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At least 1,621 records · Page 90Linked to original sources
PubMed2002

Experimental analysis of gravitational effects on amphibian gastrulation.

The effects of simulated microgravity on blastopore (Bp) formation were analysed in Xenopus laevis and Cynops pyrrhogaster embryos. Simulated microgravity produced by clinostat rotation shifted the Bp-forming region toward the vegetal pole, more markedly in Cynops embryos than in Xenopus embryos. The simulated microgravity induced aggregation of endoderm cells at the center of the embryo and separation between the endoderm and presumptive mesoderm (PM). These findings suggest that clinostat treatment disrupts cell-to-cell interaction between endoderm and PM by increasing the separation between them and, as a result, Bp formation may be shifted towards the vegetal pole.

Animals↗
PubMed1987

Erythrocytes sedimentation profiles under gravitational field as determined by He-Ne laser. VII. Influence of dextrans, albumin and saline on cellular aggregation and sedimentation rate.

The erythrocytes sedimentation profiles (ESP) of normal blood and of blood mixed with saline, albumin (7%), and various molecular weight dextrans of different concentrations, at various height and widths of the sample holder are determined. These observations show that the sedimentation characteristics of the erythrocytes depend on the influence of these substitutes on the plasma and cellular constituents. The normalised aggregation and the sedimentation rate, as determined from these profiles, show that the dextran 40 and dextran 70 retard the erythrocytes sedimentation, for high molecular weight it is similar to that of normal blood and is the maximum for saline. This change for high molecular weight dextrans could be attributed to the enhanced aggregation tendency of erythrocytes and for saline to the enhanced sedimentation due to decrease in the viscosity and density of suspending medium. The influence of the various concentrations of dextrans on these parameters has been determined.

Albumins↗
PubMed1998

[The use of gravitational surgery of the blood. Plasmapheresis in the treatment of bronchial asthma patients].

It was noted while examination of 290 patients with chronic bronchial asthma (BA) that application of plasmapheresis (PA), contrary to hemosorption (HS), permits to achieve more rapid, but less durable remission. The conducted HS, contrary to PA, permits to normalize the common immunoglobulin E level in the blood serum. The advantages of the HS application in patients with atopic form of BA were established.

Administration, Inhalation↗
PubMed1993

Space Station Freedom: a unique laboratory for gravitational biology research.

The advent of Space Station Freedom (SSF) will provide a permanent laboratory in space with unparalleled opportunities to perform biological research. As with any spacecraft there will also be limitations. It is our intent to describe this space laboratory and present a picture of how scientists will conduct research in this unique environment we call space. SSF is an international venture which will continue to serve as a model for other peaceful international efforts. It is hoped that as the human race moves out from this planet back to the moon and then on to Mars that SSF can serve as a successful example of how things can and should be done.

Centrifugation↗
PubMed1995

Mechanical and electrical adaptation of skeletal muscle to gravitational unloading.

The physiological and biochemical properties of limb skeletal muscle have been shown to adapt to variety of experimental conditions. Among these is the microgravity encountered with spaceflight. It is adaptations accompanying skeletal muscle disuse atrophy. Foremost among these changes is a reduction in the force-generating capacity, which is presumably a direct result of decrease in fiber number and diameter. These changes suggest a spaceflight-induced reduction in muscle work capacity. The interesting finding that the reduction of the mechanical tension is not proportional to the reduction of muscle weight, fiber diameter, and concentration of contractile protein suggested that changes of electrical activity might contribute to the reduction of the contraction force in disused muscle. The purpose of our study was to assess the effects of a 7-d "dry" immersion on the contractile properties of the triceps surae muscle.

Action Potentials↗
PubMed1998

Gravitational biology on Mir.

The focus of this paper is to describe the experiences of a first time Space Life Sciences Principal Investigator. The Mir Beetle experiment was developed as a result of the joint US-Russian Mir Program. Dr. Alexei Alpatov collaborated as the Russian Co-Investigator. This experiment examined the long term effects of microgravity on the biological clock of a desert-dwelling beetle, Trigonoscelis gigas. The performance of this Space Life Sciences investigation involved: developing the proposal, design and testing of the hardware and execution of the spaceflight experiment.

Animals↗