Alteration of renal function of rats following spaceflight

NASA Technical Reports Server (NTRS)

Wade, C. E.; Morey-Holton, E.

1998-01-01

Following spaceflight, changes in renal function of humans have been suggested. To assess the effects of readaptation on renal function, urine was collected from male rats ( approximately 245 g) over a 2-wk period following a 14-day spaceflight. Rats were assigned to three groups: flight animals (n = 6), flight controls (n = 6) housed in the flight cages on the ground, and vivarium controls (n = 5) housed in standard shoe box cages. Animals were placed into individual metabolic cages for urine collection. Urine output was significantly increased for 3 days following flight. Excretion rates of Na+ and K+ were increased, resulting in an increased osmotic excretion rate. Creatinine excretion rate increased over the first two postflight days. Glomerular filtration rate increased immediately following spaceflight without changes in plasma creatinine, Na+, K+, or osmolality. Increased excretion of solute was thus the result of increased delivery and a decreased percent reabsorption of the filtered load. Osmolal clearance was increased immediately postflight while free water clearance was decreased. In growing rats, the diuresis after short-duration spaceflight is the result of an increase in solute excretion with an accompanying reduction in free water clearance.

Post-Spaceflight (STS-135) Mouse Splenocytes Demonstrate Altered Activation Properties and Surface Molecule Expression

PubMed Central

Crucian, Brian; Sams, Clarence

2015-01-01

Alterations in immune function have been documented during or post-spaceflight and in ground based models of microgravity. Identification of immune parameters that are dysregulated during spaceflight is an important step in mitigating crew health risks during deep space missions. The in vitro analysis of leukocyte activity post-spaceflight in both human and animal species is primarily focused on lymphocytic function. This report completes a broader spectrum analysis of mouse lymphocyte and monocyte changes post 13 days orbital flight (mission STS-135). Analysis includes an examination in surface markers for cell activation, and antigen presentation and co-stimulatory molecules. Cytokine production was measured after stimulation with T-cell mitogen or TLR-2, TLR-4, or TLR-5 agonists. Splenocyte surface marker analysis immediate post-spaceflight and after in vitro culture demonstrated unique changes in phenotypic populations between the flight mice and matched treatment ground controls. Post-spaceflight splenocytes (flight splenocytes) had lower expression intensity of CD4+CD25+ and CD8+CD25+ cells, lower percentage of CD11c+MHC II+ cells, and higher percentage of CD11c+MHC I+ populations compared to ground controls. The flight splenocytes demonstrated an increase in phagocytic activity. Stimulation with ConA led to decrease in CD4+ population but increased CD4+CD25+ cells compared to ground controls. Culturing with TLR agonists led to a decrease in CD11c+ population in splenocytes isolated from flight mice compared to ground controls. Consequently, flight splenocytes with or without TLR-agonist stimulation showed a decrease in CD11c+MHC I+, CD11c+MHC II+, and CD11c+CD86+ cells compared to ground controls. Production of IFN-γ was decreased and IL-2 was increased from ConA stimulated flight splenocytes. This study demonstrated that expression of surface molecules can be affected by conditions of spaceflight and impaired responsiveness persists under culture

Reduced receptor aggregation and altered cytoskeleton in cultured myocytes after space-flight

NASA Technical Reports Server (NTRS)

Gruener, R.; Roberts, R.; Reitstetter, R.

1994-01-01

We carried out parallel experiments first on the slow clinostat and then in space-flight to examine the effects of altered gravity on the aggregation of the nicotinic acetylcholine receptors and the structure of the cytoskeleton in cultured Xenopus embryonic muscle cells. By examining the concordance between results from space flight and the clinostat, we tested whether the slow clinostat is a relevant simulation paradigm. Space-flown cells showed marked changes in the distribution and organization of actin filaments and had a reduced incidence of acetylcholine receptor aggregates at the site of contact with polystyrene beads. Similar effects were found after clinostat rotation. The sensitivity of synaptic receptor aggregation and cytoskeletal morphology suggests that in the microgravity of space cell behavior may be importantly altered.

The role of cytokines in immune changes induced by spaceflight

NASA Technical Reports Server (NTRS)

Sonnenfeld, G.; Miller, E. S.

1993-01-01

It has become apparent that spaceflight alters many immune responses. Among the regulatory components of the immune response that have been shown to be affected by spaceflight is the cytokine network. Spaceflight, as well as model systems of spaceflight, have been shown to affect the production and action of various cytokines including interferons, interleukins, colony stimulating factors, and tumor necrosis factors. These changes have been shown not to involve a general shutdown of the cytokine network but, rather, to involve selective alterations of specific cytokine functions by spaceflight. The full breadth of changes in cytokines induced by spaceflight, as well as mechanisms, duration, adaptation, reversibility, and significance to resistance to infection and neoplastic diseases, remains to be established.

Terrestrial Spaceflight Analogs: Antarctica

NASA Technical Reports Server (NTRS)

Crucian, Brian

2013-01-01

Alterations in immune cell distribution and function, circadian misalignment, stress and latent viral reactivation appear to persist during Antarctic winterover at Concordia Station. Some of these changes are similar to those observed in Astronauts, either during or immediately following spaceflight. Others are unique to the Concordia analog. Based on some initial immune data and environmental conditions, Concordia winterover may be an appropriate analog for some flight-associated immune system changes and mission stress effects. An ongoing smaller control study at Neumayer III will address the influence of the hypoxic variable. Changes were observed in the peripheral blood leukocyte distribution consistent with immune mobilization, and similar to those observed during spaceflight. Alterations in cytokine production profiles were observed during winterover that are distinct from those observed during spaceflight, but potentially consistent with those observed during persistent hypobaric hypoxia. The reactivation of latent herpesviruses was observed during overwinter/isolation, that is consistently associated with dysregulation in immune function.

Plasma Cytokine Concentrations Indicate In-vivo Hormonal Regulation of Immunity is Altered During Long-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Crician, Brian E.; Zwart, Sara R.; Mehta, Satish; Uchakin, Peter; Quiriarte, Heather A.; Pierson, Duane; Sams, Clarence F.; Smith, Scott M.

2013-01-01

Background: Aspects of immune system dysregulation associated with long-duration spaceflight have yet to be fully characterized, and may represent a clinical risk to crewmembers during deep space missions. Plasma cytokine concentration may serve as an indicator of in vivo physiological changes or immune system mobilization. Methods: The plasma concentrations of 22 cytokines were monitored in 28 astronauts during long-duration spaceflight onboard the International Space Station. Blood samples were collected three times before flight, 3-5 times during flight (depending on mission duration), at landing and 30 days post-landing. Analysis was performed by bead array immunoassay. Results: With few exceptions, minimal detectable mean plasma levels (<10 pg/ml) were observed at baseline (launch minus 180) for innate inflammatory cytokines or adaptive regulatory cytokines, however IL-1ra and several chemokines were constitutively present. An increase in the plasma concentration IL-8, IL-1ra, Tpo, CCL4, CXCL5, TNF(alpha), GM-CSF and VEGF was observed associated with spaceflight. Significant post-flight increases were observed for IL-6 and CCL2. No significant alterations were observed during or following spaceflight for adaptive/T-regulatory cytokines (IL-2, IFN(gamma), IL-17, IL4, IL-5, IL-10). Conclusions: This pattern of cytokine dysregulation suggests multiple physiological adaptations persist during flight, including inflammation, leukocyte recruitment, angiogenesis and thrombocyte regulation.

Genomic response of the nematode Caenorhabditis elegans to spaceflight

PubMed Central

Selch, Florian; Higashibata, Akira; Imamizo-Sato, Mari; Higashitani, Atsushi; Ishioka, Noriaki; Szewczyk, Nathaniel J.; Conley, Catharine A.

2008-01-01

On Earth, it is common to employ laboratory animals such as the nematode Caenorhabditis elegans to help understand human health concerns. Similar studies in Earth orbit should help understand and address the concerns associated with spaceflight. The “International Caenorhabditis elegans Experiment FIRST” (ICE FIRST), was carried out onboard the Dutch Taxiflight in April of 2004 by an international collaboration of laboratories in France, Canada, Japan and the United States. With the exception of a slight movement defect upon return to Earth, the result of altered muscle development, no significant abnormalities were detected in spaceflown C. elegans. Work from Japan revealed apoptosis proceeds normally and work from Canada revealed no significant increase in the rate of mutation. These results suggest that C. elegans can be used to study non-lethal responses to spaceflight and can possibly be developed as a biological sensor. To further our understanding of C. elegans response to spaceflight, we examined the gene transcription response to the 10 days in space using a near full genome microarray analysis. The transcriptional response is consistent with the observed normal developmental timing, apoptosis, DNA repair, and altered muscle development. The genes identified as altered in response to spaceflight are enriched for genes known to be regulated, in C. elegans, in response to altered environmental conditions (Insulin and TGF-β regulated). These results demonstrate C. elegans can be used to study the effects of altered gravity and suggest that C. elegans responds to spaceflight by altering the expression of at least some of the same metabolic genes that are altered in response to differing terrestrial environments. PMID:18392117

ARG1 Functions in the Physiological Adaptation of Undifferentiated Plant Cells to Spaceflight.

PubMed

Zupanska, Agata K; Schultz, Eric R; Yao, JiQiang; Sng, Natasha J; Zhou, Mingqi; Callaham, Jordan B; Ferl, Robert J; Paul, Anna-Lisa

2017-11-01

Scientific access to spaceflight and especially the International Space Station has revealed that physiological adaptation to spaceflight is accompanied or enabled by changes in gene expression that significantly alter the transcriptome of cells in spaceflight. A wide range of experiments have shown that plant physiological adaptation to spaceflight involves gene expression changes that alter cell wall and other metabolisms. However, while transcriptome profiling aptly illuminates changes in gene expression that accompany spaceflight adaptation, mutation analysis is required to illuminate key elements required for that adaptation. Here we report how transcriptome profiling was used to gain insight into the spaceflight adaptation role of Altered response to gravity 1 (Arg1), a gene known to affect gravity responses in plants on Earth. The study compared expression profiles of cultured lines of Arabidopsis thaliana derived from wild-type (WT) cultivar Col-0 to profiles from a knock-out line deficient in the gene encoding ARG1 (ARG1 KO), both on the ground and in space. The cell lines were launched on SpaceX CRS-2 as part of the Cellular Expression Logic (CEL) experiment of the BRIC-17 spaceflight mission. The cultured cell lines were grown within 60 mm Petri plates in Petri Dish Fixation Units (PDFUs) that were housed within the Biological Research In Canisters (BRIC) hardware. Spaceflight samples were fixed on orbit. Differentially expressed genes were identified between the two environments (spaceflight and comparable ground controls) and the two genotypes (WT and ARG1 KO). Each genotype engaged unique genes during physiological adaptation to the spaceflight environment, with little overlap. Most of the genes altered in expression in spaceflight in WT cells were found to be Arg1-dependent, suggesting a major role for that gene in the physiological adaptation of undifferentiated cells to spaceflight. Key Words: ARG1-Spaceflight-Gene expression

ARG1 Functions in the Physiological Adaptation of Undifferentiated Plant Cells to Spaceflight

NASA Astrophysics Data System (ADS)

Zupanska, Agata K.; Schultz, Eric R.; Yao, JiQiang; Sng, Natasha J.; Zhou, Mingqi; Callaham, Jordan B.; Ferl, Robert J.; Paul, Anna-Lisa

2017-11-01

Scientific access to spaceflight and especially the International Space Station has revealed that physiological adaptation to spaceflight is accompanied or enabled by changes in gene expression that significantly alter the transcriptome of cells in spaceflight. A wide range of experiments have shown that plant physiological adaptation to spaceflight involves gene expression changes that alter cell wall and other metabolisms. However, while transcriptome profiling aptly illuminates changes in gene expression that accompany spaceflight adaptation, mutation analysis is required to illuminate key elements required for that adaptation. Here we report how transcriptome profiling was used to gain insight into the spaceflight adaptation role of Altered response to gravity 1 (Arg1), a gene known to affect gravity responses in plants on Earth. The study compared expression profiles of cultured lines of Arabidopsis thaliana derived from wild-type (WT) cultivar Col-0 to profiles from a knock-out line deficient in the gene encoding ARG1 (ARG1 KO), both on the ground and in space. The cell lines were launched on SpaceX CRS-2 as part of the Cellular Expression Logic (CEL) experiment of the BRIC-17 spaceflight mission. The cultured cell lines were grown within 60 mm Petri plates in Petri Dish Fixation Units (PDFUs) that were housed within the Biological Research In Canisters (BRIC) hardware. Spaceflight samples were fixed on orbit. Differentially expressed genes were identified between the two environments (spaceflight and comparable ground controls) and the two genotypes (WT and ARG1 KO). Each genotype engaged unique genes during physiological adaptation to the spaceflight environment, with little overlap. Most of the genes altered in expression in spaceflight in WT cells were found to be Arg1-dependent, suggesting a major role for that gene in the physiological adaptation of undifferentiated cells to spaceflight.

Effects of Spaceflight on Venous and Arterial Compliance

NASA Technical Reports Server (NTRS)

Ribeiro, L. C.; Laurie, S. S.; Lee, S. M. C.; Macias, B. R.; Martin, D. S.; Ploutz-Snyder, R.; Stenger, M. B.; Platts, S. H.

2017-01-01

The visual impairment and intracranial pressure (VIIP) syndrome is a spaceflight-associated set of symptoms affecting more than 50% of American astronauts who have flown International Space Station (ISS) missions. VIIP is defined primarily by visual acuity deficits and anatomical changes to eye structures (e.g. optic disc edema, choroidal folds, and globe flattening) and is hypothesized to be related to elevated intracranial pressure secondary to a cephalad fluid shift. However, ocular symptoms have not been replicated in subjects completing prolonged bed rest, a well-accepted spaceflight analog. Altered vascular compliance along with spaceflight factors such as diet, radiation exposure, or environmental factors may cause alterations in the cardiovascular system that contribute to the manifestation of ocular changes. Loss of visual acuity could be a significant threat to crew health and performance during and after an exploration mission and may have implications for years post-flight. The overall objective of this project is to determine if spaceflight alters vascular compliance and whether such an adaptation is related to the incidence of VIIP. This objective will be met by completing three separate but related projects.

Spaceflight alters microtubules and increases apoptosis in human lymphocytes (Jurkat)

NASA Technical Reports Server (NTRS)

Lewis, M. L.; Reynolds, J. L.; Cubano, L. A.; Hatton, J. P.; Lawless, B. D.; Piepmeier, E. H.

1998-01-01

Alteration in cytoskeletal organization appears to underlie mechanisms of gravity sensitivity in space-flown cells. Human T lymphoblastoid cells (Jurkat) were flown on the Space Shuttle to test the hypothesis that growth responsiveness is associated with microtubule anomalies and mediated by apoptosis. Cell growth was stimulated in microgravity by increasing serum concentration. After 4 and 48 h, cells filtered from medium were fixed with formalin. Post-flight, confocal microscopy revealed diffuse, shortened microtubules extending from poorly defined microtubule organizing centers (MTOCs). In comparable ground controls, discrete microtubule filaments radiated from organized MTOCs and branched toward the cell membrane. At 4 h, 30% of flown, compared to 17% of ground, cells showed DNA condensation characteristic of apoptosis. Time-dependent increase of the apoptosis-associated Fas/ APO-1 protein in static flown, but not the in-flight 1 g centrifuged or ground controls, confirmed microgravity-associated apoptosis. By 48 h, ground cultures had increased by 40%. Flown populations did not increase, though some cells were cycling and actively metabolizing glucose. We conclude that cytoskeletal alteration, growth retardation, and metabolic changes in space-flown lymphocytes are concomitant with increased apoptosis and time-dependent elevation of Fas/APO-1 protein. We suggest that reduced growth response in lymphocytes during spaceflight is linked to apoptosis.

Simulation of Ophthalmic Alterations at the Arctic, Antarctica and the International Space Station for Long-Duration Spaceflight

NASA Astrophysics Data System (ADS)

De Morais Mendonca Teles, Antonio; Gonçalves, Cristiane

2016-07-01

Well, we propose a series of long-period medical simulations in scientific bases at the Arctic, at Antarctica and aboard the International Space Station (ISS), involving natural ophthalmic diseases such as radiation, solar and trauma retinopathy, keratoconus, cataract, glaucoma, etc., and ophthalmic alterations by accidental injuries. These natural diseases, without a previous diagnosis, specially those specific retinopathy, appear after 1 month to 1.5 year, in average. Such studies will be valuable for the human deep-space exploration because during long-duration spaceflight, such as staying at the ISS, a Moon base and a manned trip to planet Mars, requires several months within such environments, and during such periods ophthalmic diseases and accidents might eventually occur, which could seriously affect the 'round-the-clock' work schedule of the astronauts and the long-duration spaceflight manned program.

Risk of Cardiac Rhythm Problems During Spaceflight

NASA Technical Reports Server (NTRS)

Lee, Stuart M. C.; Stenger, Michael B.; Laurie, Steven S.; Macias, Brandon R.

2017-01-01

NASA has concerns regarding the incidence and clinical significance of cardiac arrhythmias that could occur during long-term exposure to the spaceflight environment, such as on the International Space Station (ISS) or during a prolonged (e.g., up to 3 years) sojourn to Mars or on the Moon. There have been some anecdotal reports and a few documented cases of cardiac arrhythmias in space, including one documented episode of non-sustained ventricular tachycardia. The potential catastrophic nature of a sudden cardiac death in the remote space environment has led to concerns from the early days of the space program that spaceflight might be arrhythmogenic. Indeed, there are known and well-defined changes in the cardiovascular system with spaceflight: a) plasma volume is reduced, b) left ventricular mass is decreased, and c) the autonomic nervous system adapts to the weightless environment. Combined, these physiologic adaptations suggest that changes in cardiac structure and neuro-humoral environment during spaceflight could alter electrical conduction, although the evidence supporting this contention consists mostly of minor changes in QT interval (the time between the start of the Q wave and the end of the T wave on an electrocardiogram tracing) in a small number of astronauts after long-duration spaceflight. Concurrent with efforts by NASA Medical Operations to refine and improve screening techniques relevant to arrhythmias and cardiovascular disease, as NASA enters the era of exploration-class missions it will be critical to determine with the highest degree of certainty whether spaceflight by itself alters cardiac structure and function sufficiently to increase the risk of arrhythmias.

Effects of spaceflight on murine skeletal muscle gene expression

PubMed Central

Allen, David L.; Bandstra, Eric R.; Harrison, Brooke C.; Thorng, Seiha; Stodieck, Louis S.; Kostenuik, Paul J.; Morony, Sean; Lacey, David L.; Hammond, Timothy G.; Leinwand, Leslie L.; Argraves, W. Scott; Bateman, Ted A.; Barth, Jeremy L.

2009-01-01

Spaceflight results in a number of adaptations to skeletal muscle, including atrophy and shifts toward faster muscle fiber types. To identify changes in gene expression that may underlie these adaptations, we used both microarray expression analysis and real-time polymerase chain reaction to quantify shifts in mRNA levels in the gastrocnemius from mice flown on the 11-day, 19-h STS-108 shuttle flight and from normal gravity controls. Spaceflight data also were compared with the ground-based unloading model of hindlimb suspension, with one group of pure suspension and one of suspension followed by 3.5 h of reloading to mimic the time between landing and euthanization of the spaceflight mice. Analysis of microarray data revealed that 272 mRNAs were significantly altered by spaceflight, the majority of which displayed similar responses to hindlimb suspension, whereas reloading tended to counteract these responses. Several mRNAs altered by spaceflight were associated with muscle growth, including the phosphatidylinositol 3-kinase regulatory subunit p85α, insulin response substrate-1, the forkhead box O1 transcription factor, and MAFbx/atrogin1. Moreover, myostatin mRNA expression tended to increase, whereas mRNA levels of the myostatin inhibitor FSTL3 tended to decrease, in response to spaceflight. In addition, mRNA levels of the slow oxidative fiber-associated transcriptional coactivator peroxisome proliferator-associated receptor (PPAR)-γ coactivator-1α and the transcription factor PPAR-α were significantly decreased in spaceflight gastrocnemius. Finally, spaceflight resulted in a significant decrease in levels of the microRNA miR-206. Together these data demonstrate that spaceflight induces significant changes in mRNA expression of genes associated with muscle growth and fiber type. PMID:19074574

Alteration of gene expression profiles in skeletal muscle of rats exposed to microgravity during a spaceflight

NASA Technical Reports Server (NTRS)

Taylor, Wayne E.; Bhasin, Shalender; Lalani, Rukhsana; Datta, Anuj; Gonzalez-Cadavid, Nestor F.

2002-01-01

To clarify the mechanism of skeletal muscle wasting during spaceflights, we investigated whether intramuscular gene expression profiles are affected, by using DNA microarray methods. Male rats sent on the 17-day NASA STS-90 Neurolab spaceflight were sacrificed 24 hours after return to earth (MG group). Ground control rats were maintained for 17 days in flight-simulated cages (CS group). Spaceflight induced a 19% and 23% loss of tibialis anterior and gastrocnemius muscle mass, respectively, as compared to ground controls. Muscle RNA was analyzed by the Clontech Atlas DNA expression array in four rats, with two MG/ CS pairs for the tibialis anterior, and one pair for the gastrocnemius. Alterations in gene expression were verified for selected genes by reverse-transcription PCR. In both muscles of MG rats, mRNAs for 12 genes were up-regulated by over 2-fold, and 38 were down-regulated compared to controls. There was inhibition of genes for cell proliferation and growth factor cascades, including cell cycle genes and signal transduction proteins, such as p21 Cip1, retinoblastoma (Rb), cyclins G1/S, -E and -D3, MAP kinase 3, MAD3, and ras related protein RAB2. These data indicate that following exposure to microgravity, there is downregulation of genes involved in regulation of muscle satellite cell replication.

Immune changes in test animals during spaceflight

NASA Technical Reports Server (NTRS)

Lesnyak, A. T.; Sonnenfeld, G.; Rykova, M. P.; Meshkov, D. O.; Mastro, A.; Konstantinova, I.

1993-01-01

Over the past two decades, it has become apparent that changes in immune parameters occur in cosmonauts and astronauts after spaceflight. Therefore, interest has been generated in the use of animal surrogates to better understand the nature and extent of these changes, the mechanism of these changes, and to allow the possible development of countermeasures. Among the changes noted in animals after spaceflight are alterations in lymphocytic blastogenesis, cytokine function, natural killer cell activity, and colony-stimulating factors. The nature and significance of spaceflight-induced changes in immune responses will be the focus of this review.

Long-Duration Spaceflight During the Bion-M1 Spaceflight Experiment Resulted in Significant Bone Loss in the Femoral Head and Alterations in Stem Cell Differentiation Potential in Male Mice

NASA Astrophysics Data System (ADS)

Blaber, Elizabeth; Almeida, Eduardo; Grigoryan, Eleonora; Globus, Ruth

Scientific understanding of the effects of microgravity on mammalian physiology has been limited to short duration spaceflight experiments (10-15 days). As long duration and inter-planetary missions are being initiated, there is a great need to understand the long-term effects of spaceflight on various physiological processes, including stem cell-based tissue regeneration. Bion-M1, for the first time, enabled the possibility of studying the effects of 30-days of microgravity exposure on a mouse model with sufficient sample size to enable statistical analysis. In this experiment, we hypothesized that microgravity negatively impacts stem cell based tissue regeneration, such as bone remodeling and regeneration from hematopoietic and mesenchymal precursors, thereby resulting in tissue degeneration in mice exposed to spaceflight. To test this hypothesis we collected the pelvis and proximal femur from space-flown mice and asynchronous ground controls and analyzed bone and bone marrow using techniques including Microcomputed Tomography (MicroCT), and in-vitro differentiation and differentiating cell motility assays. To determine the effects of 30-days spaceflight on bone tissue mass, we used MicroCT to analyze the trabecular bone of the femoral head and the cortical bone of the femoral neck and mid-shaft. We found that spaceflight caused a 45% decrease in bone volume ratio, a 17% decrease in trabecular thickness, a 25% decrease in trabecular number, and a 17% increase in trabecular spacing of trabecular bone. Furthermore, structural model index and trabecular pattern factor were increased by 32% and 82% respectively indicating that 30-days spaceflight resulted not only in a large loss of trabecular bone but also in a decrease of bone strength indicators. Analysis of the femoral neck cortical bone showed an increase in marrow area and cortical porosity indicating an overall widening of the femoral neck. Interestingly, no significant alterations were found in the cortical

The Effects of Spaceflight and a Spaceflight Analog on Neurocognitive Perfonnance: Extent, Longevity, and Neural Bases

NASA Technical Reports Server (NTRS)

Seidler, R. D.; Mulavara, A. P.; Koppelmans, V.; Erdeniz, B.; Kofman, I. S.; DeDios, Y. E.; Szecsy, D. L.; Riascos-Castaneda, R. F.; Wood, S. J.; Bloomberg, J. J.

2014-01-01

We are conducting ongoing experiments in which we are performing structural and functional magnetic resonance brain imaging to identify the relationships between changes in neurocognitive function and neural structural alterations following a six month International Space Station mission and following 70 days exposure to a spaceflight analog, head down tilt bedrest. Our central hypothesis is that measures of brain structure, function, and network integrity will change from pre to post intervention (spaceflight, bedrest). Moreover, we predict that these changes will correlate with indices of cognitive, sensory, and motor function in a neuroanatomically selective fashion. Our interdisciplinary approach utilizes cutting edge neuroimaging techniques and a broad ranging battery of sensory, motor, and cognitive assessments that will be conducted pre flight, during flight, and post flight to investigate potential neuroplastic and maladaptive brain changes in crewmembers following long-duration spaceflight. Success in this endeavor would 1) result in identification of the underlying neural mechanisms and operational risks of spaceflight-induced changes in behavior, and 2) identify whether a return to normative behavioral function following re-adaptation to Earth's gravitational environment is associated with a restitution of brain structure and function or instead is supported by substitution with compensatory brain processes. With the bedrest study, we will be able to determine the neural and neurocognitive effects of extended duration unloading, reduced sensory inputs, and increased cephalic fluid distribution. This will enable us to parse out the multiple mechanisms contributing to any spaceflight-induced neural structural and behavioral changes that we observe in the flight study. In this presentation I will discuss preliminary results from six participants who have undergone the bed rest protocol. These individuals show decrements in balance and functional mobility

Pharmacokinetic consequences of spaceflight

NASA Technical Reports Server (NTRS)

Putcha, L.; Cintron, N. M.

1991-01-01

Spaceflight induces a wide range of physiological and biochemical changes, including disruption of gastrointestinal (GI) function, fluid and electrolyte balance, circulatory dynamics, and organ blood flow, as well as hormonal and metabolic perturbations. Any of these changes can influence the pharmacokinetics and pharmacodynamics of in-flight medication. That spaceflight may alter bioavailability was proposed when drugs prescribed to alleviate space motion sickness (SMS) had little therapeutic effect. Characterization of the pharmacokinetic and/or pharmacodynamic behavior of operationally critical medications is crucial for their effective use in flight; as a first step, we sought to determine whether drugs administered in space actually reach the site of action at concentrations sufficient to elicit the therapeutic response.

Altered Innate and Lymphocytic Immunity in Murine Splenocytes Following Short-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Crucian, Brian E.; Hwang, Shen-An; Actor, Jeffrey K.; Quiriarte, Heather; Sams, Clarence F.

2011-01-01

Immune dysregulation has been demonstrated following spaceflight of varying durations and limited in-flight studies indicate this phenomenon may persist during spaceflight. Causes may include microgravity, physiological stress, isolation, confinement and disrupted circadian rhythms. To further investigate the mechanisms associated with flight-associated immune changes, murine splenocytes immune parameters were assessed following 14 day space flight on Space Shuttle mission STS-135.

Crewmember Performance Before, During, And After Spaceflight

PubMed Central

Kelly, Thomas H; Hienz, Robert D; Zarcone, Troy J; Wurster, Richard M; Brady, Joseph V

2005-01-01

The development of technologies for monitoring the welfare of crewmembers is a critical requirement for extended spaceflight. Behavior analytic methodologies provide a framework for studying the performance of individuals and groups, and brief computerized tests have been used successfully to examine the impairing effects of sleep, drug, and nutrition manipulations on human behavior. The purpose of the present study was to evaluate the feasibility and sensitivity of repeated performance testing during spaceflight. Four National Aeronautics and Space Administration crewmembers were trained to complete computerized questionnaires and performance tasks at repeated regular intervals before and after a 10-day shuttle mission and at times that interfered minimally with other mission activities during spaceflight. Two types of performance, Digit-Symbol Substitution trial completion rates and response times during the most complex Number Recognition trials, were altered slightly during spaceflight. All other dimensions of the performance tasks remained essentially unchanged over the course of the study. Verbal ratings of Fatigue increased slightly during spaceflight and decreased during the postflight test sessions. Arousal ratings increased during spaceflight and decreased postflight. No other consistent changes in rating-scale measures were observed over the course of the study. Crewmembers completed all mission requirements in an efficient manner with no indication of clinically significant behavioral impairment during the 10-day spaceflight. These results support the feasibility and utility of computerized task performances and questionnaire rating scales for repeated measurement of behavior during spaceflight. PMID:16262187

Spaceflight Activates Lipotoxic Pathways in Mouse Liver

PubMed Central

Jonscher, Karen R.; Alfonso-Garcia, Alba; Suhalim, Jeffrey L.; Orlicky, David J.; Potma, Eric O.; Ferguson, Virginia L.; Bouxsein, Mary L.; Bateman, Ted A.; Stodieck, Louis S.; Levi, Moshe; Friedman, Jacob E.; Gridley, Daila S.; Pecaut, Michael J.

2016-01-01

Spaceflight affects numerous organ systems in the body, leading to metabolic dysfunction that may have long-term consequences. Microgravity-induced alterations in liver metabolism, particularly with respect to lipids, remain largely unexplored. Here we utilize a novel systems biology approach, combining metabolomics and transcriptomics with advanced Raman microscopy, to investigate altered hepatic lipid metabolism in mice following short duration spaceflight. Mice flown aboard Space Transportation System -135, the last Shuttle mission, lose weight but redistribute lipids, particularly to the liver. Intriguingly, spaceflight mice lose retinol from lipid droplets. Both mRNA and metabolite changes suggest the retinol loss is linked to activation of PPARα-mediated pathways and potentially to hepatic stellate cell activation, both of which may be coincident with increased bile acids and early signs of liver injury. Although the 13-day flight duration is too short for frank fibrosis to develop, the retinol loss plus changes in markers of extracellular matrix remodeling raise the concern that longer duration exposure to the space environment may result in progressive liver damage, increasing the risk for nonalcoholic fatty liver disease. PMID:27097220

Efficacy of Antimicrobials on Bacteria Cultured in a Spaceflight Analogue

NASA Technical Reports Server (NTRS)

Nickerson, CA; Wotring, Virginia; Barrila, Jennifer; Crabbe, Aurelie; Castro, Sarah; Davis, Richard; Rideout, April; McCarthy, Breanne; Ott, C. Mark

2014-01-01

As humans travel in space, they will interact with microbial flora from themselves, other crewmembers, their food, and the environment. While evaluations of microbial ecology aboard the Mir and ISS suggest a predominance of common environmental flora, the presence of (and potential for) infectious agents has been well documented. Likewise, pathogens have been detected during preflight monitoring of spaceflight food, resulting in the disqualification of that production lot from flight. These environmental and food organisms range from the obligate pathogen, Salmonella enterica serovar Typhimurium (S. Typhimurium), which has been responsible for disqualification and removal of food destined for ISS and has previously been reported from Shuttle crew refuse, to the opportunistic pathogen Staphylococcus aureus, isolated numerous times from ISS habitable compartments and the crew. Infectious disease events have affected spaceflight missions, including an upper respiratory infection that delayed the launch of STS-36 and an incapacitating Pseudomonas aeruginosa urinary tract infection of a crewmember during Apollo 13. These observations indicate that the crew has the potential to be exposed to obligate and opportunistic pathogens. This risk of exposure is expected to increase with longer mission durations and increased use of regenerative life support systems. As antibiotics are the primary countermeasure after infection, determining if their efficacy during spaceflight missions is comparable to terrestrial application is of critical importance. The NASA Rotating Wall Vessel (RWV) culture system has been successfully used as a spaceflight culture analogue to identify potential alterations in several key microbial characteristics, such as virulence and gene regulation, in response to spaceflight culture. We hypothesized that bacteria cultured in the low fluid shear RWV environment would demonstrate changes in efficacy of antibiotics compared to higher fluid shear controls

Genetic dissection of the Arabidopsis spaceflight transcriptome: Are some responses dispensable for the physiological adaptation of plants to spaceflight?

PubMed Central

Sng, Natasha J.; Zupanska, Agata K.; Krishnamurthy, Aparna; Schultz, Eric R.; Ferl, Robert J.

2017-01-01

Experimentation on the International Space Station has reached the stage where repeated and nuanced transcriptome studies are beginning to illuminate the structural and metabolic differences between plants grown in space compared to plants on the Earth. Genes that are important in establishing the spaceflight responses are being identified, their roles in spaceflight physiological adaptation are increasingly understood, and the fact that different genotypes adapt differently is recognized. However, the basic question of whether these spaceflight responses are actually required for survival has yet to be posed, and the fundamental notion that spaceflight responses may be non-adaptive has yet to be explored. Therefore the experiments presented here were designed to ask if portions of the plant spaceflight response can be genetically removed without causing loss of spaceflight survival and without causing increased stress responses. The CARA experiment compared the spaceflight transcriptome responses in the root tips of two Arabidopsis ecotypes, Col-0 and WS, as well as that of a PhyD mutant of Col-0. When grown with the ambient light of the ISS, phyD plants displayed a significantly reduced spaceflight transcriptome response compared to Col-0, suggesting that altering the activity of a single gene can actually improve spaceflight adaptation by reducing the transcriptome cost of physiological adaptation. The WS genotype showed an even simpler spaceflight transcriptome response in the ambient light of the ISS, more broadly indicating that the plant genotype can be manipulated to reduce the cost of spaceflight adaptation, as measured by transcriptional response. These differential genotypic responses suggest that genetic manipulation could further reduce, or perhaps eliminate the metabolic cost of spaceflight adaptation. When plants were germinated and then left in the dark on the ISS, the WS genotype actually mounted a larger transcriptome response than Col-0

Genetic dissection of the Arabidopsis spaceflight transcriptome: Are some responses dispensable for the physiological adaptation of plants to spaceflight?

PubMed

Paul, Anna-Lisa; Sng, Natasha J; Zupanska, Agata K; Krishnamurthy, Aparna; Schultz, Eric R; Ferl, Robert J

2017-01-01

Experimentation on the International Space Station has reached the stage where repeated and nuanced transcriptome studies are beginning to illuminate the structural and metabolic differences between plants grown in space compared to plants on the Earth. Genes that are important in establishing the spaceflight responses are being identified, their roles in spaceflight physiological adaptation are increasingly understood, and the fact that different genotypes adapt differently is recognized. However, the basic question of whether these spaceflight responses are actually required for survival has yet to be posed, and the fundamental notion that spaceflight responses may be non-adaptive has yet to be explored. Therefore the experiments presented here were designed to ask if portions of the plant spaceflight response can be genetically removed without causing loss of spaceflight survival and without causing increased stress responses. The CARA experiment compared the spaceflight transcriptome responses in the root tips of two Arabidopsis ecotypes, Col-0 and WS, as well as that of a PhyD mutant of Col-0. When grown with the ambient light of the ISS, phyD plants displayed a significantly reduced spaceflight transcriptome response compared to Col-0, suggesting that altering the activity of a single gene can actually improve spaceflight adaptation by reducing the transcriptome cost of physiological adaptation. The WS genotype showed an even simpler spaceflight transcriptome response in the ambient light of the ISS, more broadly indicating that the plant genotype can be manipulated to reduce the cost of spaceflight adaptation, as measured by transcriptional response. These differential genotypic responses suggest that genetic manipulation could further reduce, or perhaps eliminate the metabolic cost of spaceflight adaptation. When plants were germinated and then left in the dark on the ISS, the WS genotype actually mounted a larger transcriptome response than Col-0

Response of Staphylococcus Aureus to a Spaceflight Analogue

NASA Technical Reports Server (NTRS)

Castro, S. L.; Ott, C. M.

2010-01-01

The decreased gravity of the spaceflight environment creates quiescent, low fluid shear conditions. This environment can impart considerable effects on the physiology of microorganisms as well as their interactions with potential hosts. Using the rotating wall vessel (RWV), as a spaceflight analogue, the consequence of low fluid shear culture on microbial pathogenesis has provided a better understanding of the risks to the astronaut crew from infectious microorganisms. While the outcome of low fluid shear culture has been investigated for several bacterial pathogens, little has been done to understand how this environmental factor affects Staphylococcus aureus. S. aureus is an opportunistic human pathogen which presents a high level of infection risk to the crew, as it has been isolated from both the space shuttle and International Space Station. Given that approximately forty percent of the population are carriers of the bacteria, eradication of this organism from in flight environments is impractical. These reasons have lead to us to assess the response of S. aureus to a reduced fluid shear environment. Culture in the RWV demonstrated that S. aureus grown under the low-shear condition had lower cell concentrations after 10 hours when compared to the control culture. Furthermore, the low-shear cultured bacteria displayed a reduction in carotenoid production, pigments responsible for their yellow/gold coloration. When exposed to various environmental stressors, post low-shear culture, a decrease in the ability to survive oxidative assault was observed compared to control cultures. The low fluid shear environment also resulted in a decrease in hemolysin secretion, a staphylococcal toxin responsible for red blood cell lysis. When challenged by the immune components present in human whole blood, low-shear cultured S. aureus demonstrated significantly reduced survival rates as compared to the control culture. Assays to determine the duration of these alterations

Auditory and Vestibular Issues Related to Human Spaceflight

NASA Technical Reports Server (NTRS)

Danielson, Richard W.; Wood, Scott J.

2009-01-01

Human spaceflight provides unique opportunities to study human vestibular and auditory systems. This session will discuss 1) vestibular adaptive processes reflected by pronounced perceptual and motor coordination problems during, and after, space missions; 2) vestibular diagnostic and rehabilitative techniques (used to promote recovery after living in altered gravity environments) that may be relevant to treatment of vestibular disorders on earth; and 3) unique acoustical challenges to hearing loss prevention and crew performance during spaceflight missions.

Microbiological concerns and methodological approaches related to bacterial water quality in spaceflight

NASA Technical Reports Server (NTRS)

Pyle, Barry H.; Mcfeters, Gordon A.

1992-01-01

A number of microbiological issues are of critical importance to crew health and system performance in spacecraft water systems. This presentation reviews an army of these concerns which include factors that influence water treatment and disinfection in spaceflight such as biofilm formation and the physiological responses of bacteria in clean water systems. Factors associated with spaceflight like aerosol formation under conditions of microgravity are also discussed within the context of airborne infections such as Legionellosis. Finally, a spectrum of analytical approaches is reviewed to provide an evaluation of methodological alternatives that have been suggested or used to detect microorganisms of interest in water systems. These range from classical approaches employing colony formation on specific microbiological growth media to direct (i.e. microscopic) and indirect (e.g. electrochemical) methods as well as the use of molecular approaches and gene probes. These techniques are critically evaluated for their potential utility in determining microbiological water quality through the detection of microorganisms under the influence of ambient environmental stress inherent in spaceflight water systems.

Altered skeletal pattern of gene expression in response to spaceflight and hindlimb elevation

NASA Technical Reports Server (NTRS)

Bikle, D. D.; Harris, J.; Halloran, B. P.; Morey-Holton, E.

1994-01-01

Spaceflight leads to osteopenia, in part by inhibiting bone formation. Using an animal model (hindlimb elevation) that simulates the weightlessness of spaceflight, we and others showed a reversible inhibition of bone formation and bone mineralization. In this study, we have measured the mRNA levels of insulin-like growth factor I (IGF-I), IGF-I receptor (IGF-IR), alkaline phosphatase, and osteocalcin in the tibiae of rats flown aboard National Aeronautics and Space Administration Shuttle Flight STS-54 and compared the results with those obtained from their ground-based controls and from the bones of hindlimb-elevated animals. Spaceflight and hindlimb elevation transiently increase the mRNA levels for IGF-I, IGF-IR, and alkaline phosphatase but decrease the mRNA levels for osteocalcin. The changes in osteocalcin and alkaline phosphatase mRNA levels are consistent with a shift toward decreased maturation, whereas the rise in IGF-I and IGF-IR mRNA levels may indicate a compensatory response to the fall in bone formation. We conclude that skeletal unloading during spaceflight or hindlimb elevation resets the pattern of gene expression in the osteoblast, giving it a less mature profile.

Spaceflight alters immune cell function and distribution

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald; Mandel, Adrian D.; Konstantinova, Irina V.; Berry, Wallace D.; Taylor, Gerald R.; Lesniak, A. T.; Fuchs, Boris B.; Rakhmilevich, Alexander L.

1992-01-01

Experiments are described which were performed onboard Cosmos 2044 to determine spaceflight effects on immunologically important cell function and distribution. Results indicate that bone marrow cells from flown and suspended rats exhibited a decreased response to a granulocyte/monocyte colony-stimulating factor compared with the bone marrow cells from control rats. Bone marrow cells showed an increase in the percentage of cells expressing markers for helper T-cells in the myelogenous population and increased percentages of anti-asialo granulocyte/monocyte-1-bearing interleulin-2 receptor bearing pan T- and helper T-cells in the lymphocytic population.

Spaceflight on the Bion-M1 biosatellite alters cerebral artery vasomotor and mechanical properties in mice

PubMed Central

Sofronova, Svetlana I.; Tarasova, Olga S.; Gaynullina, Dina; Borzykh, Anna A.; Behnke, Bradley J.; Stabley, John N.; McCullough, Danielle J.; Maraj, Joshua J.; Hanna, Mina; Muller-Delp, Judy M.; Vinogradova, Olga L.

2015-01-01

Conditions during spaceflight, such as the loss of the head-to-foot gravity vector, are thought to potentially alter cerebral blood flow and vascular resistance. The purpose of the present study was to determine the effects of long-term spaceflight on the functional, mechanical, and structural properties of cerebral arteries. Male C57BL/6N mice were flown 30 days in a Bion-M1 biosatellite. Basilar arteries isolated from spaceflight (SF) (n = 6), habitat control (HC) (n = 6), and vivarium control (VC) (n = 16) mice were used for in vitro functional and mechanical testing and histological structural analysis. The results demonstrate that vasoconstriction elicited through a voltage-gated Ca2+ mechanism (30–80 mM KCl) and thromboxane A2 receptors (10−8 − 3 × 10−5 M U46619) are lower in cerebral arteries from SF mice. Inhibition of Rho-kinase activity (1 μM Y27632) abolished group differences in U46619-evoked contractions. Endothelium-dependent vasodilation elicited by acetylcholine (10 μM, 2 μM U46619 preconstriction) was virtually absent in cerebral arteries from SF mice. The pressure-diameter relation was lower in arteries from SF mice relative to that in HC mice, which was not related to differences in the extracellular matrix protein elastin or collagen content or the elastin/collagen ratio in the basilar arteries. Diameter, medial wall thickness, and medial cross-sectional area of unpressurized basilar arteries were not different among groups. These results suggest that the microgravity-induced attenuation of both vasoconstrictor and vasodilator properties may limit the range of vascular control of cerebral perfusion or impair the distribution of brain blood flow during periods of stress. PMID:25593287

The Effects of Spaceflight on Neurocognitive Performance: Extent, Longevity, and Neural Bases

NASA Technical Reports Server (NTRS)

Seidler, Rachael D.; Bloomberg, Jacob; Wood, Scott; Mason, Sara; Mulavara, Ajit; Kofman, Igor; De Dios, Yiri; Gadd, Nicole; Stepanyan, Vahagn; Szecsy, Darcy

2017-01-01

Spaceflight effects on gait, balance, & manual motor control have been well studied; some evidence for cognitive deficits. Rodent cortical motor & sensory systems show neural structural alterations with spaceflight. We found extensive changes in behavior, brain structure & brain function following 70 days of HDBR. Specific Aim: Aim 1-Identify changes in brain structure, function, and network integrity as a function of spaceflight and characterize their time course. Aim 2-Specify relationships between structural and functional brain changes and performance and characterize their time course.

Femoral Head Bone Loss Following Short and Long-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Blaber, E. A.; Cheng-Campbell, M.; Almeida, E. A. C.

2016-01-01

Exposure to mechanical unloading during spaceflight is known to have significant effects on the musculoskeletal system. Our ongoing studies with the mouse bone model have identified the failure of normal stem cell-based tissue regeneration, in addition to tissue degeneration, as a significant concern for long-duration spaceflight, especially in the mesenchymal and hematopoietic tissue lineages. The 30-day BionM1 and the 37-day Rodent Research 1 (RR1) missions enabled the possibility of studying these effects in long-duration microgravity experiments. We hypothesized that the inhibition of stem cell-based tissue regeneration in short-duration spaceflight would continue during long-duration spaceflight and furthermore would result in significant tissue alterations. MicroCT analysis of BionM1 femurs revealed 31% decrease in bone volume ratio, a 14% decrease in trabecular thickness, and a 20% decrease in trabecular number in the femoral head of space-flown mice. Furthermore, high-resolution MicroCT and immunohistochemical analysis of spaceflight tissues revealed a severe disruption of the epiphyseal boundary, resulting in endochondral ossification of the femoral head and perforation of articular cartilage by bone. This suggests that spaceflight in microgravity may cause rapid induction of an aging-like phenotype with signs of osteoarthritic disease in the hip joint. However, mice from RR1 exhibited significant bone loss in the femoral head but did not exhibit the severe aging and disease-like phenotype observed during BionM1.This may be due to increased physical activity in the RH hardware. Immunohistochemical analysis of the epiphyseal plate and investigation of cellular proliferation and differentiation pathways within the marrow compartment and whole bone tissue is currently being conducted to determine alterations in stem cell-based tissue regeneration between these experiments. Our results show that the observed inhibition of stem cell-based tissue regeneration

Femoral Head Bone Loss Following Short and Long-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Blaber, Elizabeth A.; Cheng-Campbell, Margareth A.; Almeida, Eduardo A. C.

2016-01-01

Exposure to mechanical unloading during spaceflight is known to have significant effects on the musculoskeletal system. Our ongoing studies with the mouse bone model have identified the failure of normal stem cell-based tissue regeneration, in addition to tissue degeneration, as a significant concern for long-duration spaceflight, especially in the mesenchymal and hematopoietic tissue lineages. The 30-day BionM1 and the 37-day Rodent Research 1 (RR1) missions enabled the possibility of studying these effects in long-duration microgravity experiments. We hypothesized that the inhibition of stem cell-based tissue regeneration in short-duration spaceflight would continue during long-duration spaceflight and furthermore would result in significant tissue alterations. MicroCT analysis of BionM1 femurs revealed 31 decrease in bone volume ratio, a 14 decrease in trabecular thickness, and a 20 decrease in trabecular number in the femoral head of space-flown mice. Furthermore, high-resolution MicroCT and immunohistochemical analysis of spaceflight tissues revealed a severe disruption of the epiphyseal boundary, resulting in endochondral ossification of the femoral head and perforation of articular cartilage by bone. This suggests that spaceflight in microgravity may cause rapid induction of an aging-like phenotype with signs of osteoarthritic disease in the hip joint. However, mice from RR1 exhibited significant bone loss in the femoral head but did not exhibit the severe aging and disease-like phenotype observed during BionM1. This may be due to increased physical activity in the RH hardware. Immunohistochemical analysis of the epiphyseal plate and investigation of cellular proliferation and differentiation pathways within the marrow compartment and whole bone tissue is currently being conducted to determine alterations in stem cell-based tissue regeneration between these experiments. Our results show that the observed inhibition of stem cell-based tissue regeneration

Spaceflight Effect on White Matter Structural Integrity

NASA Technical Reports Server (NTRS)

Lee, Jessica K.; Kopplemans, Vincent; Paternack, Ofer; Bloomberg, Jacob J.; Mulavara, Ajitkumar P.; Seidler, Rachael D.

2017-01-01

Recent reports of elevated brain white matter hyperintensity (WMH) counts and volume in postflight astronaut MRIs suggest that further examination of spaceflight's impact on the microstructure of brain white matter is warranted. To this end, retrospective longitudinal diffusion-weighted MRI scans obtained from 15 astronauts were evaluated. In light of the recent reports of microgravity-induced cephalad fluid shift and gray matter atrophy seen in astronauts, we applied a technique to estimate diffusion tensor imaging (DTI) metrics corrected for free water contamination. This approach enabled the analysis of white matter tissue-specific alterations that are unrelated to fluid shifts, occurring from before spaceflight to after landing. After spaceflight, decreased fractional anisotropy (FA) values were detected in an area encompassing the superior and inferior longitudinal fasciculi and the inferior fronto-occipital fasciculus. Increased radial diffusivity (RD) and decreased axial diffusivity (AD) were also detected within overlapping regions. In addition, FA values in the corticospinal tract decreased and RD measures in the precentral gyrus white matter increased from before to after flight. The results show disrupted structural connectivity of white matter in tracts involved in visuospatial processing, vestibular function, and movement control as a result of spaceflight. The findings may help us understand the structural underpinnings of the extensive spaceflight-induced sensorimotor remodeling. Prospective longitudinal assessment of the white matter integrity in astronauts is needed to characterize the evolution of white matter microstructural changes associated with spaceflight, their behavioral consequences, and the time course of recovery. Supported by a grant from the National Space Biomedical Research Institute, NASA NCC 9-58.

Brain structural plasticity with spaceflight.

PubMed

Koppelmans, Vincent; Bloomberg, Jacob J; Mulavara, Ajitkumar P; Seidler, Rachael D

2016-01-01

Humans undergo extensive sensorimotor adaptation during spaceflight due to altered vestibular inputs and body unloading. No studies have yet evaluated the effects of spaceflight on human brain structure despite the fact that recently reported optic nerve structural changes are hypothesized to occur due to increased intracranial pressure occurring with microgravity. This is the first report on human brain structural changes with spaceflight. We evaluated retrospective longitudinal T2-weighted MRI scans and balance data from 27 astronauts (thirteen ~2-week shuttle crew members and fourteen ~6-month International Space Station crew members) to determine spaceflight effects on brain structure, and whether any pre to postflight brain changes are associated with balance changes. Data were obtained from the NASA Lifetime Surveillance of Astronaut Health. Brain scans were segmented into gray matter maps and normalized into MNI space using a stepwise approach through subject specific templates. Non-parametric permutation testing was used to analyze pre to postflight volumetric gray matter changes. We found extensive volumetric gray matter decreases, including large areas covering the temporal and frontal poles and around the orbits. This effect was larger in International Space Station versus shuttle crew members in some regions. There were bilateral focal gray matter increases within the medial primary somatosensory and motor cortex; i.e., the cerebral areas where the lower limbs are represented. These intriguing findings are observed in a retrospective data set; future prospective studies should probe the underlying mechanisms and behavioral consequences.

Spaceflight modulates gene expression in the whole blood of astronauts.

PubMed

Barrila, Jennifer; Ott, C Mark; LeBlanc, Carly; Mehta, Satish K; Crabbé, Aurélie; Stafford, Phillip; Pierson, Duane L; Nickerson, Cheryl A

2016-01-01

Astronauts are exposed to a unique combination of stressors during spaceflight, which leads to alterations in their physiology and potentially increases their susceptibility to disease, including infectious diseases. To evaluate the potential impact of the spaceflight environment on the regulation of molecular pathways mediating cellular stress responses, we performed a first-of-its-kind pilot study to assess spaceflight-related gene-expression changes in the whole blood of astronauts. Using an array comprised of 234 well-characterized stress-response genes, we profiled transcriptomic changes in six astronauts (four men and two women) from blood preserved before and immediately following the spaceflight. Differentially regulated transcripts included those important for DNA repair, oxidative stress, and protein folding/degradation, including HSP90AB1 , HSP27 , GPX1 , XRCC1 , BAG-1 , HHR23A , FAP48 , and C-FOS . No gender-specific differences or relationship to number of missions flown was observed. This study provides a first assessment of transcriptomic changes occurring in the whole blood of astronauts in response to spaceflight.

Spaceflight modulates gene expression in the whole blood of astronauts

PubMed Central

Barrila, Jennifer; Ott, C Mark; LeBlanc, Carly; Mehta, Satish K; Crabbé, Aurélie; Stafford, Phillip; Pierson, Duane L; Nickerson, Cheryl A

2016-01-01

Astronauts are exposed to a unique combination of stressors during spaceflight, which leads to alterations in their physiology and potentially increases their susceptibility to disease, including infectious diseases. To evaluate the potential impact of the spaceflight environment on the regulation of molecular pathways mediating cellular stress responses, we performed a first-of-its-kind pilot study to assess spaceflight-related gene-expression changes in the whole blood of astronauts. Using an array comprised of 234 well-characterized stress-response genes, we profiled transcriptomic changes in six astronauts (four men and two women) from blood preserved before and immediately following the spaceflight. Differentially regulated transcripts included those important for DNA repair, oxidative stress, and protein folding/degradation, including HSP90AB1, HSP27, GPX1, XRCC1, BAG-1, HHR23A, FAP48, and C-FOS. No gender-specific differences or relationship to number of missions flown was observed. This study provides a first assessment of transcriptomic changes occurring in the whole blood of astronauts in response to spaceflight. PMID:28725744

Long-term exposure to spaceflight conditions affects bacterial response to antibiotics.

PubMed

Juergensmeyer, M A; Juergensmeyer, E A; Guikema, J A

1999-01-01

Bacteria exposed to the spaceflight environment have been shown to have an increased growth rate and an increased resistance to antibiotics. The mechanism of resistance has not yet been identified, as the resistance is quickly lost upon return to Earth. To more fully characterize the spaceflight-induced resistance to antibiotics, 4 species of bacteria were exposed to microgravity for 4 months on the Space Station MIR. Upon return to Earth, these cultures were challenged with a suite of 12 antibiotics of varying modes of action. In contrast to reports from short-term space flights, we find that long-term exposure to microgravity causes bacteria to become more susceptible to most, but not all, antibiotics. Each species responds differently to the suite of antibiotics, frequently becoming less resistant, but occasionally more resistant to the antibiotic. A pattern enabling prediction of response is not yet discernible. While contradicting the results from short-term pure culture research, this experiment confirms results from astronaut and cosmonaut skin flora samples.

Media Ion Composition Controls Regulatory and Virulence Response of Salmonella in Spaceflight

PubMed Central

Wilson, James W.; Ott, C. Mark; Quick, Laura; Davis, Richard; zu Bentrup, Kerstin Höner; Crabbé, Aurélie; Richter, Emily; Sarker, Shameema; Barrila, Jennifer; Porwollik, Steffen; Cheng, Pui; McClelland, Michael; Tsaprailis, George; Radabaugh, Timothy; Hunt, Andrea; Shah, Miti; Nelman-Gonzalez, Mayra; Hing, Steve; Parra, Macarena; Dumars, Paula; Norwood, Kelly; Bober, Ramona; Devich, Jennifer; Ruggles, Ashleigh; CdeBaca, Autumn; Narayan, Satro; Benjamin, Joseph; Goulart, Carla; Rupert, Mark; Catella, Luke; Schurr, Michael J.; Buchanan, Kent; Morici, Lisa; McCracken, James; Porter, Marc D.; Pierson, Duane L.; Smith, Scott M.; Mergeay, Max; Leys, Natalie; Stefanyshyn-Piper, Heidemarie M.; Gorie, Dominic; Nickerson, Cheryl A.

2008-01-01

The spaceflight environment is relevant to conditions encountered by pathogens during the course of infection and induces novel changes in microbial pathogenesis not observed using conventional methods. It is unclear how microbial cells sense spaceflight-associated changes to their growth environment and orchestrate corresponding changes in molecular and physiological phenotypes relevant to the infection process. Here we report that spaceflight-induced increases in Salmonella virulence are regulated by media ion composition, and that phosphate ion is sufficient to alter related pathogenesis responses in a spaceflight analogue model. Using whole genome microarray and proteomic analyses from two independent Space Shuttle missions, we identified evolutionarily conserved molecular pathways in Salmonella that respond to spaceflight under all media compositions tested. Identification of conserved regulatory paradigms opens new avenues to control microbial responses during the infection process and holds promise to provide an improved understanding of human health and disease on Earth. PMID:19079590

Human cerebral autoregulation before, during and after spaceflight.

PubMed

Iwasaki, Ken-ichi; Levine, Benjamin D; Zhang, Rong; Zuckerman, Julie H; Pawelczyk, James A; Diedrich, André; Ertl, Andrew C; Cox, James F; Cooke, William H; Giller, Cole A; Ray, Chester A; Lane, Lynda D; Buckey, Jay C; Baisch, Friedhelm J; Eckberg, Dwain L; Robertson, David; Biaggioni, Italo; Blomqvist, C Gunnar

2007-03-15

Exposure to microgravity alters the distribution of body fluids and the degree of distension of cranial blood vessels, and these changes in turn may provoke structural remodelling and altered cerebral autoregulation. Impaired cerebral autoregulation has been documented following weightlessness simulated by head-down bed rest in humans, and is proposed as a mechanism responsible for postspaceflight orthostatic intolerance. In this study, we tested the hypothesis that spaceflight impairs cerebral autoregulation. We studied six astronauts approximately 72 and 23 days before, after 1 and 2 weeks in space (n = 4), on landing day, and 1 day after the 16 day Neurolab space shuttle mission. Beat-by-beat changes of photoplethysmographic mean arterial pressure and transcranial Doppler middle cerebral artery blood flow velocity were measured during 5 min of spontaneous breathing, 30 mmHg lower body suction to simulate standing in space, and 10 min of 60 deg passive upright tilt on Earth. Dynamic cerebral autoregulation was quantified by analysis of the transfer function between spontaneous changes of mean arterial pressure and cerebral artery blood flow velocity, in the very low- (0.02-0.07 Hz), low- (0.07-0.20 Hz) and high-frequency (0.20-0.35 Hz) ranges. Resting middle cerebral artery blood flow velocity did not change significantly from preflight values during or after spaceflight. Reductions of cerebral blood flow velocity during lower body suction were significant before spaceflight (P < 0.05, repeated measures ANOVA), but not during or after spaceflight. Absolute and percentage reductions of mean (+/- s.e.m.) cerebral blood flow velocity after 10 min upright tilt were smaller after than before spaceflight (absolute, -4 +/- 3 cm s(-1) after versus -14 +/- 3 cm s(-1) before, P = 0.001; and percentage, -8.0 +/- 4.8% after versus -24.8 +/- 4.4% before, P < 0.05), consistent with improved rather than impaired cerebral blood flow regulation. Low-frequency gain decreased

Inflight Pharmacokinetic and Pharmacodynamic Responses to Medications Commonly Used in Spaceflight

NASA Technical Reports Server (NTRS)

Wotring, V. E.; Derendorf, H.; Kast, J.; Barger, L.; Basner, M.

2016-01-01

Researchers do not know if medications act the same in the spaceflight environment as they do on Earth. Aspects of the spaceflight environment (low gravity, radiation exposure, closed environment, stress) have been shown to alter human physiology. Some of these physiological changes could be expected to alter either pharmacokinetics (PK, how the body absorbs, distributes, metabolizes and excretes administered medications) or pharmacodynamics (PD, receptors or signaling systems that are the targets of medication action). Anecdotal data has suggested that, at least for certain medications or indications, inflight medication efficacy is poor. In order to prepare for exploration missions where speedy evacuation to Earth may not be a possibility, the likelihood of unexpected medication action must be determined.

Respiratory modulation of cardiovascular rhythms before and after short-duration human spaceflight.

PubMed

Verheyden, B; Beckers, F; Couckuyt, K; Liu, J; Aubert, A E

2007-12-01

Astronauts commonly return from space with altered short-term cardiovascular dynamics and blunted baroreflex sensitivity. Although many studies have addressed this issue, post-flight effects on the dynamic circulatory control remain incompletely understood. It is not clear how long the cardiovascular system needs to recover from spaceflight as most post-flight investigations only extended between a few days and 2 weeks. In this study, we examined the effect of short-duration spaceflight (1-2 weeks) on respiratory-mediated cardiovascular rhythms in five cosmonauts. Two paced-breathing protocols at 6 and 12 breaths min(-1) were performed in the standing and supine positions before spaceflight, and after 1 and 25 days upon return. Dynamic baroreflex function was evaluated by transfer function analysis between systolic pressure and the RR intervals. Post-flight orthostatic blood pressure control was preserved in all cosmonauts. In the standing position after spaceflight there was an increase in heart rate (HR) of approx. 20 beats min(-1) or more. Averaged for all five cosmonauts, respiratory sinus dysrhythmia and transfer gain reduced to 40% the day after landing, and had returned to pre-flight levels after 25 days. Low-frequency gain decreased from 6.6 (3.4) [mean (SD)] pre-flight to 3.9 (1.6) post-flight and returned to 5.7 (1.3) ms mmHg(-1) after 25 days upon return to Earth. Unlike alterations in the modulation of HR, blood pressure dynamics were not significantly different between pre- and post-flight sessions. Our results indicate that short-duration spaceflight reduces respiratory modulation of HR and decreases cardiac baroreflex gain without affecting post-flight arterial blood pressure dynamics. Altered respiratory modulation of human autonomic rhythms does not persist until 25 days upon return to Earth.

Spaceflight Sensorimotor Analogs: Simulating Acute and Adaptive Effects

NASA Technical Reports Server (NTRS)

Taylor, Laura C.; Harm, Deborah L.; Kozlovskaya, Inessa; Reschke, Millard F.; Wood, Scott J.

2009-01-01

Adaptive changes in sensorimotor function during spaceflight are reflected by spatial disorientation, motion sickness, gaze destabilization and decrements in balance, locomotion and eye-hand coordination that occur during and following transitions between different gravitational states. The purpose of this study was to conduct a meta-synthesis of data from spaceflight analogs to evaluate their effectiveness in simulating adaptive changes in sensorimotor function. METHODS. The analogs under review were categorized as either acute analogs used to simulate performance decrements accompanied with transient changes, or adaptive analogs used to drive sensorimotor learning to altered sensory feedback. The effectiveness of each analog was evaluated in terms of mechanisms of action, magnitude and time course of observed deficits compared to spaceflight data, and the effects of amplitude and exposure duration. RESULTS. Parabolic flight has been used extensively to examine effects of acute variation in gravitational loads, ranging from hypergravity to microgravity. More recently, galvanic vestibular stimulation has been used to elicit acute postural, locomotor and gaze dysfunction by disrupting vestibular afferents. Patient populations, e.g., with bilateral vestibular loss or cerebellar dysfunction, have been proposed to model acute sensorimotor dysfunction. Early research sponsored by NASA involved living onboard rotating rooms, which appeared to approximate the time course of adaptation and post-exposure recovery observed in astronauts following spaceflight. Exposure to different bed-rest paradigms (6 deg head down, dry immersion) result in similar motor deficits to that observed following spaceflight. Shorter adaptive analogs have incorporated virtual reality environments, visual distortion paradigms, exposure to conflicting tilt-translation cues, and exposure to 3Gx centrifugation. As with spaceflight, there is considerable variability in responses to most of the analogs

Effects of spaceflight on trabecular bone in rats

NASA Technical Reports Server (NTRS)

Jee, W. S. S.; Wronski, T. J.; Morey, E. R.; Kimmel, D. B.

1983-01-01

Alterations in trabecular bone were observed in growing male Wistar rats after 18.5 days of orbital flight on the COSMOS 1129 biosatellite. Spaceflight induced a decreased mass of mineralized tissue and an increased fat content of the bone marrow in the proximal tibial and humeral metaphyses. The osteoblast population appeared to decline immediately adjacent to the growth cartilage-metaphyseal junction, but osteoclast numbers were unchanged. These results suggested that bone formation may have been inhibited during spaceflight, but resorption remained constant. With the exception of trabecular bone mass in the proximal tibia, the observed skeletal changes returned to normal during a 29-day postflight period.

Blood pressure and mesenteric resistance arterial function after spaceflight

NASA Technical Reports Server (NTRS)

Hatton, Daniel C.; Yue, Qi; Chapman, Justin; Xue, Hong; Dierickx, Jacqueline; Roullet, Chantal; Coste, Sarah; Roullet, Jean Baptiste; McCarron, David A.

2002-01-01

Ground studies indicate that spaceflight may diminish vascular contraction. To examine that possibility, vascular function was measured in spontaneously hypertensive rats immediately after an 18-day shuttle flight. Isolated mesenteric resistance arterial responses to cumulative additions of norepinephrine, acetylcholine, and sodium nitroprusside were measured using wire myography within 17 h of landing. After flight, maximal contraction to norepinephrine was attenuated (P < 0.001) as was relaxation to acetylcholine (P < 0.001) and sodium nitroprusside (P < 0.05). At high concentrations, acetylcholine caused vascular contraction in vessels from flight animals but not in vessels from vivarium control animals (P < 0.05). The results are consistent with data from ground studies and indicate that spaceflight causes both endothelial-dependent and endothelial-independent alterations in vascular function. The resulting decrement in vascular function may contribute to orthostatic intolerance after spaceflight.

Aging and Spaceflight: Catalase Targeted to Mitochondria Alters Skeletal Structure and Responses to Musculoskeletal Disuse

NASA Technical Reports Server (NTRS)

Globus, Ruth K.; Tahimic, Candice; Schreurs, Ann-Sofie

2018-01-01

Microgravity and ionizing radiation in the spaceflight environment pose multiple challenges to homeostasis and may contribute to cellular stress. Effects may include increased generation of reactive oxygen species (ROS), DNA damage and repair error, cell cycle arrest, cell senescence or death. Our central hypothesis is that prolonged exposure to the spaceflight environment leads to excess production of ROS and oxidative damage, culminating in accelerated tissue degeneration which resembles aging. The main goal of this project is to determine the importance of cellular redox defense for physiological adaptations and tissue degeneration in the space environment. To accomplish this, we will use both wildtype (WT) mice and a well-established, genetically-engineered animal model (mCAT mice) which displays extended lifespan (Schriner et al. 2005). The animal model selected to test these ideas is engineered to quench ROS in mitochondria by targeted over-expression of the human catalase gene to the mitochondrial matrix. We showed previously that mCAT mice express the catalase transgene in skeletal tissues, bone forming osteoblasts, and bone resorbing osteoclasts. In addition, mCAT mice also display increased catalase activity in bone. Our findings revealed that exposure of adult, male, C57Bl/6J mice to simulated spaceflight (hindlimb unloading and gamma radiation) led to an increase in markers of oxidative damage (malondialdehyde, 4-hydroxynonenol) in skeletal tissue of WT mice but not mCAT mice. To extend our hypothesis to other, spaceflight-relevant tissues, we are performing a ground-based study simulating 30 days of spaceflight by hindlimb unloading to determine potential protective effects of mitochondrial catalase activity on aging of multiple tissues (cardiovascular, nervous and skeletal).

Spaceflight-Induced Bone Loss Alters Failure Mode and Reduces Bending Strength in Murine Spinal Segments

PubMed Central

Berg-Johansen, Britta; Liebenberg, Ellen C.; Li, Alfred; Macias, Brandon R.; Hargens, Alan R.; Lotz, Jeffrey C.

2017-01-01

Intervertebral disc herniation rates are quadrupled in astronauts following spaceflight. While bending motions are main contributors to herniation, the effects of microgravity on the bending properties of spinal discs are unknown. Consequently, the goal of this study was to quantify the bending properties of tail discs from mice with or without microgravity exposure. Caudal motion segments from six mice returned from a 30-day Bion M1 mission and eight vivarium controls were loaded to failure in four-point bending. After testing, specimens were processed using histology to determine the location of failure, and adjacent motion segments were scanned with micro-computed tomography (μCT) to quantify bone properties. We observed that spaceflight significantly shortened the nonlinear toe region of the force-displacement curve by 32% and reduced the bending strength by 17%. Flight mouse spinal segments tended to fail within the growth plate and epiphyseal bone, while controls tended to fail at the disc-vertebra junction. Spaceflight significantly reduced vertebral bone volume fraction, bone mineral density, and trabecular thickness, which may explain the tendency of flight specimens to fail within the epiphyseal bone. Together, these results indicate that vertebral bone loss during spaceflight may degrade spine bending properties and contribute to increased disc herniation risk in astronauts. PMID:26285046

Spaceflight Transcriptomes: Unique Responses to a Novel Environment

PubMed Central

Paul, Anna-Lisa; Zupanska, Agata K.; Ostrow, Dejerianne T.; Zhang, Yanping; Sun, Yijun; Li, Jian-Liang; Shanker, Savita; Farmerie, William G.; Amalfitano, Claire E.

2012-01-01

Abstract The spaceflight environment presents unique challenges to terrestrial biology, including but not limited to the direct effects of gravity. As we near the end of the Space Shuttle era, there remain fundamental questions about the response and adaptation of plants to orbital spaceflight conditions. We address a key baseline question of whether gene expression changes are induced by the orbital environment, and then we ask whether undifferentiated cells, cells presumably lacking the typical gravity response mechanisms, perceive spaceflight. Arabidopsis seedlings and undifferentiated cultured Arabidopsis cells were launched in April, 2010, as part of the BRIC-16 flight experiment on STS-131. Biologically replicated DNA microarray and averaged RNA digital transcript profiling revealed several hundred genes in seedlings and cell cultures that were significantly affected by launch and spaceflight. The response was moderate in seedlings; only a few genes were induced by more than 7-fold, and the overall intrinsic expression level for most differentially expressed genes was low. In contrast, cell cultures displayed a more dramatic response, with dozens of genes showing this level of differential expression, a list comprised primarily of heat shock–related and stress-related genes. This baseline transcriptome profiling of seedlings and cultured cells confirms the fundamental hypothesis that survival of the spaceflight environment requires adaptive changes that are both governed and displayed by alterations in gene expression. The comparison of intact plants with cultures of undifferentiated cells confirms a second hypothesis: undifferentiated cells can detect spaceflight in the absence of specialized tissue or organized developmental structures known to detect gravity. Key Words: Tissue culture—Microgravity—Low Earth orbit—Space Shuttle—Microarray. Astrobiology 12, 40–56. PMID:22221117

The effects of spaceflight on mammary metabolism in pregnant rats

NASA Technical Reports Server (NTRS)

Plaut, K.; Maple, R.; Vyas, C.; Munaim, S.; Darling, A.; Casey, T.; Alberts, J. R.

