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G S Shishkin

Publications and source records attributed to G S Shishkin.

At least 19 recordsLinked to original sources
PubMed2002

[Age changes in interalveolar septa and their relationship to a decrease in gas exchange].

External respiration and interalveolar septa ultrastructure were examined in healthy men aged 45-49 and 60-70 years. Involution reduction of static lung volumes, decrease in lung ventilation capacity and deceleration of gas exchange in the respiratory portion of the lung were noted. Age changes in interalveolar septa capillary network structure, air-blood barrier and the interstitium have been established. In the elderly people, the capillary network was found to lose some small loops, which were substituted by a connective tissue. The thickness of air-blood barrier was shown to increase, thus causing a deceleration of oxygen diffusion from alveolar lumen into the blood of pulmonary capillaries. The interstitial connective tissue was found to contain a larger proportion of collagen and, particularly, of elastic fibers per unit volume. In the aged persons interalveolar septa underwent obvious sclerotic changes, and the disappearance of Kohn pores could be considered as one of their manifestations. All these changes seem to disturb the uniformity of intraacinar ventilation and may significantly influence gas exchange conditions.

Aging↗
PubMed2001

Seasonal variations in respiratory system in healthy inhabitants of west Siberia.

The aim of this work was to investigate seasonal variations in oxygen consumption, ventilation, lung volumes and their relationships in healthy adult inhabitants of West Siberia. The investigations were performed in Novosibirsk. Thirty healthy male adult volunteers were studied 4 times during a year: in summer (mean monthly temperature +20 degrees C), autumn (+2 degrees C), winter (-18 degrees C), and spring (degrees C) under the same conditions in a room at rest. Oxyspirography, pneumotachography and the helium dilution method were used. Oxygen consumption (VO2), breathing frequency, vital capacity (VC) and inspiratory capacity were adjusted to be the same during the year. Minute ventilation (Ve), VO2-Ve ratio, residual volume (RV) and expiratory reserve volume (ERV) to RV ratio had dynamics concurrent with seasonal temperature dynamics. Tidal volume, ERV, functional residual capacity, forced 1-s expired volume (FEV1) and FEV1/VC also changed, but their dynamics were different from the previous parameters. The minimum value of these parameters was found in the spring and the maximum--in the autumn, or summer and autumn. Correlations between respiratory parameters also changed during the year. We conclude that oxygen consumption is provided by reorganisation of pulmonary tissue in winter.

Adult↗
PubMed2001

[Bronchial parameters in inhabitants from the North].

The number of branches in the bronchial tree as a whole and in each generation was calculated on corrosion preparations of the right lung in 16 male inhabitants of Novosibirsk and Magadan. Diameters and lengths of a trachea, main, lobar, segmentary and subsegmentary bronchi, interlobular, lobular and terminal bronchioles were determined. The parameters of the 9 first generations were measured completely while those of distal airways--by 15% occasional choice. In both groups the number of branches in the generation was established to grow proportionally to generation number growth and then to decrease due to asymmetry of branches and termination of the part of them at the level of terminal bronchiole. In Magadan inhabitants bronchial tree was longer and wider. The anatomical dead space was 1.6 fold larger in North inhabitants than in that of Novosibirsk. Comparison to physiological data shows that in Novosibirsk inhabitants anatomic dead space makes 27% of respiratory volume, while in that of Magadan--34%. As a result the volume of the air inhaled in North inhabitants which is blended in airways is greater than in Western Siberia people.

Arctic Regions↗
PubMed2001

[Architectonics and parameters of interlobular bronchioles in residents of western Siberia].

Architectonics and parameters of interlobular bronchioles (ILBs) were examined in corrosion and histological preparations of the right lung in 13 male residents of Novosibirsk died from accidents. It was demonstrated that ILBs were present in all pulmonary segments and subsegments and were carrying the air from subsegmental bronchi to lobular bronchioles. According to architectonics, ILBs could be divided into three types: trunk, scattered and mixed. Majority of ILBs belonged to the trunk type (65-66%), while scattered and mixed types were less frequent (constituting 13-14% and 20-21%, respectively). Right lung contained 230-250 ILBs. The number of lobules stemming from one ILB varied from one to twelve. The average ILB had 3.4 +/- 0.1 branches and was found to ventilate 5.3 +/- 0.3 pulmonary lobules. Parameters of I and II order ILBs were measured separately. No significant differences in the mean ILBs diameters in different lobes and segments were detected. Regularities in length distribution were not found.

