alkaline phosphatase activity is revealed. In osteoblasts of the II type processes of biosynthesis of collagenous proteins predominate. Osteoblasts of the III type are subjected to destruction during secretion process. In the areas where osteopoesis is dying away, osteoblasts of the I and II types transform into a poorly active state, concerning specific biosynthesis (osteoblasts of the IV type). Presence of osteoblasts having various functional states in the areas of intensive osteopoiesis, depends on certain asynchronity of specific processes of biosyntheses, that occur in them. The morpho-functional states described are regarded as a specific peculiarity in function of collagene-producing cells.

Alkaline Phosphatase↗
PubMed1986

[Stromal cells of the bone marrow in growing bone].

By means of electron microscopy, cytochemistry and radioautography with 3H-thymidine, the bone marrow stromal cells have been studied in the zones of endochondral osteogenesis in the rabbit and rat femoral bones. In the stromal cells demonstrating a high alkaline phosphatase activity are distinguished: perivascular, reticular fibroblastic, osteogenic cells. Populations of the perivascular phosphatase-positive cells include poorly differentiated DNA-synthesizing forms, as well as cells with signs of differentiation into stromal fibroblasts. Cleft-like spaces in cytoplasm of the fibroblastic reticular cells are, probably, formed as a result of lymphocyte-like mononuclears passing through. Phagocyting stromal elements are presented by macrophages, having perivascular localization and including into composition of erythroblastic islets. Mononuclear macrophages are revealed also on the surface of osseous trabecules, where they participate in destruction of hemopoetic and osteogenic cells.

Alkaline Phosphatase↗
PubMed1986

[Chondroclastic properties of the cartilaginous tissue macrophages of developing bone].

By the electron microscopic and cytochemical studies, in the vascular canals of cartilaginous epiphyses and in the zones of endochondral process of the rabbit and rat femoral bones, there were revealed monocytes, macrophages, the cells of the intermediate differentiation stages among the perivascularly located forms. In the lysosomes as well as on the surface of cytoplasmic membrane of mature macrophages the activity of acid phosphatase and non-specific esterase was demonstrable. Phagolysosomes showed accumulation of 35S-sulphate label 2 hours after its injection into an organism. Macrophages cause degradation of non-mineralized cartilaginous matrix by secreting hydrolases and other enzymes and then phagocytize the preformed substrate. In the zones of endochondral process, macrophages also penetrate into the "capsules" of hypertrophic chondrocytes and are involved in their destruction. The cells are regarded as tissue--specific macrophages--chondroclasts.

Absorption↗
PubMed1985

[Dynamics and ultrastructural characteristics of osteoclast formation].

Using electron microscopy and 3H-thymidine autoradiography it has been shown that osteoclasts of rats and rabbits are formed by fusion of cell precursors which become members of the osteoclasts 14 hours following S-phase. Monoblasts and promonocytes are considered as DNA-synthesizing forms. A single injection of parathormone in a dose of 10 units/100 g of body weight leads to an increase in the fractions of DNA-synthesizing cells. Monocytes and macrophages appear to be direct osteoclast precursors in resorption zones. As a result of their fusion there appear "unfixed" polynuclear macrophages (young osteoclasts). The number of osteoclast nuclei increases also at the expense of little-differentiated phagocytes, the inclusion of the latter takes place at different stages of the life span of osteoclasts depending on the intensity of bone resorption processes. The structural characteristics of fusion of cell precursors are considered.

Animals↗
PubMed1983

[Ultrastructural characteristics of osteoclasts in different functional states].

By electron microscopy and autoradiography, a study was made of osteoclasts in the metaphyseal zones of the femora of 1-7-day old rabbits and rats. It was established that depending on the intensity of resorptive processes osteoclasts noticeably differed in their morphology (shape, size, number of nuclei, degree of development of intracellular organelles, "brush border"), as well as in the level of biosynthetic activity registered by incorporation intensity of 3H-uridine and 3H-methionine in these. According to these indices, osteoclasts were classified as young, mature functionally active, and non-active osteoclasts, as well as perishing ones. The defined morpho-functional states represent successive stages of the life cycle of osteoclasts.

Animals↗
PubMed1982

[Perivascular and osteogenic cells in periosteal ontogenesis].

The structure of the perivascular cells, their interrelations with the vascular wall and differentiating osteoblasts has been studied in the white rat and rabbit fetuses and newborns during periosteal osteogenesis by means of electron microscopic radioautography using 3H-thymidine. The blood bed in the perichondrium in the zones, where osteogenesis is developing, has a capillary-sinusoid type of structure. Among the perivascular cells, poorly differentiated cells, adjoining the endothelium and intensively incorporating 3H-thymidine, are revealed, as well as the cells that are territorially isolating from the endothelium and demonstrating certain signs of their differentiation into the osteogenic ones. This supports the previously obtained data on historadioautography with 3H-thymidine that during the periosteal osteogenesis a successive differentiation of the perivascular cells (via the periosteoblast stage) into osteoblasts takes place. The process is accompanied by a decreased proliferative cell activity, at the expense of a prolonged time of generation and a progressive yield of cells out of the mitotic cycle. The poorly differentiated perivascular cells are considered as induceable ones, and the preosteoblasts--as the determined osteogenic precursor-cells. The cells growing into the perichondrium with capillaries, when the periosteal ontogenesis develops, represent a peculiar population of cells with polypotent properties, which participate in genesis of osteoblasts and periocytes.

