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Biomedical subjects

O V Korkushko

Publications and source records attributed to O V Korkushko.

At least 19 recordsLinked to original sources
PubMed2005

[Age peculiarities of cardiorespiratory system reaction to hypoxia].

Age peculiarities of cardiorespiratory system reactions on isocapnic hypoxia (inhalation of gas mixture of 12% O2) have been investigated. It has been stated that breathing with hypoxic mixture resulted in more significant shift of O2 blood saturation, AP and autonomic balance in the elderly people (p < 0.05) comparing to the young people. It testifies to a greater intensity of sympathoadrenal system at hypoxic stress in elderly people that confirms the decrease of their tolerance to hypoxia.

Adaptation, Physiological↗
PubMed2004

Effect of peptide preparation epithalamin on circadian rhythm of epiphyseal melatonin-producing function in elderly people.

Circadian rhythm of plasma melatonin concentrations in healthy elderly subjects was studied before and after a course treatment with Epithalamin (peptide preparation from the pineal gland). Epithalamin modulated the melatonin-producing function of the pineal gland. During the dark period plasma melatonin concentration increased in subjects with initially lowered activity of the pineal gland, while in subjects with normal epiphyseal function plasma melatonin concentration tended to decrease.

Aged↗
PubMed2004

Effect of epithalamin on circadian relationship between the endocrine function of the thymus and melatonin-producing function of the pineal gland in elderly people.

The effect of epithalamin on circadian rhythms of thymic serum factor titers and melatonin concentrations in the blood of elderly people was studied. Course treatment with epithalamin modulated the rhythm of the thymic endocrine function. The increase in the titer of thymic serum factor at night coincided with the increase in blood melatonin concentration and shift of its acrophase to 3.00, which was characteristic of young people. In elderly people with preserved nocturnal peak of the thymic serum factor titer before therapy the nocturnal (3.00) concentration of melatonin was high and did not change after drug therapy. The correlation between melatonin concentration and titer of thymic serum factor increased after epithalamin treatment.

Aged↗
PubMed2004

[Mechanisms of nitric oxide activity in cardiovascular system as a basis of pathogenetic therapy of related diseases].

General characteristics and mechanisms of effects of nitric oxide (NO) and its role in the development of pathology are reviewed. Presented are the data about NO participation in the regulation of circulation and cardiovascular system; NO-dependent mechanism of regulation of cardiovascular reactivity against the background of dysfunction of endothelium; cGMP-independent mechanism of NO effect upon Ca homeostasis and the sensitivity of myofibrils of smooth muscle cells to Ca ions; pharmacological correction of disturbances of NO metabolism and related endothelial dysfunction; role of age changes of the endothelial function in the development of cardiovascular pathology.

Animals↗
PubMed2004

[Age dependent dynamics of the critical points of physical exercise in healthy men].

Age dynamics of the critical points of an exercise in 240 apparently healthy men aged 18-95 years was investigated. It is shown that linear decrease of a level of critical load capacity, maximum oxygen consumption, thresholds of anaerobic exchange and decompensated metabolic acidosis takes place in aged individuals. The equations of linear regression of changes in these parameters with age are presented. Using the method of factor analysis it is demonstrated that in healthy men variability of critical points of physical activity is age-dependent. Age factor determines 58% of maximum oxygen consumption variability, 62% of decompensated metabolic acidosis variability and 51% of anaerobic exchange variability. At the same time 23% of maximum oxygen consumption variability, 26% of threshold of decompensated metabolic acidosis variability and 33% of threshold of anaerobic exchange variability depends on physical activity level.

Adolescent↗
PubMed2004

[Some mechanisms of the development of endothelial disfunction in aging].

Taking into consideration age-related changes in endothelium, the ability of endothelium to produce vasoactive substances has been studied in healthy subjects of various age. Under experimental conditions, the activity of constitutive and inducible NO-synthase has been studied as well. The clinical part of the study involved investigation of 38 healthy subjects aged 60-79. The study has been designed to investigate vasomotor function of the endothelium, the levels of endothelin-1, NO2, prostacyclin, thromboxan, the level of adhesive molecules and inhibitor of tissue plasminogen activator. The levels of endothelial and inducible NO-synthases in tissues of the myocardium and the aorta has been investigated in healthy rats of various age. The data obtained show a decrease in the production of relaxation factors: NO and prostacyclin with aging. An important mechanism of deterioration of NO-synthesizing function of the endothelium is a decrease in endothelial NOS activity. The synthesis of endothelial vasoconstricting agents increased with ageing. This in combination with decreased production of vasodilating substances results in deterioration of defence properties of the endothelium. The increase in titer of adhesive molecules and inhibitors of tissue plasminogen activator testifies to age-dependent deterioration of anti-inflammatory and antithrombotic activities of the endothelium.

6-Ketoprostaglandin F1 alpha↗
PubMed2004

[Circadian rhythms of pineal gland melatonin-forming function in healthy elderly people].

