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Biomedical subjects

A A Markin

Publications and source records attributed to A A Markin.

At least 19 recordsLinked to original sources
PubMed2005

[Serum creatine kinase levels and the number of sarcolemmal dystrophin disruptions in human skeletal muscle fibers under conditions of weightlessness simulation].

9 male volunteers took part in the experiment. They were divided in two groups. 5 volunteers (control group) have been in "dry" immersion for 7 days. 4 volunteers (stimulated group) in addition to "dry" immersion were treated with artificial support stimulation. We investigated the number of muscle fibers with the disruptions of sarcolemmal dystrophin and serum creatine kinase levels. 7-day "dry" immersion did not change the mean number of muscle fibers with dystrophin disruptions, it led to significant decrease of serum creatine kinase levels and did not influence on the sensitivity of sarcolemma to injury. Artificial support stimulation did not influence on these parameters.

Adult↗
PubMed2004

Serum creatine kinase levels and the number of sarcolemmal dystrophin disruptions in human skeletal muscle fibers under conditions of 7-day "dry" immersion.

9 male volunteers took part in the experiment. They were divided in two groups. 5 volunteers (control group) have been in "dry" immersion for 7 days. 4 volunteers (stimulated group) in addition to "dry" immersion were treated with artificial support stimulation. We investigated the number of muscle fibers with the disruptions of sarcolemmal dystrophin and serum creatine kinase levels. 7-day "dry" immersion does not change the mean number of muscle fibers with dystrophin disruptions, it leads to significant decrease of serum creatine kinase levels and does not influence on the sensitivity of sarcolemma to injury. Artificial support stimulation does not influence on these parameters.

Creatine Kinase↗
PubMed2000

[Lipid peroxidation and activity of diagnostically important blood enzymes in rats during 35 days head-down suspension].

In the experiment with 35-d head-down suspension of rats concentrations of lipid peroxidation (LPO) products and values of antioxidant defense (AOD) parameters were determined in the lever, skeletal muscles, myocardium, and blood plasma. In addition, activity of 11 plasma enzymes characteristics of these tissues was evaluated. LPO was found to be activated in the lever, myocardium and skeletal muscles in the first and 4-5 weeks of suspension. The period between weeks 2 and 4 marked phase variation of LPO intensity which could have baseline or increased values. Plasma LPO was inhibited due to AOD activation pointing to compensatory processes on the level of organism and absence of pathologies in the organs and tissues under study. As a rule, activity of the plasma enzymes directly or indirectly participating in energy metabolism was reduced. Enzymes-catalysts of other types of metabolism predominantly elevated activity during LPO intensification. Canonic analysis established a significant correlation of LPO, AOD and activity of plasma enzymes, and LPO and AOD in the rat's lever and plasma enzymes. These correlations between LPO, AOD and activity of diagnostically important enzymes can be used to diagnose and predict changes in the state of organism caused by simulated factors of space flight.

Animals↗
PubMed1997

[Lipid peroxidation and activity of diagnostically significant enzymes in cosmonauts after flights of various durations].

Concentrations of the products of peroxide oxidation of lipids (POL), indices of the system of antioxidant defence (SAD), and the activity of 13 diagnostically significant organic/tissue specific enzymes (DSE) were determined in blood serum of cosmonauts who had participated in short (5-9 days, n = 8), long (125-179 days, N = 15), and superlong (241-366 days, n = 5) missions. To feature an interrelation of the indices under study, the canonical correlation analysis of a set of POL and SAP parameters and DSE activity was performed. Compared with pre-flight values, changes in the POL and SAP parameters were significant in serum only after the long-duration missions. Signs of POL activation were noted following the superlong missions. After the long-duration missions increased was the activity (mainly, within the norm) of DSEs, specific for the organs and tissues functioning of which is stressed in the period of post-flight readaptation (skeletal muscles, myocardium, liver). After the superlong missions, the DSE activity either remained essentially unchanged or decreased. In all the tested groups, highly reliable correlations between POL, SAP, and the DSE activity, traditionally applied in clinical diagnostics, were observed. These advocate for the use of POL and SAP indices in medical diagnostics and prognosis of cosmonauts' health.

