The preventive role of ultraviolet radiation during exposure to ionizing radiation
The effect of suberythematous doses of ultraviolet and ionizing radiation on sulfhydryl groups, cholesterol and hemoglobin of the blood is studied.
Yatsula, G. S.↗
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Morphological and functional manifestations of rat adrenal-cortex response to sodium bromide administration under hypodynamic stress
Functional and morphological manifestations of adrenal cortex response to hypodynamia (2-hr immobilization on an operating table) under the influence of bromine preparations were studied. The sodium bromide was administered intraperitoneally in 100, 250, and 500 mg/kg doses once and repeatedly during ten days. The adrenal gland was evaluated functionally by ascorbic acid and cholesterol content and morphologically by coloring it with hematoxylin-eosin and Sudans for lipid revealing at freezing. Results are displayed in two tables and microphotographs. They are summarized as follows: the bromine weakens the functional state of the adrenal cortex in intact rats, causing changes similar to those under stress. During immobilization combined with preliminary bromine administration, a less pronounced stress reaction is noticeable.
Kirichek, L. T.↗
Effect of graded physical load on the state of the liver from morphometric data and biochemical blood indices of rats against a background of hypokinesia
Tests were conducted on 100 sexually immature inbred August and Wistar male rats in order to determine the effects hypokinesia, physical load and phenamine on the liver. Weight and linear dimension fell in hypokinesia; total serum protein lowered and aldolase and cholesterol and beta-lipoprotein levels rose. Blood sugar content rose and liver glycogen fell. Interlinear differences of these indices are found. Rehabilitated physical loading against hypokinesia background diminished and at times completely prevented its negative effect. Extent of correction depended on animal species. Evidence of genotypical conditionality of organism adaptation to physical load in hypokinesia was found.
Nikityuk, B. A.↗
Experimental coronary sclerosis induced by immobilization of rabbits: A new model of arteriosclerosis
A new method for producing arteriosclerosis with coronary insufficiency in rabbits by means of immobilization is described and discussed. The experimentally induced atherosclerosis develops due to hypodynamics imposed by the reduced muscular activity without overloading with exogenous cholesterol. The atherosclerosis and coronary insufficiency are associated. With variations in the duration and extent of immobilization, coronary insufficiency alone or with atherosclerosis can be produced.
Tyavokin, V. V.↗
Fitness variables and the lipid profile in United States astronauts
The study examines the relationship between several measures of fitness and the lipid profile in United States astronauts. Data were collected on 89 astronauts, previously selected (PSA) and newly selected (NSA), during their annual physical examinations. Several similarities were seen in the two groups. The PSA (mean age of 46.1) had a lower maximum oxygen capacity (41.7 ml kg/min vs. 47.5 ml kg/min); when adjusted for age, it was no different from the NSA (mean age 33.5). The PSA had similar body composition with 15.7% - lower than expected for age. The lipid profiles of the two groups were basically the same with the differences being a function of age. Compared to a normative population, the astronauts had similar cholesterols, lower triglycerides, and higher HDLs. The astronaut profiles were generally more favorable than the age-matched controls, which is felt to be a result of the self-supervised conditioning program and annual preventive medicine consultation and education.
Berry, M. A.↗
Coprostanol as a potential tracer of particulate sewage effluent to shelf waters adjacent to the Chesapeake Bay
Samples were collected in the Chesapeake Bay entrance and contiguous shelf waters and were subsequently analyzed for particulate coprostanol and cholesterol concentrations. Surface coprostanol concentrations were fairly uniform, with a slight increase with depth. This increase with depth may be due to sewage-associated particulates settling as they leave the Bay, or the resuspension of contaminated sediment. Preliminary findings indicate sewage-associated materials are being transported from the Chesapeake Bay to shelf waters, where they may have a detrimental affect on living marine resources.
Brown, R. C.↗
Velocity and attenuation of sound in arterial tissues
The velocity of sound in excised human and canine arterial tissues is measured in order to serve as a basis for the development and application of ultrasonic techniques for the diagnosis of atherosclerotic lesions. Measurements of sound velocity at different regions of 11 human and six canine aortas were made by a time delay spectrometer technique at frequencies from 2 to 10 MHz, and compared with ultrasonic attenuation parameters and the results of biochemical assays. Sound velocity is found to increase with increasing attenuation at all frequencies, and with increasing collagen content. A strong dependence of sound velocity on cholesterol content or low calcium contents is not observed, although velocities of up to 2000 m/sec are observed in highly organized calcified lesions. A decrease in velocity with decreasing temperature is also noted. It is thus concluded that it is principally the differences in tissue collagen levels that contribute to image formation according to sound velocity.