Bronchi↗
PubMed1999

[Structural organization of a human lung lobule].

Structure and number of human lung lobules were investigated in corrosion preparations and by the method of 3-dimensional reconstruction using serial sections. It was established that the bronchial tree branches inside the lobules 4 to 6 times forming 3 to 5 orders of intralobular bronchioles and 1 order of terminal bronchioles. Structure of lobules in all human lung lobes is identical and has a repeating group of bronchial branches as a basis. The lung lobule consists of 8 to 20 acini. In the right lung the average of lobules numbers is 1200.

Adult↗
PubMed1998

[The protective reaction of external respiratory system to the long-term action of ecological factors].

Analyzes physiological manifestations and mechanisms of defense reaction of the external respiration system in response to two ecological factors: low air temperature and dust. Clinically healthy men (without clinical and laboratory signs of lung disease) were examined, living or working under conditions of low temperature or high dust content in the air. These two factors cause mobilization of reserve tissue of respiratory compartments of the lungs by involving the reserve acini in ventilation. This brings about an increase in FRC and RV, thus decreasing the harmful effect of the ecological factor and impairing gas metabolism in the lungs. Compensatory hyperventilation develops in response to it, expressed in increase of minute ventilation and decrease of ventilation efficiency. Competitive relationships between defense reaction and gas metabolism lead to external respiration stress.

Cold Temperature↗
PubMed1998

[Features of the structure and parameters of the intra-alveolar septa in residents of Western Siberia].

In inhabitants of Novosibirsk and Moscow district intraalveolar septum, the basic functional element of the lung consists of interstitial connective tissue and capillar network, limited with basement membranes, on which cells of epithelial lining are placed. There are no principal differences in septal structure between individuals from both regions. The majority of morphometric parameters are statistically similar, although certain peculiarities were noted in human subjects from Siberia, the most important of which is that air-blood barrier in them is 33% thinner than those in inhabitants of Moscow district. Majority of capillaries possess the air-blood barrier from both sides. This increases diffous capacity of the lungs and blood oxygenation level.

Adult↗
PubMed1997

Morphological peculiarities of respiratory compartments of arctic animal lungs.

BACKGROUND: Morphological and ultrastructural peculiarities of interalveolar septa in endemic arctic animals (reindeer, polar fox, lemming) are compared with laboratory animals (rat,dog). METHODS: For light microscopy, tissue samples were taken from the central and peripheral sections of all lobes of the right lung. They were fixed in 10% neutral formalin and embedded in paraffin. For electron microscopy, samples were taken from subpleural sections of the caudal lobe of the right lung, fixed in 4% paraformaldehyde for 24 hours, subsequently postfixed in 2% OsO4. for 2.0 hours. Samples were dehydrated in acetone and embedded in a mixture of Epon 812 and Araldite. Ultrathin sections were photographed at a magnification of x4,000. For each interalveolar septum, lengths and diameters were recorded and the squares of septa surface, air-blood barrier surface and the number of the structures were determined. The topography of capillaries and the ultrastructure of interstitium were described. RESULTS: Acini in the arctic animals (reindeer, polar fox, lemming) are compact. In all lobes they are fully expanded and uniformly filled with air. There is no physiological atelectasis. Alveoli appear straight and homogeneous in form and size. In the polar fox, the quantity of interalveolar pores of Kohn is twice that in the dog. The number of pores in the lemming are similar to those in the rat but their size is 1.6 times greater in diameter. In arctic animals more capillaries connect with both alveolar surfaces by an air-blood barrier and simultaneously participate in the gas exchange of two adjoining alveoli. In the polar fox and lemming the thickness of the air-blood barrier is 1.3-1.4 times less than that in the dog and rat. CONCLUSIONS: The set of morpho-functional peculiarities of the acini of arctic animals allows for an increase in gas exchange in the respiratory compartments of the lungs and provides necessary oxygenation of arterial blood at a low partial pressure of oxygen in the alveolar gas.

Animals↗
PubMed1992

Macrostructure differences of polar fox and dog lungs.

The lungs of the polar fox and dog have the typical form and lobular structure characteristic of beasts of prey. Both display secondary fusion of the cranial and middle lobes in the left lung, but this is more extensive in the fox. A consistent relationship between the beast body mass and the mass and volume of the lungs is present. The relative weight of dog lungs independent of body size (weight index) is 1.7 times that of the polar fox. In the latter the parenchyma is much more subdivided than in the dog. There are 23 segments per lung pair in the polar fox, compared to 19 in the dog. Although these are of unequal size throughout the lungs of both species, corresponding segments in the fox are about half as large as those in the dog. The greater segmentation of polar fox lungs may be of assistance in restricting the spread of inflammatory processes.

