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Results 651 - 700 of 811
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Kawashima A - - 1989
To verify the presence of the constitutional abnormality implicated in the pathogenesis of high-altitude pulmonary edema (HAPE), we evaluated the hemodynamic responses to hypoxia, hypobaria, and exercise in HAPE-susceptible subjects (HAPE-S). HAPE-S were five males with a history of HAPE. Five healthy volunteers who had repeated experiences of mountain climbing ...
Knutson C - - 1989
An increase in utilization of prenatal diagnosis was observed from 1985 to 1986 in South Carolina. The overall rate of 39.9% for 1986 is comparable with other areas of the U.S. Utilization was correlated with geographic residence, race, and referral source. While there was considerable variation in prenatal diagnostic test ...
Guezennec C Y - - 1989
Several studies have shown that hemorrheological parameters are modified by physical exercise and exposure to altitude hypoxia. These changes result in a decrease in red cell deformability (RCD). Similarly, it has been shown that a daily dietary fish oil supplement increases RCD. The purpose of this study was to evaluate ...
Bouissou P - - 1989
The renin-aldosterone system may be depressed in subjects exercising at high altitude, thereby preventing excessive angiotensin I (ANG I) and aldosterone levels, which could favor the onset of acute mountain sickness. The role of beta-adrenoceptors in hormonal responses to hypoxia was investigated in 12 subjects treated with a nonselective beta-blocker, ...
Cymerman A - - 1989
Chronic exposure to high altitude reduces maximal O2 uptake (VO2max). At extreme altitudes approaching the summit of Mt. Everest [inspiratory PO2(PIO2) = 43 Torr], mean VO2max have been determined to be 15.3 ml.kg-1.min-1 in two subjects who breathed 14% O2 at 6,300 m on Mt. Everest (West et al., J. ...
Shinomura Y - - 1989
Sizes of spleen and liver were studied by measuring spleen index calculated by multiplying the maximal length by the maximal width of the spleen and liver length at right mid-clavicular line below the costal margin using ultrasonography in 26 Papua New Guineans and in 25 Japaneses living in Papua New ...
Bermúdez De Castro J M - - 1989
The incidence of the different degrees of expression of Carabelli's trait in the deciduous and permanent dentitions was obtained on 651 skulls of three human prehistoric aboriginal samples from Gran Canaria (n = 329), Tenerife (n = 297) and La Gomera (n = 25) Islands. In the Gran Canaria sample, ...
Lints F A - - 1989
In Drosophila melanogaster daily fecundity has been recorded throughout life of flies kept at various gravity levels (1-5 g). Hypergravity (HG) did not decrease total fecundity but modified its expression during life. The 1 g group could be opposed to the various HG groups, i.e. a clear regression of the ...
Brinchmann-Hansen O - - 1989
Computerised microdensitometry was used to study diameter changes in 93 arterial and 91 venous vessel sites in the retinas of four mountain climbers before and after spending seven weeks in the Himalaya mountains. The vascular response to short-term strenuous exercise was measured at sea level, to acute hypoxia of simulated ...
Dixon G A - - 1988
The purpose of this study was to measure female susceptibility to decompression sickness (DCS) during simulated extravehicular activity (EVA) at a candidate (7.8 psia) suit pressure. Thirty female volunteer subjects, in groups of three, were exposed to three consecutive daily EVA simulations at 7.8 psia (5,031 m altitude equivalent) continuously ...
Horvath S M - - 1988
In order to assess the combined effects of altitude and acute carbon monoxide exposure, 11 male and 12 female subjects, nonsmokers in good health, were given incremental (two minutes at each workload) maximal aerobic capacity tests at four levels of ambient carbon monoxide (0, 50, 100, and 150 parts per ...
Horvath S M - - 1988
To assess the nature of the combined effect of the hypoxias of altitude (ALT) and CO exposure, 11 men and 12 women nonsmokers served as subjects in a double-blind experiment. The exposure conditions were four ambient CO levels (0, 50, 100, and 150 ppm) at each of four ALT (55, ...
Kumar K V - - 1988
The risk of decompression sickness (DCS) is greatly increased with exercise at altitude. Bends is the commonest symptom in altitude DCS. Though the adverse effect of exercise at altitude is well known, the role of exercise during decompression is not clear. In this paper, a case of bends occurring with ...
Jackson C G - - 1988
The effect of altitude on human performance is complex. Numerous variables are known to change from sea-level measures. Maximum aerobic power is depressed as ascent occurs and this impairs the ability to work maximally. While changes in haematological variables would theoretically counterbalance the loss in aerobic power, they have not ...
Perna J - - 1988
Outward Bound programs are carried out throughout the world, and many of these courses occur at altitudes above 3000 m (10,000 ft). As more knowledge is accumulated about health problems at high altitudes, exercise has been implicated as a factor contributing to acute mountain sickness in susceptible individuals. Thus, exercise ...
Kraemer W J - - 1988
The purpose of this study was to examine the resting and exercise response patterns of plasma Peptide F immunoreactivity (ir) to altitude exposure (4300 m) and caffeine ingestion (4 mg.kg b.w.-1). Nine healthy male subjects performed exercise tests to exhaustion (80-85% VO2max) at sea level (50 m), during an acute ...
Olson R M - - 1988
Several investigators have reported that intravascular bubbles can be detected in decompressed subjects before they develop bends. The altitude exposures were generally of short duration with a limited number of subjects. This important preliminary finding needed to be verified in a larger sampling of long duration altitude exposures. In this ...
Shukitt B L - - 1988
Personal anecdotes suggest that ascent to high altitude can cause mood changes such as depression, apathy, and drowsiness. Observed behaviors at high altitude indicate that people can become more euphoric, irritable, or argumentative. Since there are few systematic and quantitative studies assessing the effects of altitude on mood, this study ...
