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Biomedical subjects

E L Lushnikova

Publications and source records attributed to E L Lushnikova.

At least 19 recordsLinked to original sources
PubMed1993

[A stereological analysis of the myocardium in rats adapting to the conditions at high latitudes].

Qualitative and quantitative morphologic analysis of myocardium of Wistar rats were carried out when they have been transferred to high latitudes (being in latitude 69 degrees north during 37 days). It was shown, that already in a day after transferring to high latitudes pronounced disorders of lymph and blood circulations developed and heterogeneity of cardiomyocyte lesions was noted. By the end of the experiment atrophic and necrobiotic cardiomyocytes resorbed by macrophages were registered. In the group of animals, whose were transported in middle latitudes morphologic changes in myocardium gradually increased by the end of the experiment. Stereologic analysis revealed stereotype dynamics of tissue reorganization of myocardium in both animal groups. A key event in tissue reorganization of myocardium was the significant decrease of volume and surface densities of capillaries at 12th day of experiment and as consequence of these changes the volume and surface-to-volume ratios of capillaries to cardiomyocytes were decreased. The decrease of these parameters was more pronounced in animals whose were transported to high latitudes.

Adaptation, Physiological↗
PubMed1993

[A stereological analysis of the tissue organization of the myocardium in long-term adaptation to alpine conditions].

Stereologic study of myocardium of Wistar rats after longterm living (during 10 months) at high altitude (at 3200 m above sea level) was carried out. It was shown that tissue reorganization of left ventricle myocardium under these conditions was characterized by significant decrease of the volume and surface densities of capillaries and endothelial cells, especially after living during 5 months in mountains. Simultaneously the processes of intracellular regeneration in cardiomyocytes were disordered, this manifesting as a rarity and lysis of sarcoplasm and also as atrophy of a part of cardiomyocytes. These changes were more pronounced after living during 10 months at high altitude.

Adaptation, Physiological↗
PubMed1993

[A quantitative tissue analysis of the rat myocardium in whole-body overheating].

The reorganization of Wistar rat myocardium at 3 and 7 days after a single total overheating at a temperature of 43 degrees C was studied using stereologic and qualitative morphological tissue analysis. Most pronounced morphofunctional changes in myocardium were shown to develop 3 days after the exposure such as hemodynamic disorders, lymphostasis, interstitial edema, contracture lesions of cardiomyocytes. The spatial myocardial reorganization was not considerable. At 7 day after exposure, a significant decrease of the heart weight as a result of atrophic changes in cardiomyocytes was recorded. In the same period the most pronounced spatial reorganization of myocardial parenchyma and stroma was noted. The significant decrease of volume density of capillaries was accompanied by some increase of the volume density of cardiomyocytes resulting in a significant decrease of volume ratio of capillaries to cardiomyocytes. Thus, during postheating restitution the atrophy of myocardium developed characterized by an unbalanced decrease of volume densities of capillaries and cardiomyocytes.

Animals↗
PubMed1988

[Ultrastructural and radioautographic research on the skin in acantholysis bullosa].

By means of light microscopy 145 biopsies of skin in acantholytic pemphigus were studied. Electron microscopic and radioautographic study was carried out in 19 cases. It was determined that the whole complex of ultrastructural changes in epidermocytes (impairment of nucleolar apparatus, lysis of cytoplasmic organelles, disappearance of desmosomes) reflects the disturbance of protein synthesis. Radioautographic study in vitro with 3H-uridine and 3H-thymidine revealed the low level of RNA and DNA synthesis in epidermal cells in pemphigus. The data obtained were interpreted with a position from the conception of plastic deficiency.

Adult↗
PubMed1987

[Histostereologic analysis of the myocardium of homoiothermic animals during cooling].

A stereologic study of the myocardium exposure to cold for 4 hours, 8 and 16 days was carried out on Wistar rats. It has been shown that during the first 8 days acute hemodynamic disorders and cardiomyocyte contractures developed. These changes were followed by a decrease in the volume and surface capillary density resulting in the impairment of transcapillary exchange and reduction of the intracellular regeneration processes in cardiomyocytes. By the 16th day the compensatory-adaptive reactions developed, i.e., the volume and surface density of endothelial cells and capillaries was increased. At the same time the lysis processes caused by the general decrease in the inflow of plastic substances to the myocardium due to the increase in thermogenesis were revealed in part of cardiomyocytes. These changes in parenchymatous cells were accompanied by the intensification of desmoplastic reactions in the myocardial stroma.

