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Biomedical subjects

M M Mirrakhimov

Publications and source records attributed to M M Mirrakhimov.

At least 19 recordsLinked to original sources

[Functional morphology of resistant pulmonary vessels and capillaries in individual and species adaptation to high altitude].

Morphological and structural rearrangement of resistant pulmonary vessels and alveolar capillaries was assessed in lowland animals (rabbits) during high-altitude adaptation, in aboriginal high-altitude species (yaks, mountain goats) and on native highlanders. Structural adaptive developments in pulmonary vessels and capillaries of high-altitude animals contribute to maximal facilitation of gas diffusion. Similar adaptive changes in pulmonary resistant vessels and capillaries of laboratory animals and in native highlanders are associated with pathological alterations manifest in the elevation of pulmonary vascular resistance, right ventricular hypertrophy, increases in the thickness of the basal membrane of the air-blood barrier. In all the subjects studied the process of high-altitude adaptation is associated with hypertrophy of pulmonary endothelium. The intensification of pulmonary endothelium. The intensification of pulmonary endothelium metabolic activity may be directed at regulation of vascular tone.

Adaptation, Physiological

[The treatment of hypertension by adaptation to high-altitude hypoxia].

Ethnically close male populations aged 30-59 years who reside in high mountains (2800-3600 m above the sea level) and in low lands (800-900 m above the sea level) of the Tien Shan and the Pamirs were screened. The incidence of essential hypertension was found to be significantly lower (4.2%) among the highlanders than in the lowlanders (15.4%). In highlanders, hypertension is characterized by a high concurrence with high-altitude arterial hypertension and right ventricular hypertrophy. Daily urinary aldosterone excretion is substantially lower in residents of high mountains and natriuresis is higher than that in those from low-lands. Sixty-eight patients with mild hypertension took daily treatment as pressure chamber uplifting (3200 m above the sea level; pO2 112 mm Hg) for 15 days and 45 patients with moderate hypertension were treated with medium-land (1600 m; pO2 134 mm Hg) adaptation for 24 days. Pressure chamber hypoxic training and medium-land adaptation in 69% of patients with mild hypertension and 64.4% with moderate hypertension without signs of target organ lesions produced steady antihypertensive effects, a steady-state (for a 1.5-year follow-up) decrease in cardiac mechanical work, peripheral vascular resistance, arterial impedance, and an improvement of physical fitness. It was proposed to use hypoxic (pressure chamber and high-altitude) training for the treatment of early hypertensive disease and its secondary prevention.

Adaptation, Physiological

PTC-tasting ability in populations living in Kirghizia with special reference to hypersensitivity: its relation to sex and age.

The dimorphism in sensitivity to PTC, with a dilution scale up to 29, was studied in 320 male and 320 female Kirghiz students, 45 male and 200 female Russian students in Frunze, and in 734 Kirghiz schoolchildren in a high-altitude area of South Kirghizia. Gene t frequency was 0.44 for the Kirghiz students, 0.56 for the Russian students, and 0.54 for the Kirghiz schoolchildren. In all the groups studied it was established that such factors as sex and age have no modifying effect on sensitivity to PTC and the pattern of the distribution of sensitivity. In all the groups the frequency of 'tasters' exceeded that of 'nontasters.' Among the Kirghiz students there was a very small percentage (1.2%) of hypersensitive subjects (dil. No. 18), while 14.1% of the Kirghiz children of one Kyzyl-Dzhar school were hypersensitive. Genealogical studies showed that all the hypersensitive subjects belonged to one small stock and lived in the same village. Family studies of probands suggest the existence of a new (third) allele (T2) which determines hypersensitivity to PTC.

Adolescent

[Human ecological cardiology].

Human ecological cardiology studies the interaction of the cardiovascular system and its regulating apparatus with the natural environment to clarify their morpho-functional formation, the mechanisms of the development of disorders and their adequate correction and the use of this natural environment for therapeutic and prophylactic purposes. Problems of adaptation of the cardiovascular system to extreme environmental conditions (high-altitude hypoxia) are discussed. Four groups of trace reactions in adaptation to the environment are described. High-altitude pathology of the cardiovascular system is systemized.

Adaptation, Physiological

[Effect of obsidan on the cardiovascular system under conditions of high-altitude hypoxia].

The effect of beta-adrenergic block on the circulatory reactions of a human being induced by high altitude hypoxia was studied by multi-channel rheography and indirect determination of systolic pulmonary arterial pressure. In healthy people not subjected to a pharmacological effect, 25-day stay at an altitude of 3,200 m was marked by an increase in cerebral blood flow at the beginning of adaptation and the development of pulmonary hypertension the maximum signs of which were recorded during the first days in the mountains. Daily intake of 80 mg of obsidan begun 3 days before the ascent levelled out the adaptative increase in cerebral perfusion and intensified the marked character and stability of hypoxic pulmonary vasoconstriction. It is concluded that great care should be exercised in giving obsidan at high altitude to individuals with even latent forms of right ventricular pathology since under conditions of hypobaric hypoxia beta-adrenergic block increases the load suffered by the right ventricular myocardium.

Adaptation, Physiological

[Change in the ultrastructure of rat myocardium under the influence of 12-months' adaptation to high altitude].

The right and left ventricle myocardium of rats was studied in the course of a 12-month period of adaptation to high altitude (3200 m above the sea level). A long-term exposure of the animals to the high altitude led the development of ventricular hypertrophy mostly of the right, and partly of the left ventricle. Hyperplasia and hypertrophy of individual organellae, particularly mitochondria, were found in most cardiomyocytes of both ventricles. In animals adapted to the high altitude the mitochondrial succinic dehydrogenase activity was more pronounced than in control ones. The results obtained testified to the enhanced intracellular metabolism reflecting myocardial compensatory adaptive responses.

Adaptation, Physiological

[Mechanism of the hypercoagulation effect of hyperoxia].

It was shown in man and rabbits that a 30-minute inhalation of a 100% O2 under normal atmospheric pressure was accompanied by an elevation of the blood coagulation capacity and a sharp reduction of the count of platelets with the change of their structure. The trigger mechanism of the described hypercoagulation effect is possibly the viscous metamorphosis of platelets developing under the effect of oxygen activation of Hageman's factor.

Animals

[Clinical and instrumental characteristics of primary high altitude arterial pulmonary hypertension].

The clinical pattern of primary high altitude pulmonary arterial hypertension observed in permanent residents of mountain regions is described. The diagnostic value of some non-invasive instrumental methods in primary high altitude pulmonary artery hypertension is analysed: electro- and vectorcardiography, rheopulmonography, and indirect pulmonary artery pressure determination. It is suggested to distinguish the labile, stable and decompensated forms of the disease on the basis of its clinical and functional peculiarities. The criterion for the initial two forms consists in the persistence of the pulmonary artery pressure elevation, while the latter form is established when the high altitude cor pulmonale gets decompensated. Functional vasoconstriction of the pulmonary resistive vessels was shown to play an important role in the genesis of the disease: the administration of 0.5 mg of nitroglycerine and a 5-minute oxygen inhalation caused a positive dynamics in the indices of the pulmonary rheogramme and a reduction of the pulmonary artery pressure, which did not reach the level of the plane inhabitants, though.

Adult