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Biomedical subjects

A Kotovskaya

Publications and source records attributed to A Kotovskaya.

11 recordsLinked to original sources
PubMed2004

Changes in hemodynamic and post-flights orthostatic tolerance of cosmonauts under application of the preventive device--thigh cuffs bracelets in short-term flights.

SPECIFIC AIMS: to evaluate the influence of the use thigh cuffs "Bracelet" on the hemodynamic adaptation to microgravity during short-term (up to a month) space flights, in-flight tolerance to LBNP-tests and post-flight orthostatic tolerance. 6 cosmonauts applied and 7 others did not apply the occlusive cuffs when on flight. The "Bracelet" device notably relieved the cosmonauts from the subjective discomfort following by the blood redistribution at initial period of exposure to microgravity. It was established that "Bracelet" lessened shifts in central and peripheral hemodynamics typical for exposure to microgravity, venous stasis in the cervical-cephalic region in particular. There were no differences between the hemodynamic reaction on LBNP-test in cosmonauts who applied and not applied "Bracelet" during short-term flights. The objective data are received, that the application of the device during short-term space flight does not make negative effects on post-flight orthostatic tolerance.

Adaptation, Physiological↗
PubMed2000

Cardiac, arterial and venous adaptation to weightlessness during 6-month MIR spaceflights with and without thigh cuffs (bracelets).

The objectives of this investigation were to study the effects of thigh cuffs (bracelets) on cardiovascular adaptation and deconditioning in 0 g. The cardiovascular parameters of six cosmonauts were measured by echocardiography, Doppler, and plethysmography, during three 6-month MIR spaceflights. Measurements were made at rest during preflight (-30 days), inflight (1, 3-4, and 5-5.5 months) without cuffs (morning) and after 5 h with cuffs, and during postflight (+3 and +7 days). Lower-body negative pressure (LBNP) measurements were performed 1 day after each resting session. Inflight values of left ventricle end-diastolic volume and stroke volume measured without the thigh cuffs (-8 to -24% and -10 to -16%, respectively, both P < 0.05) were lower than corresponding preflight values. The jugular and femoral vein cross-sectional areas (Ajv and Afv, respectively) were enlarged (Ajv: by 23-30%, P < 0.001; Afv: by 33-70% P < 0.01). The renal and femoral vascular resistances (Rra and Rfa, respectively) decreased (Rra: by -15 to -16%, P < 0.01; Rfa: by -5 to -11%, P < 0.01). Inflight, the thigh cuffs reduced the Ajv (by -12 to -20%, P < 0.02), but enlarged the Afv (Afv: by 9-20%, P < 0.02) and increased the vascular resistance (Rra: by 8-13%, P < 0.05; Rfa: by 10-16%, P < 0.01) compared to corresponding inflight, without-cuffs values. During LBNP (-45 mmHg, where 1 mmHg = 133.3 N/ m2), Rfa and the ratio between cerebral and femoral blood flow (Qca/Qfa) increased less inflight and postflight (+25% for Rfa and +30% for Qca/Qfa) than during preflight (60% for Rfa and 75% for Qca/Qfa, P < 0.01). This reduced vasoconstrictive response and less efficient flow redistribution toward the brain was associated with orthostatic intolerance during postflight stand tests in all of the cosmonauts. The calf circumference increased less inflight and postflight (6% P < 0.05) than preflight (9% P < 0.05). The vascular response to LBNP remained similarly altered throughout the flight. The thigh cuffs compensated partially for the cardiovascular changes induced by exposure to 0 g, but did not interfere with 0 g deconditioning.

Adaptation, Physiological↗
PubMedDate not supplied

PHYSIOLAB: a new laboratory for the study of the cardio-vascular system.

On the basis of the experience gained during the previous french-russian missions on board MIR about the adaptation processes of the cardio-vascular system, a new laboratory has been designed. The objective of this "PHYSIOLAB" is to have a better understanding of the mechanisms underlying the changes in the cardio-vascular system, with a special emphasis on the phenomenon of cardio-vascular deconditioning after landing. Beyond these scientific objectives, it is also intended to use PHYSIOLAB to help in the medical monitoring on-board MIR, during functional tests such as LBNP. PHYSIOLAB will be set up in MIR by the French cosmonaut during the next french-russian CASSIOPEE mission in 1996. Its architecture is based on a central unit, which controls the experimental protocols, records the results and provides an interface for transmission to the ground via telemetry. Different specific modules are used for the acquisition of various physiological parameters. This PHYSIOLAB under development for the CASSIOPEE mission should evolve towards a more ambitious laboratory, whose definition would take into account the results obtained with the first version of PHYSIOLAB. This "second generation" laboratory should be developed in the frame of wide International cooperation.

Aerospace Medicine↗
PubMedDate not supplied

Biomedical program of the ALTAIR french russian flight onboard the MIR station.

