PubMed HealthSearch

SEARCH · PubMed Health

Results for “Space Flight”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

[Medical provisions for the immediate post-flight period following long space flights].

At the final stage of long-term space flights first aid should be rendered in a specific way in cases of critical situations. Resuscitation and anesthesiology measures should be applied, if necessary, after study of flight-induced changes in the vital organs and systems. The paper describes the most important factors that should determine the tactics of resuscitation-anesthesiology support of the immediate postflight stage, if theoretically feasible acute life-endangering states develop. It also presents substantiated correction of routine clinical protocols of resuscitation aid.

Anesthesia

Alteration in human mononuclear leucocytes following space flight.

Reduced in vitro mitogen-stimulated proliferative responses have routinely been observed from astronauts' mononuclear leucocytes following space flight. This study investigated the effect of space flight on subpopulations of peripheral blood mononuclear cells from 30 shuttle astronauts prior to launch, upon landing and 3 days after flight. The total number of peripheral blood leucocytes, granulocytes and monocytes were increased after space flight (5.7 +/- 0.2 versus 7.0 +/- 0.2; 3.1 +/- 0.1 versus 5.0 +/- 0.1; and 0.16 +/- 0.02 versus 0.25 +/- 0.28 x 10(3) cells/mm3, respectively) whereas lymphocytes were decreased (2.2 +/- 0.1 versus 1.7 +/- 0.1 x 10(3) cells/mm3). Flow cytometry analysis on Ficoll-Hypaque isolated mononuclear cells upon landing revealed significant decreases in T-inducer (CD4+, Leu-8+; 32 +/- 2 versus 23 +/- 2%) and T-cytotoxic lymphocytes (CD8+, CD11b-; 17 +/- 1 versus 12 +/- 1%), and increases in monocytes (CD14+; 13 +/- 1 versus 21 +/- 1%) compared to pre-flight and post-flight samples whereas B cells (CD19+), T-helper (CD4+, Leu-8-) and T-suppressor (CD8+, CD11b+) populations did not change. Additional phenotypic analysis of these mononuclear leucocytes from 10 crew members upon landing revealed a reduction in natural killer (NK) cells (CD16+ or CD56+; 9 +/- 1 versus 3 +/- 1%) and an increase in monocytes that were negative for insulin and insulin-like growth factor-1 (IGF-1) receptor expression. Flow cytometric analysis indicated these hormone receptor negative monocytes were smaller and less granular than receptor positive monocytes. Therefore, a novel population of monocytes may be released into the peripheral blood during the stress of space flight or upon landing. These findings may explain some of the diverse in vitro immunological and endocrine changes observed in crew members following space flight.

Adult

Development of metabolic shifts in structures of the spinal reflex arc in rats after space flight.

The stage of structures of the spinal reflex arc was studied by methods of quantitative cytochemistry in rats after orbital space flights lasting 19.5 and 22.5 days; the RNA and cytoplasmic protein content was determined in spinal motoneurons and sensory neurons of the spinal ganglia, the composition of soluble proteins of the gray and white matter of the spinal cord and spinal ganglia was determined; the lactate dehydrogenase (LD) isozyme spectrum also was investigated in the spinal ganglia and muscles of the hind limbs. A decrease in the content of cytoplasmic proteins in the spinal motoneurons and neurons of the spinal ganglia and a decrease in the content of water-soluble proteins in the gray and white matter of the spinal cord were found 5-11 h after space flight lasting 19.5 days and during the first day after a space flight lasting 22.5 days. Significant changes in the activity of isozyme fractions LD1 and LD2 were found in homogenates of the spinal ganglia. On the 1st and 2nd days after flight the LD isozyme spectrum of the soleus muscle changed from "cardiac" to "intermediate" type. The changes discovered were evidently the result of functional underactivity of the skeletal muscles under conditions of weightlessness. An increase in the RNA content in the sensory and motor neurons and an increase in the content of water-soluble proteins in the gray matter of the spinal cord were found 25-27 days after the end of the space flights, probably a manifestation of readaptation of the animals to terrestrial conditions.

Adaptation, Physiological

[Effect of factors imitating space flight conditions on human lipid metabolism].

Studies of the effects of space flight simulation factors on lipid metabolism showed that space diets developed for space flights of different duration (dehydrated foodstuffs alone or in combination with foods preserved by other methods) did not produce noticeable changes in lipid metabolism. Nevertheless, other factors, i.e. hypokinesia, intake of nerobol during hypokinesia, an altered work-rest cycle, an increased carbon monoxide concentration (up to 15 mg/m3) influenced lipid metabolism.