Acid Phosphatase↗
PubMed1997

[Metabolism, intensity of lipid peroxidation and the antioxidant defense system in humans during chamber experiments with long-term isolation].

Blood biochemical parameters of lipid, protein, carbohydrate and energy metabolism were measured in a 135-day chamber experiment. Also, dynamics of the intensity of lipid peroxidation and status of the antioxidant defence system were evaluated. Results of the investigation showed that extended chamber isolation led to modifications of several biochemical parameters including hemoglobin, bilirubin, cholesterol and its fractions, elevated transaminase activity which are typical for long-term space mission. However, these were not accompanied by substantive changes in protein, energy and carbohydrate metabolisms, or intensity of free radical processes. Effects of prolonged stay in chamber was successfully counterbalanced by organism.

Adult↗
PubMed1994

[Effects of a long-term space flight on human biochemical status].

Biochemical status of cosmonauts was examined during long (4-6 months) space flights. A Reflotron device and test strips with an active principle based on "dry chemistry" methods were used. Blood plasma samples were collected from the finger for later laboratory analyses. Parameters characterizing metabolic status and functions of various body systems and organs were tested in blood and plasma samples. Space flight was found associated with increased peripheral blood levels of glucose, cholesterol, triglycerides, urea, uric acid, lactate, total protein, lactate dehydrogenase and amylase activities. The detected shifts were reversible. A hypothesis on minimal levels of energy metabolism under conditions of weightlessness was confirmed by reduced malate dehydrogenase and creatine phosphokinase activities in the blood during the flights. No correlation between the detected shifts and space flight duration was revealed.

Blood↗
PubMedDate not supplied

[Toxicological and sanitary evaluation of air pollution by substances discharged during managing of urban dumping soil].

The paper presents the results of sanitary and hygienic investigations whose reason was the situation established with the removal of dumping earth in the dwelling area of Mitino Microdistrict 8 gamma. The removed dumping earth found to have formaldehyde, benzenes, acetaldehyde, phenols, aromatic hydro carbons, polyaromatic compounds was a source of bad smelling substances that had entered the ambient air. A special study of the earth showed that it might yield volatile and bad smelling compounds, such as organic sulfides, aldehydes, mercaptans, ketones, etc. Their harmful health effects (during operations and in the late period) seem to be unlikely. When such work is under way, it is necessary to inform the population about possible consequences.

Air Pollutants↗
PubMedDate not supplied

[Metabolism in cosmonauts: the results of biochemical research on the blood of the crew members of the 7 prime expeditions on the Mir orbital space complex].

The pre- and postflight biochemical analyses of the blood of 16 cosmonauts flown aboard Mir orbital station over 125-366 days revealed the changes in carbohydrate, lipid and protein metabolism being in line with the present-day ideas about the space flight effects on the human metabolism. A particular individual pattern of the responses and the absence of correlation with flight duration of space expeditions ranging from 4 months to a 1 year, are noted.

Blood↗
PubMedDate not supplied

[Lipid peroxidation and the system of antioxidant protection in rats following a 13-day space flight on the Kosmos-1887 biosatellite].

After a 13-day space mission, in the rats flown on Cosmos-1887 biosatellite the parameters of lipid peroxidation and antioxidant defense system--the contents of diene conjugates, malonic dialdehyde, Schiff bases, tocopherol, total antioxidant activity (in blood plasma only), antioxidant enzyme activity (in tissues only)--superoxide dismutase, catalase, glutathio peroxidase, glutathio reductase have been measured in the blood plasma, myocardium, skeletal muscles and liver. The liver level of diene conjugates, Schiff bases and tocopherol decreased, and an activity of superoxide dismutase and catalase increased. In the skeletal muscles there was an elevation of diene conjugate contents followed by the decreases in malonic dialdehyde and superoxide dismutase activity. In rat myocardium, superoxide dismutase activity and tocopherol levels increased significantly. In the blood plasma the levels of tocopherol, malonic dialdehyde and total antioxidant activity were elevated. It is concluded that the observed changes in lipid peroxidation developed probably in response to an effect of the last dynamic stage of space flight and during re-adapting to the Earth environments.