1999-01-01

The effects of spaceflight on mammary metabolism of 10 pregnant rats was measured on Day 20 of pregnancy and after parturition. Rats were flown on the space shuttle from Day 11 through Day 20 of pregnancy. After their return to earth, glucose oxidation to carbon dioxide increased 43% (P < 0.05), and incorporation into fatty acids increased 300% (P < 0.005) compared to controls. It is unclear whether the enhanced glucose use is due to spaceflight or a response to landing. Casein mRNA and gross histology were not altered at Day 20 of pregnancy. Six rats gave birth (on Day 22 to 23 of pregnancy) and mammary metabolic activity was measured immediately postpartum. The earlier effects of spaceflight were no longer apparent. There was also no difference in expression of beta-casein mRNA. It is clear from these studies that spaceflight does not impair the normal development of the mammary gland, its ability to use glucose, nor the ability to express mRNA for a major milk protein.

Alterations in the Spectrum of Spontaneous Rifampicin-Resistance Mutations in the Bacillus subtilis rpoB Gene after Cultivation in the Human Spaceflight Environment

PubMed Central

Fajardo-Cavazos, Patricia; Leehan, Joshua D.; Nicholson, Wayne L.

2018-01-01

The effect of Bacillus subtilis exposure to the human spaceflight environment on growth, mutagenic frequency, and spectrum of mutations to rifampicin resistance (RifR) was investigated. B. subtilis cells were cultivated in Biological Research in Canister-Petri Dish Fixation Units (BRIC-PDFUs) on two separate missions to the International Space Station (ISS), dubbed BRIC-18 and BRIC-21, with matching asynchronous ground controls. No statistically significant difference in either growth or in the frequency of mutation to RifR was found in either experiment. However, nucleotide sequencing of the RifR regions of the rpoB gene from RifR mutants revealed dramatic differences in the spectrum of mutations between flight (FL) and ground control (GC) samples, including two newly discovered rpoB alleles in the FL samples (Q137R and L489S). The results strengthen the idea that exposure to the human spaceflight environment causes unique stresses on bacteria, leading to alterations in their mutagenic potential. PMID:29491852

Alterations in the Spectrum of Spontaneous Rifampicin-Resistance Mutations in the Bacillus subtilis rpoB Gene after Cultivation in the Human Spaceflight Environment.

PubMed

Fajardo-Cavazos, Patricia; Leehan, Joshua D; Nicholson, Wayne L

2018-01-01

The effect of Bacillus subtilis exposure to the human spaceflight environment on growth, mutagenic frequency, and spectrum of mutations to rifampicin resistance (Rif R ) was investigated. B. subtilis cells were cultivated in Biological Research in Canister-Petri Dish Fixation Units (BRIC-PDFUs) on two separate missions to the International Space Station (ISS), dubbed BRIC-18 and BRIC-21, with matching asynchronous ground controls. No statistically significant difference in either growth or in the frequency of mutation to Rif R was found in either experiment. However, nucleotide sequencing of the Rif R regions of the rpoB gene from Rif R mutants revealed dramatic differences in the spectrum of mutations between flight (FL) and ground control (GC) samples, including two newly discovered rpoB alleles in the FL samples (Q137R and L489S). The results strengthen the idea that exposure to the human spaceflight environment causes unique stresses on bacteria, leading to alterations in their mutagenic potential.

Global transcriptomic analysis suggests carbon dioxide as an environmental stressor in spaceflight: A systems biology GeneLab case study.

PubMed

Beheshti, Afshin; Cekanaviciute, Egle; Smith, David J; Costes, Sylvain V

2018-03-08

Spaceflight introduces a combination of environmental stressors, including microgravity, ionizing radiation, changes in diet and altered atmospheric gas composition. In order to understand the impact of each environmental component on astronauts it is important to investigate potential influences in isolation. Rodent spaceflight experiments involve both standard vivarium cages and animal enclosure modules (AEMs), which are cages used to house rodents in spaceflight. Ground control AEMs are engineered to match the spaceflight environment. There are limited studies examining the biological response invariably due to the configuration of AEM and vivarium housing. To investigate the innate global transcriptomic patterns of rodents housed in spaceflight-matched AEM compared to standard vivarium cages we utilized publicly available data from the NASA GeneLab repository. Using a systems biology approach, we observed that AEM housing was associated with significant transcriptomic differences, including reduced metabolism, altered immune responses, and activation of possible tumorigenic pathways. Although we did not perform any functional studies, our findings revealed a mild hypoxic phenotype in AEM, possibly due to atmospheric carbon dioxide that was increased to match conditions in spaceflight. Our investigation illustrates the process of generating new hypotheses and informing future experimental research by repurposing multiple space-flown datasets.

Vitamin K Status in Spaceflight and Ground-Based Models of Spaceflight

PubMed Central

Zwart, Sara R; Booth, Sarah L; Peterson, James W; Wang, Zuwei; Smith, Scott M

2011-01-01

Bone loss is a well-documented change during and after long-duration spaceflight. Many types of countermeasures to bone loss have been proposed, including vitamin K supplementation. The objective of this series of studies was to measure change in vitamin K status in response to microgravity under a variety of spaceflight and spaceflight analog (model) conditions, including long-duration spaceflight studies (n = 15), three bed rest studies (n = 15, 49, and 24), and a 14-day saturation dive (n= 6). In crew members who flew 2–6 months on the International Space Station, in-flight and postflight plasma phylloquinone concentrations were unchanged from the preflight mean. Consistent with this finding, urinary γ-carboxyglutamic acid (GLA), a measure of vitamin K-dependent protein turnover, did not change in response to flight. Serum undercarboxylated osteocalcin (%ucOC), a measure of vitamin K function, was generally unchanged in response to flight. Spaceflight findings were corroborated by findings of no changes in phylloquinone, urinary GLA, or %ucOC during or after bed rest in three separate bed rest studies (21–90 days in duration) or after a 14-day saturation dive. The data presented here do not support either a need for vitamin K supplementation during spaceflight or the suggestion of using vitamin K as a bone loss countermeasure in spaceflight. © 2011 American Society for Bone and Mineral Research. PMID:21541997

Leukocyte subsets and neutrophil function after short-term spaceflight

NASA Technical Reports Server (NTRS)

Stowe, R. P.; Sams, C. F.; Mehta, S. K.; Kaur, I.; Jones, M. L.; Feeback, D. L.; Pierson, D. L.

1999-01-01

Changes in leukocyte subpopulations and function after spaceflight have been observed but the mechanisms underlying these changes are not well defined. This study investigated the effects of short-term spaceflight (8-15 days) on circulating leukocyte subsets, stress hormones, immunoglobulin levels, and neutrophil function. At landing, a 1.5-fold increase in neutrophils was observed compared with preflight values; lymphocytes were slightly decreased, whereas the results were variable for monocytes. No significant changes were observed in plasma levels of immunoglobulins, cortisol, or adrenocorticotropic hormone. In contrast, urinary epinephrine, norepinephrine, and cortisol were significantly elevated at landing. Band neutrophils were observed in 9 of 16 astronauts. Neutrophil chemotactic assays showed a 10-fold decrease in the optimal dose response after landing. Neutrophil adhesion to endothelial cells was increased both before and after spaceflight. At landing, the expression of MAC-1 was significantly decreased while L-selectin was significantly increased. These functional alterations may be of clinical significance on long-duration space missions.

Regulation of body fluid volume and electrolyte concentrations in spaceflight.

PubMed

Smith, S M; Krauhs, J M; Leach, C S

1997-01-01

Despite a number of difficulties in performing experiments during weightlessness, a great deal of information has been obtained concerning the effects of spaceflight on the regulation of body fluid and electrolytes. Many paradoxes and questions remain, however. Although body mass, extracellular fluid volume, and plasma volume are reduced during spaceflight and remain so at landing, the changes in total body water are comparatively small. Serum or plasma sodium and osmolality have generally been unchanged or reduced during the spaceflight, and fluid intake is substantially reduced, especially during the first of flight. The diuresis that was predicted to be caused by weightlessness, has only rarely been observed as an increased urine volume. What has been well established by now, is the occurrence of a relative diuresis, where fluid intake decreases more than urine volume does. Urinary excretion of electrolytes has been variable during spaceflight, but retention of fluid and electrolytes at landing has been consistently observed. The glomerular filtration rate was significantly elevated during the SLS missions, and water and electrolyte loading tests have indicated that renal function is altered during readaptation to Earth's gravity. Endocrine control of fluid volumes and electrolyte concentrations may be altered during weightlessness, but levels of hormones in body fluids do not conform to predictions based on early hypotheses. Antidiuretic hormone is not suppressed, though its level is highly variable and its secretion may be affected by space motion sickness and environmental factors. Plasma renin activity and aldosterone are generally elevated at landing, consistent with sodium retention, but inflight levels have been variable. Salt intake may be an important factor influencing the levels of these hormones. The circadian rhythm of cortisol has undoubtedly contributed to its variability, and little is known yet about the influence of spaceflight on circadian

Regulation of body fluid volume and electrolyte concentrations in spaceflight

NASA Technical Reports Server (NTRS)

Smith, S. M.; Krauhs, J. M.; Leach, C. S.

1997-01-01

Despite a number of difficulties in performing experiments during weightlessness, a great deal of information has been obtained concerning the effects of spaceflight on the regulation of body fluid and electrolytes. Many paradoxes and questions remain, however. Although body mass, extracellular fluid volume, and plasma volume are reduced during spaceflight and remain so at landing, the changes in total body water are comparatively small. Serum or plasma sodium and osmolality have generally been unchanged or reduced during the spaceflight, and fluid intake is substantially reduced, especially during the first of flight. The diuresis that was predicted to be caused by weightlessness, has only rarely been observed as an increased urine volume. What has been well established by now, is the occurrence of a relative diuresis, where fluid intake decreases more than urine volume does. Urinary excretion of electrolytes has been variable during spaceflight, but retention of fluid and electrolytes at landing has been consistently observed. The glomerular filtration rate was significantly elevated during the SLS missions, and water and electrolyte loading tests have indicated that renal function is altered during readaptation to Earth's gravity. Endocrine control of fluid volumes and electrolyte concentrations may be altered during weightlessness, but levels of hormones in body fluids do not conform to predictions based on early hypotheses. Antidiuretic hormone is not suppressed, though its level is highly variable and its secretion may be affected by space motion sickness and environmental factors. Plasma renin activity and aldosterone are generally elevated at landing, consistent with sodium retention, but inflight levels have been variable. Salt intake may be an important factor influencing the levels of these hormones. The circadian rhythm of cortisol has undoubtedly contributed to its variability, and little is known yet about the influence of spaceflight on circadian

Effects of Long Duration Spaceflight on Venous and Arterial Compliance in Astronants

NASA Technical Reports Server (NTRS)

Platts, Steven; Ribeiro, L. Christine

2014-01-01

1. Project Overview Visual impairment and intracranial pressure (VIIP) is a spaceflight-associated medical condition affecting at least a third of American astronauts who have flown International Space Station (ISS) missions. VIIP is defined primarily by visual acuity deficits and anatomical changes to eye structures. In some astronauts, eye-related changes do not revert back to the preflight state upon return to Earth. Our team will study some of the possible causes for this syndrome. This will be achieved by reviewing previous astronaut data for factors that may predispose astronauts to higher rates of developing this syndrome or greater severity of symptoms. Additionally, we will conduct 3 separate experiments that will characterize vessels in the head and neck and measure the effects of the experimental conditions on ocular structures and function. 2. Technical Summary The primary objective of this study is to determine whether vascular compliance is altered by spaceflight and whether such adaptations are related to the incidence of the VIIP. In particular, we will measure ocular parameters and vascular compliance in vessels of the head and neck in astronauts who have no spaceflight experience (Ground), in astronauts before, during, and after spaceflight (Flight), and in bed rest subjects with conditions similar to spaceflight (Bed Rest). Additionally, we will analyze astronaut data from the Lifetime Surveillance of Astronaut Health (LSAH) archives to determine which factors might be predictive of the development of VIIP (Data Mining). The project will be conducted in four separate, but related parts. Hypothesis The central hypothesis of this proposal is that exposure to the spaceflight environment aboard the ISS may lead to development of the VIIP syndrome (increased intracranial pressure and impaired visual acuity) and that this may be related to alterations in venous and/or arterial compliance in the head and neck. Specific Aims 1. To determine whether

The Effects of Spaceflight and Head Down Tilt Bed Rest on Neurocognitive Performance: Extent, Longevity, and Neural Bases

NASA Technical Reports Server (NTRS)

Seidler, Rachael D.; Bloomberg, Jacob; Wood, Scott; Mulavara, Ajit; Kofman, Igor; De Dios, Yiri; Gadd, Nicole; Stepanyan, Vahagn

2017-01-01

Spaceflight effects on gait, balance, & manual motor control have been well studied; some evidence for cognitive deficits. Rodent cortical motor & sensory systems show neural structural alterations with spaceflight. specific Aims: Aim 1-Identify changes in brain structure, function, and network integrity as a function of head down tilt bed rest and spaceflight, and characterize their time course. Aim 2-Specify relationships between structural and functional brain changes and performance and characterize their time course.

Altered Virome and Bacterial Microbiome in Human Immunodeficiency Virus-Associated Acquired Immunodeficiency Syndrome

PubMed Central

Monaco, Cynthia L.; Gootenberg, David B.; Zhao, Guoyan; Handley, Scott A.; Ghebremichael, Musie S.; Lim, Efrem S.; Lankowski, Alex; Baldridge, Megan T.; Wilen, Craig B.; Flagg, Meaghan; Norman, Jason M.; Keller, Brian C.; Luévano, Jesús Mario; Wang, David; Boum, Yap; Martin, Jeffrey N.; Hunt, Peter W.; Bangsberg, David R.; Siedner, Mark J.; Kwon, Douglas S.; Virgin, Herbert W.

2016-01-01

SUMMARY Human immunodeficiency virus (HIV) infection is associated with increased intestinal translocation of microbial products and enteropathy as well as alterations in gut bacterial communities. However, whether the enteric virome contributes to this infection and resulting immunodeficiency remains unknown. We characterized the enteric virome and bacterial microbiome in a cohort of Ugandan patients, including HIV-uninfected or HIV-infected subjects and those either treated with anti-retroviral therapy (ART) or untreated. Low peripheral CD4 T cell counts were associated with an expansion of enteric adenovirus sequences and this increase was independent of ART treatment. Additionally, the enteric bacterial microbiome of patients with lower CD4 T counts exhibited reduced phylogenetic diversity and richness with specific bacteria showing differential abundance, including increases in Enterobacteriaceae, which have been associated with inflammation. Thus, immunodeficiency in progressive HIV infection is associated with alterations in the enteric virome and bacterial microbiome, which may contribute to AIDS-associated enteropathy and disease progression. PMID:26962942

Altered Virome and Bacterial Microbiome in Human Immunodeficiency Virus-Associated Acquired Immunodeficiency Syndrome.

PubMed

Monaco, Cynthia L; Gootenberg, David B; Zhao, Guoyan; Handley, Scott A; Ghebremichael, Musie S; Lim, Efrem S; Lankowski, Alex; Baldridge, Megan T; Wilen, Craig B; Flagg, Meaghan; Norman, Jason M; Keller, Brian C; Luévano, Jesús Mario; Wang, David; Boum, Yap; Martin, Jeffrey N; Hunt, Peter W; Bangsberg, David R; Siedner, Mark J; Kwon, Douglas S; Virgin, Herbert W

2016-03-09

Human immunodeficiency virus (HIV) infection is associated with increased intestinal translocation of microbial products and enteropathy as well as alterations in gut bacterial communities. However, whether the enteric virome contributes to this infection and resulting immunodeficiency remains unknown. We characterized the enteric virome and bacterial microbiome in a cohort of Ugandan patients, including HIV-uninfected or HIV-infected subjects and those either treated with anti-retroviral therapy (ART) or untreated. Low peripheral CD4 T cell counts were associated with an expansion of enteric adenovirus sequences and this increase was independent of ART treatment. Additionally, the enteric bacterial microbiome of patients with lower CD4 T counts exhibited reduced phylogenetic diversity and richness with specific bacteria showing differential abundance, including increases in Enterobacteriaceae, which have been associated with inflammation. Thus, immunodeficiency in progressive HIV infection is associated with alterations in the enteric virome and bacterial microbiome, which may contribute to AIDS-associated enteropathy and disease progression. Copyright © 2016 Elsevier Inc. All rights reserved.

[Psychological issues in manned spaceflight].

PubMed

Zhang, Q J; Bai, Y Q

1999-04-01

As the duration of manned spaceflight becomes longer and as crews become more heterogeneous, psychological and interpersonal factors will be more important in affecting the safety of crew and flight mission. In space environment there are four types of stressors: physical, physiological, psychological and interpersonal. Psychological issues include "Asthenia", alteration in time sense, transcendent experiences, sleep problem, career motivation, psychosomatic symptoms and psychiatric issues. Interpersonal issues include interpersonal tension, interpersonal relationships decreased cohesiveness and deprivation, displacement [correction of dispiacement] of anger to outside personnel over time.

Root bacterial endophytes alter plant phenotype, but not physiology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henning, Jeremiah A.; Weston, David J.; Pelletier, Dale A.

Plant traits, such as root and leaf area, influence how plants interact with their environment and the diverse microbiota living within plants can influence plant morphology and physiology. Here, we explored how three bacterial strains isolated from the Populus root microbiome, influenced plant phenotype. Here, we chose three bacterial strains that differed in predicted metabolic capabilities, plant hormone production and metabolism, and secondary metabolite synthesis. We inoculated each bacterial strain on a single genotype of Populus trichocarpa and measured the response of plant growth related traits (root:shoot, biomass production, root and leaf growth rates) and physiological traits (chlorophyll content, netmore » photosynthesis, net photosynthesis at saturating light–A sat, and saturating CO 2–A max). Overall, we found that bacterial root endophyte infection increased root growth rate up to 184% and leaf growth rate up to 137% relative to non-inoculated control plants, evidence that plants respond to bacteria by modifying morphology. However, endophyte inoculation had no influence on total plant biomass and photosynthetic traits (net photosynthesis, chlorophyll content). In sum, bacterial inoculation did not significantly increase plant carbon fixation and biomass, but their presence altered where and how carbon was being allocated in the plant host.« less

Root bacterial endophytes alter plant phenotype, but not physiology

DOE PAGES

Henning, Jeremiah A.; Weston, David J.; Pelletier, Dale A.; ...

2016-11-01

Plant traits, such as root and leaf area, influence how plants interact with their environment and the diverse microbiota living within plants can influence plant morphology and physiology. Here, we explored how three bacterial strains isolated from the Populus root microbiome, influenced plant phenotype. Here, we chose three bacterial strains that differed in predicted metabolic capabilities, plant hormone production and metabolism, and secondary metabolite synthesis. We inoculated each bacterial strain on a single genotype of Populus trichocarpa and measured the response of plant growth related traits (root:shoot, biomass production, root and leaf growth rates) and physiological traits (chlorophyll content, netmore » photosynthesis, net photosynthesis at saturating light–A sat, and saturating CO 2–A max). Overall, we found that bacterial root endophyte infection increased root growth rate up to 184% and leaf growth rate up to 137% relative to non-inoculated control plants, evidence that plants respond to bacteria by modifying morphology. However, endophyte inoculation had no influence on total plant biomass and photosynthetic traits (net photosynthesis, chlorophyll content). In sum, bacterial inoculation did not significantly increase plant carbon fixation and biomass, but their presence altered where and how carbon was being allocated in the plant host.« less

Programmatic Considerations to Reduce the Risk of Adverse Renal Stone Events in Spaceflight

NASA Technical Reports Server (NTRS)

Antonsen, Erik; Pietrzyk, Robert

2017-01-01

Introduction: Microgravity exposure may alter the likelihood that astronauts will experience renal stones. The potential risk includes both acute and chronic health issues, with the potential for significant impact on mission objectives. Methods: To understand the role of the NASA's Human Research Program (HRP) research agenda in both preventing and addressing renal stones in spaceflight, current astronaut epidemiologic data and a summary of programmatic considerations are reviewed. Results: Although there has never been a symptomatic renal stone event in a U.S. crewmember during spaceflight, urine chemistry has been altered - likely due to induced changes in renal physiology as a result of exposure to microgravity. This may predispose astronauts to stone formation, leading the HRP to conduct and sponsor research to: 1) understand the risk of stone formation in space; 2) prevent stones from forming; and 3) address stones that may form by providing novel diagnostic and therapeutic approaches. Discussion: The development of a renal stone during spaceflight is a significant medical concern that requires the HRP to minimize this risk by providing the ability to prevent, diagnose, monitor and treat the condition during spaceflight. A discussion of the risk as NASA understands it is followed by an overview of the multiple mitigations currently under study, including novel ultrasound techniques for stone detection and manipulation, and how they may function as part of a larger exploration medical system.

Transcriptomic and proteomic responses of Serratia marcescens to spaceflight conditions involve large-scale changes in metabolic pathways

NASA Astrophysics Data System (ADS)

Wang, Yajuan; Yuan, Yanting; Liu, Jinwen; Su, Longxiang; Chang, De; Guo, Yinghua; Chen, Zhenhong; Fang, Xiangqun; Wang, Junfeng; Li, Tianzhi; Zhou, Lisha; Fang, Chengxiang; Yang, Ruifu; Liu, Changting

2014-04-01

The microgravity environment of spaceflight expeditions has been associated with altered microbial responses. This study explores the characterization of Serratia marcescensis grown in a spaceflight environment at the phenotypic, transcriptomic and proteomic levels. From November 1, 2011 to November 17, 2011, a strain of S. marcescensis was sent into space for 398 h on the Shenzhou VIII spacecraft, and ground simulation was performed as a control (LCT-SM213). After the flight, two mutant strains (LCT-SM166 and LCT-SM262) were selected for further analysis. Although no changes in the morphology, post-culture growth kinetics, hemolysis or antibiotic sensitivity were observed, the two mutant strains exhibited significant changes in their metabolic profiles after exposure to spaceflight. Enrichment analysis of the transcriptome showed that the differentially expressed genes of the two spaceflight strains and the ground control strain mainly included those involved in metabolism and degradation. The proteome revealed that changes at the protein level were also associated with metabolic functions, such as glycolysis/gluconeogenesis, pyruvate metabolism, arginine and proline metabolism and the degradation of valine, leucine and isoleucine. In summary S. marcescens showed alterations primarily in genes and proteins that were associated with metabolism under spaceflight conditions, which gave us valuable clues for future research.

SpaceDock: A Performance Task Platform for Spaceflight Operations

NASA Technical Reports Server (NTRS)

Marshburn, Thomas H.; Strangman, Gary E.; Strauss, Monica S.; Sutton, Jeffrey P.

2003-01-01

Preliminary evidence during both short- and long-duration spaceflight indicates that perceptual-motor coordination changes occur and persist in-flight. However, there is presently no in-flight method for evaluating astronaut performance on mission-critical tasks such as docking. We present a portable platform we have developed for attempting and evaluating docking, and describe the results of a pilot study wherein flight novices learned the docking task. Methods: A dual-joystick, six degrees of freedom platform-called SpaceDock-was developed to enable portable, adaptable performance testing in a spaceflight operations setting. Upon this platform, a simplified docking task was created, involving a constant rate of approach towards a docking target and requiring the user to correct translation in two dimensions and attitude orientation along one dimension (either pitch or roll). Ten flight naive subjects performed the task over a 45 min period and all joystick inputs and timings were collected, from which we could successfully reconstruct travel paths, input profiles and relative target displacements. Results: Subjects exhibited significant improvements in docking over the course of the experiment. Learning to compensate for roll-alterations was robust, whereas compensation for pitch-alterations was not in evidence in this population and relatively short training period. Conclusion: The SpaceDock platform can provide a novel method for training and testing subjects, on a spaceflight-relevant task, and can be used to examine behavioral learning, strategy use, and has been adapted for use in brain imaging experiments.

Nutritional Biochemistry of Spaceflight

NASA Technical Reports Server (NTRS)

Smith, Scott M.

2000-01-01

Adequate nutrition is critical for crew health and safety during spaceflight. To ensure adequate nutrition, the nutrient requirements need to be both accurate and available from the spaceflight food system. The existing nutritional requirements for extended-duration spaceflight have been defined largely by extrapolation from ground-based research. However, nutritional requirements are influenced by most of the physiological consequences of spaceflight, including loss of lean, adipose, and bone tissue; changes in blood composition; and increased risk of renal stone formation. This review focuses on key areas where information has been gained in recent years: dietary intake and energy metabolism, bone health, fluid and electrolyte homeostasis, and hematological changes. Areas in which specific nutrients have the potential to serve as countermeasures to the negative effects of spaceflight are also reviewed. Dietary Intake

Spaceflight and age affect tibial epiphyseal growth plate histomorphometry

NASA Technical Reports Server (NTRS)

Montufar-Solis, Dina; Duke, Pauline J.; Durnova, G.

1992-01-01

Growth plate histomorphometry of rats flown aboard the Soviet biosatellite Cosmos 2044, a 14-day spaceflight, was compared with that of control groups. In growth plates of flight animals, there was a significant increase in cell number per column and height of the proliferative zone and a reduction in height and cell number in the hypertrophy/calcification zone. No significant differences were found in matrix organization at the ultrastructural level of flight animals, indicating that although spacefligfht continues to affect bone growth of 15-wk-old rats, extracellular matrix is not altered in the same manner as seen previously in younger animals. All groups showed growth plate characteristics attributed to aging: lack of calcification zone, reduced hypertrophy zone, and unraveling of collagen fibrils. Tail-suspended controls did not differ from other controls in any of the parameters measured. The results suggest that growth plates of older rats are less responsive to unloading by spaceflight or suspension than those of younger rats and provide new evidence about the modifying effect of spaceflight on the growth plate.

Cardiovascular adaptation to spaceflight

NASA Technical Reports Server (NTRS)

Charles, John B.; Lathers, Claire M.

1991-01-01

Data are presented on the rate of adaptation of the human cardiovascular system to conditions of spaceflight, with particular attention given to data obtained during spaceflight in the U.S. Space Shuttle Program. It is pointed out that many of the cardiovascular changes that occurred during spaceflights that lasted from 2 to 11 days can be traced directly to changes in the body fluid volume. The beneficial effects of a fluid loading countermeasure (oral rehydration) and of the supine body position on the heart rate during the spaceflight are demonstrated. It is noted that, after hours or a few days of spaceflight, a state of adaptation is reached, in which the subject is well adapted and appropriately hydrated for the weightless environment. However, the return to the normal gravity of the earth leaves the individual especially sensitive to orthostatic stress.

Spaceflight and Neurosurgery: A Comprehensive Review of the Relevant Literature.

PubMed

Swinney, Christian C; Allison, Zain

2018-01-01

Spaceflight and the associated gravitational fluctuations may impact various components of the central nervous system. These include changes in intracranial pressure, the spine, and neurocognitive performance. The implications of altered astronaut performance on critical spaceflight missions are potentially significant. The current body of research on this important topic is extremely limited, and a comprehensive review has not been published. Herein, the authors address this notable gap, as well as the role of the neurosurgeon in optimizing potential diagnostic and therapeutic modalities. A literature search was conducted using the PubMed, EMBASE, and Google Scholar databases, with no time constraints. Significant manuscripts on physiologic changes associated with spaceflight and microgravity were identified and reviewed. Manifestations were separated into 1 of 3 general categories, including changes in intracranial pressure, the spine, and neurocognitive performance. A comprehensive literature review yielded 27 studies with direct relevance to the impact of microgravity and spaceflight on nervous system physiology. This included 7 studies related to intracranial pressure fluctuations, 17 related to changes in the spinal column, and 3 related to neurocognitive change. The microgravity environment encountered during spaceflight impacts intracranial physiology. This includes changes in intracranial pressure, the spinal column, and neurocognitive performance. Herein, we present a systematic review of the published literature on this issue. Neurosurgeons should have a key role in the continued study of this important topic, contributing to both diagnostic and therapeutic understanding. Copyright © 2017 Elsevier Inc. All rights reserved.

Phenotypic and gene expression responses of E. coli to antibiotics during spaceflight

NASA Astrophysics Data System (ADS)

Zea, Luis

Bacterial susceptibility to antibiotics has been shown in vitro to be reduced during spaceflight; however, the underlying mechanisms responsible for this outcome are not fully understood. In particular, it is not yet clear whether this observed response is due to increased drug resistance (a microbial defense response) or decreased drug efficacy (a microgravity biophysical mass transport effect). To gain insight into the differentiation between these two potential causes, an investigation was undertaken onboard the International Space Station (ISS) in 2014 termed Antibiotic Effectiveness in Space-1 (AES-1). For this purpose, E. coli was challenged with two antibiotics, Gentamicin Sulfate and Colistin Sulfate, at concentrations higher than those needed to inhibit growth on Earth. Phenotypic parameters (cell size, cell envelope thickness, population density and lag phase duration) and gene expression were compared between the spaceflight samples and ground controls cultured in varying levels of drug concentration. It was observed that flight samples proliferated in antibiotic concentrations that were inhibitory on Earth, growing on average to a 13-fold greater concentration than matched 1g controls. Furthermore, at the highest drug concentrations in space, E. coli cells were observed to aggregate into visible clusters. In spaceflight, cell size was significantly reduced, translating to a decrease in cell surface area to about one half of the ground controls. Smaller cell surface area can in turn proportionally reduce the rate of antibiotic molecules reaching the cell. Additionally, it was observed that genes --- in some cases more than 2000 --- were overexpressed in space with respect to ground controls. Up-regulated genes include poxB, which helps catabolize glucose into organic acids that alter acidity around and inside the cell, and the gadABC family genes, which confer resistance to extreme acid conditions. The next step is to characterize the mechanisms behind

Reduced heart rate variability during sleep in long-duration spaceflight.

PubMed

Xu, D; Shoemaker, J K; Blaber, A P; Arbeille, P; Fraser, K; Hughson, R L

2013-07-15

Limited data are available to describe the regulation of heart rate (HR) during sleep in spaceflight. Sleep provides a stable supine baseline during preflight Earth recordings for comparison of heart rate variability (HRV) over a wide range of frequencies using both linear, complexity, and fractal indicators. The current study investigated the effect of long-duration spaceflight on HR and HRV during sleep in seven astronauts aboard the International Space Station up to 6 mo. Measurements included electrocardiographic waveforms from Holter monitors and simultaneous movement records from accelerometers before, during, and after the flights. HR was unchanged inflight and elevated postflight [59.6 ± 8.9 beats per minute (bpm) compared with preflight 53.3 ± 7.3 bpm; P < 0.01]. Compared with preflight data, HRV indicators from both time domain and power spectral analysis methods were diminished inflight from ultralow to high frequencies and partially recovered to preflight levels after landing. During inflight and at postflight, complexity and fractal properties of HR were not different from preflight properties. Slow fluctuations (<0.04 Hz) in HR presented moderate correlations with movements during sleep, partially accounting for the reduction in HRV. In summary, substantial reduction in HRV was observed with linear, but not with complexity and fractal, methods of analysis. These results suggest that periodic elements that influence regulation of HR through reflex mechanisms are altered during sleep in spaceflight but that underlying system complexity and fractal dynamics were not altered.

Overview of spaceflight immunology studies

NASA Technical Reports Server (NTRS)

Taylor, G. R.

1993-01-01

The effects of spaceflight and analogues of spaceflight are discussed here and in nine accompanying articles. In this summary we present spaceflight studies with human subjects, animal subjects, and cell cultures and we review ground-based systems used to model the observed effects of spaceflight on the immune system. Human paradigms include bed rest, academic or psychological stress, physical stress, hypobaric or high altitude stress, and confinement. Animal models include antiorthostatic and orthostatic suspension, hypobarism, and confinement. The ten manuscripts in this collection were selected to provide a summary that should give the reader an overview of the various activities of spaceflight immunology researchers throughout the history of space travel. This manuscript identifies the major contributors to the study of spaceflight immunology, explains what types of studies have been conducted, and how they have changed over the years. Also presented is a discussion of the unusual limitations associated with spaceflight research and the efforts to develop appropriate ground-based surrogate model systems. Specific details, data, and mechanistic speculations will be held to a minimum, because they will be discussed in depth in the other articles in the collection.

Animals and spaceflight: from survival to understanding.

PubMed

Morey-Holton, E R; Hill, E L; Souza, K A

2007-01-01

Animals have been a critical component of the spaceflight program since its inception. The Russians orbited a dog one month after the Sputnik satellite was launched. The dog mission spurred U.S. interest in animal flights. The animal missions proved that individuals aboard a spacecraft not only could survive, but also could carry out tasks during launch, near-weightlessness, and re-entry; humans were launched into space only after the early animal flights demonstrated that spaceflight was safe and survivable. After these humble beginnings when animals preceded humans in space as pioneers, a dynamic research program was begun using animals as human surrogates aboard manned and unmanned space platforms to understand how the unique environment of space alters life. In this review article, the following questions have been addressed: How did animal research in space evolve? What happened to animal development when gravity decreased? How have animal experiments in space contributed to our understanding of musculoskeletal changes and fracture repair during exposure to reduced gravity?

Spaceflight and clinorotation cause cytoskeleton and mitochondria changes and increases in apoptosis in cultured cells

NASA Technical Reports Server (NTRS)

Schatten, H.; Lewis, M. L.; Chakrabarti, A.

2001-01-01

The cytoskeleton is a complex network of fibers that is sensitive to environmental factors including microgravity and altered gravitational forces. Cellular functions such as transport of cell organelles depend on cytoskeletal integrity; regulation of cytoskeletal activity plays a role in cell maintenance, cell division, and apoptosis. Here we report cytoskeletal and mitochondria alterations in cultured human lymphocyte (Jurkat) cells after exposure to spaceflight and in insect cells of Drosophila melanogaster (Schneider S-1) after exposure to conditions created by clinostat rotation. Jurkat cells were flown on the space shuttle in Biorack cassettes while Schneider S-1 cells were exposed to altered gravity forces as produced by clinostat rotation. The effects of both treatments were similar in the different cell types. Fifty percent of cells displayed effects on the microtubule network in both cell lines. Under these experimental conditions mitochondria clustering and morphological alterations of mitochondrial cristae was observed to various degrees after 4 and 48 hours of culture. Jurkat cells underwent cell divisions during exposure to spaceflight but a large number of apoptotic cells was also observed. Similar results were obtained in Schneider S-1 cells cultured under clinostat rotation. Both cell lines displayed mitochondria abnormalities and mitochondria clustering toward one side of the cells which is interpreted to be the result of microtubule disruption and failure of mitochondria transport along microtubules. The number of mitochondria was increased in cells exposed to altered gravity while cristae morphology was severely affected indicating altered mitochondria function. These results show that spaceflight as well as altered gravity produced by clinostat rotation affects microtubule and mitochondria organization and results in increases in apoptosis. Grant numbers: NAG 10-0224, NAG2-985. c 2001. Elsevier Science Ltd. All rights reserved.

Spaceflight-Induced Intracranial Hypertension and Visual Impairment: Pathophysiology and Countermeasures.

PubMed

Zhang, Li-Fan; Hargens, Alan R

2018-01-01

Visual impairment intracranial pressure (VIIP) syndrome is considered an unexplained major risk for future long-duration spaceflight. NASA recently redefined this syndrome as Spaceflight-Associated Neuro-ocular Syndrome (SANS). Evidence thus reviewed supports that chronic, mildly elevated intracranial pressure (ICP) in space (as opposed to more variable ICP with posture and activity on Earth) is largely accounted for by loss of hydrostatic pressures and altered hemodynamics in the intracranial circulation and the cerebrospinal fluid system. In space, an elevated pressure gradient across the lamina cribrosa, caused by a chronic but mildly elevated ICP, likely elicits adaptations of multiple structures and fluid systems in the eye which manifest themselves as the VIIP syndrome. A chronic mismatch between ICP and intraocular pressure (IOP) in space may acclimate the optic nerve head, lamina cribrosa, and optic nerve subarachnoid space to a condition that is maladaptive to Earth, all contributing to the pathogenesis of space VIIP syndrome. Relevant findings help to evaluate whether artificial gravity is an appropriate countermeasure to prevent this seemingly adverse effect of long-duration spaceflight. Copyright © 2018 the American Physiological Society.

Dammarane Sapogenins Ameliorates Neurocognitive Functional Impairment Induced by Simulated Long-Duration Spaceflight.

PubMed

Wu, Xiaorui; Li, Dong; Liu, Junlian; Diao, Lihong; Ling, Shukuan; Li, Yuheng; Gao, Jianyi; Fan, Quanchun; Sun, Weijia; Li, Qi; Zhao, Dingsheng; Zhong, Guohui; Cao, Dengchao; Liu, Min; Wang, Jiaping; Zhao, Shuang; Liu, Yu; Bai, Guie; Shi, Hongzhi; Xu, Zi; Wang, Jing; Xue, Chunmei; Jin, Xiaoyan; Yuan, Xinxin; Li, Hongxing; Liu, Caizhi; Sun, Huiyuan; Li, Jianwei; Li, Yongzhi; Li, Yingxian

2017-01-01

Increasing evidence indicates the occurrence of cognitive impairment in astronauts under spaceflight compound conditions, but the underlying mechanisms and countermeasures need to be explored. In this study, we found that learning and memory abilities were significantly reduced in rats under a simulated long-duration spaceflight environment (SLSE), which includes microgravity, isolation confinement, noises, and altered circadian rhythms. Dammarane sapogenins (DS), alkaline hydrolyzed products of ginsenosides, can enhance cognition function by regulating brain neurotransmitter levels and inhibiting SLSE-induced neuronal injury. Bioinformatics combined with experimental verification identified that the PI3K-Akt-mTOR pathway was inhibited and the MAPK pathway was activated during SLSE-induced cognition dysfunction, whereas DS substantially ameliorated the changes in brain. These findings defined the characteristics of SLSE-induced cognitive decline and the mechanisms by which DS improves it. The results provide an effective candidate for improving cognitive function in spaceflight missions.

Dammarane Sapogenins Ameliorates Neurocognitive Functional Impairment Induced by Simulated Long-Duration Spaceflight

PubMed Central

Wu, Xiaorui; Li, Dong; Liu, Junlian; Diao, Lihong; Ling, Shukuan; Li, Yuheng; Gao, Jianyi; Fan, Quanchun; Sun, Weijia; Li, Qi; Zhao, Dingsheng; Zhong, Guohui; Cao, Dengchao; Liu, Min; Wang, Jiaping; Zhao, Shuang; Liu, Yu; Bai, Guie; Shi, Hongzhi; Xu, Zi; Wang, Jing; Xue, Chunmei; Jin, Xiaoyan; Yuan, Xinxin; Li, Hongxing; Liu, Caizhi; Sun, Huiyuan; Li, Jianwei; Li, Yongzhi; Li, Yingxian

2017-01-01

Increasing evidence indicates the occurrence of cognitive impairment in astronauts under spaceflight compound conditions, but the underlying mechanisms and countermeasures need to be explored. In this study, we found that learning and memory abilities were significantly reduced in rats under a simulated long-duration spaceflight environment (SLSE), which includes microgravity, isolation confinement, noises, and altered circadian rhythms. Dammarane sapogenins (DS), alkaline hydrolyzed products of ginsenosides, can enhance cognition function by regulating brain neurotransmitter levels and inhibiting SLSE-induced neuronal injury. Bioinformatics combined with experimental verification identified that the PI3K-Akt-mTOR pathway was inhibited and the MAPK pathway was activated during SLSE-induced cognition dysfunction, whereas DS substantially ameliorated the changes in brain. These findings defined the characteristics of SLSE-induced cognitive decline and the mechanisms by which DS improves it. The results provide an effective candidate for improving cognitive function in spaceflight missions. PMID:28611667

Effect of spaceflight on the isotonic contractile properties of single skeletal muscle fibers in the rhesus monkey

NASA Technical Reports Server (NTRS)

Fitts, R. H.; Romatowski, J. G.; Blaser, C.; De La Cruz, L.; Gettelman, G. J.; Widrick, J. J.

2000-01-01

Experiments from both Cosmos and Space Shuttle missions have shown weightlessness to result in a rapid decline in the mass and force of rat hindlimb extensor muscles. Additionally, despite an increased maximal shortening velocity, peak power was reduced in rat soleus muscle post-flight. In humans, declines in voluntary peak isometric ankle extensor torque ranging from 15-40% have been reported following long- and short-term spaceflight and prolonged bed rest. Complete understanding of the cellular events responsible for the fiber atrophy and the decline in force, as well as the development of effective countermeasures, will require detailed knowledge of how the physiological and biochemical processes of muscle function are altered by spaceflight. The specific purpose of this investigation was to determine the extent to which the isotonic contractile properties of the slow- and fast-twitch fiber types of the soleus and gastrocnemius muscles of rhesus monkeys (Macaca mulatta) were altered by a 14-day spaceflight.

Development of an Integrated Sensorimotor Countermeasure Suite for Spaceflight Operations

NASA Technical Reports Server (NTRS)

Bloomberg, J. J.; Batson, C. D.; Caldwell, E. E. (Inventor); Feiveson, A. H.; Kreutzberg, G. A.; Miller, C. A.; Mulavara, A. P.; Oddsson, L. I. E.; Peters, B. T.; Ploutz-Synder, L. L.;

Structural alterations of faecal and mucosa-associated bacterial communities in irritable bowel syndrome.

PubMed

Durbán, Ana; Abellán, Juan J; Jiménez-Hernández, Nuria; Salgado, Patricia; Ponce, Marta; Ponce, Julio; Garrigues, Vicente; Latorre, Amparo; Moya, Andrés

2012-04-01

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder in western countries. Previous studies on IBS, mostly based on faecal samples, suggest alterations in the intestinal microbiota. However, no consensus has been reached regarding the association between specific bacteria and IBS. We explore the alterations of intestinal bacterial communities in IBS using massive sequencing of amplified 16S rRNA genes. Mucosal biopsies of the ascending and descending colon and faeces from 16 IBS patients and 9 healthy controls were analysed. Strong inter-individual variation was observed in the composition of the bacterial communities in both patients and controls. These communities showed less diversity in IBS cases. There were larger differences in the microbiota composition between biopsies and faeces than between patients and controls. We found a few over-represented and under-represented taxa in IBS cases with respect to controls. The detected alterations varied by site, with no changes being consistent across sample types. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

Spaceflight Effects on Neurocognitive Performance: Extent, Longevity and Neural Bases

NASA Technical Reports Server (NTRS)

Seidler, R. D.; Mulavara, A. P.; Koppelmans, V.; Kofman, I. S.; Cassady, K.; Yuan, P.; De Dios, Y. E.; Gadd, N.; Riascos, R. F.; Wood, S. J.;

BRIC-21: Global Transcriptome Profiling to Identify Cellular Stress Mechanisms Responsible for Spaceflight-Induced Antibiotic Resistance

NASA Technical Reports Server (NTRS)

Nicholson, Wayne L.; Fajardo-Cavazos, Patricia

2015-01-01

Comparisons of spaceflight stress responses in Bacillus subtilis spores and Staphylococcus epidermidis cells to ground-based controls will be conducted to uncover alterations in their antibiotic susceptibility.

Spaceflight and ageing: reflecting on Caenorhabditis elegans in space.

PubMed

Honda, Yoko; Honda, Shuji; Narici, Marco; Szewczyk, Nathaniel J

2014-01-01

The prospect of space travel continues to capture the imagination. Several competing companies are now promising flights for the general population. Previously, it was recognized that many of the physiological changes that occur with spaceflight are similar to those seen with normal ageing. This led to the notion that spaceflight can be used as a model of accelerated ageing and raised concerns about the safety of individuals engaging in space travel. Paradoxically, however, space travel has been recently shown to be beneficial to some aspects of muscle health in the tiny worm Caenorhabditis elegans. C. elegans is a commonly used laboratory animal for studying ageing. C. elegans displays age-related decline of some biological processes observed in ageing humans, and about 35% of C. elegans' genes have human homologs. Space flown worms were found to have decreased expression of a number of genes that increase lifespan when expressed at lower levels. These changes were accompanied by decreased accumulation of toxic protein aggregates in ageing worms' muscles. Thus, in addition to spaceflight producing physiological changes that are similar to accelerated ageing, it also appears to produce some changes similar to delayed ageing. Here, we put forward the hypothesis that in addition to the previously well-appreciated mechanotransduction changes, neural and endocrine signals are altered in response to spaceflight and that these may have both negative (e.g. less muscle protein) and some positive consequences (e.g. healthier muscles), at least for invertebrates, with respect to health in space. Given that changes in circulating hormones are well documented with age and in astronauts, our view is that further research into the relationship between metabolic control, ageing, and adaptation to the environment should be productive in advancing our understanding of the physiology of both spaceflight and ageing.

Analysis of Cell Proliferation in Newt (Pleurodeles waltl) Tissue Regeneration during Spaceflight in Foton M-2

NASA Technical Reports Server (NTRS)

Almeida, E. A. C.; Roden, C.; Phillips, J. A.; Yusuf, R.; Globus, R. K.; Searby, N.; Vercoutere, W.; Morey-Holton, E.; Tairbekov, M.; Grigoryan, N.;

Cultivation in space flight produces minimal alterations in the susceptibility of Bacillus subtilis cells to 72 different antibiotics and growth-inhibiting compounds.

PubMed

Morrison, Michael D; Fajardo-Cavazos, Patricia; Nicholson, Wayne L

2017-08-18

Past results have suggested that bacterial antibiotic susceptibility is altered during space flight. To test this notion, Bacillus subtilis cells were cultivated in matched hardware, medium, and environmental conditions either in spaceflight microgravity on the International Space Station, termed Flight (FL) samples, or at Earth-normal gravity, termed Ground Control (GC) samples. Susceptibility of FL and GC samples was compared to 72 antibiotics and growth-inhibitory compounds using the Omnilog Phenotype Microarray (PM) system. Only 9 compounds were identified by PM screening as exhibiting significant differences ( P < 0.05, Student's t-test) in FL vs. GC samples: 6-mercaptopurine, cesium chloride, enoxacin, lomefloxacin, manganese (II) chloride, nalidixic acid, penimepicycline, rolitetracycline, and trifluoperazine. Testing of the same compounds by standard broth dilution assay did not reveal statistically significant differences in the IC 50 values between FL and GC samples. The results indicate that the susceptibility of B. subtilis cells to a wide range of antibiotics and growth inhibitors is not dramatically altered by space flight. Importance: This study addresses a major concern of mission planners for human spaceflight, that bacteria accompanying astronauts on long-duration missions might develop a higher level of resistance to antibiotics due to exposure to the spaceflight environment. The results of this study do not support that notion. Copyright © 2017 American Society for Microbiology.

Fertilization Shapes Bacterial Community Structure by Alteration of Soil pH.

PubMed

Zhang, Yuting; Shen, Hong; He, Xinhua; Thomas, Ben W; Lupwayi, Newton Z; Hao, Xiying; Thomas, Matthew C; Shi, Xiaojun

2017-01-01

Application of chemical fertilizer or manure can affect soil microorganisms directly by supplying nutrients and indirectly by altering soil pH. However, it remains uncertain which effect mostly shapes microbial community structure. We determined soil bacterial diversity and community structure by 454 pyrosequencing the V1-V3 regions of 16S rRNA genes after 7-years (2007-2014) of applying chemical nitrogen, phosphorus and potassium (NPK) fertilizers, composted manure or their combination to acidic (pH 5.8), near-neutral (pH 6.8) or alkaline (pH 8.4) Eutric Regosol soil in a maize-vegetable rotation in southwest China. In alkaline soil, nutrient sources did not affect bacterial Operational Taxonomic Unit (OTU) richness or Shannon diversity index, despite higher available N, P, K, and soil organic carbon in fertilized than in unfertilized soil. In contrast, bacterial OTU richness and Shannon diversity index were significantly lower in acidic and near-neutral soils under NPK than under manure or their combination, which corresponded with changes in soil pH. Permutational multivariate analysis of variance showed that bacterial community structure was significantly affected across these three soils, but the PCoA ordination patterns indicated the effect was less distinct among nutrient sources in alkaline than in acidic and near-neural soils. Distance-based redundancy analysis showed that bacterial community structures were significantly altered by soil pH in acidic and near-neutral soils, but not by any soil chemical properties in alkaline soil. The relative abundance (%) of most bacterial phyla was higher in near-neutral than in acidic or alkaline soils. The most dominant phyla were Proteobacteria (24.6%), Actinobacteria (19.7%), Chloroflexi (15.3%) and Acidobacteria (12.6%); the medium dominant phyla were Bacterioidetes (5.3%), Planctomycetes (4.8%), Gemmatimonadetes (4.5%), Firmicutes (3.4%), Cyanobacteria (2.1%), Nitrospirae (1.8%), and candidate division TM7 (1

Post-spaceflight orthostatic intolerance: possible relationship to microgravity-induced plasticity in the vestibular system

NASA Technical Reports Server (NTRS)

Yates, B. J.; Kerman, I. A.

1998-01-01

Even after short spaceflights, most astronauts experience at least some postflight reduction of orthostatic tolerance; this problem is severe in some subjects. The mechanisms leading to postflight orthostatic intolerance are not well-established, but have traditionally been thought to include the following: changes in leg hemodynamics, alterations in baroreceptor reflex gain, decreases in exercise tolerance and aerobic fitness, hypovolemia, and altered sensitivity of beta-adrenergic receptors in the periphery. Recent studies have demonstrated that signals from vestibular otolith organs play an important role in regulating blood pressure during changes in posture in a 1-g environment. Because spaceflight results in plastic changes in the vestibular otolith organs and in the processing of inputs from otolith receptors, it is possible that another contributing factor to postflight orthostatic hypotension is alterations in the gain of vestibular influences on cardiovascular control. Preliminary data support this hypothesis, although controlled studies will be required to determine the relationship between changes in the vestibular system and orthostatic hypotension following exposure to microgravity. Copyright 1998 Elsevier Science B.V.

Defending spaceflight: The echoes of Apollo

NASA Astrophysics Data System (ADS)

Rovetto, R. J.

2016-12-01

This paper defends, and emphasizes the importance of, spaceflight, broadly construed to include human and unmanned spaceflight, space science, exploration and development. Within this discourse, I provide counter-replies to remarks by physicist Dr. Steven Weinberg against my previous support of human spaceflight. In this defense of peaceful spaceflight I draw upon a variety of sources. Although a focus is human spaceflight, human and unmanned modes must not be treated as an either-or opposition. Rather, each has a critical role to play in moving humanity forward as a spacefaring species. In the course of this communication, I also stress the perennial role of space agencies as science and technology-drivers, and their function to provide a stable and unified platform for space programs.

Effects of the hindlimb-unloading model of spaceflight conditions on resistance of mice to infection with Klebsiella pneumoniae

NASA Technical Reports Server (NTRS)

Belay, Tesfaye; Aviles, Hernan; Vance, Monique; Fountain, Kimberly; Sonnenfeld, Gerald

2002-01-01

BACKGROUND: It has been well documented in several studies that many immunologic parameters are altered in experimental animals and human subjects who have flown in space. However, it is not fully known whether these immunologic changes could result in increased susceptibility to infection. Hindlimb (antiorthostatic) unloading of rodents has been used successfully to simulate some of the effects of spaceflight on physiologic systems. OBJECTIVE: The objective of this study was to determine the effect of hindlimb unloading on the outcome of Klebsiella pneumoniae infection in mice. METHODS: Hindlimb-unloaded, hindlimb-restrained, and control mice were intraperitoneally infected with one 50% lethal dose of K pneumoniae 2 days after suspension. Mortality and bacterial load in several organs were compared among the groups. RESULTS: Unloaded mice showed significantly increased mortality and reduced mean time to death compared with that seen in the control groups. Kinetics of bacterial growth with smaller infective doses revealed that control mice were able to clear bacteria from the organs after 30 hours. In contrast, unloaded mice had continued bacterial growth at the same time point. CONCLUSION: The results of this study suggest that hindlimb unloading might enhance the dissemination of K pneumoniae, leading to increased mortality. The complex physiologic changes observed during hindlimb unloading, including stress, have a key role in the pathophysiology of this infection.

Effects of a spaceflight analog environment on brain connectivity and behavior.

PubMed

Cassady, Kaitlin; Koppelmans, Vincent; Reuter-Lorenz, Patricia; De Dios, Yiri; Gadd, Nichole; Wood, Scott; Castenada, Roy Riascos; Kofman, Igor; Bloomberg, Jacob; Mulavara, Ajitkumar; Seidler, Rachael

2016-11-01

Sensorimotor functioning is adaptively altered following long-duration spaceflight. The question of whether microgravity affects other central nervous system functions such as brain network organization and its relationship with behavior is largely unknown, but of importance to the health and performance of astronauts both during and post-flight. In the present study, we investigate the effects of prolonged exposure to an established spaceflight analog on resting state brain functional connectivity and its association with behavioral changes in 17 male participants. These bed rest participants remained in bed with their heads tilted down six degrees below their feet for 70 consecutive days. Resting state functional magnetic resonance imaging (rs-fMRI) and behavioral data were obtained at seven time points averaging around: 12 and 8days prior to bed rest; 7, 50, and 70days during bed rest; and 8 and 12days after bed rest. To assess potential confounding effects due to scanning interval or task practice, we also acquired rs-fMRI and behavioral measurements from 14 control participants at four time points. 70days of head-down tilt (HDT) bed rest resulted in significant changes in the functional connectivity of motor, somatosensory, and vestibular areas of the brain. Moreover, several of these network alterations were significantly associated with changes in sensorimotor and spatial working memory performance, which suggests that neuroplasticity mechanisms may facilitate adaptation to the microgravity analog environment. The findings from this study provide novel insights into the underlying neural mechanisms and operational risks of spaceflight analog-related changes in sensorimotor performance. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects and Responses to Spaceflight in the Mouse Retina

NASA Technical Reports Server (NTRS)

Zanello, Susana B.; Theriot, Corey; Westby, Christian; Boyle, Richard

2011-01-01

Several stress environmental factors are combined in a unique fashion during spaceflight, affecting living beings widely across their physiological systems. Recently, attention has been placed on vision changes in astronauts returning from long duration missions. Alterations include hyperoptic shift, globe flattening, choroidal folds and optic disc edema, which are probably associated with increased intracranial pressure. These observations justify a better characterization of the ocular health risks associated with spaceflight. This study investigates the impact of spaceflight on the biology of the mouse retina. Within a successful tissue sharing effort, eyes from albino Balb/cJ mice aboard STS-133 were collected for histological analysis and gene expression profiling of the retina at 1 and 7 days after landing. Both vivarium and AEM (Animal Enclosure Module) mice were used as ground controls. Oxidative stress-induced DNA damage was higher in the flight samples compared to controls on R+1, and decreased on R+7. A trend toward higher oxidative and cellular stress response gene expression was also observed on R+1 compared to AEM controls, and these levels decreased on R+7. Several genes coding for key antioxidant enzymes, namely, heme-oxygenase-1, peroxiredoxin, and catalase, were among those upregulated after flight. Likewise, NF B and TGFbeta1, were upregulated in one flight specimen that overall showed the most elevated oxidative stress markers on R+1. In addition, retinas from vivarium control mice evidenced higher oxidative stress markers, NF B and TGFbeta1, likely due to the more intense illumination in vivarium cages versus the AEM. These preliminary data suggest that spaceflight represents a source of environmental stress that translates into oxidative and cellular stress in the retina, which is partially reversible upon return to Earth. Further work is needed to dissect the contribution of the various spaceflight factors (microgravity, radiation) and to

Genitourinary issues during spaceflight: a review.

PubMed

Jones, J A; Jennings, R; Pietryzk, R; Ciftcioglu, N; Stepaniak, P

2005-12-01

The genitourinary (GU) system is not uncommonly affected during previous spaceflights. GU issues that have been observed during spaceflight include urinary calculi, infections, retention, waste management, and reproductive. In-flight countermeasures for each of these issues are being developed to reduce the likelihood of adverse sequelae, due to GU issues during exploration-class spaceflight, to begin in 2018 with flights back to the Moon and on to Mars, according to the February 2004 Presendent's Vision for US Space Exploration. With implementation of a robust countermeasures program, GU issues should not have a significant threat for mission impact during future spaceflights.

Spaceflight of HUVEC: An Integrated eXperiment- SPHINX Onboard the ISS

NASA Astrophysics Data System (ADS)

Versari, S.; Maier, J. A. M.; Norfini, A.; Zolesi, V.; Bradamante, S.

2013-02-01

The spaceflight orthostatic challenge can promote in astronauts inadequate cardiovascular responses defined as cardiovascular deconditioning. In particular, disturbance of endothelial functions are known to lead to altered vascular performances, being the endothelial cells crucial in the maintenance of the functional integrity of the vascular wall. In order to evaluate whether weightlessness affects endothelial functions, we designed, developed, and performed the experiment SPHINX - SPaceflight of HUVEC: an INtegrated eXperiment - where HUVEC (Human Umbilical Vein Endothelial Cells) were selected as a macrovascular cell model system. SPHINX arrived at the International Space Station (ISS) onboard Progress 40P, and was processed inside Kubik 6 incubator for 7 days. At the end, all of the samples were suitably fixed and preserved at 6°C until return on Earth on Soyuz 23S.

Molecular aspects of stress-gene regulation during spaceflight

NASA Technical Reports Server (NTRS)

Paul, Anna-Lisa; Ferl, Robert J.

2002-01-01

Spaceflight-associated stress has been the topic of investigation since the first terrestrial organisms were exposed to this unique environment. Organisms that evolved under the selection pressures of earth-normal environments can perceive spaceflight as a stress, either directly because gravity influences an intrinsic biological process, or indirectly because of secondary effects imparted by spaceflight upon environmental conditions. Different organisms and even different organs within an organism adapt to a spaceflight environment with a diversity of tactics. Plants are keenly sensitive to gravity for directed development, and are also sensitive to other stresses associated with closed-system spaceflight environments. Within the past decade, the tools of molecular biology have begun to provide a sophisticated evaluation of spaceflight-associated stress and the genetic responses that accompany metabolic adaptation to spaceflight.

Canopy soil bacterial communities altered by severing host tree limbs

PubMed Central

Dangerfield, Cody R.; Nadkarni, Nalini M.

2017-01-01

Trees of temperate rainforests host a large biomass of epiphytic plants, which are associated with soils formed in the forest canopy. Falling of epiphytic material results in the transfer of carbon and nutrients from the canopy to the forest floor. This study provides the first characterization of bacterial communities in canopy soils enabled by high-depth environmental sequencing of 16S rRNA genes. Canopy soil included many of the same major taxonomic groups of Bacteria that are also found in ground soil, but canopy bacterial communities were lower in diversity and contained different operational taxonomic units. A field experiment was conducted with epiphytic material from six Acer macrophyllum trees in Olympic National Park, Washington, USA to document changes in the bacterial communities of soils associated with epiphytic material that falls to the forest floor. Bacterial diversity and composition of canopy soil was highly similar, but not identical, to adjacent ground soil two years after transfer to the forest floor, indicating that canopy bacteria are almost, but not completely, replaced by ground soil bacteria. Furthermore, soil associated with epiphytic material on branches that were severed from the host tree and suspended in the canopy contained altered bacterial communities that were distinct from those in canopy material moved to the forest floor. Therefore, the unique nature of canopy soil bacteria is determined in part by the host tree and not only by the physical environmental conditions associated with the canopy. Connection to the living tree appears to be a key feature of the canopy habitat. These results represent an initial survey of bacterial diversity of the canopy and provide a foundation upon which future studies can more fully investigate the ecological and evolutionary dynamics of these communities. PMID:28894646

Canopy soil bacterial communities altered by severing host tree limbs.

PubMed

Dangerfield, Cody R; Nadkarni, Nalini M; Brazelton, William J

2017-01-01

Trees of temperate rainforests host a large biomass of epiphytic plants, which are associated with soils formed in the forest canopy. Falling of epiphytic material results in the transfer of carbon and nutrients from the canopy to the forest floor. This study provides the first characterization of bacterial communities in canopy soils enabled by high-depth environmental sequencing of 16S rRNA genes. Canopy soil included many of the same major taxonomic groups of Bacteria that are also found in ground soil, but canopy bacterial communities were lower in diversity and contained different operational taxonomic units. A field experiment was conducted with epiphytic material from six Acer macrophyllum trees in Olympic National Park, Washington, USA to document changes in the bacterial communities of soils associated with epiphytic material that falls to the forest floor. Bacterial diversity and composition of canopy soil was highly similar, but not identical, to adjacent ground soil two years after transfer to the forest floor, indicating that canopy bacteria are almost, but not completely, replaced by ground soil bacteria. Furthermore, soil associated with epiphytic material on branches that were severed from the host tree and suspended in the canopy contained altered bacterial communities that were distinct from those in canopy material moved to the forest floor. Therefore, the unique nature of canopy soil bacteria is determined in part by the host tree and not only by the physical environmental conditions associated with the canopy. Connection to the living tree appears to be a key feature of the canopy habitat. These results represent an initial survey of bacterial diversity of the canopy and provide a foundation upon which future studies can more fully investigate the ecological and evolutionary dynamics of these communities.

Spaceflight bioreactor studies of cells and tissues.

PubMed

Freed, Lisa E; Vunjak-Novakovic, Gordana

2002-01-01

Studies of the fundamental role of gravity in the development and function of biological organisms are a central component of the human exploration of space. Microgravity affects numerous physical phenomena relevant to biological research, including the hydrostatic pressure in fluid filled vesicles, sedimentation of organelles, and buoyancy-driven convection of flow and heat. These physical phenomena can in turn directly and indirectly affect cellular morphology, metabolism, locomotion, secretion of extracellular matrix and soluble signals, and assembly into functional tissues. Studies aimed at distinguishing specific effects of gravity on biological systems require the ability to: (i) control and systematically vary gravity, e.g. by utilizing the microgravity environment of space in conjunction with an in-flight centrifuge; and (ii) maintain constant all other factors in the immediate environment, including in particular concentrations and exchange rates of biochemical species and hydrodynamic shear. The latter criteria imply the need for gravity-independent mechanisms to provide for mass transport between the cells and their environment. Available flight hardware has largely determined the experimental design and scientific objectives of spaceflight cell and tissue culture studies carried out to date. Simple culture vessels have yielded important quantitative data, and helped establish in vitro models of cell locomotion, growth and differentiation in various mammalian cell types including embryonic lung cells [6], lymphocytes [2,8], and renal cells [7,31]. Studies done using bacterial cells established the first correlations between gravity-dependent factors such as cell settling velocity and diffusional distance and the respective cell responses [12]. The development of advanced bioreactors for microgravity cell and tissue culture and for tissue engineering has benefited both research areas and provided relevant in vitro model systems for studies of astronaut

Spaceflight-induced cardiovascular changes and recovery during NASA's Functional Task Test

NASA Astrophysics Data System (ADS)

Arzeno, Natalia M.; Stenger, Michael B.; Bloomberg, Jacob J.; Platts, Steven H.

2013-11-01

Microgravity-induced physiologic changes could impair a crewmember's performance upon return to a gravity environment. The Functional Task Test aims to correlate these physiologic alterations with changes in performance during mission-critical tasks. In this study, we evaluated spaceflight-induced cardiovascular changes during 11 functional tasks in 7 Shuttle astronauts before spaceflight, on landing day, and 1, 6, and 30 days after landing. Mean heart rate was examined during each task and autonomic activity was approximated by heart rate variability during the Recovery from Fall/Stand Test, a 2-min prone rest followed by a 3-min stand. Heart rate was increased on landing day during all of the tasks, and remained elevated 6 days after landing during 6 of the 11 tasks. Parasympathetic modulation was diminished and sympathovagal balance was increased on landing day. Additionally, during the stand test 6 days after landing, parasympathetic modulation remained suppressed and heart rate remained elevated compared to preflight levels. Heart rate and autonomic activity were not different from preflight levels 30 days after landing. We detected changes in heart rate and autonomic activity during a 3-min stand and a variety of functional tasks, where cardiovascular deconditioning was still evident 6 days after returning from short-duration spaceflight. The delayed recovery times for heart rate and parasympathetic modulation indicate the necessity of assessing functional performance after long-duration spaceflight to ensure crew health and safety.

Design of a spaceflight biofilm experiment

NASA Astrophysics Data System (ADS)

Zea, Luis; Nisar, Zeena; Rubin, Phil; Cortesão, Marta; Luo, Jiaqi; McBride, Samantha A.; Moeller, Ralf; Klaus, David; Müller, Daniel; Varanasi, Kripa K.; Muecklich, Frank; Stodieck, Louis

2018-07-01

Biofilm growth has been observed in Soviet/Russian (Salyuts and Mir), American (Skylab), and International (ISS) Space Stations, sometimes jeopardizing key equipment like spacesuits, water recycling units, radiators, and navigation windows. Biofilm formation also increases the risk of human illnesses and therefore needs to be well understood to enable safe, long-duration, human space missions. Here, the design of a NASA-supported biofilm in space project is reported. This new project aims to characterize biofilm inside the International Space Station in a controlled fashion, assessing changes in mass, thickness, and morphology. The space-based experiment also aims at elucidating the biomechanical and transcriptomic mechanisms involved in the formation of a "column-and-canopy" biofilm architecture that has previously been observed in space. To search for potential solutions, different materials and surface topologies will be used as the substrata for microbial growth. The adhesion of bacteria to surfaces and therefore the initial biofilm formation is strongly governed by topographical surface features of about the bacterial scale. Thus, using Direct Laser-Interference Patterning, some material coupons will have surface patterns with periodicities equal, above or below the size of bacteria. Additionally, a novel lubricant-impregnated surface will be assessed for potential Earth and spaceflight anti-biofilm applications. This paper describes the current experiment design including microbial strains and substrata materials and nanotopographies being considered, constraints and limitations that arise from performing experiments in space, and the next steps needed to mature the design to be spaceflight-ready.

Skeletal changes during and after spaceflight.

PubMed

Vico, Laurence; Hargens, Alan

2018-03-21

Space sojourns are challenging for life. The ability of the human body to adapt to these extreme conditions has been noted since the beginning of human space travel. Skeletal alterations that occur during spaceflight are now better understood owing to tools such as dual-energy X-ray densitometry and high-resolution peripheral quantitative CT, and murine models help researchers to understand cellular and matrix changes that occur in bone and that are difficult to measure in humans. However, questions remain with regard to bone adaptation and osteocyte fate, as well as to interactions of the skeleton with fluid shifts towards the head and with the vascular system. Further investigations into the relationships between the musculoskeletal system, energy metabolism and sensory motor acclimatisation are needed. In this regard, an integrated intervention is required that will address multiple systems simultaneously. Importantly, radiation and isolation-related stresses are gaining increased attention as the prospect of human exploration into deep space draws nearer. Although space is a unique environment, clear parallels exist between the effects of spaceflight, periods of immobilization and ageing, with possibly irreversible features. Space travel offers an opportunity to establish integrated deconditioning and ageing interventions that combine nutritional, physical and pharmaceutical strategies.

Quantitative histochemistry of rat lumbar vertebrae following spaceflight

NASA Technical Reports Server (NTRS)

Eurell, J. A.; Kazarian, L. E.

1983-01-01

The histochemical effects of the return to gravity immediately and 6 and 29 days following spaceflight on the bone of rat vertebral bodies were investigated. No significant change in the calcium salt content of the vertebrae was found immediately postflight, although 6 days later it was significantly decreased. The calcium content was found to have returned to normal by 29 days postflight. While postflight collagen content was not significantly altered, keratosulfate was found to be significantly higher in trabecular bone of rats immediately postflight and 6 days postflight. In addition, chondroitin sulfate was found to be increased in vertebral bone on days 6 and 29 postflight. These findings indicate that bone turnover slows in vertebrae during spaceflight allowing bone aging, which support the contention that a form of osteolysis begins immediately upon return to gravity to remove components of old bone at which time mineral levels decrease and levels of chondroitin and keratkosulfates shift. It was found that the osteolysis phase was quickly followed by new bone replacement which was completed before 29 days postspaceflight.

Arabidopsis gene expression patterns during spaceflight

NASA Astrophysics Data System (ADS)

Paul, A.-L.; Ferl, R. J.

The exposure of Arabidopsis thaliana (Arabidopsis) plants to spaceflight environments resulted in the differential expression of hundreds of genes. A 5 day mission on orbiter Columbia in 1999 (STS-93) carried transgenic Arabidopsis plants engineered with a transgene composed of the alcohol dehydrogenase (Adh) gene promoter linked to the β -Glucuronidase (GUS) reporter gene. The plants were used to evaluate the effects of spaceflight on two fronts. First, expression patterns visualized with the Adh/GUS transgene were used to address specifically the possibility that spaceflight induces a hypoxic stress response, and to assess whether any spaceflight response was similar to control terrestrial hypoxia-induced gene expression patterns. (Paul et al., Plant Physiol. 2001, 126:613). Second, genome-wide patterns of native gene expression were evaluated utilizing the Affymetrix ATH1 GeneChip? array of 8,000 Arabidopsis genes. As a control for the veracity of the array analyses, a selection of genes identified with the arrays was further characterized with quantitative Real-Time RT PCR (ABI - TaqmanTM). Comparison of the patterns of expression for arrays of hybridized with RNA isolated from plants exposed to spaceflight compared to the control arrays revealed hundreds of genes that were differentially expressed in response to spaceflight, yet most genes that are hallmarks of hypoxic stress were unaffected. These results will be discussed in light of current models for plant responses to the spaceflight environment, and with regard to potential future flight opportunities.