Adult

Effect of space flight factors on the mammal: experimental-morphological study.

On the basis of a morphological examination of 27 rats that made a space flight and were sacrificed on the 1st-2nd and 26-27th days postflight, it has been shown that the 22-d space flight has produced no significant changes in the structural organization of vital organs of the animals. However, a space flight exposure is not indifferent for animals and leads to the development of morphologically visible changes in individual organs and systems (musculo-skeletal system, hemopoietic organs, hypothalamic-pituitary-adrenal system, renal juxtaglomerular system). The detected changes are reversible, nonspecific, and develop in animals exposed to ground-based hypokinetic and other stress experiments.

Adrenal Glands

[Principles of the sanitary and housekeeping arrangements in space flight environments].

Significant changes in the functional state of crewmembers during prolonged space missions necessitate corrections to be made in the scope and methods of sanitation and housekeeping arrangements. Due to the fact that in space flight automicroflora representatives may acquire greater importance as possible pathogenic agents, procedures providing body cleanliness should include both physico-chemical exposures and direct skin microflora treatment. On the basis of pertinent investigations the authors have developed selection criteria and requirements for detergents and disinfectants that may be used in prolonged space flights.

Ecological Systems, Closed

[Antibodies to muscle fiber antigens in the cosmonauts after a space flight].

The study of serum samples, obtained from 15 cosmonauts before and after space flights, with the use of the indirect fluorescent method showed that in 7 cosmonauts antibodies to different elements of the human heart muscle appeared after flights. Strong and very strong luminescence of the elements of heart muscle tissue was detected in the cosmonauts after the third space flight. When studying the sera on sections of bovine heart muscle tissue, the reactions of the sera taken before and after flights were found to have no essential differences.

Animals

Effect of a 22-day space flight on the lymphoid organs of rats.

The effect of a 22-d space flight on the lymphoid organs of rats has been investigated. It has been shown that the flight leads to hypoplasia of lymphoid organs, the spleen and thymus weight decreasing very noticeably. Histological, morphometric, and cytological examinations have demonstrated that hypoplasia of the spleen occurs due to a reduction of the number of lymphocytes and erythroid cells and hypoplasia of the thymus and lymph nodes due to a decrease of the lymphocyte number. Changes found in the lymphoid organs of the flight rats are reversible and the structure of lymphoid organs recovers 27 d postflight. Pathogenetic mechanisms of the changes developing in lymphoid organs of rats under the influence of space flight are discussed. The animal data are compared with the results of postflight medical examinations of astronauts.

Animals

[Theoretical aspects of developing a system of medical control in space flights].

The paper presents theortical approaches to the medical control system in prolonged space flights. It classifies the most probable states in long-term weightlessness. The main symptoms of these states are described. On the basis of this classification methods and parameters to be used in diagnosis of symptoms that may occur in space flights are discussed.

Anemia

[Effect of a 22-day space flight on the lymphoid organs of rats].

The effect of a 22-day space flight on lymph organs of rats was studied. The exposure produced hypoplasia of lymph organs and reduced the weight of the spleen and the thymus to the greatest extent. It was shown histologically, morphometrically and cytologically that hypoplasia of the spleen was associated with the decreased number of lymphocytes and erythrocytes whereas hypoplasia of the thymus and lymph nodes was related to the diminished number of lymphocytes. Changes in the lymph organs of flight rats were reversible. The structure of lymph organs restored by the 27th postflight day. The paper discussed pathogenetic mechanisms of the changes in the lymph organs of rats due to space flight effects and compares the data with the postflight medical examination of cosmonauts.

Animals

[Changes in the lymphoid organs of rats during space flight].

The thymus, spleen and inguinal lymphatic nodes of rats flown for 19.5 and 22.5 days on board of the Earth artificial satellites Cosmos-605 and Cosmos-782 were examined histologically. It was shown that prolonged space flights brought about accidental involution of lymph organs due to a decrease of the lymphocytes amount. It is suggested that hypoplasia of lymph organs resulted from stress effects of space flight factors. The mass disintegration of lymphocytes and accumulation of nuclear detritus in the thymus as well as neutrophil infiltration of the spleen can be attributed to the acute stress of the reentry and weightlessness--1 g transition stages. It is emphasized that inhibition of erythroid hemopoiesis in the spleen cannot be ascribed to stress effects of space flight factors. Possible contribution of the changes found in lymph organs to the immunological state of the animal body is discussed.