Acclimatization↗
PubMed1989

[Quantitative analysis of the bronchial tree structure in dogs and polar foxes].

Bronchial tree in the blue fox possesses a more complex structure that that of the dog and is characterized with a greater length and a greater number of generations in large and middle bronchi with a simultaneous decrease in the number of small bronchiole generations and a greater irregularity and asymmetry within segments. These peculiarities are connected with ecologically ensured in the North demands on increase of anatomically dead space.

Animals↗
PubMed1988

[Ecological characteristics of the structural organization of respiratory segments of the lung].

The structure of the bronchial tree in the lung lobules has been studied and the number of lobules and acini in different lobes and in the entire lung has been determined in polar foxes and dogs. Branching pattern and the number of generations of interlobular and intralobular bronchioli have been defined. It has been found that the number of lung lobules in polar foxes was twice as high as in dogs, the lobule volume being smaller almost by half. A smaller number of acini in polar fox lobules enables the central regulation mechanisms to intensify the control of local ventilation. It broadens the possibilities for physiological responses to the influence of climatic factors of the Extreme North.

Animals↗
PubMed1986

[Features of the architectonics of the bronchial tree of the polar fox as a manifestation of adaptation of the lungs to northern conditions].

Peculiarities of the bronchial tree architectonics as a whole and in the pulmonary lobes have been studied in the animal of the Arctic zone--the Arctic fox in comparison with the dog. Certain species-specific differences in the form and branching of the bronchial tree have been stated. In the Arctic fox the subsegmentary bronchi are more developed, they are longer, with greater number of branchings and, thus, more interlobular bronchioles run off from them. Besides, up to 10% of interlobular additional bronchioles take their origin from the segmentary bronchi and as a result the bronchial tree of the Arctic fox is 1.5 times as thick as that of the dog. Complexes of the branches in the subsegmentary bronchi, or in large interlobular bronchioles of the Arctic fox are well isolated from each other and make the base of the subsegments of two types. The architectonic peculiarities are connected with genetically secured adaptation of the animal to low temperature of the environment, since they improve warming and mixing the inhaled cold air with the warm alveolar air.

Adaptation, Biological↗
PubMed1981

[Comparative electron microscopic study of interalveolar septa in Arctic foxes and dogs].

Structure of the interalveolar septa in the lungs of typical representatives of the Arctic Zone--Arctic foxes--has been studied electron microscopically in comparison with those of dogs from the middle zone of West Siberia. Structure and parameters of the dog pulmonary septa correspond to modern notion on ultrastructure of the respiratory system in animals of middle latitudes. In the Arctic fox a certain combination of morpho-functional peculiarities is observed contributing to an increased diffuse power of the lungs. The capillary ultrastructure of the animal is considerably changed. capillaries with double aerohematic barrier make a greater part of the capillary network (57%), area of the barrier is nearly twice as large (in dogs--37%, in Arctic foxes--65%). A great amount of Cohn's pores in the Arctic boxes (twice as great as in the dogs) is a peculiar feature for the Arctic fox pulmonary septum. The morpho-functional peculiarities stated contribute to an increased diffuse rate and to better saturation of blood with oxygen.

Animals↗
PubMed1976

[A quantitative electron microscopic study of the respiratory parts of the lungs. II. The capillary network and septal spaces of the interalveolar septa].

A parallel histological and electron microscopic study of the capillary network of interalveolar septa has shown that in this microstructure there is only one two-dimensional capillary network, common for adjacent alveoles. In septal spaces of interalveolar septa the collagenic fibrils form an even thin network and additional collagenic bundles. The latter are mainly found in intercapillary septal spaces. The elastic fibres in interalveolar septa are found rarely, no interstitial cells being found at all.

Animals↗
PubMed1975

[Dimensions and alveolar surface of the ineralveolar septa of the rat lung].

The dimensions of the alveolar surface of interalveolar septa were studied in albino rats. The mean thickness of certain septa range from 3,1 to 6,2 mu, the mean thickness of the septa in different individuals being factually the same. A part of the alveolar surface of the septa represents the air-haematic barrier which occupies 51-64% of the total alveolar surface in different rats. The mean values of all the parameters in the animals studied are very close. It shows that the interalveolar septa are standard structures in their organization and dimensions both in the same animal and in different animals of the same species.

Anatomy, Comparative↗