Circadian rhythms of pineal gland melatonin-forming function were studied in healthy elderly people (n=31, age range 60-74 years). The blood plasma melatonin concentration was determined by means of radioimmune method at 3.00, 9.00, 15.00 and 21.00. The study revealed two types of circadian rhythms of plasma melatonin concentration: a high-amplitude (29%) and a low-amplitude (71%) ones. The high-amplitude rhythm of melatonin-forming pineal gland function was observed in elderly people with a higher physical working ability and a lower functional age of cardiovascular system. It is advisable to conduct the correction of pineal gland melatonin-forming function in elderly people with low-amplitude circadian rhythm of plasma melatonin concentration.

Aged↗
PubMed2003

[Characteristics of hypoxia development in aged people].

The aim of the study was to investigate the peculiarities of tissue oxygen provision on the level of microcirculatory bed and to determine the significance of the indices taken separatively in pathogenesis of hypoxia in practically healthy elderly people. The study comprised 30 practically healthy people aged 60-74. It included investigation of oxygen tension in peripheral tissues, skin and bulbar microcirculation, functional state of endothelium in the group of elderly healthy people. The results obtained were compared with analogous data obtained in practically healthy young subjects. The tissue oxygen provision was found to decrease with age.

Aged↗
PubMed2003

[Effect of hypoxia on respiration system in aging].

The purpose of the research was to investigate the peculiarities of ventilatory reaction to hypoxia with the elderly and old people. 27 practically healthy young (20-35 years), 24 elderly (60-74 years) and old (older 74 years) people were examined. The influence of hypoxia on the gas exchange was investigated during the respiration of gas mixtures with 17% and 12.5% of oxygen content (during 12 minutes), that corresponds to 1500 m and 4000 m above sea level. The parameters of ventilating function of the lung were determined on the spirograf CT-1M. Oxygen tension in arterial blood (PaO2) was determined with the device "AVL" by "OMNI" (Austria). The curves of ventilating dependence on PaO2 for the young and old people are plotted using the mathematical model. It was shown, that with aging the "steepness" of curve's dependence on the ventilatory answer from the degree of hypoxemia decreases, that testifies to the decrease of chemoreflex sensitivity.

Adult↗
PubMed2003

[Circadian pattern features of paroxysmal atrial fibrillation in elderly patients with ischemic heart disease].

Forty-eight elderly patients with IHD and paroxysmal atrial fibrillation were studied to determine circadian pattern of arrhythmia onset. The data were obtained by detailed interview and analysis of medical documents. The found variations were fitted to cosinusoidal function with a period of 24 hours Y = 9.75 + 3.5cos(2 pi t/24 + 0.2) (R2 = 0.69; F = 10.2; P < 0.01; two first coefficients of equation are significant by t-test, P < 0.01), the peak of arrhythmia onset was observed about midnight. 59.8% of overall number of episodes developed at dark period of day (P < 0.05). Findings testify that time periods of arrhythmia onset increase in number with disease evolution. It may be an additional criterion of paroxysmal atrial fibrillation transformation into its permanent form.

Aged↗
PubMed2003

[Age-related changes in fatty acid composition of the erythrocyte membrane].

Taking into account the prerequisites existing in elderly people for disturbances in metabolism of polyunsaturated fatty acids (PUFA) which are risk factors of cardiovascular pathology, we studied the content of separate fractions of fatty acids (FA) in erythrocyte membrane of practically healthy people aged over 60. Seventeen practically healthy subjects aged 60-74 were investigated. All of them have been under long-term observation at the Institute of gerontology, AMS of Ukraine. A thorough preliminary examination proved them to be free from any pathology which might affect the results of studying the lipid composition of erythrocyte membrane. Twenty healthy subjects aged 20-29 served as controls. The fractions of FA as well as HDL and LDL were determined in erythrocyte membrane. In elderly healthy people the results obtained have shown a statistically significant decrease in the content of unsaturated FA and PUFA in erythrocyte membrane. The level of PUSFA decreased due to both omega-6 and omega-3 fractions as well as at the expense of their precursors. However, the decrease in the level of omega-3 fraction was more pronounced. As evidenced by a decrease in the content of unsaturated FA and PUFA in lipoproteins of both high and low density, the disturbance of PUFA transport by lipoproteins is one of the mechanisms of the decrease in PUFA level in the erythrocyte membrane.

Adult↗
PubMed2002

[Significance of changes in individual indicators on intravascular homeostasis in development of circulatory hypoxia in aging].

The study comprised 45 healthy subjects aged 60-74. It was designed to examine the state of skin and bulbar microcirculation using the method of television capillaroscopy. The functional state of endothelial microvessels was studied with the help of laser doppler flowmeter by means of functional tests with postocclusion hyperaemia and intradermal injection of epinephrine solution in the dose of 0.1 ml (1.10-6 mol/l). The platelets aggregation activity was studied using the method of turbidimetry. The blood viscosity and functional state of erythrocytes were determined with the help of rotary viscosimeter at the shift velocity of 10 to 200s-1 with estimating the erythrocytes deformability and aggregation indexes. Oxygen saturation of the subcutaneous fat fibers was studied by polarography. It has been found that the increase of adrenalin-induction aggregation of platelets, the decrease of erythrocyte deformation and the endothelium synthesis disturbance caused relaxing factors play role in the circulatory hypoxia development.

