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Biomedical subjects

L K Romanova

Publications and source records attributed to L K Romanova.

At least 37 records · Page 2Linked to original sources
PubMed1982

[Response of pulmonary surfactant and air-blood barrier to general acute hypothermia].

Male rats weighing 235-350 g were subjected to cooling for 4-6 hours at -20 degrees C. The lungs of the supercooled animals developed interstitial and intraalveolar edema, focal atelectases and local hemorrhages. It was shown that under overall acute hypothermia the following processes occur in the lungs: 1/local impairment of the air-blood barrier integrity due to hydropic dystrophy and degeneration of type I alveolocytes and endotheliocytes; 2/disintegration, aggregation and membrane lysis of the alveolar surfactant which underlie atelectases; 3/accumulation of the surface active material in the interstice of the interalveolar septa both because of elimination of disintegrated surfactant by type I alveolocytes and as a result of phospholipid secretion from the basal side of type II alveolocytes; 4/an increase in functional activity of type II alveolocytes and alveolar macrophages.

Animals↗
PubMed1980

[Effect of colchicine on secretion of alveolar surfactant in intact and regenerating rat lungs].

Electron microscopy showed that colchicin in a total dose of 0.6 mg/100 g body weight of noninbred male white rats inhibited alveolar surfactant secretion into the alveolar lumen in both intact and regenerating lungs. This was associated with a partial or complete alveolar collapse. In the course of inhibition of surfactant secretion, on the apical surface of type II alveolocytes there was an activation of surfactant secretion by way of exocytosis into the interstitial space in the basal part of the cells. Disintegration of the collagenous and elastic fibers as well as disturbance of the membranes occurred in the areas where the material of lipid character and products of its metabolism appeared. A hypothesis is suggested about the possible role of such a disturbance in the character and level of alveolar surfactant secretion in the development of lung abnormality under the effect of the factors inactivating the cytoplasmatic micro tubules.

Animals↗
PubMed1979

[Ultrastructural organization of the brush alveocytes of normal and hypertrophic rat lungs].

In non-inbred male rats, 140-200 g of body weight, the left lung was removed. In the right lung of the experimental and intact animals, brush alveolocytes were revealed electron microscopically and their structural organization was stated 1, 3, 7, 30 and 274 days after the operation. It was stated that during the process of compensatory hypertrophy in the lung, the occurrence rate of these cells increased considerably. In controls only 3 such cells were revealed, while in the experiment, the number of the brush alveolocytes was 20. In the experiment, most of the cells had signs of hyperfunction: increased amount of pinocytic vesicles in the apical part of the cell, dilated canaliculi in granular cytoplasmic network, formation of "laminar" structures from the membranes of the canaliculi of the granular cytoplasmic network. The brush alveolocytes were especially active during the period of acute alveolar hypertrophy (5-7 days after the operation) and correlated with the state of alveolar surfactant. The data obtained supported the hypothesis on chemoreceptor nature of the cells in question and demonstrated their participation in regulation of alveolar surface tension.

Animals↗
PubMed1979

[Polyfunctional role of the alveolar brush cells in the rat lung].

By means of scanning and transmission electron microscopy it was demonstrated that the number of vacuoles located in the apical part of cytoplasm in alveolar brush cells of the regenerating rat lung increases, hyperplasia of Golgi-complex takes place and the activation of the protein-synthetising apparatus is evident. The immature surfactant material (osmiophilic lamellar bodies) and secretory dense core vesicles were found in the cytoplasm of alveolar brush cells. Intramuscular injections of colchicin to rats (0.1 mg/100 g body weight) 6 times during 24 hours before decapitation does not influence the number, topography and structure of microfibrilla bundles contained in a sufficient amount by alveolar brush cells. At the same time a part of microvilli of alveolar brush cells undergoes destruction and resorption under the action of colchicin. The data on ultrastructural organization of alveolar brush cells show that they are able to fulfill several functions: absorptive, contractile and secretory.

Absorption↗
PubMed1978

[Kinetics of cell proliferation in regenerating rat liver following subtotal resection].

Partial (78--80%) hepatectomy was conducted in male rats. The maximal mitotic activity of hepatocytes was seen 38--48 hours after the operation. It was found with thymidine-3H (pulse label) that the G2 period lasted 6 hours and the minimal duration of the S-period was 6 hours. During the liver regeneration after its subtotal resection there was asynchronization of the hepatocyte entrance into the S-period and mitosis, and cell retardation in the G1-and G2-periods. The mentioned changes in the hepatocyte proliferation are the results of intracellular metabolism disturbance under conditions of an excessive functional requirement.

Animals↗
PubMed1975

[A factor influencing the process of chromatin condensation in hepatocytes of regenerating rat liver].

It was shown with the model supramolecular chromatin systems that the activity of the factor of chromatin condensation changes in the process of liver regeneration. No activity of the factor of chromatin condensation was found 20 hrs after operation. Within 32-33 hrs (in the period of increased mitotic frequency) its activity approaches that prior to the operation. The nature of the activity of the factor of chromatin condensation is discussed with respect to the functional state of chromatin.

Animals↗
PubMed1975

[The state of the "glycocalyx" of rat lung cells following left-sided pneumonectomy].

Edema in the tissue of the right lung developed 24 hours after the leftsided pneumonectomy. It was found that: 1) the layer of acid mucopolysaccharide on the surface of the alveolar and endothelial cells became thicker; 2) accumulation of the product of reaction with the RR on the surface of the alveolar cells of type 1 and of the endothelial cells took place; 3) "blisters" coated with the product of reaction with the RR (Red Ruthenium) appeared. These "blisters" were connected with the plasmolemma of the alveolar and endothelial cells. All these findings suggest that acid mucopolysaccharides of the lung surfactant system participated in the accumulation and elimination of the water from the tissues of the air-blood barrier.

Animals↗
PubMedDate not supplied

[Cytophysiology of lung bronchiolar secretory cells--source of inflammation "antimediators"].

Literature and original authors' data on topography, structural organization and function of secretory bronchiolar Clara cells of the lungs in various representatives of mammals and humans are analyzed. Involvement of Clara cells in bronchiolar clearance, metabolization of xenobiotics and carcinogenic substances, synthesis of specific low molecular proteins (SLP), antimediators of inflammation. Special attention is drawn to the SLP properties; proteins with antiprotease properties are revealed among SLP. Other proteins are modulators of local inflammatory resection in the lungs or regulators of pulmonary surfactant function.

Animals↗
PubMedDate not supplied

[Present views of prenatal morphogenesis of human lung].

Published and original data on human lung morphogenesis during prenatal development are reviewed. Morphofunctional description of the lung at various phases of prenatal morphogenesis is given. Differentiation of various lung structures, surfactant system, development of intrapulmonary fluid, and the onset of breathing movements of the fetus are considered in chronological order. The "critical periods" when the fetal respiratory organs are most sensitive to unfavorable factors are considered. Morphofunctional tests for lung maturity are described applicable for predicting lung pathology of human fetus.

Bronchoalveolar Lavage Fluid↗