Animals

[State of rat liver and spleen DNA after space flight on the "Cosmos-605" satellite].

The effect of space flight on the content of nucleic acids and the structure of DNA in the rat liver and spleen was studied. The 22-day exposure did not influence the DNA content in tissues, whereas the RNA content decreased by 14% and 19% in the liver and spleen, respectively. The flight did not induce changes like one-stranded or paired breakages in the DNA structure. Studies of the liver showed a minor trend towards a fall of elastic viscosity of the DNA supermolecular structure (difference between the flight and control rats was statistically insignificant). The above changes in the state of nucleic acids in the liver and spleen were transient.

Animals

[Effect of artificial gravitation on the skeletal musculature of rats during space flights].

Comparative morphological and histochemical investigation of the rat skeletal muscles after a 18.5 days flight in the space ship "Cosmos-936" under conditions of weightlessness and artificial gravitation created by means of a centrifuge has demonstrated that weightlessness creates muscular atrophy, with fibres of different types affected in different muscles. The greatest changes take place in the soleus muscle. Metabolic disorders in the muscular tissue are manifested as an excessive deposition of glycogen and an increased content of phospholipids in it. The artificial gravitation favourably affects the state of the skeletal musculature preventing the development of metabolic disorders, though it does not completely avert the appearance of atrophic processes in it.

Animals

[Effect of a 49-day space flight on immunological reactivity indices and on the blood protein makeup in the crew of Saliut-5].

The prolonged 49-day space flight resulted in a significant inhibition of immunological reactivity of the Salyut-5 crewmembers which involved a decline in bactericidal activity of the serum and lysozyme activity of the saliva, and a decrease in the content of immunoglobulins in the saliva and tonsillary lacunae. After the flight recovery of reduced immunoreactivity took a longer time than after shorter-term flights. The prolonged space mission led to an increase of most globulin fractions and a decrease of albumin in blood. With respect to globulin fractions, a predominant increase in the content of C3c and C4-factors of the complement and immunoglobulins G, A, M was noted. Blood proteins returned to normal within a long period of time.

Antigen-Antibody Reactions

Effect of dehydration on erythropoiesis in mice: relevance to the "anemia" of space flight.

Mice deprived of water for 24 h showed an increase in hematocrit and loss of body weight comparable to that seen in men during space flight. The increase in hematocrit was entirely due to a decrease in plasma volume and was associated with suppression of erythropoiesis, but with no significant change in the serum titer of a presumptive humoral regulator of erythropoiesis, Erythroid Stimulating Activity (ESA). Mice deprived of water for 24 h may be a useful model for the study of the early hematological effects of space flight. The suppression of erythropoiesis due to a relative erythrocytosis appears to be independent of ESA.

Animals

[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

[DNA content in the organs of animals in space flight on the Kosmos-690 satellite].

The DNA content in the liver, spleen and bone marrow of white rats exposed to a prolonged gamma-irradiation at a dose of 220 and 800 rad on the 10th day of the 20.5-day space flight and the ground-based synchronous experiment was measured. Space flight factors produced a modifying effect on the postradiation changes in the DNA content. This modifying influence was detected in all organs tested, although in a different degree, and involved an enhancement of the radiation effect which was associated with retardation of postradiation regenerative processes.

Animals

[Oxygenation of the frontal cerebral cortex in monkeys during a two-week space flight].

In monkeys (Macaca mulatta) during a two-week space flight and in a ground-based control experiment, with semi-closed platinum electrodes, partial oxygen pressure (pO2) was registered in the frontal cerebral cortex. It was shown that during the flight there is a marked increase of pO2 in the frontal cortex, reaching maximal values on days 5-8 (up to 203%) with a subsequent tendency to normalization by day 11. In the control experiment pO2 values in the cortical zone studied did not exceed the baseline level throughout the period of registration. Analysis of the curves of pO2 oscillations in the frequency range from 0.2 to 0.01 Hz in-flight revealed a shift of the oscillation power spectrum in the long-wave direction which was not seen in the control experiment and suggested a decreased rate of tissue metabolism. As a possible explanation for the noted effects of pO2 dynamics during weightlessness, a combination of a decreased metabolic rate in the brain segment under study with a disorder in the mechanism of regulation of local cerebral blood flow is suggested.

Animals