Animals↗
PubMedDate not supplied

[Characteristics of cosmonauts' metabolism after extended missions on the international space station].

In eight Russian members of the ISS crews 1 to 5 enzymes and some other metabolites were analyzed in blood in the pre- launch period, on the landing day, and on days 6-8 and 14-19 of recovery. Deviations in the biochemical parameters were typically within the physiological norm without clinical implications. Biochemical deviations on the landing day seemed to relate to metabolic shifts due to long-term microgravity and, on the other hand, were a reaction to acute gravitational stress on return to 1 g. Dynamics of a number of parameters was markedly different as compared with the data from cosmonauts who had made long missions to the Mir space station, but this can be attributed to different g-profiles during descent and blood sampling schedule. In two to three wks the parameters regained normal values suggesting that negative effects of readaptation to the Earth's gravity were fully remedied.

Adaptation, Physiological↗
PubMedDate not supplied

[Octafluoropropane inhalation toxicity].

Wistar rats were used to study inhalation toxicity of octafluoropropane (OFP, freon-218) at the following concentration: 300 g/m3 (4-hrs), 30 g/m3 (0.5 to 4 hrs), 3 g/m3 (8 hrs), and 0.3 g/m3 (16 hrs). According to the histological analysis, OFP at the concentrations of 300 and 30 g/m3 had a politrophic toxic effect. Target organs were the lung, trachea, bronchus, heart, kidney, and the adrenaL There were dystrophic and necrobiotic lesions in the upper airways epithelium. Subacute and chronic vesicular bronchiolitis developed on days 7 and 14, respectively. Visceral organs and brain were found plethoric and the lung was found hemorrhagic. Similar lesions were seen in the trachea, bronchus, lung, liver, spleen, kidney, adrenal, heart, and the brain. Lipid redistribution was observed in the adrenal cortex and vascular reactions of renal tissue with juxtamedullar blood shunting. Toxicity of small OFP concentrations (3 and 0.3 g/m3) was distinguished by an extended aftereffect, these concentrations did not cause visible pathomorphologic changes but gave rise to an extended pathologic process detectable by biochemistry. In all concentrations, OFP impacted erythrocyte metabolism changing the lipid composition of cell membrane and activating membrane-bound adenosinetriphos-phatases. The activities of hepatocyte and myocardiac cytoplasmatic enzymes were altered in blood plasma. Increased malonic dialdehyde in blood plasma and decreased cell antioxidant GSH in erythrocytes suggested exaggerated lipid peroxidation. These data point to the necessity of revising the existing limits for OFP concentrations in air of populated areas, working areas, and closed human environments.

Administration, Inhalation↗
PubMedDate not supplied

[Status of the lipid peroxidation system in the tissues of rats following a 7-day flight on the Kosmos-1667 biosatellite].

Rats flown for 7 days on Cosmos-1667 were for the first time used to measure antioxidative enzymes (superoxide dismutase, glutathione peroxidase, glutathione reductase, catalase), lipid peroxidation products (diene conjugates, malonic dialdehyde, Schiff bases) and tocopherol. Enhanced lipid peroxidation in the heart was completely compensated by activation of antioxidative enzymes. The content of all lipid peroxidation products measured in the liver increased; this was accompanied by a decrease of glutathione peroxidase and an increase of superoxide dismutase activities. It is suggested that lipid peroxidation was activated in response to altered gravity.

Animals↗