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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9

Rat growth during chronic centrifugation

Female weanling rats were chronically centrifuged at 4.15 G with controls at terrestrial gravity. Samples were sacrificed for body composition studies at 0, 28, 63, 105 and 308 days of centrifugation. The centrifuged group approached a significantly lower mature body mass than the controls (251 and 318g) but the rate of approach was the same in both groups. Retirement to 1G on the 60th day resulted in complete recovery. Among individual components muscle, bone, skin, CNS, heart, kidneys, body water and body fat were changed in the centrifuged group. However, an analysis of the growth of individual components relative to growth of the total fat-free compartment revealed that only skin (which increased in mass) was responding to centrifugation per se.

Pitts, G. C.↗

Acid-base homeostasis in the human system

Acid-base regulation is a cooperative phenomena in vivo with body fluids, extracellular and intracellular buffers, lungs, and kidneys all playing important roles. The present account is much too brief to be considered a review of present knowledge of these regulatory systems, and should be viewed, instead, as a guide to the elements necessary to construct a simple model of the mutual interactions of the acid-base regulatory systems of the body.

White, R. J.↗

Mechanism of disorder of plastic processes in tissue during prolonged hypokinesia

The subcellular structures of the myocardium, skeletal muscles, liver and kidneys of adult rats subjected to hypokinesia (in immobilization chambers) for 15, 30, and 45 days were studied. An anabolyser (retabolil) and vitamin D (a Ca metabolism regulator) were administered to two groups of rats. On the second week of hypokinesia, inhibition of synthesis processes was observed. Administration of retabolil increased protein synthesis both in the normal and hypokinesia-subjected rats; however, in the latter group, synthesis did not completely normalize, especially in the myocardium. Administration of vitamin D also stimulated protein synthesis, apparently by normalizing Ca tissue metabolism. The combined action of both preparations was the most effective in normalizing protein synthesis intensity. It was concluded that inhibition of synthesis is related to weakening of hormone synthesis induction and disorder of Ca metabolism.

Makarov, G. A.↗

Free amino acids of the blood and some organs in hypokinesia

The metabolic fund of amino acids of the blood and tissues of rats under hypokinesia was investigated. The content of free amino acids was determined for the liver, kidney, brain, and the skeletal and cardiac muscles after established periods of hypokinesia. It was found that the total content of free amino acids in the experimental animals was, on the average 19 percent lower than in the controls. The results of the quantity of individual compounds indicate that the level of some were reduced while others were increased. It was also found that there was an unequal content of individual amino acids in the different tissues.

Kurtser, B. M.↗

Temperature and frequency dependence of ultrasonic attenuation in selected tissues

Ultrasonic attenuation over the frequency range of 1.5-10 MHz has been measured as a function of temperature for porcine liver, backfat, kidney and spleen as well as for a single specimen of human liver. The attenuation in these excised specimens increases nearly linearly with frequency. Over the temperature range of approximately 4-37 C the attenuation decreases with increasing temperature for most soft tissue studied.

Gammell, P. M.↗

Orthostasis test in the practice of the cardiologist

The orthostasis test makes it possible to evaluate neurohumoral regulation and reaction of the circulatory system and to detect changes in the function of a number of internal organs (especially the kidney). Simultaneous recording of the ECG in an orthostatic position despite nonspecificity, makes it possible to detect hidden damage (organic or metabolic) or increased sensitivity of the myocardium to stressor sympathetico-adrenal effects, stability of therapeutic effect, and the action mechanism of a number of drugs.

Moskalenko, N. P.↗

Experiment K-316: Effects of weightlessness on body composition in the rat

Five male rats were dissected into three major compartments (musculo-skeletal system, skin, and pooled viscera) and compared with synchronous controls. The flight group show a 6.7% reduction in total body water probably attributable to a 36.2% reduction in the extracellular compartment, reductions of 6.6% in musculo-skeletal water and 17.2% in skin water, an apparent shift of some water from skin to viscera, and a 20% reduction in bone mineral mass. Among organ fresh masses there was a 7.5% increase in kidneys and a 14.0% decrease in spleen.