Altered Functionality of Anti-Bacterial Antibodies in Patients with Chronic Hepatitis C Virus Infection

PubMed Central

Lamontagne, Anne; Long, Ronald E.; Comunale, Mary Ann; Hafner, Julie; Rodemich-Betesh, Lucy; Wang, Mengjun; Marrero, Jorge; Di Bisceglie, Adrian M.; Block, Timothy; Mehta, Anand

2013-01-01

Background Using comparative glycoproteomics, we have previously identified a glycoprotein that is altered in both amount and glycosylation as a function of liver cirrhosis. The altered glycoprotein is an agalactosylated (G0) immunoglobulin G molecule (IgG) that recognizes the heterophilic alpha-gal epitope. Since the alpha gal epitope is found on gut enterobacteria, it has been hypothesized that anti-gal antibodies are generated as a result of increased bacterial exposure in patients with liver disease. Methods The N-linked glycosylation of anti-gal IgG molecules from patients with fibrosis and cirrhosis was determined and the effector function of anti-bacterial antibodies from over 100 patients examined. In addition, markers of microbial exposure were determined. Results Surprisingly, the subset of agalactosylated anti-gal antibodies described here, was impaired in their ability to mediate complement mediated lysis and inhibited the complement-mediated destruction of common gut bacteria. In an analysis of serum from more than 100 patients with liver disease, we have shown that those with increased levels of this modified anti-gal antibody had increased levels of markers of bacterial exposure. Conclusions Anti-gal antibodies in patients with liver cirrhosis were reduced in their ability to mediate complement mediated lysis of target cells. As bacterial infection is a major complication in patients with cirrhosis and bacterial products such as LPS are thought to play a major role in the development and progression of liver fibrosis, this finding has many clinical implications in the etiology, prognosis and treatment of liver disease. PMID:23750224

Antibody responses to bacteriophage phi X-174 in human subjects exposed to the antarctic winter-over model of spaceflight

NASA Technical Reports Server (NTRS)

Shearer, W. T.; Lugg, D. J.; Rosenblatt, H. M.; Nickolls, P. M.; Sharp, R. M.; Reuben, J. M.; Ochs, H. D.

2001-01-01

BACKGROUND: It has been proposed that exposure to long-term spaceflight conditions (stress, isolation, sleep disruption, containment, microbial contamination, and solar radiation) or to ground-based models of spaceflight will alter human immune responses, but specific antibody responses have not been fully evaluated. OBJECTIVE: We sought to determine whether exposure to the 8-month Antarctic winter-over model of spaceflight would alter human antibody responses. METHODS: During the 1999 Australian National Antarctic Research Expeditions, 11 adult study subjects at Casey, Antarctica, and 7 control subjects at Macquarie Island, sub-Antarctica, received primary and secondary immunizations with the T cell-dependent neoantigen bacteriophage phi X-174. Periodic plasma samples were analyzed for specific antibody function. RESULTS: All of the subjects from Casey, Antarctica, cleared bacteriophage phi X-174 normally by 1 week after primary immunization, and all had normal primary and secondary antibody responses, including immunologic memory amplification and switch from IgM to IgG antibody production. One subject showed a high normal pattern, and one subject had a low normal pattern. The control subjects from Macquarie Island also had normal immune responses to bacteriophage phi X-174. CONCLUSIONS: These data do not support the hypothesis that de novo specific antibody responses of subjects become defective during the conditions of the Antarctic winter-over. Because the Antarctic winter-over model of spaceflight lacks the important factors of microgravity and solar radiation, caution must be used in interpreting these data to anticipate normal antibody responses in long-term spaceflight.

Increased postflight carotid artery stiffness and inflight insulin resistance resulting from 6-mo spaceflight in male and female astronauts.

PubMed

Hughson, Richard L; Robertson, Andrew D; Arbeille, Philippe; Shoemaker, J Kevin; Rush, James W E; Fraser, Katelyn S; Greaves, Danielle K

2016-03-01

Removal of the normal head-to-foot gravity vector and chronic weightlessness during spaceflight might induce cardiovascular and metabolic adaptations related to changes in arterial pressure and reduction in physical activity. We tested hypotheses that stiffness of arteries located above the heart would be increased postflight, and that blood biomarkers inflight would be consistent with changes in vascular function. Possible sex differences in responses were explored in four male and four female astronauts who lived on the International Space Station for 6 mo. Carotid artery distensibility coefficient (P = 0.005) and β-stiffness index (P = 0.006) reflected 17-30% increases in arterial stiffness when measured within 38 h of return to Earth compared with preflight. Spaceflight-by-sex interaction effects were found with greater changes in β-stiffness index in women (P = 0.017), but greater changes in pulse wave transit time in men (P = 0.006). Several blood biomarkers were changed from preflight to inflight, including an increase in an index of insulin resistance (P < 0.001) with a spaceflight-by-sex term suggesting greater change in men (P = 0.034). Spaceflight-by-sex interactions for renin (P = 0.016) and aldosterone (P = 0.010) indicated greater increases in women than men. Six-month spaceflight caused increased arterial stiffness. Altered hydrostatic arterial pressure gradients as well as changes in insulin resistance and other biomarkers might have contributed to alterations in arterial properties, including sex differences between male and female astronauts. Copyright © 2016 the American Physiological Society.

Alteration textures in terrestrial volcanic glass and the associated bacterial community.

PubMed

Cockell, C S; Olsson-Francis, K; Herrera, A; Meunier, A

2009-01-01

Alteration textures were examined in subglacial (hyaloclastite) deposits at Valafell, Southern Iceland. Pitted and 'elongate' alteration features are observed in the glass similar to granular and tubular features reported previously in deep-ocean basaltic glasses, but elongate features generally did not have a length to width ratio greater than five. Elongate features were found in only 7% of surfaces. Crystalline basalt clasts, which are incorporated into the hyaloclastite, did not display elongate structures. Pitted alteration features were poorly defined in crystalline basalt, comprising only 4% of the surface compared to 47% in the case of basaltic glass. Examination of silica-rich glass (obsidian) and rhyolite similarly showed poorly defined pitted textures that comprised less than 15% of the surface and no elongate features were observed. These data highlight the differences in alteration textures between terrestrial basaltic glass and previously studied deep-ocean and subsurface basaltic glass, and the important role of mineralogy in controlling the type and abundance of alteration features. The hyaloclastite contains a diverse and abundant bacterial population, as determined by 16S rDNA analysis, which could be involved in weathering the glass. Despite the presence of phototrophs, we show that they were not involved in the production of most alteration textures in the basaltic glass materials we examined.

Effects of 14 days of spaceflight and nine days of recovery on cell body size and succinate dehydrogenase activity of rat dorsal root ganglion neurons

NASA Technical Reports Server (NTRS)

Ishihara, A.; Ohira, Y.; Roy, R. R.; Nagaoka, S.; Sekiguchi, C.; Hinds, W. E.; Edgerton, V. R.

1997-01-01

The cross-sectional areas and succinate dehydrogenase activities of L5 dorsal root ganglion neurons in rats were determined after 14 days of spaceflight and after nine days of recovery. The mean and distribution of the cross-sectional areas were similar to age-matched, ground-based controls for both the spaceflight and for the spaceflight plus recovery groups. The mean succinate dehydrogenase activity was significantly lower in spaceflight compared to aged-matched control rats, whereas the mean succinate dehydrogenase activity was similar in age-matched control and spaceflight plus recovery rats. The mean succinate dehydrogenase activity of neurons with cross-sectional areas between 1000 and 2000 microns2 was lower (between 7 and 10%) in both the spaceflight and the spaceflight plus recovery groups compared to the appropriate control groups. The reduction in the oxidative capacity of a subpopulation of sensory neurons having relatively large cross-sectional areas immediately following spaceflight and the sustained depression for nine days after returning to 1 g suggest that the 0 g environment induced significant alterations in proprioceptive function.

Reduction in Dynamic Visual Acuity Reveals Gaze Control Changes Following Spaceflight

NASA Technical Reports Server (NTRS)

Peters, Brian T.; Brady, Rachel A.; Miller, Chris; Lawrence, Emily L.; Mulavara Ajitkumar P.; Bloomberg, Jacob J.

2010-01-01

INTRODUCTION: Exposure to microgravity causes adaptive changes in eye-head coordination that can lead to altered gaze control. This could affect postflight visual acuity during head and body motion. The goal of this study was to characterize changes in dynamic visual acuity after long-duration spaceflight. METHODS: Dynamic Visual Acuity (DVA) data from 14 astro/cosmonauts were collected after long-duration (6 months) spaceflight. The difference in acuity between seated and walking conditions provided a metric of change in the subjects ability to maintain gaze fixation during self-motion. In each condition, a psychophysical threshold detection algorithm was used to display Landolt ring optotypes at a size that was near each subject s acuity threshold. Verbal responses regarding the orientation of the gap were recorded as the optotypes appeared sequentially on a computer display 4 meters away. During the walking trials, subjects walked at 6.4 km/h on a motorized treadmill. RESULTS: A decrement in mean postflight DVA was found, with mean values returning to baseline within 1 week. The population mean showed a consistent improvement in DVA performance, but it was accompanied by high variability. A closer examination of the individual subject s recovery curves revealed that many did not follow a pattern of continuous improvement with each passing day. When adjusted on the basis of previous long-duration flight experience, the population mean shows a "bounce" in the re-adaptation curve. CONCLUSION: Gaze control during self-motion is altered following long-duration spaceflight and changes in postflight DVA performance indicate that vestibular re-adaptation may be more complex than a gradual return to normal.

David Lasser: An American Spaceflight Pioneer

NASA Astrophysics Data System (ADS)

Ciancone, Michael L.; Lasser, Amelia

2002-01-01

David Lasser was one of the founders of the American Interplanetary Society (later known as the American Rocket Society) and author of the first English-language book (in 1931) on the prospects of human spaceflight. Yet his involvement in the fledgling spaceflight movement was short-lived as he soon moved on to pursue a distinguished career in the cause of workers rights. In lieu of an oral history, the author corresponded with Mr. Lasser on a regular basis in the years before his death in 1996 to gather Mr. Lasser's views on human spaceflight activities as viewed from his unique perspective. This paper will document that correspondence with one of America's original spaceflight pioneers.

Long-Term Nitrogen Amendment Alters the Diversity and Assemblage of Soil Bacterial Communities in Tallgrass Prairie

PubMed Central

Todd, Timothy C.; Blair, John M.; Herman, Michael A.

2013-01-01

Anthropogenic changes are altering the environmental conditions and the biota of ecosystems worldwide. In many temperate grasslands, such as North American tallgrass prairie, these changes include alteration in historically important disturbance regimes (e.g., frequency of fires) and enhanced availability of potentially limiting nutrients, particularly nitrogen. Such anthropogenically-driven changes in the environment are known to elicit substantial changes in plant and consumer communities aboveground, but much less is known about their effects on soil microbial communities. Due to the high diversity of soil microbes and methodological challenges associated with assessing microbial community composition, relatively few studies have addressed specific taxonomic changes underlying microbial community-level responses to different fire regimes or nutrient amendments in tallgrass prairie. We used deep sequencing of the V3 region of the 16S rRNA gene to explore the effects of contrasting fire regimes and nutrient enrichment on soil bacterial communities in a long-term (20 yrs) experiment in native tallgrass prairie in the eastern Central Plains. We focused on responses to nutrient amendments coupled with two extreme fire regimes (annual prescribed spring burning and complete fire exclusion). The dominant bacterial phyla identified were Proteobacteria, Verrucomicrobia, Bacteriodetes, Acidobacteria, Firmicutes, and Actinobacteria and made up 80% of all taxa quantified. Chronic nitrogen enrichment significantly impacted bacterial community diversity and community structure varied according to nitrogen treatment, but not phosphorus enrichment or fire regime. We also found significant responses of individual bacterial groups including Nitrospira and Gammaproteobacteria to long-term nitrogen enrichment. Our results show that soil nitrogen enrichment can significantly alter bacterial community diversity, structure, and individual taxa abundance, which have important

Carbon nanomaterials alter plant physiology and soil bacterial community composition in a rice-soil-bacterial ecosystem.

PubMed

Hao, Yi; Ma, Chuanxin; Zhang, Zetian; Song, Youhong; Cao, Weidong; Guo, Jing; Zhou, Guopeng; Rui, Yukui; Liu, Liming; Xing, Baoshan

2018-01-01

The aim of this study was to compare the toxicity effects of carbon nanomaterials (CNMs), namely fullerene (C 60 ), reduced graphene oxide (rGO) and multi-walled carbon nanotubes (MWCNTs), on a mini-ecosystem of rice grown in a loamy potted soil. We measured plant physiological and biochemical parameters and examined bacterial community composition in the CNMs-treated plant-soil system. After 30 days of exposure, all the three CNMs negatively affected the shoot height and root length of rice, significantly decreased root cortical cells diameter and resulted in shrinkage and deformation of cells, regardless of exposure doses (50 or 500 mg/kg). Additionally, at the high exposure dose of CNM, the concentrations of four phytohormones, including auxin, indoleacetic acid, brassinosteroid and gibberellin acid 4 in rice roots significantly increased as compared to the control. At the high exposure dose of MWCNTs and C 60 , activities of the antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD) in roots increased significantly. High-throughput sequencing showed that three typical CNMs had little effect on shifting the predominant soil bacterial species, but the presence of CNMs significantly altered the composition of the bacterial community. Our results indicate that different CNMs indeed resulted in environmental toxicity to rice and soil bacterial community in the rhizosphere and suggest that CNMs themselves and their incorporated products should be reasonably used to control their release/discharge into the environment to prevent their toxic effects on living organisms and the potential risks to food safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of spaceflight and microgravity on the human brain.

PubMed

Van Ombergen, Angelique; Demertzi, Athena; Tomilovskaya, Elena; Jeurissen, Ben; Sijbers, Jan; Kozlovskaya, Inessa B; Parizel, Paul M; Van de Heyning, Paul H; Sunaert, Stefan; Laureys, Steven; Wuyts, Floris L

2017-10-01

Microgravity, confinement, isolation, and immobilization are just some of the features astronauts have to cope with during space missions. Consequently, long-duration space travel can have detrimental effects on human physiology. Although research has focused on the cardiovascular and musculoskeletal system in particular, the exact impact of spaceflight on the human central nervous system remains to be determined. Previous studies have reported psychological problems, cephalic fluid shifts, neurovestibular problems, and cognitive alterations, but there is paucity in the knowledge of the underlying neural substrates. Previous space analogue studies and preliminary spaceflight studies have shown an involvement of the cerebellum, cortical sensorimotor, and somatosensory areas and the vestibular pathways. Extending this knowledge is crucial, especially in view of long-duration interplanetary missions (e.g., Mars missions) and space tourism. In addition, the acquired insight could be relevant for vestibular patients, patients with neurodegenerative disorders, as well as the elderly population, coping with multisensory deficit syndromes, immobilization, and inactivity.

Rapid Electrochemical Detection and Identification of Microbiological and Chemical Contaminants for Manned Spaceflight Project

NASA Technical Reports Server (NTRS)

Pierson, Duane; Botkin, Douglas; Gazda, Daniel

2014-01-01

Microbial control in the spacecraft environment is a daunting task, especially in the presence of human crew members. Currently, assessing the potential crew health risk associated with a microbial contamination event requires return of representative environmental samples that are analyzed in a ground-based laboratory. It is therefore not currently possible to quickly identify microbes during spaceflight. This project addresses the unmet need for spaceflight-compatible microbial identification technology. The electrochemical detection and identification platform is expected to provide a sensitive, specific, and rapid sample-to-answer capability for in-flight microbial monitoring that can distinguish between related microorganisms (pathogens and non-pathogens) as well as chemical contaminants. This will dramatically enhance our ability to monitor the spacecraft environment and the health risk to the crew. Further, the project is expected to eliminate the need for sample return while significantly reducing crew time required for detection of multiple targets. Initial work will focus on the optimization of bacterial detection and identification. The platform is designed to release nucleic acids (DNA and RNA) from microorganisms without the use of harmful chemicals. Bacterial DNA or RNA is captured by bacteria-specific probe molecules that are bound to a microelectrode, and that capture event can generate a small change in the electrical current (Lam, et al. 2012. Anal. Chem. 84(1): 21-5.). This current is measured, and a determination is made whether a given microbe is present in the sample analyzed. Chemical detection can be accomplished by directly applying a sample to the microelectrode and measuring the resulting current change. This rapid microbial and chemical detection device is designed to be a low-cost, low-power platform anticipated to be operated independently of an external power source, characteristics optimal for manned spaceflight and areas where power

Spaceflight has compartment- and gene-specific effects on mRNA levels for bone matrix proteins in rat femur

NASA Technical Reports Server (NTRS)

Evans, G. L.; Morey-Holton, E.; Turner, R. T.

1998-01-01

In the present study, we evaluated the possibility that the abnormal bone matrix produced during spaceflight may be associated with reduced expression of bone matrix protein genes. To test this possibility, we investigated the effects of a 14-day spaceflight (SLS-2 experiment) on steady-state mRNA levels for glyceraldehyde-3-phosphate dehydrogenase (GAPDH), osteocalcin, osteonectin, and prepro-alpha(1) subunit of type I collagen in the major bone compartments of rat femur. There were pronounced site-specific differences in the steady-state levels of expression of the mRNAs for the three bone matrix proteins and GAPDH in normal weight-bearing rats, and these relationships were altered after spaceflight. Specifically, spaceflight resulted in decreases in mRNA levels for GAPDH (decreased in proximal metaphysis), osteocalcin (decreased in proximal metaphysis), osteonectin (decreased in proximal and distal metaphysis), and collagen (decreased in proximal and distal metaphysis) compared with ground controls. There were no changes in mRNA levels for matrix proteins or GAPDH in the shaft and distal epiphysis. These results demonstrate that spaceflight leads to site- and gene-specific decreases in mRNA levels for bone matrix proteins. These findings are consistent with the hypothesis that spaceflight-induced decreases in bone formation are caused by concomitant decreases in expression of genes for bone matrix proteins.

Cardiovascular instrumentation for spaceflight

NASA Technical Reports Server (NTRS)

Schappell, R. T.; Polhemus, J. T.; Ganiaris, N. J.

1976-01-01

The observation mechanisms dealing with pressure, flow, morphology, temperature, etc. are discussed. The approach taken in the performance of this study was to (1) review ground and space-flight data on cardiovascular function, including earlier related ground-based and space-flight animal studies, Mercury, Gemini, Apollo, Skylab, and recent bed-rest studies, (2) review cardiovascular measurement parameters required to assess individual performance and physiological alternations during space flight, (3) perform an instrumentation survey including a literature search as well as personal contact with the applicable investigators, (4) assess instrumentation applicability with respect to the established criteria, and (5) recommend future research and development activity. It is concluded that, for the most part, the required instrumentation technology is available but that mission-peculiar criteria will require modifications to adapt the applicable instrumentation to a space-flight configuration.

Women's health in spaceflight.

PubMed

Drudi, Laura; Grenon, S Marlene

2014-06-01

To review the current state of knowledge with regards to clinical challenges related to women's health during spaceflight. Articles were reviewed relevant to "women", "sex," and "gender" in "microgravity," "weightlessness," and "spaceflight" in the English and Russian languages. There were 50 papers identified. Studies have shown that crewmembers suffer from space motion sickness, but gender discrepancies have not been explored. Nearly all women experience orthostatic intolerance in space, which may be due to differences in female cardiovascular response. Immunosuppression in spaceflight results in susceptibility to opportunistic infections, but no studies have investigated gender differences. Finally, radiation exposure and germ cell viability influence the reproductive health of astronauts. With changes in space access offered by commercial space activities, research areas devoted to women's health in microgravity should become one of the priorities for safe space exploratory efforts.

Effects of One Year of Spaceflight on Neurocognitive Function

NASA Technical Reports Server (NTRS)

Seidler, R. D.; Mulavara, A. P.; Koppelmans, V.; Kofman, I. S.; Cassady, K.; Yuan , P.; De Dios, Y. E.; Gadd, N.; Riascos, R. F.; Wood, S. J.;

Sub-orbital commercial human spaceflight and informed consent.

PubMed

Carminati, Maria-Vittoria; Griffith, Doug; Campbell, Mark R

2011-02-01

Commercial spaceflight is expected to rapidly develop in the near future. This will begin with sub-orbital missions and then progress to orbital flights. Technical informed consent of spaceflight participants is required by the commercial spaceflight operator for regulatory purposes. Additionally, though not required by regulation, the aerospace medicine professional involved in the medical screening of both spaceflight participants and crewmembers will be asked to assist operators in obtaining medical informed consent for liability purposes. The various federal and state regulations regarding informed consent for sub-orbital commercial spaceflight are evolving and are unfamiliar to most aerospace medical professionals and are reviewed and discussed.

Development of a step-down method for altering male C57BL/6 mouse housing density and hierarchical structure: Preparations for spaceflight studies

NASA Astrophysics Data System (ADS)

Scofield, David C.; Rytlewski, Jeffrey D.; Childress, Paul; Shah, Kishan; Tucker, Aamir; Khan, Faisal; Peveler, Jessica; Li, Ding; McKinley, Todd O.; Chu, Tien-Min G.; Hickman, Debra L.; Kacena, Melissa A.

2018-05-01

This study was initiated as a component of a larger undertaking designed to study bone healing in microgravity aboard the International Space Station (ISS). Spaceflight experimentation introduces multiple challenges not seen in ground studies, especially with regard to physical space, limited resources, and inability to easily reproduce results. Together, these can lead to diminished statistical power and increased risk of failure. It is because of the limited space, and need for improved statistical power by increasing sample size over historical numbers, NASA studies involving mice require housing mice at densities higher than recommended in the Guide for the Care and Use of Laboratory Animals (National Research Council, 2011). All previous NASA missions in which mice were co-housed, involved female mice; however, in our spaceflight studies examining bone healing, male mice are required for optimal experimentation. Additionally, the logistics associated with spaceflight hardware and our study design necessitated variation of density and cohort make up during the experiment. This required the development of a new method to successfully co-house male mice while varying mouse density and hierarchical structure. For this experiment, male mice in an experimental housing schematic of variable density (Spaceflight Correlate) analogous to previously established NASA spaceflight studies was compared to a standard ground based housing schematic (Normal Density Controls) throughout the experimental timeline. We hypothesized that mice in the Spaceflight Correlate group would show no significant difference in activity, aggression, or stress when compared to Normal Density Controls. Activity and aggression were assessed using a novel activity scoring system (based on prior literature, validated in-house) and stress was assessed via body weights, organ weights, and veterinary assessment. No significant differences were detected between the Spaceflight Correlate group and the

Embryogenesis, hatching and larval development of Artemia during orbital spaceflight

NASA Astrophysics Data System (ADS)

Spooner, B. S.; Debell, L.; Armbrust, L.; Guikema, J. A.; Metcalf, J.; Paulsen, A.

1994-08-01

Developmental biology studies, using gastrula-arrested cysts of the brine shrimp Artemia franciscana, were conducted during two flights of the space shuttle Atlantis (missions STS-37 and STS-43) in 1991. Dehydrated cysts were activated, on orbit, by addition of salt water to the cysts, and then development was terminated by the addition of fixative. Development took place in 5 ml syringes, connected by tubing to activation syringes, containing salt water, and termination syringes, containing fixative. Comparison of space results with simultaneous ground control experiments showed that equivalent percentages of naupliar larvae hatched in the syringes (40%). Thus, reactivation of development, completion of embryogenesis, emergence and hatching took place, during spaceflight, without recognizable alteration in numbers of larvae produced. Post-hatching larval development was studied in experiments where development was terminated, by intrduction of fixative, 2 days, 4 days, and 8 days after reinitiation of development. During spaceflight, successive larval instars or stages, interrupted by molts, occurred, generating brine shrimp at appropriate larval instars. Naupliar larvae possessed the single naupliar eye, and development of the lateral pair of adult eyes also took place in space. Transmission electron microscopy revealed extensive differentiation, including skeletal muscle and gut endoderm, as well as the eye tissues. These studies demonstrate the potential value of Artemia for developmental biology studies during spaceflight, and show that extensive degress of development can take place in this microgravity environment.

Mutations That Alter the Bacterial Cell Envelope Increase Lipid Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemmer, Kimberly C.; Zhang, Weiping; Langer, Samantha J.

ABSTRACT Lipids from microbes offer a promising source of renewable alternatives to petroleum-derived compounds. In particular, oleaginous microbes are of interest because they accumulate a large fraction of their biomass as lipids. In this study, we analyzed genetic changes that alter lipid accumulation inRhodobacter sphaeroides. By screening anR. sphaeroidesTn5mutant library for insertions that increased fatty acid content, we identified 10 high-lipid (HL) mutants for further characterization. These HL mutants exhibited increased sensitivity to drugs that target the bacterial cell envelope and changes in shape, and some had the ability to secrete lipids, with two HL mutants accumulating ~60% of their totalmore » lipids extracellularly. When one of the highest-lipid-secreting strains was grown in a fed-batch bioreactor, its lipid content was comparable to that of oleaginous microbes, with the majority of the lipids secreted into the medium. Based on the properties of these HL mutants, we conclude that alterations of the cell envelope are a previously unreported approach to increase microbial lipid production. We also propose that this approach may be combined with knowledge about biosynthetic pathways, in this or other microbes, to increase production of lipids and other chemicals. IMPORTANCEThis paper reports on experiments to understand how to increase microbial lipid production. Microbial lipids are often cited as one renewable replacement for petroleum-based fuels and chemicals, but strategies to increase the yield of these compounds are needed to achieve this goal. While lipid biosynthesis is often well understood, increasing yields of these compounds to industrially relevant levels is a challenge, especially since genetic, synthetic biology, or engineering approaches are not feasible in many microbes. We show that altering the bacterial cell envelope can be used to increase microbial lipid production. We also find that the utility of some of these

Mutations That Alter the Bacterial Cell Envelope Increase Lipid Production.

PubMed

Lemmer, Kimberly C; Zhang, Weiping; Langer, Samantha J; Dohnalkova, Alice C; Hu, Dehong; Lemke, Rachelle A; Piotrowski, Jeff S; Orr, Galya; Noguera, Daniel R; Donohue, Timothy J

2017-05-23

Lipids from microbes offer a promising source of renewable alternatives to petroleum-derived compounds. In particular, oleaginous microbes are of interest because they accumulate a large fraction of their biomass as lipids. In this study, we analyzed genetic changes that alter lipid accumulation in Rhodobacter sphaeroides By screening an R. sphaeroides Tn 5 mutant library for insertions that increased fatty acid content, we identified 10 high-lipid (HL) mutants for further characterization. These HL mutants exhibited increased sensitivity to drugs that target the bacterial cell envelope and changes in shape, and some had the ability to secrete lipids, with two HL mutants accumulating ~60% of their total lipids extracellularly. When one of the highest-lipid-secreting strains was grown in a fed-batch bioreactor, its lipid content was comparable to that of oleaginous microbes, with the majority of the lipids secreted into the medium. Based on the properties of these HL mutants, we conclude that alterations of the cell envelope are a previously unreported approach to increase microbial lipid production. We also propose that this approach may be combined with knowledge about biosynthetic pathways, in this or other microbes, to increase production of lipids and other chemicals. IMPORTANCE This paper reports on experiments to understand how to increase microbial lipid production. Microbial lipids are often cited as one renewable replacement for petroleum-based fuels and chemicals, but strategies to increase the yield of these compounds are needed to achieve this goal. While lipid biosynthesis is often well understood, increasing yields of these compounds to industrially relevant levels is a challenge, especially since genetic, synthetic biology, or engineering approaches are not feasible in many microbes. We show that altering the bacterial cell envelope can be used to increase microbial lipid production. We also find that the utility of some of these alterations can be

Mutations That Alter the Bacterial Cell Envelope Increase Lipid Production

DOE PAGES

Lemmer, Kimberly C.; Zhang, Weiping; Langer, Samantha J.; ...

2017-05-23

ABSTRACT Lipids from microbes offer a promising source of renewable alternatives to petroleum-derived compounds. In particular, oleaginous microbes are of interest because they accumulate a large fraction of their biomass as lipids. In this study, we analyzed genetic changes that alter lipid accumulation inRhodobacter sphaeroides. By screening anR. sphaeroidesTn5mutant library for insertions that increased fatty acid content, we identified 10 high-lipid (HL) mutants for further characterization. These HL mutants exhibited increased sensitivity to drugs that target the bacterial cell envelope and changes in shape, and some had the ability to secrete lipids, with two HL mutants accumulating ~60% of their totalmore » lipids extracellularly. When one of the highest-lipid-secreting strains was grown in a fed-batch bioreactor, its lipid content was comparable to that of oleaginous microbes, with the majority of the lipids secreted into the medium. Based on the properties of these HL mutants, we conclude that alterations of the cell envelope are a previously unreported approach to increase microbial lipid production. We also propose that this approach may be combined with knowledge about biosynthetic pathways, in this or other microbes, to increase production of lipids and other chemicals. IMPORTANCEThis paper reports on experiments to understand how to increase microbial lipid production. Microbial lipids are often cited as one renewable replacement for petroleum-based fuels and chemicals, but strategies to increase the yield of these compounds are needed to achieve this goal. While lipid biosynthesis is often well understood, increasing yields of these compounds to industrially relevant levels is a challenge, especially since genetic, synthetic biology, or engineering approaches are not feasible in many microbes. We show that altering the bacterial cell envelope can be used to increase microbial lipid production. We also find that the utility of some of these

Cardiovascular adaptation to spaceflight

NASA Technical Reports Server (NTRS)

Hargens, A. R.; Watenpaugh, D. E.

1996-01-01

This article reviews recent flight and ground-based studies of cardiovascular adaptation to spaceflight. Prominent features of microgravity exposure include loss of gravitational pressures, relatively low venous pressures, headward fluid shifts, plasma volume loss, and postflight orthostatic intolerance and reduced exercise capacity. Many of these short-term responses to microgravity extend themselves during long-duration microgravity exposure and may be explained by altered pressures (blood and tissue) and fluid balance in local tissues nourished by the cardiovascular system. In this regard, it is particularly noteworthy that tissues of the lower body (e.g., foot) are well adapted to local hypertension on Earth, whereas tissues of the upper body (e.g., head) are not as well adapted to increase in local blood pressure. For these and other reasons, countermeasures for long-duration flight should include reestablishment of higher, Earth-like blood pressures in the lower body.

Spaceflight-induced neuroplasticity in humans as measured by MRI: what do we know so far?

PubMed

Van Ombergen, Angelique; Laureys, Steven; Sunaert, Stefan; Tomilovskaya, Elena; Parizel, Paul M; Wuyts, Floris L

2017-01-01

Space travel poses an enormous challenge on the human body; microgravity, ionizing radiation, absence of circadian rhythm, confinement and isolation are just some of the features associated with it. Obviously, all of the latter can have an impact on human physiology and even induce detrimental changes. Some organ systems have been studied thoroughly under space conditions, however, not much is known on the functional and morphological effects of spaceflight on the human central nervous system. Previous studies have already shown that central nervous system changes occur during and after spaceflight in the form of neurovestibular problems, alterations in cognitive function and sensory perception, cephalic fluid shifts and psychological disturbances. However, little is known about the underlying neural substrates. In this review, we discuss the current limited knowledge on neuroplastic changes in the human central nervous system associated with spaceflight (actual or simulated) as measured by magnetic resonance imaging-based techniques. Furthermore, we discuss these findings as well as their future perspectives, since this can encourage future research into this delicate and intriguing aspect of spaceflight. Currently, the literature suffers from heterogeneous experimental set-ups and therefore, the lack of comparability of findings among studies. However, the cerebellum, cortical sensorimotor and somatosensory areas and vestibular-related pathways seem to be involved across different studies, suggesting that these brain regions are most affected by (simulated) spaceflight. Extending this knowledge is crucial, especially with the eye on long-duration interplanetary missions (e.g. Mars) and space tourism.

Multicultural factors for international spaceflight.

PubMed

Kring, J P

2001-06-01

Spaceflight operations, including the International Space Station (ISS) and a mission to Mars, depend on international cooperation. Accordingly, safety, performance, and mission success rely on how well crews and operational personnel with different cultural backgrounds operate together. This paper outlines 10 areas related to spaceflight that are influenced by the national culture and backgrounds of personnel: (a) Communication, (b) Cognition and Decision Making, (c) Technology Interfacing, (d) Interpersonal Interactions, (e) Work, Management, and Leadership Style, (f) Personal Hygiene and Clothing, (g) Food Preparation and Meals, (h) Religion and Holidays, (i) Recreation, and (j) Habitat Aesthetics. Research findings and recommendations are presented, as well as a multicultural training approach to reduce potential challenges for long-duration spaceflight.

Human gut bacterial communities are altered by addition of cruciferous vegetables to a controlled fruit- and vegetable-free diet.

PubMed

Li, Fei; Hullar, Meredith A J; Schwarz, Yvonne; Lampe, Johanna W

2009-09-01

In the human gut, commensal bacteria metabolize food components that typically serve as energy sources. These components have the potential to influence gut bacterial community composition. Cruciferous vegetables, such as broccoli and cabbage, contain distinctive compounds that can be utilized by gut bacteria. For example, glucosinolates can be hydrolyzed by certain bacteria, and dietary fibers can be fermented by a range of species. We hypothesized that cruciferous vegetable consumption would alter growth of certain bacteria, thereby altering bacterial community composition. We tested this hypothesis in a randomized, crossover, controlled feeding study. Fecal samples were collected from 17 participants at the end of 2 14-d intake periods: a low-phytochemical, low-fiber basal diet (i.e. refined grains without fruits or vegetables) and a high ("double") cruciferous vegetable diet [basal diet + 14 g cruciferous vegetables/(kg body weightd)]. Fecal bacterial composition was analyzed by the terminal restriction fragment length polymorphism (tRFLP) method using the bacterial 16S ribosomal RNA gene and nucleotide sequencing. Using blocked multi-response permutation procedures analysis, we found that overall bacterial community composition differed between the 2 consumption periods (delta = 0.603; P = 0.011). The bacterial community response to cruciferous vegetables was individual-specific, as revealed by nonmetric multidimensional scaling ordination analysis. Specific tRFLP fragments that characterized each of the diets were identified using indicator species analysis. Putative species corresponding to these fragments were identified through gene sequencing as Eubacterium hallii, Phascolarctobacterium faecium, Burkholderiales spp., Alistipes putredinis, and Eggerthella spp. In conclusion, human gut bacterial community composition was altered by cruciferous vegetable consumption, which could ultimately influence gut metabolism of bioactive food components and host

One-month spaceflight compromises the bone microstructure, tissue-level mechanical properties, osteocyte survival and lacunae volume in mature mice skeletons.

PubMed

Gerbaix, Maude; Gnyubkin, Vasily; Farlay, Delphine; Olivier, Cécile; Ammann, Patrick; Courbon, Guillaume; Laroche, Norbert; Genthial, Rachel; Follet, Hélène; Peyrin, Françoise; Shenkman, Boris; Gauquelin-Koch, Guillemette; Vico, Laurence

2017-06-01

The weightless environment during spaceflight induces site-specific bone loss. The 30-day Bion-M1 mission offered a unique opportunity to characterize the skeletal changes after spaceflight and an 8-day recovery period in mature male C57/BL6 mice. In the femur metaphysis, spaceflight decreased the trabecular bone volume (-64% vs. Habitat Control), dramatically increased the bone resorption (+140% vs. Habitat Control) and induced marrow adiposity invasion. At the diaphysis, cortical thinning associated with periosteal resorption was observed. In the Flight animal group, the osteocyte lacunae displayed a reduced volume and a more spherical shape (synchrotron radiation analyses), and empty lacunae were highly increased (+344% vs. Habitat Control). Tissue-level mechanical cortical properties (i.e., hardness and modulus) were locally decreased by spaceflight, whereas the mineral characteristics and collagen maturity were unaffected. In the vertebrae, spaceflight decreased the overall bone volume and altered the modulus in the periphery of the trabecular struts. Despite normalized osteoclastic activity and an increased osteoblast number, bone recovery was not observed 8 days after landing. In conclusion, spaceflight induces osteocyte death, which may trigger bone resorption and result in bone mass and microstructural deterioration. Moreover, osteocyte cell death, lacunae mineralization and fatty marrow, which are hallmarks of ageing, may impede tissue maintenance and repair.

Spaceflight and simulated microgravity cause a significant reduction of key gene expression in early T-cell activation

PubMed Central

Martinez, Emily M.; Yoshida, Miya C.; Candelario, Tara Lynne T.

2015-01-01

Healthy immune function depends on precise regulation of lymphocyte activation. During the National Aeronautics and Space Administration (NASA) Apollo and Shuttle eras, multiple spaceflight studies showed depressed lymphocyte activity under microgravity (μg) conditions. Scientists on the ground use two models of simulated μg (sμg): 1) the rotating wall vessel (RWV) and 2) the random positioning machine (RPM), to study the effects of altered gravity on cell function before advancing research to the true μg when spaceflight opportunities become available on the International Space Station (ISS). The objective of this study is to compare the effects of true μg and sμg on the expression of key early T-cell activation genes in mouse splenocytes from spaceflight and ground animals. For the first time, we compared all three conditions of microgravity spaceflight, RPM, and RWV during immune gene activation of Il2, Il2rα, Ifnγ, and Tagap; moreover, we confirm two new early T-cell activation genes, Iigp1 and Slamf1. Gene expression for all samples was analyzed using quantitative real-time PCR (qRT-PCR). Our results demonstrate significantly increased gene expression in activated ground samples with suppression of mouse immune function in spaceflight, RPM, and RWV samples. These findings indicate that sμg models provide an excellent test bed for scientists to develop baseline studies and augment true μg in spaceflight experiments. Ultimately, sμg and spaceflight studies in lymphocytes may provide insight into novel regulatory pathways, benefiting both future astronauts and those here on earth suffering from immune disorders. PMID:25568077

Spaceflight and simulated microgravity cause a significant reduction of key gene expression in early T-cell activation.

PubMed

Martinez, Emily M; Yoshida, Miya C; Candelario, Tara Lynne T; Hughes-Fulford, Millie

2015-03-15

Healthy immune function depends on precise regulation of lymphocyte activation. During the National Aeronautics and Space Administration (NASA) Apollo and Shuttle eras, multiple spaceflight studies showed depressed lymphocyte activity under microgravity (μg) conditions. Scientists on the ground use two models of simulated μg (sμg): 1) the rotating wall vessel (RWV) and 2) the random positioning machine (RPM), to study the effects of altered gravity on cell function before advancing research to the true μg when spaceflight opportunities become available on the International Space Station (ISS). The objective of this study is to compare the effects of true μg and sμg on the expression of key early T-cell activation genes in mouse splenocytes from spaceflight and ground animals. For the first time, we compared all three conditions of microgravity spaceflight, RPM, and RWV during immune gene activation of Il2, Il2rα, Ifnγ, and Tagap; moreover, we confirm two new early T-cell activation genes, Iigp1 and Slamf1. Gene expression for all samples was analyzed using quantitative real-time PCR (qRT-PCR). Our results demonstrate significantly increased gene expression in activated ground samples with suppression of mouse immune function in spaceflight, RPM, and RWV samples. These findings indicate that sμg models provide an excellent test bed for scientists to develop baseline studies and augment true μg in spaceflight experiments. Ultimately, sμg and spaceflight studies in lymphocytes may provide insight into novel regulatory pathways, benefiting both future astronauts and those here on earth suffering from immune disorders.

Immune System Dysregulation, Viral Reactivation and Stress During Short-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Pierson, Duane; Sams, Clarence; Crucian, Brian; Mehta, Satish; Stowe, Raymond; Uchakin, Peter; Quiriarte, Heather

2010-01-01

The objective of this NASA Short-Duration Bioastronautics Investigation (SDBI) was to assess spaceflight-associated immune dysregulation. Many previous studies have investigated this phenomenon post-flight, and found altered distribution and function of the peripheral leukocyte populations. Alterations in cytokine production profiles have also been reported. Unfortunately, post-flight data may be altered by the stress associated with high-G re-entry and readaptation to unit gravity following deconditioning. Therefore, the current study collected blood and saliva samples from crewmembers immediately before landing, and returned those samples to Earth for terrestrial analysis. Assays include peripheral comprehensive immunophenotype, T cell function, cytokine profiles, viral-specific immunity, latent viral reactivation (EBV, CMV, VZV), and stress hormone measurements. A total of 18 short duration crewmembers completed the study and the final data will be presented.

The postmitotic Saccharomyces cerevisiae after spaceflight showed higher viability

NASA Astrophysics Data System (ADS)

Yi, Zong-Chun; Li, Xiao-Fei; Wang, Yan; Wang, Jie; Sun, Yan; Zhuang, Feng-Yuan

2011-06-01

The budding yeast Saccharomyces cerevisiae has been proposed as an ideal model organism for clarifying the biological effects caused by spaceflight conditions. The postmitotic S. cerevisiae cells onboard Practice eight recoverable satellite were subjected to spaceflight for 15 days. After recovery, the viability, the glycogen content, the activities of carbohydrate metabolism enzymes, the DNA content and the lipid peroxidation level in yeast cells were analyzed. The viability of the postmitotic yeast cells after spaceflight showed a three-fold increase as compared with that of the ground control cells. Compared to the ground control cells, the lipid peroxidation level in the spaceflight yeast cells markedly decreased. The spaceflight yeast cells also showed an increase in G2/M cell population and a decrease in Sub-G1 cell population. The glycogen content and the activities of hexokinase and succinate dehydrogenase significantly decreased in the yeast cells after spaceflight. In contrast, the activity of malate dehydrogenase showed an obvious increase after spaceflight. These results suggested that microgravity or spaceflight could promote the survival of postmitotic S. cerevisiae cells through regulating carbohydrate metabolism, ROS level and cell cycle progression.

Nutritional Concerns of Spaceflight

NASA Technical Reports Server (NTRS)

Smith, Scott M.; Rice, Barbara L.

2002-01-01

Nutrition has played a critical role throughout the history of exploration, and space exploration is no exception. While a one- to two-week flight aboard the Space Shuttle might be analogous to a camping trip, adequate nutrition is absolutely critical while spending several months on the International Space Station (Figure 1) or several years on a mission to another planet. To ensure adequate nutrition, space nutrition specialists must know how much of the individual nutrients astronauts need, and these nutrients must be available in the spaceflight food system. To complicate matters, these spaceflight nutritional requirements are influenced by many of the physiological changes that occur during spaceflight. In this chapter, we describe some of these changes, their impact on crew health, and ways NASA is investigating how to minimize these changes. We also review the space food systems, issues involved in setting up a cafeteria in a weightless environment, and information about dietary intake of nutrients during space missions

Development of a step-down method for altering male C57BL/6 mouse housing density and hierarchical structure: Preparations for spaceflight studies.

PubMed

Scofield, David C; Rytlewski, Jeffrey D; Childress, Paul; Shah, Kishan; Tucker, Aamir; Khan, Faisal; Peveler, Jessica; Li, Ding; McKinley, Todd O; Chu, Tien-Min G; Hickman, Debra L; Kacena, Melissa A

2018-05-01

This study was initiated as a component of a larger undertaking designed to study bone healing in microgravity aboard the International Space Station (ISS). Spaceflight experimentation introduces multiple challenges not seen in ground studies, especially with regard to physical space, limited resources, and inability to easily reproduce results. Together, these can lead to diminished statistical power and increased risk of failure. It is because of the limited space, and need for improved statistical power by increasing sample size over historical numbers, NASA studies involving mice require housing mice at densities higher than recommended in the Guide for the Care and Use of Laboratory Animals (National Research Council, 2011). All previous NASA missions in which mice were co-housed, involved female mice; however, in our spaceflight studies examining bone healing, male mice are required for optimal experimentation. Additionally, the logistics associated with spaceflight hardware and our study design necessitated variation of density and cohort make up during the experiment. This required the development of a new method to successfully co-house male mice while varying mouse density and hierarchical structure. For this experiment, male mice in an experimental housing schematic of variable density (Spaceflight Correlate) analogous to previously established NASA spaceflight studies was compared to a standard ground based housing schematic (Normal Density Controls) throughout the experimental timeline. We hypothesized that mice in the Spaceflight Correlate group would show no significant difference in activity, aggression, or stress when compared to Normal Density Controls. Activity and aggression were assessed using a novel activity scoring system (based on prior literature, validated in-house) and stress was assessed via body weights, organ weights, and veterinary assessment. No significant differences were detected between the Spaceflight Correlate group and the

Bone Loss During Spaceflight: Available Models and Counter-Measures

NASA Technical Reports Server (NTRS)

Morris, Jonathan; Bach, David; Geller, David

2015-01-01

There is ongoing concern for human health during spaceflights. Of particular interest is the uncoupling of bone remodeling and its resultant effect on calcium metabolism and bone loss. The calculated average loss of bone mineral density (BMD) is approximately 1-1.5% per month of spaceflight. The effect of decreased BMD on associated fractures in astronauts is not known. Currently on the International Space Station (ISS), bone loss is managed through dietary supplements and modifications and resistance exercise regimen. As the duration of space flights increases, a review of the current methods available for the prevention of bone loss is warranted. The goal of this project is to review and summarize recent studies that have focused on maintaining BMD during exposure to microgravity. Interventions were divided into physical (Table 1), nutritional (Table 2), or pharmacologic (Table 3) categories. Physical modalities included resistance exercise, low level vibration, and low intensity pulsed ultrasound. Nutritional interventions included altering protein, salt, and fat intake; and vitamin D supplementation. Pharmacologic interventions included the use of bisphosphonates and beta blockers. Studies reported outcomes based on bone density determined by DXA bone scan, micro-architecture of histology and microCT, and serum and urine markers of bone turnover. The ground analog models utilized to approximate osseous physiology in microgravity included human patients previously paralyzed or subjects confined to bedrest. Ground analog animal models include paralysis, immobilization and ovariectomies. As a result of the extensive research performed there is a multi-modality approach available for the management of BMD during spaceflight that includes resistance training, nutrition and dietary supplements. However, there is a paucity of literature describing a formalized tiered protocol to guide investigators through the progression from animal models to human patient ground

Regulation of Blood Volume During Spaceflight

NASA Technical Reports Server (NTRS)

Alfrey, Clarence P.

1997-01-01

The effects of spaceflight on erythropoiesis and blood volume in the rat were studied during the 14-day NASA Spacelab Life Sciences 2 (SLS-2) Shuttle mission. Measurements included red blood cell mass (RBCM), plasma volume (PV), iron utilization and iron utilization in response to an injection of erythropoietin. Red blood cell (RBC) survival, splenic sequestration and erythrocyte morphology were also evaluated. At landing, the RBCM adjusted for body weight was significantly lower in the flight animals than in the ground controls. While the PV was also decreased, the change was not statistically significant. Incorporation of iron into circulating RBCs was normal when measured after five days of spaceflight and the rat responded normally to the single in-flight injection of erythropoietin. No change in RBC morphology could be attributed to spaceflight. A normal survival was found for the RBC population that was represented by Cr-51 labeled RBCS. These results demonstrate that rats, like humans, return from spaceflight with a decreased RBCM and total blood volume.

Raman spectroscopy of murine bone in response to simulated spaceflight conditions

NASA Astrophysics Data System (ADS)

Mandair, Gurjit S.; Bateman, Ted A.; Morris, Michael D.

2009-02-01

Astronauts exposed to spaceflight conditions can lose 1-2% of their bone mineral density per month from the weight-bearing portions of the skeletal system. Low bone mineral density, termed osteopenia, is the result of decreased bone formation and/or increased bone resorption. In this study, Raman spectroscopy is used to examine if the physicochemical composition of murine femurs is altered in response to simulated spaceflight conditions (hindlimb suspension). Female C57BL/6J mice, aged 53 days, were divided into ground control and simulated spaceflight groups for a period of 12 days, modeling the experiment profile of mice flown on Space Shuttle flight STS-108. After the study, the mice were sacrificed and femur specimens harvested. Mid-diaphysis sections were probed using near-infrared Raman microscopy. Spectra were collected at various anatomical sites (anterior, lateral, medial, and posterior quadrants) and/or cortical locations (periosteal, midosteal, and endosteal). Chemometric recovery of spectra was employed to reduce signal contributions from the epoxy embedding agent. Mean values for mineralization, carbonation, crystallinity, and other parameters associated with the matrix were estimated. Correlations between mineralization and carbonation were observed, despite the small absolute changes between the two groups. We present more detailed analysis of this data and comment on the prospects for Raman spectroscopic evaluation of bone quality in hindlimb suspended (HLS) specimens.

Bioturbating shrimp alter the structure and diversity of bacterial communities in coastal marine sediments.

PubMed

Laverock, Bonnie; Smith, Cindy J; Tait, Karen; Osborn, A Mark; Widdicombe, Steve; Gilbert, Jack A

2010-12-01

bacterial diversity in surface sediments and resulting in distinct bacterial communities even at depth within the burrow. In an area of high macrofaunal abundance, this could lead to alterations in the microbial transformations of important nutrients at the sediment-water interface.

Suborbital commercial spaceflight crewmember medical issues.

PubMed

2011-04-01

As directed by the Council of the Aerospace Medical Association, the Commercial Spaceflight Working Group has developed the following position paper concerning medical issues for commercial suborbital spaceflight crewmembers. This position paper has been approved by the AsMA Council to become a policy of the AsMA.

Skeletal responses to spaceflight

NASA Technical Reports Server (NTRS)

Morey-Holton, Emily R.; Arnaud, Sara B.

1991-01-01

The effect of gravity on the skeletal development and on the bone composition and its regulation in vertebrates is discussed. Results are presented from spaceflight and ground studies in both man and rat on the effect of microgravity on the bone-mineral metabolism (in both species) and on bone maturation and growth (in rats). Special attention is given to a ground-based flight-simulation rat model developed at NASA's Ames Research Center for studies of bone structure at the molecular, organ, and whole-body levels and to comparisons of estimated results with spaceflight data.

Plasma Cytokine Levels During Long-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Crucian, Brian E.; Zwart, Sara R.; Quiriarte, Heather A.; Smith, Scott M.; Sams, Clarence F.

2011-01-01

Reduced T cell, granulocyte, NK and monocyte function have all been reported following both long and short duration spaceflight, however these data indicate crews are generally not experiencing inflammatory or adaptive immune activation during spaceflight. There appear to be varied individual crew responses, and specific relationships between cytokines and markers of iron status and muscle turnover that warrant further evaluation. Increases in growth factors and chemokines may indicate other types of adaptation occurring during spaceflight, such as attempts to overcome diminished immunocyte function.

Spaceflight-induced genetic and epigenetic changes in the rice (Oryza sativa L.) genome are independent of each other.

PubMed

Ou, Xiufang; Long, Likun; Wu, Ying; Yu, Yingjie; Lin, Xiuyun; Qi, Xin; Liu, Bao

2010-07-01

An array of studies have reported that the spaceflight environment is mutagenic and may induce phenotypic and genetic changes in diverse organisms. We reported recently that in at least some plant species (e.g., rice) the spaceflight environment can be particularly potent in generating heritable epigenetic changes in the form of altered cytosine methylation patterns and activation of transposable elements. To further study the issue of spaceflight-induced genomic instability, and in particular to test whether the incurred genetic and epigenetic changes are connected or independent of each other, we performed the present study. We subjected seeds of the standard laboratory rice (Oryza sativa L.) cultivar Nipponbare to a spaceflight in the spaceship Long March 2 for 18 days. We then investigated the genetic and DNA methylation stabilities of 11 randomly selected plants germinated from the spaceflown seeds by using two kinds of DNA markers, amplified fragment length polymorphism (AFLP) and methylation sensitive amplified polymorphism (MSAP). For AFLP, by using 15 primer combinations, we assessed 460 genomic loci and found that the frequencies of genetic changes across the 11 plants ranged from 0.7% to 6.7% with an average frequency of 3.5%. For MSAP, by using 14 primer combinations, we assessed 467 loci and detected the occurrence of four major types of cytosine methylation alterations at the CCGG sites, namely CG or CNG hypomethylation and CG or CNG hypermethylation. Collectively, the frequencies of the two kinds of hypermethylation, CG (1.95%) and CNG (1.44%), are about two times higher than those of the two kinds of hypomethylation, CG (0.76%) and CNG (0.80%), though different plants showed variable frequencies for each type of alteration. Further analysis suggested that both the genetic and cytosine methylation changes manifested apparent mutational bias towards specific genomic regions, but the two kinds of instabilities are independent of each other based on

Looking Backward, Looking Forward: Forty Years of US Human Spaceflight Symposium

NASA Technical Reports Server (NTRS)

Garber, Stephen J. (Editor); Launius, Roger (Technical Monitor)

2001-01-01

This symposium reflects on forty years of U.S. Human Spaceflight, its role over the next four decades and beyond. The topics include: 1) Perspectives on the Past Forty Years of Human Spaceflight; 2) The Experience of Spaceflight; 3) Perspectives on the Next Forty Years of Human Spaceflight; and 4) The International Space Station and the Future of Human Spaceflight.

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto is one of the scientists recovering experiments found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-06

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto is one of the scientists recovering experiments found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

Human skeletal muscle protein breakdown during spaceflight

NASA Technical Reports Server (NTRS)

Stein, T. P.; Schluter, M. D.

1997-01-01

Human spaceflight is associated with a loss of body protein. Excretion of 3-methylhistidine (3-MH) in the urine is a useful measurement of myofibrillar protein breakdown. Bed rest, particularly with 6 degrees head-down tilt, is an accepted ground-based model for human spaceflight. The objectives of this report were to compare 3-MH excretion from two Life Sciences shuttle missions (duration 9.5 and 15 days, n = 9) and from 17 days of bed rest (n = 7) with 6 degrees head-down tilt. The bed rest study was designed to mimic an actual Life Sciences spaceflight and so incorporated an extensive battery of physiological tests focused on the musculoskeletal system. Results showed that nitrogen retention, based on excretion of nitrogen in the urine, was reduced during both bed rest [from 22 +/- 1 to 1 +/- 5 mg N x kg(-1) x day(-1) (n = 7; P < 0.05)] and spaceflight [from 57 +/- 9 to 19 +/- 3 mg N x kg(-1) x day(-1) (n = 9; P < 0.05)]. 3-MH excretion was unchanged with either bed rest [pre-bed rest 5.30 +/- 0.29 vs. bed rest 5.71 +/- 0.30 micromol 3-MH x kg(-1) x day(-1), n = 7; P = not significant (NS)] or spaceflight [preflight 4.98 +/- 0.37 vs. 4.59 +/- 0.39 micromol 3-MH x kg(-1) x day(-1) in-flight, n = 9; P = NS]. We conclude that 1) 3-MH excretion was unaffected by spaceflight on the shuttle or with bed rest plus exercise, and 2) because protein breakdown (elevated 3-MH) was increased on Skylab but not on the shuttle, it follows that muscle protein breakdown is not an inevitable consequence of spaceflight.

Regional muscle loss after short duration spaceflight.

PubMed

LeBlanc, A; Rowe, R; Schneider, V; Evans, H; Hedrick, T

1995-12-01

Muscle strength and limb girth measurements during Skylab and Apollo missions suggested that loss of muscle mass may occur as a result of spaceflight. Extended duration spaceflight is important for the economical and practical use of space. The loss of muscle mass during spaceflight is a medical concern for long duration flights to the planets or extended stays aboard space stations. Understanding the extent and temporal relationships of muscle loss is important for the development of effective spaceflight countermeasures. We hypothesized that significant and measurable changes in muscle volume would occur in Shuttle crewmembers following 8 d of weightlessness. MRI was used to obtain the muscle volumes of the calf, thigh and lower back before and after the STS-47 Shuttle mission. Statistical analyses demonstrated that the soleus-gastrocnemius (-6.3%), anterior calf (-3.9%), hamstrings (-8.3%), quadriceps (-6.0%) and intrinsic back (-10.3%) muscles were decreased, p < 0.05, compared to baseline, 24 h after landing. At 2 weeks post recovery, the hamstrings and intrinsic lower back muscles were still below baseline, p < 0.05. These results demonstrate that even short duration spaceflight can result in significant muscle atrophy.

Bacterial chitinolytic communities respond to chitin and pH alteration in soil.

PubMed

Kielak, Anna M; Cretoiu, Mariana Silvia; Semenov, Alexander V; Sørensen, Søren J; van Elsas, Jan Dirk

2013-01-01

Chitin amendment is a promising soil management strategy that may enhance the suppressiveness of soil toward plant pathogens. However, we understand very little of the effects of added chitin, including the putative successions that take place in the degradative process. We performed an experiment in moderately acid soil in which the level of chitin, next to the pH, was altered. Examination of chitinase activities revealed fast responses to the added crude chitin, with peaks of enzymatic activity occurring on day 7. PCR-denaturing gradient gel electrophoresis (DGGE)-based analyses of 16S rRNA and chiA genes showed structural changes of the phylogenetically and functionally based bacterial communities following chitin addition and pH alteration. Pyrosequencing analysis indicated (i) that the diversity of chiA gene types in soil is enormous and (i) that different chiA gene types are selected by the addition of chitin at different prevailing soil pH values. Interestingly, a major role of Gram-negative bacteria versus a minor one of Actinobacteria in the immediate response to the added chitin (based on 16S rRNA gene abundance and chiA gene types) was indicated. The results of this study enhance our understanding of the response of the soil bacterial communities to chitin and are of use for both the understanding of soil suppressiveness and the possible mining of soil for novel enzymes.

The Integrated Impact of Diet On Human Immune Response, the Gut Microbiota, and Nutritional Status During Adaptation to a Spaceflight Analog

NASA Technical Reports Server (NTRS)

Douglas, G. L.; Zwart, S. R.; Young, M.; Kloeris, V.; Crucian, B.; Smith, S. M.; Lorenzi, H.

2017-01-01

Spaceflight impacts human physiology, including well documented immune system dysregulation. Diet, immune function, and the microbiome are interlinked, but diet is the only one of these factors that we have the ability to easily, and significantly, alter on Earth or during flight. As we understand dietary impacts on physiology more thoroughly, we may then improve the spaceflight diet to improve crew health and potentially reduce flight-associated physiological alterations. It is expected that increasing the consumption of fruits and vegetables and bioactive compounds (e.g.,omega-3 fatty acids, lycopene, flavonoids) and therefore enhancing overall nutritional intake from the nominal shelf-stable, fully-processed space food system could serve as a countermeasure to improve human immunological profiles, the taxonomic profile of the gut microbiota, and nutritional status, especially where currently dysregulated during spaceflight. This interdisciplinary study will determine the effect of the current shelf-stable spaceflight diet compared to an "enhanced" shelf-stable spaceflight diet (25% more foods rich in omega-3 fatty acids, lycopene, flavonoids, fruits, and vegetables). The NASA Human Exploration Research Analog (HERA) 2017 missions, consisting of closed chamber confinement, realistic mission simulation, in a high-fidelity mock space vehicle, will serve as a platform to replicate mission stressors and the dysregulated physiology observed in astronauts. Biosampling of crew members will occur at selected intervals, with complete dietary tracking. Outcome measures will include immune markers (e.g., peripheral leukocyte distribution, inflammatory cytokine profiles, T cell function), the taxonomic and metatranscriptomic profile of the gut microbiome, and nutritional status biomarkers and metabolites. Data collection will also include complete dietary tracking. Statistical evaluations will determine physiological and biochemical shifts in relation to nutrient in take and

Reactivation and shedding of cytomegalovirus in astronauts during spaceflight

NASA Technical Reports Server (NTRS)

Mehta, S. K.; Stowe, R. P.; Feiveson, A. H.; Tyring, S. K.; Pierson, D. L.

2000-01-01

The reactivation of cytomegalovirus (CMV) in 71 astronauts was investigated, using polymerase chain reaction. A significantly greater (P<.0001) shedding frequency was found in urine samples from astronauts before spaceflight (10.6%) than in urine from the healthy control subject group (1.2%). Two of 4 astronauts studied during spaceflight shed CMV in urine. A significant increase (P<.0001) in CMV antibody titer, compared with baseline values, was also found 10 days before spaceflight. CMV antibody titer was further increased (P<.001) 3 days after landing, compared with 10 days before the mission. Significant increases in stress hormones were also found after landing. These results demonstrate that CMV reactivation occurred in astronauts before spaceflight and indicate that CMV may further reactivate during spaceflight.

Study protocol to examine the effects of spaceflight and a spaceflight analog on neurocognitive performance: extent, longevity, and neural bases.

PubMed

Koppelmans, Vincent; Erdeniz, Burak; De Dios, Yiri E; Wood, Scott J; Reuter-Lorenz, Patricia A; Kofman, Igor; Bloomberg, Jacob J; Mulavara, Ajitkumar P; Seidler, Rachael D

2013-12-18

Long duration spaceflight (i.e., 22 days or longer) has been associated with changes in sensorimotor systems, resulting in difficulties that astronauts experience with posture control, locomotion, and manual control. The microgravity environment is an important causal factor for spaceflight induced sensorimotor changes. Whether spaceflight also affects other central nervous system functions such as cognition is yet largely unknown, but of importance in consideration of the health and performance of crewmembers both in- and post-flight. We are therefore conducting a controlled prospective longitudinal study to investigate the effects of spaceflight on the extent, longevity and neural bases of sensorimotor and cognitive performance changes. Here we present the protocol of our study. This study includes three groups (astronauts, bed rest subjects, ground-based control subjects) for which each the design is single group with repeated measures. The effects of spaceflight on the brain will be investigated in astronauts who will be assessed at two time points pre-, at three time points during-, and at four time points following a spaceflight mission of six months. To parse out the effect of microgravity from the overall effects of spaceflight, we investigate the effects of seventy days head-down tilted bed rest. Bed rest subjects will be assessed at two time points before-, two time points during-, and three time points post-bed rest. A third group of ground based controls will be measured at four time points to assess reliability of our measures over time. For all participants and at all time points, except in flight, measures of neurocognitive performance, fine motor control, gait, balance, structural MRI (T1, DTI), task fMRI, and functional connectivity MRI will be obtained. In flight, astronauts will complete some of the tasks that they complete pre- and post flight, including tasks measuring spatial working memory, sensorimotor adaptation, and fine motor performance

Study protocol to examine the effects of spaceflight and a spaceflight analog on neurocognitive performance: extent, longevity, and neural bases

PubMed Central

2013-01-01

Background Long duration spaceflight (i.e., 22 days or longer) has been associated with changes in sensorimotor systems, resulting in difficulties that astronauts experience with posture control, locomotion, and manual control. The microgravity environment is an important causal factor for spaceflight induced sensorimotor changes. Whether spaceflight also affects other central nervous system functions such as cognition is yet largely unknown, but of importance in consideration of the health and performance of crewmembers both in- and post-flight. We are therefore conducting a controlled prospective longitudinal study to investigate the effects of spaceflight on the extent, longevity and neural bases of sensorimotor and cognitive performance changes. Here we present the protocol of our study. Methods/design This study includes three groups (astronauts, bed rest subjects, ground-based control subjects) for which each the design is single group with repeated measures. The effects of spaceflight on the brain will be investigated in astronauts who will be assessed at two time points pre-, at three time points during-, and at four time points following a spaceflight mission of six months. To parse out the effect of microgravity from the overall effects of spaceflight, we investigate the effects of seventy days head-down tilted bed rest. Bed rest subjects will be assessed at two time points before-, two time points during-, and three time points post-bed rest. A third group of ground based controls will be measured at four time points to assess reliability of our measures over time. For all participants and at all time points, except in flight, measures of neurocognitive performance, fine motor control, gait, balance, structural MRI (T1, DTI), task fMRI, and functional connectivity MRI will be obtained. In flight, astronauts will complete some of the tasks that they complete pre- and post flight, including tasks measuring spatial working memory, sensorimotor adaptation

Presyncopal/Non-Presyncopal Outcomes of Post Spaceflight Stand Tests are Consistent from Flight to Flight

NASA Technical Reports Server (NTRS)

Martin, D. S.; Meck, J. V.

2004-01-01

The overall prevalence of orthostatic hypotension after short duration (6-18 d) spaceflight is 20% with existing countermeasures. However, it is not known if the outcomes of stand tests for orthostatic tolerance are consistent within individuals on subsequent flights, or if first time fliers are more (or less) likely to experience orthostatic hypotension and presyncope than are veteran astronauts. Fifty astronauts were studied retrospectively. Stand test data, which had been collected before and after spaceflight, were compared from at least two flights for each astronaut. For twenty-five of these astronauts, their first flight in this database was also their first time to fly into space. For the remaining 25, their first flight in this database was their second, third or fourth flight, as data were available. No subject became presyncopal during preflight testing. Of the 50 subjects, 45 (90%) had the same outcome on their first and second fligh ts of this study. Of 14 subjects on whom we had data from a third mission, 12 had the same stand test outcome on all three flights (86% same outcome across three flights). There was no correlation between flight duration and orthostatic tolerance (r = 0.39). These data support the idea that astronauts are predisposed to orthostatic tolerance/intolerance after spaceflight and that this predisposition is not altered by subsequent flights. Flight durations within this data set did not alter the likelihood of orthostatic intolerance and rookie fliers were no more likely to experience orthostatic intolerance than were veteran astronauts.

Spaceflight Safety on the North Coast of America

NASA Technical Reports Server (NTRS)

Ciancone, Michael L.; Havenhill, Maria T.; Terlep, Judith A.

1996-01-01

Spaceflight Safety (SFS) engineers at NASA Lewis Research Center (LeRC) are responsible for evaluating the microgravity fluids and combustion experiments, payloads and facilities developed at NASA LeRC which are manifested for spaceflight on the Space Shuttle, the Russian space station Mir, and/or the International Space Station (ISS). An ongoing activity at NASA LeRC is the comprehensive training of its SFS engineers through the creation and use of safety tools and processes. Teams of SFS engineers worked on the development of an Internet website (containing a spaceflight safety knowledge database and electronic templates of safety products) and the establishment of a technical peer review process (known as the Safety Assurance for Lewis Spaceflight Activities (SALSA) review).

Occupational Surveillance for Spaceflight Exposures

NASA Technical Reports Server (NTRS)

Tarver, William J.

2010-01-01

This slide presentation reviews the importance of longterm occupational health surveillance of astronauts after exposure to the possible hazards of spaceflight. Because there is not much information about long term effects of spaceflight on human health, it is important to identify some of the possible results of exposure to the many possible factors that can influence longterm health impacts. This surveillance also allows for NASA to meet the obligation to care for the astronauts for their lifetime.

Microgravity elicits reproducible alterations in cytoskeletal and metabolic gene and protein expression in space-flown Caenorhabditis elegans

PubMed Central

Higashibata, Akira; Hashizume, Toko; Nemoto, Kanako; Higashitani, Nahoko; Etheridge, Timothy; Mori, Chihiro; Harada, Shunsuke; Sugimoto, Tomoko; Szewczyk, Nathaniel J; Baba, Shoji A; Mogami, Yoshihiro; Fukui, Keiji; Higashitani, Atsushi

2016-01-01

Although muscle atrophy is a serious problem during spaceflight, little is known about the sequence of molecular events leading to atrophy in response to microgravity. We carried out a spaceflight experiment using Caenorhabditis elegans onboard the Japanese Experiment Module of the International Space Station. Worms were synchronously cultured in liquid media with bacterial food for 4 days under microgravity or on a 1-G centrifuge. Worms were visually observed for health and movement and then frozen. Upon return, we analyzed global gene and protein expression using DNA microarrays and mass spectrometry. Body length and fat accumulation were also analyzed. We found that in worms grown from the L1 larval stage to adulthood under microgravity, both gene and protein expression levels for muscular thick filaments, cytoskeletal elements, and mitochondrial metabolic enzymes decreased relative to parallel cultures on the 1-G centrifuge (95% confidence interval (P⩽0.05)). In addition, altered movement and decreased body length and fat accumulation were observed in the microgravity-cultured worms relative to the 1-G cultured worms. These results suggest protein expression changes that may account for the progressive muscular atrophy observed in astronauts. PMID:28725720

A Bactericidal Guanidinomethyl Biaryl That Alters the Dynamics of Bacterial FtsZ Polymerization

PubMed Central

Kaul, Malvika; Parhi, Ajit K.; Zhang, Yongzheng; LaVoie, Edmond J.; Tuske, Steve; Arnold, Eddy; Kerrigan, John E.; Pilch, Daniel S.

2014-01-01

The prevalence of multidrug resistance among clinically significant bacterial pathogens underscores a critical need for the development of new classes of antibiotics with novel mechanisms of action. Here we describe the synthesis and evaluation of a guanidinomethyl biaryl compound {1-((4′-(tert-butyl)-[1,1′-biphenyl]-3-yl)methyl)guanidine} that targets the bacterial cell division protein FtsZ. In vitro studies with various bacterial FtsZ proteins reveal that the compound alters the dynamics of FtsZ self-polymerization via a stimulatory mechanism, while minimally impacting the polymerization of tubulin, the closest mammalian homologue of FtsZ. The FtsZ binding site of the compound is identified through a combination of computational and mutational approaches. The compound exhibits a broad spectrum of bactericidal activity, including activity against the multidrug-resistant pathogens methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), while also exhibiting a minimal potential to induce resistance. Taken together, our results highlight the compound as a promising new FtsZ-targeting bactericidal agent. PMID:23050700

Experimental Modification of Rat Pituitary Prolactin Cell Function During and After Spaceflight

NASA Technical Reports Server (NTRS)

Hymer, W. C.; Salada, T.; Avery, L.; Grindeland, R. E.

1996-01-01

Experimental modification of rat pituitary prolactin cell function during and after spaceflight. This study was done to evaluate the effects of microgravity on prolactin (PRL) cells of the male rat pituitary gland. We used the identical passive closed-vial cell culture system that was described for the culture of growth hormone cells (W C. Hymer, R. E. Grindeland, T. Salada, P. Nye, E. Grossman, and R Lane). After an 8-day spaceflight, all flight media (containing released PRL), as well as extracts (containing intracellular PRL), contained significantly lower amounts of immunoreactive PRL than their corresponding ground control samples. On the other hand, these same samples, when assessed for their biological activities by two different in vitro lymphocyte assays, yielded disparate results that may reflect posttranslational modifications to the hormone molecule. Other data showed that: (1) the apparent molecular weights of released PRL molecules were not altered by microgravity; but (2) the region from which the PRL cells came (dorsal or ventral) made a significant difference in the amount and activity of PRL released from the flight cells. Because there is much current interest in the role that PRL may play in the regulation of the immune system and because changes in both cellular and humoral immunity accompany spaceflight, this study could help define future microgravity research in this area.

