Disease relevance of Hypogravity

• The effect of microgravity on cellulose synthesis using the model system of Acetobacter xylinum was the subject of recent investigations using The National Aeronautics and Space Administration's Reduced Gravity Laboratory, a modified KC-135 aircraft designed to produce 20 sec of microgravity during the top of a parabolic dive [1].
• The approach was to augment the magnitude of the carotid hypertension (and the hindbody hypotension) when hypogravity was simulated by head-down tilt by mechanically occluding the terminal aorta and the inferior vena cava [2].
• METHODS AND RESULTS: Bacterial isolates, Stenotrophomonas paucimobilis and Acinetobacter radioresistens, originally recovered from the water supply aboard the International Space Station (ISS) were grown in nutrient broth under modelled reduced gravity [3].
• This supports the idea that the most probable cause for the decreased O2 cost with reduced gravity is less body weight carried [4].

High impact information on Hypogravity

• Since the gravitational acceleration on Mars is about one-third that on Earth, and since particle settling speeds scale with gravity, we propose that some (although perhaps not all) Martian geomorphological features attributed to liquid flows may in fact be associated with dry granular flows in the presence of reduced gravity [5].
• Exposure to both hyper- and hypogravity environments likely induces neurovegetative and/or stress effects that could account for Fos labeling in autonomic nuclei and in nervous structures involved in the hypothalamo-pituitary-adrenal axis [6].
• The necessary manipulations required to use the device were tested on the KC-135 aircraft during the reduced gravity segment of parabolic flight [7].
• Crystallization experiments with MB-1 have been carried out on the ground and in reduced gravity on board Columbia orbiter during mission STS-80 [8].
• Changes in the cytoskeletal structures of vimentin and tubulin observed in cells exposed to low gravity conditions may have influenced the correct signal transduction [9].

Biological context of Hypogravity

• We found no variations in the levels of metalloproteases and an increased synthesis of their inhibitors (TIMP), suggesting that hypogravity does not induce a pro-angiogenic phenotype [10].

Anatomical context of Hypogravity

• Significant variations in time in the effective plasma ET-1 levels in the superior and inferior cava vessel blood of animals maintained for 6 days in hypogravity with respect to controls were observed [11].
• Obtained results suggest that the effects of hypogravity on cultured human endothelial cells are, possibly, associated with protein kinase C and/or adenylate cyclase activity and are accompanied by noticeable functional cell changes [12].

Associations of Hypogravity with chemical compounds

• In the decade preceding Apollo missions to the Moon, extensive studies were conducted on human locomotion in reduced gravity [13].
• Space Station Freedom will provide the essential scientific and technological research in areas that require long exposures to reduced gravity conditions [14].
• Useful modifications of earlier methods included splitting of the platelet rich plasma into multiple aliquots to improve pelleting efficiency at low gravity forces, use of saved platelet poor plasma to flush out injection syringes, and prompt use of commercial Indium-111-oxine sources 3 to 5 minutes after mixing with Ringer's Citrate Dextrose [15].
• We report here the STARDUST experience, a recent collaborative effort that brings together a successful American program of microgravity experiments on particle formation aboard NASA KC-135 Reduced Gravity Research Aircraft and several Italian research groups with expertise in microgravity research and astrophysical dust formation [16].
• Undecalcified (n = 140) and decalcified (n = 11) bone fragments were treated with either collagenase (to remove collagen portion; undecalcified n = 64, decalcified n = 11) or EDTA (to remove mineral portion; n = 76) under the reduced gravity environment on US Space Shuttle mission STS-57 [17].

Gene context of Hypogravity

• Moreover, hypogravity potentiated the effect of inflammatory cytokines (TNF-alpha and IL-1) on ICAM-1 expression [18].
• No increase in E-selectin or VCAM-1 expression was observed in ECs exposed to hypogravity itself [18].
• Effect of hypogravity on human lymphocyte activation [19].
• It is estimated that a mission to Mars may require up to 300 days in a microgravity environment; in the case of an aborted mission, the astronauts may have to remain in reduced gravity for up to three years [20].

Analytical, diagnostic and therapeutic context of Hypogravity

• However, hypogravity reduced E-selectin and VCAM-1 expression in cell cultures activated by cytokines, more visible at their low (5-10 U/ml) concentrations [18].

References