Adult↗
PubMed2001

[Age-related changes in the morphology and functional state of the heart].

The aim of this study was to assess age-related morpho-functional peculiarities of the heart on the basis of investigating the chrono-inotropic dependence of left ventricular [LV] myocardium. The results of this investigation are of importance for geriatric practice. They are necessary for determining the markers and elaborating the quantitative criteria of detecting the early stages of heart failure and finding the ways to its correction in elderly people. Twenty subjects aged 20-35 and forty four subjects aged 60-74 without clinical symptoms of cardiovascular pathology were investigated by means of stress-echocardiography. The indices of systolic and diastolic functions of the heart were studied by means of the transesophageal atrial electric pacing (TAEP) at baseline and at each frequency of pacing with the assessment of degree and type of LV myocardium hypertrophy. In all of the subjects investigated the results of TAEP were negative, i.e. they showed no signs of coronary insufficiency. In elderly people the increment values of contraction and relaxation velocity indices at the same pacing frequency were significantly lower (P < 0.05) in comparison with ones obtained in younger subjects. In elderly people a decrease of the maximal relaxation velocity occurred at submaximal age-related heart rate (on the average 135 beats/min) as compared to intermediate pacing frequencies whereas in younger subjects a further increment of this value continued. The LV hypertrophy developing with ageing plays on the one hand a compensatory role but on the other hand it deteriorates the diastolic function. The inefficiency of work of the old heart while pacing is an important factor limiting functional capabilities of the heart.

Adult↗
PubMed2000

[Morphological changes of gastric mucosa in duodenal ulcer disease in elderly and senile patients].

Morphological investigation of gastric mucosa was done in 85 patients of various age with duodenal ulcer disease using visual-analogue scale of the modified classification of the Sidney system (1996). In all the patients there was revealed chronic gastritis, possessing age morphological peculiarities. The frequency of infectionizing with Helicobacter pylori is reduced with the age increased.

Aged↗
PubMed1998

Incorporation of urea nitrogen into fecal protein and plasma protein amino acids in elderly human volunteers after ingestion of lactic acid bacteria.

Health effects of fermented milks have been associated with the metabolic activity of lactic acid bacteria in the gastrointestinal tract. It has been proposed that an increased excretion of urea nitrogen via microbial protein may decrease the workload on kidneys and liver. Therefore, a study was carried out in healthy elderly human subjects to investigate the incorporation of [15N2]urea nitrogen into plasma and fecal proteins and amino acids. Over a period of 10 d 13 healthy elderly subjects ingested daily a freeze-dried microbial preparation which contained different genera of lactic acid bacteria and is used to produce fermented milk products. One of the strains was originally isolated from stool samples of elderly people from the Caucasus region (Lactobacillus plantarum). No stimulation of fecal protein-nitrogen excretion and no increase in 15N-abundances in fecal protein was measured following the administration of the viable microbial preparation and a [15N2]urea bolus. Tentatively, it was concluded that this may have been caused by the inability of the microbial culture to survive the gastro-intestinal passage and (or) by the absence of additional fermentable carbohydrates in the diet as energy source for bacterial protein synthesis in the large intestine. However, using a highly sensitive GC-C-IRMS method we observed a significant incorporation of 15N into plasma protein amino acids. 15N-Enrichments in single amino acids were found according to their participation in transamination reactions. The slight enrichment of lysine which is not transaminated in mammalian tissues may indicate a microbial synthesis and absorption of bacterial lysine.

Aged↗
PubMed1995

Reaction of pituitary-adrenal and autonomic nervous systems to stress in trained and untrained elderly people.

The changes of hormonal and autonomic nervous systems in trained and untrained elderly people were studied. An exercise tolerance test was used as a model of physical stress. Elderly people were more sensitive to the influence of stress factors. The hemodynamic reaction at the same workload was more economical in trained subjects. Also, the reaction of the autonomic nervous system and pituitary-adrenal system was less pronounced in trained elderly people. It was established that physical training in aging increases the resistance to stress.

Adrenal Glands↗
PubMed1995

[Pulmonary ventilation function in middle-aged and elderly patients with chronic bronchitis].

The indices of lung ventilation and biomechanics of breathing were determined in 48 patients with chronic obstructive bronchitis (COB) aged 60-79 and 45 healthy subjects of the same age. Inpatients with COB a rise of lung ventilation, work of breathing, ventilation equivalent, positive reaction to oxygen, a decrease of maximal breathing capacity and reserve of breathing take place that reflect excessive and uneffective ventilation, limitation of its functional performance. These specific features are due to an increase in the total lung capacity at the expense of residual volume against a decrease of vital capacity with diminution of alveolar ventilation to lung ventilation ratio. But of decisive significance was disturbance of bronchial patency manifesting in a decrease of Tiffeneau index, midexpiratory flow, respiratory flows in forced respiration, especially in expiratory phase, concavity of flow-volume curve to volume axis, a rise of bronchial resistance.

Aged↗