Joint inflight biomedical experiments performed during the ASTP spaceflight. [bacteriological experiments

NASA Technical Reports Server (NTRS)

Taylor, G. R.; Rogers, T. D.; Brower, M. E.; Kropp, K.

1976-01-01

Two joint inflight biomedical experiments were conducted during the unique Apollo-Soyuz Test Project (ASTP) spaceflight. One experiment evaluated rhythmicity of spore production of Streptomyces levoris. The other evaluated components of the infectious disease process by measuring alteration in: (1) the composition of the microbial population inhabiting USA and USSR crewmembers and spacecraft; (2) the ability of each crewmember's defense mechanism to resist infection; and (3) the ability of certain microorganisms to originate infections. These two experiments are described and the major results discussed.

Research on sleep, circadian rhythms and aging - Applications to manned spaceflight

NASA Technical Reports Server (NTRS)

Czeisler, Charles A.; Chiasera, August J.; Duffy, Jeanne F.

1991-01-01

Disorders of sleep and circadian rhythmicity are characteristic of both advancing age and manned spaceflight. Sleep fragmentation, reduced nocturnal sleep tendency and sleep efficiency, reduced daytime alertness, and increased daytime napping are common to both of these conditions. Recent research on the pathophysiology and treatment of disrupted sleep in older people has led to a better understanding of how the human circadian pacemaker regulates the timing of the daily sleep-wake cycle and how it responds to the periodic changes in the light-dark cycle to which we are ordinarily exposed. These findings have led to new treatments for some of the sleep disorders common to older individuals, using carefully timed exposure to bright light and darkness to manipulate the phase and/or amplitude of the circadian timing system. These insights and treatment approaches have direct applications in the design of countermeasures allowing astronauts to overcome some of the challenges which manned spaceflight poses for the human circadian timing system. We have conducted an operational feasibility study on the use of scheduled exposure to bright light and darkness prior to launch in order to facilitate adaptation of the circadian system of a NASA Space Shuttle crew to the altered sleep-wake schedule required for their mission. The results of this study illustrate how an understanding of the properties of the human circadian timing system and the consequences of circadian disruption can be applied to manned spaceflight.

Research on sleep, circadian rhythms and aging: applications to manned spaceflight.

PubMed

Czeisler, C A; Chiasera, A J; Duffy, J F

1991-01-01

Disorders of sleep and circadian rhythmicity are characteristic of both advancing age and manned spaceflight. Sleep fragmentation, reduced nocturnal sleep tendency and sleep efficiency, reduced daytime alertness, and increased daytime napping are common to both of these conditions. Recent research on the pathophysiology and treatment of disrupted sleep in older people has led to a better understanding of how the human circadian pacemaker regulates the timing of the daily sleep-wake cycle and how it responds to the periodic changes in the light-dark cycle to which we are ordinarily exposed. These findings have led to new treatments for some of the sleep disorders common to older individuals, using carefully timed exposure to bright light and darkness to manipulate the phase and/or amplitude of the circadian timing system. These insights and treatment approaches have direct applications in the design of countermeasures allowing astronauts to overcome some of the challenges which manned spaceflight poses for the human circadian timing system. We have conducted an operational feasibility study on the use of scheduled exposure to bright light and darkness prior to launch in order to facilitate adaptation of the circadian system of a NASA space shuttle crew to the altered sleep-wake schedule required for their mission. The results of this study illustrate how an understanding of the properties of the human circadian timing system and the consequences of circadian disruption can be applied to manned spaceflight.

Broad-spectrum antibiotic or G-CSF as potential countermeasures for impaired control of bacterial infection associated with an SPE exposure during spaceflight.

PubMed

Li, Minghong; Holmes, Veronica; Ni, Houping; Sanzari, Jenine K; Romero-Weaver, Ana L; Lin, Liyong; Carabe-Fernandez, Alejandro; Diffenderfer, Eric S; Kennedy, Ann R; Weissman, Drew

2015-01-01

A major risk for astronauts during prolonged space flight is infection as a result of the combined effects of microgravity, situational and confinement stress, alterations in food intake, altered circadian rhythm, and radiation that can significantly impair the immune system and the body's defense systems. We previously reported a massive increase in morbidity with a decrease in the ability to control a bacterial challenge when mice were maintained under hindlimb suspension (HS) conditions and exposed to solar particle event (SPE)-like radiation. HS and SPE-like radiation treatment alone resulted in a borderline significant increase in morbidity. Therefore, development and testing of countermeasures that can be used during extended space missions in the setting of exposure to SPE radiation becomes a serious need. In the present study, we investigated the efficacy of enrofloxacin (an orally bioavailable antibiotic) and Granulocyte colony stimulating factor (G-CSF) (Neulasta) on enhancing resistance to Pseudomonas aeruginosa infection in mice subjected to HS and SPE-like radiation. The results revealed that treatment with enrofloxacin or G-CSF enhanced bacterial clearance and significantly decreased morbidity and mortality in challenged mice exposed to suspension and radiation. These results establish that antibiotics, such as enrofloxacin, and G-CSF could be effective countermeasures to decrease the risk of bacterial infections after exposure to SPE radiation during extended space flight, thereby reducing both the risk to the crew and the danger of mission failure.

Spaceflight Associated Apoptosis

NASA Technical Reports Server (NTRS)

Ichiki, Albert T.; Gibson, Linda A.; Allebban, Zuhair

1996-01-01

Lymphoid tissues have been shown to atrophy in rats flown on Russian spaceflights. Histological examination indicated evidence for cell degradation. Lymphoid tissues from rats flown on Spacelab Life Sciences-2 mission were analyzed for apoptosis by evidence of fragmented lymphocytes, which could be engulfed by macrophages, or DNA strand breaks using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. Apoptosis was not detected in the thymus and spleen collected inflight or from the synchronous ground rats but was detected in the thymus, spleen and inguinal lymph node of the flight animals on recovery. These results indicate that the apoptosis observed in the lymphatic tissues of the rats on recovery could have been induced by the gravitational stress of reentry, corroborating the findings from the early space-flight observations.

Vizantin inhibits bacterial adhesion without affecting bacterial growth and causes Streptococcus mutans biofilm to detach by altering its internal architecture.

PubMed

Takenaka, Shoji; Oda, Masataka; Domon, Hisanori; Ohsumi, Tatsuya; Suzuki, Yuki; Ohshima, Hayato; Yamamoto, Hirofumi; Terao, Yutaka; Noiri, Yuichiro

2016-11-11

An ideal antibiofilm strategy is to control both in the quality and quantity of biofilm while maintaining the benefits derived from resident microflora. Vizantin, a recently developed immunostimulating compound, has also been found to have antibiofilm property. This study evaluated the influence on biofilm formation of Streptococcus mutans in the presence of sulfated vizantin and biofilm development following bacterial adhesion on a hydroxyapatite disc coated with sulfated vizantin. Supplementation with sulfated vizantin up to 50 μM did not affect either bacterial growth or biofilm formation, whereas 50 μM sulfated vizantin caused the biofilm to readily detach from the surface. Sulfated vizantin at the concentration of 50 μM upregulated the expression of the gtfB and gtfC genes, but downregulated the expression of the gtfD gene, suggesting altered architecture in the biofilm. Biofilm development on the surface coated with sulfated vizantin was inhibited depending on the concentration, suggesting prevention from bacterial adhesion. Among eight genes related to bacterial adherence in S. mutans, expression of gtfB and gtfC was significantly upregulated, whereas the expression of gtfD, GbpA and GbpC was downregulated according to the concentration of vizantin, especially with 50 μM vizantin by 0.8-, 0.4-, and 0.4-fold, respectively. These findings suggest that sulfated vizantin may cause structural degradation as a result of changing gene regulation related to bacterial adhesion and glucan production of S. mutans. Copyright © 2016 Elsevier Inc. All rights reserved.

[Primary effects on Isatis indigotica after spaceflight].

PubMed

Chen, Xiang-dong; Lan, Jin; Wang, Xiao-guang

2007-04-01

Isatis indigotica carried by the Chinese first spaceship "Shenzhou" was studied in order to find the mutation after spaceflight. TLC differentiation experiments showed no distinct discrepancy among the samples of spaceflight and non-space-flight, and the same color spot appeared corresponding to the location of the arginine. Isoenzymes of esterase and peroxidase were studied with PAGE. Isoenzymes of esterase were difference among the samples. To peroxidases, little difference was found with them. The ratio of dry weight and extract contents showed out the mutation has emerged after spaceflight, but some characters were unstable. It is necessary for further study.

Impervious Surfaces Alter Soil Bacterial Communities in Urban Areas: A Case Study in Beijing, China

PubMed Central

Hu, Yinhong; Dou, Xiaolin; Li, Juanyong; Li, Feng

2018-01-01

The rapid expansion of urbanization has caused land cover change, especially the increasing area of impervious surfaces. Such alterations have significant effects on the soil ecosystem by impeding the exchange of gasses, water, and materials between soil and the atmosphere. It is unclear whether impervious surfaces have any effects on soil bacterial diversity and community composition. In the present study, we conducted an investigation of bacterial communities across five typical land cover types, including impervious surfaces (concrete), permeable pavement (bricks with round holes), shrub coverage (Buxus megistophylla Levl.), lawns (Festuca elata Keng ex E. Alexeev), and roadside trees (Sophora japonica Linn.) in Beijing, to explore the response of bacteria to impervious surfaces. The soil bacterial communities were addressed by high-throughput sequencing of the bacterial 16S rRNA gene. We found that Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes, Chloroflexi, and Firmicutes were the predominant phyla in urban soils. Soil from impervious surfaces presented a lower bacterial diversity, and differed greatly from other types of land cover. Soil bacterial diversity was predominantly affected by Zn, dissolved organic carbon (DOC), and soil moisture content (SMC). The composition of the bacterial community was similar under shrub coverage, roadside trees, and lawns, but different from beneath impervious surfaces and permeable pavement. Variance partitioning analysis showed that edaphic properties contributed to 12% of the bacterial community variation, heavy metal pollution explained 3.6% of the variation, and interaction between the two explained 33% of the variance. Together, our data indicate that impervious surfaces induced changes in bacterial community composition and decrease of bacterial diversity. Interactions between edaphic properties and heavy metals were here found to change the composition of the bacterial community and diversity across

Contribution of Spaceflight Environmental Factors to Vision Risks

NASA Technical Reports Server (NTRS)

Zanello, Susana

2012-01-01

The recognition of a risk of visual impairment and intracranial pressure increase as a result of spaceflight has directed our attention and research efforts to the eye. While the alterations observed in astronauts returning from long duration missions include reportable vision and neuroanatomical changes observed by non-invasive methods, other effects and subsequent tissue responses at the molecular and cellular level can only be studied by accessing the tissue itself. As a result of this need, several studies are currently taking place that use animal models for eye research within the HHC Element. The implementation of these studies represents a significant addition to the capabilities of the biomedical research laboratories within the SK3 branch at JSC.

The Spaceflight Revolution Revisted

NASA Astrophysics Data System (ADS)

Bainbridge, William Sims

2002-01-01

There are two models of the future of spaceflight, and there are two theories of how that future might be achieved. The first model of spaceflight assumes that we have already achieved most of what is worth achieving in space, whereas the second imagines it will be possible to build a truly interplanetary civilization in which most human beings live elsewhere than on Earth. The first theory holds that progress comes incrementally from the inexorable working of free markets and political systems, whereas the second believes that revolutionary transformations must sometimes be accomplished by social movements that transcend the ordinary institutions and motivations of mundane existence.

Effect Of Spaceflight On Microbial Gene Expression And Virulence: Preliminary Results From Microbe Payload Flown On-Board STS-115

NASA Technical Reports Server (NTRS)

Wilson, J. W.; HonerzuBentrup, K,; Schurr, M. J.; Buchanan, K.; Morici, L.; Hammond, T.; Allen, P.; Baker, C.; Ott, C. M.; Nelman-Gonzalez M.;

On Representative Spaceflight Instrument and Associated Instrument Sensor Web Framework

NASA Technical Reports Server (NTRS)

Kizhner, Semion; Patel, Umeshkumar; Vootukuru, Meg

2007-01-01

Sensor Web-based adaptation and sharing of space flight mission resources, including those of the Space-Ground and Control-User communication segment, could greatly benefit from utilization of heritage Internet Protocols and devices applied for Spaceflight (SpaceIP). This had been successfully demonstrated by a few recent spaceflight experiments. However, while terrestrial applications of Internet protocols are well developed and understood (mostly due to billions of dollars in investments by the military and industry), the spaceflight application of Internet protocols is still in its infancy. Progress in the developments of SpaceIP-enabled instrument components will largely determine the SpaceIP utilization of those investments and acceptance in years to come. Likewise SpaceIP, the development of commercial real-time and instrument colocated computational resources, data compression and storage, can be enabled on-board a spacecraft and, in turn, support a powerful application to Sensor Web-based design of a spaceflight instrument. Sensor Web-enabled reconfiguration and adaptation of structures for hardware resources and information systems will commence application of Field Programmable Arrays (FPGA) and other aerospace programmable logic devices for what this technology was intended. These are a few obvious potential benefits of Sensor Web technologies for spaceflight applications. However, they are still waiting to be explored. This is because there is a need for a new approach to spaceflight instrumentation in order to make these mature sensor web technologies applicable for spaceflight. In this paper we present an approach in developing related and enabling spaceflight instrument-level technologies based on the new concept of a representative spaceflight Instrument Sensor Web (ISW).

Attenuation of Streptococcus suis virulence by the alteration of bacterial surface architecture

PubMed Central

Feng, Youjun; Cao, Min; Shi, Jie; Zhang, Huimin; Hu, Dan; Zhu, Jing; Zhang, Xianyun; Geng, Meiling; Zheng, Feng; Pan, Xiuzhen; Li, Xianfu; Hu, Fuquan; Tang, Jiaqi; Wang, Changjun

2012-01-01

NeuB, a sialic acid synthase catalyzes the last committed step of the de novo biosynthetic pathway of sialic acid, a major element of bacterial surface structure. Here we report a functional NeuB homologue of Streptococcus suis, a zoonotic agent, and systematically address its molecular and immunological role in bacterial virulence. Disruption of neuB led to thinner capsules and more susceptibility to pH, and cps2B inactivation resulted in complete absence of capsular polysaccharides. These two mutants both exhibited increased adhesion and invasion to Hep-2 cells and improved sensibility to phagocytosis. Not only do they retain the capability of inducing the release of host pro-inflammatory cytokines, but also result in the faster secretion of IL-8. Easier cleaning up of the mutant strains in whole blood is consistent with virulence attenuation seen with experimental infections of both mice and SPF-piglets. Therefore we concluded that altered architecture of S. suis surface attenuates its virulence. PMID:23050094

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto, with Instrumentation Technology Associates, Inc., works on an experiment found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-06

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto, with Instrumentation Technology Associates, Inc., works on an experiment found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

Spaceflight Microbiology: Benefits for Long Duration Spaceflight and Our Understanding of Microorganisms on Earth

NASA Technical Reports Server (NTRS)

Ott, C. Mark

2014-01-01

Spaceflight microbiology is composed of both operational and experimental components that complement each other in our understanding of microbial interactions and their responses in the microgravity of spaceflight. Operationally, efforts to mitigate microbiological risk to the crew and the spacecraft have historically focused on minimizing the number of detectable organisms, relying heavily on preventative measures, including appropriate vehicle design, crew quarantine prior to flight, and stringent microbial monitoring. Preflight monitoring targets have included the astronauts, spaceflight foods, potable water systems, the vehicle air and surfaces, and the cargo carried aboard the spacecraft. This approach has been very successful for earlier missions; however, the construction and long-term habitation of the International Space Station (ISS) has created the need for additional inflight monitoring of the environment and potable water systems using hardware designed for both in-flight microbial enumeration and sample collection and return to Earth. In addition to operational activities, the ISS is providing a research platform to advance our understanding of microbiomes in the built environment. Adding to the research possibilities of this system are multiple reports of unique changes in microbial gene expression and phenotypic responses, including virulence and biofilm formation, in response to spaceflight culture. The tremendous potential of the ISS research platform led the National Research Council to recommend that NASA utilize the ISS as a microbial observatory. Collectively, the findings from operational and research activities on the ISS are expected to both enable future space exploration and translate to basic and applied research on Earth.

Changes of Cytokines during a Spaceflight Analog - a 45-Day Head-Down Bed Rest

PubMed Central

Zhang, Shusong; Pang, Xuewen; Liu, Hongju; Li, Li; Sun, Xiuyuan; Zhang, Yu; Wu, Hounan; Chen, Xiaoping; Ge, Qing

2013-01-01

Spaceflight is associated with deregulation in the immune system. Head-down bed rest (HDBR) at -6° is believed to be the most practical model for examining multi-system responses to microgravity in humans during spaceflight. In the present study, a 45-day HDBR was performed to investigate the alterations in human immune cell distributions and their functions in response to various stimuli. The effect of countermeasure, Rhodiola rosea (RR) treatment, was also examined. A significant decrease of interferon-γ (IFN-γ) and interleukin-17 (IL-17) productions by activated T cells, increase of IL-1β and IL-18 by activated B and myeloid cells were observed during HDBR. The upregulation of serum cortisol was correlated with the changes of IL-1 family cytokines. In addition, a significant increase of memory T and B cell and regulatory T cells (Treg) were also detected. The uptake of RR further decreased IFN-γ level and slowed down the upregulation of IL-1 family cytokines. These data suggest that for prolonged HDBR and spaceflight, the decreased protective T cell immunity and enhanced proinflammatory cytokines should be closely monitored. The treatment with RR may play an important role in suppressing proinflammatory cytokines but not in boosting protective T cell immunity. PMID:24143230

Behavioral and health implications of civilian spaceflight.

PubMed

Wichman, Harvey A

2005-06-01

The current enthusiasm over the prospect of space tourism and the belief among many that such civilian spaceflight is imminent are characterized herein. There are many concerns about screening and certifying passengers for future spaceflight. Efforts by several organizations to propose such screening are cited. The problem with some of these proposals, which treat all types of spaceflight the same, is that they are so restrictive that too few people would be eligible for space travel to have a viable tourism industry. However, not all types of spaceflight are the same, so the distinctions between them need to be clarified. Of the five types of spaceflight described, one is proposed as the most likely to be the first significant phase of space tourism: long-term microgravity flight in low Earth orbit. But because of human problems with long-term exposure to microgravity, this phase requires rather conservative screening and extensive training. However, prior to discussing the passenger issues related to this early phase of space tourism, the reasons why Earth-like gravity, as well as microgravity, must be made available to spacefarers before space tourism can take place on a grand scale need to be explained. Finally, major passenger medical and behavioral issues of the first phase of orbital space tourism-long-term microgravity flight-are discussed.

Cardiovascular responses to spaceflight

NASA Technical Reports Server (NTRS)

Nicogossian, A.; Pool, S. L.; Rambaut, P. C.

1983-01-01

The cardiovascular system's adaptive changes during and after spaceflight are discussed. Cephalic fluid shifts are demonstrated by photographs along with calf girth and leg volume changes. Inflight measurements show an increase in average resting heart rate and systolic blood pressure, and a sympathetic-parasympathetic neural imbalance. Postflight findings include a small but reversible decrease in the left ventricular muscle mass. Since 1980, NASA's research has emphasized cardiovascular deconditioning and countermeasures: hemodynamic changes, endocrine and neurohumoral aspects, etiologic factors, and lower body negative pressure devices. Though human beings acclimate to the space environment, questions concerning the immediate and long-term aspects of spaceflight need to be answered for adequate planning of extended space missions.

The Integrated Impact of Diet on Human Immune Response, the Gut Microbiota, and Nutritional Status During Adaptation to a Spaceflight Analog

NASA Technical Reports Server (NTRS)

Douglas, G. L.; Zwart, S. R.; Young, M.; Kloeris, V.; Crucian, B.; Smith, S. M.; Lorenzi, H.

2018-01-01

Spaceflight impacts human physiology, including well documented immune system dysregulation. Diet, immune function, and the microbiome are interlinked, but diet is the only one of these factors that we have the ability to easily, and significantly, alter on Earth or during flight. As we understand dietary impacts on physiology more thoroughly, we may then improve the spaceflight diet to improve crew health and potentially reduce spaceflight-associated physiological alterations. It is expected that increasing the consumption of fruits and vegetables and bioactive compounds (e.g., omega-3 fatty acids, lycopene, flavonoids) and therefore enhancing overall nutritional intake from the nominal shelf-stable, fully-processed space food system could serve as a countermeasure to improve human immunological profiles, the taxonomic profile of the gut microbiota, and nutritional status, especially where currently dysregulated during spaceflight. This interdisciplinary study will determine the effect of the current shelf-stable spaceflight diet compared to an "enhanced" shelf-stable spaceflight diet (25% more foods rich in omega-3 fatty acids, lycopene, flavonoids, and more fruits, and vegetables in general). The NASA Human Exploration Research Analog (HERA) 2017 missions, consisting of four 45-day missions with closed chamber confinement and realistic mission simulation in a high-fidelity mock space vehicle, will serve as a platform to replicate mission stressors and the effects on crew biochemistry, immunology, and the gut microbiome. Bio sampling of crewmembers is scheduled for selected intervals pre- and in-mission. Data collection also includes dietary intake recording. Outcome measures will include immune markers (e.g., peripheral leukocyte distribution, inflammatory cytokine profiles, T cell function), the taxonomic and metatranscriptomic profile of the gut microbiome, and nutritional status biomarkers and metabolites. Statistical evaluations will determine physiological

The SCD - Stem Cell Differentiation ESA Project: Preparatory Work for the Spaceflight Mission

NASA Astrophysics Data System (ADS)

Versari, Silvia; Barenghi, Livia; van Loon, Jack; Bradamante, Silvia

2016-04-01

Due to spaceflight, astronauts experience serious, weightlessness-induced bone loss because of an unbalanced process of bone remodeling that involves bone marrow mesenchymal stem cells (BMSCs), as well as osteoblasts, osteocytes, and osteoclasts. The effects of microgravity on osteo-cells have been extensively studied, but it is only recently that consideration has been given to the role of BMSCs. Previous researches indicated that human BMSCs cultured in simulated microgravity (sim-μg) alter their proliferation and differentiation. The spaceflight opportunities for biomedical experiments are rare and suffer from a number of operative constraints that could bias the validity of the experiment itself, but remain a unique opportunity to confirm and explain the effects due to microgravity, that are only partially activated/detectable in simulated conditions. For this reason, we carefully prepared the SCD - STEM CELLS DIFFERENTIATION experiment, selected by the European Space Agency (ESA) and now on the International Space Station (ISS). Here we present the preparatory studies performed on ground to adapt the project to the spaceflight constraints in terms of culture conditions, fixation and storage of human BMSCs in space aiming at satisfying the biological requirements mandatory to retrieve suitable samples for post-flight analyses. We expect to understand better the molecular mechanisms governing human BMSC growth and differentiation hoping to outline new countermeasures against astronaut bone loss.

Review of primary spaceflight-induced and secondary reloading-induced changes in slow antigravity muscles of rats

NASA Astrophysics Data System (ADS)

Riley, D. A.

We have examined the light and electron microscopic properties of hindlimb muscles of rats flown in space for 1-2 weeks on Cosmos biosatellite flights 1887 and 2044 and Space Shuttle missions Spacelab-3, Spacelab Life Sciences-1 and Spacelab Life Sciences-2. Tissues were obtained both inflight and postflight permitting definition of primary microgravity-induced changes and secondary reentry and gravity reloading-induced alterations. Spaceflight causes atrophy and expression of fast fiber characteristics in slow antigravity muscles. The stresses of reentry and reloading reveal that atrophic muscles show increased susceptibility to interstitial edema and ischemic-anoxic necrosis as well as muscle fiber tearing with disruption of contractile proteins. These results demonstrate that the effects of spaceflight on skeletal muscle are multifaceted, and major changes occur both inflight and following return to Earth's gravity.

Review of primary spaceflight-induced and secondary reloading-induced changes in slow antigravity muscles of rats.

PubMed

Riley, D A

1998-01-01

We have examined the light and electron microscopic properties of hindlimb muscles of rats flown in space for 1-2 weeks on Cosmos biosatellite flights 1887 and 2044 and Space Shuttle missions Spacelab-3, Spacelab Life Sciences-1 and Spacelab Life Sciences-2. Tissues were obtained both inflight and postflight permitting definition of primary microgravity-induced changes and secondary reentry and gravity reloading-induced alterations. Spaceflight causes atrophy and expression of fast fiber characteristics in slow antigravity muscles. The stresses of reentry and reloading reveal that atrophic muscles show increased susceptibility to interstitial edema and ischemic-anoxic necrosis as well as muscle fiber tearing with disruption of contractile proteins. These results demonstrate that the effects of spaceflight on skeletal muscle are multifaceted, and major changes occur both inflight and following return to Earth's gravity.

2015 Sensorimotor Risk Standing Review Panel Evidence and Status Review For: the Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Spaceflight

NASA Technical Reports Server (NTRS)

Steinberg, Susan

2015-01-01

The 2015 Sensorimotor Risk Standing Review Panel (from here on referred to as the SRP) participated in a WebEx/teleconference with members of the Human Health Countermeasures (HHC) Element, representatives from the Human Research Program (HRP), NASA Headquarters, and NASA Research and Education Support Services (NRESS) on December 17, 2015 (list of participants is in Section VI of this report). The SRP reviewed the new Evidence Report for the Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Spaceflight (from here on referred to as the 2015 Sensorimotor Evidence Report), and also received a status review of the Risk. The opening section of the 2015 Sensorimotor Evidence Report provides written descriptions of various incidents that have occurred during space missions. In most of these incidents, the main underlying contributing factors are not easy to identify unambiguously. For example, in section 1.9, a number of falls occurred while astronauts were walking on the moon. It is not clear to the SRP, however, why they fell. It is only possible to extrapolate from likely specific psychophysical or physiological abnormalities, but how these abnormalities were determined, and how they were directly responsible for the falls is unclear to the SRP. Section 2.1.2 on proprioception is very interesting, but the functional significance of the abnormalities detected is not clear. The SRP sees this as a problem throughout the report: a mapping between the component abnormalities identified and the holistic behaviors that are most relevant, for example, controlling the vehicle, and locomotion during egress, is generally lacking. The SRP thinks the cognitive section is too strongly focused on vestibular functioning. The SRP questions the notion that the main cognitive effects are mainly attributable to reversible vestibular changes induced by spaceflight. The SRP thinks that there can also

The DNA damage response of C. elegans affected by gravity sensing and radiosensitivity during the Shenzhou-8 spaceflight.

PubMed

Gao, Ying; Xu, Dan; Zhao, Lei; Sun, Yeqing

2017-01-01

Space radiation and microgravity are recognized as primary and inevitable risk factors for humans traveling in space, but the reports regarding their synergistic effects remain inconclusive and vary across studies due to differences in the environmental conditions and intrinsic biological sensitivity. Thus, we studied the synergistic effects on transcriptional changes in the global genome and DNA damage response (DDR) by using dys-1 mutant and ced-1 mutant of C. elegans, which respectively presented microgravity-insensitivity and radiosensitivity when exposure to spaceflight condition (SF) and space radiation (SR). The dys-1 mutation induced similar transcriptional changes under both conditions, including the transcriptional distribution and function of altered genes. The majority of alterations were related to metabolic shift under both conditions, including transmembrane transport, lipid metabolic processes and proteolysis. Under SF and SR conditions, 12/14 and 10/13 altered pathways, respectively, were both grouped in the metabolism category. Out of the 778 genes involved in DDR, except eya-1 and ceh-34, 28 altered genes in dys-1 mutant showed no predicted protein interactions, or anti-correlated miRNAs during spaceflight. The ced-1 mutation induced similar changes under SF and SR; however, these effects were stronger than those of the dys-1 mutant. The additional genes identified were related to phosphorous/phosphate metabolic processes and growth rather than, metabolism, especially for environmental information processing under SR. Although the DDR profiles were significantly changed under both conditions, the ced-1 mutation favored DNA repair under SF and apoptosis under SR. Notably, 37 miRNAs were predicted to be involved in the DDR. Our study indicates that, the dys-1 mutation reduced the transcriptional response to SF, and the ced-1 mutation increased the response to SR, when compared with the wild type C. elegans. Although some effects were due to

Spaceflight Affects Postnatal Development of the Aortic Wall in Rats

PubMed Central

Yamasaki, Masao; Waki, Hidefumi; Miyake, Masao; Nagayama, Tadanori; Miyamoto, Yukako; Wago, Haruyuki; Okouchi, Toshiyasu; Shimizu, Tsuyoshi

2014-01-01

We investigated effect of microgravity environment during spaceflight on postnatal development of the rheological properties of the aorta in rats. The neonate rats were randomly divided at 7 days of age into the spaceflight, asynchronous ground control, and vivarium control groups (8 pups for one dam). The spaceflight group rats at 9 days of age were exposed to microgravity environment for 16 days. A longitudinal wall strip of the proximal descending thoracic aorta was subjected to stress-strain and stress-relaxation tests. Wall tensile force was significantly smaller in the spaceflight group than in the two control groups, whereas there were no significant differences in wall stress or incremental elastic modulus at each strain among the three groups. Wall thickness and number of smooth muscle fibers were significantly smaller in the spaceflight group than in the two control groups, but there were no significant differences in amounts of either the elastin or collagen fibers among the three groups. The decreased thickness was mainly caused by the decreased number of smooth muscle cells. Plastic deformation was observed only in the spaceflight group in the stress-strain test. A microgravity environment during spaceflight could affect postnatal development of the morphological and rheological properties of the aorta. PMID:25210713

Bioaugmentation of Hydrogenispora ethanolica LX-B affects hydrogen production through altering indigenous bacterial community structure.

PubMed

Yang, Zhiman; Guo, Rongbo; Shi, Xiaoshuang; He, Shuai; Wang, Lin; Dai, Meng; Qiu, Yanling; Dang, Xiaoxiao

2016-07-01

Bioaugmentation can facilitate hydrogen production from complex organic substrates, but it still is unknown how indigenous microbial communities respond to the added bacteria. Here, using a Hydrogenispora ethanolica LX-B (named as LX-B) bioaugmentation experiments, the distribution of metabolites and the responses of indigenous bacterial communities were investigated via batch cultivation (BC) and repeated batch cultivation (RBC). In BC the LX-B/sludge ratio of 0.12 achieved substantial high hydrogen yield, which was over twice that of control. In RBC one-time bioaugmentation and repeated batch bioaugmentation of LX-B resulted in the hydrogen yield that was average 1.2-fold and 0.8-fold higher than that in control, respectively. This improved hydrogen production performance mainly benefited from a shift in composition of the indigenous bacterial community caused by LX-B bioaugmentation. The findings represented an important step in understanding the relationship between bioaugmentation, a shift in bacterial communities, and altered bioreactor performance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preflight screening techniques for centrifuge-simulated suborbital spaceflight.

PubMed

Pattarini, James M; Blue, Rebecca S; Castleberry, Tarah L; Vanderploeg, James M

2014-12-01

Historically, space has been the venue of the healthy individual. With the advent of commercial spaceflight, we face the novel prospect of routinely exposing spaceflight participants (SPFs) with multiple comorbidities to the space environment. Preflight screening procedures must be developed to identify those individuals at increased risk during flight. We examined the responses of volunteers to centrifuge accelerations mimicking commercial suborbital spaceflight profiles to evaluate how potential SFPs might tolerate such forces. We evaluated our screening process for medical approval of subjects for centrifuge participation for applicability to commercial spaceflight operations. All registered subjects completed a medical questionnaire, physical examination, and electrocardiogram. Subjects with identified concerns including cardiopulmonary disease, hypertension, and diabetes were required to provide documentation of their conditions. There were 335 subjects who registered for the study, 124 who completed all prescreening, and 86 subjects who participated in centrifuge trials. Due to prior medical history, five subjects were disqualified, most commonly for psychiatric reasons or uncontrolled medical conditions. Of the subjects approved, four individuals experienced abnormal physiological responses to centrifuge profiles, including one back strain and three with anxiety reactions. The screening methods used were judged to be sufficient to identify individuals physically capable of tolerating simulated suborbital flight. Improved methods will be needed to identify susceptibility to anxiety reactions. While severe or uncontrolled disease was excluded, many subjects successfully participated in centrifuge trials despite medical histories of disease that are disqualifying under historical spaceflight screening regimes. Such screening techniques are applicable for use in future commercial spaceflight operations.

Effect of Spaceflight on the Functions of NK and LAK Cells

NASA Technical Reports Server (NTRS)

Pierson, Duane L.; Grimm, Elizabeth A.; Pierson, Duane L.; Paloski, W. H. (Technical Monitor)

1999-01-01

Spaceflight-associated stress alters some aspects of the human immune response. In this study, we determined the effects of 10 days aboard the Space Shuttle on the cytotoxic activity of NK and LAK cells. The subjects of this study were crewmembers of two 10-day shuttle flights. Ten-ml blood specimens were obtained from ten astronauts 10 days before launch, immediately after landing, and 3 days after landing. PBMCs were separated from the blood specimens and stored at -800 C. All PBMCs were thawed simultaneously, and the cytotoxic activities of NK and LAK cells were measured by a 4-hour Cr-51 release assay. K562 cells were used to assess NK-cell cytotoxicity. After 4 days of IL-2 activation, the LAK cell cytotoxic activity was determined using K562 and Daudi cells as the target cells. NK-cell cytotoxicity was decreased at landing (p less than 0.0005) in 9/10 astronauts, and in most cases recovered to preflight levels by 3 days after landing; NK-cell cytotoxicity was increased in one astronaut at landing. LAK cytotoxic activity against K562 cells was decreased at landing in 6/10 astronauts (p=0.018), and activity against Daudi cells was decreased in 7/10 astronauts (p=0.01). Phenotyping of PBMCs and LAK cells showed alterations in some surface markers and adhesion molecules (CD1 1 b, CD1 1 c, CD1 1 a, CD1 6, L-Selectin and CD3). Thus spaceflight leads to a decrease in the functions of NK and LAK cells in most astronauts.

Spaceflight induced changes in the human proteome.

PubMed

Kononikhin, Alexey S; Starodubtseva, Natalia L; Pastushkova, Lyudmila Kh; Kashirina, Daria N; Fedorchenko, Kristina Yu; Brhozovsky, Alexander G; Popov, Igor A; Larina, Irina M; Nikolaev, Evgeny N

2017-01-01

Spaceflight is one of the most extreme conditions encountered by humans: Individuals are exposed to radiation, microgravity, hypodynamia, and will experience isolation. A better understanding of the molecular processes induced by these factors may allow us to develop personalized countermeasures to minimize risks to astronauts. Areas covered: This review is a summary of literature searches from PubMed, NASA, Roskosmos and the authors' research experiences and opinions. The review covers the available proteomic data on the effects of spaceflight factors on the human body, including both real space missions and ground-based model experiments. Expert commentary: Overall, the authors believe that the present background, methodology and equipment improvements will enhance spaceflight safety and support accumulation of new knowledge on how organisms adapt to extreme conditions.

NASA Human Spaceflight Conjunction Assessment: Recent Conjunctions of Interest

NASA Technical Reports Server (NTRS)

Browns, Ansley C.

2010-01-01

This viewgraph presentation discusses a brief history of NASA Human Spaceflight Conjunction Assessment (CA) activities, an overview of NASA CA process for ISS and Shuttle, and recent examples from Human Spaceflight conjunctions.

Cardiac atrophy after bed rest and spaceflight.

PubMed

Perhonen, M A; Franco, F; Lane, L D; Buckey, J C; Blomqvist, C G; Zerwekh, J E; Peshock, R M; Weatherall, P T; Levine, B D

2001-08-01

Cardiac muscle adapts well to changes in loading conditions. For example, left ventricular (LV) hypertrophy may be induced physiologically (via exercise training) or pathologically (via hypertension or valvular heart disease). If hypertension is treated, LV hypertrophy regresses, suggesting a sensitivity to LV work. However, whether physical inactivity in nonathletic populations causes adaptive changes in LV mass or even frank atrophy is not clear. We exposed previously sedentary men to 6 (n = 5) and 12 (n = 3) wk of horizontal bed rest. LV and right ventricular (RV) mass and end-diastolic volume were measured using cine magnetic resonance imaging (MRI) at 2, 6, and 12 wk of bed rest; five healthy men were also studied before and after at least 6 wk of routine daily activities as controls. In addition, four astronauts were exposed to the complete elimination of hydrostatic gradients during a spaceflight of 10 days. During bed rest, LV mass decreased by 8.0 +/- 2.2% (P = 0.005) after 6 wk with an additional atrophy of 7.6 +/- 2.3% in the subjects who remained in bed for 12 wk; there was no change in LV mass for the control subjects (153.0 +/- 12.2 vs. 153.4 +/- 12.1 g, P = 0.81). Mean wall thickness decreased (4 +/- 2.5%, P = 0.01) after 6 wk of bed rest associated with the decrease in LV mass, suggesting a physiological remodeling with respect to altered load. LV end-diastolic volume decreased by 14 +/- 1.7% (P = 0.002) after 2 wk of bed rest and changed minimally thereafter. After 6 wk of bed rest, RV free wall mass decreased by 10 +/- 2.7% (P = 0.06) and RV end-diastolic volume by 16 +/- 7.9% (P = 0.06). After spaceflight, LV mass decreased by 12 +/- 6.9% (P = 0.07). In conclusion, cardiac atrophy occurs during prolonged (6 wk) horizontal bed rest and may also occur after short-term spaceflight. We suggest that cardiac atrophy is due to a physiological adaptation to reduced myocardial load and work in real or simulated microgravity and demonstrates the plasticity

Cardiac atrophy after bed rest and spaceflight

NASA Technical Reports Server (NTRS)

Perhonen, M. A.; Franco, F.; Lane, L. D.; Buckey, J. C.; Blomqvist, C. G.; Zerwekh, J. E.; Peshock, R. M.; Weatherall, P. T.; Levine, B. D.

2001-01-01

Cardiac muscle adapts well to changes in loading conditions. For example, left ventricular (LV) hypertrophy may be induced physiologically (via exercise training) or pathologically (via hypertension or valvular heart disease). If hypertension is treated, LV hypertrophy regresses, suggesting a sensitivity to LV work. However, whether physical inactivity in nonathletic populations causes adaptive changes in LV mass or even frank atrophy is not clear. We exposed previously sedentary men to 6 (n = 5) and 12 (n = 3) wk of horizontal bed rest. LV and right ventricular (RV) mass and end-diastolic volume were measured using cine magnetic resonance imaging (MRI) at 2, 6, and 12 wk of bed rest; five healthy men were also studied before and after at least 6 wk of routine daily activities as controls. In addition, four astronauts were exposed to the complete elimination of hydrostatic gradients during a spaceflight of 10 days. During bed rest, LV mass decreased by 8.0 +/- 2.2% (P = 0.005) after 6 wk with an additional atrophy of 7.6 +/- 2.3% in the subjects who remained in bed for 12 wk; there was no change in LV mass for the control subjects (153.0 +/- 12.2 vs. 153.4 +/- 12.1 g, P = 0.81). Mean wall thickness decreased (4 +/- 2.5%, P = 0.01) after 6 wk of bed rest associated with the decrease in LV mass, suggesting a physiological remodeling with respect to altered load. LV end-diastolic volume decreased by 14 +/- 1.7% (P = 0.002) after 2 wk of bed rest and changed minimally thereafter. After 6 wk of bed rest, RV free wall mass decreased by 10 +/- 2.7% (P = 0.06) and RV end-diastolic volume by 16 +/- 7.9% (P = 0.06). After spaceflight, LV mass decreased by 12 +/- 6.9% (P = 0.07). In conclusion, cardiac atrophy occurs during prolonged (6 wk) horizontal bed rest and may also occur after short-term spaceflight. We suggest that cardiac atrophy is due to a physiological adaptation to reduced myocardial load and work in real or simulated microgravity and demonstrates the plasticity

Spaceflight Toxicology

NASA Technical Reports Server (NTRS)

Meyers, Valerie

2008-01-01

This viewgraph presentation provides a review of NASA Johnson Space Center's Toxicology program. The mission of this program is to protect crews from toxic exposures during spaceflight. The presentation reviews some of the health hazards. A toxicological hazard level chart is presented that reviews the rating of hazard level, irritancy, systemic effects and containability. The program also participates in the Lunar Airborne Dust Toxicity Advisory Group.

Adaptation of the Skeletal System during Long-duration Spaceflight

NASA Technical Reports Server (NTRS)

Sibonga, Jean D.; Cavanagh, Peter R.; Lang, Thomas F.; LeBlanc, Adrian D.; Schneider, Victor S.; Shackelford, Linda C.; Smith, Scott M.; Vico, Laurence

2008-01-01

exceeds spaceflight exposure but for which the restoration of whole bone strength remains an open issue and may involve structural alteration; and 4. Display risk factors for bone loss -- such as the negative calcium balance and down-regulated calcium-regulating hormones in response to bone atrophy -- that can be compounded by the constraints of conducting mission operations (inability to provide essential nutrients and vitamins). The full characterization of the skeletal response to mechanical unloading in space is not complete. In particular, countermeasures used to date have been inadequate and it is not yet known whether more appropriate countermeasures can prevent the changes in bone that have been found in previous flights, knowledge gaps related to the effects of prolonged (greater than or equal to 6 months) space exposure and to partial gravity environments are substantial, and longitudinal measurements on crew members after spaceflight are required to assess the full impact on skeletal recovery.

The Effect of Microgravity on the Smallest Space Travelers: Bacterial Physiology and Virulence on Earth and in Microgravity

NASA Technical Reports Server (NTRS)

Pyle, Barry; Vasques, Marilyn; Aquilina, Rudy (Technical Monitor)

2002-01-01

Since the first human flights outside of Earth's gravity, crew health and well-being have been major concerns. Exposure to microgravity during spaceflight is known to affect the human immune response, possibly making the crew members more vulnerable to infectious disease. In addition, biological experiments previously flown in space have shown that bacteria grow faster in microgravity than they do on Earth. The ability of certain antibiotics to control bacterial infections may also differ greatly in microgravity. It is therefore critical to understand how spaceflight and microgravity affect bacterial virulence, which is their ability to cause disease. By utilizing spaceflight hardware provided by the European Space Agency (ESA), Dr. Barry Pyle and his team at Montana State University, Bozeman, will be performing an experiment to study the effects of microgravity on the virulence of a common soil and water bacterium, Pseudomonas aeruginosa. Importantly, these bacteria have been detected in the water supplies of previous Space Shuttle flights. The experiment will examine the effects of microgravity exposure on bacterial growth and on the bacterium's ability to form a toxin called Exotoxin A. Another goal is to evaluate the effects of microgravity on the physiology of the bacteria by analyzing their ability to respire (produce energy), by studying the condition of the plasma membrane surrounding the cell, and by determining if specific enzymes remain active. Proteins produced by the bacteria will also be assayed to see if the normal functions of the bacteria are affected. In the context of human life support in spaceflight, the results of this experiment will offer guidance in providing the highest possible water quality for the Shuttle in order to limit the risk of infection to human occupants and to minimize water system and spacecraft deterioration.

Soluble metals in residual oil fly ash alter innate and adaptive pulmonary immune responses to bacterial infection in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, Jenny R.; Young, Shih-Houng; Castranova, Vincent

2007-06-15

The soluble metals of the pollutant, residual oil fly ash (ROFA), have been shown to alter pulmonary bacterial clearance in rats. The goal of this study was to determine the potential effects on both the innate and adaptive lung immune responses after bacterial infection in rats pre-exposed to the soluble metals in ROFA. Sprague-Dawley rats were intratracheally dosed (i.t.) at day 0 with ROFA (R-Total) (1.0 mg/100 g body weight), the soluble fraction of ROFA (R-Soluble), the soluble sample subject to a chelator (R-Chelex), or phosphate-buffered saline (Saline). On day 3, rats were administered an i.t. dose of 5 xmore » 10{sup 4} Listeria monocytogenes. On days 6, 8, and 10, bacterial pulmonary clearance was monitored and bronchoalveolar lavage (BAL) was performed on days 3 (pre-infection), 6, 8, and 10. A concentrated first fraction of lavage fluid was retained for analysis of lactate dehydrogenase and albumin to assess lung injury. BAL cell number, phenotype, and production of reactive oxygen (ROS) and nitrogen species (RNS) were assessed, and a variety of cytokines were measured in the BAL fluid. Rats pre-treated with R-Soluble showed elevated lung injury/cytotoxicity and increased cellular influx into the lungs. R-Soluble-treatment also altered ROS, RNS, and cytokine levels, and caused a degree of macrophage and T cell inhibition. These effects of R-Soluble result in increased pulmonary bacterial burden after infection. The results suggest that soluble metals in ROFA increase lung injury and inflammation, and alter both innate and adaptive pulmonary immune responses.« less

A model for plasma volume changes during short duration spaceflight

NASA Technical Reports Server (NTRS)

Davis, John E.

1989-01-01

It is well established that plasma volume decreases during spaceflight and simulated weightlessness (bedrest). The decrement in plasma volume is thought to contribute to the orthostatic intolerance that has been observed in some crew members following spaceflight. To date, no studies have evaluated the effectiveness of fluid countermeasures of varying osmolality in the restoration of plasma volume and orthostatic tolerance in a controlled study. The overall objectives of this project were to: (1) provide a model that would rapidly and safely produce a fluid loss comparable to that which occurs during short duration spaceflight; and (2) design a study that would determine the optimal drink solution to restore orthostatic tolerance and describe the mechanism(s) whereby orthostatic tolerance is restored. In summary, Lasix can be used as a way of simulating the plasma volume changes that occur during short duration spaceflight. The total loss of plasma is comparable to spaceflight. Lasix is fast acting, and has relatively few side effects. The present design for evaluating the optimal fluid countermeasures will have important implications in restoring orthostatic tolerance and function in the latter stages of spaceflight when it is essential for safe operation of the spacecraft.

Effects of spaceflight on the immunoglobulin repertoire of unimmunized C57BL/6 mice

NASA Astrophysics Data System (ADS)

Ward, Claire; Rettig, Trisha A.; Hlavacek, Savannah; Bye, Bailey A.; Pecaut, Michael J.; Chapes, Stephen K.

2018-02-01

Spaceflight has been shown to suppress the adaptive immune response, altering the distribution and function of lymphocyte populations. B lymphocytes express highly specific and highly diversified receptors, known as immunoglobulins (Ig), that directly bind and neutralize pathogens. Ig diversity is achieved through the enzymatic splicing of gene segments within the genomic DNA of each B cell in a host. The collection of Ig specificities within a host, or Ig repertoire, has been increasingly characterized in both basic research and clinical settings using high-throughput sequencing technology (HTS). We utilized HTS to test the hypothesis that spaceflight affects the B-cell repertoire. To test this hypothesis, we characterized the impact of spaceflight on the unimmunized Ig repertoire of C57BL/6 mice that were flown aboard the International Space Station (ISS) during the Rodent Research One validation flight in comparison to ground controls. Individual gene segment usage was similar between ground control and flight animals, however, gene segment combinations and the junctions in which gene segments combine was varied among animals within and between treatment groups. We also found that spontaneous somatic mutations in the IgH and Igκ gene loci were not increased. These data suggest that space flight did not affect the B cell repertoire of mice flown and housed on the ISS over a short period of time.

Engineering plants for spaceflight environments

NASA Technical Reports Server (NTRS)

Bugbee, B.

1999-01-01

The conversion efficiency of radiation into biomass and yield has steadily increased for centuries because of continued improvement in both plant genetics and environmental control. Considerable effort has gone into improving the environment for plant growth in space, but work has only begun to engineer plants for spaceflight. Genetic manipulation offers tremendous potential to improve our ability to study gravitational effects. Genetic manipulation will also be necessary to build an efficient regenerative life support system. We cannot fully characterize plant response to the spaceflight environment without understanding and manipulating their genetic composition. Identification and selection of the existing germplasm is the first step. There are thousands of cultivars of each of our major crop plants, each specifically adapted to a unique environment on our planet. Thousands of additional lines are held in national germplasm collections to maintain genetic diversity. Spaceflight imposes the need to tap this diversity. Existing lines need to be evaluated in the environment that is characteristic of closed-system spaceflight conditions. Many of the plant growth challenges we confront in space can be better solved through genetic change than by hardware engineering. Ten thousand years of plant breeding has demonstrated the value of matching genetics with the environment. For example, providing continuous light can increase plant growth in space, but this often induces calcium deficiencies because Ca is not supplied by guttation during a dark period. This deficiency cannot be eliminated through increased root-zone and foliar Ca applications. It can be solved, in wheat, through genetic selection of lines that do not have the deficiency. Subsequent comparison of lines with and without the Ca deficiency has also helped us understand the nature of the problem.

Experiment K-6-14. Hepatic function in rats after spaceflight

NASA Technical Reports Server (NTRS)

Merrill, A., Jr.; Hoel, M.; Wang, E.; Jones, D.; Hargrove, J.; Mullins, R.; Popova, I.

1990-01-01

To determine the possible biochemical consequences of prolonged weightlessness on liver function, tissue samples from rats that had flown aboard Cosmos 1887 were analyzed for hepatic protein, glycogen and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. Among the parameters measured, the major differences were elevations in the hepatic glycogen content and HMG-CoA reductase activities of the rats flown on Cosmos 1887, and a decrease in the amount of microsomal cytochrome P sub 450 and the activity of aniline hydroxylase, a cytochrome P sub 450-dependent enzyme. Decreases in these two indices of the microsomal mixed-function oxidase system indicated that spaceflight may compromise the ability of liver to metabolize drugs and toxins. The higher HMG-CoA reductase correlated with elevated levels of serum cholestrol. Other changes included somewhat higher blood glucose, creatinine, SGOT, and much greater alkaline phosphatase and BUN. These results generally support the earlier observation of changes in these parameters (Merrill et al., Am. J. Physiol. 252:R22-R226, 1987). The importance of these alterations in liver function is not known; however, they have the potential to complicate long-term spaceflight.

Human spaceflight in the UK: the cost of non-participation

NASA Astrophysics Data System (ADS)

Fong, Kevin

2004-06-01

Human space exploration is not considered a strategic priority in the United Kingdom at present. However the UK would benefit from participating in human spaceflight, for both scientific and social reasons. From the point of view of medical science there are many parallels between the physiology of spaceflight and terrestrial disease processes, and studies of the response of astronauts to long-duration spaceflight can therefore help in the development of therapeutic strategies on Earth. On the social side, human spaceflight is an attractive vehicle for stimulating the interest of young people in science and engineering, something that must be of value for an aspiring ‘knowledge-based’ economy.

Influence of spaceflight on the production of interleukin-3 and interleukin-6 by rat spleen and thymus cells

NASA Technical Reports Server (NTRS)

Miller, Edwin S.; Koebel, D. Anne; Sonnefeld, Gerald

1995-01-01

Six adult male Sprague-Dawley rats were flown on the 7-day US space shuttle mission STS-54. After flight, the spleen and thymus from each animal were assayed for the capacity to secrete the cytokines interleukin-3 (IL-3) and IL-6. Spleen and thymus cells were incubated for 48 h in the presence of 5 microgram/ml of concanavalin A or 2 microgram/ml of bacterial lipopolysaccharide to stimulate the production of IL-3 and IL-6. IL-3 activity was measured using the IL-3/colony-stimulating-factor-dependent cell line 32D. IL-6 activity was measured using the IL-6-dependent cell line 7TD1. Spleen and thymus cells harvested from flown rats secreted significantly higher titers of biologically active IL-3 compared with ground control rats. Spaceflight significantly enhanced IL-6 production by thymus, but not spleen, cells. The results of this study demonstrate that spaceflight can enhance the production of certain cytokines by cells of the immune system.

Spaceflight Enhances Cell Aggregation and Random Budding in Candida albicans

PubMed Central

Woolley, Christine M.; Barrila, Jennifer; Buchanan, Kent; McCracken, James; Inglis, Diane O.; Searles, Stephen C.; Nelman-Gonzalez, Mayra A.; Ott, C. Mark; Wilson, James W.; Pierson, Duane L.; Stefanyshyn-Piper, Heidemarie M.; Hyman, Linda E.; Nickerson, Cheryl A.

2013-01-01

This study presents the first global transcriptional profiling and phenotypic characterization of the major human opportunistic fungal pathogen, Candida albicans, grown in spaceflight conditions. Microarray analysis revealed that C. albicans subjected to short-term spaceflight culture differentially regulated 452 genes compared to synchronous ground controls, which represented 8.3% of the analyzed ORFs. Spaceflight-cultured C. albicans–induced genes involved in cell aggregation (similar to flocculation), which was validated by microscopic and flow cytometry analysis. We also observed enhanced random budding of spaceflight-cultured cells as opposed to bipolar budding patterns for ground samples, in accordance with the gene expression data. Furthermore, genes involved in antifungal agent and stress resistance were differentially regulated in spaceflight, including induction of ABC transporters and members of the major facilitator family, downregulation of ergosterol-encoding genes, and upregulation of genes involved in oxidative stress resistance. Finally, downregulation of genes involved in actin cytoskeleton was observed. Interestingly, the transcriptional regulator Cap1 and over 30% of the Cap1 regulon was differentially expressed in spaceflight-cultured C. albicans. A potential role for Cap1 in the spaceflight response of C. albicans is suggested, as this regulator is involved in random budding, cell aggregation, and oxidative stress resistance; all related to observed spaceflight-associated changes of C. albicans. While culture of C. albicans in microgravity potentiates a global change in gene expression that could induce a virulence-related phenotype, no increased virulence in a murine intraperitoneal (i.p.) infection model was observed under the conditions of this study. Collectively, our data represent an important basis for the assessment of the risk that commensal flora could play during human spaceflight missions. Furthermore, since the low fluid

Comparison of the Physiology of the Spaceflight and Hindlimb Suspended Rat

NASA Technical Reports Server (NTRS)

Grindeland, R. E.; Booth, F. W.

1994-01-01

The suspended rat has been used extensively as a simulation of the spaceflight animal. In suspension, hindlimbs are unloaded from the acceleration of gravity, much as they are in spaceflight. Comparisons of data from spaceflight (microgravity) and suspended (1G) rats have suggested that suspension my be an appropriate model, but no direct comparisons had been made between the spaceflight and suspended rat. Cosmos 2044 afforded the first opportunity to directly compare the effects of hindlimb suspension (HS) and spaceflight (SF) on a broad range of physiological and histological parameters. This paper reports on the comparison of skelton, skeletal muscle, heart, neural, pulmonary, kidney, liver, intestine, blood plasma, immune function, red blood cells, and endocrine and reproductive functions and systems.

Modification of reproductive development in Arabidopsis thaliana under spaceflight conditions

NASA Technical Reports Server (NTRS)

Kuang, A.; Musgrave, M. E.; Matthews, S. W.

1996-01-01

Reproductive development in Arabidopsis thaliana (L.) Heynh. cv. Columbia plants was investigated under spaceflight conditions on shuttle mission STS-51. Plants launched just prior to initiation of the reproductive phase developed flowers and siliques during the 10-d flight. Approximately 500 flowers were produced in total by the 12 plants in both the ground control and spaceflight material, and there was no significant difference in the number of flowers in each size class. The flower buds and siliques of the spaceflight plants were not morphologically different from the ground controls. Pollen viability tests immediately post-flight using fluorescein diacetate indicated that about 35% of the pollen was viable in the spaceflight material. Light-microscopy observations on this material showed that the female gametophytes also had developed normally to maturity. However, siliques from the spaceflight plants contained empty, shrunken ovules, and no evidence of pollen transfer to stigmatic papillae was found by light microscopy immediately post-flight or by scanning electron microscopy on fixed material. Short stamen length and indehiscent anthers were observed in the spaceflight material, and a film-like substance inside the anther that connected to the tapetum appeared to restrict the release of pollen from the anthers. These observations indicate that given appropriate growing conditions, early reproductive development in A. thaliana can occur normally under spaceflight conditions. On STS-51, reproductive development aborted due to obstacles in pollination or fertilization.

Vitamin K status in spaceflight and ground-based models of spaceflight

USDA-ARS?s Scientific Manuscript database

Bone loss is a well-documented change during and after long-duration spaceflight. Many types of countermeasures to bone loss have been proposed, including vitamin K supplementation. The objective of this series of studies was to measure change in vitamin K status in response to microgravity under a ...

Sleep-Wake Actigraphy and Light Exposure During Spaceflight-Long

NASA Technical Reports Server (NTRS)

Czeisler, Charles A.; Barger, Laura K.; Wright, Kenneth P., Jr.; Ronda, Joseph

2009-01-01

Sleep-Wake Actigraphy and Light Exposure During Spaceflight-Long (Sleep-Long) will examine the effects of spaceflight and ambient light exposure on the sleep-wake cycles of the crew members during long-duration stays on the space station.

Human Spaceflight Safety Hearing

NASA Image and Video Library

2009-12-02

U.S. Rep. Pete Olson, R-Texas, speaks during a hearing before the House Subcommitte on Space and Aeronautics regarding Safety of Human Spaceflight on Capitol Hill, Wednesday, Dec. 2, 2009, in Washington. Photo Credit: (NASA/Bill Ingalls)

Effect of spaceflight on natural killer cell activity

NASA Technical Reports Server (NTRS)

Rykova, Marina P.; Sonnenfeld, Gerald; Lesniak, A. T.; Taylor, Gerald R.; Meshkov, Dimitrii O.; Mandel, Adrian D.; Medvedev, Andrei E.; Berry, Wallace D.; Fuchs, Boris B.; Konstantinova, Irina V.

1992-01-01

The effects of spaceflight on immune cell function were determined in rats flown on Cosmos 2044. Control groups included vivarium, synchronous, and antiorthostatically suspended rats. The ability of natural killer cells to lyse two different target cell lines was determined. Spleen and bone marrow cells obtained from flight rats showed significantly inhibited cytotoxicity for YAC-1 target cells compared with cells from synchronous control rats. This could have been due to exposure of the rats to microgravity. Antiorthostatic suspension did not affect the level of cytotoxicity from spleen cells of suspended rats for YAC-1 cells. On the other hand, cells from rats flown in space showed no significant differences from vivarium and synchronous control rats in cytotoxicity for K-562 target cells. Binding of natural killer cells to K-562 target cells was unaffected by spaceflight. Antiorthostatic suspension resulted in higher levels of cytotoxicity from spleen cells for Cr-51-labeled K-562 cells. The results indicate differential effects of spaceflight on function of natural killer cells. This shows that spaceflight has selective effects on the immune response.

Effect of spaceflight on rat hepatocytes - A morphometric study

NASA Technical Reports Server (NTRS)

Racine, Richard N.; Cormier, Susan M.

1992-01-01

Hepatic tissue from flight, synchronous, vivarium, and tail-suspended rats was examined by light microscopy and computer-assisted image analysis. Glycogen levels in flight rats were found to be significantly elevated over those in controls. Lipid was also higher but not significantly different. Hepatocytes appeared larger in flight animals because of area attributed to increased glycogen. Sinusoids were less prominent in flight animals than in controls. The total Kupffer cell population appeared to be reduced in flight animals and may represent changes in defensive capacity of the liver. Alterations in the storage of glycogen and number of Kupffer cells suggest an important effect of spacefligtht on the function of the liver that may have important implications for long-term spaceflight.

Human Spaceflight Safety Hearing

NASA Image and Video Library

2009-12-02

Dr. Joseph R. Fragola, Vice President, Valador, Inc., testifies during a hearing before the House Subcommitte on Space and Aeronautics regarding Safety of Human Spaceflight on Capitol Hill, Wednesday, Dec. 2, 2009, in Washington. Photo Credit: (NASA/Bill Ingalls)

Comparison of Echocardiographic Measurements Before and After Short and Long Duration Spaceflight

NASA Technical Reports Server (NTRS)

Fritsch-Yelle, Janice M.; South, Donna A.; Wood, Margie L.; Bungo, Michael W.

2000-01-01

Previous echocardiography studies in astronauts before and after short duration (4 - 17 days) missions have demonstrated a decrease in resting left ventricular (LV) stroke volume (SV), but maintained ejection fraction (EF) and cardiac output. Similar studies before and after long duration (129 - 144 days) spaceflight have been rare and their overall results equivocal. The purpose of this work was to compare the echocardiographic measurements (M-mode, 2-D and Doppler) from short duration (n = 13) and long duration (n = 4) crewmembers. Compared to short duration astronauts, long duration crewmembers had a significantly greater percent decrease in EF (+6+/-0.02 vs.-10.5+/-0.03, p = 0.005) and percent fractional shortening (+7+/-0.03 vs. -11+/-0.07, p = 0.0 15), and an increase in LV end systolic volume (-12+/-0.06 vs. +39+/-0.24, p = 0.011). These data suggest a reduction in cardiac function that relates to mission duration. As the changes in blood pressure and circulating blood volume (9% - 12%) are reported to be similar after short and long duration flights, the drop in EF after longer spaceflights is likely due to a decrease in cardiac function rather than altered blood volume.

Effects of spaceflight on polysaccharides of Saccharomyces cerevisiae cell wall.

PubMed

Liu, Hong-Zhi; Wang, Qiang; Liu, Xiao-Yong; Tan, Sze-Sze

2008-12-01

Freeze-dried samples of four Saccharomyces cerevisiae strains, namely, FL01, FL03, 2.0016, and 2.1424, were subjected to spaceflight. After the satellite's landing on Earth, the samples were recovered and changes in yeast cell wall were analyzed. Spaceflight strains of all S. cerevisiae strains showed significant changes in cell wall thickness (P < 0.05). One mutant of S. cerevisiae 2.0016 with increased biomass, cell wall thickness, and cell wall glucan was isolated (P < 0.05). The spaceflight mutant of S. cerevisiae 2.0016 showed 46.7%, 62.6%, and 146.0% increment in biomass, cell wall thickness and beta-glucan content, respectively, when compared to the ground strain. Moreover, growth curve analysis showed spaceflight S. cerevisiae 2.0016 had a faster growth rate, shorter lag phase periods, higher final biomass, and higher content of beta-glucan. Genetic stability analysis showed that prolonged subculturing of spaceflight strain S. cerevisiae 2.0016 did not lead to the appearance of variants, indicating that the genetic stability of S. cerevisiae 2.0016 mutant could be sufficient for its exploitation of beta-glucan production.

Regeneration of eye tissues is modulated by altered levels of gravity at 1g, 2g, and in microgravity during spaceflight

NASA Astrophysics Data System (ADS)

Grigoryan, Eleonora; Almeida, Eduardo; Mitashov, Victor

The pursuit of human space exploration requires detailed knowledge of microgravity-related changes in fundamental biological processes, and their effects on health. Normal regeneration of organs and tissues is one such fundamental process that allows maintenance of vitality and function of living organisms. Animal models of tissue regeneration include the newt (Pleurodeles waltl, Urodela) eye, which has been extensively used by our team in Russian Bion and Foton microgravity experiments since 1985, and in recent NASA 2.5 meter diameter centrifuge hypergravity experiments. In total, these experiments allow us to draw several broad conclusions: Newt lens regeneration is significantly altered in microgravity and hypergravity relative to 1g controls. Lenses formed in microgravity are larger and more developed than those regenerated in 1g controls; Microgravity alterations of lens regeneration can persist after spaceflight, and continue to affect repeated removal and regeneration of the lens after return to 1g; Microgravity increases the numbers of early stage regenerative proliferating BrdU-labeled cells in dorsal iris progenitors and in the lens regenerate. Regeneration under hypergravity conditions at 2g inhibits lens regeneration, and often causes retinal detachment. Molecular mechanisms regulating lens regeneration rate include FGF2 signaling, (a key pathway for eye tissue development and regeneration), and an expression of stress-related proteins - HSPs. In conclusion, regeneration of lens and other eye tissues in the newt is sensitive to, and regulated by the level of gravity mechanotransduction and developmental signaling pathways, with microgravity favoring stem cell progenitor proliferation, and gravity at 1g promoting terminal differentiation, while hypergravity at 2g often causes damage of delicate regenerating tissues.

Bacterial lipopolysaccharide-induced systemic inflammation alters perfusion of white matter-rich regions without altering flow in brain-irrigating arteries: Relationship to blood-brain barrier breakdown?

PubMed

Dhaya, Ibtihel; Griton, Marion; Raffard, Gérard; Amri, Mohamed; Hiba, Bassem; Konsman, Jan Pieter

2018-01-15

To better understand brain dysfunction during sepsis, cerebral arterial blood flow was assessed with Phase Contrast Magnetic Resonance Imaging, perfusion with Arterial Spin Labeling and structure with diffusion-weighted Magnetic Resonance Imaging in rats after intraperitoneal administration of bacterial lipopolysaccharides. Although cerebral arterial flow was not altered, perfusion of the corpus callosum region and diffusion parallel to its fibers were higher after lipopolysaccharide administration as compared to saline injection. In parallel, lipopolysaccharide induced perivascular immunoglobulin-immunoreactivity in white matter. These findings indicate that systemic inflammation can result in increased perfusion, blood-brain barrier breakdown and altered water diffusion in white matter. Copyright © 2017 Elsevier B.V. All rights reserved.

Cellular immunity and lymphokine production during spaceflights

NASA Technical Reports Server (NTRS)

Konstantinova, I. V.; Sonnenfeld, G.; Lesniak, A. T.; Shaffar, L.; Mandel, A.; Rykova, M. P.; Antropova, E. N.; Ferrua, B.

1991-01-01

Results are presented on changes in cellular immunity and in the production of lymphokine in spacecrews during spaceflights. Measurements were carried out on blood samples collected from 50 cosmonauts before and after spaceflights of different duration, on board Salyut-6, Salyut-7, or Mir. Additional data were obtained from rats flown on board the Cosmos-1667 and Cosmos-1887 biosatellites. The parameters measured included the PHA responsiveness of T lymphocytes, the activity of T-helper cells and of nonspecific T suppressors, the activity of the so-called natural killer lymphocytes, the production of gamma-interferon, and the cell-surface markers. Results showed that the frequency and the extent of changes in the immunologic resistance of subjects depended on the duration of the flight. However, even after the most prolonged (365 days) spaceflight, the changes observed were mostly of a functional character with subsequent rapid return to normal.

NASA 14 Day Undersea Missions: A Short-Duration Spaceflight Analog for Immune System Dysregulation

NASA Technical Reports Server (NTRS)

Crucian, B. E.; Stowe, R. P.; Mehta, S. K.; Quiriarte, H.; Pierson, D. L.; Sams, C. F.

2010-01-01

BACKGROUND Spaceflight-associated immune dysregulation (SAID) occurs during spaceflight and may represent specific clinical risks for exploration-class missions. An appropriate ground analog for spaceflight-associated immune dysregulation would offer a platform for ground-evaluation of various potential countermeasures. This study evaluated the NASA Undersea Mission Operations ( NEEMO ), consisting of 14 day undersea deployment at the Aquarius station, as an analog for SAID. Sixteen Aquanauts from missions NEEMO-12, 13 and 14 participated in the study. RESULTS Mid-mission alterations leukocyte distribution occurred, including granulocytosis and elevations in central-memory CD8+ T-cells. General T cell function was reduced during NEEMO missions in roughly 50% of subjects. Secreted cytokines profiles were evaluated following whole blood stimulation with CD3/CD28 (T cells) or LPS (monocytes). T cell production of IFNg, IL-5, IL-10, IL-2, TNFa and IL-6 were all reduced before and during the mission. Conversely, monocyte production of TNFa, IL-10, IL-6, IL-1b and IL-8 were elevated during mission, moreso at the MD-14 timepoint. Antibodies to Epstein-Barr virus (EBV) viral capsid antigen and early antigen were increased in approximately 40% of the subjects. Changes in EBV tetramer-positive CD8+ T-cells exhibited a variable pattern. Antibodies against Cytomegalovirus (CMV) were marginally increased during the mission. Herpesvirus reactivation was determined by PCR. EBV viral load was generally elevated at L-6. Higher levels of salivary EBV were found during the NEEMO mission than before and after as well as than the healthy controls. No VZV or CMV was found in any pre, during and after NEEMO mission or control samples. Plasma cortisol was elevated at L-6. CONCLUSION Unfortunately, L-6 may be too near to mission start to be an appropriate baseline measurement. The general immune changes in leukocyte distribution, T cell function, cytokine production, virus specific

Effects of spaceflight on the immunoglobulin repertoire of unimmunized C57BL/6 mice.

PubMed

Ward, Claire; Rettig, Trisha A; Hlavacek, Savannah; Bye, Bailey A; Pecaut, Michael J; Chapes, Stephen K

2018-02-01

Spaceflight has been shown to suppress the adaptive immune response, altering the distribution and function of lymphocyte populations. B lymphocytes express highly specific and highly diversified receptors, known as immunoglobulins (Ig), that directly bind and neutralize pathogens. Ig diversity is achieved through the enzymatic splicing of gene segments within the genomic DNA of each B cell in a host. The collection of Ig specificities within a host, or Ig repertoire, has been increasingly characterized in both basic research and clinical settings using high-throughput sequencing technology (HTS). We utilized HTS to test the hypothesis that spaceflight affects the B-cell repertoire. To test this hypothesis, we characterized the impact of spaceflight on the unimmunized Ig repertoire of C57BL/6 mice that were flown aboard the International Space Station (ISS) during the Rodent Research One validation flight in comparison to ground controls. Individual gene segment usage was similar between ground control and flight animals, however, gene segment combinations and the junctions in which gene segments combine was varied among animals within and between treatment groups. We also found that spontaneous somatic mutations in the IgH and Igκ gene loci were not increased. These data suggest that space flight did not affect the B cell repertoire of mice flown and housed on the ISS over a short period of time. Copyright © 2017 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Effect of spaceflight on the circadian rhythm, lifespan and gene expression of Drosophila melanogaster.