Animals↗
PubMed1985

[Ultrastructural stereological analysis of the absolute parameters of the cardiomyocytes in myocardial hypertrophy].

Arterial hypertension was produced in male Wistar rats by abdominal aorta ligation. By the 35th day of experiment the animals had developed myocardial hypertrophy. The subcellular organization of cardiomyocytes was studied by electron microscopy and stereology (computation of relative and absolute parameters). In myocardial hypertrophy, the absolute volume of myofibrils, sarcoplasmic reticulum and T system in the left ventricle of the heart was increased, whereas the absolute volume of the mitochondria remained unchanged. The general surface area of all organelles was noticeably increased. The myofibrils and sarcoplasmic reticulum experienced greater changes, which may reflect the features of compensatory processes under the experimental conditions described.

Animals↗
PubMed1984

[Ultrastructural stereological analysis of acute myocardial hypertrophy of hypertensive etiology].

The myocardium of Wistar rats was studied by electron microscopy after ligation of the renal artery resulting in a stable elevation of blood pressure. The ultrastructural data on the development of heart hypertrophy were described within 5 to 35 days after operation using the morphometric and stereological methods and correlation analysis. The hypertrophied cardiomyocytes showed a reduction in the ratio of the total volume density of the mitochondria, sarcoplasmic reticulum and T system to the volume density of myofibrils. It was discovered that hypertrophy of cardiomyocytes is marked by an increase in the sarcoplasmic reticulum rather than in myofibrils and other cell compartments, whereas the relative volume of mitochondria decreases.

Acute Disease↗
PubMed1984

[Stereological analysis of the parenchymal and stromal structures of a hypertrophied myocardium in acute arterial hypertension].

Arterial hypertension in 35 male Wistar rats was produced by disturbance of the left renal artery circulation. Myocardial tissue reorganization was studied by using the methods of light microscopy and stereological analysis. By the 35th day of the experiment marked alterations of the intramural vessels were found which were manifested in the thickening of the vessel walls due to hyperplasia and hypertrophy of the smooth muscles cells, and in the developing of sclerotic processes in all layers of the arterial walls. At the tissue level a decrease of the volume and surface densities of capillaries and connective tissue cells were determined, that resulted in a decline of the ratio between the volume and surface densities of the structures to the volume density of cardiomyocytes. Informational analysis revealed an increase of entropy and relative entropy of the myocardium tissue during its hypertrophy.

Animals↗
PubMed1983

[Quantitative morphological analysis of the development of myocardial hypertrophy in spontaneously hypertensive rats].

Myocardium of normotensive Wistar rats and that of spontaneously hypertensive SHR rats aged 1, 4, and 11 months was studied using light and electron stereological techniques. The volume density of contractile apparatus and sarcoplasmic reticulum was shown to increase while that of the energy-producing compartment to decrease in heart hypertrophy. In the period of considerable hypertrophic growth of cardiomyocytes which coincided with the onset of hypertension the volume densities of capillaries and endothelial cells decreased. A secondary increase of the microcirculatory bed should be considered as a process of stabilization of the quantitative parenchymal-stromal ratios in myocardial hypertrophy.

Animals↗
PubMed1981

[Stereologic ultrastructural and cytochemical study of myocardial hypertrophy during gerontogenesis].

The myocardium of male Wistar rats aged 4, 24 and 33 months was examined using stereological techniques to determine the volume and surface densities of the ultrastructure of cardiac myocytes. Electron microscopy was used to detect succinate dehydrogenase in mitochondria. The myocardium of senescent animals was shown to be hypertrophied. The ratios of the volume densities of mitochondria, sarcoplasmic reticulum and T-system to the volume density of myofibrils in cardiac myocytes considerably decreased with age. The activity of succinate dehydrogenase in mitochondria reduced as well.

Aging↗