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Biomedical subjects

A A Birkun

Publications and source records attributed to A A Birkun.

At least 19 recordsLinked to original sources
PubMed1991

Ultrastructural changes in the endothelium of lung capillaries during experimental pneumonia.

In 35 guinea pigs a model of pneumonia was produced by transtracheal introduction of a sterile string. Electron microscopic study revealed that in the early stage of pneumonia (3-14 days after onset) endothelial cells in the capillaries of alveolar walls develop changes aimed at intensification of their function in sustaining an enhanced transcapillary gas exchange. In the following stage (1-4 months) endothelial cells develop progressing dystrophic changes leading to structural and functional disturbance of the blood-oxygen barrier. The dystrophic changes in endothelial cells develop later than those in alveolar epithelium.

Animals↗
PubMed1990

Ultrastructural changes of air-blood-barrier and surfactant in chronic non-specific lung diseases.

The study of changes of ultrastructure of air-blood-barrier components in comparison with indices of surfactant surface activity was carried out on fragments of lung tissue, cut from 36 patients with bronchiectasis, chronic abscess and fibrosis of post-pneumonic nature. Our data indicate, that in patients with chronic non-specific lung diseases the areas, more distant from the focus of affection, have changes, involving all the components of air-blood-barrier. Dystrophic and destructive processes, taking place in some pneumocytes of the 2nd type, result in suppression of the surface active characteristics of surfactant. On the other hand, processes of compensatory nature, directed to making up a deficiency of surfactant, take place.

Adolescent↗
PubMed1990

[The pulmonary surfactant status in lung immaturity].

Combined study of lungs of 85 foetuses and newborns of various gestational age and 8 newborns dying during the first month of life showed the lung surfactant (LS) system to develop in parallel with formation of respiratory parts and lung capillary network. The level of the LS surface activity increases with the increase of the duration of pregnancy and is determined by the maturation degree of the type II alveolocytes. Changes of the surface activity of the lung extract surface-active fraction in the process of lung maturation correlate with the fractional phospholipid distribution. Morphofunctional immaturity of lungs is characterized, besides histological features, by the ultrastructural immaturity of the type II alveolocytes and biochemical immaturity of LS.

Chemical Phenomena↗
PubMed1990

[Changes in surface activity of surfactant and ultrastructure of the air-blood barrier in alcoholic intoxication in experimental animals].

In the results of complex investigation of the lungs of 26 white rats, it was established, that there is the suppression of surface active properties of surfactant under influence of ethanol. In acute poisoning this suppression is associated with direct injury of surfactant with ethanol and inactivation of surfactant with serum proteins, which appear in the alveolar space because of the edema of air-haematic barrier. In prolonged influence the suppression of the surface activity of surfactant is due to the increase of its catabolism with alveolar macrophages.

Alcoholic Intoxication↗
PubMed1988

[Ultrastructure of the blood-air barrier in comparison with the indices of surfactant surface activity].

Ultrastructure of the air-blood barrier and surface surfactant activity were studied at different time periods of nonspecific inflammation of the lungs in guinea pigs. The animals were sacrificed 3 days, 2 weeks and 1, 2 and 4 months after beginning of the experiment. It has been demonstrated that in early periods of lung inflammation there was edema of all components of the air-blood barrier. Subsequent development of inflammation is accompanied by surface activity decrease associated with dystrophic changes in the epithelial cells of alveoli. At the same time there are compensatory changes in the lungs, directed to eliminate deficiency of surfactant.

Animals↗
PubMed1986

[Surface activity of the surfactant in experimental compression atelectasis].

Surface surfactant activity was studied at different time periods of compression atelectasis, induced by hydrothorax in 35 guinea pigs. The animals were slaughtered 30 and 60 minutes or 3, 12 and 24 hours after hydrothorax. It has been demonstrated that experimental compression atelectasis is accompanied by surface activity lowering, associated with disorders in surfactant secretion into the alveolar lumen. The qualitative composition of surfactant phospholipids remains unchanged, which may play an essential role in the recovery of lung tissue aeration.

Animals↗
PubMed1978

[Histocytochemical features of immunopathologic changes in inflammation of the lungs].

The authors present the results of a comparative cytochemical study of the phagocytes' and lymphocytes' lysosomal membranes state in the rabbit blood, trachea and lungs in immunization with sorbed staphylococcus toxoid and human serum albumin in experimental pneumonia and in this disease against the background of immunization. It was shown that the changes resulting from immunization (the phagocytes' and lymphocytes' lysosomal membranes systemic destabilization, microcirculatory disorders, and cell infiltration in the lungs) were premorbid to pneumonia and intensified the inflammation. The authors considered these changes to be structural and functional signs of the immunopathological reactions accompanying pneumonia.

Acid Phosphatase↗
PubMed1978

[Changes in the peripheral blood lymphocytes after immunization and its effect on the course of experimental inflammatory process in the lungs].

It was shown that in the immunization of rabbits with sorbed staphylococcus toxoid and human albumin, at the height of the immune response there occurred an intensification of biosynthesis and destabilization of lysosomal membranes of blood leukocytes, with a simultaneous development of microcirculation disturbances in the lungs. Development of pneumonia against the background of immunization led to a greater destabilization of the lysosomic membranes of leukocytes and to the intensification in the lungs of infiltrative and destructive processes, in comparison with the course of inflammation in the nonimmunized animals. Peculiarities of the antigens used caused some specificity in the course of pneumonia. A relationship between the changes of blood leukocytes and disturbances in the lungs in immunization is supposed.

Acid Phosphatase↗
PubMed1976

[Morphology of pneumopathies and their role in the development of asphyxia neonatorum].

Histories of deliveries and development records of 44 newborns with penumopathies who had died on the first days of life in the presence of phenomena of the syndrome of respiratory disorder were analysed and the newborns' lungs were morphologically investigated. The investigation made it possible to single out the following forms of pneumopathy in newborns: edematous-hemorrhagic, hyaline, atelectatic, aspirated, and mixed. In the majority of cases the syndrome of respiratory disorder was a sequela of hypoxia of the intrauterine origin which continued during the first hours and days of life after birth. Such "primary asphyxia" may lead to the development of pneumopathy in a neonate. On the other hand, "secondary asphyxia" in many cases represent sequelae of penumopathy destructural and functional immaturity of the pulmonary tissue, hypoxia, a higher permeability of vessels of the microcirculatory bed, spasm of small pulmonary arteris contributed considerably to the development of penumopathies.

Asphyxia Neonatorum↗