Rooney, J. A.↗
A critical synopsis: Continuous growth of proximal tubular kidney epithelial cells in hormone-supplemented serum-free medium
The kidney forms urine and reabsorbs electrolytes and water. Kidney cell lines and hormone supplemented serum free medium were used for growth. The hormones were insulin, transferrin, vasopressin, cholesterol, prostaglandins, hydrocortisone, and triidothyronine. Epithelial cell lines are polar and form hemicysts. The Madin-Darby canine kidney(MDCK) cell line used is distal tubulelike. LLC-PK sub 1 cells are derived from pig kidneys and have the properties of different kidney segments. The LLC-PK sub 1 cells with proximal tubule properties were maintained in hormone-supplemented serum free medium. Seven factors (the aforementioned homrones and selenium) were needed for growth. Hormone-defined medium supported LLC-PK sub 1 cell growth, allowed transport (as seen by hemicyst formation), and influenced cell morphology. Vasopressin (used for growth and morphology) could be partially replaced by isobutylmethylxanthine or dibutyryl cAMP. The defined medium was used to isolate rabbit proximal tubule kidney epithelial cells free of fibroblasts.
Chuman, L. M.↗
Liposomes with polyribonucleotides as model of precellular systems
Three types of liposomes were prepared under anoxic conditions: from dipalmitoyl phosphatidyl choline (DPPC), from egg yolk phosphatidyl choline (PC), and from PC with cholesterol (PC:Chol). These were used for encapsulation of poly(U) and poly(C). It was found that 36 to 70 percent of the available liposome lipids and 2 to 5 percent of the polyribonucleotides could be entrapped. An enhanced encapsulation of poly(U) and poly(C) by all three types of liposomes was observed in the presence of 0.001 to 0.01 M Zn(2+), with the effect being greatest with DPPC. The presence of 1.0 M urea inhibited the formation of PC liposomes.
Baeza, Isabel↗
Effect of breakfast on selected serum and cardiovascular variables
In view of the objections of many subjects to overnight fasting prior to their blood being drawn for analyses, the effect of eating breakfast on the results of subsequent blood analyses of selected blood constituents and on cardiovascular variables was investigated in 47 men and 34 women who were subjected to blood analyses on two occasions, one week apart: once fasting and once after breakfast. Results suggest that subjects need not fast overnight before blood is being drawn for determinations of the HDL-C levels, hemoglobin, hematocrit, total cholesterol, or phosphorus. However, based on other studies, it is suggested breakfast should not have a high content of fat.
Frey, Mary A. B.↗
Analyses of plasma for metabolic and hormonal changes in rats flown aboard Cosmos 2044
Plasmas samples from rats flown aboard Cosmos 2044 were analyzed for the levels of key metabolites, electrolytes, enzymes, and hormones. The major differences between the flight group and the synchronous control were elevations in glucose, cholesterol, phosphate, creatinine, blood urea nitrogen, lactate dehydrogenase, and aspartate aminotransferase and decreased levels of thyroxine. Most of these differences were not mimicked by tail suspension of ground-based rats; however, both flight and suspended rats exhibited inhibited testosterone secretion. Corticosterone, immunoreactive growth hormone, and prolactin showed inconsistent differences from the various control groups, suggesting that the levels of these hormones were not due to actual or simulated microgravity.
Merrill, Alfred H., Jr.↗
Clinical aspects of telemedicine
Communication among physicians is an essential in order to combine our experiences for the elucidation and application of new knowledge and for the accurate and uniform application of established medical practice. This communication requires an adequate understanding of the culture of the patient and the social context of disease and indeed the culture of the physician. Malnutrition in Bangladesh means caloric insufficiency, and a program to lower cholesterol would be impertinent, while a program to enhance the nutrition of patients in Texas by an international effort to import more grain would be ludicrous. In the same vein a public health effort to combat alcoholic cirrhosis in Mecca would be as silly as a program to increase fiber in the diet of the Bantu. Clinical communication must acknowledge the culture of the issue at hand and the differences in the experiential base of the physicians. Not only do geography and culture affect the potential differences in the experiential bases, but the world utilizes very different traditions of education and science in training physicians. We are influenced by the diseases we treat, and learn to look for the expected at least as much as we are attentive to the unexpected. A physician in Siberia would be much more likely to recognize frostbite than one from Buenos Aires, and the Argentine doctor would much more likely consider Chaga's Disease to explain abdominal pain than a colleague in Zurich. Beyond these obvious issues in communication among physicians we must deal with the many languages and idioms used in the world. An overview of using Telemedicine SpaceBridge after the earthquake in the Republic of Armenia in 1988 is presented.
