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Biomedical subjects

L N Mikhaĭlova

Publications and source records attributed to L N Mikhaĭlova.

At least 19 recordsLinked to original sources
PubMed1986

[Development and differentiation of bone marrow mechanocytes].

Morphological studies in the model with the complete destruction of bone marrow in the diaphysis of the tubular bone have revealed the process of stromal elements regeneration. Within the first 24 hours after the trauma insignificant accumulations of fibroblast-like cells in the lumen of some vascular channels have been observed in cell-free cortical plates. In two days spheric cells with a large dense nucleus were detected in tissue-free bone-marrow diaphysis cavity. This fact seems indicative of the viability of the vascular channel cells. This was manifested in the regained tinctorial and biological properties (i.e. the ability to proliferate). The recovery of these properties are likely to be related to vessel pericytes in the microcirculatory net of the vascular channels.

Animals↗
PubMed1986

[Osteogenic precursor cells in repair osteogenesis].

Histological and electron-microscopic radioautographic investigations of regenerating medullar tissue were performed in rabbits following curettage. Low differentiated connective tissue cells were shown to possess the highest proliferative activity. DNA synthesis mainly took place in low differentiated, endothelial and osteogenic cells. It is suggested that low differentiated cells take part in histogenesis of regenerating medullar tissue, including osteo- and angiogenesis.

Animals↗
PubMed1985

[Histogenesis of skeletogenic tissue in bone regeneration during distraction].

Light and electron microscopy were employed to study the histogenesis of the skeletogenous tissue during stable distraction osteosynthesis according to G. A. Ilizarov. Osteosynthesis proceeded on the basis of the invariably existing fibrillar connective tissue growth plate situated in the medium part of the distraction regenerate. Osteogenesis was continuously accompanied by angiogenesis. Preservation of the connective tissue plate is accounted for by the stimulating influence of distraction on fibrillogenesis. The authors suggest the common character of the histogenesis of the vascular and bone tissues in the connective tissue blastema of the interfragmental distraction regenerate.

Animals↗
PubMed1983

[Electron microscope study of pigmented villonodular synovitis].

The ultrastructure of pigmented villonodular synovitis was studied on the operation material from 5 patients. Differences in the cell composition of villous and nodular formations typical of the disease were found. Different functional conditions of foamy cells was noted. Since foamy and fibroblastic cells were most numerous the possibility of accumulation of mononuclear phagocytes capable of excreting a proliferation factor in response to the primary local disturbance of lipid metabolism in fibroblast cells in pigmented villonodular synovitis is discussed.

Adolescent↗
PubMed1981

[Electron microscopic study of reparative osteogenesis following electric stimulation of bony tissue regeneration].

Electron microscopy was used to study the regenerating bone tissue in experimental resection of the diaphysis fragment of the rabbit radius under osteogenesis stimulation by means of pulsed low-frequency electric current. Proliferation and differentiation of fibroblasts and osteoblasts of the bone regenerating tissue were more active under electric stimulation. Hypertrophy and hyperplasia of cell organelles occurred earlier as compared with control. Cell secretion was found to be intensified, manifesting by output of greater amounts of collagen protein. As a result of changes listed, the newly formed bone tissue rapidly filled the defect between the fragments.

Animals↗
PubMed1979

[Electron microscopic study of the characteristics of skeletogenic tissue differentiation during distraction osteosynthesis].

Electron microscopic examination of the regenerating tissue was performed after distractional osteosynthesis carried out by the method of G. A. Ilizarov. The results showed osteogenesis to occur on the basis of the fibrous tissue formed in diastasis. The observed zones of the regeneration typical of distractional osteosynthesis are due to functional stimulation (tension) resulting in the arrangement of collagen fiber bundles and bone trabeculae in the direction of the extension forces. Cells of the skeletogenic tissue, between the bone fragments are also arranged with their longitudinal axis along the collagen fibril bundles. The ultrastructural pattern of the osteogenesis after distractional osteosynthesis reflects the intensification of the synthesis of glycosaminoglycan-protein complexes forming the main substance of the bone tissue.

Animals↗
PubMed1978

[Characteristics of bone regeneration in distraction of bone fragments].

One of the features of distraction osteosynthesis consists in the presence of a zone of permanent growth between bone breaks. Electron microscopic examinations of the permanent growth zone at 14 and 21 days of distraction showed the presence in the zone of cells of three kinds: fibroblast-like cells, osteoblastic elements and little-differentiated preosteoblasts. Fibroblast-like cells and osteoblastic elements were found to have ultrastructural changes of the endoplasmic reticulum indicating the occurrence of intensive synthesizing processes. Specific conditions of blood supply cause hypoxic metabolism with typical enhanced formation of fibrillae which leads to the preservation of the fibrillar tissue throughout the entire period of distraction. The fibrillar tissue in diastace may be considered to be a special growth plate.

Animals↗
PubMed1975

[Electron autoradiographic study of the synthesis of RNA in the reparative regeneration of bones].

The metabolism of RNA in cells of callus 4 and 7 days following the fracture was studied. At the three stages of differentiation of osteogenic cells--preosteoblasts, differentiating osteoblasts, and osteoblasts--there was noted a similar dynamics of synthesis and transfer of RNA. One and a half hour after administration of a precursor of RNA--uridine-5H3 grains of silver concentrated predominantly above the nuclei, nucleoli being marked most intensively. Four hours after the administration of the precursor the total number of grains above the cells increased, mostly above the granular endoplasmatic reticulum; density of grains over the nuclei at this time did not change significantly, whereas that over the nucleoli decreased notably. The relationship between the observed features of the RNA metabolism and various stages of differentiation of osteogenic cells is considered.

Animals↗
PubMedDate not supplied

[The histo- and ultrastructural characteristics of the bone tissue in osteogenesis imperfecta].

Histo- and ultrastructure of bone tissue in 28 persons (2 section observations and 26 cases of bone biopsy analysis) with congenital fragility of the bones and dysosteogenesis were studied. Age of the victims ranged from 6 months to 38 years (20 men and 8 women). Against the background of bone rarefaction and decrease in quality of basic bone substance the quantity of osteocytes for a unit of osseous beam area increases. Electron-microscopic investigation revealed changes in osteoblast structure (3 types detected) by the degree of development of granular endoplasmic reticulum. In the 2nd and 3d type of osteoblasts the decrease in the quantity of elements of granular endoplasmic reticulum was noted which may be connected with disturbance of biosynthetic processes in cell and fibrillogenesis with maturation of collagenous fibrils and their mineralization. Histo- and ultrastructure of the bone in dysosteogenesis are rather typical and in total with clinico-roentgenological data are informative enough for making diagnosis.

Adolescent↗