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Biomedical subjects

V F Ivanova

Publications and source records attributed to V F Ivanova.

At least 55 records · Page 3Linked to original sources
PubMed1975

[Embryonic and post-embryonic development of the parietal and visceral peritoneum in white mice].

Light and electron microscopy were used in order to investigate histogenesis of the parietal and visceral peritoneum of white mice in embryonic and postembryonic periods of development. Four periods were distinguished, during which gradual differentiation of the primordium material into tissue structures (mesothelium and the connective tissue) of the peritoneum were observed. Asynchronous differentiation of the mesothelium as well as certain correlation in the degree of differentiation of mesothelial and mesenchymal cells took place at all stages of the embryonic and postembryonic development. More differentiated cells of prolonged shape were predominant in the mesenchyma even at early stages (11 days) in those portions where the lining of the secondary cavity of the body resembled mesothelim in its structure.

Animals↗
PubMedDate not supplied

[The structure and cytophysiology of the endocrinocytes of the gastric epithelium in a disordered food regimen].

By means of the light and electron microscopic methods the differentiation and the genesis of the epithelium endocrinocytes of the stomach mucous membrane were studied in the albino rats, fasted for 72-144 hours. The deprivation of food is followed by the increase of the number of endocrinocytes and by the change of their ultrastructure. The latter demonstrates the delay of the elimination of the secretory material in some cells (ECL, G, D, D1 cells) while the active functional condition was found in the others (ECL, A-like cells). Exo-endocrine cells with the EC or A-type granules are found in the epithelium, which is regarded as a mechanism aimed at the increase of the number of the appropriate (ECL or A-type of endocrinocytes, participating in the general metabolism of the organism.

Animals↗
PubMedDate not supplied

[The ultrastructure of the pancreatic endocrinocytes of human fetuses in postmortem autolysis].

The method of electron microscopy was used to study the morpho-functional state of pancreatic islands of human fetuses at different terms (10-54 h) after clinical death. Within the periods of time in question the island secretory cells preserve the structure characteristic of each type (B, A, D). The development of symptoms of postmortem autolysis of the pancreatic island is not a chaotic fleeting physico-chemical reaction and is characterized by a definite sequence of cytological changes of endocrinocytes. A conclusion is made that cadaveric material of the pancreas is good for preparing the pancreatic island culture for using it in the following tissue substituting therapy of patients with diabetes mellitus.

Autolysis↗
PubMedDate not supplied

[Features of expression of the pertussis toxin operon under the control of its own and heterologous promotors in Bordetella bronchiseptica cells].

Expression of the cloned operon encoding the pertussis toxin synthesis under the control of operons own vir-dependent promoter or vir-independent promoter of Escherichia coli origin was studied. Proteins produced by the recombinant strains have been characterized. The pertussis toxin operon was shown to express under the control of both homologous and heterologous promoters in Bordetella bronchiseptica cells. Use of the lac-promoter increases the yield of produced toxin twofold. Copy number of operon in the cell does not influence the level of toxin production. The synthesized protein can be transported into the culture medium. The biological and physico-chemical properties of the protein are similar to the ones of the natural pertussis toxin. Bordetella bronchiseptica strain producing the toxin with decreased toxic activity has been obtained. Thus, a simple system for cellular expression of the toxin operon was constructed in Bordetella bronchiseptica. It permits one to construct new strains producing nontoxic derivatives of the pertussis toxin for construction of nonreactogenic vaccines.

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