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Biomedical subjects

A B Shekhter

Publications and source records attributed to A B Shekhter.

At least 73 records · Page 4Linked to original sources
PubMed1977

[Successes in the control of childhood droplet infections in the UkrSSR during the 60 years of Soviet government].

Marked achievements in reduction of morbidity and mortality from the main child infections were reached as a result of radical social changes during the years of Soviet power improvement of welfare of the population, science development, proper organization of antiepidemic measures, creation of effective prophylactic preparations and mass immunization. Poliomyelitis is practically wiped out in the Republic, diphtheria incidence fell sharply and whooping cough and measles incidence decreased considerably.

Adolescent↗
PubMed1977

[Macrophage-fibroblast interaction and its possible role in regulating collagen metabolism during wound healing].

The role of macrophages in the resorption of denatured collagen in the wound tissue was demonstrated by transmission and scanning electron microscopy investigation. Tight cell contacts between the macrophages and fibroblasts in the granulation tissue preceded active collagen synthesis and fibrillogenesis. A hypothesis was suggested according to which these contacts played an important role in the transfer of specific signals for the initiation of collagen biosynthesis; collagen decomposition products were considered as the actual signals, thus connecting the collagen catabolism and biosynthesis. Such a feed-back mechanism probably served as an integral part of the general hemostasis regulating the growth of connective tissue.

Animals↗
PubMed1977

[Wound healing as an autoregulatory process].

A hypothesis of autoregulation of the reparative growth of the connective tissue based on the inverse relationship between degradation and collagen biosynthesis is suggested. At the ultrastructural level such homeostatic mechanism is realized in two stages: (1) resorption by macrophages of collagenic fibrillae of the tissue necrotized as a result of trauma and inflammation, induction of collagen genesis by cell contacts between macrophages and fibroblasts, enhanced fibrillogenesis; (2) the inhibiting effect of collagen fibers of a mature tissue contacting with fibroblasts on collagen biosynthesis with simultaneous induction of fibroclasia.

Animals↗
PubMed1976

[Possibilities of studying 3-dimensional structure of the arterial wall with help of scanning electron microscope].

A complex of methods for investigation of the architectonics of the vascular wall is suggested. It was established that an elastin carcass of all the layers of the arterial wall was formed of laminar membranes consisting of cylindrical elastic fibers with a diameter 1.5--3 mcm having a fibrillar structure. The window-like structure of the laminas was due to separation of bibers. In the laminar membranes of the intima and media, including internal ones, elastic fibers had circular, and in adventitia--longitudinal distribution, which ensured radial and longitudinal elasticity of the wall of arteries. Smooth muscle cells, that had spiral orientation, were attached with their ends to the adjacent membranes thus regulating their tonus. They are surrounded with elastic and collagenous fibrillas, which cover also membranes and connect all the layers of the wall of arteries into one morpho-functional system with a high structural stability and plasticity.

Arteries↗
PubMed1975

[Fibroblast-fibroclast: The ultrastructural mechanisms of resorption of collagen fibers in involution of the connective tissue].

Using various experimental models (postpartum involution of the uterus, resolution of a subcutaneous scar which replaced the collagen implant and connective-tissue capsule following the removal of a foreign body) and electron-microscopy and histochemical methods of investigation intra- and extracellular resorption of th e collagenous fibres was extablished. The main role in this process was played by fibroblasts which uncer these conditions could funciton as fibroclasts phagocyting and idgesting in its cytoplasma collagenous fibrillas with the help of lysosomal enzymes. Desintegration of fibroclasts, enriching the medium with these enzymes, stimulated the extracellular lysis of the collagenous fibrillas. This lysis was particularly intensive in the presence of an inflammatory process, and even could take place before the intracellular resorption. In macrophages no intracellular lysis was observed, however, they could phagocyte denaturated collagen, deprived of structural orgainzation.

Animals↗