PubMed

Ma, Lingling; Ma, Jun; Xu, Kanyan

2015-01-01

Space travelers are reported to experience circadian rhythm disruption during spaceflight. However, how the space environment affects circadian rhythm is yet to be determined. The major focus of this study was to investigate the effect of spaceflight on the Drosophila circadian clock at both the behavioral and molecular level. We used China's Shenzhou-9 spaceship to carry Drosophila. After 13 days of spaceflight, behavior tests showed that the flies maintained normal locomotor activity rhythm and sleep pattern. The expression level and rhythm of major clock genes were also unaffected. However, expression profiling showed differentially regulated output genes of the circadian clock system between space flown and control flies, suggesting that spaceflight affected the circadian output pathway. We also investigated other physiological effects of spaceflight such as lipid metabolism and lifespan, and searched genes significantly affected by spaceflight using microarray analysis. These results provide new information on the effects of spaceflight on circadian rhythm, lipid metabolism and lifespan. Furthermore, we showed that studying the effect of spaceflight on gene expression using samples collected at different Zeitgeber time could obtain different results, suggesting the importance of appropriate sampling procedures in studies on the effects of spaceflight.

Effect of Spaceflight on the Circadian Rhythm, Lifespan and Gene Expression of Drosophila melanogaster

PubMed Central

Xu, Kanyan

2015-01-01

Space travelers are reported to experience circadian rhythm disruption during spaceflight. However, how the space environment affects circadian rhythm is yet to be determined. The major focus of this study was to investigate the effect of spaceflight on the Drosophila circadian clock at both the behavioral and molecular level. We used China’s Shenzhou-9 spaceship to carry Drosophila. After 13 days of spaceflight, behavior tests showed that the flies maintained normal locomotor activity rhythm and sleep pattern. The expression level and rhythm of major clock genes were also unaffected. However, expression profiling showed differentially regulated output genes of the circadian clock system between space flown and control flies, suggesting that spaceflight affected the circadian output pathway. We also investigated other physiological effects of spaceflight such as lipid metabolism and lifespan, and searched genes significantly affected by spaceflight using microarray analysis. These results provide new information on the effects of spaceflight on circadian rhythm, lipid metabolism and lifespan. Furthermore, we showed that studying the effect of spaceflight on gene expression using samples collected at different Zeitgeber time could obtain different results, suggesting the importance of appropriate sampling procedures in studies on the effects of spaceflight. PMID:25798821

Structure of potato tubers formed during spaceflight

NASA Technical Reports Server (NTRS)

Croxdale, J.; Cook, M.; Tibbitts, T. W.; Brown, C. S.; Wheeler, R. M.

1997-01-01

Potato (Solanum tuberosum L. cv. Norland) explants, consisting of a leaf, axillary bud, and small stem segment, were used as a model system to study the influence of spaceflight on the formation of sessile tubers from axillary buds. The explants were flown on the space shuttle Columbia (STS-73, 20 October to 5 November 1995) in the ASTROCULTURE (TM) flight package, which provided a controlled environment for plant growth. Light and scanning electron microscopy were used to compare the precisely ordered tissues of tubers formed on Earth with those formed during spaceflight. The structure of tubers produced during spaceflight was similar to that of tubers produced in a control experiment. The size and shape of tubers, the geometry of tuber tissues, and the distribution of starch grains and proteinaceous crystals were comparable in tubers formed in both environments. The shape, surface texture, and size range of starch grains from both environments were similar, but a greater percentage of smaller starch grains formed in spaceflight than on Earth. Since explant leaves must be of given developmental age before tubers form, instructions regarding the regular shape and ordered tissue geometry of tubers may have been provided in the presence of gravity. Regardless of when the signalling occurred, gravity was not required to produce a tuber of typical structure.

Securing Safety - Spaceflight Standards for the Mass Market

NASA Astrophysics Data System (ADS)

Goh, G.

The projected total revenue of the space tourism industry is expected to exceed USD $1 billion by 2021. The vast economic potential of space tourism has fuelled ambitious plans for commercial orbital and suborbital flights, in addition to longer- duration spaceflights on board the International Space Station (ISS) and other planned orbiting habitats. International and national legal frameworks are challenged to provide regulations to ensure minimum standards of spaceflight safety for a high risk activity that aims to enter the mainstream tourism market. Thrown into the mix are various considerations of the number of spaceflight participants per flight, the economic viability of stringent safety standards, the plethora of possible flight vehicles and the compensation mechanism in case of violations of safety regulations. This paper surveys the legal challenges in the regulation of safety in commercial manned spaceflight, including issues of jurisdiction, authorization, licensing and liability. Drawing on analogous developments in other fields of law related to international carriage, a safety regulation framework with minimum international standards is proposed. This proposed framework considers both accident avoidance and emergency response in light of international legal, policy and economic perspectives.

Deoxygenation alters bacterial diversity and community composition in the ocean's largest oxygen minimum zone.

PubMed

Beman, J Michael; Carolan, Molly T

2013-01-01

Oceanic oxygen minimum zones (OMZs) have a central role in biogeochemical cycles and are expanding as a consequence of climate change, yet how deoxygenation will affect the microbial communities that control these cycles is unclear. Here we sample across dissolved oxygen gradients in the oceans' largest OMZ and show that bacterial richness displays a unimodal pattern with decreasing dissolved oxygen, reaching maximum values on the edge of the OMZ and decreasing within it. Rare groups on the OMZ margin are abundant at lower dissolved oxygen concentrations, including sulphur-cycling Chromatiales, for which 16S rRNA was amplified from extracted RNA. Microbial species distribution models accurately replicate community patterns based on multivariate environmental data, demonstrate likely changes in distributions and diversity in the eastern tropical North Pacific Ocean, and highlight the sensitivity of key bacterial groups to deoxygenation. Through these mechanisms, OMZ expansion may alter microbial composition, competition, diversity and function, all of which have implications for biogeochemical cycling in OMZs.

Spaceflight and growth effects on muscle fibers in the rhesus monkey

NASA Technical Reports Server (NTRS)

Bodine-Fowler, Sue C.; Roy, Roland R.; Rudolph, William; Haque, Naz; Kozlovskaia, Inessa B.; Edgerton, V. R.

1992-01-01

The effect of a 14-day spaceflight onboard Cosmos 2044 on selected morphological and metabolic properties of single muscle fibers was investigated in a nonhuman primate, Macaca mulatta. It is concluded that the 14-day spaceflight had little impact on fiber size in the soleus (S) and medial gastrocnemius (MG) muscles, whereas it appeared to be a slight decrease in sized in the tibialis anterior (TA). The mean fiber size in the postflight biopsies increased relative to preflight values. The mean fiber succinate dehydrogenase activity was found to decrease in the MG, whereas there was no apparent effect of spaceflight on the s and ta muscles. The differences in response of the S, MG, and TA to spaceflight in monkeys vs rats may be related to a species responsiveness to spaceflight, the manner in which the animals were restrained, and/or the possibility that the ankle musculature was able to function against a load while in space.

Human Spaceflight and American Society: The Record So Far

NASA Technical Reports Server (NTRS)

Murray, Charles

2005-01-01

This paper presents a look at the historical Apollo Program and it's comparisons to NASA's human spaceflight program today. The author gives three examples of how audacity began with the Apollo Program and explains how human spaceflight must continue with this audacity to do new things and take on large missions.

Brain Activations for Vestibular Stimulation and Dual Tasking Change with Spaceflight

NASA Technical Reports Server (NTRS)

Yuan, Peng; Koppelmans, Vincent; Reuter-Lorenz, Patricia; De Dios, Yiri; Gadd, Nichole; Wood, Scott; Riascos, Roy; Kofman, Igor; Bloomberg, Jacob; Mulavara, Ajitkumar;

The effectiveness of RNAi in Caenorhabditis elegans is maintained during spaceflight.

PubMed

Etheridge, Timothy; Nemoto, Kanako; Hashizume, Toko; Mori, Chihiro; Sugimoto, Tomoko; Suzuki, Hiromi; Fukui, Keiji; Yamazaki, Takashi; Higashibata, Akira; Szewczyk, Nathaniel J; Higashitani, Atsushi

2011-01-01

Overcoming spaceflight-induced (patho)physiologic adaptations is a major challenge preventing long-term deep space exploration. RNA interference (RNAi) has emerged as a promising therapeutic for combating diseases on Earth; however the efficacy of RNAi in space is currently unknown. Caenorhabditis elegans were prepared in liquid media on Earth using standard techniques and treated acutely with RNAi or a vector control upon arrival in Low Earth Orbit. After culturing during 4 and 8 d spaceflight, experiments were stopped by freezing at -80°C until analysis by mRNA and microRNA array chips, microscopy and Western blot on return to Earth. Ground controls (GC) on Earth were simultaneously grown under identical conditions. After 8 d spaceflight, mRNA expression levels of components of the RNAi machinery were not different from that in GC (e.g., Dicer, Argonaute, Piwi; P>0.05). The expression of 228 microRNAs, of the 232 analysed, were also unaffected during 4 and 8 d spaceflight (P>0.05). In spaceflight, RNAi against green fluorescent protein (gfp) reduced chromosomal gfp expression in gonad tissue, which was not different from GC. RNAi against rbx-1 also induced abnormal chromosome segregation in the gonad during spaceflight as on Earth. Finally, culture in RNAi against lysosomal cathepsins prevented degradation of the muscle-specific α-actin protein in both spaceflight and GC conditions. Treatment with RNAi works as effectively in the space environment as on Earth within multiple tissues, suggesting RNAi may provide an effective tool for combating spaceflight-induced pathologies aboard future long-duration space missions. Furthermore, this is the first demonstration that RNAi can be utilised to block muscle protein degradation, both on Earth and in space.

The Effectiveness of RNAi in Caenorhabditis elegans Is Maintained during Spaceflight

PubMed Central

Hashizume, Toko; Mori, Chihiro; Sugimoto, Tomoko; Suzuki, Hiromi; Fukui, Keiji; Yamazaki, Takashi; Higashibata, Akira; Szewczyk, Nathaniel J.; Higashitani, Atsushi

2011-01-01

Background Overcoming spaceflight-induced (patho)physiologic adaptations is a major challenge preventing long-term deep space exploration. RNA interference (RNAi) has emerged as a promising therapeutic for combating diseases on Earth; however the efficacy of RNAi in space is currently unknown. Methods Caenorhabditis elegans were prepared in liquid media on Earth using standard techniques and treated acutely with RNAi or a vector control upon arrival in Low Earth Orbit. After culturing during 4 and 8 d spaceflight, experiments were stopped by freezing at −80°C until analysis by mRNA and microRNA array chips, microscopy and Western blot on return to Earth. Ground controls (GC) on Earth were simultaneously grown under identical conditions. Results After 8 d spaceflight, mRNA expression levels of components of the RNAi machinery were not different from that in GC (e.g., Dicer, Argonaute, Piwi; P>0.05). The expression of 228 microRNAs, of the 232 analysed, were also unaffected during 4 and 8 d spaceflight (P>0.05). In spaceflight, RNAi against green fluorescent protein (gfp) reduced chromosomal gfp expression in gonad tissue, which was not different from GC. RNAi against rbx-1 also induced abnormal chromosome segregation in the gonad during spaceflight as on Earth. Finally, culture in RNAi against lysosomal cathepsins prevented degradation of the muscle-specific α-actin protein in both spaceflight and GC conditions. Conclusions Treatment with RNAi works as effectively in the space environment as on Earth within multiple tissues, suggesting RNAi may provide an effective tool for combating spaceflight-induced pathologies aboard future long-duration space missions. Furthermore, this is the first demonstration that RNAi can be utilised to block muscle protein degradation, both on Earth and in space. PMID:21673804

Effects of spaceflight and simulated weightlessness on longitudinal bone growth

NASA Technical Reports Server (NTRS)

Sibonga, J. D.; Zhang, M.; Evans, G. L.; Westerlind, K. C.; Cavolina, J. M.; Morey-Holton, E.; Turner, R. T.

2000-01-01

Indirect measurements have suggested that spaceflight impairs bone elongation in rats. To test this possibility, our laboratory measured, by the fluorochrome labeling technique, bone elongation that occurred during a spaceflight experiment. The longitudinal growth rate (LGR) in the tibia of rats in spaceflight experiments (Physiological Space Experiments 1, 3, and 4 and Physiological-Anatomical Rodent Experiment 3) and in two models of skeletal unloading (hind-limb elevation and unilateral sciatic neurotomy) were calculated. The effects of an 11 day spaceflight on gene expression of cartilage matrix proteins in rat growth plates were also determined by northern analysis and are reported for the first time in this study. Measurements of longitudinal growth indicate that skeletal unloading generally did not affect LGR, regardless of age, strain, gender, duration of unloading, or method of unloading. There was, however, one exception with 34% suppression in LGR detected in slow-growing, ovariectomized rats skeletally unloaded for 8 days by hind-limb elevation. This detection of reduced LGR by hind-limb elevation is consistent with changes in steady-state mRNA levels for type II collagen (-33%) and for aggrecan (-53%) that were detected in rats unloaded by an 11 day spaceflight. The changes detected in gene expression raise concern that spaceflight may result in changes in the composition of extracellular matrix, which could have a negative impact on conversion of growth-plate cartilage into normal cancellous bone by endochondral ossification.

Spaceflight and the Mouse Eye: Results from Experiments on Shuttle Missions STS-133 and STS-135

NASA Technical Reports Server (NTRS)

Zanello, Susana B.; Theriot, Corey A.; Ponce, Claudia Prospero; Chevez-Barrios, Patricia

2013-01-01

Vision alterations associated with globe flattening, chorodial folds and papilledema, shown in some crew members returning from long duration missions. Hypothesis: Ocular neuroanatomical changes observed in the VIIP syndrome are accompanied by retinal changes at the molecular and cellular level that may affect retinal health and physiology. Objective: Investigate evidence of ocular (retinal) changes associated with spaceflight: (1) histological markers of cellular death and damage (2) molecular markers of oxidative stress (3) gene expression markers of stress

Mechanical Unloading of Mouse Bone in Microgravity Significantly Alters Cell Cycle Gene Set Expression

NASA Astrophysics Data System (ADS)

Blaber, Elizabeth; Dvorochkin, Natalya; Almeida, Eduardo; Kaplan, Warren; Burns, Brnedan

2012-07-01

Spaceflight factors, including microgravity and space radiation, have many detrimental short-term effects on human physiology, including muscle and bone degradation, and immune system dysfunction. The long-term progression of these physiological effects is still poorly understood, and a serious concern for long duration spaceflight missions. We hypothesized that some of the degenerative effects of spaceflight may be caused in part by an inability of stem cells to proliferate and differentiate normally resulting in an impairment of tissue regenerative processes. Furthermore, we hypothesized that long-term bone tissue degeneration in space may be mediated by activation of the p53 signaling network resulting in cell cycle arrest and/or apoptosis in osteoprogenitors. In our analyses we found that spaceflight caused significant bone loss in the weight-bearing bones of mice with a 6.3% reduction in bone volume and 11.9% decrease in bone thickness associated with increased osteoclastic activity. Along with this rapid bone loss we also observed alterations in the cell cycle characterized by an increase in the Cdkn1a/p21 cell cycle arrest molecule independent of Trp53. Overexpression of Cdkn1a/p21 was localized to osteoblasts lining the periosteal surface of the femur and chondrocytes in the head of the femur, suggesting an inhibition of proliferation in two key regenerative cell types of the femur in response to spaceflight. Additionally we found overexpression of several matrix degradation molecules including MMP-1a, 3 and 10, of which MMP-10 was localized to osteocytes within the shaft of the femur. This, in conjunction with 40 nm resolution synchrotron nano-Computed Tomography (nano-CT) observations of an increase in osteocyte lacunae cross-sectional area, perimeter and a decrease in circularity indicates a potential role for osteocytic osteolysis in the observed bone degeneration in spaceflight. To further investigate the genetic response of bone to mechanical

Sleep-Wake Actigraphy and Light Exposure During Spaceflight - Short

NASA Technical Reports Server (NTRS)

Czeisler, Charles A.; Wright, Kenneth P., Jr.; Ronda, Joseph

2009-01-01

Sleep-Wake Actigraphy and Light Exposure During Spaceflight - Short (Sleep-Short) will examine the effects of spaceflight on the sleep of the astronauts during space shuttle missions. Advancing state-of-the-art technology for monitoring, diagnosing and assessing treatment of sleep patterns is vital to treating insomnia on Earth and in space.

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto, with Instrumentation Technology Associates, Inc., works on an experiment found during the search for Columbia debris. Mike Casasanto, also with ITA, looks on. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-06

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto, with Instrumentation Technology Associates, Inc., works on an experiment found during the search for Columbia debris. Mike Casasanto, also with ITA, looks on. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

[Malfunction simulation by spaceflight training simulator].

PubMed

Chang, Tian-chun; Zhang, Lian-hua; Xue, Liang; Lian, Shun-guo

2005-04-01

To implement malfunction simulation in spaceflight training simulator. The principle of malfunction simulation was defined according to spacecraft malfunction predict and its countermeasures. The malfunction patterns were classified, and malfunction type was confirmed. A malfunction simulation model was established, and the malfunction simulation was realized by math simulation. According to the requirement of astronaut training, a spacecraft subsystem malfunction simulation model was established and realized, such as environment control and life support, GNC, push, power supply, heat control, data management, measure control and communication, structure and so on. The malfunction simulation function implemented in the spaceflight training simulator satisfied the requirements for astronaut training.

Printed Electronic Devices in Human Spaceflight

NASA Technical Reports Server (NTRS)

Bacon, John B.

2004-01-01

The space environment requires robust sensing, control, and automation, whether in support of human spaceflight or of robotic exploration. Spaceflight embodies the known extremes of temperature, radiation, shock, vibration, and static loads, and demands high reliability at the lowest possible mass. Because printed electronic circuits fulfill all these requirements, printed circuit technology and the exploration of space have been closely coupled throughout their short histories. In this presentation, we will explore the space (and space launch) environments as drivers of printed circuit design, a brief history of NASA's use of printed electronic circuits, and we will examine future requirements for such circuits in our continued exploration of space.

Spaceflight induces changes in the synaptic circuitry of the postnatal developing neocortex

NASA Technical Reports Server (NTRS)

DeFelipe, J.; Arellano, J. I.; Merchan-Perez, A.; Gonzalez-Albo, M. C.; Walton, K.; Llinas, R.

2002-01-01

The establishment of the adult pattern of neocortical circuitry depends on various intrinsic and extrinsic factors, whose modification during development can lead to alterations in cortical organization and function. We report the effect of 16 days of spaceflight [Neurolab mission; from postnatal day 14 (P14) to P30] on the neocortical representation of the hindlimb synaptic circuitry in rats. As a result, we show, for the first time, that development in microgravity leads to changes in the number and morphology of cortical synapses in a laminar-specific manner. In the layers II/III and Va, the synaptic cross-sectional lengths were significantly larger in flight animals than in ground control animals. Flight animals also showed significantly lower synaptic densities in layers II/III, IV and Va. The greatest difference was found in layer II/III, where there was a difference of 344 million synapses per mm(3) (15.6% decrease). Furthermore, after a 4 month period of re-adaptation to terrestrial gravity, some changes disappeared (i.e. the alterations were transient), while conversely, some new differences also appeared. For example, significant differences in synaptic density in layers II/III and Va after re-adaptation were no longer observed, whereas in layer IV the density of synapses increased notably in flight animals (a difference of 185 million synapses per mm(3) or 13.4%). In addition, all the changes observed only affected asymmetrical synapses, which are known to be excitatory. These results indicates that terrestrial gravity is a necessary environmental parameter for normal cortical synaptogenesis. These findings are fundamental in planning future long-term spaceflights.

Next Steps in the Evolution of Human Spaceflight Training

NASA Technical Reports Server (NTRS)

Balmain, Clint; Niemann, Chris; McGregor, Darrell

2011-01-01

Train before you fly has always been a watchword at NASA, and consequently, NASA has been conducting training for human spaceflight missions for longer than it has been involved in the actual conduct of human spaceflight missions. Throughout that time, NASA s approach to human spaceflight training has continuously evolved to keep pace with the technology of the modern world, but the approach to training itself has not changed significantly. Today, there are more tools and technologies that enable learning than ever before. This paper intends to review the challenges of human spaceflight training and how modern technology and an updated approach could improve that training. The Spaceflight Training Management Office (DA7) within the Mission Operations Directorate (MOD) has been investigating the current training of instructors, flight controllers and astronauts in order to identify where a new approach to training and training management may be necessary to improve the efficacy of the training provided. Through this investigation, the DA7 team has identified potential areas of improvement within International Space Station (ISS) training in a wide range of areas, including the delivery of training, the structure of the training program, the concept of what is considered training, and the management of that training. The ISS is an operational program with an established training paradigm. As such, the implementation of these concepts will be met with several challenges that may prevent or preclude them from being adopted. These challenges include demonstrating return-on-investment (ROI) and overcoming cultural or technological obstacles. This report will delve into the possible improvement areas for training, the future training concepts that are being considered, and the challenges associated with implementation. The paper will include concepts for utilization of Web 2.0 technologies, electronic learning, digital media, and other technologies in the development

Increasing the Size of the Microbial Biomass Altered Bacterial Community Structure which Enhances Plant Phosphorus Uptake

PubMed Central

Shen, Pu; Murphy, Daniel Vaughan; George, Suman J.; Lapis-Gaza, Hazel; Xu, Minggang

2016-01-01

Agricultural production can be limited by low phosphorus (P) availability, with soil P being constrained by sorption and precipitation reactions making it less available for plant uptake. There are strong links between carbon (C) and nitrogen (N) availability and P cycling within soil P pools, with microorganisms being an integral component of soil P cycling mediating the availability of P to plants. Here we tested a conceptual model that proposes (i) the addition of readily-available organic substrates would increase the size of the microbial biomass thus exhausting the pool of easily-available P and (ii) this would cause the microbial biomass to access P from more recalcitrant pools. In this model it is hypothesised that the size of the microbial population is regulating access to less available P rather than the diversity of organisms contained within this biomass. To test this hypothesis we added mixtures of simple organic compounds that reflect typical root exudates at different C:N ratios to a soil microcosm experiment and assessed changes in soil P pools, microbial biomass and bacterial diversity measures. We report that low C:N ratio (C:N = 12.5:1) artificial root exudates increased the size of the microbial biomass while high C:N ratio (C:N = 50:1) artificial root exudates did not result in a similar increase in microbial biomass. Interestingly, addition of the root exudates did not alter bacterial diversity (measured via univariate diversity indices) but did alter bacterial community structure. Where C, N and P supply was sufficient to support plant growth the increase observed in microbial biomass occurred with a concurrent increase in plant yield. PMID:27893833

Space Life Sciences at NASA: Spaceflight Health Policy and Standards

NASA Technical Reports Server (NTRS)

Davis, Jeffrey R.; House, Nancy G.

2006-01-01

implement an overall Risk Management and Analysis process. Currently NASA is drafting spaceflight health standards for neurosensory alterations, space radiation exposure, behavioral health, muscle atrophy, cardiovascular fitness, immunological compromise, bone demineralization, and nutrition.

Responses of motor and sensory neurons of rodents to spaceflight

NASA Technical Reports Server (NTRS)

Ishihara, A.; Ohira, Y.; Roy, R. R.; Nagaoka, S.; Sekiguchi, C.; Edgerton, V. R.

2000-01-01

Spinal motoneurons innervating skeletal muscles comprised predominantly of high oxidative fibers, i.e. slow oxidative and fast oxidative glycolytic, have higher oxidative enzyme activities than motoneurons innervating skeletal muscles comprised primarily of low oxidative fibers, i.e. fast glycolytic. These findings suggest that there is a close relationship between the oxidative phosphorylation capacity of a motoneuron and of the muscle fibers that it innervates. Since some skeletal muscles become faster and less oxidative after 4-14 days of spaceflight, it might be expected that oxidative enzyme activities in some motoneurons also may decrease after spaceflight. In addition, there is significant muscular atrophy after even short spaceflights and, therefore, it may be expected that some motoneurons associated with these muscles also would atrophy. In the present paper, we examine the issue of whether spaceflight induces changes in the oxidative enzyme activity and/or size of spinal motoneurons.

Centrifuge-simulated suborbital spaceflight in subjects with cardiac implanted devices.

PubMed

Blue, Rebecca S; Reyes, David P; Castleberry, Tarah L; Vanderploeg, James M

2015-04-01

Future commercial spaceflight participants (SFPs) with conditions requiring personal medical devices represent a unique challenge. The behavior under stress of cardiac implanted devices (CIDs) such as pacemakers is of special concern. No known data currently exist on how such devices may react to the stresses of spaceflight. We examined the responses of two volunteer subjects with CIDs to G forces in a centrifuge to evaluate how similar potential commercial SFPs might tolerate the forces of spaceflight. Two subjects, 75- and 79-yr-old men with histories of atrial fibrillation and implanted dual-lead, rate-responsive pacemakers, underwent seven centrifuge runs over 2 d. Day 1 consisted of two +Gz runs (peak = +3.5 Gz, run 2) and two +Gx runs (peak = +6.0 Gx, run 4). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +Gx/+Gz). Data collected included blood pressures, electrocardiograms, pulse oximetry, neurovestibular exams, and postrun questionnaires regarding motion sickness, disorientation, greyout, and other symptoms. Despite both subjects' significant medical histories, neither had abnormal physiological responses. Post-spin analysis demonstrated no lead displacement, damage, or malfunction of either CID. Potential risks to SFPs with CIDs include increased arrhythmogenesis, lead displacement, and device damage. There are no known prior studies of individuals with CIDs exposed to accelerations anticipated during the dynamic phases of suborbital spaceflight. These cases demonstrate that even individuals with significant medical histories and implanted devices can tolerate the acceleration exposures of commercial spaceflight. Further investigation will determine which personal medical devices present significant risks during suborbital flight and beyond.

Human Spaceflight Safety Hearing

NASA Image and Video Library

2009-12-02

U.S. Rep. Gabrielle Giffords, D-Ariz., left, speaks with reitred astronaut Lt. Gen. Thomas Stafford prior to the start of a hearing before the House Subcommitte on Space and Aeronautics regarding Safety of Human Spaceflight on Capitol Hill, Wednesday, Dec. 2, 2009, in Washington. Photo Credit: (NASA/Bill Ingalls)

Technology assessment of human spaceflight - Combining philosophical and technical issues

NASA Astrophysics Data System (ADS)

Fromm, J.; Hoevelmann, G. H.

1992-08-01

A transutilitarian rationale is proposed for assessing human spaceflight that is based on objectives for these endeavors and ethical norms of conduct. Specific attention is given to: presupposed/tacit reasons for including man in spaceflight and the restricted notion of rational/justifiable activity. It is shown that economic rationale is insufficient and unsuitable as a means for assessing manned spaceflight, and transutilitarian objectives are compiled that contribute to the motivation for manned flight. The transutilitarian motivations include: pioneering uncharted territory, enhancing national prestige, establishing space-related autonomy, promoting international cooperation, and enhancing science and the quality of human life.

Calcium metabolism and cardiovascular function after spaceflight

NASA Technical Reports Server (NTRS)

Hatton, Daniel C.; Yue, Qi; Dierickx, Jacqueline; Roullet, Chantal; Otsuka, Keiichi; Watanabe, Mitsuaki; Coste, Sarah; Roullet, Jean Baptiste; Phanouvang, Thongchan; Orwoll, Eric;

Behavioral Assessment of Spaceflight Effects on Neurocognitive Performance - Extent and Longevity

NASA Technical Reports Server (NTRS)

De Dios, Y.E.; Kofman, I.S.; Gadd, N.E.; Kreutzberg, G.A.; Peters, B.T.; Taylor, L.C.; Campbell, D.J.; Wood, S.J.; Bloomberg, J.J.; Seidler, R.D.;

Effect of a 17 day spaceflight on contractile properties of human soleus muscle fibres

PubMed Central

Widrick, J J; Knuth, S T; Norenberg, K M; Romatowski, J G; Bain, J L W; Riley, D A; Karhanek, M; Trappe, S W; Trappe, T A; Costill, D L; Fitts, R H

1999-01-01

Soleus biopsies were obtained from four male astronauts 45 days before and within 2 h after a 17 day spaceflight. For all astronauts, single chemically skinned post-flight fibres expressing only type I myosin heavy chain (MHC) developed less average peak Ca2+ activated force (Po) during fixed-end contractions (0.78 ± 0.02 vs. 0.99 ± 0.03 mN) and shortened at a greater mean velocity during unloaded contractions (Vo) (0.83 ± 0.02 vs. 0.64 ± 0.02 fibre lengths s−1) than pre-flight type I fibres. The flight-induced decline in absolute Po was attributed to reductions in fibre diameter and/or Po per fibre cross-sectional area. Fibres from the astronaut who experienced the greatest relative loss of peak force also displayed a reduction in Ca2+ sensitivity. The elevated Vo of the post-flight slow type I fibres could not be explained by alterations in myosin heavy or light chain composition. One alternative possibility is that the elevated Vo resulted from an increased myofilament lattice spacing. This hypothesis was supported by electron micrographic analysis demonstrating a reduction in thin filament density post-flight. Post-flight fibres shortened at 30 % higher velocities than pre-flight fibres at external loads associated with peak power output. This increase in shortening velocity either reduced (2 astronauts) or prevented (2 astronauts) a post-flight loss in fibre absolute peak power (μN (fibre length) s−1). The changes in soleus fibre diameter and function following spaceflight were similar to those observed after 17 days of bed rest. Although in-flight exercise countermeasures probably reduced the effects of microgravity, the results support the idea that ground-based bed rest can serve as a model of human spaceflight. In conclusion, 17 days of spaceflight decreased force and increased shortening velocity of single Ca2+-activated muscle cells expressing type I MHC. The increase in shortening velocity greatly reduced the impact that impaired force

Effect of a 17 day spaceflight on contractile properties of human soleus muscle fibres

NASA Technical Reports Server (NTRS)

Widrick, J. J.; Knuth, S. T.; Norenberg, K. M.; Romatowski, J. G.; Bain, J. L.; Riley, D. A.; Karhanek, M.; Trappe, S. W.; Trappe, T. A.; Costill, D. L.;

Norepinephrine content in discrete brain areas and neurohypophysial vasopressin in rats after a 9-d spaceflight (SLS-1)

NASA Technical Reports Server (NTRS)

Fareh, Jeannette; Cottet-Emard, Jean-Marie; Pequignot, Jean-Marc; Jahns, Gary; Meylor, John; Viso, Michel; Vassaux, Didier; Gauquelin, Guillemette; Gharib, Claude

1993-01-01

The norepinephrine (NE) content in discrete brain areas and the vasopressin content in the neurohypophysial system were assessed in rats after a 9-d spaceflight and after a recovery period. The NE content in the locus coeruleus decreased significantly in spaceflight rats, but showed no difference between control and flight animals after a 9-d recovery. These findings were probably due to an acute stress undergone during landing. The NE content was unchanged in the A2 and A5 cell groups. In rats flown aboard SLS-1, the vasopressin content was increased in the posterior pituitary, and was significantly decreased in the hypothalamus. We conclude that the NE depletion in the locus coeruleus and the alteration in vasopressin release were consistent with an acute stress, likely occurring during and/or after landing. These changes tend to mask the actual neuroendocrine modifications caused by microgravity.

CCSDS - Advancing Spaceflight Technology for International Collaboration

NASA Technical Reports Server (NTRS)

Kearney, Mike; Kiely, Aaron; Yeh, Penshu; Gerner, Jean-Luc; Calzolari, Gian-Paolo; Gifford, Kevin; Merri, Mario; Weiss, Howard

2010-01-01

The Consultative Committee for Space Data Systems (CCSDS) has been developing data and communications standards since 1982, with the objective of providing interoperability for enabling international collaboration for spaceflight missions. As data and communications technology has advanced, CCSDS has progressed to capitalize on existing products when available and suitable for spaceflight, and to develop innovative new approaches when available products fail. The current scope of the CCSDS architecture spans the end-to-end data architecture of a spaceflight mission, with ongoing efforts to develop and standardize cutting-edge technology. This manuscript describes the overall architecture, the position of CCSDS in the standards and international mission community, and some CCSDS processes. It then highlights in detail several of the most interesting and critical technical areas in work right now, and how they support collaborative missions. Special topics include: Delay/Disruption Tolerant Networking (DTN), Asynchronous Message Service (AMS), Multispectral/Hyperspectral Data Compression (MHDC), Coding and Synchronization, Onboard Wireless, Spacecraft Monitor and Control, Navigation, Security, and Time Synchronization/Correlation. Broad international participation in development of CCSDS standards is encouraged.

Urolithiasis and Genitourinary Systems Issues for Spaceflight

NASA Astrophysics Data System (ADS)

Jones, Jeffrey A.; Sargsyan, Ashot; Pietryzk, Robert; Sams, C.; Stepaniak, Phillip; Whitson, P.

2008-09-01

Genitourinary medical events have shown to be an issue for both short duration and long duration spaceflight, and are anticipated to also be a potential issue for future exploration missions as well. This is based on actual historical pre-, in- and post-flight medical events, as well as assessment of what future flight challenges lay ahead. For this study, retrospective record review, as well as prospective studies of ultrasound and contingency management procedure development, and oral urinary stone prophylaxis were conducted. Results showed that the incidence of prior urinary calculi in- and post-flight was a risk driver for development of on-orbit countermeasures, as well as diagnostic and therapeutic methods for a possible in-flight calculus contingency. Oral potassium citrate and bisphosphonate preparations show promise for prophylaxis in spaceflight risk reduction. We conclude that a properly developed approach of selection, monitoring, and preventive medicine with effective countermeasures, along with early imaging diagnosis and minimally-invasive contingency intervention, should prevent issues such as urinary calculi from having a significant mission impact for exploration-class spaceflight.

Plasma Cytokine Levels During Long-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Crucian, Brian E.; Zwart, Sara R.; Quiriarte, Heather A.; Smith, Scott M.; Sams, Clarence F.

2012-01-01

Determine the in-flight status of immunity, physiological stress, viral immunity/reactivation. Specific measurements include leukocyte distribution, T cell function, cytokine production profiles (mRNA, intracellular, secreted, plasma), virus-specific T cell number/function, latent herpesvirus reactivation, stress hormone levels. Determine the clinical risk related to immune dysregulation for exploration class spaceflight, as well as an appropriate monitoring strategy for spaceflight-associated immune dysfunction, that could be used for the evaluation of countermeasures. Specific Study Objectives: Determine the nutritional status of astronauts before, during, and after spaceflight ensure adequate intake of energy, protein, and vitamins during missions. The Clinical Nutritional Status Assessment measures dietary intake, body composition, protein, bone, iron, mineral, vitamin, and antioxidant status (60 total analytes). Currently, it is a medical requirement for U.S. crewmembers on-board the ISS. The results of data analysis are used both to understand the connections between nutrition and human health during space flight, and to develop effective dietary strategies to reduce adverse health impacts (including bone loss, loss of important vitamins and minerals, and increased genetic damage from radiation).

The Effect of Spaceflight on Cartilage Cell Cycle and Differentiation

NASA Technical Reports Server (NTRS)

Doty, Stephen B.; Stiner, Dalina; Telford, William G.

2000-01-01

In vivo studies have shown that spaceflight results in loss of bone and muscle. In an effort to understand the mechanisms of these changes, cell cultures of cartilage, bone and muscle have been subjected to spaceflight to study the microgravity effects on differentiated cells. However it now seems possible that the cell differentiation process itself may be the event(s) most affected by spaceflight. For example, osteoblast-like cells have been shown to have reduced cellular activity in microgravity due to an underdifferentiated state (Carmeliet, et al, 1997). And reduced human lymphocyte growth in spaceflight was related to increased apoptosis (Lewis, et al, 1998). Which brings us to the question of whether reduced cellular activity in space is due to an effect on the differentiated cell, an effect on the cell cycle and cell proliferation, or an effect on cell death. This question has not been specifically addressed on previous flights and was the question behind die present study.

Incidence of Epstein-Barr Virus in Astronaut Saliva During Spaceflight

NASA Technical Reports Server (NTRS)

Payne, Deborah A.; Mehta, Satish K.; Tyring, Stephen K.; Stowe, Raymond P.; Pierson, Duane L.

1998-01-01

Astronauts experience psychological and physical stresses that may result in re-activation of latent viruses during spaceflight, potentially increasing the risk of disease among crew members. The shedding of Epstein-Barr virus (EBV) in the saliva of astronauts will increase during spaceflight. A total of 534 saliva specimens were collected from 11 EBV-seropositive astronauts before, during, and after four space shuttle missions. The presence of EBV DNA in saliva, assessed by polymerase chain reaction (PCR), was used to determine shedding patterns before, during, and after spaceflight. EBV DNA was detected more frequently before flight than during (p less than 0.001) or after (p less than 0.01) flight. No significant difference between the in-flight and postflight periods was detected in the frequency of occurrence of EBV DNA. The increased frequency of shedding of EBV before flight suggests that stress levels may be greater before launch than during or after spaceflight.

Machine Learning Approaches to Increasing Value of Spaceflight Omics Databases

NASA Technical Reports Server (NTRS)

Gentry, Diana

2017-01-01

The number of spaceflight bioscience mission opportunities is too small to allow all relevant biological and environmental parameters to be experimentally identified. Simulated spaceflight experiments in ground-based facilities (GBFs), such as clinostats, are each suitable only for particular investigations -- a rotating-wall vessel may be 'simulated microgravity' for cell differentiation (hours), but not DNA repair (seconds) -- and introduce confounding stimuli, such as motor vibration and fluid shear effects. This uncertainty over which biological mechanisms respond to a given form of simulated space radiation or gravity, as well as its side effects, limits our ability to baseline spaceflight data and validate mission science. Machine learning techniques autonomously identify relevant and interdependent factors in a data set given the set of desired metrics to be evaluated: to automatically identify related studies, compare data from related studies, or determine linkages between types of data in the same study. System-of-systems (SoS) machine learning models have the ability to deal with both sparse and heterogeneous data, such as that provided by the small and diverse number of space biosciences flight missions; however, they require appropriate user-defined metrics for any given data set. Although machine learning in bioinformatics is rapidly expanding, the need to combine spaceflight/GBF mission parameters with omics data is unique. This work characterizes the basic requirements for implementing the SoS approach through the System Map (SM) technique, a composite of a dynamic Bayesian network and Gaussian mixture model, in real-world repositories such as the GeneLab Data System and Life Sciences Data Archive. The three primary steps are metadata management for experimental description using open-source ontologies, defining similarity and consistency metrics, and generating testing and validation data sets. Such approaches to spaceflight and GBF omics data may

The next phase of life-sciences spaceflight research

PubMed Central

Etheridge, Timothy; Nemoto, Kanako; Hashizume, Toko; Mori, Chihiro; Sugimoto, Tomoko; Suzuki, Hiromi; Fukui, Keiji; Yamazaki, Takashi; Higashibata, Akira; Higashitani, Atsushi

2011-01-01

Recently we demonstrated that the effectiveness of RNAi interference (RNAi) for inhibiting gene expression is maintained during spaceflight in the worm Caenorhabditis elegans and argued for the biomedical importance of this finding. We also successfully utilized green fluorescent protein (GFP)-tagged proteins to monitor changes in GPF localization during flight. Here we discuss potential applications of RNAi and GFP in spaceflight studies and the ramifications of these experiments for the future of space life-sciences research. PMID:22446523

House Subcommittee - Manned Spaceflight - MSC

NASA Image and Video Library

1964-02-15

George Low, Joseph Piland, Philip Hamburger, Congressman Olin Teague from Texas; and, Congressman Joe D. Waggoner from Louisiana at the entrance to Site 1, Clear Lake, prior to briefing for the House Subcommittee on Manned Spaceflight. MSC, Houston, TX

Long-Duration Spaceflight Increases Depth Ambiguity of Reversible Perspective Figures

PubMed Central

Clément, Gilles; Allaway, Heather C. M.; Demel, Michael; Golemis, Adrianos; Kindrat, Alexandra N.; Melinyshyn, Alexander N.; Merali, Tahir; Thirsk, Robert

2015-01-01

The objective of this study was to investigate depth perception in astronauts during and after spaceflight by studying their sensitivity to reversible perspective figures in which two-dimensional images could elicit two possible depth representations. Other ambiguous figures that did not give rise to a perception of illusory depth were used as controls. Six astronauts and 14 subjects were tested in the laboratory during three sessions for evaluating the variability of their responses in normal gravity. The six astronauts were then tested during four sessions while on board the International Space Station for 5–6 months. They were finally tested immediately after return to Earth and up to one week later. The reaction time decreased throughout the sessions, thus indicating a learning effect. However, the time to first percept reversal and the number of reversals were not different in orbit and after the flight compared to before the flight. On Earth, when watching depth-ambiguous perspective figures, all subjects reported seeing one three-dimensional interpretation more often than the other, i.e. a ratio of about 70–30%. In weightlessness this asymmetry gradually disappeared and after 3 months in orbit both interpretations were seen for the same duration. These results indicate that the perception of “illusory” depth is altered in astronauts during spaceflight. This increased depth ambiguity is attributed to the lack of the gravitational reference and the eye-ground elevation for interpreting perspective depth cues. PMID:26146839

Long-Duration Spaceflight Increases Depth Ambiguity of Reversible Perspective Figures.

PubMed

Clément, Gilles; Allaway, Heather C M; Demel, Michael; Golemis, Adrianos; Kindrat, Alexandra N; Melinyshyn, Alexander N; Merali, Tahir; Thirsk, Robert

2015-01-01

The objective of this study was to investigate depth perception in astronauts during and after spaceflight by studying their sensitivity to reversible perspective figures in which two-dimensional images could elicit two possible depth representations. Other ambiguous figures that did not give rise to a perception of illusory depth were used as controls. Six astronauts and 14 subjects were tested in the laboratory during three sessions for evaluating the variability of their responses in normal gravity. The six astronauts were then tested during four sessions while on board the International Space Station for 5-6 months. They were finally tested immediately after return to Earth and up to one week later. The reaction time decreased throughout the sessions, thus indicating a learning effect. However, the time to first percept reversal and the number of reversals were not different in orbit and after the flight compared to before the flight. On Earth, when watching depth-ambiguous perspective figures, all subjects reported seeing one three-dimensional interpretation more often than the other, i.e. a ratio of about 70-30%. In weightlessness this asymmetry gradually disappeared and after 3 months in orbit both interpretations were seen for the same duration. These results indicate that the perception of "illusory" depth is altered in astronauts during spaceflight. This increased depth ambiguity is attributed to the lack of the gravitational reference and the eye-ground elevation for interpreting perspective depth cues.

Embryogenesis, hatching and larval development of Artemia during orbital spaceflight

NASA Technical Reports Server (NTRS)

Spooner, B. S.; Debell, L.; Armbrust, L.; Guikema, J. A.; Metcalf, J.; Paulsen, A.

1994-01-01

Developmental biology studies, using gastrula-arrested cysts of the brine shrimp Artemia franciscana, were conducted during two flights of the space shuttle Atlantis (missions STS-37 and STS-43) in 1991. Dehydrated cysts were activated, on orbit, by addition of salt water to the cysts, and then development was terminated by the addition of fixative. Development took place in 5 ml syringes, connected by tubing to activation syringes, containing salt water, and termination syringes, containing fixative. Comparison of space results with simultaneous ground control experiments showed that equivalent percentages of naupliar larvae hatched in the syringes (40%). Thus, reactivation of development, completion of embryogenesis, emergence and hatching took place, during spaceflight, without recognizable alteration in numbers of larvae produced. Post-hatching larval development was studied in experiments where development was terminated, by introduction of fixative, 2 days, 4 days, and 8 days after reinitiation of development. During spaceflight, successive larval instars or stages, interrupted by molts, occurred, generating brine shrimp at appropriate larval instars. Naupliar larvae possessed the single naupliar eye, and development of the lateral pair of adult eyes also took place in space. Transmission electron microscopy revealed extensive differentiation, including skeletal muscle and gut endoderm, as well as the eye tissues. These studies demonstrate the potential value of Artemia for developmental biology studies during spa ceflight, and show that extensive degrees of development can take place in this microgravity environment.

Subject anxiety and psychological considerations for centrifuge-simulated suborbital spaceflight.

PubMed

Mulcahy, Robert A; Blue, Rebecca S; Vardiman, Johnené L; Mathers, Charles H; Castleberry, Tarah L; Vanderploeg, James M

2014-08-01

Anxiety and psychological concerns may pose a challenge to future commercial spaceflight. To help identify potential measures of anxiousness and indicators of flight-related stress, the psychiatric histories and anxiousness responses of volunteers exposed to G forces in centrifuge-simulated spaceflight acceleration profiles were examined. Over 2 d, 86 individuals (63 men, 23 women), 20-78 yr old, underwent up to 7 centrifuge runs. Day 1 consisted of two +G(z) runs (peak = +3.5 G(z)) and two +Gx runs (peak = +6.0 G(x)). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +G(x) and +G(z)). Hemodynamic data were collected during the profiles. Subjects completed a retrospective self-report anxiety questionnaire. Medical monitors identified individuals exhibiting varying degrees of anxiousness during centrifuge exposure, medical histories of psychiatric disease, and other potential indicators of psychological intolerance of spaceflight. The retrospective survey identified 18 individuals self-reporting anxiousness, commonly related to unfamiliarity with centrifuge acceleration and concerns regarding medical history. There were 12 individuals (5 men, 7 women, average age 46.2 yr) who were observed to have anxiety that interfered with their ability to complete training; of these, 4 reported anxiousness on their questionnaire and 9 ultimately completed the centrifuge profiles. Psychiatric history was not significantly associated with anxious symptoms. Anxiety is likely to be a relevant and potentially disabling problem for commercial spaceflight participants; however, positive psychiatric history and self-reported symptoms did not predict anxiety during centrifuge performance. Symptoms of anxiousness can often be ameliorated through training and coaching. Even highly anxious individuals are likely capable of tolerating commercial spaceflight.

Immune System Dysregulation and Herpesvirus Reactivation Persist During Long-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Crucian, B. E.; Stowe, R. P.; Mehta, S.; Uchakin, P.; Quiriarte, H.; Pierson, D.; Sams, C. F.

2010-01-01

Background: Immunity, latent herpesvirus reactivation, physiological stress and circadian rhythms were assessed during six month spaceflight onboard ISS. Blood and saliva samples were collected early, mid and late in-flight and returned for immediate analysis. Mid-point study data (10 of 17 planned subjects) will be presented. Results: Some shifts in leukocyte distribution occurred during flight, including alterations in CD8+ T cell maturation. General T cell function was consistently reduced early in-flight. Levels CD8+/IFNg+ producing T cells were depressed early in-flight, and immediately upon landing. Persistent mitogen-dependant reductions were observed in IFNg, IL-17a, IL-10, TNFa and IL-6 production. Monocyte production of IL-10 was reduced, whereas IL-8 levels were increased. Levels of mRNA for the TNFa, IL-6 and IFNg were transiently elevated early in-flight, and the dynamics of TNF and IL-6 gene expression were somewhat antagonistic to their corresponding receptors during flight. The number of virus-specific CD8+ T-cells was measured using MHC tetramers, while their function was measured using intracellular cytokine analysis following peptide stimulation. Both the number and function of EBV-specific cells decreased during flight as compared to preflight levels. The number of CMV-specific T-cells generally increased as the mission progressed while their function was variable. Viral (EBV) load in blood was elevated postflight. Anti-EBV VCA antibodies were significantly elevated by R+0; anti-EA antibodies were not significantly elevated at landing; and anti-CMV antibodies were somewhat elevated during flight. Higher levels of salivary EBV DNA were found during flight. VZV DNA reactivation occurred in 50 % of astronauts during flight, continuing for up to 30 days post-flight. CMV was shed in 35 % the in-flight and 30% of postflight urine samples of the crewmembers. There was generally a higher level of cortisol as measured in urine and saliva in the

Spaceflight Flow Cytometry: Design Challenges and Applications

NASA Technical Reports Server (NTRS)

Pappas, Dimitri; Kao, Shih-Hsin; Jeevarajan, Antony S.

2004-01-01

Future space exploration missions will require analytical technology capable of providing both autonomous medical care to the crew and investigative capabilities to researchers. While several promising candidate technologies exist for further development, flow cytometry is an attractive technology as it offers both crew health and a wide array of biochemistry and immunology assays. While flow cytometry has been widely used for cellular analysis in both clinical and research settings, the requirements for proper operation in spaceflight impose constraints on any instrument designs. The challenges of designing a spaceflight-ready flow cytometer are discussed, as well as some preliminary results using a prototype system.

Deoxygenation alters bacterial diversity and community composition in the ocean’s largest oxygen minimum zone

NASA Astrophysics Data System (ADS)

Beman, J. Michael; Carolan, Molly T.

2013-10-01

Oceanic oxygen minimum zones (OMZs) have a central role in biogeochemical cycles and are expanding as a consequence of climate change, yet how deoxygenation will affect the microbial communities that control these cycles is unclear. Here we sample across dissolved oxygen gradients in the oceans’ largest OMZ and show that bacterial richness displays a unimodal pattern with decreasing dissolved oxygen, reaching maximum values on the edge of the OMZ and decreasing within it. Rare groups on the OMZ margin are abundant at lower dissolved oxygen concentrations, including sulphur-cycling Chromatiales, for which 16S rRNA was amplified from extracted RNA. Microbial species distribution models accurately replicate community patterns based on multivariate environmental data, demonstrate likely changes in distributions and diversity in the eastern tropical North Pacific Ocean, and highlight the sensitivity of key bacterial groups to deoxygenation. Through these mechanisms, OMZ expansion may alter microbial composition, competition, diversity and function, all of which have implications for biogeochemical cycling in OMZs.

Frequent premature ventricular contractions in an orbital spaceflight participant.

PubMed

Jennings, Richard T; Stepanek, Jan P; Scott, Luis R; Voronkov, Yury I

2010-06-01

Commercial spaceflight participants on orbital flights typically are older than career astronauts and they often have medical conditions that have not been studied at high g or in microgravity. This is a case report of a 56-yr-old orbital spaceflight participant with essential tremor and frequent premature ventricular contractions that occurred at rates up to 7000 per day. Before training and spaceflight, he was required to complete extensive clinical investigations to demonstrate normal cardiac structures and the absence of cardiac pathology. The evaluation included signal averaged ECG, transthoracic stress echocardiography, exercise tolerance tests, electrophysiological studies, cardiac MRI, electron beam CT, Holter monitoring, and overnight oximetry. While no cardiac pathology was demonstrated, the Russian medical team required that the PVCs be treated prior to training and spaceflight. For the initial flight, a selective beta-1 receptor beta blocker was used and for the second a calcium channel blocker was used in combination with a nonselective beta blocker for tremor control. Analogue environment testing assured that this combination of medications was compatible. The spaceflight participant's PVCs were incompletely suppressed with a low-dose selective beta-1 blocker, but were well suppressed by a calcium channel blocker. He tolerated in-flight periodic use of a nonselective beta blocker in combination with a calcium channel blocker. In-flight ECG and blood pressure monitoring results were normal, and an ECG obtained midmission and on landing day showed successful PVC suppression. He did not have any cardiac difficulty with launch, on-orbit operations, entry, or recovery

Efficiency Management in Spaceflight Systems

NASA Technical Reports Server (NTRS)

Murphy, Karen

2016-01-01

Efficiency in spaceflight is often approached as “faster, better, cheaper – pick two”. The high levels of performance and reliability required for each mission suggest that planners can only control for two of the three. True efficiency comes by optimizing a system across all three parameters. The functional processes of spaceflight become technical requirements on three operational groups during mission planning: payload, vehicle, and launch operations. Given the interrelationships among the functions performed by the operational groups, optimizing function resources from one operational group to the others affects the efficiency of those groups and therefore the mission overall. This paper helps outline this framework and creates a context in which to understand the effects of resource trades on the overall system, improving the efficiency of the operational groups and the mission as a whole. This allows insight into and optimization of the controlling factors earlier in the mission planning stage.

Topics in space gerontology: Effects of altered gravity and the problem of biological age

NASA Technical Reports Server (NTRS)

Economos, A. C.

1982-01-01

The use of altered gravity experimentation as a gerontological research tool is examined and a rationale for a systems approach to the adaptation to spaceflight is presented. The dependence of adaptation capacity on biological age is also discussed.

Molecular Mechanisms of Circadian Regulation During Spaceflight

NASA Technical Reports Server (NTRS)

Zanello, Susana; Boyle, Richard

2011-01-01

Disruption of the regular environmental circadian cues in addition to stringent and demanding operational schedules are two main factors that undoubtedly impact sleep patterns and vigilant performance in the astronaut crews during spaceflight. Most research is focused on the behavioral aspects of the risk of circadian desynchronization, characterized by fatigue and health and performance decrement. A common countermeasure for circadian re-entrainment utilizes blue-green light to entrain the circadian clock and mitigate this risk. However, an effective countermeasure targeting the photoreceptor system requires that the basic circadian molecular machinery remains intact during spaceflight. The molecular clock consists of sets of proteins that perform different functions within the clock machinery: circadian oscillators (genes whose expression levels cycle during the day, keep the pass of cellular time and regulate downstream effector genes), the effector or output genes (those which impact the physiology of the tissue or organism), and the input genes (responsible for sensing the environmental cues that allow circadian entrainment). The main environmental cue is light. As opposed to the known photoreceptors (rods and cones), the non-visual light stimulus is received by a subset of the population of retinal ganglion cells called intrinsically photosensitive retinal ganglion cells (ipRGC) that express melanopsin (opsin 4 -Opn4-) as the photoreceptor. We hypothesize that spaceflight may affect ipRGC and melanopsin expression, which may be a contributing cause of circadian disruption during spaceflight. To answer this question, eyes from albino Balb/cJ mice aboard STS-133 were collected for histological analysis and gene expression profiling of the retina at 1 and 7 days after landing. Both vivarium and AEM (animal enclosure module) mice were used as ground controls. Opn4 expression was analyzed by real time RT/qPCR and retinal sections were stained for Opn4

Experimental sulfate amendment alters peatland bacterial community structure.

PubMed

Strickman, R J S; Fulthorpe, R R; Coleman Wasik, J K; Engstrom, D R; Mitchell, C P J

2016-10-01

As part of a long-term, peatland-scale sulfate addition experiment, the impact of varying sulfate deposition on bacterial community responses was assessed using 16S tag encoded pyrosequencing. In three separate areas of the peatland, sulfate manipulations included an eight year quadrupling of atmospheric sulfate deposition (experimental), a 3-year recovery to background deposition following 5years of elevated deposition (recovery), and a control area. Peat concentrations of methylmercury (MeHg), a bioaccumulative neurotoxin, were measured, the production of which is attributable to a growing list of microorganisms, including many sulfate-reducing Deltaproteobacteria. The total bacterial and Deltaproteobacterial community structures in the experimental treatment differed significantly from those in the control and recovery treatments that were either indistinguishable or very similar to one another. Notably, the relatively rapid return (within three years) of bacterial community structure in the recovery treatment to a state similar to the control, demonstrates significant resilience of the peatland bacterial community to changes in atmospheric sulfate deposition. Changes in MeHg accumulation between sulfate treatments correlated with changes in the Deltaproteobacterial community, suggesting that sulfate may affect MeHg production through changes in the community structure of this group. Copyright © 2016 Elsevier B.V. All rights reserved.

Recovery of postural equilibrium control following spaceflight

NASA Technical Reports Server (NTRS)

Paloski, W. H.; Reschke, M. F.; Black, F. O.; Doxey, D. D.; Harm, D. L.

1992-01-01

Decreased postural stability is observed in most astronauts immediately following spaceflight. Because ataxia may present postflight operational hazards, it is important to determine the incidence of postural instability immediately following landing and the dynamics of recovery of normal postural equilibrium control. It is postulated that postflight postural instability results from in-flight adaptive changes in central nervous system (CNS) processing of sensory information from the visual, vestibular, and proprioceptive systems. The purpose of the present investigation was to determine the magnitude and time course of postflight recovery of postural equilibrium control and, hence, readaptation of CNS processing of sensory information. Thirteen crew members from six spaceflight missions were studied pre- and postflight using a modified commercial posturography system. Postural equilibrium control was found to be seriously disrupted immediately following spaceflight in all subjects. Readaptation to the terrestrial environment began immediately upon landing, proceeded rapidly for the first 10-12 hours, and then proceeded much more slowly for the subsequent 2-4 days until preflight stability levels were reachieved. It is concluded that the overall postflight recovery of postural stability follows a predictable time course.

Medical qualification of a commercial spaceflight participant: not your average astronaut.

PubMed

Jennings, Richard T; Murphy, David M F; Ware, David L; Aunon, Serena M; Moon, Richard E; Bogomolov, Valery V; Morgun, Valeri V; Voronkov, Yuri I; Fife, Caroline E; Boyars, Michael C; Ernst, Randy D

2006-05-01

Candidates for commercial spaceflight may be older than the typical astronaut and more likely to have medical problems that place them at risk during flight. Since the effects of microgravity on many medical conditions are unknown, physicians have little guidance when evaluating and certifying commercial spaceflight participants. This dynamic new era in space exploration may provide important data for evaluating medical conditions, creating appropriate medical standards, and optimizing treatment alternatives for long-duration spaceflight. A 57-yr-old spaceflight participant for an ISS mission presented with medical conditions that included moderately severe bullous emphysema, previous spontaneous pneumothorax with talc pleurodesis, a lung parenchymal mass, and ventricular and atrial ectopy. The medical evaluation required for certification was extensive and included medical studies and monitoring conducted in analogue spaceflight environments including altitude chambers, high altitude mixed-gas simulation, zero-G aircraft, and high-G centrifuge. To prevent recurrence of pneumothorax, we performed video-assisted thoracoscopic pleurodesis, and to assess lung masses, several percutaneous or direct biopsies. The candidate's 10-d mission was without incident. Non-career astronauts applying for commercial suborbital and orbital spaceflight will, at least in the near future, challenge aerospace physicians with unknowns regarding safety during training and flight, and highlight important ethical and risk-assessment problems. The information obtained from this new group of space travelers will provide important data for the evaluation and in-flight treatment of medical problems that space programs have not yet addressed systematically, and may improve the medical preparedness of exploration-class missions.

Flexor bias of joint position in humans during spaceflight

NASA Technical Reports Server (NTRS)

McCall, G. E.; Goulet, C.; Boorman, G. I.; Roy, R. R.; Edgerton, V. R.

2003-01-01

The ability to estimate ankle and elbow joint position was tested before, during, and after a 17-day spaceflight. Subjects estimated targeted joint angles during isovelocity (IsoV) joint movements with agonist muscle groups either active or relaxed. These movements included elbow extension (EE) and elbow flexion (EF), and plantarflexion (PF) and dorsiflexion (DF) of the ankle. Subjects also estimated these joint positions while moving the dynamometer at their chosen (variable) velocity (VarV) during EE and PF. For IsoV tests, no differences were observed between active and passive movements for either the ankle or elbow. Compared with those of pre-flight test days, estimates of targeted elbow joint angles were approximately 5 degrees to 15 degrees more flexed in-flight, and returned toward the pre-flight values during recovery. The spaceflight effects for the ankle were inconsistent and less prevalent than those for the elbow. The VarV PF test condition for the 120 degrees target angle at the ankle exhibited approximately 5 degrees to 7 degrees more DF target angle estimates in-flight compared with those pre- or post-flight. In contrast, during IsoV PF there was a tendency for ankle estimates to be approximately 2 degrees to 3 degrees more PF after 2-3 days exposure to spaceflight. These data indicate that during spaceflight the perception of elbow extension is greater than actuality, and are consistent with the interpretation that microgravity induced a flexor bias in the estimation of the actual elbow joint position. Moreover, these effects in joint proprioception during spaceflight were observed in individual isolated single-joint movements during tasks in which vestibular function in maintaining posture were minimal.

Flexor bias of joint position in humans during spaceflight.

PubMed

McCall, G E; Goulet, C; Boorman, G I; Roy, R R; Edgerton, V R

2003-09-01

The ability to estimate ankle and elbow joint position was tested before, during, and after a 17-day spaceflight. Subjects estimated targeted joint angles during isovelocity (IsoV) joint movements with agonist muscle groups either active or relaxed. These movements included elbow extension (EE) and elbow flexion (EF), and plantarflexion (PF) and dorsiflexion (DF) of the ankle. Subjects also estimated these joint positions while moving the dynamometer at their chosen (variable) velocity (VarV) during EE and PF. For IsoV tests, no differences were observed between active and passive movements for either the ankle or elbow. Compared with those of pre-flight test days, estimates of targeted elbow joint angles were approximately 5 degrees to 15 degrees more flexed in-flight, and returned toward the pre-flight values during recovery. The spaceflight effects for the ankle were inconsistent and less prevalent than those for the elbow. The VarV PF test condition for the 120 degrees target angle at the ankle exhibited approximately 5 degrees to 7 degrees more DF target angle estimates in-flight compared with those pre- or post-flight. In contrast, during IsoV PF there was a tendency for ankle estimates to be approximately 2 degrees to 3 degrees more PF after 2-3 days exposure to spaceflight. These data indicate that during spaceflight the perception of elbow extension is greater than actuality, and are consistent with the interpretation that microgravity induced a flexor bias in the estimation of the actual elbow joint position. Moreover, these effects in joint proprioception during spaceflight were observed in individual isolated single-joint movements during tasks in which vestibular function in maintaining posture were minimal.

Short-Duration Spaceflight Does Not Prolong QTc Intervals in Male Astronauts

NASA Technical Reports Server (NTRS)

Mitchell, Brett M.; Meck, Janice V.

2004-01-01

Although ventricular dysrhythmias are not increased during, and QTc intervals are not prolonged after, short-duration (5 to 16 days) spaceflights, QTc intervals have not previously been reported during these shorter flights. Holter monitor recordings, obtained in 11 male astronauts who flew on shuttle missions ranging from 5 to 10 days, showed that QTc intervals did not change significantly 10 days before launch, on 2 separate days of spaceflight, and 2 days after landing. Taken together, these data and our previous report show that QTc interval prolongation occurs sometime between the 9th and 30th days of spaceflight.

Bacterial endophytes enhance competition by invasive plants.

PubMed

Rout, Marnie E; Chrzanowski, Thomas H; Westlie, Tara K; DeLuca, Thomas H; Callaway, Ragan M; Holben, William E

2013-09-01

Invasive plants can alter soil microbial communities and profoundly alter ecosystem processes. In the invasive grass Sorghum halepense, these disruptions are consequences of rhizome-associated bacterial endophytes. We describe the effects of N2-fixing bacterial strains from S. halepense (Rout and Chrzanowski, 2009) on plant growth and show that bacteria interact with the plant to alter soil nutrient cycles, enabling persistence of the invasive. • We assessed fluxes in soil nutrients for ∼4 yr across a site invaded by S. halepense. We assayed the N2-fixing bacteria in vitro for phosphate solubilization, iron chelation, and production of the plant-growth hormone indole-3-acetic acid (IAA). We assessed the plant's ability to recruit bacterial partners from substrates and vertically transmit endophytes to seeds and used an antibiotic approach to inhibit bacterial activity in planta and assess microbial contributions to plant growth. • We found persistent alterations to eight biogeochemical cycles (including nitrogen, phosphorus, and iron) in soils invaded by S. halepense. In this context, three bacterial isolates solubilized phosphate, and all produced iron siderophores and IAA in vitro. In growth chamber experiments, bacteria were transmitted vertically, and molecular analysis of bacterial community fingerprints from rhizomes indicated that endophytes are also horizontally recruited. Inhibiting bacterial activity with antibiotics resulted in significant declines in plant growth rate and biomass, with pronounced rhizome reductions. • This work suggests a major role of endophytes on growth and resource allocation of an invasive plant. Indeed, bacterial isolate physiology is correlated with invader effects on biogeochemical cycles of nitrogen, phosphate, and iron.

Environmental Qualification of a Single-Crystal Silicon Mirror for Spaceflight Use

NASA Technical Reports Server (NTRS)

Hagopian, John; Chambers, John; Rohrback. Scott; Bly, Vincent; Morell, Armando; Budinoff, Jason

2013-01-01

This innovation is the environmental qualification of a single-crystal silicon mirror for spaceflight use. The single-crystal silicon mirror technology is a previous innovation, but until now, a mirror of this type has not been qualified for spaceflight use. The qualification steps included mounting, gravity change measurements, vibration testing, vibration- induced change measurements, thermal cycling, and testing at the cold operational temperature of 225 K. Typical mirrors used for cold applications for spaceflight instruments include aluminum, beryllium, glasses, and glass-like ceramics. These materials show less than ideal behavior after cooldown. Single-crystal silicon has been demonstrated to have the smallest change due to temperature change, but has not been spaceflight-qualified for use. The advantage of using a silicon substrate is with temperature stability, since it is formed from a stress-free single crystal. This has been shown in previous testing. Mounting and environmental qualification have not been shown until this testing.

KENNEDY SPACE CENTER, FLA. - Dr. Dennis Morrison, NASA Johnson Space Center, processes one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-07

KENNEDY SPACE CENTER, FLA. - Dr. Dennis Morrison, NASA Johnson Space Center, processes one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

KENNEDY SPACE CENTER, FLA. - The crystals visible in this laboratory dish were part of an experiment carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-07

KENNEDY SPACE CENTER, FLA. - The crystals visible in this laboratory dish were part of an experiment carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto, with Instrumentation Technology Associates, Inc., and Bob McLean, from the Southwest Texas State University, work on an experiment found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-06

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto, with Instrumentation Technology Associates, Inc., and Bob McLean, from the Southwest Texas State University, work on an experiment found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto (foreground), Instrumentation Technology Associates, Inc., examines one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-07

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto (foreground), Instrumentation Technology Associates, Inc., examines one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

KENNEDY SPACE CENTER, FLA. - Dr. Dennis Morrison, NASA Johnson Space Center, works with one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-07

KENNEDY SPACE CENTER, FLA. - Dr. Dennis Morrison, NASA Johnson Space Center, works with one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

Plasmid profiling of bacterial isolates from confined environments

NASA Astrophysics Data System (ADS)

van Houdt, Rob; Provoost, Ann; Coninx, Ilse; Leys, Natalie; Mergeay, Max

Plasmid profiling of bacterial isolates from confined environments R. Van Houdt, I. Coninx, A. Provoost, N. Leys, and M. Mergeay Expertise group for Molecular and Cellular Biology, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, B-2400 Mol, Belgium. Human exploration of extreme and isolated hostile environments such as space requires special confined small volume habitats to protect and house the crew. However, human confinement in such small volume habitats has restrictions on waste disposal and personal hygiene and inevitably generates a particular community of microorganisms within the habitat. These microorganisms are mainly originating from the crew (skin, mucous membranes, upper respiratory tract, mouth, and gastrointestinal tract) but also include the residing environmental microorganisms. Earth-based confined habitats such as the Antarctic Research Station Concordia are used as test beds for long-duration spaceflights to study the physiologic and psychological adaptation to isolated environments. The dynamics of the environmental microbial population in such a test bed could render additional insights in assessing the potential health risks in long-duration space missions. Not only total bacterial contamination levels are important, but it is essential to identify also the predominant microbial taxa and their mobile genetic elements (MGE). These MGEs could be exchanged between bacteria by horizontal gene transfer and may alter the pathogenic potential since they often carry antibiotic resistance or more in general adaptation-enhancing traits. In this study several bacterial strains isolated in the Concordia research station were examined for their plasmid content. An optimized protocol for extraction of large plasmids showed the present of at least one plasmid in 50% of the strains. For all strains the minimal inhibitory concentration of a range of antibiotics was determined indicating resistance to

Midodrine prevents orthostatic intolerance associated with simulated spaceflight

NASA Technical Reports Server (NTRS)

Ramsdell, C. D.; Mullen, T. J.; Sundby, G. H.; Rostoft, S.; Sheynberg, N.; Aljuri, N.; Maa, M.; Mukkamala, R.; Sherman, D.; Toska, K.;

Midodrine prevents orthostatic intolerance associated with simulated spaceflight.

PubMed

Ramsdell, C D; Mullen, T J; Sundby, G H; Rostoft, S; Sheynberg, N; Aljuri, N; Maa, M; Mukkamala, R; Sherman, D; Toska, K; Yelle, J; Bloomfield, D; Williams, G H; Cohen, R J

2001-06-01

Many astronauts after being weightless in space become hypotensive and presyncopal when they assume an upright position. This phenomenon, known as orthostatic intolerance, may interfere with astronaut function during reentry and after spaceflight and may limit the ability of an astronaut to exit a landed spacecraft unaided during an emergency. Orthostatic intolerance is more pronounced after long-term spaceflight and is a major concern with respect to the extended flights expected aboard the International Space Station and for interplanetary exploration class missions, such as a human mission to Mars. Fully effective countermeasures to this problem have not yet been developed. To test the hypothesis that alpha-adrenergic stimulation might provide an effective countermeasure, we conducted a 16-day head-down-tilt bed-rest study (an analog of weightlessness) using normal human volunteers and administered the alpha(1)-agonist drug midodrine at the end of the bed-rest period. Midodrine was found to significantly ameliorate excessive decreases in blood pressure and presyncope during a provocative tilt test. We conclude that midodrine may be an effective countermeasure for the prevention of orthostatic intolerance following spaceflight.

Transcriptomics, NF-κB Pathway, and Their Potential Spaceflight-Related Health Consequences

PubMed Central

Zhang, Ye; Moreno-Villanueva, Maria; Krieger, Stephanie; Ramesh, Govindarajan T.; Neelam, Srujana; Wu, Honglu

2017-01-01

In space, living organisms are exposed to multiple stress factors including microgravity and space radiation. For humans, these harmful environmental factors have been known to cause negative health impacts such as bone loss and immune dysfunction. Understanding the mechanisms by which spaceflight impacts human health at the molecular level is critical not only for accurately assessing the risks associated with spaceflight, but also for developing effective countermeasures. Over the years, a number of studies have been conducted under real or simulated space conditions. RNA and protein levels in cellular and animal models have been targeted in order to identify pathways affected by spaceflight. Of the many pathways responsive to the space environment, the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) network appears to commonly be affected across many different cell types under the true or simulated spaceflight conditions. NF-κB is of particular interest, as it is associated with many of the spaceflight-related health consequences. This review intends to summarize the transcriptomics studies that identified NF-κB as a responsive pathway to ground-based simulated microgravity or the true spaceflight condition. These studies were carried out using either human cell or animal models. In addition, the review summarizes the studies that focused specifically on NF-κB pathway in specific cell types or organ tissues as related to the known spaceflight-related health risks including immune dysfunction, bone loss, muscle atrophy, central nerve system (CNS) dysfunction, and risks associated with space radiation. Whether the NF-κB pathway is activated or inhibited in space is dependent on the cell type, but the potential health impact appeared to be always negative. It is argued that more studies on NF-κB should be conducted to fully understand this particular pathway for the benefit of crew health in space. PMID:28561779

Transcriptomics, NF-κB Pathway, and Their Potential Spaceflight-Related Health Consequences.

