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Biomedical subjects

A B Shekhter

Publications and source records attributed to A B Shekhter.

At least 55 records · Page 3Linked to original sources
PubMed1986

Connective tissue as an integral system: role of cell-cell and cell-matrix interactions.

We have applied the systems approach, to the analysis of mechanisms whereby connective tissue (CT) is integrated into one functional system. The primary CT functions in health and in disease (biomechanical, trophic, protective, reparative, and morphogenetic) are carried out by means of cell-cell, cell-matrix and intertissue interactions based on feedback between these components. Both CT as a whole and its cellular and extracellular elements exhibit structural and functional heterogeneity which increases the capacity of CT for adaptation. The intercellular interactions take place via soluble and insoluble mediators, direct cellular contacts, and cell/matrix degradation products. Results of this study support the concept of internal "network" regulation of the CT composition, functions and growth through intercellular interactions at different structural levels. Feedback mechanisms between degradation and production of collagen and interactions between collagen, macrophages and fibroblasts play a special role in the self-regulation of reparative CT growth. Collagen restores an impaired self-regulation and exerts a marked therapeutic effect on wounds, burns, trophic ulcers, and other lesions. A similar function may be performed by other matrix components and degradation/secretion products of macrophages and fibroblasts.

Animals↗
PubMed1986

[Diadynamophoresis of chemical and biologically active substances in the treatment of suppurative and inflammatory diseases in diabetes mellitus].

Treatment of pyo-inflammatory diseases in patients with diabetes mellitus should be complex, individual and controlled. Obligatory total and local examinations of the organism should be performed with the involvement of cytological, histological bacteriological methods and with determination of alterations of the carbohydrate, protein, water-salt, electrolytic metabolism, acid-base state and non-specific resistance of the organism. It was shown that diadynamophoresis of proteolytic enzymes, sodium thiosulfate, potassium permanganate in the treatment of pyo-destructive diseases in 362 patients with diabetes mellitus accelerated necrolysis of tissues, shortened time of cleaning the wound and thus made the period of treatment at the hospital shorter.

Animals↗
PubMed1985

[Clinico-morphological comparisons in variants of rheumatoid arthritis (based on the data of puncture biopsy of synovial membrane)].

Altogether 564 successive puncture biopsies withdrawn from patients with different versions of RA were subjected to morphological study with the aid of a statistical analysis of the intensity of 25 signs of synovitis evaluated according to the 5-score system. The differences in the structure of synovitis were recognized: predominance of the signs of the humoral immunity (particularly plasma cell infiltration) in patients with a mild (with a favourable evolution) version of RA and predominance of the signs of the cell-mediated immunity (macrophagal and T-lymphocyte infiltration, cytolysis, proliferation and mesenchymal transformation of fibroblasts) in a grave (incurable, invalidism-producing) version. The disease of medium gravity (running a progressive course but relatively eliminated by therapy) was characterized by the combination of and undulatory time course of the signs indicated. The greatest involution of the majority of the synovitis signs as influenced by the treatment was observed in a mild, whereas the least in the grave version of RA. It is suggested that local antibody genesis may play a protective role in RA.

Adolescent↗
PubMed1985

[Features of the healing of suppurative wounds in patients undergoing treatment with collagen preparations (histochemical and electron-microscopic study)].

The dynamics of purulent wound healing developing in patients surgically treated for phlegmons or abscesses was studied histochemically and electron microscopically on the material of successive biopsies. It was shown that purulent wound healing is characterized by the desynchronization of inflammation and regeneration associated with the reduced macrophagal response and disturbances of the microcirculation system. Collagen sponge reduces inflammatory changes, activates the macrophage reaction, restores intercellular interactions, normalizes the microcirculation system, enhances proliferation and differentiation of fibroblasts, collagen synthesis and secretion, processes of fibrillogenesis, maturation of granulation tissue, epithelialization.

Abscess↗
PubMed1984

[Use of a sinusoidal current of optimal frequency to stimulate the healing of skin wounds].

Local subthreshold electrostimulation of skin wounds with sinusoidal currents at a frequency of 300 Hz which is optimal for rats (the threshold of muscle contraction is minimal) improves microcirculation, reduces inflammatory processes, stimulates proliferation and differentiation of fibroblasts and epithelium, maturation of the granulation tissue, thereby accelerating the healing of linear and large incised wounds. The increase or reduction in the optimal frequency and exposure time (for over 15 min) decrease the beneficial effect of electrostimulation.

Animals↗
PubMed1984

[Granulation tissue: inflammation and regeneration].

Healing of the external defects by the primary tension, under the scab, or by the secondary tension through the suppuration as well as the formation of granulation tissue (GT) in other organs, represent an adequate homeostatic response to the injury with stereotype kinetics of the inflammation and regeneration. The altered general and local responsiveness trophic disorders, burn and radiation trauma result in collapse of the autoregulatory mechanisms, pronounced disturbance of phagocytosis, microcirculation, mediator and contact cell interaction. This provokes the inhibition of fibroblast proliferation, depression and perversion of fibrillogenesis and the granulation tissue maturation, the formation of abnormal granulation tissue with repeated wakes of sclerosis, necrosis and inflammation, formation of persisting wounds, ulcers, hypergranulations or chronic inflammatory processes. Homeostatic protective response transforms into the pathologic response due to dissociation between the inflammation and regeneration and formation of "vicious circle".

Granulation Tissue↗
PubMed1978

[Fibroblasts and the development of the connective tissue: ultrastructural aspects of biosynthesis, fibrillogenesis and catabolism of collagen].

According to the ultrastructural features, 6 types of fibroblasts are distinguished of which two are immature forms (little-differentiated and young fibroblasts) and the rest (collagenoblasts, myofibroblasts, fibroclasts, fibrocytes) are mature cells with the functional specificity participating in the collagen production, contraction, remodeling, involution and stabilization of the connective tissue, respectively. In their turn, collagenoblasts differ from each other in the intensity of biosynthesis and the mode of collagen secretion from the cell. Fibroblasts also produce proteoglycans which are important in fibrillogenesis. Proteoglycans form cuffing around each collagen fibril as well as are components of microfibrils and floccular material which form the ultrastructural basis of the cementating substance. A system of collagen-lytic enzymes and ultrastructural signs of collagen resorption have been found in fibroblasts attesting to their role in the maintenance of equilibrium between biosynthesis and catabolism of collagen under normal and pathological conditions.

Animals↗