Ushakov, A. S.↗

Cyclic nucleotides in tissues during long-term hypokinesia

Male Wistar rates were kept hypokinetic by placing them in small containers for 22 days. Blood plasma cAMP content was subsequently found increased, and cGMP content decreased, in the experimental animals. Liver and thymus cAMP content was similar in the control and experimental animals. There was a 20 and 38% decrease of cAMP content in the kidneys and spleen, respectively. Hypokinesia's reduction of cyclic nucleotides seems to inhibit RNA and protein synthesis.

Makeyeva, V. F.↗

Biomedical technology transfer. Applications of NASA science and technology

Ongoing projects described address: (1) intracranial pressure monitoring; (2) versatile portable speech prosthesis; (3) cardiovascular magnetic measurements; (4) improved EMG biotelemetry for pediatrics; (5) ultrasonic kidney stone disintegration; (6) pediatric roentgen densitometry; (7) X-ray spatial frequency multiplexing; (8) mechanical impedance determination of bone strength; (9) visual-to-tactile mobility aid for the blind; (10) Purkinje image eyetracker and stabilized photocoalqulator; (11) neurological applications of NASA-SRI eyetracker; (12) ICU synthesized speech alarm; (13) NANOPHOR: microelectrophoresis instrument; (14) WRISTCOM: tactile communication system for the deaf-blind; (15) medical applications of NASA liquid-circulating garments; and (16) hip prosthesis with biotelemetry. Potential transfer projects include a person-portable versatile speech prosthesis, a critical care transport sytem, a clinical information system for cardiology, a programmable biofeedback orthosis for scoliosis a pediatric long-bone reconstruction, and spinal immobilization apparatus.

Harrison, D. C.↗

A specific radioimmunoassay for osteocalcin with advantageous species crossreactivity

The specificities of immunoassays to rat and bovine osteocalcin are examined. Extracts of noncalcified tissues and tissue fractions are unreactive to the antibody, with the exception of the kidney, in which the reactive component appears to be identical with osteocalcin by gel filtration and dose dilution analysis. The assays, developed against protein isolated from bone, are also demonstrated to be reactive to the native protein (bone in situ) and to osteocalcin in serum. The assays are sensitive to less than 50 pg osteocalcin. Intra- and interassay coefficients of variation are less than 6.8%. The bovine antibody crossreacts with human, horse, monkey, baboon, and cat osteocalcin, while the rat antibody crossreacts with dog and mouse.

Patterson-Allen, P.↗

Radiation from a double layer jet

The aerodynamic radiation caused by two acoustic point sources located symmetrically on the sides of a double layer jet which produces a velocity discontinuity was examined, with attention given to the effect on the sound by the stream. Basic equations were defined in terms of wave propagation in the fluid in motion and a Fourier transformation. It was found that the radiation due to a point source on one side of the jet is enhanced by the presence of sound transmitted from the other side. The effect is expressed as a function of the reflection coefficient, wherein the reflections take place at the vortex interfaces separating the fluid in motion from the fluid at rest. The intensity patterns were determined to be kidney-shaped, lung-shaped, and heart-shaped, and characterized by a deep valley in the directivity pattern. The significance of the findings for STOL aircraft ejector thrust augmentation is mentioned.

Dash, R.↗

Effects of simulated increased gravity on the rate of aging of rats - Implications for the rate of living theory of aging

It was found that the rate of aging of 17 month old rats which had been exposed to 3.14 times normal gravity in an animal centrifuge for 8 months was larger than that of the controls as determined by the apparently elevated lipofuscin content in heart and kidney, reduced numbers and increased size of mitochondria of heart tissue, and inferior liver mitochondria respiration. Steady-state food intake per day per kg body weight, which is presumably proportional to rate of living or specific basal metabolic expenditure, was found to be about 18 percent higher than in the controls after an initial 2 month adaptation period. Although half of the centrifuged animals lived only a little shorter than the controls (average about 343 vs. 364 days on the average, statistically nonsignificant), the remaining half (longest survivors) lived on the centrifuge an average of 520 days (range 483-572) compared to an average of 574 days (range 502-615) for the controls, computed from the onset of centrifugation, or 11 percent shorter. These findings indicate that a moderate increase of the level of basal metabolism of young adult rats adapted to hypergravity compared to controls in normal gravity is accompanied by a roughly similar increase in the rate of organ aging and reduction of survival, in agreement with Pearl's (1928) rate of living theory of aging, previously experimentally demonstrated only in poikilotherms.