PubMed

Zhang, Ye; Moreno-Villanueva, Maria; Krieger, Stephanie; Ramesh, Govindarajan T; Neelam, Srujana; Wu, Honglu

2017-05-31

In space, living organisms are exposed to multiple stress factors including microgravity and space radiation. For humans, these harmful environmental factors have been known to cause negative health impacts such as bone loss and immune dysfunction. Understanding the mechanisms by which spaceflight impacts human health at the molecular level is critical not only for accurately assessing the risks associated with spaceflight, but also for developing effective countermeasures. Over the years, a number of studies have been conducted under real or simulated space conditions. RNA and protein levels in cellular and animal models have been targeted in order to identify pathways affected by spaceflight. Of the many pathways responsive to the space environment, the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) network appears to commonly be affected across many different cell types under the true or simulated spaceflight conditions. NF-κB is of particular interest, as it is associated with many of the spaceflight-related health consequences. This review intends to summarize the transcriptomics studies that identified NF-κB as a responsive pathway to ground-based simulated microgravity or the true spaceflight condition. These studies were carried out using either human cell or animal models. In addition, the review summarizes the studies that focused specifically on NF-κB pathway in specific cell types or organ tissues as related to the known spaceflight-related health risks including immune dysfunction, bone loss, muscle atrophy, central nerve system (CNS) dysfunction, and risks associated with space radiation. Whether the NF-κB pathway is activated or inhibited in space is dependent on the cell type, but the potential health impact appeared to be always negative. It is argued that more studies on NF-κB should be conducted to fully understand this particular pathway for the benefit of crew health in space.

Changes in the immune system during and after spaceflight

NASA Technical Reports Server (NTRS)

Taylor, G. R.; Konstantinova, I.; Sonnenfeld, G.; Jennings, R.

1997-01-01

The results of immunological analyses before, during and after spaceflight, have established the fact that spaceflight can result in a blunting of the immune mechanisms of human crew members and animal test species. There is some evidence that the immune function changes in short-term flights resemble those occurring after acute stress, while the changes during long-term flights resemble those caused by chronic stress. In addition, this blunting of the immune function occurs concomitant with a relative increase in potentially infectious microorganisms in the space cabin environment. This combination of events results in an increased probability of inflight infectious events. The realization of this probability has been shown to be partially negated by the judicious use of a preflight health stabilization program and other operational countermeasures. The continuation of these countermeasures, as well as microbial and immunological monitoring, are recommended for continued spaceflight safety.

The Effect of Spaceflight on the Ultrastructure of the Cerebellum

NASA Technical Reports Server (NTRS)

Holstein, Gay R.; Martinelli, Giorgio P.

2003-01-01

In weightlessness, astronauts and cosmonauts may experience postural illusions as well as motion sickness symptoms known as the space adaptation syndrome. Upon return to Earth, they have irregularities in posture and balance. The adaptation to microgravity and subsequent re-adaptation to Earth occurs over several days. At the cellular level, a process called neuronal plasticity may mediate this adaptation. The term plasticity refers to the flexibility and modifiability in the architecture and functions of the nervous system. In fact, plastic changes are thought to underlie not just behavioral adaptation, but also the more generalized phenomena of learning and memory. The goal of this experiment was to identify some of the structural alterations that occur in the rat brain during the sensory and motor adaptation to microgravity. One brain region where plasticity has been studied extensively is the cerebellar cortex-a structure thought to be critical for motor control, coordination, the timing of movements, and, most relevant to the present experiment, motor learning. Also, there are direct as well as indirect connections between projections from the gravity-sensing otolith organs and several subregions of the cerebellum. We tested the hypothesis that alterations in the ultrastructural (the structure within the cell) architecture of rat cerebellar cortex occur during the early period of adaptation to microgravity, as the cerebellum adapts to the absence of the usual gravitational inputs. The results show ultrastructural evidence for neuronal plasticity in the central nervous system of adult rats after 24 hours of spaceflight. Qualitative studies conducted on tissue from the cerebellar cortex (specifically, the nodulus of the cerebellum) indicate that ultrastructural signs of plasticity are present in the cerebellar zones that receive input from the gravity-sensing organs in the inner ear (the otoliths). These changes are not observed in this region in cagematched

Effects of spaceflight on rat humerus geometry, biomechanics, and biochemistry.

PubMed

Vailas, A C; Zernicke, R F; Grindeland, R E; Kaplansky, A; Durnova, G N; Li, K C; Martinez, D A

1990-01-01

The effects of a 12.5-day spaceflight (Cosmos 1887 biosatellite) on the geometric, biomechanical, and biochemical characteristics of humeri of male specific pathogen-free rats were examined. Humeri of age-matched basal control, synchronous control, and vivarium control rats were contrasted with the flight bones to examine the influence of growth and space environment on bone development. Lack of humerus longitudinal growth occurred during the 12.5 days in spaceflight. In addition, the normal mid-diaphysial periosteal appositional growth was affected; compared with their controls, the spaceflight humeri had less cortical cross-sectional area, smaller periosteal circumferences, smaller anterior-posterior periosteal diameters, and smaller second moments of area with respect to the bending and nonbending axes. The flexural rigidity of the flight humeri was comparable to that of the younger basal control rats and significantly less than that of the synchronous and vivarium controls; the elastic moduli of all four groups, nonetheless, were not significantly different. Generally, the matrix biochemistry of the mid-diaphysial cross sections showed no differences among groups. Thus, the spaceflight differences in humeral mechanical strength and flexural rigidity were probably a result of the differences in humeral geometry rather than material properties.

Effects of spaceflight on rat humerus geometry, biomechanics, and biochemistry

NASA Technical Reports Server (NTRS)

Vailas, A. C.; Zernicke, R. F.; Grindeland, R. E.; Kaplansky, A.; Durnova, G. N.; Li, K. C.; Martinez, D. A.

1990-01-01

The effects of a 12.5-day spaceflight (Cosmos 1887 biosatellite) on the geometric, biomechanical, and biochemical characteristics of humeri of male specific pathogen-free rats were examined. Humeri of age-matched basal control, synchronous control, and vivarium control rats were contrasted with the flight bones to examine the influence of growth and space environment on bone development. Lack of humerus longitudinal growth occurred during the 12.5 days in spaceflight. In addition, the normal mid-diaphysial periosteal appositional growth was affected; compared with their controls, the spaceflight humeri had less cortical cross-sectional area, smaller periosteal circumferences, smaller anterior-posterior periosteal diameters, and smaller second moments of area with respect to the bending and nonbending axes. The flexural rigidity of the flight humeri was comparable to that of the younger basal control rats and significantly less than that of the synchronous and vivarium controls; the elastic moduli of all four groups, nonetheless, were not significantly different. Generally, the matrix biochemistry of the mid-diaphysial cross sections showed no differences among groups. Thus, the spaceflight differences in humeral mechanical strength and flexural rigidity were probably a result of the differences in humeral geometry rather than material properties.

Genetic and metabolic signals during acute enteric bacterial infection alter the microbiota and drive progression to chronic inflammatory disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamdar, Karishma; Khakpour, Samira; Chen, Jingyu

Chronic inflammatory disorders are thought to arise due to an interplay between predisposing host genetics and environmental factors. For example, the onset of inflammatory bowel disease is associated with enteric proteobacterial infection, yet the mechanistic basis for this association is unclear. We have shown previously that genetic defiency in TLR1 promotes acute enteric infection by the proteobacteria Yersinia enterocolitica. Examining that model further, we uncovered an altered cellular immune response that promotes the recruitment of neutrophils which in turn increases metabolism of the respiratory electron acceptor tetrathionate by Yersinia. These events drive permanent alterations in anti-commensal immunity, microbiota composition, andmore » chronic inflammation, which persist long after Yersinia clearence. Deletion of the bacterial genes involved in tetrathionate respiration or treatment using targeted probiotics could prevent microbiota alterations and inflammation. Thus, acute infection can drive long term immune and microbiota alterations leading to chronic inflammatory disease in genetically predisposed individuals.« less

Transgene expression patterns indicate that spaceflight affects stress signal perception and transduction in arabidopsis.

PubMed

Paul, A L; Daugherty, C J; Bihn, E A; Chapman, D K; Norwood, K L; Ferl, R J

2001-06-01

The use of plants as integral components of life support systems remains a cornerstone of strategies for long-term human habitation of space and extraterrestrial colonization. Spaceflight experiments over the past few decades have refined the hardware required to grow plants in low-earth orbit and have illuminated fundamental issues regarding spaceflight effects on plant growth and development. Potential incipient hypoxia, resulting from the lack of convection-driven gas movement, has emerged as a possible major impact of microgravity. We developed transgenic Arabidopsis containing the alcohol dehydrogenase (Adh) gene promoter linked to the beta-glucuronidase (GUS) reporter gene to address specifically the possibility that spaceflight induces the plant hypoxia response and to assess whether any spaceflight response was similar to control terrestrial hypoxia-induced gene expression patterns. The staining patterns resulting from a 5-d mission on the orbiter Columbia during mission STS-93 indicate that the Adh/GUS reporter gene was activated in roots during the flight. However, the patterns of expression were not identical to terrestrial control inductions. Moreover, although terrestrial hypoxia induces Adh/GUS expression in the shoot apex, no apex staining was observed in the spaceflight plants. This indicates that either the normal hypoxia response signaling is impaired in spaceflight or that spaceflight inappropriately induces Adh/GUS activity for reasons other than hypoxia.

Transgene expression patterns indicate that spaceflight affects stress signal perception and transduction in arabidopsis

NASA Technical Reports Server (NTRS)

Paul, A. L.; Daugherty, C. J.; Bihn, E. A.; Chapman, D. K.; Norwood, K. L.; Ferl, R. J.

2001-01-01

The use of plants as integral components of life support systems remains a cornerstone of strategies for long-term human habitation of space and extraterrestrial colonization. Spaceflight experiments over the past few decades have refined the hardware required to grow plants in low-earth orbit and have illuminated fundamental issues regarding spaceflight effects on plant growth and development. Potential incipient hypoxia, resulting from the lack of convection-driven gas movement, has emerged as a possible major impact of microgravity. We developed transgenic Arabidopsis containing the alcohol dehydrogenase (Adh) gene promoter linked to the beta-glucuronidase (GUS) reporter gene to address specifically the possibility that spaceflight induces the plant hypoxia response and to assess whether any spaceflight response was similar to control terrestrial hypoxia-induced gene expression patterns. The staining patterns resulting from a 5-d mission on the orbiter Columbia during mission STS-93 indicate that the Adh/GUS reporter gene was activated in roots during the flight. However, the patterns of expression were not identical to terrestrial control inductions. Moreover, although terrestrial hypoxia induces Adh/GUS expression in the shoot apex, no apex staining was observed in the spaceflight plants. This indicates that either the normal hypoxia response signaling is impaired in spaceflight or that spaceflight inappropriately induces Adh/GUS activity for reasons other than hypoxia.

Changes in symbiotic and associative interrelations in a higher plant-bacterial system during space flight

NASA Astrophysics Data System (ADS)

Kordyum, V. A.; Man'ko, V. G.; Popova, A. F.; Shcherbak, O. H.; Mashinsky, A. L.; Nguen-Hgue-Thyok

The miniature cenosis consisting of the water fern Azolla with its associated symbiotic nitrogen-fixing cyanobacterium Anabaena and the concomitant bacteria was investigated. Ecological closure was shown to produce sharp quantitative and qualitative changes in the number and type of concomitant bacteria. Changes in the distribution of bacterial types grown on beef-extract broth after space flight were recorded. Anabaena azollae underwent the most significant changes under spaceflight conditions. Its cell number per Azolla biomass unit increased substantially. Thus closure of cenosis resulted in a weakening of control over microbial development by Azolla. This tendency was augmented by spaceflight factors. Reduction in control exerted by macro-organisms over development of associated micro-organisms must be taken into account in constructing closed ecological systems in the state of weightlessness.

ISS Overview and the Future of Spaceflight

NASA Technical Reports Server (NTRS)

Lutomski, Michael

2004-01-01

This viewgraph presentation reviews the International Space Station and the future of spaceflight. Pictures of robotics, planetary exploration, astrobiology, space tourism, and space commercialization are all shown.

Biological responses of Habrobracon to spaceflight.

PubMed

von Borstel, R C; Smith, R H; Whiting, A R; Grosch, D S

1970-01-01

Since the interaction of the parasitic wasp Habrobracon with the space environment could not be prejudged, we decided to test approximately 30 different parameters of a genetic, mutational, biochemical, behavioral, and physiological character in the one spaceflight we had at our disposal. These parameters were examined at six different exposures of gamma-radiation (including 0 dose) in flight, resulting in about 180 different endpoints in all. The most profound effects of spaceflight in conjunction with radiation were decreased hatchability and enhanced fecundity of eggs exposed to spaceflight at different stages of oogenesis. The interpretation we favor is that these two endpoints are reflections of chromosomal non-disjunction in the former case and inhibition of cell division in the latter. Our most comprehensive study of mutagenesis was on sperm, where dominant lethality, recessive lethality, translocations, and visible mutations were assayed; the only effect found was a threefold enhancement of the recessive lethal mutation frequency in the non-irradiated sperm in the orbited Habrobracon males. Behavioral and biochemical differences were found. Mating activity of orbited males was severely disrupted and xanthine dehydrogenase activity was sharply decreased in the irradiated flight animals, an unexpected observation. Postflight experiments were like the ground-based control experiments in all aspects but one. Under conditions of vibration similar to those encountered during the launch and re-entry, the mutation frequency in the sperm increased by a factor of three over that of the non-vibrated control.

Altered cell function in microgravity

NASA Technical Reports Server (NTRS)

Hughes-Fulford, Millie

1991-01-01

The paper overviews published results from investigations of changes in basic biological parameters taking place as a result of spaceflight exposure. These include changes in the rates of the DNA, mRNA, and protein biosyntheses; changes in the growth rate of an organism; and alterations in the cytoskeleton structure, differentiation, hormone accumulation, and collagen matrix secretion. These results, obtained both in complex biological organisms and on cultured cells, suggest that a basic cellular function is influenced and changed by microgravity. Many of the above mentioned changes are also found to take place in aging cells.

Growth in spaceflight hardware results in alterations to the transcriptome and proteome

NASA Astrophysics Data System (ADS)

Basu, Proma; Kruse, Colin P. S.; Luesse, Darron R.; Wyatt, Sarah E.

2017-11-01

The Biological Research in Canisters (BRIC) hardware has been used to house many biology experiments on both the Space Transport System (STS, commonly known as the space shuttle) and the International Space Station (ISS). However, microscopic examination of Arabidopsis seedlings by Johnson et al. (2015) indicated the hardware itself may affect cell morphology. The experiment herein was designed to assess the effects of the BRIC-Petri Dish Fixation Units (BRIC-PDFU) hardware on the transcriptome and proteome of Arabidopsis seedlings. To our knowledge, this is the first transcriptomic and proteomic comparison of Arabidopsis seedlings grown with and without hardware. Arabidopsis thaliana wild-type Columbia (Col-0) seeds were sterilized and bulk plated on forty-four 60 mm Petri plates, of which 22 were integrated into the BRIC-PDFU hardware and 22 were maintained in closed containers at Ohio University. Seedlings were grown for approximately 3 days, fixed with RNAlater® and stored at -80 °C prior to RNA and protein extraction, with proteins separated into membrane and soluble fractions prior to analysis. The RNAseq analysis identified 1651 differentially expressed genes; MS/MS analysis identified 598 soluble and 589 membrane proteins differentially abundant both at p < .05. Fold enrichment analysis of gene ontology terms related to differentially expressed transcripts and proteins highlighted a variety of stress responses. Some of these genes and proteins have been previously identified in spaceflight experiments, indicating that these genes and proteins may be perturbed by both conditions.

High-grain diets altered rumen fermentation and epithelial bacterial community and resulted in rumen epithelial injuries of goats.

PubMed

Zhang, Ruiyang; Ye, Huimin; Liu, Junhua; Mao, Shengyong

2017-09-01

This study evaluated the effects of high-grain diets on the rumen fermentation, epithelial bacterial community, morphology of rumen epithelium, and local inflammation of goats during high-grain feeding. Twelve 8-month-old goats were randomly assigned to two different diets, a hay diet or a high-grain diet (65% grain, HG). At the end of 7 weeks of treatment, samples of rumen content and rumen epithelium were collected. Rumen pH was lower (P < 0.05), but the levels of volatile fatty acids and lipopolysaccharides were higher (P < 0.05) in the HG group than those in the hay group. The principal coordinate analysis indicated that HG diets altered the rumen epithelial bacterial community, with an increase in the proportion of genus Prevotella and a decrease in the relative abundance of the genera Shuttleworthia and Fibrobacteres. PICRUSt analysis suggested that the HG-fed group had a higher (P < 0.05) relative abundance of gene families related to energy metabolism; folding, sorting, and degradation; translation; metabolic diseases; and immune system. Furthermore, HG feeding resulted in the rumen epithelial injury and upregulated (P < 0.05) the gene expressions of IL-1β and IL-6, and the upregulations were closely related to the rumen pH, LPS level, and rumen epithelial bacteria abundance. In conclusion, our results indicated that the alterations in the rumen environment and epithelial bacterial community which were induced by HG feeding may result in the damage and local inflammation in the rumen epithelium, warranting further study of rumen microbial-host interactions in the HG feeding model.

Bridging the Gap: Use of Spaceflight Technologies for Earth-Based Problems

NASA Technical Reports Server (NTRS)

Brinley, Alaina; Vidlak, Carissa; Davis, Jeffrey R.

2012-01-01

Spaceflight is colloquially deemed, the final frontier, or the last area which humans have not yet explored in great depth. While this is true, there are still many regions on Earth that remain isolated from the urban, socially and electronically connected world. Because travelling to space requires a great deal of foresight, engineers are required to think creatively in order to invent technologies that are durable enough to withstand the rigors of the unique and often treacherous environment of outer space. The innovations that are a result of spaceflight designs can often be applied to life on Earth, particularly in the rural, isolated communities found throughout the world. The NASA Human Health and Performance Center (NHHPC) is a collaborative, virtual forum that connects businesses, non-profit organizations, academia, and government agencies to allow for better distribution of ideas and technology between these entities (http://www.nasa.gov/offices/NHHPC). There are many technologies that have been developed for spaceflight that can be readily applied to rural communities on Earth. For example, water filtration systems designed for spaceflight must be robust and easily repaired; therefore, a system with these qualifications may be used in rural areas on Earth. This particular initiative seeks to connect established, non-profit organizations working in isolated communities throughout the world with NASA technologies devised for spaceflight. These technologies could include water purification systems, solar power generators, or telemedicine techniques. Applying innovative, spaceflight technologies to isolated communities on Earth provides greater benefits from the same research dollars, thus fulfilling the Space Life Science motto at Johnson Space Center: Exploring Space and Enhancing Life. This paper will discuss this NHHPC global outreach initiative and give examples based on the recent work of the organization.

An emergency medical planning guide for commercial spaceflight events.

PubMed

Law, Jennifer; Vanderploeg, James

2012-09-01

Commercial spaceflight events transporting paying passengers into space will begin to take place at various spaceports around the country within the next few years. Many spaceports are located in remote areas that are far from major hospitals and trauma centers. Spaceport medical directors should develop emergency medical plans (EMPs) to prepare for potential medical contingencies that may occur during commercial spaceflight events. The aim of this article is to guide spaceport medical directors in emergency medical planning for commercial spaceflight events. This guide is based on our experience and a recently developed EMP for Spaceport America which incorporated a literature review of mass gathering medicine, existing planning guides for mass gathering events, and EMPs for analogous aerospace events. We propose a multipronged approach to emergency medical planning, consisting of event planning, medical reconnaissance, medical personnel, protocols, physical facility and hardware, and documentation. Medical directors should use this guide to develop an emergency medical plan tailored to the resources and constraints specific to their events.

Synthetic Biology and Human Health: Potential Applications for Spaceflight

NASA Technical Reports Server (NTRS)

Karouia, Fathi; Carr, Christopher; Cai, Yizhi; Chen, Y.; Grenon, Marlene; Larios-Sanz, Maia; Jones, Jeffrey A.; Santos, Orlando

2011-01-01

Human space travelers experience a unique environment that affects homeostasis and physiologic adaptation. Spaceflight-related changes have been reported in the musculo-skeletal, cardiovascular, neurovestibular, endocrine, and immune systems. The spacecraft environment further subjects the traveler to noise and gravitational forces, as well as airborne chemical, microbiological contaminants, and radiation exposure. As humans prepare for longer duration missions effective countermeasures must be developed, verified, and implemented to ensure mission success. Over the past ten years, synthetic biology has opened new avenues for research and development in areas such as biological control, biomaterials, sustainable energy production, bioremediation, and biomedical therapies. The latter in particular is of great interest to the implementation of long-duration human spaceflight capabilities. This article discusses the effects of spaceflight on humans, and reviews current capabilities and potential needs associated with the health of the astronauts where synthetic biology could play an important role in the pursuit of space exploration.

Altered Gravity Induces Oxidative Stress in Drosophila Melanogaster

NASA Technical Reports Server (NTRS)

Bhattacharya, Sharmila; Hosamani, Ravikumar

2015-01-01

Altered gravity environments can induce increased oxidative stress in biological systems. Microarray data from our previous spaceflight experiment (FIT experiment on STS-121) indicated significant changes in the expression of oxidative stress genes in adult fruit flies after spaceflight. Currently, our lab is focused on elucidating the role of hypergravity-induced oxidative stress and its impact on the nervous system in Drosophila melanogaster. Biochemical, molecular, and genetic approaches were combined to study this effect on the ground. Adult flies (2-3 days old) exposed to acute hypergravity (3g, for 1 hour and 2 hours) showed significantly elevated levels of Reactive Oxygen Species (ROS) in fly brains compared to control samples. This data was supported by significant changes in mRNA expression of specific oxidative stress and antioxidant defense related genes. As anticipated, a stress-resistant mutant line, Indy302, was less vulnerable to hypergravity-induced oxidative stress compared to wild-type flies. Survival curves were generated to study the combined effect of hypergravity and pro-oxidant treatment. Interestingly, many of the oxidative stress changes that were measured in flies showed sex specific differences. Collectively, our data demonstrate that altered gravity significantly induces oxidative stress in Drosophila, and that one of the organs where this effect is evident is the brain.

Tolerance of centrifuge-simulated suborbital spaceflight in subjects with implanted insulin pumps.

PubMed

Levin, Dana R; Blue, Rebecca S; Castleberry, Tarah L; Vanderploeg, James M

2015-04-01

With commercial spaceflight comes the possibility of spaceflight participants (SFPs) with significant medical conditions. Those with previously untested medical conditions, such as diabetes mellitus (DM) and the use of indwelling medical devices, represent a unique challenge. It is unclear how SFPs with such devices will react to the stresses of spaceflight. This case report describes two subjects with Type I DM using insulin pumps who underwent simulated dynamic phases of spaceflight via centrifuge G force exposure. Two Type I diabetic subjects with indwelling Humalog insulin pumps, a 23-yr-old man averaging 50 u of Humalog daily and a 27-yr-old man averaging 60 u of Humalog daily, underwent seven centrifuge runs over 48 h. Day 1 consisted of two +Gz runs (peak = +3.5 Gz, run 2) and two +Gx runs (peak = +6.0 Gx, run 4). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +Gx and +Gz). Data collected included blood pressure, electrocardiogram, pulse oximetry, neurovestibular evaluation, and questionnaires regarding motion sickness, disorientation, greyout, and other symptoms. Neither subject experienced adverse clinical responses to the centrifuge exposure. Both maintained blood glucose levels between 110-206 mg · dl(-1). Potential risks to SFPs with insulin pump dependent DM include hypo/hyperglycemia, pump damage, neurovestibular dysfunction, skin breakdown, and abnormal stress responses. A search of prior literature did not reveal any previous studies of individuals with DM on insulin pumps exposed to prolonged accelerations. These cases suggest that individuals with conditions dependent on continuous medication delivery might tolerate the accelerations anticipated for commercial spaceflight.

Stability of the rhizosphere and endophytic bacterial communities associated with Arabidopsis thaliana (L.) Heynh under impact of cosmic factors

NASA Astrophysics Data System (ADS)

Kordium, V. A.; Adamchuk-Chala, N. I.; Moshinec, H. V.

The orbital experiment will involve a growing of Arabidopsis plant seed to seed in the presence of a plant probiotic bacteria consortium introduced into the system The purpose of experiment is to characterize microbial community associated with Arabidopsis thaliana and determine how consortium of introduced bacteria along with the endemic plant-associated bacteria influences the plant development reproductive system and seed formation in spaceflight conditions The first study will be an examination of the survival of model bacteria in on the inoculated plant The second complex study is to examine the plant traits in particular the ultrastructure of root statocytes in order to determine whether the plant development proceeds normally under microgravity conditions on background of introduced bacteria and to assess the structural changes occurring in the cotyledons generative organs and seeds The third set of observations will concern studies of the structure of microbial community associated with Arabidopsis plants with traditional and molecular tools The fourth part of the work will be an examination of mobile genetic elements that can play a role in adaptation of bacteria to the spaceflight conditions however they may affect the stability of bacterial endo- and rhizosphere communities The final part of the proposal initiates the study of possible risk of the bacterial consortium use for a plant inoculation in spaceflight conditions An evaluation of this risk will be performed via examination of expression of the Klebsiella

Spaceflight impairs antigen-specific tolerance induction in vivo and increases inflammatory cytokines.

PubMed

Chang, Tammy T; Spurlock, Sandra M; Candelario, Tara Lynne T; Grenon, S Marlene; Hughes-Fulford, Millie

2015-10-01

The health risks of a dysregulated immune response during spaceflight are important to understand as plans emerge for humans to embark on long-term space travel to Mars. In this first-of-its-kind study, we used adoptive transfer of T-cell receptor transgenic OT-II CD4 T cells to track an in vivo antigen-specific immune response that was induced during the course of spaceflight. Experimental mice destined for spaceflight and mice that remained on the ground received transferred OT-II cells and cognate peptide stimulation with ovalbumin (OVA) 323-339 plus the inflammatory adjuvant, monophosphoryl lipid A. Control mice in both flight and ground cohorts received monophosphoryl lipid A alone without additional OVA stimulation. Numbers of OT-II cells in flight mice treated with OVA were significantly increased by 2-fold compared with ground mice treated with OVA, suggesting that tolerance induction was impaired by spaceflight. Production of proinflammatory cytokines were significantly increased in flight compared with ground mice, including a 5-fold increase in IFN-γ and a 10-fold increase in IL-17. This study is the first to show that immune tolerance may be impaired in spaceflight, leading to excessive inflammatory responses. © FASEB.

Hydrocortisone and ACTH levels in manned spaceflight

NASA Technical Reports Server (NTRS)

Leach, C. S.; Campbell, B. O.

1974-01-01

The plasma hydrocortisone, plasma ACTH, and urinary hydrocortisone values were recorded for each man of the crews of Apollo flights eight through fifteen, 30, 14, and 5 days before flight, immediately after spaceflight recovery, and on future days until the return of most variables to preflight values. The plasma and urinary preflight hydrocortisone values were significantly higher than the postflight values. This result is discussed in terms of three possible explanations: (1) the adrenal-cortical function is suppressed during spaceflight; (2) the activity in flight may amount to stressful exercise, which tests have shown can cause a decrease in plasma adrenocortical hormones; and (3) the in-flight work-rest cycles may be such as to affect the circadian periodicity of the pituitary-adrenal function.

Oxidant damage during and after spaceflight

NASA Technical Reports Server (NTRS)

Stein, T. P.; Leskiw, M. J.

2000-01-01

The objectives of this study were to assess oxidant damage during and after spaceflight and to compare the results against bed rest with 6 degrees head-down tilt. We measured the urinary excretion of the F(2) isoprostane, 8-iso-prostaglandin (PG) F(2alpha), and 8-oxo-7,8-dihydro-2 deoxyguanosine (8-OH DG) before, during, and after long-duration spaceflight (4-9 mo) on the Russian space station MIR, short-duration spaceflight on the shuttle, and 17 days of bed rest. Sample collections on MIR were obtained between 88 and 186 days in orbit. 8-iso-PGF(2alpha) and 8-OH DG are markers for oxidative damage to membrane lipids and DNA, respectively. Data are mean +/- SE. On MIR, isoprostane levels were decreased inflight (96. 9 +/- 11.6 vs. 76.7 +/- 14.9 ng. kg(-1). day(-1), P < 0.05, n = 6) due to decreased dietary intake secondary to impaired thermoregulation. Isoprostane excretion was increased postflight (245.7 +/- 55.8 ng. kg(-1). day(-1), P < 0.01). 8-OH DG excretion was unchanged with spaceflight and increased postflight (269 +/- 84 vs 442 +/- 180 ng. kg(-1). day(-1), P < 0.05). On the shuttle, 8-OH DG excretion was unchanged in- and postflight, but 8-iso-PGF(2alpha) excretion was decreased inflight (15.6 +/- 4.3 vs 8.0 +/- 2.7 ng. kg(-1). day(-1), P < 0.05). No changes were found with bed rest, but 8-iso-PGF(2alpha) was increased during the recovery phase (48.9 +/- 23.0 vs 65.4 +/- 28.3 ng. kg(-1). day(-1), P < 0.05). The changes in isoprostane production were attributed to decreased production of oxygen radicals from the electron transport chain due to the reduced energy intake inflight. The postflight increases in the excretion of the products of oxidative damage were attributed to a combination of an increase in metabolic activity and the loss of some host antioxidant defenses inflight. We conclude that 1) oxidative damage was decreased inflight, and 2) oxidative damage was increased postflight.

Clinical Herpes Zoster in Antarctica as a Model for Spaceflight.

PubMed

Reyes, David P; Brinley, Alaina A; Blue, Rebecca S; Gruschkus, Stephen K; Allen, Andrew T; Parazynski, Scott E

2017-08-01

Antarctica is a useful analog for spaceflight, as both environments are remote, isolated, and with limited resources. While previous studies have demonstrated increased asymptomatic viral shedding in both the Antarctic and spaceflight environments, clinical manifestations of reactivated viral disease have been less frequently identified. We sought to identify the incidence of clinical herpes zoster from viral reactivation in the Antarctic winter-over population. Medical records from the 2014 winter season were reviewed for the incidence of zoster in U.S. Antarctic personnel and then compared to the age-matched U.S. Five cases of clinical herpes zoster occurred in the Antarctic Station population of 204 persons, for an incidence of 33.3 per 1000 person-years vs. 3.2 per 1000 person-years in the general population. Four cases were in persons under age 40, yielding an incidence of 106.7 per 1000 person-years in persons ages 30-39 compared to an incidence of 2.0 per 1000 person-years in the same U.S. age group. Immune suppression due to the stressful Antarctic environment may have contributed to the increased incidence of herpes zoster in U.S. Antarctic personnel during the winter of 2014. Working and living in isolated, confined, and extreme environments can cause immune suppression, reactivating latent viruses and increasing viral shedding and symptomatic disease. Such changes have been observed in other austere environments, including spaceflight, suggesting that clinical manifestations of viral reactivation may be seen in future spaceflight.Reyes DP, Brinley AA, Blue RS, Gruschkus SK, Allen AT, Parazynski SE. Clinical herpes zoster in Antarctica as a model for spaceflight. Aerosp Med Hum Perform. 2017; 88(8):784-788.

Bacterial meningitis.

PubMed

Heckenberg, Sebastiaan G B; Brouwer, Matthijs C; van de Beek, Diederik

2014-01-01

Bacterial meningitis is a neurologic emergency. Vaccination against common pathogens has decreased the burden of disease. Early diagnosis and rapid initiation of empiric antimicrobial and adjunctive therapy are vital. Therapy should be initiated as soon as blood cultures have been obtained, preceding any imaging studies. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, and an altered level of consciousness but signs may be scarce in children, in the elderly, and in meningococcal disease. Host genetic factors are major determinants of susceptibility to meningococcal and pneumococcal disease. Dexamethasone therapy has been implemented as adjunctive treatment of adults with pneumococcal meningitis. Adequate and prompt treatment of bacterial meningitis is critical to outcome. In this chapter we review the epidemiology, pathophysiology, and management of bacterial meningitis. © 2014 Elsevier B.V. All rights reserved.

Heart rate variability and short duration spaceflight: relationship to post-flight orthostatic intolerance

PubMed Central

Blaber, Andrew P; Bondar, Roberta L; Kassam, Mahmood S

2004-01-01

Background Upon return from space many astronauts experience symptoms of orthostatic intolerance. Research has implicated altered autonomic cardiovascular regulation due to spaceflight with further evidence to suggest that there might be pre-flight autonomic indicators of post-flight orthostatic intolerance. We used heart rate variability (HRV) to determine whether autonomic regulation of the heart in astronauts who did or did not experience post-flight orthostatic intolerance was different pre-flight and/or was differentially affected by short duration (8 – 16 days) spaceflight. HRV data from ten-minute stand tests collected from the 29 astronauts 10 days pre-flight, on landing day and three days post-flight were analysed using coarse graining spectral analysis. From the total power (PTOT), the harmonic component was extracted and divided into high (PHI: >0.15 Hz) and low (PLO: = 0.15 Hz) frequency power regions. Given the distribution of autonomic nervous system activity with frequency at the sinus node, PHI/PTOT was used as an indicator of parasympathetic activity; PLO/PTOT as an indicator of sympathetic activity; and, PLO/PHI as an estimate of sympathovagal balance. Results Twenty-one astronauts were classified as finishers, and eight as non-finishers, based on their ability to remain standing for 10 minutes on landing day. Pre-flight, non-finishers had a higher supine PHI/PTOT than finishers. Supine PHI/PTOT was the same pre-flight and on landing day in the finishers; whereas, in the non-finishers it was reduced. The ratio PLO/PHI was lower in non-finishers compared to finishers and was unaffected by spaceflight. Pre-flight, both finishers and non-finishers had similar supine values of PLO/PTOT, which increased from supine to stand. Following spaceflight, only the finishers had an increase in PLO/PTOT from supine to stand. Conclusions Both finishers and non-finishers had an increase in sympathetic activity with stand on pre-flight, yet only finishers

The Human Sympathetic Nervous System Response to Spaceflight

NASA Technical Reports Server (NTRS)

Ertl, Andrew C.; Diedrich, Andre; Paranjape, Sachin Y.; Biaggioni, Italo; Robertson, Rose Marie; Lane, Lynda D.; Shiavi, Richard; Robertson, David

2003-01-01

The sympathetic nervous system is an important part of the autonomic (or automatic) nervous system. When an individual stands up, the sympathetic nervous system speeds the heart and constricts blood vessels to prevent a drop in blood pressure. A significant number of astronauts experience a drop in blood pressure when standing for prolonged periods after they return from spaceflight. Difficulty maintaining blood pressure with standing is also a daily problem for many patients. Indirect evidence available before the Neurolab mission suggested the problem in astronauts while in space might be due partially to reduced sympathetic nervous system activity. The purpose of this experiment was to identify whether sympathetic activity was reduced during spaceflight. Sympathetic nervous system activity can be determined in part by measuring heart rate, nerve activity going to blood vessels, and the release of the hormone norepinephrine into the blood. Norepinephrine is a neurotransmitter discharged from active sympathetic nerve terminals, so its rate of release can serve as a marker of sympathetic nervous system action. In addition to standard cardiovascular measurements (heart rate, blood pressure), we determined sympathetic nerve activity as well as norepinephrine release and clearance on four crewmembers on the Neurolab mission. Contrary to our expectation, the results demonstrated that the astronauts had mildly elevated resting sympathetic nervous system activity in space. Sympathetic nervous system responses to stresses that simulated the cardiovascular effects of standing (lower body negative pressure) were brisk both during and after spaceflight. We concluded that, in the astronauts tested, the activity and response of the sympathetic nervous system to cardiovascular stresses appeared intact and mildly elevated both during and after spaceflight. These changes returned to normal within a few days.

Gravity in mammalian organ development: differentiation of cultured lung and pancreas rudiments during spaceflight

NASA Technical Reports Server (NTRS)

Spooner, B. S.; Hardman, P.; Paulsen, A.

1994-01-01

Organ culture of embryonic mouse lung and pancreas rudiments has been used to investigate development and differentiation, and to assess the effects of microgravity on culture differentiation, during orbital spaceflight of the shuttle Endeavour (mission STS-54). Lung rudiments continue to grow and branch during spaceflight, an initial result that should allow future detailed study of lung morphogenesis in microgravity. Cultured embryonic pancreas undergoes characteristic exocrine acinar tissue and endocrine islet tissue differentiation during spaceflight, and in ground controls. The rudiments developing in the microgravity environment of spaceflight appear to grow larger than their ground counterparts, and they may have differentiated more rapidly than controls, as judged by exocrine zymogen granule presence.

Longevity of the Human Spaceflight Program

NASA Astrophysics Data System (ADS)

Gott, J. Richard

2007-02-01

The longevity of the human spaceflight program is important to our survival prospects. On May 27, 1993 I proposed a method for estimating future longevity, based on past observed longevity using the Copernican Principle: if your observation point is not special the 95% confidence level prediction of future longevity is between (1/39)th and 39 times the past longevity. The prediction for the future longevity of the human spaceflight program (then 32 years old) was greater than 10 months but less than 1248 years. We have already passed the lower limit. This Copernican formula has been tested a number of times, correctly predicting, among other things, future longevities of Broadway plays and musicals, and the Conservative Government in the United Kingdom. Recently, a study of future longevities of the 313 world leaders in power on May 27, 1993 has been completed. Assuming none still in office serve past age 100, the success rate of the 95% Copernican Formula is currently 94.55% with only one case (out of 313) left to be decided. The human spaceflight program has not been around long and so there is the danger its future will not be long enough to allow us to colonize off the earth. Policy implications are discussed. A smart plan would be to try to establish a self-supporting colony on Mars in the next 45 years. This should not require sending any more tons of material into space in the next 45 years than we have in the last 45 years.

Effects of Spaceflight on Venous and Arterial Compliance

NASA Technical Reports Server (NTRS)

Platts, S. H.; Pibeiro, L. C.; Laurie, S. S.; Lee, S. M. C.; Martin, D. S.; Ploutz-Snyder, R.; Stenger, M. B.

2016-01-01

The visual impairment and intracranial pressure (VIIP) syndrome is a spaceflight-associated medical condition consisting of a constellation of symptoms affecting less than 70% of American astronauts who have flown International Space Station (ISS) missions. VIIP is defined primarily by visual acuity deficits and anatomical changes to eye structures and is hypothesized to be related to elevated intracranial pressure secondary to spaceflight-induced cephalad fluid shifts, although other space flight factors (e.g., diet, environmental factors) may contribute. Loss of visual acuity could be a significant threat to crew health and performance during and after an exploration mission and may have implications for years postflight.

Altered baroreflex control of forearm vascular resistance during simulated microgravity

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Doerr, D. F.; Vernikos, J.

1994-01-01

Reflex peripheral vasoconstriction induced by activation of cardiopulmonary baroreceptors in response to reduced central venous pressure (CVP) is a basic mechanism for elevating systemic vascular resistance and defending arterial blood pressure during orthostatically-induced reductions in cardiac filling and output. The sensitivity of the cardiopulmonary baroreflex response [defined as the slope of the relationship between changes in forearm vascular resistance (FVR) and CVP] and the resultant vasoconstriction are closely and inversely associated with the amount of circulating blood volume. Thus, a high-gain FVR response will be elicited by a hypovolemic state. Exposure to microgravity during spaceflight results in reduced plasma volume. It is therefore reasonable to expect that the FVR response to cardiopulmonary baroreceptor unloading would be accentuated following adaptation to microgravity. Such data could provide better insight about the physiological mechanisms underlying alterations in blood pressure control following spaceflight. We therefore exposed eleven men to 6 degrees head-down bedrest for 7 days and measured specific hemodynamic responses to low levels of the lower body negative pressure to determine if there are alterations in cardiopulmonary baroreceptor stimulus-FVR reflex response relationship during prolonged exposure to an analog of microgravity.

Distance and Size Perception in Astronauts during Long-Duration Spaceflight

PubMed Central

Clément, Gilles; Skinner, Anna; Lathan, Corinna

2013-01-01

Exposure to microgravity during spaceflight is known to elicit orientation illusions, errors in sensory localization, postural imbalance, changes in vestibulo-spinal and vestibulo-ocular reflexes, and space motion sickness. The objective of this experiment was to investigate whether an alteration in cognitive visual-spatial processing, such as the perception of distance and size of objects, is also taking place during prolonged exposure to microgravity. Our results show that astronauts on board the International Space Station exhibit biases in the perception of their environment. Objects’ heights and depths were perceived as taller and shallower, respectively, and distances were generally underestimated in orbit compared to Earth. These changes may occur because the perspective cues for depth are less salient in microgravity or the eye-height scaling of size is different when an observer is not standing on the ground. This finding has operational implications for human space exploration missions. PMID:25369884

In Brief: Web site for human spaceflight review committee

NASA Astrophysics Data System (ADS)

Showstack, Randy

2009-06-01

As part of an independent review of human spaceflight plans and programs, NASA has established a Web site for the Review of U.S. Human Space Flight Plans Committee (http://hsfnasagov). The Web site provides the committee's charter, relevant documents, information about meetings and members, and ways to contact the committee. “The human spaceflight program belongs to everyone. Our committee would hope to benefit from the views of all who would care to contact us,” noted committee chairman Norman Augustine, retired chair and CEO of Lockheed Martin Corporation.

Pharmaceuticals suppress algal growth and microbial respiration and alter bacterial communities in stream biofilms.

PubMed

Rosi-Marshall, Emma J; Kincaid, Dustin W; Bechtold, Heather A; Royer, Todd V; Rojas, Miguel; Kelly, John J

2013-04-01

Pharmaceutical and personal care products are ubiquitous in surface waters but their effects on aquatic biofilms and associated ecosystem properties are not well understood. We measured in situ responses of stream biofilms to six common pharmaceutical compounds (caffeine, cimetidine, ciprofloxacin, diphenhydramine, metformin, ranitidine, and a mixture of each) by deploying pharmaceutical-diffusing substrates in streams in Indiana, Maryland, and New York. Results were consistent across seasons and geographic locations. On average, algal biomass was suppressed by 22%, 4%, 22%, and 18% relative to controls by caffeine, ciprofloxacin, diphenhydramine, and the mixed treatment, respectively. Biofilm respiration was significantly suppressed by caffeine (53%), cimetidine (51%), ciprofloxacin (91%), diphenhydramine (63%), and the mixed treatment (40%). In autumn in New York, photosynthesis was also significantly suppressed by diphenhydramine (99%) and the mixed treatment (88%). Pyrosequencing of 16S rRNA genes was used to examine the effects of caffeine and diphenhydramine on biofilm bacterial community composition at the three sites. Relative to the controls, diphenhydramine exposure significantly altered bacterial community composition and resulted in significant relative increases in Pseudomonas sp. and decreases in Flavobacterium sp. in all three streams. These ubiquitous pharmaceuticals, alone or in combination, influenced stream biofilms, which could have consequences for higher trophic levels and important ecosystem processes.

Growth in spaceflight hardware results in alterations to the transcriptome and proteome.

PubMed

Basu, Proma; Kruse, Colin P S; Luesse, Darron R; Wyatt, Sarah E

2017-11-01

The Biological Research in Canisters (BRIC) hardware has been used to house many biology experiments on both the Space Transport System (STS, commonly known as the space shuttle) and the International Space Station (ISS). However, microscopic examination of Arabidopsis seedlings by Johnson et al. (2015) indicated the hardware itself may affect cell morphology. The experiment herein was designed to assess the effects of the BRIC-Petri Dish Fixation Units (BRIC-PDFU) hardware on the transcriptome and proteome of Arabidopsis seedlings. To our knowledge, this is the first transcriptomic and proteomic comparison of Arabidopsis seedlings grown with and without hardware. Arabidopsis thaliana wild-type Columbia (Col-0) seeds were sterilized and bulk plated on forty-four 60 mm Petri plates, of which 22 were integrated into the BRIC-PDFU hardware and 22 were maintained in closed containers at Ohio University. Seedlings were grown for approximately 3 days, fixed with RNAlater ® and stored at -80 °C prior to RNA and protein extraction, with proteins separated into membrane and soluble fractions prior to analysis. The RNAseq analysis identified 1651 differentially expressed genes; MS/MS analysis identified 598 soluble and 589 membrane proteins differentially abundant both at p < .05. Fold enrichment analysis of gene ontology terms related to differentially expressed transcripts and proteins highlighted a variety of stress responses. Some of these genes and proteins have been previously identified in spaceflight experiments, indicating that these genes and proteins may be perturbed by both conditions. Copyright © 2017 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Transgene Expression Patterns Indicate That Spaceflight Affects Stress Signal Perception and Transduction in Arabidopsis1

PubMed Central

Paul, Anna-Lisa; Daugherty, Christine J.; Bihn, Elizabeth A.; Chapman, David K.; Norwood, Kelly L.L.; Ferl, Robert J.

2001-01-01

The use of plants as integral components of life support systems remains a cornerstone of strategies for long-term human habitation of space and extraterrestrial colonization. Spaceflight experiments over the past few decades have refined the hardware required to grow plants in low-earth orbit and have illuminated fundamental issues regarding spaceflight effects on plant growth and development. Potential incipient hypoxia, resulting from the lack of convection-driven gas movement, has emerged as a possible major impact of microgravity. We developed transgenic Arabidopsis containing the alcohol dehydrogenase (Adh) gene promoter linked to the β-glucuronidase (GUS) reporter gene to address specifically the possibility that spaceflight induces the plant hypoxia response and to assess whether any spaceflight response was similar to control terrestrial hypoxia-induced gene expression patterns. The staining patterns resulting from a 5-d mission on the orbiter Columbia during mission STS-93 indicate that the Adh/GUS reporter gene was activated in roots during the flight. However, the patterns of expression were not identical to terrestrial control inductions. Moreover, although terrestrial hypoxia induces Adh/GUS expression in the shoot apex, no apex staining was observed in the spaceflight plants. This indicates that either the normal hypoxia response signaling is impaired in spaceflight or that spaceflight inappropriately induces Adh/GUS activity for reasons other than hypoxia. PMID:11402191

Changes in toe clearance during treadmill walking after long-duration spaceflight.

PubMed

Miller, Christopher A; Peters, Brian T; Brady, Rachel R; Richards, Jason R; Ploutz-Snyder, Robert J; Mulavara, Ajitkumar P; Bloomberg, Jacob J

2010-10-01

Astronauts exhibit sensorimotor changes upon return from long-duration spaceflight that can result in altered gait kinematics and possibly an increased risk of tripping. Toe trajectory during locomotion is a precise motor control task involving both legs, thus providing a composite metric of locomotor control. The purpose of this study was to determine whether astronauts are at an increased risk of tripping after their return from long-duration spaceflight. This was accomplished by assessing the pre- to postflight changes in toe clearance during treadmill walking. Ten crewmembers walked on a treadmill while performing a visual-acuity task pre- and postflight. In the three subjects on whom landing day data were available, each exhibited a characteristic of increased tripping risk on landing day: either a decreased median toe clearance or an increased interquartile range (a measure of variance). For all crewmembers, toe clearance median and interquartile range were not significantly different from preflight for the other postflight sessions (the earliest being 1 d after landing). A follow-up analysis showed that changes in foot pitch, ankle dorsiflexion, and pelvis roll angles were significant predictors of changes in toe clearance. The landing-day observations indicated an increased risk of tripping, which may pose a hazard during locomotion immediately upon return to Earth, especially in an emergency scenario. However, tripping risk on subsequent days was not different than preflight. The joint angle analysis suggested that the crewmembers tried to reestablish their normal walking pattern postflight, instead of developing a new motor control strategy.

Plant growth strategies are remodeled by spaceflight.

PubMed

Paul, Anna-Lisa; Amalfitano, Claire E; Ferl, Robert J

2012-12-07

Arabidopsis plants were grown on the International Space Station within specialized hardware that combined a plant growth habitat with a camera system that can capture images at regular intervals of growth. The Imaging hardware delivers telemetric data from the ISS, specifically images received in real-time from experiments on orbit, providing science without sample return. Comparable Ground Controls were grown in a sister unit that is maintained in the Orbital Environment Simulator at Kennedy Space Center. One of many types of biological data that can be analyzed in this fashion is root morphology. Arabidopsis seeds were geminated on orbit on nutrient gel Petri plates in a configuration that encouraged growth along the surface of the gel. Photos were taken every six hours for the 15 days of the experiment. In the absence of gravity, but the presence of directional light, spaceflight roots remained strongly negatively phototropic and grew in the opposite direction of the shoot growth; however, cultivars WS and Col-0 displayed two distinct, marked differences in their growth patterns. First, cultivar WS skewed strongly to the right on orbit, while cultivar Col-0 grew with little deviation away from the light source. Second, the Spaceflight environment also impacted the rate of growth in Arabidopsis. The size of the Flight plants (as measured by primary root and hypocotyl length) was uniformly smaller than comparably aged Ground Control plants in both cultivars. Skewing and waving, thought to be gravity dependent phenomena, occur in spaceflight plants. In the presence of an orienting light source, phenotypic trends in skewing are gravity independent, and the general patterns of directional root growth typified by a given genotype in unit gravity are recapitulated on orbit, although overall growth patterns on orbit are less uniform. Skewing appears independent of axial orientation on the ISS - suggesting that other tropisms (such as for oxygen and temperature) do not

Plant growth strategies are remodeled by spaceflight

PubMed Central

2012-01-01

Background Arabidopsis plants were grown on the International Space Station within specialized hardware that combined a plant growth habitat with a camera system that can capture images at regular intervals of growth. The Imaging hardware delivers telemetric data from the ISS, specifically images received in real-time from experiments on orbit, providing science without sample return. Comparable Ground Controls were grown in a sister unit that is maintained in the Orbital Environment Simulator at Kennedy Space Center. One of many types of biological data that can be analyzed in this fashion is root morphology. Arabidopsis seeds were geminated on orbit on nutrient gel Petri plates in a configuration that encouraged growth along the surface of the gel. Photos were taken every six hours for the 15 days of the experiment. Results In the absence of gravity, but the presence of directional light, spaceflight roots remained strongly negatively phototropic and grew in the opposite direction of the shoot growth; however, cultivars WS and Col-0 displayed two distinct, marked differences in their growth patterns. First, cultivar WS skewed strongly to the right on orbit, while cultivar Col-0 grew with little deviation away from the light source. Second, the Spaceflight environment also impacted the rate of growth in Arabidopsis. The size of the Flight plants (as measured by primary root and hypocotyl length) was uniformly smaller than comparably aged Ground Control plants in both cultivars. Conclusions Skewing and waving, thought to be gravity dependent phenomena, occur in spaceflight plants. In the presence of an orienting light source, phenotypic trends in skewing are gravity independent, and the general patterns of directional root growth typified by a given genotype in unit gravity are recapitulated on orbit, although overall growth patterns on orbit are less uniform. Skewing appears independent of axial orientation on the ISS – suggesting that other tropisms (such as

A Molecular Genetic Basis Explaining Altered Bacterial Behavior in Space

PubMed Central

Prasad, Nripesh; Levy, Shawn E.; Stodieck, Louis; Jones, Angela; Shrestha, Shristi; Klaus, David

2016-01-01

Bacteria behave differently in space, as indicated by reports of reduced lag phase, higher final cell counts, enhanced biofilm formation, increased virulence, and reduced susceptibility to antibiotics. These phenomena are theorized, at least in part, to result from reduced mass transport in the local extracellular environment, where movement of molecules consumed and excreted by the cell is limited to diffusion in the absence of gravity-dependent convection. However, to date neither empirical nor computational approaches have been able to provide sufficient evidence to confirm this explanation. Molecular genetic analysis findings, conducted as part of a recent spaceflight investigation, support the proposed model. This investigation indicated an overexpression of genes associated with starvation, the search for alternative energy sources, increased metabolism, enhanced acetate production, and other systematic responses to acidity—all of which can be associated with reduced extracellular mass transport. PMID:27806055

Redox Signaling and Its Impact on Skeletal and Vascular Responses to Spaceflight

NASA Technical Reports Server (NTRS)

Tahimic, Candice; Globus, Ruth K.

2018-01-01

Spaceflight entails exposure to numerous environmental challenges with the potential to contribute to both musculoskeletal and vascular dysfunction. The purpose of this review is to describe current understanding of microgravity and radiation impacts on the mammalian skeleton and associated vasculature at the level of the whole organism. Recent experiments from spaceflight and groundbased models have provided fresh insights into how these environmental stresses influence mechanisms that are related to redox signaling, oxidative stress, and tissue dysfunction. Emerging mechanistic knowledge on cellular defenses to radiation and other environmental stressors, including microgravity, are useful for both screening and developing interventions against spaceflight-induced deficits in bone and vascular function.

Redox Signaling and Its Impact on Skeletal and Vascular Responses to Spaceflight.

PubMed

Tahimic, Candice G T; Globus, Ruth K

2017-10-16

Spaceflight entails exposure to numerous environmental challenges with the potential to contribute to both musculoskeletal and vascular dysfunction. The purpose of this review is to describe current understanding of microgravity and radiation impacts on the mammalian skeleton and associated vasculature at the level of the whole organism. Recent experiments from spaceflight and ground-based models have provided fresh insights into how these environmental stresses influence mechanisms that are related to redox signaling, oxidative stress, and tissue dysfunction. Emerging mechanistic knowledge on cellular defenses to radiation and other environmental stressors, including microgravity, are useful for both screening and developing interventions against spaceflight-induced deficits in bone and vascular function.

Is skeletal muscle ready for long-term spaceflight and return to gravity?

NASA Technical Reports Server (NTRS)

Riley, D. A.

1999-01-01

It is now clear that prevention of muscle debilitation during spaceflight will require a broader approach than simple exercise aimed at strengthening of the muscle fibers. The levels of several hormones and receptors are altered by unloading and must be returned to homeostasis. Pharmacotherapy and gene transfer strategies to raise the relative level of structural proteins may minimize the problems faced by astronauts in readapting to Earth-gravity. Up to now, we have only minimally exploited microgravity for advancing our understanding of muscle biology. A research laboratory in the space station with a centrifuge facility (gravity control) is essential for conducting basic research in this field. Microgravity has proven an excellent tool for noninvasively perturbing the synthesis of muscle proteins in the search for molecular signals and gene regulatory factors influencing differentiation, growth, maintenance and atrophy of muscle. Understanding the relation between blood flow and interstitial edema and between workload and subsequent structural failure are but two important problems that require serious attention. The roles of hormones and growth factors in regulating gene expression and their microgravity-induced altered production are other urgent issues to pursue. These types of studies will yield information that advances basic knowledge of muscle biology and offers insights into countermeasure design. This knowledge is likely to assist rehabilitation of diseased or injured muscles in humans on Earth, especially individuals in the more vulnerable aging population and persons participating in strenuous sports. Will the skeletal muscle system be prepared for the increased exposure to microgravity and the return to gravity loading without injury when space station is operational? The answer depends in large part on continued access to space and funding of ground-based models and flight experiments. The previous two decades of spaceflight research have described

Evidence Report: Risk of Bone Fracture due to Spaceflight-Induced Changes to Bone

NASA Technical Reports Server (NTRS)

Sibonga, Jean D.; Evans, Harlan J.; Smith, Scott A.; Spector, Elisabeth R.; Yardley, Greg; Myer, Jerry

2017-01-01

Given that spaceflight may induce adverse changes in bone ultimate strength with respect to mechanical loads during and post-mission, there is a possibility a fracture may occur for activities otherwise unlikely to induce fracture prior to initiating spaceflight.

High-grain feeding alters caecal bacterial microbiota composition and fermentation and results in caecal mucosal injury in goats.

PubMed

Liu, Junhua; Xu, Tingting; Zhu, Weiyun; Mao, Shengyong

2014-08-14

The effect of high-grain (HG) feeding on caecal bacterial microbiota composition and fermentation and mucosa health is largely unknown. In the present study, ten male goats were randomly assigned to either a group fed a hay diet (0 % grain; n 5) or a group fed a HG diet (65 % grain; n 5) to characterise the changes in the composition of the bacterial community and mucosal morphology in the caecum. After 7 weeks of feeding, the HG diet decreased the caecal pH (P< 0·001) and increased (P< 0·001 to P< 0·004) the caecal digesta concentrations of total volatile fatty acids and lipopolysaccharide (LPS). Pyrosequencing of the 16S ribosomal RNA gene revealed that HG feeding increased (P= 0·001 to P= 0·009) the abundance of predominant genera Turicibacter and Clostridium in the caecal lumen and in the caecal mucosa and decreased (P< 0·001 to P< 0·009) the proportion of Bacteroides in the lumen and Mucispirillum in the mucosa compared with the hay diet. Furthermore, the HG diet-fed goats exhibited intense epithelial damage and up-regulation (P< 0·001 to P< 0·025) of the relative mRNA expression of IL-1β, IL-6, IL-12 and interferon-γ (IFN-γ) in the caecal mucosa. The correlation analysis revealed that alterations in caecal pH, LPS concentration and mucosa-associated microbiota abundance during HG feeding might partly contribute to local inflammation. Collectively, these results provide insight into the adaptive response of caecal bacterial populations to HG feeding in goats and reveal that the fermentable substrates that flow into the caecum may cause dramatic alterations in microbial compositions and play a significant role in caecal dysfunction.

NASA Astronaut Urinary Conditions Associated with Spaceflight

NASA Technical Reports Server (NTRS)

Law, Jennifer; Cole, Richard; Young, Millennia H.; Mason, Sara

2016-01-01

INTRODUCTION: Spaceflight is associated with many factors which may promote kidney stone formation, urinary retention, and/or Urinary Tract Infection (UTI). According to ISS mission predictions supplied by NASA's Integrated Medical Model, kidney stone is the second and sepsis (urosepsis as primary driver) the third most likely reason for emergent medical evacuation from the International Space Station (ISS). METHODS: Inflight and postflight medical records of NASA astronauts were reviewed for urinary retention, UTI and kidney stones during Mercury, Gemini, Apollo, Mir, Shuttle, and ISS expeditions 1-38. RESULTS: NASA astronauts have had 7 cases of kidney stones in the 12 months after flight. Three of these cases occurred within 90 to 180 days after landing and one of the seven cases occurred in the first 90 days after flight. There have been a total of 16 cases (0.018 events per person-flights) of urinary retention during flight. The event rates per mission are nearly identical between Shuttle and ISS flights (0.019 vs 0.021 events per person-flights). In 12 of the 16 cases, astronauts had taken at least one space motion sickness medication. Upon further analysis, it was determined that the odds of developing urinary retention in spaceflight is 3 times higher among astronauts who took promethazine. The female to male odds ratio for inflight urinary retention is 11:14. An astronaut with urinary retention is 25 times more likely to have a UTI with a 17% infection rate per mission. There have been 9 reported UTIs during spaceflight. DISCUSSION: It is unclear if spaceflight carries an increased post-flight risk of kidney stones. Regarding urinary retention, the female to male odds ratio is higher during flight compared to the general population where older males comprise almost all cases due to prostatic hypertrophy. This female prevalence in spaceflight is even more concerning given the fact that there have been many more males in space than females. Terrestrial

Non-invasive vibrational SFG spectroscopy reveals that bacterial adhesion can alter the conformation of grafted "brush" chains on SAM.

PubMed

Bulard, Emilie; Guo, Ziang; Zheng, Wanquan; Dubost, Henri; Fontaine-Aupart, Marie-Pierre; Bellon-Fontaine, Marie-Noëlle; Herry, Jean-Marie; Briandet, Romain; Bourguignon, Bernard

2011-04-19

Understanding bacterial adhesion on a surface is a crucial step to design new materials with improved properties or to control biofilm formation and eradication. Sum Frequency Generation (SFG) vibrational spectroscopy has been employed to study in situ the conformational response of a self-assembled monolayer (SAM) of octadecanethiol (ODT) on a gold film to the adhesion of hydrophilic and hydrophobic ovococcoid model bacteria. The present work highlights vibrational SFG spectroscopy as a powerful and unique non-invasive biophysical technique to probe and control bacteria interaction with ordered surfaces. Indeed, the SFG vibrational spectral changes reveal different ODT SAM conformations in air and upon exposure to aqueous solution or bacterial adhesion. Furthermore, this effect depends on the bacterial cell surface properties. The SFG spectral modeling demonstrates that hydrophobic bacteria flatten the ODT SAM alkyl chain terminal part, whereas the hydrophilic ones raise this ODT SAM terminal part. Microorganism-induced alteration of grafted chains can thus affect the desired interfacial functionality, a result that should be considered for the design of new reactive materials. © 2011 American Chemical Society

Spaceflight mechanics, 1993; AAS/AIAA Spaceflight Mechanics Meeting, 3rd, Pasadena, CA, Feb. 22-24, 1993, Parts 1 & 2

NASA Technical Reports Server (NTRS)

Melton, Robert G. (Editor); Wood, Lincoln J. (Editor); Thompson, Roger C. (Editor); Kerridge, Stuart J. (Editor)

1993-01-01

Papers from the third annual Spaceflight Mechanics Meeting are presented. The topics covered include the following: attitude dynamics and control; large flexible structures; intercept and rendezvous; rendezvous and orbit transfer; and trajectory optimization.

Muscle sarcomere lesions and thrombosis after spaceflight and suspension unloading

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riley, D.A.; Ellis, S.; Giometti, C.S.

1992-08-01

Extended exposure of humans to spaceflight produces a progressive loss of skeletal muscle strength. This process must be understood to design effective countermeasures. The present investigation examined hindlimb muscles from flight rats killed as close to landing as possible. Spaceflight and tail suspension-hindlimb unloading (unloaded) produced significant decreases in fiber cross-sectional areas of the adductor longus (AL), a slow-twitch antigravity muscle. However, the mean wet weight of the flight AL muscles was near normal, whereas that of the suspension unloaded AL muscles was significantly reduced. Interstitial edema within the flight AL, but not in the unloaded AL, appeared to accountmore » for this apparent disagreement.In both conditions, the slow-twitch oxidative fibers atrophied more than the fast-twitch oxidative-glycolytic fibers. Microcirculation was also compromised by spaceflight, such that there was increased formation of thrombi in the postcapillary venules and capillaries.« less

House Hearing NASA Human Spaceflight Plan

NASA Image and Video Library

2010-05-25

NASA Administrator Charles Bolden testifies during a hearing before the House Science and Technology Committee, Tuesday, May 26, 2010, at the Rayburn House office building on Capitol Hill in Washington. The hearing was to review proposed human spaceflight plan by NASA. Photo Credit: (NASA/Paul E. Alers)

Carotid and Femoral Arterial Wall Distensibility During Long-Duration Spaceflight.

PubMed

Arbeille, Philippe; Provost, Romain; Zuj, Kathryn

2017-10-01

This study aimed to assess changes in common carotid (CA) and superficial femoral (FA) arterial stiffness during long-duration spaceflight. Ultrasound imaging was used to investigate the CA and FA of 10 astronauts preflight (PRE), on flight day 15 (FD15), after 4-5 mo (FD4-5m), and 4 d after return to Earth (R+4). Arterial wall properties were assessed through the calculation of strain, stiffness (β), pressure-strain elastic modulus (Ep), and distensibility (DI). Stiffness indices were assessed for potential correlations to measurements of intima-media thickness (IMT). Significant effects of spaceflight were found for all CA stiffness indices, indicating an increase in arterial stiffness. CA strain was reduced by 34 ± 31% on FD15 and 50 ± 16% on FD4-5m and remained reduced by 42 ± 14% on R+4 with respect to PRE values. On FD4-5m, with respect to PRE values, DI was reduced by 46 ± 25% and β and Ep were increased by 124 ± 95% and 118 ± 92%, respectively. FA arterial stiffness indices appeared to show similar changes; however, a main effect of spaceflight was only found for strain. Correlation analysis showed weak but significant relationships between measurements of CA IMT and arterial stiffness indices, but no relationships were found for FA measurements. The observed change in CA and FA stiffness indices suggest that spaceflight results in an increase in arterial stiffness. That these changes were not strongly related to measurements of IMT suggests the possibility of different mechanisms contributing to the observed results.Arbeille P, Provost R, Zuj K. Carotid and femoral arterial wall distensibility during long-duration spaceflight. Aerosp Med Hum Perform. 2017; 88(10):924-930.

Falls and Fall-Prevention in Older Persons: Geriatrics Meets Spaceflight!

PubMed

Goswami, Nandu

2017-01-01

This paper provides a general overview of key physiological consequences of microgravity experienced during spaceflight and of important parallels and connections to the physiology of aging. Microgravity during spaceflight influences cardiovascular function, cerebral autoregulation, musculoskeletal, and sensorimotor system performance. A great deal of research has been carried out to understand these influences and to provide countermeasures to reduce the observed negative consequences of microgravity on physiological function. Such research can inform and be informed by research related to physiological changes and the deterioration of physiological function due to aging. For example, head-down bedrest is used as a model to study effects of spaceflight deconditioning due to reduced gravity. As hospitalized older persons spend up to 80% of their time in bed, the deconditioning effects of bedrest confinement on physiological functions and parallels with spaceflight deconditioning can be exploited to understand and combat both variations of deconditioning. Deconditioning due to bed confinement in older persons can contribute to a downward spiral of increasing frailty, orthostatic intolerance, falls, and fall-related injury. As astronauts in space spend substantial amounts of time carrying out exercise training to counteract the microgravity-induced deconditioning and to counteract orthostatic intolerance on return to Earth, it is logical to suggest some of these interventions for bed-confined older persons. Synthesizing knowledge regarding deconditioning due to reduced gravitational stress in space and deconditioning during bed confinement allows for a more comprehensive approach that can incorporate aspects such as (mal-) nutrition, muscle strength and function, cardiovascular (de-) conditioning, and cardio-postural interactions. The impact of such integration can provide new insights and lead to methods of value for both space medicine and geriatrics (Geriatrics

Physical Training for Long-Duration Spaceflight.

PubMed

Loehr, James A; Guilliams, Mark E; Petersen, Nora; Hirsch, Natalie; Kawashima, Shino; Ohshima, Hiroshi

2015-12-01

Physical training has been conducted on the International Space Station (ISS) for the past 10 yr as a countermeasure to physiological deconditioning during spaceflight. Each member space agency has developed its own approach to creating and implementing physical training protocols for their astronauts. We have divided physical training into three distinct phases (preflight, in-flight, and postflight) and provided a description of each phase with its constraints and limitations. We also discuss how each member agency (NASA, ESA, CSA, and JAXA) prescribed physical training for their crewmembers during the first 10 yr of ISS operations. It is important to understand the operational environment, the agency responsible for the physical training program, and the constraints and limitations associated with spaceflight to accurately design and implement exercise training or interpret the exercise data collected on ISS. As exploration missions move forward, resolving agency differences in physical training programs will become important to maximizing the effectiveness of exercise as a countermeasure and minimizing any mission impacts.

Fish Inner Ear Otolith Growth Under Real Microgravity (Spaceflight) and Clinorotation

NASA Astrophysics Data System (ADS)

Anken, Ralf; Brungs, Sonja; Grimm, Dennis; Knie, Miriam; Hilbig, Reinhard

2016-06-01

Using late larval stages of cichlid fish ( Oreochromis mossambicus) we have shown earlier that the biomineralization of otoliths is adjusted towards gravity by means of a neurally guided feedback loop. Centrifuge experiments, e.g., revealed that increased gravity slows down otolith growth. Microgravity thus should yield an opposite effect, i.e., larger than normal otoliths. Consequently, late larval cichlids (stage 14, vestibular system operational) were subjected to real microgravity during the 12 days FOTON-M3 spaceflight mission (OMEGAHAB-hardware). Controls were kept at 1 g on ground within an identical hardware. Animals of another batch were subsequently clinorotated within a submersed fast-rotating clinostat with one axis of rotation (2d-clinostat), a device regarded to simulate microgravity. Temperature and light conditions were provided in analogy to the spaceflight experiment. Controls were maintained at 1 g within the same aquarium. After all experiments, animals had reached late stage 21 (fish can swim freely). Maintenance under real microgravity during spaceflight resulted in significantly larger than normal otoliths (both lapilli and sagittae, involved in sensing gravity and the hearing process, respectively). This result is fully in line with an earlier spaceflight study in the course of which otoliths from late-staged swordtails Xiphophorus helleri were analyzed. Clinorotation resulted in larger than 1 g sagittae. However, no effect on lapilli was obtained. Possibly, an effect was present but too light to be measurable. Overall, spaceflight obviously induces an adaptation of otolith growth, whereas clinorotation does not fully mimic conditions of microgravity regarding late larval cichlids.

Radiation and mechanical unloading effects on mouse vertebral bone: Ground-based models of the spaceflight environment

NASA Astrophysics Data System (ADS)

Alwood, Joshua Stewart

bone in male mice. Mechanical unloading, by contrast, is shown to cause bone loss in the vertebrae via cancellous and cortical thinning that resulted in decreased whole-bone mechanical properties. The effects of mechanical unloading were altogether reversible in the vertebra after re-ambulation, though some residual alteration of trabecular morphology persisted. The combination of unloading and radiation exposure appeared to worsen the reductions of strength. Under either environmental condition, cancellous bone loss occurred near the vertebral endplates and at the centrum midplane. Finite element analysis suggested that tissue-level stresses increase in the centrum after either unloading or irradiation in agreement with the cellular-solid model of dense, plate-like trabeculae. Force-sharing between cancellous and cortical bone decreased after radiation, with stress concentrating on the cortex. In conclusion, acute exposure to spaceflight-relevant ionizing radiation altered trabecular microarchitecture and stress distribution, without a loss of whole-bone strength at the endpoints investigated, while unloading presented the greater immediate detriment to whole-bone mechanical properties. From a skeletal-health perspective, strategies to mitigate and counteract astronaut exposure to acute doses of radiation and mechanical unloading should be developed in preparation for long-term human spaceflight.

