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Research Containing: Microgravity

Evolution of Russian Microgravity Countermeasures

by on 22 August 2016in Biology & Biotechnology No comment

INTRODUCTION: Countermeasures to prevent or partially offset the negative physiologic changes that are caused by the effects of microgravity play an important role in supporting the performance of crewmembers in flight and their safe return to Earth. Research conducted in Russia on the orbital stations Salyut and Mir, as well as simulation experiments on the ground, have demonstrated that changes that occur during extended spaceflight in various physiologic systems can be prevented or significantly decreased by using countermeasures. Hardware and techniques used on the ISS have been substantially improved to reflect the experience of previous extended missions on Russian orbital stations. Countermeasures used during early ISS missions consisted of the U.S. treadmill (TVIS), cycle ergometer (capital VE, Cyrilliccapital BE, Cyrillic-3), a set of resistance bands, a postural muscle loading suit (Penguin-3), electrical stimulator (Tonus-3), compression thigh cuffs (Braslet-capital EM, Cyrillic), a lower body negative pressure (LBNP) suit (Chibis), a lower body g-loading suit (Kentavr), and water/salt supplements. These countermeasures are described in this article.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26630193

Transient gene and microRNA expression profile changes of confluent human fibroblast cells in spaceflight

by on 22 August 2016in Biology & Biotechnology No comment

Microgravity, or an altered gravity environment different from the 1 g of the Earth, has been shown to influence global gene expression patterns and protein levels in cultured cells. However, most of the reported studies that have been conducted in space or by using simulated microgravity on the ground have focused on the growth or differentiation of these cells. It has not been specifically addressed whether nonproliferating cultured cells will sense the presence of microgravity in space. In an experiment conducted onboard the International Space Station, confluent human fibroblast cells were fixed after being cultured in space for 3 and 14 d, respectively, to investigate changes in gene and microRNA (miRNA) expression profiles in these cells. Results of the experiment showed that on d 3, both the flown and ground cells were still proliferating slowly, as measured by the percentage of Ki-67(+) cells. Gene and miRNA expression data indicated activation of NF-kappaB and other growth-related pathways that involve hepatocyte growth factor and VEGF as well as the down-regulation of the Let-7 miRNA family. On d 14, when the cells were mostly nonproliferating, the gene and miRNA expression profile of the flight sample was indistinguishable from that of the ground sample. Comparison of gene and miRNA expressions in the d 3 samples, with respect to d 14, revealed that most of the changes observed on d 3 were related to cell growth for both the flown and ground cells. Analysis of cytoskeletal changes via immunohistochemistry staining of the cells with antibodies for alpha-tubulin and fibronectin showed no difference between the flown and ground samples. Taken together, our study suggests that in true nondividing human fibroblast cells in culture, microgravity experienced in space has little effect on gene and miRNA expression profiles.-Zhang, Y., Lu, T., Wong, M., Wang, X., Stodieck, L., Karouia, F., Story, M., Wu, H. Transient gene and microRNA expression profile changes of confluent human fibroblast cells in spaceflight.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26917741

Comprehensive Study of the Influence of Altered Gravity on the Oxidative Burst of Mussel (Mytilus edulis) Hemocytes