Animals↗
PubMedDate not supplied

[Reproduction and differentiation of the cells in enchondral osteogenesis].

Light and electron-microscopical 3H-thymidine autoradiography was used to study the dynamics of cell populations in the zones of enchondral osteogenesis in a tubular bone. In the early postnatal ontogenesis little differentiated perivascular cells are characterized by the highest proliferative activity in this region; they are considered as a population containing initial forms of the histogenetic sequence (differon) of the stromal fibroblast-like cells including osteoblasts. Differentiation of osteogenic cells from the initial forms to the mature osteoblasts proceeds through a number of successive divisions (1-3 divisions) and is accompanied by a decrease in the proliferative activity due to the increase in the generation time and decrease in the cell proliferative pool. The major part of osteoblasts is outside the mitotic cycle. At the later stages of ontogenesis the intensity of growth processes in the bone is provided for by changes in the proliferative pool of the committed precursor cells (preosteoblasts) which make a part of endosteum, vascular channels and bone marrow stroma.

Animals↗
PubMedDate not supplied

[Submicroscopic changes in the capillary cells of an area of osteogenesis during body uptake of lead acetate].

Ultrastructurometry has revealed that daily entry of lead acetate in a dose of 50-100 mg/kg per body weight for 1-2.5 months increases chromatin condensation in nuclei, promotes swelling and myelin-like degeneration of the mitochondria, hyperplasia of the endoplasmic net, as well as appearance of the "enlightment" zones in the cytoplasm of endotheliocytes and perivascular cells of the capillaries from a metaphyseal zone of the rat femur. These changes are a consequent of the edema of cells and of the decrease in their biosynthetic activity.

Animals↗
PubMedDate not supplied

[Glycosaminoglycan metabolic disorders in periosteal and endosteal osteogenic cells in phenol poisoning].

The analysis of 35S sulphate incorporation into the growing bone structures in the experiment with 2-3 week guinea pigs subjected to long-term phenol intoxication made it possible to conclude that 35S sulphate assimilation by the osteogenic cells of periost and endost is less intensive in the treated animals, particularly in those receiving a large dose of phenol, (40 mg/kg) than in the control ones. This testifies to the reduction of the biosynthesis rates of sulphated glycosaminoglycans in the bone growth regions.

Animals↗
PubMedDate not supplied

[Structural identity of the multinuclear chondro- and osteoclasts in developing bone].

Distributional peculiarities and the ultrastructure of multinuclear elastic cells have been studied in the developed thighbone of rat and rabbit fetuses and new-borns. Multinuclear chondro- and osteoclasts exhibit no noticeable structural specificity with respect to the resorption substrate and are considered to be one and the same type of clastic cells whose main function is to resorb the mineralized tissue.

Animals↗
PubMedDate not supplied

[Ultrastructure of DNA-synthesizing cells in an enchondral focus and osteogenic precursor cells].

It was shown by light and electron 3H-thymidine autoradiography that in the zones of endochondral osteogenesis in a tubular bone the little-differentiated perivascular cells are characterized by the most intensive proliferation among the DNA-synthesizing cells of the stroma. A comparison of the ultrastructural features and the distribution of labelled cells, their topographic interrelations at different times following the isotope injection suggests that during histogenesis in the endochondral centres the little-differentiated perivascular cells become spatially separated and are involved in the formation of the stromal cellular elements (in particular, fibroblasts, reticular cells, osteoblasts). In the developing and mature stroma, as well as in the endost, the little-differentiated forms of the population are preserved; the number of DNA-synthesizing cells among them decreases with age. It is suggested that the population includes stromal stem cells.

Aging↗
PubMedDate not supplied

Features of the reproduction of epiphyseal cartilage perivascular cells according to the results of an autoradiographic study.

In the system of a vascular-cellular complex of cartilage epiphyses the perivascular cells exhibited the highest proliferative activity, as revealed by autoradiography with labelled DNA precursor (3H-thymidine). The constant loss of cells after division in this population is probably associated with their differentiation and transition into another state. This phenomenon is strongly pronounced at the centre of enhondral ossification, and perivascular cells could be considered as one of possible sources of histogenesis developed in cartilage epiphyses.

Animals↗
PubMedDate not supplied

[Ultrastructure of the ductal epithelium in the human pancreas in chronic pancreatitis].

Three different kinds of cells are distinguished within the epithelium of the pancreas ducts in patients with chronic pancreatitis: main ductal cells among which there are "light" and "dark" forms differing from each other in the level of their biosynthetic apparatus development and being in the state of different functional activity; endocrine cells with morphological features of chromaffin-like and D-cells of the gastrointestinal tact; migrating cells (histocytes, granulocytes, lymphocytes). Characteristic features of destruction in the pathologically altered epithelium are described.

Chronic Disease↗