Dysrhythmias in Laypersons During Centrifuge-Simulated Suborbital Spaceflight.

PubMed

Suresh, Rahul; Blue, Rebecca S; Mathers, Charles H; Castleberry, Tarah L; Vanderploeg, James M

2017-11-01

There are limited data on cardiac dysrhythmias in laypersons during hypergravity exposure. We report layperson electrocardiograph (ECG) findings and tolerance of dysrhythmias during centrifuge-simulated suborbital spaceflight. Volunteers participated in varied-length centrifuge training programs of 2-7 centrifuge runs over 0.5-2 d, culminating in two simulated suborbital spaceflights of combined +Gz and +Gx (peak +4.0 Gz, +6.0 Gx, duration 5 s). Monitors recorded pre- and post-run mean arterial blood pressure (MAP), 6-s average heart rate (HR) collected at prespecified points during exposures, documented dysrhythmias observed on continuous 3-lead ECG, self-reported symptoms, and objective signs of intolerance on real-time video monitoring. Participating in the study were 148 subjects (43 women). Documented dysrhythmias included sinus pause (N = 5), couplet premature ventricular contractions (N = 4), bigeminy (N = 3), accelerated idioventricular rhythm (N = 1), and relative bradycardia (RB, defined as a transient HR drop of >20 bpm; N = 63). None were associated with subjective symptoms or objective signs of acceleration intolerance. Episodes of RB occurred only during +Gx exposures. Subjects had a higher post-run vs. pre-run MAP after all exposures, but demonstrated no difference in pre- and post-run HR. RB was more common in men, younger individuals, and subjects experiencing more centrifuge runs. Dysrhythmias in laypersons undergoing simulated suborbital spaceflight were well tolerated, though RB was frequently noted during short-duration +Gx exposure. No subjects demonstrated associated symptoms or objective hemodynamic sequelae from these events. Even so, heightened caution remains warranted when monitoring dysrhythmias in laypersons with significant cardiopulmonary disease or taking medications that modulate cardiac conduction.Suresh R, Blue RS, Mathers CH, Castleberry TL, Vanderploeg JM. Dysrhythmias in laypersons during centrifuge-stimulated suborbital

Global Survey on Future Trends in Human Spaceflight: the Implications for Space Tourism

NASA Astrophysics Data System (ADS)

Gurtuna, O.; Garneau, S.

2002-01-01

With the much-publicized first ever space tourist flight, of Dennis Tito, and the announcement of the second space tourist flight to take place in April 2002, it is clear that an alternative motivation for human spaceflight has emerged. Human spaceflight is no longer only about meeting the priorities of national governments and space agencies, but is also about the tangible possibility of ordinary people seeing the Earth from a previously exclusive vantage point. It is imperative that major space players look beyond the existing human spaceflight rationale to identify some of the major driving forces behind space tourism, including the evolving market potential and developments in enabling technologies. In order to determine the influence of these forces on the future of commercial human spaceflight, the responses of a Futuraspace survey on future trends in human spaceflight are analyzed and presented. The motivation of this study is to identify sought-after space destinations, explore the expected trends in enabling technologies, and understand the future role of emerging space players. The survey will reflect the opinions of respondents from around the world including North America, Europe (including Russia) and Asia. The profiles of targeted respondents from space industry, government and academia are high-level executives/managers, senior researchers, as well as former and current astronauts. The survey instrument is a questionnaire which is validated by a pilot study. The sampling method is non-probabilistic, targeting as many space experts as possible who fit our intended respondent profile. Descriptive and comparative statistical analysis methods are implemented to investigate both global and regional perceptions of future commercial trends in human spaceflight. This study is not intended to be a formal market study of the potential viability of the space tourism market. Instead, the focus is on the future trends of human spaceflight, by drawing on the

Bacterial pathogen manipulation of host membrane trafficking.

PubMed

Asrat, Seblewongel; de Jesús, Dennise A; Hempstead, Andrew D; Ramabhadran, Vinay; Isberg, Ralph R

2014-01-01

Pathogens use a vast number of strategies to alter host membrane dynamics. Targeting the host membrane machinery is important for the survival and pathogenesis of several extracellular, vacuolar, and cytosolic bacteria. Membrane manipulation promotes bacterial replication while suppressing host responses, allowing the bacterium to thrive in a hostile environment. This review provides a comprehensive summary of various strategies used by both extracellular and intracellular bacteria to hijack host membrane trafficking machinery. We start with mechanisms used by bacteria to alter the plasma membrane, delve into the hijacking of various vesicle trafficking pathways, and conclude by summarizing bacterial adaptation to host immune responses. Understanding bacterial manipulation of host membrane trafficking provides insights into bacterial pathogenesis and uncovers the molecular mechanisms behind various processes within a eukaryotic cell.

Fibroblast Growth Factor 23 in Long-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Bokhari, R.; Zwart, S. R.; Fields, E.; Heer, M.; Sibonga, J.; Smith, S. M.

2015-01-01

Many nutritional factors influence bone, from the basics of calcium and vitamin D, to factors which influence bone through acid/base balance, including protein, sodium, and more. Fibroblast growth factor 23 (FGF23) is a recently identified factor, secreted from osteocytes, which is involved in classic (albeit complex) feedback loops controlling phosphorus homeostasis through both vitamin D and parathyroid hormone (PTH) (1, 2). As osteocytes are gravity sensing cells, it is important to determine if there are changes in FGF23 during spaceflight. In extreme cases, such as chronic kidney disease, FGF23 levels are highly elevated. FGF23 imbalances, secondary to dietary influences, may contribute to skeletal demineralization and kidney stone risk during spaceflight.

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto, with Instrumentation Technology Associates, Inc., examines closely the container containing one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-06

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto, with Instrumentation Technology Associates, Inc., examines closely the container containing one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

Spaceflight and bone turnover - Correlation with a new rat model of weightlessness

NASA Technical Reports Server (NTRS)

Morey, E. R.

1979-01-01

Earlier manned spaceflight studies have revealed that the near-weightless environment of orbital flight produce certain biological effects in humans, including abnormalities in mineral metabolism. The data collected were compatible with bone mineral loss. Cosmos 782 and 936 experiments have shown a decrease in rat bone formation rate. In this paper, a rat model of weightlessness is described, which is unique in that the animal is free to move about a 360-deg arc. The model meets the requirements for an acceptable system. Data from the model and spaceflight are presented. Many of the responses noted in suspended animals indicate that the model closely mimics results from rats and man exposed to near-weightlessness during orbital spaceflight.

Re-Adaptation to 1-G of Pregnant Rats Following Exposure to Spaceflight or Centrifugation

NASA Technical Reports Server (NTRS)

Johnson, K. E.; Ronca, A. E.; Alberts, J. R.

2003-01-01

Late-pregnant rat dams were flown on a 9-day Space Shuttle mission or exposed to 1.5, 1.75 or 2-g centrifugation and compared with 1 .O-g vivarium controls. Exposure to altered gravity began on the 11th day and recovery occurred on the 20th day of the dams' 22-day pregnancy. In the 1 st experiment, comparisons were made between Flight (FLT), Synchronous (SYN; identically-housed) and Vivarium (VIV) controls. In the 2nd experiment, comparisons were made between dams centrifuged at 2-G, 1.75-G, 1.5-G, Rotational controls (1.08-G) or Stationary controls (1 G). Within three hours of recovery from either spaceflight or centrifugation, the dams' locomotor behavior was videotaped for 2 min. FLT dams showed dramatically reduced movement relative to both SYN and VIV control conditions, with significantly greater amounts of locomotor activity observed in SYN as compared to VIV dams. Significantly greater locomotor activity was observed in SYN as compared to VIV controls. In the second experiment, no differences were observed between dams exposed either 1, 1.5, 1.75, or 2-G. In both studies, the dams showed similar patterns of hindlimb rearing. Together, these findings provide quantitative evidence for decreased locomotor activity during re-adaptation to 1-g following spaceflight, but not centrifugation.

Solar Sail Spaceflight Simulation

NASA Technical Reports Server (NTRS)

Lisano, Michael; Evans, James; Ellis, Jordan; Schimmels, John; Roberts, Timothy; Rios-Reyes, Leonel; Scheeres, Daniel; Bladt, Jeff; Lawrence, Dale; Piggott, Scott

2007-01-01

The Solar Sail Spaceflight Simulation Software (S5) toolkit provides solar-sail designers with an integrated environment for designing optimal solar-sail trajectories, and then studying the attitude dynamics/control, navigation, and trajectory control/correction of sails during realistic mission simulations. Unique features include a high-fidelity solar radiation pressure model suitable for arbitrarily-shaped solar sails, a solar-sail trajectory optimizer, capability to develop solar-sail navigation filter simulations, solar-sail attitude control models, and solar-sail high-fidelity force models.

Fractography handbook of spaceflight metals

NASA Technical Reports Server (NTRS)

Derro, Rebecca J.

1993-01-01

This handbook was produced with the intention of providing failure analysts who work with space flight metals a reference of scanning electron microscope (SEM) fractographs of fracture surfaces produced under known condition. The metals and the fracture conditions were chosen to simulate situations that are encountered in spaceflight applications. This includes tensile overload at both room temperature and liquid nitrogen temperature, and fatigue at room temperature.

Spaceflight Decompression Sickness Contingency Plan

NASA Technical Reports Server (NTRS)

Dervay, Joseph P.

2007-01-01

A viewgraph presentation on the Decompression Sickness (DCS) Contingency Plan for manned spaceflight is shown. The topics include: 1) Approach; 2) DCS Contingency Plan Overview; 3) Extravehicular Activity (EVA) Cuff Classifications; 4) On-orbit Treatment Philosophy; 5) Long Form Malfunction Procedure (MAL); 6) Medical Checklist; 7) Flight Rules; 8) Crew Training; 9) Flight Surgeon / Biomedical Engineer (BME) Training; and 10) DCS Emergency Landing Site.

Validation of a predictive model for identifying febrile young infants with altered urinalysis at low risk of invasive bacterial infection.

PubMed

Velasco, R; Gómez, B; Hernández-Bou, S; Olaciregui, I; de la Torre, M; González, A; Rivas, A; Durán, I; Rubio, A

2017-02-01

In 2015, a predictive model for invasive bacterial infection (IBI) in febrile young infants with altered urine dipstick was published. The aim of this study was to externally validate a previously published set of low risk criteria for invasive bacterial infection in febrile young infants with altered urine dipstick. Retrospective multicenter study including nine Spanish hospitals. Febrile infants ≤90 days old with altered urinalysis (presence of leukocyturia and/or nitrituria) were included. According to our predictive model, an infant is classified as low-risk for IBI when meeting all the following: appearing well at arrival to the emergency department, being >21 days old, having a procalcitonin value <0.5 ng/mL and a C-reactive protein value <20 mg/L. IBI was considered as secondary to urinary tract infection if the same pathogen was isolated in the urine culture and in the blood or cerebrospinal fluid culture. A total of 391 patients with altered urine dipstick were included. Thirty (7.7 %) of them developed an IBI, with 26 (86.7 %) of them secondary to UTI. Prevalence of IBI was 2/104 (1.9 %; CI 95% 0.5-6.7) among low-risk patients vs 28/287 (9.7 %; CI 95% 6.8-13.7) among high-risk patients (p < 0.05). Sensitivity of the model was 93.3 % (CI 95% 78.7-98.2) and negative predictive value was 98.1 % (93.3-99.4). Although our predictive model was shown to be less accurate in the validation cohort, it still showed a good discriminatory ability to detect IBI. Larger prospective external validation studies, taking into account fever duration as well as the role of ED observation, should be undertaken before its implementation into clinical practice.

Carotid and Femoral Artery Intima-Media Thickness During 6 Months of Spaceflight.

PubMed

Arbeille, Philippe; Provost, Romain; Zuj, Kathryn

2016-05-01

The objective was to determine the effects of 6 mo of microgravity exposure on conduit artery diameter and wall thickness. Diagnostic images of the common carotid artery (CC) and superficial femoral artery (FA) were obtained using echography which astronauts performed on themselves after receiving minimal training in the use of ultrasound imaging. Echographic video was recorded using a volume capture method directed by a trained sonographer on the ground through videoconferencing. Vessel properties were later assessed by processing the downlinked video. Data were collected from 10 astronauts who performed the echographic video capture at the beginning of the spaceflight (day 15) and near the end of the spaceflight (day 115 to 165). In-flight and postflight measurements were compared to preflight assessments. No significant changes with spaceflight were found for CC and FA diameter. Intima-media thickness (IMT) of the CC was found to be significantly increased (12% ± 4) in all astronauts during the spaceflight (early and late flight) and remained elevated 4 d after returning to Earth. Similarly, FA IMT was increased during the flight but returned to preflight levels 4 d postflight. The experiment demonstrated that, using the volume capture method of echography, untrained astronauts were able to capture enough echographic data to display vessel images of good quality for analysis. The increase in both CC and FA IMT during the flight suggest an adaptation to microgravity and to the confined environment of spaceflight which deserves further investigation.

Point-of-Care Ultrasound for Pulmonary Concerns in Remote Spaceflight Triage Environments.

PubMed

Johansen, Benjamin D; Blue, Rebecca S; Castleberry, Tarah L; Antonsen, Erik L; Vanderploeg, James M

2018-02-01

With the development of the commercial space industry, growing numbers of spaceflight participants will engage in activities with a risk for pulmonary injuries, including pneumothorax, ebullism, and decompression sickness, as well as other concomitant trauma. Medical triage capabilities for mishaps involving pulmonary conditions have not been systematically reviewed. Recent studies have advocated the use of point-of-care ultrasound to screen for lung injury or illness. The operational utility of portable ultrasound systems in disaster relief and other austere settings may be relevant to commercial spaceflight. A systematic review of published literature was conducted concerning the use of point-of-care pulmonary ultrasound techniques in austere environments, including suggested examination protocols for triage and diagnosis. Recent studies support the utility of pulmonary ultrasound examinations when performed by skilled operators, and comparability of the results to computed tomography and chest radiography for certain conditions, with important implications for trauma management in austere environments. Pulmonary injury and illness are among the potential health risks facing spaceflight participants. Implementation of point-of-care ultrasound protocols could aid in the rapid diagnosis, triage, and treatment of such conditions. Though operator-dependent, ultrasound, with proper training, experience, and equipment, could be a valuable tool in the hands of a first responder supporting remote spaceflight operations.Johansen BD, Blue RS, Castleberry TL, Antonsen EL, Vanderploeg JM. Point-of-care ultrasound for pulmonary concerns in remote spaceflight triage environments. Aerosp Med Hum Perform. 2018; 89(2):122-129.

Endocrine relationships during human spaceflight

NASA Technical Reports Server (NTRS)

Stein, T. P.; Schluter, M. D.; Moldawer, L. L.

1999-01-01

Human spaceflight is associated with a chronic loss of protein from muscle. The objective of this study was to determine whether changes in urinary hormone excretion could identify a hormonal role for this loss. Urine samples were collected from the crews of two Life Sciences Space Shuttle missions before and during spaceflight. Data are means +/- SE with the number of subjects in parentheses. The first value is the mean preflight measurement, and the second value is the mean inflight measurement. Adrenocorticotropic hormone (ACTH) [27.7 +/- 4.4 (9) vs. 25.1 +/- 3.4 (9) ng/day], growth hormone [724 +/- 251 (9) vs. 710 +/- 206 (9) ng/day], insulin-like growth factor I [6.81 +/- 0.62 vs. 6.04 +/- 0.51 (8) nM/day], and C-peptide [44.9 +/- 8.3 (9) vs. 50.7 +/- 10.3 (9) micrograms/day] were unchanged with spaceflight. In contrast, free 3,5,3'-triiodothyronine [791 +/- 159 (9) vs. 371 +/- 41 (9) pg/day, P < 0.05], prostaglandin E2 (PGE2) [1, 064 +/- 391 (8) vs. 465 +/- 146 (8) ng/day, P < 0.05], and its metabolite PGE-M [1,015 +/- 98 (9) vs. 678 +/- 105 (9) ng/day, P < 0. 05] were decreased inflight. The urinary excretion of most hormones returned to their preflight levels during the postflight period, with the exception of ACTH [47.5 +/- 10.3 (9) ng/day], PGE2 [1,433 +/- 327 (8) ng/day], PGF2alpha, [2,786 +/- 313 (8) ng/day], and its metabolite PGF-M [4,814 +/- 402 (9) ng/day], which were all increased compared with the preflight measurement (P < 0.05). There was a trend for urinary cortisol to be elevated inflight [55.3 +/- 5. 9 (9) vs. 72.5 +/- 11.1 micrograms/day, P = 0.27] and postflight [82.7 +/- 8.6 (8) micrograms/day, P = 0.13]. The inflight human data support ground-based in vitro work showing that prostaglandins have a major role in modulating the changes in muscle protein content in response to tension or the lack thereof.

The past, present, and future of National Aeronautics and Space Administration spaceflight diet in support of microgravity rodent experiments.

PubMed

Sun, Gwo-Shing; Tou, Janet C; Yu, Diane; Girten, Beverly E; Cohen, Jacob

2014-02-01

Rodents have been the most frequently flown animal model used to study physiological responses to the space environment. In support of future of space exploration, the National Aeronautics and Space Administration (NASA) envisions an animal research program focused on rodents. Therefore, the development of a rodent diet that is suitable for the spaceflight environment including long duration spaceflight is a high priority. Recognizing the importance of nutrition in affecting spaceflight physiological responses and ensuring reliable biomedical and biological science return, NASA developed the nutrient-upgraded rodent food bar (NuRFB) as a standard diet for rodent spaceflight. Depending on future animal habitat hardware and planned spaceflight experiments, modification of the NuRFB or development of a new diet formulation may be needed, particularly for long term spaceflights. Research in this area consists primarily of internal technical reports that are not readily accessible. Therefore, the aims of this contribution are to provide a brief history of the development of rodent spaceflight diets, to review the present diet used in rodent spaceflight studies, and to discuss some of the challenges and potential solutions for diets to be used in future long-term rodent spaceflight studies. Copyright © 2014 Elsevier Inc. All rights reserved.

Ocular Counter Rolling in Astronauts After Short- and Long-Duration Spaceflight.

PubMed

Reschke, Millard F; Wood, Scott J; Clément, Gilles

2018-05-17

Ocular counter-rolling (OCR) is a reflex generated by the activation of the gravity sensors in the inner ear that stabilizes gaze and posture during head tilt. We compared the OCR measures that were obtained in 6 astronauts before, during, and after a spaceflight lasting 4-6 days with the OCR measures obtained from 6 astronauts before and after a spaceflight lasting 4-9 months. OCR in the short-duration fliers was measured using the afterimage method during head tilt at 15°, 30°, and 45°. OCR in the long-duration fliers was measured using video-oculography during whole body tilt at 25°. A control group of 7 subjects was used to compare OCR measures during head tilt and whole body tilt. No OCR occurred during head tilt in microgravity, and the response returned to normal within 2 hours of return from short-duration spaceflight. However, the amplitude of OCR was reduced for several days after return from long-duration spaceflight. This decrease in amplitude was not accompanied by changes in the asymmetry of OCR between right and left head tilt. These results indicate that the adaptation  of otolith-driven reflexes to microgravity is a long-duration process.

Cells in Spaceflight: Past, Present and Future

NASA Technical Reports Server (NTRS)

1999-01-01

The center for advanced studies in the Space Life Sciences provides a forum for scientist to think and discuss, often for the first time, the role that gravity and aspects of spaceflight may play in fundamental cellular and physiologic processes.

Experiment K-7-35: Circadian Rhythms and Temperature Regulation During Spaceflight. Part 2; Metabolism

NASA Technical Reports Server (NTRS)

Fuller, C. A.; Dotsenko, M. A.; Korolkov, V. I.; Griffin, D. W.; Stein, T. P.

1994-01-01

Energy expenditure can be regarded as the sum of two components; the basal metabolic rate and the energy costs of activity. Weight loss is usually associated with an energy deficit. A negative energy balance exists when energy intake is less that energy utilization. The deficit is made up by tissue catabolism (principally fat, but also some protein). By analyzing food and water intake, urine and fecal output, and changes in body weight, the Skylab investigators reached the unexpected conclusion that energy expenditure during spaceflight was about 5% greater than at 1 G (Leonard, 1983; Rambaut et al., 1977). Possible explanations for the human metabolic responses are an increased workload during spaceflight (Leonard, 1983), or as Rambaut and co-workers (1977) suggested, a progressive decrease in metabolic efficiency. It is likely to be very difficult to distinguish between these two possibilities in man because the activity component may be different during spaceflight than it is the ground. The problem is to measure energy expenditure with efficient precision during spaceflight in a non-invasive manner which will not interfere with other investigations or take an time. The doubly labeled water (DLW) method meets these criteria. The DLW method is the only method available for continuously measuring energy expenditure during spaceflight given the severely restricted conditions in the spaceflight environment. Therefore, this study focuses on the development and use of this procedure on nonhuman primates during spaceflight. Energy expenditure and total body water was determined in two Rhesus monkeys by the doubly labeled water (2H2'80) method. Three determinations were made. Monkey B (#2483) was studied twice, during the flight of COSMOS 2044 and during a follow-up ground control study a month later. A second monkey was studied on the ground only (Monkey D, #782).

House Hearing NASA Human Spaceflight Plan

NASA Image and Video Library

2010-05-25

NASA Administrator Charles Bolden makes a point as he testifies during a hearing before the House Science and Technology Committee, Tuesday, May 26, 2010, at the Rayburn House office building on Capitol Hill in Washington. The hearing was to review proposed human spaceflight plan by NASA. Photo Credit: (NASA/Paul E. Alers)

House Hearing NASA Human Spaceflight Plan

NASA Image and Video Library

2010-05-25

Apollo 11 Commander Neil Armstrong makes a point as he testifies during a hearing before the House Science and Technology Committee, Tuesday, May 26, 2010, at the Rayburn House office building on Capitol Hill in Washington. The hearing was to review proposed human spaceflight plan by NASA. Photo Credit: (NASA/Paul E. Alers)

House Hearing NASA Human Spaceflight Plan

NASA Image and Video Library

2010-05-25

Retired Navy Captain and commander of Apollo 17 Eugene Cernan testifies during a hearing before the House Science and Technology Committee, Tuesday, May 26, 2010, at the Rayburn House office building on Capitol Hill in Washington. The hearing was to review proposed human spaceflight plan by NASA. Photo Credit: (NASA/Paul E. Alers)

Computers in Spaceflight: the NASA Experience

NASA Technical Reports Server (NTRS)

Tomayko, James E.

1988-01-01

This book examines the computer systems used in actual spaceflight or in close support of it. Each chapter deals with either a specific program, such as Gemini or Apollo onboard computers, or a closely related set of systems, such as launch processing or mission control. A glossary of computer terms is included.

Experiment K-7-19: Pineal Physiology After Spaceflight: Relation to Rat Gonadal Function

NASA Technical Reports Server (NTRS)

Holley, D. C.; Soliman, M. R. I.; Krasnov, I.; Asadi, H.

1994-01-01

The function of pineal exposed to microgravity and spaceflight is studied. It is found that the spaceflight resulted in a stress response as indicated by adrenal hypertrophy, that gonadal function was compromised, and that the pineal may be linked as part of the mechanisms of the response noted.

Native arbuscular mycorrhizal symbiosis alters foliar bacterial community composition.

PubMed

Poosakkannu, Anbu; Nissinen, Riitta; Kytöviita, Minna-Maarit

2017-11-01

The effects of arbuscular mycorrhizal (AM) fungi on plant-associated microbes are poorly known. We tested the hypothesis that colonization by an AM fungus affects microbial species richness and microbial community composition of host plant tissues. We grew the grass, Deschampsia flexuosa in a greenhouse with or without the native AM fungus, Claroideoglomus etunicatum. We divided clonally produced tillers into two parts: one inoculated with AM fungus spores and one without AM fungus inoculation (non-mycorrhizal, NM). We characterized bacterial (16S rRNA gene) and fungal communities (internal transcribed spacer region) in surface-sterilized leaf and root plant compartments. AM fungus inoculation did not affect microbial species richness or diversity indices in leaves or roots, but the AM fungus inoculation significantly affected bacterial community composition in leaves. A total of three OTUs in leaves belonging to the phylum Firmicutes positively responded to the presence of the AM fungus in roots. Another six OTUs belonging to the Proteobacteria (Alpha, Beta, and Gamma) and Bacteroidetes were significantly more abundant in NM plants when compared to AM fungus-inoculated plants. Further, there was a significant correlation between plant dry weight and leaf microbial community compositional shift. Also, there was a significant correlation between leaf bacterial community compositional shift and foliar nitrogen content changes due to AM fungus inoculation. The results suggest that AM fungus colonization in roots has a profound effect on plant physiology that is reflected in leaf bacterial community composition.

Bone marrow mononuclears from murine tibia after spaceflight on biosatellite

NASA Astrophysics Data System (ADS)

Andreeva, Elena; Roe, Maria; Buravkova, Ludmila; Andrianova, Irina; Goncharova, Elena; Gornostaeva, Alexandra

Elucidation of the space flight effects on the adult stem and progenitor cells is an important goal in space biology and medicine. A unique opportunity for this is provided by project "BION -M1". The purpose of this study was to evaluate the effects of a 30-day flight on biosatellite "BION - M1" and the subsequent 7-day recovery on the quantity, viability, immunophenotype of mononuclears from murine tibia bone marrow. Also the in vitro characterization of functional capacity of multipotent mesenchymal stromal cells (MSCs) was scheduled. Under the project, the S57black/6 mice were divided into groups: spaceflight/vivarium control, recovery after spaceflight/ vivarium control to recovery. Bone marrow mononuclears were isolated from the tibia and immunophenotyped using antibodies against CD45, CD34, CD90 on a flow cytometer Epics XL (Beckman Coulter). A part of the each pool was frozen for subsequent estimation of hematopoietic colony-forming units (CFU), the rest was used for the evaluation of fibroblast CFU (CFUf) number, MSC proliferative activity and osteogenic potency. The cell number in the flight group was significantly lower than in the vivarium control group. There were no differences in this parameter between flight and control groups after 7 days of recovery. The mononuclears viability was more than 95 percent in all examined groups. Flow cytometric analysis showed no differences in the bone marrow cell immunophenotype (CD45, CD34, CD90.1 (Thy1)), but the flight animals had more large-sized CD45+mononuclears, than the control groups of mice. There was no difference in the CFUf number between groups. After 7 days in vitro the MSC number in flight group was twice higher than in vivarium group, after 10 days - 4 times higher. These data may indicate a higher proliferative activity of MSCs after spaceflight. MSCs showed the same and high alkaline phosphatase activity, both in flight and in the control groups, suggesting no effect of spaceflight factors on early

GeneLab: A Systems Biology Platform for Spaceflight Omics Data

NASA Technical Reports Server (NTRS)

Reinsch, Sigrid S.; Lai, San-Huei; Chen, Rick; Thompson, Terri; Berrios, Daniel; Fogle, Homer; Marcu, Oana; Timucin, Linda; Chakravarty, Kaushik; Coughlan, Joseph

2015-01-01

NASA's mission includes expanding our understanding of biological systems to improve life on Earth and to enable long-duration human exploration of space. Resources to support large numbers of spaceflight investigations are limited. NASA's GeneLab project is maximizing the science output from these experiments by: (1) developing a unique public bioinformatics database that includes space bioscience relevant "omics" data (genomics, transcriptomics, proteomics, and metabolomics) and experimental metadata; (2) partnering with NASA-funded flight experiments through bio-sample sharing or sample augmentation to expedite omics data input to the GeneLab database; and (3) developing community-driven reference flight experiments. The first database, GeneLab Data System Version 1.0, went online in April 2015. V1.0 contains numerous flight datasets and has search and download capabilities. Version 2.0 will be released in 2016 and will link to analytic tools. In 2015 Genelab partnered with two Biological Research in Canisters experiments (BBRIC-19 and BRIC-20) which examine responses of Arabidopsis thaliana to spaceflight. GeneLab also partnered with Rodent Research-1 (RR1), the maiden flight to test the newly developed rodent habitat. GeneLab developed protocols for maxiumum yield of RNA, DNA and protein from precious RR-1 tissues harvested and preserved during the SpaceX-4 mission, as well as from tissues from mice that were frozen intact during spaceflight and later dissected. GeneLab is establishing partnerships with at least three planned flights for 2016. Organism-specific nationwide Science Definition Teams (SDTs) will define future GeneLab dedicated missions and ensure the broader scientific impact of the GeneLab missions. GeneLab ensures prompt release and open access to all high-throughput omics data from spaceflight and ground-based simulations of microgravity and radiation. Overall, GeneLab will facilitate the generation and query of parallel multi-omics data, and

Alteration of chromophoric dissolved organic matter by solar UV radiation causes rapid changes in bacterial community composition.

PubMed

Piccini, Claudia; Conde, Daniel; Pernthaler, Jakob; Sommaruga, Ruben

2009-09-01

We evaluated the effect of photochemical alterations of chromophoric dissolved organic matter (CDOM) on bacterial abundance, activity and community composition in a coastal lagoon of the Atlantic Ocean with high dissolved organic carbon concentration. On two occasions during the austral summer, bacteria-free water of the lagoon was exposed to different regions of the solar spectrum (full solar radiation, UV-A+PAR, PAR) or kept in the dark. Subsequently, dilution cultures were established with bacterioplankton from the lagoon that were incubated in the pre-exposed water for 5 h in the dark. Cell abundance, activity, and community composition of bacterioplankton were assessed before and after incubation in the different treatments. Changes in absorption, fluorescence, and DOC concentration were used as proxies for CDOM photoalteration. We found a significant CDOM photobleaching signal, DOC loss, as well as a stimulation of bacterial activity in the treatments pre-exposed to UV radiation, suggesting increased bioavailability of DOM. Bacterial community analysis by fluorescence in situ hybridization revealed that this stimulation was mainly accompanied by the specific enrichment of Alpha- and Betaproteobacteria. Thus, our results suggest that CDOM photoalteration not only stimulates bacterioplankton growth, but also induces rapid changes in bacterioplankton composition, which can be of relevance for ecosystem functioning, particularly considering present and future changes in the input of terrestrial CDOM to aquatic systems.

Alteration of chromophoric dissolved organic matter by solar UV radiation causes rapid changes in bacterial community composition†

PubMed Central

Piccini, Claudia; Conde, Daniel; Pernthaler, Jakob; Sommaruga, Ruben

2010-01-01

We evaluated the effect of photochemical alterations of chromophoric dissolved organic matter (CDOM) on bacterial abundance, activity and community composition in a coastal lagoon of the Atlantic Ocean with high dissolved organic carbon concentration. On two occasions during the austral summer, bacteria-free water of the lagoon was exposed to different regions of the solar spectrum (full solar radiation, UV-A + PAR, PAR) or kept in the dark. Subsequently, dilution cultures were established with bacterioplankton from the lagoon that were incubated in the pre-exposed water for 5 h in the dark. Cell abundance, activity, and community composition of bacterioplankton were assessed before and after incubation in the different treatments. Changes in absorption, fluorescence, and DOC concentration were used as proxies for CDOM photoalteration. We found a significant CDOM photobleaching signal, DOC loss, as well as a stimulation of bacterial activity in the treatments pre-exposed to UV radiation, suggesting increased bioavailability of DOM. Bacterial community analysis by fluorescence in situ hybridization revealed that this stimulation was mainly accompanied by the specific enrichment of Alpha- and Betaproteobacteria. Thus, our results suggest that CDOM photoalteration not only stimulates bacterioplankton growth, but also induces rapid changes in bacterioplankton composition, which can be of relevance for ecosystem functioning, particularly considering present and future changes in the input of terrestrial CDOM to aquatic systems. PMID:19707620

Centrifuge-Simulated Suborbital Spaceflight in a Subject with Cardiac Malformation.

PubMed

Blue, Rebecca S; Blacher, Eric; Castleberry, Tarah L; Vanderploeg, James M

2015-11-01

Commercial spaceflight participants (SFPs) will introduce new medical challenges to the aerospace community, with unique medical conditions never before exposed to the space environment. This is a case report regarding the response of a subject with multiple cardiac malformations, including aortic insufficiency, pulmonary atresia, pulmonary valve replacement, ventricular septal defect (post-repair), and pulmonary artery stenosis (post-dilation), to centrifuge acceleration simulating suborbital flight. A 23-yr-old man with a history of multiple congenital cardiac malformations underwent seven centrifuge runs over 2 d. Day 1 consisted of two +G(z) runs (peak = +3.5 G(z), run 2) and two +G(x) runs (peak = +6.0 G(x), run 4). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +G(x) and +G(z)). Data collected included blood pressure, electrocardiogram, pulse oximetry, neurovestibular exams, and post-run questionnaires regarding motion sickness, disorientation, greyout, and other symptoms. Despite the subject's significant medical history, he tolerated the acceleration profiles well and demonstrated no significant abnormal physiological responses. Potential risks to SFPs with aortic insufficiency, artificial heart valves, or valvular insufficiency include lower +G(z) tolerance, earlier symptom onset, and ineffective mitigation strategies such as anti-G straining maneuvers. There are no prior studies of prolonged accelerations approximating spaceflight in such individuals. This case demonstrates tolerance of acceleration profiles in an otherwise young and healthy individual with significant cardiac malformations, suggesting that such conditions may not necessarily preclude participation in commercial spaceflight.

Tolerance of centrifuge-simulated suborbital spaceflight by medical condition.

PubMed

Blue, Rebecca S; Pattarini, James M; Reyes, David P; Mulcahy, Robert A; Garbino, Alejandro; Mathers, Charles H; Vardiman, Johnené L; Castleberry, Tarah L; Vanderploeg, James M

2014-07-01

We examined responses of volunteers with known medical disease to G forces in a centrifuge to evaluate how potential commercial spaceflight participants (SFPs) might tolerate the forces of spaceflight despite significant medical history. Volunteers were recruited based upon suitability for each of five disease categories (hypertension, cardiovascular disease, diabetes, lung disease, back or neck problems) or a control group. Subjects underwent seven centrifuge runs over 2 d. Day 1 consisted of two +G(z) runs (peak = +3.5 G(z), Run 2) and two +G(x), runs (peak = +6.0 G(x), Run 4). Day 2 consisted of three runs approximating suborbital spaceflight profiles (combined +G(x) and +G(z), peak = +6.0 G(x)/+4.0 G(z)). Data collected included blood pressure, electrocardiogram, pulse oximetry, neurovestibular exams, and post-run questionnaires regarding motion sickness, disorientation, grayout, and other symptoms. A total of 335 subjects registered for participation, of which 86 (63 men, 23 women, age 20-78 yr) participated in centrifuge trials. The most common causes for disqualification were weight and severe and uncontrolled medical or psychiatric disease. Five subjects voluntarily withdrew from the second day of testing: three for anxiety reasons, one for back strain, and one for time constraints. Maximum hemodynamic values recorded included HR of 192 bpm, systolic BP of 217 mmHg, and diastolic BP of 144 mmHg. Common subjective complaints included grayout (69%), nausea (20%), and chest discomfort (6%). Despite their medical history, no subject experienced significant adverse physiological responses to centrifuge profiles. These results suggest that most individuals with well-controlled medical conditions can withstand acceleration forces of launch and re-entry profiles of current commercial spaceflight vehicles.

NASA's human system risk management approach and its applicability to commercial spaceflight.

PubMed

Law, Jennifer; Mathers, Charles H; Fondy, Susan R E; Vanderploeg, James M; Kerstman, Eric L

2013-01-01

As planning continues for commercial spaceflight, attention is turned to NASA to assess whether its human system risk management approach can be applied to mitigate the risks associated with commercial suborbital and orbital flights. NASA uses a variety of methods to assess the risks to the human system based on their likelihood and consequences. In this article, we review these methods and categorize the risks in the system as "definite," "possible," or "least" concern for commercial spaceflight. As with career astronauts, these risks will be primarily mitigated by screening and environmental control. Despite its focus on long-duration exploration missions, NASA's human system risk management approach can serve as a preliminary knowledge base to help medical planners prepare for commercial spaceflights.

Risk of Crew Adverse Health Event Due to Altered Immune Response

NASA Technical Reports Server (NTRS)

Crucian, Brian; Kunz, Hawley; Sams, Clarence F.

2015-01-01

Determining the effect of space travel on the human immune system has proven to be extremely challenging. Limited opportunities for in-flight studies, varying mission durations, technical and logistical obstacles, small subject numbers, and a broad range of potential assays have contributed to this problem. Additionally, the inherent complexity of the immune system, with its vast array of cell populations, sub-populations, diverse regulatory molecules, and broad interactions with other physiological systems, makes determining precise variables to measure very difficult. There is also the challenge of determining the clinical significance of any observed immune alterations. Will such a change lead to disease, or is it a transient subclinical observation related to short-term stress? The effect of this problem may be observed by scanning publications associated with immunity and spaceflight, which began to appear during the 1970s. Although individually they are each valid studies, the comprehensive literature to date suffers from widely varying sampling methods and assay techniques, low subject counts, and sometimes a disparate focus on narrow aspects of immunity. The most clinically relevant data are derived from in-flight human studies, which have demonstrated altered cell-mediated immunity and reactivation of latent herpes viruses. Much more data are available from post-flight testing of humans, with clear evidence of altered cytokine production patterns, altered leukocyte distribution, continued latent viral reactivation, and evidence of dramatically altered virus-specific immunity. It is unknown if post-flight assessments relate to the in-flight condition or are a response to landing stress and readaptation. In-flight culture of cells has clearly demonstrated that immune cells are gravity-sensitive and display altered functional characteristics. It is unknown if these data are related to in vivo immune cell function or are an artifact of microgravity culture

Integrating Bioregenerative Foods into the Exploration Spaceflight Food System

NASA Technical Reports Server (NTRS)

Douglas, Grace L.

2017-01-01

Food, the nutrition it provides, and the eating experiences surrounding it, are central to performance, health, and psychosocial wellbeing on long duration spaceflight missions. Exploration missions will require a spaceflight food system that is safe, nutritious, and acceptable for up to five years, possibly without cold storage. Many of the processed and packaged spaceflight foods currently used on the International Space Station will not retain acceptable quality or required levels of key nutrients under these conditions. The addition of bioregenerative produce to exploration missions may become an important countermeasure to the nutritional gaps and a resource to support psychosocial health. Bioregenerative produce will be central to establishment of Earth-independence as exploration extends deeper into space. However, bioregenerative foods introduce food safety and scarcity risks that must be eliminated prior to crew reliance on these systems. The pathway to Earth independence will require small-scale integration and validation prior to large scale bioregenerative dependence. Near term exploration missions offer the opportunity to establish small scale supplemental salad crop and fruit systems and validate infrastructure reliability, nutritional potential, and the psychosocial benefits necessary to promote further bioregenerative integration.

Midodrine as a Countermeasure for Post-spaceflight Orthostatic Hypotension

NASA Technical Reports Server (NTRS)

Platts, Steven H.; Ziegler, Michael G.; Waters, Wendy W.; Meck, Janice V.

2007-01-01

Up to 30 % of astronauts exhibit post-spaceflight orthostatic hypotension due to inadequate norepinephrine release during upright posture following short duration spaceflight. We hypothesize that the (alpha)1-adrenergic agonist midodrine will be an effective countermeasure. This study is being conducted in 2 phases. The first phase is complete and consisted testing six short duration crew members. All of these subjects participated in preflight and postflight tilt testing on a control flight as well as on the test flights, where midodrine was administered after landing, 1 hour before testing. Hemodynamic variables were compared between the 2 flights. Midodrine improved stroke volume, cardiac output, systolic pressure and heart rate, without increasing vascular resistance. None of these subjects experienced orthostatic hypotension on landing day. Phase II is similar to phase I, except that midodrine is ingested in flight (near TIG) and the tilt test is performed immediately after landing on the CTV. One crewmember has completed phase II testing. This crewmember had no evidence of orthostatic hypotension or presyncope, four additional crewmembers have volunteered for this study. To date, midodrine has been shown to be a safe and effective countermeasure to post-spaceflight orthostatic hypotension.

Role of Mitochondrial Oxidative Stress in Spaceflight-Induced Tissue Degeneration

NASA Technical Reports Server (NTRS)

Torres, Samantha M.; Schreurs, Ann-Sofie; Truong, Tiffany A.; Tahimic, Candice; Globus, Ruth

2017-01-01

Microgravity and ionizing radiation in the spaceflight environment poses multiple challenges to homeostasis and may contribute to cellular stress. Effects may include increased generation of reactive oxygen species (ROS), DNA damage and repair error, cell cycle arrest, cell senescence or death. Our central hypothesis is that prolonged exposure to the spaceflight environment leads to the excess production of ROS and oxidative damage, culminating in accelerated tissue degeneration. The main goal of this project is to determine the importance of cellular redox defense for physiological adaptations and tissue degeneration in the space environment.

Muscle sarcomere lesions and thrombosis after spaceflight and suspension unloading

NASA Technical Reports Server (NTRS)

Riley, D. A.; Ellis, S.; Giometti, C. S.; Hoh, J. F. Y.; Il'ina-Kakueva, E. I.; Oganov, V. S.; Slocum, G. R.; Bain, J. L. W.; Sedlak, F. R.

1992-01-01

Data obtained during Cosmos 2044 bisatellite mission are reviewed and found to be consistent with the results of previous rodent spaceflight experiments. Investigation was carried out of hindlimb muscles from flight rats killed as close to land as possible so that changes induced by spaceflight and early readaptation to weight bearing could be distinguished from the changes that resulted from the two-day postflight period during Cosmos 1887. Results presented pertain to muscle atrophy and fiber type changes, eccentric contraction-like lesions, microcirculatory changes and interstitial edema, and tissue damage.

Responses, applications, and analysis of microgravity effects on bacteria

NASA Astrophysics Data System (ADS)

Benoit, Michael Robert

Spaceflight causes many changes to the growth and behavior of bacteria, most likely because of microgravity. However, we do not fully understand the gravity-dependent mechanisms that alter bacterial cell physiology. Furthermore, the literature consists of many contradictory results, creating controversy over the mechanisms by which spaceflight affects bacterial cultures. The research described in this dissertation combines empirical, analytical, and numerical modeling techniques aimed at characterizing the various gravity-dependent phenomena that act on bacteria. While reviewing the literature, I identified an interesting trend in prior experimental results regarding bacterial motility. With this information, we can begin to explain some of the seemingly contradictory findings. This discovery should help to resolve several controversial theories in the field of space microbiology. Chapter 3 describes a microbial antibiotic production experiment conducted onboard the International Space Station. The results corroborated earlier findings of increased antibiotic production for samples taken during the first two weeks of spaceflight. For later samples, however, a reversal occurred, showing decreased production in the spaceflight samples. This insight highlights the benefit of conducting long duration experiments in space to fully evaluate biological responses. Chapter 4 describes a novel technique for preventing bacterial cell sedimentation to partially simulate microgravity in ground-based experiments. The results of this study showed a correlation between cell sedimentation and bacterial growth. As documented in Chapter 5, I investigated the use of digital holographic interferometry to measure extracellular fluid density changes caused by bacterial metabolism. The results showed that fluid density changes surrounding individual bacteria were too small to measure directly. Therefore, I used mathematical analyses and numerical model simulations (described in Chapter 6

Effect of long-duration spaceflight on postural control during self-generated perturbations

NASA Technical Reports Server (NTRS)

Layne, C. S.; Mulavara, A. P.; McDonald, P. V.; Pruett, C. J.; Kozlovskaya, I. B.; Bloomberg, J. J.

2001-01-01

This report is the first systematic evaluation of the effects of prolonged weightlessness on the bipedal postural control processes during self-generated perturbations produced by voluntary upper limb movements. Spaceflight impacts humans in a variety of ways, one of which is compromised postflight postural control. We examined the neuromuscular activation characteristics and center of pressure (COP) motion associated with arm movement of eight subjects who experienced long-duration spaceflight (3--6 mo) aboard the Mir space station. Surface electromyography, arm acceleration, and COP motion were collected while astronauts performed rapid unilateral shoulder flexions before and after spaceflight. Subjects generally displayed compromised postural control after flight, as evidenced by modified COP peak-to-peak anterior-posterior and mediolateral excursion, and pathlength relative to preflight values. These changes were associated with disrupted neuromuscular activation characteristics, particularly after the completion of arm acceleration (i.e., when subjects were attempting to maintain upright posture in response to self-generated perturbations). These findings suggest that, although the subjects were able to assemble coordination modes that enabled them to generate rapid arm movements, the subtle control necessary to maintain bipedal equilibrium evident in their preflight performance is compromised after long-duration spaceflight.

Effect of Long-Duration Spaceflight on Postural Control During Self-Generated Perturbations

NASA Technical Reports Server (NTRS)

Layne, Charles S.; Mulavera, Ajitkumar P.; McDonald, P. Vernon; Pruett, Casey J.; Kozlovskaya, Innessa B.; Bloomberg, Jacob J.

2001-01-01

This report is the first systematic evaluation of the effects of prolonged weightlessness on the bipedal postural control processes during self-generated perturbations produced by voluntary upper limb movements. Spaceflight impacts humans in a variety of ways, one of which is compromised postflight postural control. We examined the neuromuscular activation characteristics and center of pressure motion (COP) associated with arm movement of eight subjects who experienced long duration spaceflight (3-6 months) aboard the Mir space station. Surface electromyography (EMG), arm acceleration, and COP motion were collected while astronauts performed rapid unilateral shoulder flexions prior to and after spaceflight. Subjects displayed compromised postural control after flight as evidenced by modified peak-to-peak COP anterior-posterior and medio-lateral motion and COP pathlength relative to preflight values. These changes were associated with disrupted neuromuscular activation characteristics, particularly after the completion of arm acceleration (i.e. when subjects were attempting to maintain their upright posture). These findings suggest that although the subjects were able to assemble coordination modes that enabled them to generate rapid arm movements, the subtle control necessary to maintain bipedal equilibrium evident in their preflight performance is compromised after long duration spaceflight.

Anesthesia during and Immediately after Spaceflight

NASA Technical Reports Server (NTRS)

Seubert, Christoph N.; Price, Catherine; Janelle, Gregory M.

2006-01-01

The increasing presence of humans in space and long-duration manned missions to the Moon or Mars pose novel challenges to the delivery of medical care. Even now, cumulative person-days in space exceed 80 years and preparations for a return to the Moon are actively underway. Medical care after an emergent de-orbit or an accident during a non-nominal landing must not only address the specific disease or injuries but also the challenges posed by physiologic adaptations to microgravity. In the highly autonomous situation of a long-term space mission the situation is even more complex, because personnel, equipment, specific training, and clinical experience are by definition limited. To summarize our current knowledge specifically for anesthetic care during and immediately after spaceflight, we will review physiologic adaptations to microgravity with particular emphasis on the resulting anesthetic risks, discuss veterinary experiences with anesthesia in weightlessness or in animals adapted to microgravity, describe current research that pertains to anesthesia and spaceflight and point out unresolved questions for future investigation.

Evidence for arrested bone formation during spaceflight

NASA Technical Reports Server (NTRS)

Turner, R. T.; Bobyn, J. D.; Duvall, P.; Morey, E. R.; Baylink, D. J.; Spector, M.

1982-01-01

Addressing the question of whether the bone formed in space is unusual, the morphology of bone made at the tibial diaphysis of rats before, during, and after spaceflight is studied. Evidence of arrest lines in the bone formed in space is reported suggesting that bone formation ceases along portions of the periosteum during spaceflight. Visualized by microradiography, the arrest lines are shown to be less mineralized than the surrounding bone matrix. When viewed by scanning electron microscopy, it is seen that bone fractures more readily at the site of an arrest line. These observations are seen as suggesting that arrest lines are a zone of weakness and that their formation may result in decreased bone strength in spite of normalization of bone formation after flight. The occurrence, location, and morphology of arrest lines are seen as suggesting that they are a visible result of the phenomenon of arrested bone formation.

Falls and Fall-Prevention in Older Persons: Geriatrics Meets Spaceflight!

PubMed Central

Goswami, Nandu

2017-01-01

This paper provides a general overview of key physiological consequences of microgravity experienced during spaceflight and of important parallels and connections to the physiology of aging. Microgravity during spaceflight influences cardiovascular function, cerebral autoregulation, musculoskeletal, and sensorimotor system performance. A great deal of research has been carried out to understand these influences and to provide countermeasures to reduce the observed negative consequences of microgravity on physiological function. Such research can inform and be informed by research related to physiological changes and the deterioration of physiological function due to aging. For example, head-down bedrest is used as a model to study effects of spaceflight deconditioning due to reduced gravity. As hospitalized older persons spend up to 80% of their time in bed, the deconditioning effects of bedrest confinement on physiological functions and parallels with spaceflight deconditioning can be exploited to understand and combat both variations of deconditioning. Deconditioning due to bed confinement in older persons can contribute to a downward spiral of increasing frailty, orthostatic intolerance, falls, and fall-related injury. As astronauts in space spend substantial amounts of time carrying out exercise training to counteract the microgravity-induced deconditioning and to counteract orthostatic intolerance on return to Earth, it is logical to suggest some of these interventions for bed-confined older persons. Synthesizing knowledge regarding deconditioning due to reduced gravitational stress in space and deconditioning during bed confinement allows for a more comprehensive approach that can incorporate aspects such as (mal-) nutrition, muscle strength and function, cardiovascular (de-) conditioning, and cardio-postural interactions. The impact of such integration can provide new insights and lead to methods of value for both space medicine and geriatrics (Geriatrics

Circadian misalignment affects sleep and medication use before and during spaceflight

PubMed Central

Flynn-Evans, Erin E; Barger, Laura K; Kubey, Alan A; Sullivan, Jason P; Czeisler, Charles A

2016-01-01

Sleep deficiency and the use of sleep-promoting medication are prevalent during spaceflight. Operations frequently dictate work during the biological night and sleep during the biological day, which contribute to circadian misalignment. We investigated whether circadian misalignment was associated with adverse sleep outcomes before (preflight) and during spaceflight missions aboard the International Space Station (ISS). Actigraphy and photometry data for 21 astronauts were collected over 3,248 days of long-duration spaceflight on the ISS and 11 days prior to launch (n=231 days). Sleep logs, collected one out of every 3 weeks in flight and daily on Earth, were used to determine medication use and subjective ratings of sleep quality. Actigraphy and photometry data were processed using Circadian Performance Simulation Software to calculate the estimated endogenous circadian temperature minimum. Sleep episodes were classified as aligned or misaligned relative to the estimated endogenous circadian temperature minimum. Mixed-effects regression models accounting for repeated measures were computed by data collection interval (preflight, flight) and circadian alignment status. The estimated endogenous circadian temperature minimum occurred outside sleep episodes on 13% of sleep episodes during preflight and on 19% of sleep episodes during spaceflight. The mean sleep duration in low-Earth orbit on the ISS was 6.4±1.2 h during aligned and 5.4±1.4 h (P<0.01) during misaligned sleep episodes. During aligned sleep episodes, astronauts rated their sleep quality as significantly better than during misaligned sleep episodes (66.8±17.7 vs. 60.2±21.0, P<0.01). Sleep-promoting medication use was significantly higher during misaligned (24%) compared with aligned (11%) sleep episodes (P<0.01). Use of any medication was significantly higher on days when sleep episodes were misaligned (63%) compared with when sleep episodes were aligned (49%; P<0.01). Circadian misalignment is

Circadian misalignment affects sleep and medication use before and during spaceflight.

PubMed

Flynn-Evans, Erin E; Barger, Laura K; Kubey, Alan A; Sullivan, Jason P; Czeisler, Charles A

2016-01-01

Sleep deficiency and the use of sleep-promoting medication are prevalent during spaceflight. Operations frequently dictate work during the biological night and sleep during the biological day, which contribute to circadian misalignment. We investigated whether circadian misalignment was associated with adverse sleep outcomes before (preflight) and during spaceflight missions aboard the International Space Station (ISS). Actigraphy and photometry data for 21 astronauts were collected over 3,248 days of long-duration spaceflight on the ISS and 11 days prior to launch ( n =231 days). Sleep logs, collected one out of every 3 weeks in flight and daily on Earth, were used to determine medication use and subjective ratings of sleep quality. Actigraphy and photometry data were processed using Circadian Performance Simulation Software to calculate the estimated endogenous circadian temperature minimum. Sleep episodes were classified as aligned or misaligned relative to the estimated endogenous circadian temperature minimum. Mixed-effects regression models accounting for repeated measures were computed by data collection interval (preflight, flight) and circadian alignment status. The estimated endogenous circadian temperature minimum occurred outside sleep episodes on 13% of sleep episodes during preflight and on 19% of sleep episodes during spaceflight. The mean sleep duration in low-Earth orbit on the ISS was 6.4±1.2 h during aligned and 5.4±1.4 h ( P <0.01) during misaligned sleep episodes. During aligned sleep episodes, astronauts rated their sleep quality as significantly better than during misaligned sleep episodes (66.8±17.7 vs. 60.2±21.0, P <0.01). Sleep-promoting medication use was significantly higher during misaligned (24%) compared with aligned (11%) sleep episodes ( P <0.01). Use of any medication was significantly higher on days when sleep episodes were misaligned (63%) compared with when sleep episodes were aligned (49%; P <0.01). Circadian

Adaptations of human skeletal muscle fibers to spaceflight

NASA Technical Reports Server (NTRS)

Day, M. Kathleen; Allen, David L.; Mohajerani, Laleh; Greenisen, Michael C.; Roy, Roland R.; Edgerton, V. Reggie

1995-01-01

Human skeletal muscle fibers seem to share most of the same interrelationships among myosin ATPase activity, myosin heavy chain (MHC) phenotype, mitochondrial enzyme activities, glycolytic enzyme activities, and cross-sectional area (CSA) as found in rat, cat, and other species. One difference seems to be that fast fibers with high mitochrondrial content occur less frequently in humans than in the rat or cat. Recently, we have reported that the type of MHC expressed and the size of the muscle fibers in humans that have spent 11 days in space change significantly. Specifically, about 8% more fibers express fast MHCs and all phenotypes atrophy in the vastus lateralis (VL) post compared to preflight. In the present paper we examine the relationships among the population of myonuclei, MHC type, and CSA of single human muscle fibers before and after spaceflight. These are the first data that define the relationship among the types of MHC expressed, myonuclei number, and myonuclei domain of single fibers in human muscle. We then compare these data to similar measures in the cat. In addition, the maximal torque that can be generated by the knee extensors and their fatigability before and after spaceflight are examined. These data provide some indication of the potential physiologica consequences of the muscle adaptations that occur in humans in response to spaceflight.

Black Molecular Adsorber Coatings for Spaceflight Applications

NASA Technical Reports Server (NTRS)

Abraham, Nithin Susan; Hasegawa, Mark Makoto; Straka, Sharon A.

2014-01-01

The molecular adsorber coating is a new technology that was developed to mitigate the risk of on-orbit molecular contamination on spaceflight missions. The application of this coating would be ideal near highly sensitive, interior surfaces and instruments that are negatively impacted by outgassed molecules from materials, such as plastics, adhesives, lubricants, epoxies, and other similar compounds. This current, sprayable paint technology is comprised of inorganic white materials made from highly porous zeolite. In addition to good adhesion performance, thermal stability, and adsorptive capability, the molecular adsorber coating offers favorable thermal control characteristics. However, low reflectivity properties, which are typically offered by black thermal control coatings, are desired for some spaceflight applications. For example, black coatings are used on interior surfaces, in particular, on instrument baffles for optical stray light control. Similarly, they are also used within light paths between optical systems, such as telescopes, to absorb light. Recent efforts have been made to transform the white molecular adsorber coating into a black coating with similar adsorptive properties. This result is achieved by optimizing the current formulation with black pigments, while still maintaining its adsorption capability for outgassing control. Different binder to pigment ratios, coating thicknesses, and spray application techniques were explored to develop a black version of the molecular adsorber coating. During the development process, coating performance and adsorption characteristics were studied. The preliminary work performed on black molecular adsorber coatings thus far is very promising. Continued development and testing is necessary for its use on future contamination sensitive spaceflight missions.

Black molecular adsorber coatings for spaceflight applications

NASA Astrophysics Data System (ADS)

Abraham, Nithin S.; Hasegawa, Mark M.; Straka, Sharon A.

2014-09-01

The molecular adsorber coating is a new technology that was developed to mitigate the risk of on-orbit molecular contamination on spaceflight missions. The application of this coating would be ideal near highly sensitive, interior surfaces and instruments that are negatively impacted by outgassed molecules from materials, such as plastics, adhesives, lubricants, epoxies, and other similar compounds. This current, sprayable paint technology is comprised of inorganic white materials made from highly porous zeolite. In addition to good adhesion performance, thermal stability, and adsorptive capability, the molecular adsorber coating offers favorable thermal control characteristics. However, low reflectivity properties, which are typically offered by black thermal control coatings, are desired for some spaceflight applications. For example, black coatings are used on interior surfaces, in particular, on instrument baffles for optical stray light control. Similarly, they are also used within light paths between optical systems, such as telescopes, to absorb light. Recent efforts have been made to transform the white molecular adsorber coating into a black coating with similar adsorptive properties. This result is achieved by optimizing the current formulation with black pigments, while still maintaining its adsorption capability for outgassing control. Different binder to pigment ratios, coating thicknesses, and spray application techniques were explored to develop a black version of the molecular adsorber coating. During the development process, coating performance and adsorption characteristics were studied. The preliminary work performed on black molecular adsorber coatings thus far is very promising. Continued development and testing is necessary for its use on future contamination sensitive spaceflight missions.

EcAMSat: Effect of Space-Flight on Antibiotic Resistance of a Pathogenic Bacterium and its Genetic Basis

NASA Technical Reports Server (NTRS)

Matin, A. C.; Benoit, M.; Chin. M.; Chinn, T. N.; Cohen, A.; Friedericks, C.; Henschke, M. B.; Keyhan, M.; Lera, M. P.; Padgen, M. R.;

Workplace Social Support and Behavioral Health Prior to Long-Duration Spaceflight.

PubMed

Deming, Charlene A; Vasterling, Jennifer J

2017-06-01

Preparation and training for long-duration spaceflight bring with them psychosocial stressors potentially affecting the well-being and performance of astronauts, before and during spaceflight. Social support from within the workplace may mitigate behavioral health concerns arising during the preflight period and enhance resiliency before and during extended missions. The purpose of this review was to evaluate evidence addressing the viability of workplace social support as a pre-mission countermeasure, specifically addressing: 1) the observed relationships between workplace social support and behavioral health; 2) perceived need, acceptability, and format preference for workplace social support among high-achievers; 3) potential barriers to delivery/receipt of workplace social support; 4) workplace social support interventions; and 5) delivery timeframe and anticipated duration of workplace social support countermeasure benefits. We conducted an evidence review examining workplace social support in professional contexts sharing one or more characteristics with astronauts and spaceflight. Terms included populations of interest, social support constructs, and behavioral health outcomes. Abstracts of matches were subsequently reviewed for relevance and quality. Research findings demonstrate clear associations between workplace social support and behavioral health, especially following exposure to stress. Further, studies indicate strong need for support and acceptability of support countermeasures, despite barriers. Our review revealed two general formats for providing support (i.e., direct provision of support and training to optimize skills in provision and receipt of support) with potential differentiation of expected duration of benefits, according to format. Workplace social support countermeasures hold promise for effective application during pre-mission phases of long-duration spaceflight. Specific recommendations are provided.Deming CA, Vasterling JJ

Soil bacterial community composition altered by increased nutrient availability in Arctic tundra soils

PubMed Central

Koyama, Akihiro; Wallenstein, Matthew D.; Simpson, Rodney T.; Moore, John C.

2014-01-01

The pool of soil organic carbon (SOC) in the Arctic is disproportionally large compared to those in other biomes. This large quantity of SOC accumulated over millennia due to slow rates of decomposition relative to net primary productivity. Decomposition is constrained by low temperatures and nutrient concentrations, which limit soil microbial activity. We investigated how nutrients limit bacterial and fungal biomass and community composition in organic and mineral soils within moist acidic tussock tundra ecosystems. We sampled two experimental arrays of moist acidic tussock tundra that included fertilized and non-fertilized control plots. One array included plots that had been fertilized annually since 1989 and the other since 2006. Fertilization significantly altered overall bacterial community composition and reduced evenness, to a greater degree in organic than mineral soils, and in the 1989 compared to the 2006 site. The relative abundance of copiotrophic α-Proteobacteria and β-Proteobacteria was higher in fertilized than control soils, and oligotrophic Acidobacteria were less abundant in fertilized than control soils at the 1989 site. Fungal community composition was less sensitive to increased nutrient availability, and fungal responses to fertilization were not consistent between soil horizons and sites. We detected two ectomycorrhizal genera, Russula and Cortinarius spp., associated with shrubs. Their relative abundance was not affected by fertilization despite increased dominance of their host plants in the fertilized plots. Our results indicate that fertilization, which has been commonly used to simulate warming in Arctic tundra, has limited applicability for investigating fungal dynamics under warming. PMID:25324836

Vestibuloocular reflex of rhesus monkeys after spaceflight

NASA Technical Reports Server (NTRS)

Cohen, Bernard; Kozlovskaia, Inessa; Raphan, Theodore; Solomon, David; Helwig, Denice; Cohen, Nathaniel; Sirota, Mikhail; Iakushin, Sergei

1992-01-01

The vestibuloocular reflex (VOR) of two rhesus monkeys was recorded before and after 14 days of spaceflight. The gain (eye velocity/head velocity) of the horizontal VOR, tested 15 and 18 h after landing, was approximately equal to preflight values. The dominant time constant of the animal tested 15 h after landing was equivalent to that before flight. During nystagmus induced by off-vertical axis rotation (OVAR), the latency, rising time constant, steady-state eye velocity, and phase of modulation in eye velocity and eye position with respect to head position were similar in both monkeys before and after flight. There were changes in the amplitude of modulation of horizontal eye velocity during steady-state OVAR and in the ability to discharge stored activity rapidly by tilting during postrotatory nystagmus (tilt dumping) after flight: OVAR modulations were larger, and tilt dumping was lost in the one animal tested on the day of landing and for several days thereafter. If the gain and time constant of the horizontal VOR exchange in microgravity, they must revert to normal soon after landing. The changes that were observed suggest that adaptation to microgravity had caused alterations in way that the central nervous system processes otolith input.

Exercise as a countermeasure for physiological adaptation to prolonged spaceflight

NASA Technical Reports Server (NTRS)

Convertino, V. A.

1996-01-01

Exercise represents the primary countermeasure used during spaceflight to maintain or restore maximal aerobic capacity (VO2max), musculoskeletal structure, and orthostatic function. However, no single exercise or combination of prescriptions has proven entirely effective in restoring cardiovascular and musculoskeletal functions to preflight levels following prolonged spaceflight. As human spaceflight exposures increase in duration, assessment and development of various effective exercise-based protective procedures become paramount. This must involve improvement in specific countermeasure prescription as well as development of additional approaches that will allow space travelers greater flexibility and medical safety during long flights. Effective exercise prescription will be based on identification of basic physiological stimuli that maintain normal function in terrestrial gravity and understanding of how specific combinations of exercise characteristics e.g., duration, frequency, intensity, mode) can mimic these stimuli and affect the overall process of adaptation to microgravity. This can be accomplished only with greater emphasis of research on ground-based experiments. Future attention must be directed to improving exercise compliance while minimizing both crew time and the impact of the exercise on life-support resources.

The development of lighting countermeasures for sleep disruption and circadian misalignment during spaceflight.

PubMed

Brainard, George C; Barger, Laura K; Soler, Robert R; Hanifin, John P

2016-11-01

The review addresses the development of a new solid-state lighting system for the International Space Station (ISS) that is intended to enhance the illumination of the working and living environment of astronauts and to improve sleep, circadian entrainment, and daytime alertness. Spaceflight missions often expose astronauts and mission support ground crews to atypical sleep-wake cycles and work schedules. A recent, extensive study describes the sleep characteristics and use of sleep-promoting pharmaceuticals in astronauts before, during, and after spaceflight. The acceptability, feasibility, and efficacy of the new ISS solid-state lighting systems are currently being tested in ground-based, analog studies. Installation of this lighting system on the ISS is scheduled to begin later this year. In-flight testing of this lighting system is planned to take place during ISS spaceflight expeditions. If the new ISS lighting system is capable of improving circadian entrainment and sleep during spaceflight, it should enhance astronaut health, performance, well-being, and safety. Such an advance would open the door to future lighting applications for humans living on Earth.

Building a Shared Definitional Model of Long Duration Human Spaceflight

NASA Technical Reports Server (NTRS)

Orr, M.; Whitmire, A.; Sandoval, L.; Leveton, L.; Arias, D.

2011-01-01

In 1956, on the eve of human space travel Strughold first proposed a simple classification of the present and future stages of manned flight that identified key factors, risks and developmental stages for the evolutionary journey ahead. As we look to optimize the potential of the ISS as a gateway to new destinations, we need a current shared working definitional model of long duration human space flight to help guide our path. Initial search of formal and grey literature augmented by liaison with subject matter experts. Search strategy focused on both the use of term long duration mission and long duration spaceflight, and also broader related current and historical definitions and classification models of spaceflight. The related sea and air travel literature was also subsequently explored with a view to identifying analogous models or classification systems. There are multiple different definitions and classification systems for spaceflight including phase and type of mission, craft and payload and related risk management models. However the frequently used concepts of long duration mission and long duration spaceflight are infrequently operationally defined by authors, and no commonly referenced classical or gold standard definition or model of these terms emerged from the search. The categorization (Cat) system for sailing was found to be of potential analogous utility, with its focus on understanding the need for crew and craft autonomy at various levels of potential adversity and inability to gain outside support or return to a safe location, due to factors of time, distance and location.

Exploration of Habitability Factors Influencing Short Duration Spaceflight: Structured Postflight Interviews of Shuttle Crewmembers

NASA Technical Reports Server (NTRS)

Locke, James; Leveton, Lauren; Keeton, Kathryn; Whitmire, Alexandra

2009-01-01

Astronauts report significant difficulties with sleep during Space missions. Psychological, physiological, and habitability factors are all thought to play a role in spaceflight insomnia. Crewmembers gain experience with the spaceflight sleep environment as their missions progress, but this knowledge is not formally collected and communicated to subsequent crews. This lack of information transfer prevents crews from optimizing their capability to sleep during mission, which leads to fatigue and its potentially deleterious effects. The goal of this project is astronauts with recent spaceflight experience to gather their knowledge of and insights into sleep in Space. Structured interviews consisting of standardized closed and open-ended questionnaires are administered to astronauts who have flown on the Space Shuttle since the Columbia disaster. It is hoped that review and analysis of the pooled responses to the interview questions will lead to greater understanding of the sleep environment during short duration spaceflight, with attention placed on problem aspects and their potential solutions.

The Next Spaceflight Solar Irradiance Sensor: TSIS

NASA Astrophysics Data System (ADS)

Kopp, Greg; Pilewskie, Peter; Richard, Erik

2016-05-01

The Total and Spectral Solar Irradiance Sensor (TSIS) will continue measurements of the solar irradiance with improved accuracies and stabilities over extant spaceflight instruments. The two TSIS solar-observing instruments include the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM) for measuring total- and spectral- solar-irradiance, respectively. The former provides the net energy powering the Earth’s climate system while the latter helps attribute where that energy is absorbed by the Earth’s atmosphere and surface. Both spaceflight instruments are assembled and being prepared for integration on the International Space Station. With operations commencing in late 2017, the TSIS is intended to overlap with NASA’s ongoing SOlar Radiation and Climate Experiment (SORCE) mission, which launched in 2003 and contains the first versions of both the TIM and SIM instruments, as well as with the TSI Calibration Transfer Experiment (TCTE), which began total solar irradiance measurements in 2013. We summarize the TSIS’s instrument improvements and intended solar-irradiance measurements.

A prioritized set of physiological measurements for future spaceflight experiments

NASA Technical Reports Server (NTRS)

1978-01-01

A set of desired experimental measurements to be obtained in future spaceflights in four areas of physiological investigation are identified. The basis for identifying the measurements was the physiological systems analysis performed on Skylab data and related ground-based studies. An approach for prioritizing the measurement list is identified and discussed with the use of examples. A prioritized measurement list is presented for each of the following areas; cardiopulmonary, fluid-renal and electrolyte, hematology and immunology, and musculoskeletal. Also included is a list of interacting stresses and other factors present in spaceflight experiments whose effects may need to be quantified.

Short-duration spaceflight impairs human carotid baroreceptor-cardiac reflex responses

NASA Astrophysics Data System (ADS)

Fritsch, Janice M.; Charles, John B.; Bennett, Barbara S.; Jones, Michele M.; Eckberg, Dwain L.

1992-08-01

The effect of a spaceflight on the vagally mediated baroreceptor-cardiac reflex responses of humans were investigated by measuring the responses (provoked by neck pressure changes) in supine position and the heart rate and blood pressure in the supine and standing positions in 16 astronauts before and after 4- to 5-day long Space Shuttle missions. The results showed that exposures to spaceflight resulted in reduced baseline levels of the vagal-cardiac outflow and the vagally mediated responses to changes of the arterial baroreceptor input and that these changes contribute to postflight reductions of astronauts' ability to maintain standing arterial pressures.