One year after the achievement of the 2 weeks ANTARES french-russian mission in the MIR station in July 1992, a 22 days ALTAIR mission with a french cosmonaut has been performed in July 1993, making use of the scientific payload remaining on board. Taking benefit of the analysis of the previous mission, the experimental protocols were adapted to refine scientific objectives and gave to the scientists the opportunity to enhance quantitatively and qualitatively their results. The french biomedical program, conducted in close scientific cooperation with IMBP and associated laboratories, was composed of 8 experiments out of which 2 were new with regards to the ANTARES program. In the field of cardio-vascular physiology and fluid regulation, the experiments: ORTHOSTATISME, DIURESE have been renewed and complemented by the TISSU experiment (proposed by a german scientist) and a real-time tele-assistance program using US echography technic and ground support from the french CADMOS support control center located in Toulouse. With respect to neurosciences objectives, to the experiments VIMINAL (cognitive processes) and ILLUSIONS (study of proprioceptives cues), was added the SYNERGIES experiment to analyse the postural adjustments during movement. The IMMUNOLOGIE experiment carried on and the radiobiological experiment BIODOSE ended. Adding the results of the 2 missions ANTARES and ALTAIR, and the data obtained in between onboard with russian cosmonauts, the scientists have received a wealth of physiological data and gained reproducibility and confidence in their results.

Adaptation, Physiological↗
PubMedDate not supplied

Blood volume regulating hormones, fluid and electrolyte modifications during 21 and 198-day space flights (Altair-MIR 1993).

During the Altair MIR '93 mission we studied several parameters involved in blood volume regulation. The experiment was done on two cosmonauts before (B-60, B-30), during (D6, D12, D18 for French and D7, D12, D17 for Russian) and after the flight (R+1, R+3 and R+7). Space flight durations were different for two cosmonauts: for the Russian the flight duration was 198 days and for the French 21 days. On board the MIR station only urinary (volume and electrolytes, atrial natriuretic peptide (ANP), cyclic guanosine monophosphate (cGMP) and catecholamines) and salivary (cGMP and cortisol) samples were collected, centrifuged and stored in freezer. Lithium was used as a tracer to know exactly the 24 h urine output (CNES urine collection Kit). Before and after flight, blood was drawn with an epicite needle and vacutainer system for hormonal assays (renin, antidiuretic hormone, cGMP, ANP and aldosterone) in two positions: after 30 min rest in upright seated position and after 90 min of supine position. Salivary samples were collected simultaneously. During flight a decrease of diuresis and ANP and an increase of osmolality were found. No modifications of hematocrit, but an increase of salivary cGMP and cortisol were also observed. The decrease of urinary ANP is in favor of hypovolemia as described in previous flights. The postflight examinations revealed changes in fluid-electrolyte metabolism which indicate a hypohydration status and a stimulation of hormonal system responsible for water and electrolyte retention in order to readapt to the normal gravity.

Aldosterone↗
PubMedDate not supplied

Cardiac and vascular adaptation to 0g with and without thigh cuffs (Antares 14 and Altair 21 day Mir spaceflights).

UNLABELLED: Cardiovascular adaptation was evaluated on 2 astronauts: one wearing thigh cuffs from flight day 1 to 8 (14d flight), the second without cuffs (21d flight). Ultrasound investigations were performed at rest and during LBNP. RESULTS: Without thigh cuffs the cardiovascular adaptation consists in (1) the development of a hypovolemia with an increase of the heart rate and the cardiac output, (2) the decrease of the vascular tone in the deep (mesenteric and splanchnic) and peripheral (Lower limbs) vascular areas. The use of thigh cuffs maintains the volemia and the cardiac output at the preflight level (without heart rate increase) and prevents the loss of vascular tone in the deep and peripheral areas. Moreover the adaptative process changes since the cuffs are removed and even the volemia seems to be unaffected at this stage the vascular tone decreases to a comparable extend as during the flight without cuffs. Nevertheless during the flight without cuffs or 3 days after removing the cuffs hemodynamic signs of decreased orthostatic tolerance are present during the inflight and the 3 days post flight LBNP. Presently the possible contribution of the thigh cuffs to the reduction of the vascular deconditioning has not been tested yet.

Adaptation, Physiological↗
PubMedDate not supplied

PHYSIOLAB: a cardiovascular laboratory.

PHYSIOLAB is a cardio-vascular laboratory designed by CNES in cooperation with IMBP, with double scientific and medical goals: -a better understanding of the basic mechanisms involved in blood pressure and heart rate regulation, in order to predict and control the phenomenon of cardio-vascular deconditionning. -a real-time monitoring of cosmonauts during functional tests. Launched to the MIR station in 1996, this laboratory was set up and used for the first time by Claudie Andre-Deshays during the French mission "Cassiopeia". The scientific program is performed pre, post and in-flight to study phenomena related to the transition to microgravity as well as the return to the earth conditions. Particular emphasis was placed on the development of the real-time telemetry to monitor LBNP test. This function was successful during the Cassiopeia mission, providing the medical team at TSOUP (MIR Control Center in Moscow) with efficient means to control the physiological state of the cosmonaut. Based on the results of this first mission, IMBP and CNES will go on using Physiolab with Russian crews. CNES will take advantage of the upcoming French missions on MIR to improve the system, and intends to develop a new laboratory for the International Space Station.

Aerospace Medicine↗