by on 22 August 2016in Biology & Biotechnology No comment

Microgravity induces alterations in the function- ing of immune cell; however, the underlying mechanisms have not yet been identified. In this study, hemocytes (blood cells) of the blue mussel Mytilus edulis were investigated under altered gravity conditions. The study was conducted on the ground in preparation for the BIOLAB TripleLux- B experiment, which will be performed on the International Space Station (ISS). On-line kinetic measurements of reac- tive oxygen species (ROS) production during the oxidative burst and thus cellular activity of isolated hemocytes were performed in a photomultiplier (PMT)-clinostat (simulated microgravity) and in the 1g operation mode of the clino- stat in hypergravity on the Short-Arm Human Centrifuge (SAHC) as well as during parabolic flights. In addition to studies with isolated hemocytes, the effect of altered gravity conditions on whole animals was investigated. For this pur- pose, whole mussels were exposed to hypergravity (1.8 g) on a multi-sample incubator centrifuge (MuSIC) or to simu- lated microgravity in a submersed clinostat. After exposure for 48 h, hemocytes were taken from the mussels and ROS production was measured under 1 g conditions. The results from the parabolic flights and clinostat studies indicate that mussel hemocytes respond to altered gravity in a fast and reversible manner. Hemocytes (after cryo-conservation)exposed to simulated microgravity (μ g), as well as fresh hemocytes from clinorotated animals, showed a decrease in ROS production. Measurements during a permanent exposure of hemocytes to hypergravity (SAHC) show a decrease in ROS production. Hemocytes of mussels mea- sured after the centrifugation of whole mussels did not show an influence to the ROS response at all. Hypergravity dur- ing parabolic flights led to a decrease but also to an increase in ROS production in isolated hemocytes, whereas the cen- trifugation of whole mussels did not influence the ROS response at all. This study is a good example how ground- based facility experiments can be used to prepare for an upcoming ISS experiment, in this case the TRIPLE LUX B experiment.

Related URLs:
http://link.springer.com/article/10.1007/s12217-015-9438-9

ELITE S2 – AN INSTRUMENT FOR MOTION ANALYSIS ON BOARD THE INTERNATIONAL SPACE STATION

by on 22 August 2016in Biology & Biotechnology, Technology Development & Demonstration No comment

This paper describes the activities for utilization and control of ELITE S2 on board the International Space Station (ISS). ELITE S2 is a payload of the Italian Space Agency (ASI) for quantitative human movement analysis in weightlessness. Within the frame of a bilateral agreement with NASA, ASI has funded a number of facilities, enabling different scientific experiments on board the ISS. ELITE S2 has been developed by the ASI contractor Kayser Italia, delivered to the Kennedy Space Center in 2006 for pre-flight processing, launched in 2007 by the Space Shuttle Endeavour (STS-118), integrated in the U.S. lab and used during the Increments 16 and 17 through 2008. The ELITE S2 flight segment comprises equipment mounted into an Express Rack and a number of stowed items to be deployed for experiment performance (video cameras and accessories). The ground segment consists in a User Support Operations Center (based at Kayser Italia) enabling real-time payload control and a number of User Home Bases (located at the ASI and PIs premises), for the scientific assessment of the experiment performance. Two scientific protocols on reaching and cognitive processing have been successfully performed in five sessions involving two ISS crewmembers: IMAGINE 2 and MOVE.

Related URLs:
https://www.researchgate.net/publication/287076067_Elite_S2-an_instrument_for_motion_analysis_on_board_the_International_Space_Station

Guidelines for Dual Energy X-Ray Absorptiometry Analysis of Trabecular Bone-Rich Regions in Mice: Improved Precision, Accuracy, and Sensitivity for Assessing Longitudinal Bone Changes

by on 22 August 2016in Biology & Biotechnology No comment

Trabecular bone is frequently studied in osteoporosis research because changes in trabecular bone are the most common cause of osteoporotic fractures. Dual energy X-ray absorptiometry (DXA) analysis specific to trabecular bone-rich regions is crucial to longitudinal osteoporosis research. The purpose of this study is to define a novel method for accurately analyzing trabecular bone-rich regions in mice via DXA. This method will be utilized to analyze scans obtained from the International Space Station in an upcoming study of microgravity-induced bone loss. Thirty 12-week-old BALB/c mice were studied. The novel method was developed by preanalyzing trabecular bone-rich sites in the distal femur, proximal tibia, and lumbar vertebrae via high-resolution X-ray imaging followed by DXA and micro-computed tomography (micro-CT) analyses. The key DXA steps described by the novel method were (1) proper mouse positioning, (2) region of interest (ROI) sizing, and (3) ROI positioning. The precision of the new method was assessed by reliability tests and a 14-week longitudinal study. The bone mineral content (BMC) data from DXA was then compared to the BMC data from micro-CT to assess accuracy. Bone mineral density (BMD) intra-class correlation coefficients of the new method ranging from 0.743 to 0.945 and Levene’s test showing that there was significantly lower variances of data generated by new method both verified its consistency. By new method, a Bland-Altman plot displayed good agreement between DXA BMC and micro-CT BMC for all sites and they were strongly correlated at the distal femur and proximal tibia (r=0.846, p<0.01; r=0.879, p<0.01, respectively). The results suggest that the novel method for site-specific analysis of trabecular bone-rich regions in mice via DXA yields more precise, accurate, and repeatable BMD measurements than the conventional method. Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26956416