Merrell, Ronald C.↗
Vascular Responsiveness in Adrenalectomized Rats with Corticosterone Replacement
To determine under resting, unstressed conditions the circulating glucocorticoid concentrations that best maintain sensitivity of the vascular smooth muscle and baroreceptor responses to vasoactive agents, rats with vascular cannulas were sham-adrenalectomized (sham) or adrenalectomized (ADRX) and provided with four levels of corticosterone replacement (-100 mg fused pellets of corticosterone: cholesterol 0, 20, 40, and 80% implanted subcutaneously at the time of adrenal surgery). Changes in vascular and baroreflex responses were determined after intravenous injection of varying doses of phenylephrine and nitroglycerin with measurement of arterial blood pressure and heart rate in the conscious, chronically cannulated rats. Vascular sensitivity was decreased, and resting arterial blood pressure tended to be decreased in the adrenalectomized rats; both were restored to normal with levels of corticosterone (40%), which also maintained body weight gain, thymus weight, and plasma corticosteroid binding globulin concentrations at normal values. The baroreflex curve generated from the sham group was different from the curves generated from the ADRX+O, 20, and 40% groups, but not different from that of the ADRX+80% group, suggesting that the baroreflex is maintained by higher levels of corticosterone than are necessary for the maintenance of the other variables. These data demonstrate that physiological levels of corticosterone (40% pellet) restore vascular responsiveness, body weight, thymus weight, and transcortin levels to normal in ADRX rats, whereas higher levels (80% pellet) are necessary for restoration of the baroreflex.
Darlington, Daniel N.↗
Monitoring Astronaut Health at the Nanoscale Cellular Level Through the Eye
A user friendly goggles-like head-mounted device equipped with a suite of instruments for several non-invasive and quantitative medical evaluation of the eye, skin, and brain is desired for monitoring the health of astronauts during space travel and exploration of neighboring and distant planets. Real-time non-invasive evaluation of the different structures within the above organs can provide indices of the health of not just these organs, but the entire body. The techniques such as dynamic light scattering (for the early detection of uveitis, cholesterol levels, cataract, changes in the vitreous and possibly Alzheimer's disease), corneal autofluorescence (to assess extracellular matrix biology e.g., in diabetes), optical activity measurements (of anterior ocular fluid to evaluate blood-glucose levels), laser Doppler velocimetry (to assess retinal, optic nerve, and choroidal blood flow), reflectometry/oximetry (for assessing ocular and central nervous system oxygen metabolism), optical coherence tomography (to determine retinal tissue microstructure) and possibly scanning laser technology (for intraocular tissue imaging and scanning) will he integrated into this compact device. Skin sensors will also be mounted on the portion of the device in contact with the periocular region. This will enable monitoring of body temperature, EEG, and electrolyte status. This device will monitor astronaut health during long-duration space travel by detecting aberrations from pre-established "nonns", enabling prompt diagnosis and possibly the initiation of early preventative/curative therapy. The non-invasive nature of the device technologies permits frequent repetition of tests, enabling real-time complete crew health monitoring. This device may ultimately be useful in tele-medicine to bring modern healthcare to under-served areas on Earth as well as in so-called "advanced" care settings (e.g. diabetes in the USA).
Ansari, Rafat R.↗
Ethnic Differences in Physical Fitness, Blood Pressure and Blood Chemistry in Women (AGES 20-63)
This study examined the role of ethnicity on the aerobic fitness, blood pressure, and selected blood chemistry values of women. One hundred twenty-four females (mean age 41.37 +/- 9.0) were medically Examined at the NASA/Johnson Space Center occupational health clinic. Ethnic groups consisted of 23 Black (B), 18 Hispanic (H) and 83 Non-minority (NM). Each woman had a maximum Bruce treadmill stress test (RER greater than or = 1.1) and a negative ECG. Indirect calorimetry, skinfolds, self-report physical activity (NASA activity scale), seated blood pressure, and blood chemistry panel determined VO2max, percent fat, level of physical activity, blood pressure and blood chemistry values. ANOVA revealed that the groups did not differ (p greater than 0.05) in age, VO2 max, weight, percent fat, level of physical activity, total cholesterol, or HDL-C. However, significant differences (p greater than 0.05) were noted in BMI, diastolic blood pressure, and blood chemistries. BMI was 3.17 higher in H than in NM; resting diastolic pressures were 5.69 and 8.05 mmHg. lower in NM and H than in B; triglycerides were 48.07 and 37.21 mg/dl higher in H than in B and NM; hemoglobin was .814 gm/dl higher in NM than B; fasting blood sugar was 15.41 mg/dl higher in H than NM; The results of this study showed that ethnic groups differed in blood pressure and blood chemistry values but not aerobic fitness or physical activity. There was an ethnic difference in BMI but not percent fat.