Summary of the Report of the U.S. National Research Council's Committee on Human Spaceflight

NASA Astrophysics Data System (ADS)

Moloney, Michael; Graham, Sandra; Angleman, Alan

Human spaceflight is considered by many to be the ultimate human endeavor in space—a pursuit to determine just how far human beings can venture into the cosmos and to understand what it is we will find and what we can do as a species in space. The U.S. National Research Council’s Committee on Human Spaceflight was charged to examine carefully and thoroughly the rationale for and value of human spaceflight in as broad a context as possible. Whereas the financial benefit of the peaceful uses of outer space, such as using space-based assets for communication systems or weather prediction, might be clear and the scientific benefits of the robotic exploration of our cosmos might be compelling, understanding the extent to which the world needs or desires human spaceflight requires a much more nuanced and complex assessment. This paper will focus on this committee’s assessment of these questions and describe the findings and recommendations of the committee’s report—in particular, examining the long-term goals and direction of a sustainable future for human spaceflight. The report, which will be released in Spring 2014, examines the rationales and benefits of human spaceflight—in the context the needs of science, industry, international relations and partnerships, and the public good—and a sustainable pathway approach to human deep space exploration. The talk would present the committee's understanding of the rationales, pathways, and decision rules that could enable and guide future planning of human space exploration. This US-NRC study was requested by the U.S. Congress and supported by the National Aeronautics and Space Administration (NASA). Conducted over 18 months, a committee of experts, drawn from diverse areas of expertise spanning the National Academies system, the study: • Considered the goals for human spaceflight and the expected value of NASA’s human spaceflight activities in the context of national goals, • Solicited broadly-based, but

Dragon paves the way for new spaceflight era

NASA Astrophysics Data System (ADS)

Gwynne, Peter

2012-07-01

The success of the first private mission to the International Space Station (ISS) has opened up a new era in commercial spaceflight after SpaceX's Dragon capsule splashed down safely in the Pacific Ocean on 31 May.

Crewmember Performance before, during, and after Spaceflight

ERIC Educational Resources Information Center

Kelly, Thomas H.; Hienz, Robert D.; Zarcone, Troy J.; Wurster, Richard M.; Brady, Joseph V.

2005-01-01

The development of technologies for monitoring the welfare of crewmembers is a critical requirement for extended spaceflight. Behavior analytic methodologies provide a framework for studying the performance of individuals and groups, and brief computerized tests have been used successfully to examine the impairing effects of sleep, drug, and…

A Psychiatric Formulary for Long-Duration Spaceflight.

PubMed

Friedman, Eric; Bui, Brian

2017-11-01

Behavioral health is essential for the safety, well-being, and performance of crewmembers in both human spaceflight and Antarctic exploration. Over the past five decades, psychiatric issues have been documented in orbital spaceflight. In Antarctica, literature suggests up to 5% of wintering crewmembers could meet criteria for a psychiatric illness, including mood disorders, stressor-related disorders, sleep-wake disorders, and substance-related disorders. Experience from these settings indicates that psychiatric disorders on deep space missions must be anticipated. An important part of planning for the psychological health of crewmembers is the onboard provision of psychotropic drugs. These medications have been available on orbital missions. A greater variety and supply of these drugs exist at Antarctic facilities. The size and diversity of a deep space psychiatric formulary will be greater than that provided on orbital missions. Drugs to be provisioned include anxiolytics, antidepressants, mood stabilizers, antipsychotics, and hypnotics. Each drug category should include different medications, providing diverse pharmacokinetic, pharmacodynamic, and side effect profiles. The formulary itself should be rigorously controlled, given the abuse potential of some medications. In-flight treatment strategies could include psychological monitoring of well-being and early intervention for significant symptoms. Psychiatric emergencies would be treated aggressively with behavioral and pharmacological interventions to de-escalate potentially hazardous situations. On long-duration space missions, a robust psychiatric formulary could provide crewmembers autonomy and flexibility in treating a range of behavioral issues from depression to acute psychosis. This will contribute to the safety, health, and performance of crewmembers, and to mission success.Friedman E, Bui B. A psychiatric formulary for long-duration spaceflight. Aerosp Med Hum Perform. 2017; 88(11):1024-1033.

Proteomic alterations in root tips of Arabidopsis thaliana seedlings under altered gravity conditions

NASA Astrophysics Data System (ADS)

Zheng, H. Q.; Wang, H.

Gravity has a profound influence on plant growth and development Removed the influence of gravitational acceleration by spaceflight caused a wide range of cellular changes in plant Whole seedling that germinated and grown on clinostats showed the absent of gravitropism At the cellular level clinostat treatment has specific effects on plant cells such as induce alterations in cell wall composition increase production of heat-soluble proteins impact on the cellular energy metabolism facilitate a uniform distribution of plastids amyloplasts and increase number and volume of nucleoli A number of recent studies have shown that the exposure of Arabidopsis seedlings and callus cells to gravity stimulation hyper g-forces or clinostat rotation induces alterations in gene expression In our previous study the proteome of the Arabidopsis thaliana callus cells were separated by high resolution two-dimensional electrophoresis 2-DE Image analysis revealed that 80 protein spots showed quantitative and qualitative variations after exposure to clinostat rotation treatment We report here a systematic proteomic approach to investigate the altered gravity responsive proteins in root tip of Arabidopsis thaliana cv Landsberg erecta Three-day-old seedlings were exposed for 12h to a horizontal clinostat rotation H simulated weightlessness altered g-forces by centrifugation 7g hypergravity a vertical clinostat rotation V clinostat control or a stationary control grown conditions Total proteins of roots were extracted

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto, Instrumentation Technology Associates, Inc., studies one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation. The latter was sponsored by the Pembroke Pines Charter Middle School.

NASA Image and Video Library

2003-05-07

KENNEDY SPACE CENTER, FLA. - Valerie Cassanto, Instrumentation Technology Associates, Inc., studies one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation. The latter was sponsored by the Pembroke Pines Charter Middle School.

KENNEDY SPACE CENTER, FLA. - From left, Bob McLean, Southwest Texas State University, and Valerie Cassanto, Instrumentation Technology Associates, Inc., study one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-07

KENNEDY SPACE CENTER, FLA. - From left, Bob McLean, Southwest Texas State University, and Valerie Cassanto, Instrumentation Technology Associates, Inc., study one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

KENNEDY SPACE CENTER, FLA. - From left, Valerie Cassanto, Instrumentation Technology Associates, Inc., and Dr. Dennis Morrison, NASA Johnson Space Center, analyze one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-07

KENNEDY SPACE CENTER, FLA. - From left, Valerie Cassanto, Instrumentation Technology Associates, Inc., and Dr. Dennis Morrison, NASA Johnson Space Center, analyze one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

The effect of spaceflight on mouse olfactory bulb volume, neurogenesis, and cell death indicates the protective effect of novel environment.

PubMed

Latchney, Sarah E; Rivera, Phillip D; Mao, Xiao W; Ferguson, Virginia L; Bateman, Ted A; Stodieck, Louis S; Nelson, Gregory A; Eisch, Amelia J

2014-06-15

Space missions necessitate physiological and psychological adaptations to environmental factors not present on Earth, some of which present significant risks for the central nervous system (CNS) of crewmembers. One CNS region of interest is the adult olfactory bulb (OB), as OB structure and function are sensitive to environmental- and experience-induced regulation. It is currently unknown how the OB is altered by spaceflight. In this study, we evaluated OB volume and neurogenesis in mice shortly after a 13-day flight on Space Shuttle Atlantis [Space Transport System (STS)-135] relative to two groups of control mice maintained on Earth. Mice housed on Earth in animal enclosure modules that mimicked the conditions onboard STS-135 (AEM-Ground mice) had greater OB volume relative to mice maintained in standard housing on Earth (Vivarium mice), particularly in the granule (GCL) and glomerular (GL) cell layers. AEM-Ground mice also had more OB neuroblasts and fewer apoptotic cells relative to Vivarium mice. However, the AEM-induced increase in OB volume and neurogenesis was not seen in STS-135 mice (AEM-Flight mice), suggesting that spaceflight may have negated the positive effects of the AEM. In fact, when OB volume of AEM-Flight mice was considered, there was a greater density of apoptotic cells relative to AEM-Ground mice. Our findings suggest that factors present during spaceflight have opposing effects on OB size and neurogenesis, and provide insight into potential strategies to preserve OB structure and function during future space missions. Copyright © 2014 the American Physiological Society.

Things That Scientists Don't Understand About NASA Spaceflight Research

NASA Technical Reports Server (NTRS)

Platts, S. H.; Bauer, Terri; Rogers, Shanna

2017-01-01

So you want to conduct human spaceflight research aboard the International Space Station (ISS)? Once your spaceflight research aboard the ISS is proposal is funded.... the real work begins. Because resources are so limited for ISS research, it is necessary to maximize the work being done, while at the same time, minimizing the resources spent. Astronauts may be presented with over 30 human research experiments and select, on average approximately 15 in which to participate. In order to conduct this many studies, ISSMP uses the study requirements provided by the principle investigator to integrate all of this work into the astronauts' complement. The most important thing for investigators to convey to the ISSMP team is their RESEARCH REQUIREMENTS. Requirements are captured in the Experiment document. This document is the official record of how, what, where and when data will be collected. One common mistake that investigators make is not taking this document seriously, but when push comes to shove, if a research requirement is not in this document....it will not get done. The research requirements are then integrated to form a complement of research for each astronaut. What do we mean by integration? Many experiments have overlapping requirements; blood draws, behavioral surveys, heart rate measurement. Where possible, these measures are combined to reduce redundancy and save crew time. Investigators can access these data via data sharing agreements. More examples of how ISS research is integrated will be presented. There are additional limitations commonly associated with human spaceflight research that will also be discussed. Large/heavy hardware, invasive procedures, and toxic reagents are extremely difficult to implement on the ISS. There are strict limits placed on the amount of blood that can be drawn from crew members during (and immediately after) spaceflight. These limits are based on 30-day rolling accumulations. We have recently had to start restricting

Energy expenditure and balance during spaceflight on the space shuttle

NASA Technical Reports Server (NTRS)

Stein, T. P.; Leskiw, M. J.; Schluter, M. D.; Hoyt, R. W.; Lane, H. W.; Gretebeck, R. E.; LeBlanc, A. D.

1999-01-01

The objectives of this study were as follows: 1) to measure human energy expenditure (EE) during spaceflight on a shuttle mission by using the doubly labeled water (DLW) method; 2) to determine whether the astronauts were in negative energy balance during spaceflight; 3) to use the comparison of change in body fat as measured by the intake DLW EE, 18O dilution, and dual energy X-ray absorptiometry (DEXA) to validate the DLW method for spaceflight; and 4) to compare EE during spaceflight against that found with bed rest. Two experiments were conducted: a flight experiment (n = 4) on the 16-day 1996 life and microgravity sciences shuttle mission and a 6 degrees head-down tilt bed rest study with controlled dietary intake (n = 8). The bed rest study was designed to simulate the flight experiment and included exercise. Two EE determinations were done before flight (bed rest), during flight (bed rest), and after flight (recovery). Energy intake and N balance were monitored for the entire period. Results were that body weight, water, fat, and energy balance were unchanged with bed rest. For the flight experiment, decreases in weight (2.6 +/- 0.4 kg, P < 0.05) and N retention (-2. 37 +/- 0.45 g N/day, P < 0.05) were found. Dietary intake for the four astronauts was reduced in flight (3,025 +/- 180 vs. 1,943 +/- 179 kcal/day, P < 0.05). EE in flight was 3,320 +/- 155 kcal/day, resulting in a negative energy balance of 1,355 +/- 80 kcal/day (-15. 7 +/- 1.0 kcal. kg-1. day-1, P < 0.05). This corresponded to a loss of 2.1 +/- 0.4 kg body fat, which was within experimental error of the fat loss determined by 18O dilution (-1.4 +/- 0.5 kg) and DEXA (-2.4 +/- 0.4 kg). All three methods showed no change in body fat with bed rest. In conclusion, 1) the DLW method for measuring EE during spaceflight is valid, 2) the astronauts were in severe negative energy balance and oxidized body fat, and 3) in-flight energy (E) requirements can be predicted from the equation: E = 1.40 x resting

Spaceflight-relevant stem education and outreach: Social goals and priorities

NASA Astrophysics Data System (ADS)

Caldwell, Barrett S.

2015-07-01

This paper is based on a presentation and conference proceedings paper given at the 65th International Astronautical Congress. The paper addresses concerns in education and public outreach (EPO) in science, technology, engineering and mathematics (STEM). The author serves as a Director of a US statewide NASA-funded Space Grant Consortium, with responsibilities to coordinate funding for undergraduate scholarships, graduate fellowships, and program awards. Space Grant is a national NASA network of STEM EPO programs including over 1000 higher education, outreach center, science museum, local government, and corporate partners. As a Space Grant Director, the author interacts with a variety of levels of STEM literacy and sophistication among members of the public. A number of interactions highlight the need for STEM EPO leaders to speak directly to a variety of social goals and priorities. Spaceflight is largely seen as an appealing and potentially desirable STEM application. However, members of the public are often unclear and ill-informed regarding relative expense, relative benefit, and relative breadth of domains of expertise that are relevant to the spaceflight enterprise. In response (and resulting in further disconnects between STEM specialists and the public), focused STEM professionals frequently over-emphasize their own technical specialty and its priority in general because of its importance to that professional. These potential divides in the attempt to share and connect STEM related goals and priorities are discussed as an elaboration of invitations to discuss spacefaring in "futures forum" contexts. Spaceflight can be seen as addressing a combination of "actualization" and "aspirational" goals at social and societal levels. Maslow's hierarchy of needs distinguishes between "basic needs" and "actualization" as a higher-order need. Another aspect of spaceflight is aspirational-it speaks to hopes and desires for levels of flexibility and capability at the

Spaceflight effects on biomechanical and biochemical properties of rat vertebrae

NASA Technical Reports Server (NTRS)

Zernicke, R. F.; Vailas, A. C.; Grindeland, R. E.; Kaplansky, A.; Salem, G. J.; Martinez, D. A.

1990-01-01

The biomechanical and biochemical responses of lumbar vertebral bodies during a 12.5-day spaceflight (Cosmos 1887 biosatellite) were determined for rapidly growing rats (90-day-old, Czechoslovakian-Wistar). By use of age-matched vivarium controls (normal cage environment) and synchronous controls (simulated flight conditions), as well as a basal control group (killed before lift-off on the 1st day of flight), the combined influences of growth and space-flight could be examined. Centra of the sixth lumbar vertebrae (L6) were compressed to 50% strain at a fast strain rate while immersed in physiological buffer (37 degrees C). The body masses of vivarium and synchronous controls were significantly heavier than either the flight or basal controls. The flight group had an L6 vertebral body compressional stiffness that was 39% less than the vivarium controls, 47% less than the synchronous control, and 16% less than the basal controls. In addition, the average initial maximum load of the flight L6 was 22% less than vivarium controls and 18% less than the synchronous controls, whereas the linear compressional load of the flight group averaged 34% less than the vivarium and 25% less than the synchronous groups. The structural properties of the vertebrae from the 12.5-day-younger basal group closely resembled the flight vertebrae. Calcium, phosphorous, and hydroxyproline concentrations were not significantly different among the groups. Nevertheless, the lack of strength and stiffness development in spaceflight, coupled with a smaller proportion of mature hydroxypyridinoline cross-links, suggested that the 12.5 days of spaceflight slowed the maturation of trabecular bone in the vertebral bodies of rapidly growing rats.

Defining Operational Space Suit Requirements for Commercial Orbital Spaceflight

NASA Technical Reports Server (NTRS)

Alpert, Brian K.

2015-01-01

As the commercial spaceflight industry transitions from suborbital brevity to orbital outposts, spacewalking will become a major consideration for tourists, scientists, and hardware providers. The challenge exists to develop a space suit designed for the orbital commercial spaceflight industry. The unique needs and requirements of this industry will drive space suit designs and costs that are unlike any existing product. Commercial space tourists will pay for the experience of a lifetime, while scientists may not be able to rely on robotics for all operations and external hardware repairs. This study was aimed at defining space suit operational and functional needs across the spectrum of spacewalk elements, identifying technical design drivers and establishing appropriate options. Recommendations from the analysis are offered for consideration

Effect of spaceflight hardware on the skeletal properties of ground control mice

NASA Astrophysics Data System (ADS)

Bateman, Ted; Lloyd, Shane; Dunlap, Alex; Ferguson, Virginia; Simske, Steven; Stodieck, Louis; Livingston, Eric

Introduction: Spaceflight experiments using mouse or rat models require habitats that are specifically designed for the microgravity environment. During spaceflight, rodents are housed in a specially designed stainless steel meshed cage with gravity-independent food and water delivery systems and constant airflow to push floating urine and feces towards a waste filter. Differences in the housing environment alone, not even considering the spaceflight environment itself, may lead to physiological changes in the animals contained within. It is important to characterize these cage differences so that results from spaceflight experiments can be more reliably compared to studies from other laboratories. Methods: For this study, we examined the effect of NASA's Animal Enclosure Module (AEM) spaceflight hardware on the skeletal properties of 8-week-old female C57BL/6J mice. This 13-day experiment, conducted on the ground, modeled the flight experiment profile of the CBTM-01 payload on STS-108, with standard vivarium-housed mice being compared to AEM-housed mice (n = 12/group). Functional differences were compared via mechanical testing, micro-hardness indentation, microcomputed tomography, and mineral/matrix composition. Cellular changes were examined by serum chemistry, histology, quantitative histomorphometry, and RT-PCR. A Student's t-test was utilized, with the level of Type I error set at 95 Results: There was no change in elastic, maximum, or fracture force mechanical properties at the femur mid-diaphysis, however, structural stiffness was -17.5 Conclusions: Housing mice in the AEM spaceflight hardware had minimal effects on femur cortical bone properties. However, trabecular bone at the proximal tibia in AEM mice experi-enced large increases in microarchitecture and mineral composition. Increases in bone density were accompanied by reductions in bone-forming osteoblasts and bone-resorbing osteoclasts, representing a general decline in bone turnover at this site

Thermal design and turbidity sensor for autonomous bacterial growth measurements in spaceflight.

PubMed

van Benthem, Roel; Krooneman, Janneke; de Grave, Wubbo; Hammenga-Dorenbos, Hilma

2009-04-01

For application of biological air filters in manned spacecraft, research on bacterial growth is carried out under microgravity conditions. For the BIOFILTER experiment, flown in 2005 on FOTON M2, eight turbidity sensors to measure the growth rate of the bacterium Xanthobacter autotrophicus GJ10 were used. Also thermal management provisions were implemented to control the internal temperature. The design and performance of the BIOFILTER equipment as well as results of the biological ground reference experiments performed in 2006 are discussed. High-performance thermal (vacuum) insulation (lambda= 0.7 mW/mK) and phase change material were implemented, keeping the BIOFILTER internal temperature below 16 degrees C during the 4-day integration period between transport and launch. After launch, in microgravity, the growth of X. autotrophicus GJ10 was successfully triggered by a temperature increase by using an internal heater to 26 degrees C. Although the operation of the sensor electronics was not fully satisfying, the bacterial growth was measured with the sensors, revealing growth rates between 0.046 and 0.077 h(-1) in microgravity, that is, approximately 1.5-2.5 times slower than routinely measured on Earth under optimal laboratory conditions. For the ground-reference experiments the equipment box, containing the eight sensors, was placed on a random positioning machine performing random rotations at 0.5 degrees /min (settling compensation) and 90 degrees /min (microgravity simulation) while the environment was controlled, accurately repeating the BIOFILTER internal temperature profile. Despite the rotation speed differences, growth rates of 0.115 h(-1) were confirmed by both the ground reference experiments. Biological interpretation of the measurements is, however, compromised owing to poor mixing and other unknown physical and biological phenomena that need to be addressed for further space experiments using these kinds of systems.

Comparative transcriptomics indicate changes in cell wall organization and stress response in seedlings during spaceflight.

PubMed

Johnson, Christina M; Subramanian, Aswati; Pattathil, Sivakumar; Correll, Melanie J; Kiss, John Z

2017-08-21

Plants will play an important role in the future of space exploration as part of bioregenerative life support. Thus, it is important to understand the effects of microgravity and spaceflight on gene expression in plant development. We analyzed the transcriptome of Arabidopsis thaliana using the Biological Research in Canisters (BRIC) hardware during Space Shuttle mission STS-131. The bioinformatics methods used included RMA (robust multi-array average), MAS5 (Microarray Suite 5.0), and PLIER (probe logarithmic intensity error estimation). Glycome profiling was used to analyze cell wall composition in the samples. In addition, our results were compared to those of two other groups using the same hardware on the same mission (BRIC-16). In our BRIC-16 experiments, we noted expression changes in genes involved in hypoxia and heat shock responses, DNA repair, and cell wall structure between spaceflight samples compared to the ground controls. In addition, glycome profiling supported our expression analyses in that there was a difference in cell wall components between ground control and spaceflight-grown plants. Comparing our studies to those of the other BRIC-16 experiments demonstrated that, even with the same hardware and similar biological materials, differences in results in gene expression were found among these spaceflight experiments. A common theme from our BRIC-16 space experiments and those of the other two groups was the downregulation of water stress response genes in spaceflight. In addition, all three studies found differential regulation of genes associated with cell wall remodeling and stress responses between spaceflight-grown and ground control plants. © 2017 Botanical Society of America.

Cosmos 1129 - Spaceflight and bone changes

NASA Technical Reports Server (NTRS)

Wronski, T. J.; Morey-Holton, E.; Jee, W. S. S.

1980-01-01

Male Wistar rats were placed in orbit for an 18.5 day period aboard the Soviet Cosmos 1129 biological satellite. The skeletal changes which occurred during spaceflight were determined to be a reduced rate of periosteal bone formation in the tibial and humeral diaphyses, and a decreased trabecular bone volume and an increased fat content of the bone marrow in the proximal tibial metaphysis.

Human muscle sympathetic neural and haemodynamic responses to tilt following spaceflight

NASA Technical Reports Server (NTRS)

Levine, Benjamin D.; Pawelczyk, James A.; Ertl, Andrew C.; Cox, James F.; Zuckerman, Julie H.; Diedrich, Andre; Biaggioni, Italo; Ray, Chester A.; Smith, Michael L.; Iwase, Satoshi;

Spaceflight-Induced Cardiovascular Changes and Recovery During NASA's Functional Task Test

NASA Technical Reports Server (NTRS)

Arzeno, N. M.; Stenger, M. B.; Bloomberg, J. J.; Platts, S. H.

2010-01-01

Microgravity-induced physiological changes could impair a crewmember s performance upon return to a gravity environment. The Functional Task Test (FTT) is designed to correlate these physiological changes to performance in mission-critical tasks. The Recovery from Fall/Stand Test (RFST) simulates one such task, measuring the ability to recover from a prone position and the cardiovascular response to orthostasis. The purpose of this study was to evaluate spaceflight-induced cardiovascular changes during the FTT. METHODS: Five astronauts participated in the FTT before 10-15 day missions, on landing day (R+0), and one (R+1), six (R+6) and thirty (R+30) days after landing. The RFST consisted of a 2-minute prone rest followed by a 3-minute stand during which heart rate (HR, Holter) and continuous blood pressure (BP, Finometer) were measured. Spectral heart rate variability (HRV) was calculated during the RFST to approximate autonomic function. Statistical analysis was performed with two-factor repeated measures ANOVA. RESULTS: During RFST, HR was higher on R+0 than preflight (p<0.004). This increase in HR persisted on R+1 and R+6 during the stand portion of RFST (p<0.026). BP was well-regulated on all test days. Parasympathetic activity was diminished on R+0 (p=0.035). Sympathovagal balance tended to be affected by spaceflight (main effect, p=0.072), appearing to be slightly elevated during postflight RFST except on R+30. Additionally, analysis of HR during the functional tasks yielded a higher HR on R+0 than preflight during 8 of 11 tasks analyzed, where all tasks had HR return to preflight values by R+30 (p<0.05). CONCLUSION: Spaceflight causes an increase in HR, decrease in parasympathetic activity, and increase in sympathovagal balance, which we confirmed during RFST. These spaceflight-induced changes seen in the RFST, along with the increased postflight HR in most functional tasks, can be used to assess functional performance after short-duration spaceflight.

Human muscle sympathetic neural and haemodynamic responses to tilt following spaceflight

PubMed Central

Levine, Benjamin D; Pawelczyk, James A; Ertl, Andrew C; Cox, James F; Zuckerman, Julie H; Diedrich, André; Biaggioni, Italo; Ray, Chester A; Smith, Michael L; Iwase, Satoshi; Saito, Mitsuru; Sugiyama, Yoshiki; Mano, Tadaaki; Zhang, Rong; Iwasaki, Kenichi; Lane, Lynda D; Buckey, Jay C; Cooke, William H; Baisch, Friedhelm J; Robertson, David; Eckberg, Dwain L; Blomqvist, C Gunnar

2002-01-01

Orthostatic intolerance is common when astronauts return to Earth: after brief spaceflight, up to two-thirds are unable to remain standing for 10 min. Previous research suggests that susceptible individuals are unable to increase their systemic vascular resistance and plasma noradrenaline concentrations above pre-flight upright levels. In this study, we tested the hypothesis that adaptation to the microgravity of space impairs sympathetic neural responses to upright posture on Earth. We studied six astronauts ∼72 and 23 days before and on landing day after the 16 day Neurolab space shuttle mission. We measured heart rate, arterial pressure and cardiac output, and calculated stroke volume and total peripheral resistance, during supine rest and 10 min of 60 deg upright tilt. Muscle sympathetic nerve activity was recorded in five subjects, as a direct measure of sympathetic nervous system responses. As in previous studies, mean (± s.e.m.) stroke volume was lower (46 ± 5 vs. 76 ± 3 ml, P = 0.017) and heart rate was higher (93 ± 1 vs. 74 ± 4 beats min−1, P = 0.002) during tilt after spaceflight than before spaceflight. Total peripheral resistance during tilt post flight was higher in some, but not all astronauts (1674 ± 256 vs. 1372 ± 62 dynes s cm−5, P = 0.32). No crew member exhibited orthostatic hypotension or presyncopal symptoms during the 10 min of postflight tilting. Muscle sympathetic nerve activity was higher post flight in all subjects, in supine (27 ± 4 vs. 17 ± 2 bursts min−1, P = 0.04) and tilted (46 ± 4 vs. 38 ± 3 bursts min−1, P = 0.01) positions. A strong (r2 = 0.91–1.00) linear correlation between left ventricular stroke volume and muscle sympathetic nerve activity suggested that sympathetic responses were appropriate for the haemodynamic challenge of upright tilt and were unaffected by spaceflight. We conclude that after 16 days of spaceflight, muscle sympathetic nerve responses to upright tilt are normal. PMID:11773340

Spaceflight exposure effects on transcription, activity, and localization of alcohol dehydrogenase in the roots of Arabidopsis thaliana.

PubMed Central

Porterfield, D M; Matthews, S W; Daugherty, C J; Musgrave, M E

1997-01-01

Although considerable research and speculation have been directed toward understanding a plant's perception of gravity and the resulting gravitropic responses, little is known about the role of gravity-dependent physical processes in normal physiological function. These studies were conducted to determine whether the roots of plants exposed to spaceflight conditions may be experiencing hypoxia. Arabidopsis thaliana (L.) Heynh. plants were grown in agar medium during 6 or 11 d of spaceflight exposure on shuttle missions STS-54 (CHROMEX-03) and STS-68 (CHROMEX-05), respectively. The analysis included measurement of agar redox potential and root alcohol dehydrogenase (ADH) activity, localization, and expression. ADH activity increased by 89% as a result of spaceflight exposure for both CHROMEX-03 and -05 experiments, and ADH RNase protection assays revealed a 136% increase in ADH mRNA. The increase in ADH activity associated with the spaceflight roots was realized by a 28% decrease in oxygen availability in a ground-based study; however, no reduction in redox potential was observed in measurements of the spaceflight bulk agar. Spaceflight exposure appears to effect a hypoxic response in the roots of agar-grown plants that may be caused by changes in gravity-mediated fluid and/or gas behavior. PMID:9085569

Spaceflight exposure effects on transcription, activity, and localization of alcohol dehydrogenase in the roots of Arabidopsis thaliana

NASA Technical Reports Server (NTRS)

Porterfield, D. M.; Matthews, S. W.; Daugherty, C. J.; Musgrave, M. E.

1997-01-01

Although considerable research and speculation have been directed toward understanding a plant's perception of gravity and the resulting gravitropic responses, little is known about the role of gravity-dependent physical processes in normal physiological function. These studies were conducted to determine whether the roots of plants exposed to spaceflight conditions may be experiencing hypoxia. Arabidopsis thaliana (L.) Heynh. plants were grown in agar medium during 6 or 11 d of spaceflight exposure on shuttle missions STS-54 (CHROMEX-03) and STS-68 (CHROMEX-05), respectively. The analysis included measurement of agar redox potential and root alcohol dehydrogenase (ADH) activity, localization, and expression. ADH activity increased by 89% as a result of spaceflight exposure for both CHROMEX-03 and -05 experiments, and ADH RNase protection assays revealed a 136% increase in ADH mRNA. The increase in ADH activity associated with the spaceflight roots was realized by a 28% decrease in oxygen availability in a ground-based study; however, no reduction in redox potential was observed in measurements of the spaceflight bulk agar. Spaceflight exposure appears to effect a hypoxic response in the roots of agar-grown plants that may be caused by changes in gravity-mediated fluid and/or gas behavior.

Cardiovascular and sympathetic neural responses to handgrip and cold pressor stimuli in humans before, during and after spaceflight

NASA Technical Reports Server (NTRS)

Fu, Qi; Levine, Benjamin D.; Pawelczyk, James A.; Ertl, Andrew C.; Diedrich, Andre; Cox, James F.; Zuckerman, Julie H.; Ray, Chester A.; Smith, Michael L.; Iwase, Satoshi;

Human Spaceflight The Kennedy Legacy

NASA Image and Video Library

2011-05-25

Musician Herbie Hancock bows to the audience after perfrorming during a program commemorating Human Spaceflight and the Kennedy Legacy, Wednesday, May 25, 2011, in the concert hall at the John F. Kennedy Center for the Performing Arts in Washington. The event marked the 50th Anniversary of President John F. Kennedy's Special Message to the Congress on Urgent National Needs in which he stated "landing a man on the moon and returning him safely to earth". Photo Credit: (NASA/Paul E. Alers)

Human Spaceflight The Kennedy Legacy

NASA Image and Video Library

2011-05-25

Musician Herbie Hancock plays a piece on the piano during a program commemorating Human Spaceflight and the Kennedy Legacy, Wednesday, May 25, 2011, in the concert hall at the John F. Kennedy Center for the Performing Arts in Washington. The event marked the 50th Anniversary of President John F. Kennedy's Special Message to the Congress on Urgent National Needs in which he stated "landing a man on the moon and returning him safely to earth". Photo Credit: (NASA/Paul E. Alers)

The Effect of Spaceflight on Growth of Ulocladium chartarum Colonies on the International Space Station

PubMed Central

Gomoiu, Ioana; Chatzitheodoridis, Elias; Vadrucci, Sonia; Walther, Isabelle

2013-01-01

The objectives of this 14 days experiment were to investigate the effect of spaceflight on the growth of Ulocladium chartarum, to study the viability of the aerial and submerged mycelium and to put in evidence changes at the cellular level. U. chartarum was chosen for the spaceflight experiment because it is well known to be involved in biodeterioration of organic and inorganic substrates covered with organic deposits and expected to be a possible contaminant in Spaceships. Colonies grown on the International Space Station (ISS) and on Earth were analysed post-flight. This study clearly indicates that U. chartarum is able to grow under spaceflight conditions developing, as a response, a complex colony morphotype never mentioned previously. We observed that spaceflight reduced the rate of growth of aerial mycelium, but stimulated the growth of submerged mycelium and of new microcolonies. In Spaceships and Space Stations U. chartarum and other fungal species could find a favourable environment to grow invasively unnoticed in the depth of surfaces containing very small amount of substrate, posing a risk factor for biodegradation of structural components, as well as a direct threat for crew health. The colony growth cycle of U. chartarum provides a useful eukaryotic system for the study of fungal growth under spaceflight conditions. PMID:23637980

Alterations in the heart rate and activity rhythms of three orbital astronauts on a space mission.

PubMed

Liu, Zhizhen; Wan, Yufeng; Zhang, Lin; Tian, Yu; Lv, Ke; Li, Yinghui; Wang, Chunhui; Chen, Xiaoping; Chen, Shanguang; Guo, Jinhu

2015-01-01

Environmental factors in space are dramatically different from those on Earth. The spaceflight environment has been known to influence human physiology and behavior on orbital missions. In this study, we investigated alterations in the diurnal rhythms of activity and heart rate of three Chinese astronauts on a space mission. An analysis of the heart rate data showed a significant decrease in heart rate amplitudes during flight in all three subjects. The heart rate amplitudes of all the three astronauts were significantly dampened during flight, and the minimum as well as the maximum value of heart rate increased after flight. A phase shift in heart rate was observed in one of the three astronauts after flight. These results demonstrate the influence of spaceflight on heart physiology and function. In addition, a significant decrease in body trunk activity and rhythmicity occurred during flight, demonstrating that the spaceflight environment disturbs motion adaptation and diurnal activity rhythms. Copyright © 2015 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Microbiome and bacterial translocation in cirrhosis.

PubMed

Gómez-Hurtado, Isabel; Such, José; Francés, Rubén

2016-12-01

Qualitative and quantitative changes in gut microbiota play a very important role in cirrhosis. Humans harbour around 100 quintillion gut bacteria, thus representing around 10 times more microbial cells than eukaryotic ones. The gastrointestinal tract is the largest surface area in the body and it is subject to constant exposure to these living microorganisms. The existing symbiosis, proven by the lack of proinflammatory response against commensal bacteria, implies the presence of clearly defined communication lines that contribute to the maintenance of homeostasis of the host. Therefore, alterations of gut flora seem to play a role in the pathogenesis and progress of multiple liver and gastrointestinal diseases. This has made its selective modification into an area of high therapeutic interest. Bacterial translocation is defined as the migration of bacteria or bacterial products from the intestines to the mesenteric lymph nodes. It follows that alteration in gut microbiota have shown importance, at least to some extent, in the pathogenesis of several complications arising from terminal liver disease, such as hepatic encephalopathy, portal hypertension and spontaneous bacterial peritonitis. This review sums up, firstly, how liver disease can alter the common composition of gut microbiota, and secondly, how this alteration contributes to the development of complications in cirrhosis. Copyright © 2015 Elsevier España, S.L.U., AEEH y AEG. All rights reserved.

Fastener Retention Requirements and Practices in Spaceflight Hardware

NASA Technical Reports Server (NTRS)

Dasgupta, Rajib

2004-01-01

This presentation reviews the requirements for safety critical fasteners in spaceflight hardware. Included in the presentation are design guidelines and information for Locking Helicoils, key locked inserts and thinwalled inserts, self locking screws and bolts. locknuts, and a locking adhesives, Loctite and Vibratite.

Does Simulated Spaceflight Modify Epigenetic Status During Bone Remodeling?

NASA Technical Reports Server (NTRS)

Thomas, Nicholas J.; Stevick, Rebecca J.; Tran, Luan H.; Nalavadi, Mohit O.; Almeida, Eduardo A.C.; Globus, Ruth K.; Alwood, Joshua S.

2015-01-01

Little is known about the effects of spaceflight conditions on epigenetics. The term epigenetics describes changes to the genome that can affect expression of a gene without changes to the sequence of DNA. Epigenetic processes are thought to underlie cellular differentiation, where transcription of specific genes occurs in response to key stimuli, and may be heritable - passing from one cell to its daughter cell. We hypothesize that the mechanical environment during spaceflight, namely microgravity-induced weightlessness or exercise regulate gene expression in the osteoblast-lineage cells both to control bone formation by osteoblasts and bone resorption by osteoclasts, which continually shapes bone structure throughout life. Similarly we intend to evaluate how radiation regulates these same bone cell activity and differentiation related genes. We further hypothesize that the regulation in bone cell gene expression is at least partially controlled through epigenetic mechanisms of methylation or small non-coding RNA (microRNAs). We have acquired preliminary data suggesting that global genome methylation is modified in response to axial compression of the tibia - a model of exercise. We intend to pursue these hypotheses wherein we will evaluate changes in gene expression and, congruently, changes in epigenetic state in bones from mice subjected to the aforementioned conditions: hindlimb unloading to simulate weightlessness, axial compression of the tibia, or radiation exposure in order to gain insight into the role of epigenetics in spaceflight-induced bone loss.

History of suborbital spaceflight: medical and performance issues.

PubMed

Campbell, Mark R; Garbino, Alejandro

2011-04-01

The development of manned sub-orbital commercial space vehicles is rapidly occurring and flight testing followed by operational flights will soon begin. The experience of manned suborbital spaceflight at the designated altitude (100 km/62.14 mi) is very limited--two Mercury-Redstone flights, two X-15 flights, one inadvertent Soyuz launch abort, and three recent SpaceShipOne flights, with only 15 min of critical flight time each. All indications were that the sequence of acceleration-weightlessness-deceleration was well tolerated with minimal neurovestibular dysfunction. However, there are some indications that distraction and spatial disorientation did occur. Vertigo on transition from the boost phase to weightlessness was reported on most high-altitude X-15 flights. +Gz tolerance to re-entry deceleration forces (as high as 6 + Gz) after 4 min of weightlessness is still unknown. Only further suborbital spaceflight experience will clarify if pilot performance will be affected.

Summary of biological spaceflight experiments with cells.

PubMed

Dickson, K J

1991-07-01

Numerous biological experiments with cells have been conducted in space, and the importance of these experiments and this area of study is continually becoming evident. This contribution is a compilation of available information about spaceflight experiments with cells for the purpose of providing a single source of information for those interested in space gravitational cell biology. Experiments focused on a study of the effects of gravity and its absence on cells, cell function, and basic cellular processes have been included. Experiments include those involving viruses, bacteriophage, unicellular organisms, lower fungi, and animal and plant cell and tissue cultures, but exclude experiments with cells that were carried on a flight as part of a whole organism and later removed for study, and experiments with fertilized eggs. In addition, experiments in biotechnology, in which the microgravity environment is employed to study cell purification, cell fusion, protein crystallization, and similar processes, have not been included. Spaceflight experiments conducted by scientists from the U.S., U.S.S.R., and other countries and flown onboard sounding rockets (TEXUS, MAXUS, Consort), biosatellites (Biosatellite II, Cosmos), and various crewed spacecraft including the space shuttle (STS) and Soyuz, and space stations (Salyut, Mir) have been included, as well as high altitude balloon flights. Balloon flights are not spaceflights but can and are used as controls for the effects of space radiation, since organisms carried on balloons may be exposed to some of the same radiation as those taken into space, yet continue to be exposed to Earth's gravitational force. Parabolic flights on aircraft during which periods of microgravity of less than a minute are achieved have arbitrarily been excluded, because even though numerous experiments have been conducted, few results have been published.

Molecular Mechanisms of Circadian Regulation During Spaceflight

NASA Technical Reports Server (NTRS)

Zanello, S. B.; Boyle, R.

2012-01-01

The physiology of both vertebrates and invertebrates follows internal rhythms coordinated in phase with the 24-hour daily light cycle. This circadian clock is governed by a central pacemaker, the suprachiasmatic nucleus (SCN) in the brain. However, peripheral circadian clocks or oscillators have been identified in most tissues. How the central and peripheral oscillators are synchronized is still being elucidated. Light is the main environmental cue that entrains the circadian clock. Under the absence of a light stimulus, the clock continues its oscillation in a free-running condition. In general, three functional compartments of the circadian clock are defined. The vertebrate retina contains endogenous clocks that control many aspects of retinal physiology, including retinal sensitivity to light, neurohormone synthesis (melatonin and dopamine), rod disk shedding, signalling pathways and gene expression. Neurons with putative local circadian rhythm generation are found among all the major neuron populations in the mammalian retina. In the mouse, clock genes and function are more localized to the inner retinal and ganglion cell layers. The photoreceptor, however, secrete melatonin which may still serve a an important circadian signal. The reception and transmission of the non-visual photic stimulus resides in a small subpopulation (1-3%) or retinal ganglion cells (RGC) that express the pigment melanopsin (Opn4) and are called intrisically photoreceptive RGC (ipRGC). Melanopsin peak absorption is at 420 nm and all the axons of the ipRGC reach the SCN. A common countermeasure for circadian re-entrainment utilizes blue-green light to entrain the circadian clock and mitigate the risk of fatigue and health and performance decrement due to circadian rhythm disruption. However, an effective countermeasure targeting the photoreceptor system requires that the basic circadian molecular machinery remains intact during spaceflight. We hypothesize that spaceflight may affect ip

Effects of spaceflight on rhesus quadrupedal locomotion after return to 1G

NASA Technical Reports Server (NTRS)

Recktenwald, M. R.; Hodgson, J. A.; Roy, R. R.; Riazanski, S.; McCall, G. E.; Kozlovskaya, I.; Washburn, D. A.; Fanton, J. W.; Edgerton, V. R.; Rumbaugh, D. M. (Principal Investigator)

1999-01-01

Effects of spaceflight on Rhesus quadrupedal locomotion after return to 1G. Locomotor performance, activation patterns of the soleus (Sol), medial gastrocnemius (MG), vastus lateralis (VL), and tibialis anterior (TA) and MG tendon force during quadrupedal stepping were studied in adult Rhesus before and after 14 days of either spaceflight (n = 2) or flight simulation at 1G (n = 3). Flight simulation involved duplication of the spaceflight conditions and experimental protocol in a 1G environment. Postflight, but not postsimulation, electromyographic (EMG) recordings revealed clonus-like activity in all muscles. Compared with preflight, the cycle period and burst durations of the primary extensors (Sol, MG, and VL) tended to decrease postflight. These decreases were associated with shorter steps. The flexor (TA) EMG burst duration postflight was similar to preflight, whereas the burst amplitude was elevated. Consequently, the Sol:TA and MG:TA EMG amplitude ratios were lower following flight, reflecting a "flexor bias." Together, these alterations in mean EMG amplitudes reflect differential adaptations in motor-unit recruitment patterns of flexors and extensors as well as fast and slow motor pools. Shorter cycle period and burst durations persisted throughout the 20-day postflight testing period, whereas mean EMG returned to preflight levels by 17 days postflight. Compared with presimulation, the simulation group showed slight increases in the cycle period and burst durations of all muscles. Mean EMG amplitude decreased in the Sol, increased in the MG and VL, and was unchanged in the TA. Thus adaptations observed postsimulation were different from those observed postflight, indicating that there was a response unique to the microgravity environment, i.e., the modulations in the nervous system controlling locomotion cannot merely be attributed to restriction of movement but appear to be the result of changes in the interpretation of load-related proprioceptive feedback

Adaptations of young adult rat cortical bone to 14 days of spaceflight

NASA Technical Reports Server (NTRS)

Vailas, A. C.; Vanderby, R., Jr.; Martinez, D. A.; Ashman, R. B.; Ulm, M. J.; Grindeland, R. E.; Durnova, G. N.; Kaplanskii, A.

1992-01-01

To determine whether mature humeral cortical bone would be modified significantly by an acute exposure to weightlessness, adult rats (110 days old) were subjected to 14 days of microgravity on the COSMOS 2044 biosatellite. There were no significant changes in peak force, stiffness, energy to failure, and displacement at failure in the flight rats compared with ground-based controls. Concentrations and contents of hydroxyproline, calcium, and mature stable hydroxylysylpyridinoline and lysylpyridinoline collagen cross-links remained unchanged after spaceflight. Bone lengths, cortical and endosteal areas, and regionl thicknesses showed no significant differences between flight animals and ground controls. The findings suggest that responsiveness of cortical bone to microgravity is less pronounced in adult rats than in previous spaceflight experiments in which young growing animals were used. It is hypothesized that 14 days of spaceflight may not be sufficient to impact the biochemical and biomechanical properties of cortical bone in the mature rat skeleton.

The Challenges and Achievements in 50 Years of Human Spaceflight

NASA Astrophysics Data System (ADS)

Hawley, Steven A.

2012-01-01

On April 12, 1961 the era of human spaceflight began with the orbital flight of Cosmonaut Yuri Gagarin. On May 5, 1961 The United States responded with the launch of Alan Shepard aboard Freedom 7 on the first flight of Project Mercury. The focus of the first 20 years of human spaceflight was developing the fundamental operational capabilities and technologies required for a human mission to the Moon. The Mercury and Gemini Projects demonstrated launch and entry guidance, on-orbit navigation, rendezvous, extravehicular activity, and flight durations equivalent to a round-trip to the Moon. Heroes of this epoch included flight directors Chris Kraft, Gene Kranz, and Glynn Lunney along with astronauts like John Young, Jim Lovell, Tom Stafford, and Neil Armstrong. The "Race to the Moon” was eventually won by the United States with the landing of Apollo 11 on July 20, 1969. The Apollo program was truncated at 11 missions and a new system, the Space Shuttle, was developed which became the focus of the subsequent 30 years. Although never able to meet the flight rate or cost promises made in the 1970s, the Shuttle nevertheless left a remarkable legacy of accomplishment. The Shuttle made possible the launch and servicing of the Hubble Space Telescope and diverse activities such as life science research and classified national security missions. The Shuttle launched more than half the mass ever put into orbit and its heavy-lift capability and large payload bay enabled the on-orbit construction of the International Space Station. The Shuttle also made possible spaceflight careers for scientists who were not military test pilots - people like me. In this talk I will review the early years of spaceflight and share my experiences, including two missions with HST, from the perspective of a five-time flown astronaut and a senior flight operations manager.

The elements of a commercial human spaceflight safety reporting system

NASA Astrophysics Data System (ADS)

Christensen, Ian

2017-10-01

In its report on the SpaceShipTwo accident the National Transportation Safety Board (NTSB) included in its recommendations that the Federal Aviation Administration (FAA) ;in collaboration with the commercial spaceflight industry, continue work to implement a database of lessons learned from commercial space mishap investigations and encourage commercial space industry members to voluntarily submit lessons learned.; In its official response to the NTSB the FAA supported this recommendation and indicated it has initiated an iterative process to put into place a framework for a cooperative safety data sharing process including the sharing of lessons learned, and trends analysis. Such a framework is an important element of an overall commercial human spaceflight safety system.

Dietary Intake Can Predict and Protect Against Changes in Bone Metabolism during Spaceflight and Recovery (Pro K)

NASA Technical Reports Server (NTRS)

Smith, Scott M.; Zwart, S. R.; Shackelford, L.; Heer, M.

2009-01-01

Bone loss is not only a well-documented effect of spaceflight on astronauts, but also a condition that affects millions of men and women on Earth each year. Many countermeasures aimed at preventing bone loss during spaceflight have been proposed, and many have been evaluated to some degree. To date, those showing potential have focused on either exercise or pharmacological interventions, but none have targeted dietary intake alone as a factor to predict or minimize bone loss during spaceflight. The "Dietary Intake Can Predict and Protect against Changes in Bone Metabolism during Spaceflight and Recovery" investigation ("Pro K") is one of the first inflight evaluations of a dietary countermeasure to lessen bone loss of astronauts. This protocol will test the hypothesis that the ratio of acid precursors to base precursors (specifically animal protein to potassium) in the diet can predict directional changes in bone mineral during spaceflight and recovery. The ratio of animal protein to potassium in the diet will be controlled for multiple short (4-day) periods before and during flight. Based on multiple sets of bed rest data, we hypothesize that a higher ratio of the intake of animal protein to the intake of potassium will yield higher concentrations of markers of bone resorption and urinary calcium excretion during flight and during recovery from bone mineral loss after long-duration spaceflight.

The sympathetic nervous system and the physiologic consequences of spaceflight: a hypothesis

NASA Technical Reports Server (NTRS)

Robertson, D.; Convertino, V. A.; Vernikos, J.

1994-01-01

Many of the physiologic consequences of weightlessness and the cardiovascular abnormalities on return from space could be due, at least in part, to alterations in the regulation of the autonomic nervous system. In this article, the authors review the rationale and evidence for an autonomic mediation of diverse changes that occur with spaceflight, including the anemia and hypovolemia of weightlessness and the tachycardia and orthostatic intolerance on return from space. This hypothesis is supported by studies of two groups of persons known to have low catecholamine levels: persons subjected to prolonged bedrest and persons with syndromes characterized by low circulating catecholamines (Bradbury-Eggleston syndrome and dopamine beta-hydroxylase deficiency). Both groups exhibit the symptoms mentioned. The increasing evidence that autonomic mechanisms underlie many of the physiologic consequences of weightlessness suggests that new pharmacologic approaches (such as administration of beta-blockers and/or sympathomimetic amines) based on these findings may attenuate these unwanted effects.

Investigation of the Influence of Microgravity on Transport Mechanisms in a Virtual Spaceflight Chamber: A Ground-Based Program

NASA Technical Reports Server (NTRS)

Trolinger, James D.; Lal, Ravindra B.; Rangel, Roger; Witherow, William; Rogers, Jan

2001-01-01

The IML-1 Spaceflight produced over 1000 holograms of a well-defined particle field in the low g Spacelab environment; each containing as much as 1000 megabytes of information. This project took advantage of these data and the concept of holographic "virtual" spaceflight to advance the understanding of convection in the space shuttle environment, g-jitter effects on crystal growth, and complex transport phenomena in low Reynolds number flows. The first objective of the proposed work was to advance the understanding of microgravity effects on crystal growth. This objective was achieved through the use of existing holographic data recorded during the IML-1 Spaceflight. The second objective was to design a spaceflight experiment that exploits the "virtual space chamber concept" in which holograms of space chambers can provide a virtual access to space. This led to a flight definition project, which is now underway under a separate contract known as SHIVA, Spaceflight Holography Investigation in a Virtual Apparatus.

2014 Summer Series - Josh Alwood - To the Bone: Spaceflight and the Skeletal System

NASA Image and Video Library

2014-08-05

During spaceflight, astronauts experience weightlessness and are exposed to novel types of radiation. These environmental conditions may contribute to bone loss and reduction of structural integrity of the skeleton, which have negative implications for long-duration missions. The aim of this talk is to provide an overview of skeletal changes observed both in astronauts and in ground-based models of spaceflight, focusing on the fundamental biology and the prevention of deleterious skeletal changes.

Altered gravity downregulates aquaporin-1 protein expression in choroid plexus.

PubMed

Masseguin, C; Corcoran, M; Carcenac, C; Daunton, N G; Güell, A; Verkman, A S; Gabrion, J

2000-03-01

Aquaporin-1 (AQP1) is a water channel expressed abundantly at the apical pole of choroidal epithelial cells. The protein expression was quantified by immunocytochemistry and confocal microscopy in adult rats adapted to altered gravity. AQP1 expression was decreased by 64% at the apical pole of choroidal cells in rats dissected 5.5-8 h after a 14-day spaceflight. AQP1 was significantly overexpressed in rats readapted for 2 days to Earth's gravity after an 11-day flight (48% overshoot, when compared with the value measured in control rats). In a ground-based model that simulates some effects of weightlessness and alters choroidal structures and functions, apical AQP1 expression was reduced by 44% in choroid plexus from rats suspended head down for 14 days and by 69% in rats suspended for 28 days. Apical AQP1 was rapidly enhanced in choroid plexus of rats dissected 6 h after a 14-day suspension (57% overshoot, in comparison with control rats) and restored to the control level when rats were dissected 2 days after the end of a 14-day suspension. Decreases in the apical expression of choroidal AQP1 were also noted in rats adapted to hypergravity in the NASA 24-ft centrifuge: AQP1 expression was reduced by 47% and 85% in rats adapted for 14 days to 2 G and 3 G, respectively. AQP1 is downregulated in the apical membrane of choroidal cells in response to altered gravity and is rapidly restored after readaptation to normal gravity. This suggests that water transport, which is partly involved in the choroidal production of cerebrospinal fluid, might be decreased during spaceflight and after chronic hypergravity.

Effect of spaceflight on isoflavonoid accumulation in etiolated soybean seedlings

NASA Technical Reports Server (NTRS)

Levine, L. H.; Levine, H. G.; Stryjewski, E. C.; Prima, V.; Piastuch, W. C.; Sager, J. S. (Principal Investigator)

2001-01-01

In order to explore the potential impact of microgravity on flavonoid biosynthesis, we examined isoflavonoid levels in soybean (Glycine max) tissues generated under both spaceflight and clinorotation conditions. A 6-day Space Shuttle-based microgravity exposure resulted in enhanced accumulation of isoflavone glycosides (daidzin, 6"-O-malonyl-7-O-glucosyl daidzein, genistin, 6"-O-malonyl-7-O-glucosyl genistein) in hypocotyl and root tissues, but reduced levels in cotyledons (relative to 1g controls on Earth). Soybean seedlings grown on a horizontally rotating clinostat for 3, 4 and 5 days exhibited (relative to a vertical clinorotation control) an isoflavonoid accumulation pattern similar to the space-grown tissues. Elevated isoflavonoid levels attributable to the clinorotation treatment were transient, with the greatest increase observed in the three-day-treated tissues and smaller increases in the four- and five-day-treated tissues. Differences between stresses presented by spaceflight and clinorotation and the resulting biochemical adaptations are discussed, as is whether the increase in isoflavonoid concentrations were due to differential rates of development under the "gravity" treatments employed. Results suggest that spaceflight exposure does not impair isoflavonoid accumulation in developing soybean tissues and that isoflavonoids respond positively to microgravity as a biochemical strategy of adaptation.

Inactivation of the Ecs ABC transporter of Staphylococcus aureus attenuates virulence by altering composition and function of bacterial wall.

PubMed

Jonsson, Ing-Marie; Juuti, Jarmo T; François, Patrice; AlMajidi, Rana; Pietiäinen, Milla; Girard, Myriam; Lindholm, Catharina; Saller, Manfred J; Driessen, Arnold J M; Kuusela, Pentti; Bokarewa, Maria; Schrenzel, Jacques; Kontinen, Vesa P

2010-12-02

Ecs is an ATP-binding cassette (ABC) transporter present in aerobic and facultative anaerobic gram-positive Firmicutes. Inactivation of Bacillus subtilis Ecs causes pleiotropic changes in the bacterial phenotype including inhibition of intramembrane proteolysis. The molecule(s) transported by Ecs is (are) still unknown. In this study we mutated the ecsAB operon in two Staphylococcus aureus strains, Newman and LS-1. Phenotypic and functional characterization of these Ecs deficient mutants revealed a defect in growth, increased autolysis and lysostaphin sensitivity, altered composition of cell wall proteins including the precursor form of staphylokinase and an altered bacterial surface texture. DNA microarray analysis indicated that the Ecs deficiency changed expression of the virulence factor regulator protein Rot accompanied by differential expression of membrane transport proteins, particularly ABC transporters and phosphate-specific transport systems, protein A, adhesins and capsular polysaccharide biosynthesis proteins. Virulence of the ecs mutants was studied in a mouse model of hematogenous S. aureus infection. Mice inoculated with the ecs mutant strains developed markedly milder infections than those inoculated with the wild-type strains and had consequently lower mortality, less weight loss, milder arthritis and decreased persistence of staphylococci in the kidneys. The ecs mutants had higher susceptibility to ribosomal antibiotics and plant alkaloids chelerythrine and sanguinarine. Our results show that Ecs is essential for staphylococcal virulence and antimicrobial resistance probably since the transport function of Ecs is essential for the normal structure and function of the cell wall. Thus targeting Ecs may be a new approach in combating staphylococcal infection.

How Will Astronauts Stay Fit during Long Spaceflights?

ERIC Educational Resources Information Center

Pine, Devera

1989-01-01

Astronauts on lengthy spaceflights must exercise regularly to forestall muscle atrophy and bone loss, but exercise presents unique problems in a weightless environment. All exercise equipment must have a harness or seat belt. Soviet and NASA space exercise plans and experimental ideas are discussed. (Author/SM)

Plant reproduction in spaceflight environments

NASA Technical Reports Server (NTRS)

Musgrave, M. E.; Kuang, A.; Porterfield, D. M.

1997-01-01

Because plant reproduction is a complex developmental process there are many possible sites of perturbation by the unusual environments of orbital spacecraft. Previous long-duration experiments on Soviet platforms shared features of slowed development through the vegetative stage of plant growth and aborted reproductive function. Our goal has been to understand how special features of the spaceflight environment impact physiological function and reproductive development. In a series of short-duration experiments in the Shuttle mid-deck we studied early reproductive development in Arabidopsis thaliana. Pollen and ovule development aborted at an early stage in the first experiment on STS-54 which utilized closed plant growth chambers. Post-flight analysis suggested that the plants may have been carbon dioxide limited. Subsequent experiments utilized carbon dioxide enrichment (on STS-51) and cabin air flow-through with an air exchange system (on STS-68). Both modifications allowed pollen and ovule development to occur normally on orbit, and full reproductive development up to the stage of an immature seed occurred on STS-68. However, analysis of plant roots from these experiments demonstrated a limitation in rootzone aeration in the spaceflight material that was not mitigated by these procedures. In the future, additional resources (crew time, upgraded flight hardware, and special platforms) will invite more elaborate, long-duration experimentation. On the ISS, a variable speed centrifuge and upgraded plant habitats will permit detailed experiments on the role of gravity in shaping the plant micro-environment, and what influence this plays during reproduction.

Evidence Report: Risk of Spaceflight Associated Neuro-ocular Syndrome (SANS)

NASA Technical Reports Server (NTRS)

Stenger, Michael B.; Tarver, William J.; Brunstetter, Tyson; Gibson, Charles Robert; Laurie, Steven S.; Lee, Stuart M. C.; Macias, Brandon R.; Mader, Thomas H.; Otto, Christian; Smith, Scott M.;

Effects of Spaceflight on Cells of Bone Marrow Origin

PubMed Central

Özçivici, Engin

2013-01-01

Once only a subject for science fiction novels, plans for establishing habitation on space stations, the Moon, and distant planets now appear among the short-term goals of space agencies. This article reviews studies that present biomedical issues that appear to challenge humankind for long-term spaceflights. With particularly focus on cells of bone marrow origin, studies involving changes in bone, immune, and red blood cell populations and their functions due to extended weightlessness were reviewed. Furthermore, effects of mechanical disuse on primitive stem cells that reside in the bone marrow were also included in this review. Novel biomedical solutions using space biotechnology will be required in order to achieve the goal of space exploration without compromising the functions of bone marrow, as spaceflight appears to disrupt homeostasis for all given cell types. Conflict of interest:None declared. PMID:24385745

Immune System Dysregulation and Herpesvirus Reactivation Persist During Long-Duration Spaceflight

NASA Technical Reports Server (NTRS)

Crucian, B. E.; Mehta, S.; Stowe, R. P.; Uchakin, P.; Quiriarte, H.; Pierson, D.; Sams, C. F.

2011-01-01

This poster presentation reviews a study that is designed to address immune system dysregulation and the risk to crewmembers in long duration exploration class missions. This study will address these objectives: (1) Determine the status of adaptive immunity physiological stress, viral immunity, latent herpesvirus reactivation in astronauts during 6 month missions to the International Space Station; (2) determine the clinical risk related to immune dysregulation for exploration class spaceflight; and (3) determine an appropriate monitoring strategy for spaceflight-associated immune dysfunction that could be used for the evaluation of countermeasures. The study anticipates 17 subjects, and for this presentation, (midpoint study data) 10 subjects are reviewed.

Soil bacterial community and functional shifts in response to altered snowpack in moist acidic tundra of northern Alaska

NASA Astrophysics Data System (ADS)

Ricketts, Michael P.; Poretsky, Rachel S.; Welker, Jeffrey M.; Gonzalez-Meler, Miquel A.

2016-09-01

. Bacterial functional potential was inferred using ancestral state reconstruction to approximate functional gene abundance, revealing a decreased abundance of genes required for soil organic matter (SOM) decomposition in the organic layers of the deep snow accumulation zones. These results suggest that predicted climate change scenarios may result in altered soil bacterial community structure and function, and indicate a reduction in decomposition potential, alleviated temperature limitations on extracellular enzymatic efficiency, or both. The fate of stored C in Arctic soils ultimately depends on the balance between these mechanisms.

Effects of Spaceflight on Bone: The Rat as an Animal Model for Human Bone Loss

NASA Technical Reports Server (NTRS)

Halloran, B.; Weider, T.; Morey-Holton, E.

1999-01-01

The loss of weight bearing during spaceflight results in osteopenia in humans. Decrements in bone mineral reach 3-10% after as little as 75-184 days in space. Loss of bone mineral during flight decreases bone strength and increases fracture risk. The mechanisms responsible for, and the factors contributing to, the changes in bone induced by spaceflight are poorly understood. The rat has been widely used as an animal model for human bone loss during spaceflight. Despite its potential usefulness, the results of bone studies performed in the rat in space have been inconsistent. In some flights bone formation is decreased and cancellous bone volume reduced, while in others no significant changes in bone occur. In June of 1996 Drs. T. Wronski, S. Miller and myself participated in a flight experiment (STS 78) to examine the effects of glucocorticoids on bone during weightlessness. Technically the 17 day flight experiment was flawless. The results, however, were surprising. Cancellous bone volume and osteoblast surface in the proximal tibial metaphysis were the same in flight and ground-based control rats. Normal levels of cancellous bone mass and bone formation were also detected in the lumbar vertebrae and femoral neck of flight rats. Furthermore, periosteal bone formation rate was found to be identical in flight and ground-based control rats. Spaceflight had little or no effect on bone metabolism! These results prompted us to carefully review the changes in bone observed in, and the flight conditions of previous spaceflight missions.

KENNEDY SPACE CENTER, FLA. - From left, Bob McLean, Southwest Texas State University; Valerie Cassanto, Instrumentation Technology Associates, Inc.; and Dennis Morrison, NASA Johnson Space Center, process one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

NASA Image and Video Library

2003-05-07

KENNEDY SPACE CENTER, FLA. - From left, Bob McLean, Southwest Texas State University; Valerie Cassanto, Instrumentation Technology Associates, Inc.; and Dennis Morrison, NASA Johnson Space Center, process one of the experiments carried on mission STS-107. Several experiments were found during the search for Columbia debris. Included in the Commercial ITA Biomedical Experiments payload on mission STS-107 are urokinase cancer research, microencapsulation of drugs, the Growth of Bacterial Biofilm on Surfaces during Spaceflight (GOBBSS), and tin crystal formation.

Spaceflight-induced Bone Loss: Countermeasures and Their Evaluations

NASA Technical Reports Server (NTRS)

Sibonga, Jean D.

2008-01-01

The learning objectives of this viewgraph presentation are to: (1) Understand the biomedical effects of spaceflight and their associated health risks. (2) Understand how the "Factor of Risk" for fracture can be calculated in the adult skeleton for space travel. and (3) Understand how various countermeasures [CMs] influence the Factor of Risk.

Evaluation of the nutrient-upgraded rodent food bar for rodent spaceflight experiments.

PubMed

Sun, Gwo-Shing; Tou, Janet C; Liittschwager, Kurt; Herrera, Anna M; Hill, Esther L; Girten, Beverly; Reiss-Bubenheim, Debra; Vasques, Marilyn

2010-01-01

Selection of an appropriate diet for rodent spaceflight experiments is critical and may have significant effects on mission results. The National Aeronautics and Space Administration (NASA) rodent food bar (RFB) was reformulated and designated as the nutrient-upgraded RFB (NuRFB). The objectives of this study were to determine whether the NuRFB nutrient formulation meets the 1995 National Research Council (NRC) nutrient recommendations and whether the NuRFB can be used for short-term (45-d) and long-term (90-d) spaceflight experiments. Nutrient and moisture analyses of the NuRFB were performed. Young (age 13-14 wk) male Sprague-Dawley rats (n=16/group) were individually caged and fed a diet treatment consisting of 1) NuRFB, 2) RFB, or 3) modified AIN-93G containing 4% instead of the 7% fat for 45- or 90-d. At the end of the study, organs were weighted, and serum clinical chemistry indicators of organ function and hematologic measurements were determined. Chemical analysis of the diet ingredients showed that the NuRFB met the 1995 NRC nutrient recommendations for rats. Subsequent animal feeding studies showed that NuRFB was comparable to RFB and modified AIN-93G for supporting rat growth and body weight maintenance. In addition, the safety of the NuRFB for use as a spaceflight diet was indicated by the absence of changes in organ weight or function. Based on the study results, the NuRFB performed similarly to the RFB and met the criteria necessary for short-term and long-term rodent spaceflight experiments. Published by Elsevier Inc.

Camera aboard 'Friendship 7' photographs John Glenn during spaceflight

NASA Technical Reports Server (NTRS)

1962-01-01

A camera aboard the 'Friendship 7' Mercury spacecraft photographs Astronaut John H. Glenn Jr. during the Mercury-Atlas 6 spaceflight (00302-3); Photographs Glenn as he uses a photometer to view the sun during sunsent on the MA-6 space flight (00304).

Review of Human Cognitive Performance in Spaceflight

NASA Technical Reports Server (NTRS)

Strangman, Gary; Bevan, Gary

2012-01-01

Human space exploration is inherently hazardous, particularly for lon g duration (LD) missions (22 days or longer). Maintenance of cognitive functioning is essential, but flight environments pose numerous pote ntial risks to the brain and cognitive performance (eg, radiation, to xins, chronic stress, sleep deprivation, hypercarbia, fluid shifts, h ormone imbalances, and injury). There have been persistent anecdotal reports of cognitive deficits during missions, but an up?-to-date rev iew of the evidence for such changes has remained unavailable. Method s: We identified and reviewed English language publications found via electronic searches in PubMed, PsycInfo, Inspec, the NASA Technical Report Server, and the Defense Technical Information Center, plus rec ursive searches of publication bibliographies. Search terms included the word cognition, cognitive, or performance along with spaceflight, flight, mission, or closely related terms. Results: Inter?-study variability precluded meta?-analysis. Some 32 published studies involving cognitive assessment during spaceflight were identified, involving a total of 110 participants (mean: 3.4 participants per study). The lo ngest?-duration study spanned 438 days, with six additional studies i nvolving flight durations of 90 days, and 11 more studies involved fl ight durations exceeding 21 days. The available evidence failed to st rongly support or refute the existence of cognitive deficits in LD sp aceflight, in part due to inadequate power or control conditions. Evi dence of increased variability in cognitive performance during spacef light, both within and between individuals, was common. Discussion: T hese results represent a negative finding based on small numbers of s ubjects for any given cognitive function. The increased variability within and (particularly) between individuals highlights the potential danger of generalizing from case studies. A mismatch therefore remain s between anecdotal reports describing

Spaceflight and protein metabolism, with special reference to humans

NASA Technical Reports Server (NTRS)

Stein, T. P.; Gaprindashvili, T.

1994-01-01

Human space missions have shown that human spaceflight is associated with a loss of body protein. Specific changes include a loss of lean body mass, decreased muscle mass in the calves, decreased muscle strength, and changes in plasma proteins and amino acids. The major muscle loss is believed to be associated with the antigravity (postural) muscle. The most significant loss of protein appears to occur during the first month of flight. The etiology is believed to be multifactorial with contributions from disuse atrophy, undernutrition, and a stress type of response. This article reviews the results of American and Russian space missions to investigate this problem in humans, monkeys, and rats. The relationship of the flight results with ground-based models including bedrest for humans and hindlimb unweighting for rats is also discussed. The results suggest that humans adapt to spaceflight much better than either monkeys or rats.

A platform for real-time online health analytics during spaceflight

NASA Astrophysics Data System (ADS)

McGregor, Carolyn

Monitoring the health and wellbeing of astronauts during spaceflight is an important aspect of any manned mission. To date the monitoring has been based on a sequential set of discontinuous samplings of physiological data to support initial studies on aspects such as weightlessness, and its impact on the cardiovascular system and to perform proactive monitoring for health status. The research performed and the real-time monitoring has been hampered by the lack of a platform to enable a more continuous approach to real-time monitoring. While any spaceflight is monitored heavily by Mission Control, an important requirement within the context of any spaceflight setting and in particular where there are extended periods with a lack of communication with Mission Control, is the ability for the mission to operate in an autonomous manner. This paper presents a platform to enable real-time astronaut monitoring for prognostics and health management within space medicine using online health analytics. The platform is based on extending previous online health analytics research known as the Artemis and Artemis Cloud platforms which have demonstrated their relevance for multi-patient, multi-diagnosis and multi-stream temporal analysis in real-time for clinical management and research within Neonatal Intensive Care. Artemis and Artemis Cloud source data from a range of medical devices capable of transmission of the signal via wired or wireless connectivity and hence are well suited to process real-time data acquired from astronauts. A key benefit of this platform is its ability to monitor their health and wellbeing onboard the mission as well as enabling the astronaut's physiological data, and other clinical data, to be sent to the platform components at Mission Control at each stage when that communication is available. As a result, researchers at Mission Control would be able to simulate, deploy and tailor predictive analytics and diagnostics during the same spaceflight for

Reduction of Dietary Acid Load as a Potential Countermeasure for Bone Loss Associated with Spaceflight

NASA Technical Reports Server (NTRS)

Zwart, S. R.; Watts, S. M.; Sams, C. F.; Whitson, P. A.; Smith, S. M.

2006-01-01

In several studies we tested the concepts that diet can alter acid-base balance and that reducing the dietary acid load has a positive effect on maintenance of bone. In study 1, (n = 11, 60-90 d bed rest), the renal acid load of the diet was estimated from its chemical composition, and was positively correlated with urinary markers of bone resorption (P less than 0.05); that is, the greater the acid load, the greater the excretion of bone resorption markers. In study 2, in males (n = 8, 30 d bed rest), an estimate of the ratio of nonvolatile acid precursors to base precursors in the diet was positively correlated (P less than 0.05) with markers of bone resorption. In study 3, for 28 d subjects received either a placebo (n = 6) or an essential amino acid supplement (n = 7) that included methionine, a known acid precursor. During bed rest (28 d), urinary calcium was greater than baseline levels in the supplemented group but not the control group (P less than 0.05), and in the supplemented group, urinary pH decreased (P less than 0.05). In study 4, less bone resorption occurred in space crew members who received potassium citrate (n = 6) during spaceflight of 4-6 months than in crew members who received placebo or were not in the study (n = 8) (P less than 0.05). Reducing acid load has the potential to mitigate increased bone resorption during spaceflight, and may serve as a bone loss countermeasure.