Nutrition and Bone Health in Space

by on 22 August 2016in Biology & Biotechnology No comment

The effect of weightlessness on the human skeletal system is one of the greatest concerns in safely extending space missions [1–11]. The ability to understand and counteract weightlessness-induced bone mineral loss will be vital to crew health and safety during and after extended-duration space sta- tion and exploration missions [1–7]. Research on bone mineral loss during space flight has gone on for more than half a century, and recent studies have shown significant progress in developing coun- termeasures that have proved to be effective, including good nutrition and exercise. We review the history of this research here and provide a summary of recent and ongoing studies, including efforts to counteract bone and calcium loss resulting from weightlessness. Unfortunately, the most obvious nutritional countermeasure—providing excess calcium—does not protect against bone loss [12]. This result is likely related to the decreased calcium absorption observed in space flight and in ground-based models [13–16]. Phosphate supplementation was also ineffective at reducing calcium excretion [17]. Combination therapy with calcium and phosphorus was also unsuccessful at mitigating bone loss and hypercalciuria [18]. Other nutrients, specifically sodium, protein, potassium, vitamin K, and omega-3 fatty acids, have also been proposed and/or tested as bone loss countermeasures [19], and are discussed in more detail below.

Related URLs:
http://link.springer.com/chapter/10.1007%2F978-1-4939-2001-3_41#page-1

Bone metabolism and renal stone risk during International Space Station missions

by on 22 August 2016in Biology & Biotechnology No comment

Bone loss and renal stone risk are longstanding concerns for astronauts. Bone resorption brought on by spaceflight elevates urinary calcium and the risk of renal stone formation. Loss of bone calcium leads to concerns about fracture risk and increased long-term risk of osteoporosis. Bone metabolism involves many factors and is interconnected with muscle metabolism and diet. We report here bone biochemistry and renal stone risk data from astronauts on 4- to 6-month International Space Station missions. All had access to a type of resistive exercise countermeasure hardware, either the Advanced Resistance Exercise Device (ARED) or the Interim Resistance Exercise Device (iRED). A subset of the ARED group also tested the bisphosphonate alendronate as a potential anti-resorptive countermeasure (Bis+ARED). While some of the basic bone marker data have been published, we provide here a more comprehensive evaluation of bone biochemistry with a larger group of astronauts. Regardless of exercise, the risk of renal stone formation increased during spaceflight. A key factor in this increase was urine volume, which was lower during flight in all groups at all time points. Thus, the easiest way to mitigate renal stone risk is to increase fluid consumption. ARED use increased bone formation without changing bone resorption, and mitigated a drop in parathyroid hormone in iRED astronauts. Sclerostin, an osteocyte-derived negative regulator of bone formation, increased 10-15% in both groups of astronauts who used the ARED (p<0.06). IGF-1, which regulates bone growth and formation, increased during flight in all 3 groups (p<0.001). Our results are consistent with the growing body of literature showing that the hyper-resorptive state of bone that is brought on by spaceflight can be countered pharmacologically or mitigated through an exercise-induced increase in bone formation, with nutritional support. Key questions remain about the effect of exercise-induced alterations in bone metabolism on bone strength and fracture risk. Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26456109