Ayers, G. W.↗
Effects of Cage Type and NASA Rodent Food Bar in Male Sprague-Dawley Rats
Early prototype caging for the rodent Advanced Animal Habitat (P-AAH) for the International Space Station (ISS) is currently being tested. In this five week study, effects of the wire-bottom P-AAH cages and specialized NASA rodent food bars (FB) were compared to standard vivarium cages (VIV) with corn-cob, litter-filled bottoms, and standard Purina rat chow (CH). Ninety-six male Sprague-Dawley rats were divided into four treatment groups (24 rats/treatment): Group 1) VIV+CH, Group 2) P-AAH+CH, Group 3) VIV+FB, and Group 4) P-AAH+FB. Each VIV and P-AAH cage housed three and six rats, respectively. After five weeks of treatment rats were weighed, euthanized, and blood samples were collected. Weights of liver (LIV), kidney (KID), brain (BRN), epididymal fat (EPI), and perirenal fat (PERI) were also measured. Statistical analysis to compare differences between groups was performed by standard analysis of variance procedures (ANOVA) with a significance level of pLO.05. Results indicated P-AAH housed rats had significantly lower body weights (BW), LIV weights, and LIV/BW than VIV housed rats. FB fed rats had significantly lower blood urea nitrogen (BUN) levels and LIV/BW than CH fed rats. In addition, FB fed rats had significantly higher cholesterol (CHOL) levels, EPI/BW, PERI/BW, and total fat (EPI+PERI)/BW than CH fed rats. The P-AAH+FB group had significantly lower EPI, BRN, and total fat than VIV+FB rats. VIV+FB rats had significantly higher BRN, EPI, PERI, and total fat than VIV+CH rats. Triglycerides (TG), KID, KID/BW, and BRN/BW were not significantly different among treatment groups. These findings provide valuable information regarding cage design and food bar suitability for long-term use on the ISS.
Lau, Angela↗
Identification of Methanotrophic Biomarker Lipids in the Symbiont-Containing Gills of Seep Mussels
Mussels collected from hydrocarbon seeps in the Gulf of Mexico grow with methane as sole carbon and energy source due to a symbiotic association with methane-oxidizing bacteria. Transmission electron micrographs of mussel gills show cells with stacked intracytoplasmic membranes similar to type I methanotrophic bacteria. Methanotrophs are known to synthesize several types of cyclic triterpenes, hopanoids and methyl sterols, as well as unique monounsaturated fatty acid, double bond positional isomers that serve as biomarkers for this group. Lipid analysis of dissected mussels demonstrated the presence of these biomarkers predominantly in the gill tissue with much smaller amounts in mantle and remaining body tissues. Gill tissue contained 1150 micrograms/g dry wt. of hopanepolyol derivatives and diplopterol while the mantle tissue contained only 17 micrograms/g. The C16 monounsaturated fatty acids (16:1) characteristic of type I methanotrophic membranes dominated the gill tissue making up 53% of the total while only 5% 16:1 was present in the mantle tissue. The methyl sterol distribution was more dispersed. The predominant sterol in all tissues was cholesterol with lesser amounts of other desmethyl and 4-methyl sterols. The gill and mantle tissues contained 3461 micrograms (17% methyl) and 2750 micrograms (5% methyl) sterol per gm dry wt., respectively. Methyl sterol accounted for 44% of the sterol esters isolated from the gill, suggesting active demethylation of the methanotrophic sterols in this tissue. The use of lipid biomarkers could provide an effective means for identifying host-symbiont relationships.
Jahnke, L. L.↗
NASA Rodent Foodbar: Long Term Effects in Swiss Webster Mice
Swiss Webster male and female mice (150 of each) were fed NASA Rodent Foodbar for more than 110 days to test the diet's nutritional adequacy for use in future long-term studies aboard the International Space Station. Mice were grouped three to a cage (one cage = one sample) and cages were assigned to either Foodbar or Purina Chow #5001 (control) diet groups. Body weights, food intake, and water intake were obtained throughout the study. There were no significant differences in body weights between male Foodbar fed and Chow fed males (p=0.58), and at 15 weeks into the female mouse study there appear to be no significant body weight differences. Both male and female Foodbar fed groups consumed more food and less water than their Chow controls, both factors thought to be attributable to the high moisture content of the Foodbars (26% versus 10% for Chow). All differences in gross food and water consumption had p-values of less than 0.01. When food and water intake were adjusted for the moisture content in the food, both male and female Foodbar fed animals consumed less food, but still had a lower water intake rate than their controls. (p is less than 0.01). Preliminary analysis on blood samples from male and female halfway point dissections suggests differences in glucose and fat metabolism. In both male and female Foodbar fed animals, blood glucose values were significantly lower (p is less than 0.01) but there were no significant differences in cholesterol levels (p=0.51). In Foodbar fed females, triglycerides were significantly higher (p is less than 0.01). These data suggest that Foodbars allow for normal growth in Swiss Webster mice, but affect some blood chemistry parameters.
Santiago, D. L.↗