Economos, A. C.↗

Effects of suspension on tissue levels of glucocorticoid receptors

Differential muscle responses can be simulated by hypokinetic/hypodynamic (H/H) suspension of rats with complete unloading of the hindlimb muscles. Since mechanism(s) underlying these atrophic effects were not clearly elucidated, experiments were initiated to investigate a possible role for glucocorticoids in the physiological and biochemical responses to H/H. The principal objective was to assess the potential for alterations in peripheral responsiveness to glucocorticoids in response to H/H. Studies have initially focused on the determination of tissue levels of glucocorticoid receptors as one index of hormonal sensitivity at the cellular level. Four hindlimb muscles (soleus, gastrocnemius, plantaris and EDL), previously demonstrated to exhibit differential responses to H/H, were investigated. Receptor levels in other glucocorticoid sensitive tissues (heart, liver, and kidney) were determined. Male rats (180-200g) were suspended for 7 or 14 days, sacrificed by cervical dislocation, and the tissues excised.

Steffen, J. M.↗

Suprathermal ions upstream from interplanetary shocks

Low energy (10 eV-30 keV) observations of suprathermal ions ahead of outward propagating interplanetary shock waves (ISQ) are reported. The data were taken with the fast plasma experiment on ISEE 1 and 2 during 17 events. Structure was more evident in the suprathermal ion distribution in the earth bow shock region than in the upstream region. Isotropic distributions were only observed ahead of ISW, although field alignment, kidney-bean distributions, ion shells in velocity space and bunches of gyrating ions were not. The data suggest that the solar wind ions are accelerated to suprathermal energies in the vicinity of the shocks, which feature low and subcritical Mach numbers at 1 AU.

Gosling, J. T.↗

Rapid diagnostic methods for influenza virus in clinical specimens - A comparative study

A comparison of five rapid viral diagnostic techniques for identifying influenza virus in nasopharyngeal aspirates has been made on patients with influenza-like illnesses. Initial results with immune electron microscopy were positive in only one of 11 specimens from which virus was isolated and further work abandoned. Four other rapid tests were carried out on 39 specimens from which influenza virus had been isolated in tissue culture in 28. Of these 28 specimens yielding virus, 24 (85.7 percent) were positive by an indirect fluorescent antibody test (IFAT) on nasopharyngeal cells, 18 (64.3 percent) by enzyme-linked immunosorbent assay (ELISA), 19 (67.8 percent) by enzyme-linked fluorescent assay (ELFA), and 26 (92.8 percent) by a rapid tissue culture amplification method (TCA) in a continuous Rhesus monkey kidney line (LLC-MK2) with identification of virus by fluorescent antibody. In terms of sensitivity, simplicity, and rapidity, a combination of the IFAT and TCA methods seems to be very useful.

Evans, A. S.↗

Development of a Prosthesis for Urinary Control

Report describes development and marketing of prosthetic sphincter for urinary control. With prosthetic device, patients void bladder every 3 to 4 hours. Periodic voiding keeps bladder muscles exercised and healthy and avoids bladder infections and kidney damage.

Tenney, J. B.↗

Bioprocessing in space

Attachment to a substrate and survival of human embryonic kidney cells (HEK) was tested in an incubator installed in the flight-deck of the space shuttle Challenger. The HEK cells produce the enzyme urokinase and are candidates for electrophoretic separation. Attachment of the cells to a substrate is mandatory for survival. Analysis of the samples shows that cells adhere, spread and survive in 0 g conditions as well as the ground controls at 1 g.

Tschopp, A.↗

Neural Mechanism by which Gravitational Stimuli and Stress Affect the Secretion of Renin and Other Hormones

The serotonin-releasing drug p-chloroamphetamine (PCA), as well as L-propranolol and chloriasondamine were used in a study which established that the pathway from the hypothalamus to the kidneys is sympathetic. Which hypothalamic nuclei mediate the response to PCA is being investigated experiments are being conducted to determine a readily reproducible psychological stimulus to renin secretion that can be used in rats. The effects of equithesin, urethane, and inactin on plasma renin activity were examined in preparation for tilting experiments. The relation of vasopressin-secreting neurons in the brain sem to PCA response was explored in Brattleboro rats that are congenitally unable to produce vasopressin in their hypothalami.

Ganong, W. F.↗