Magnesium and Space Flight

by on 22 August 2016in Biology & Biotechnology No comment

Magnesium is an essential nutrient for muscle, cardiovascular, and bone health on Earth, and during space flight. We sought to evaluate magnesium status in 43 astronauts (34 male, 9 female; 47 +/- 5 years old, mean +/- SD) before, during, and after 4-6-month space missions. We also studied individuals participating in a ground analog of space flight (head-down-tilt bed rest; n = 27 (17 male, 10 female), 35 +/- 7 years old). We evaluated serum concentration and 24-h urinary excretion of magnesium, along with estimates of tissue magnesium status from sublingual cells. Serum magnesium increased late in flight, while urinary magnesium excretion was higher over the course of 180-day space missions. Urinary magnesium increased during flight but decreased significantly at landing. Neither serum nor urinary magnesium changed during bed rest. For flight and bed rest, significant correlations existed between the area under the curve of serum and urinary magnesium and the change in total body bone mineral content. Tissue magnesium concentration was unchanged after flight and bed rest. Increased excretion of magnesium is likely partially from bone and partially from diet, but importantly, it does not come at the expense of muscle tissue stores. While further study is needed to better understand the implications of these findings for longer space exploration missions, magnesium homeostasis and tissue status seem well maintained during 4-6-month space missions.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26670248

Effect of Microgravity on Synthesis of Nano Ceria

by on 22 August 2016in Physical Sciences No comment

Cerium oxide (CeO2) was prepared using a controlled-precipitation method under microgravity at the International Space Station (ISS). For comparison, ceria was also synthesized under normal-gravity conditions (referred as control). The Brunauer-Emmett-Teller (BET) surface area, pore volume and pore size analysis results indicated that the ceria particles grown in space had lower surface area and pore volume compared to the control samples. Furthermore, the space samples had a broader pore size distribution ranging from 30–600 Å, whereas the control samples consisted of pore sizes from 30–50 Å range. Structural information of the ceria particles were obtained using TEM and XRD. Based on the TEM images, it was confirmed that the space samples were predominantly nano-rods, on the other hand, only nano-polyhedra particles were seen in the control ceria samples. The average particle size was larger for ceria samples synthesized in space. XRD results showed higher crystallinity as well as larger mean crystal size for the space samples. The effect of sodium hydroxide concentration on synthesis of ceria was also examined using 1 M and 3 M solutions. It was found that the control samples, prepared in 1 M and 3 M sodium hydroxide solutions, did not show a significant difference between the two. However, when the ceria samples were prepared in a more basic medium (3 M) under microgravity, a decrease in the particle size of the nano-rods and appearances of nano-polyhedra and spheres were observed.

Related URLs:
http://www.mdpi.com/2073-4344/5/3/1306

Comprehensive analysis of the skin fungal microbiota of astronauts during a half-year stay at the International Space Station

by on 22 August 2016in Biology & Biotechnology No comment

The International Space Station (ISS) is a huge manned construct located approximately 400 km above the earth and is inhabited by astronauts performing space experiments. Because the station is within a closed microgravity environment, the astronauts are subject to consistent stress. This study analyzed the temporal changes in the skin fungal microbiota of 10 astronauts using pyrosequencing and quantitative PCR assay before, during, and after their stay in the ISS. Lipophilic skin fungi, Malassezia predominated most samples regardless of the collection period, body site (cheek or chest), or subject. During their stay in the ISS, the level of Malassezia colonization changed by 7.6- +/- 7.5-fold (mean +/- standard deviation) and 9.5- +/- 24.2-fold in cheek and chest samples, respectively. At the species level, M. restricta, M. globosa, and M. sympodialis were more abundant. In the chest samples, the ratio of M. restricta to all Malassezia species increased, whereas it did not change considerably in cheek samples. Fungal diversity was reduced, and the ratio of Malassezia to all fungal colonization increased during the astronauts’ stay at the ISS. The ascomycetous yeast Cyberlindnera jadinii was detected in abundance in the in-flight sample of 5 of the 10 astronauts. The microorganism may have incidentally adhered to the skin during the preflight period and persisted on the skin thereafter. This observation suggests the ability of a specific or uncommon microorganism to proliferate in a closed environment. Our study is the first to reveal temporal changes in the skin fungal microbiota of ISS astronauts. These findings will provide information useful for maintaining the health of astronauts staying in the space environment for long periods and for preventing infection due to the human skin microbiota.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26773135