Weisman I M - - 1988
In previous work (Weisman IM, Zeballos RJ, Johnson BD: Cardiopulmonary and gas exchange responses to acute strenuous exercise at 1,270 meters in sickle cell trait. Am J Med 1988; 84: 377-383), no significant differences in cardiopulmonary and gas exchange responses to acute, strenuous exercise were observed between volunteers with sickle ...
Beard J L - - 1988
Thirty-seven young adult male highland residents at 3,600-4,100 m in La Paz, Bolivia, performed short-duration cycle ergometry at 60, 80, and 100% of maximal voluntary O2 consumption (VO2max). Three groups of subjects representing the high-altitude population mean hemoglobin (Hb), the 10th percentile Hb, and below the 1st percentile were examined ...
De Paoli Vitali E - - 1988
Serum erythropoietin (Epo) activity, hemoglobin (Hb), and hematocrit (Ht) were determined in 21 cross-country skiers during the training season. The Epo levels were not significantly reduced in the skiers relative to the normal population (P less than 0.01 and P less than 0.001, respectively). In 11 athletes Epo, Ht, urinary ...
Maresh C M - - 1988
Submaximal and maximal exercise responses were examined in persons (age, 19-30 years) residing at a moderate altitude for different periods of time. Long-term residents (LTR; 44 males, 11 females) had lived continuously between 1,830 and 2,200 m for 2 years or longer before testing. Short-term residents (STR; 22 males, 30 ...
Richalet J P - - 1988
Cardiac chronotropic response to adrenergic activity at rest and exercise has been studied in 8 sea-level natives on the first two days of exposure to high altitude hypoxia (3823 m, 473 mmHg). Maximal O2 uptake (VO2max) was determined at low altitude (day 0:D0) and high altitude (day 2:D2). Submaximal exercise ...
Fellmann N - - 1988
In a previous study we showed that there were no differences in anaerobic metabolism between groups of 11-yr-old children living at high (3,700 m) and low (330 m) altitudes. The aim of this study is to investigate changes in this metabolism during pubertal development. We compare blood lactate concentration ([L]) ...
Weisman I M - - 1988
The impact of strenuous exercise and environmental hypoxia on sickle cell trait (SCT) remains controversial. To determine if these factors induce cardiopulmonary and gas exchange abnormalities in SCT, healthy, young black male volunteers, 25 with SCT (HbAS) and 16 control subjects (HbAA), were evaluated during incremental and steady-state exercise tests ...
Lee E J - - 1988
A study was performed to show whether debrisoquine phenotyping could be performed as an overnight procedure. Phenotyping of 33 normal volunteers was carried out during the day and night. A good correlation was observed between the day- and night-time metabolic ratios, although wide variation was observed in 3 subjects.
Rumble R H - - 1988
Previous reports have produced conflicting results as to whether changes in posture affected the pharmacokinetics of the penicillins. We have studied the pharmacokinetics of intramuscularly administered benzylpenicillin in normal subjects during bedrest and ambulation and compared it with data obtained following intravenous administration of the same dose to the same ...
Westermeyer J - - 1988
Folk healing was studied in two ethnic groups of Laos during the period 1965-75. Hmong, mostly illiterate and animistic, lived in highly autonomous villages within an atomistic society, occupying remote and sparsely populated mountains. Lao, mostly literate and Buddhist, lived in lowland towns and villages within a hierarchical and integrated ...
Terrados N - - 1988
Differences between the effects of training at sea level and at simulated altitude on performance and muscle structural and biochemical properties were investigated in 8 competitive cyclists who trained for 3-4 weeks, 4-5 sessions/week, each session consisting of cycling for 60-90 min continuously and 45-60 min intermittently. Four subjects, the ...
Saito T - - 1988
A recent decline in consanguineous marriages in Japan should have resulted in a decrease in the incidence of autosomal recessive disorders. Theoretical estimates were made of the chronological decrease in the incidence using a formula for Hardy-Weinberg expectation in a partially inbred population and applying appropriate consanguinity rates, taken from ...
Lett B T - - 1988
Rats learn to prefer a place that has been paired with the rewarding effect of amphetamine. Since amphetamine is also known to produce an aversive effect, called here sickness, pairings of a place with amphetamine should produce a place-sickness association as well as the place-reward association that underlies the conditioned ...
Wagner P D - - 1987
Eight normal subjects were decompressed to barometric pressure (PB) = 240 Torr over 40 days. The ventilation-perfusion (VA/Q) distribution was estimated at rest and during exercise [up to 80-90% maximal O2 uptake (VO2 max)] by the multiple inert gas elimination technique at sea level and PB = 428, 347, 282, ...
Moore L G - - 1987
Previously, we found resting metabolic rate increased at high altitude but the mechanism and consequences of this increase were unclear. We sought to test the role of beta-sympathetic activation for increasing metabolic rate and the contribution of an increase in metabolic rate to raising total ventilation at altitude. Following baseline ...
Packard A B - - 1987
A new osmium-191/iridium-191m (191Os/191mIr) radionuclide generator has been developed that offers high 191mIr yield (greater than 20%/ml) and low 191Os breakthrough (less than 5 X 10(-4)%/ml) when eluted with a solution of 0.001 M oxalic acid and 0.9% (normal) saline. This is the first 191Os/191mIr generator that combines the advantages ...
Krutz R W RW - - 1987
This study assessed the value of controlled exercise in a bends susceptibility test. Healthy male subjects were exposed to a pressure altitude of 9,100 m (30,000 ft; 4.3 psia) for a period not exceeding 8 h on two separate days at least 1 week apart. During one exposure, subjects performed ...
Waligora J M - - 1987
The purpose of this study was to determine the effect of extended O2 prebreathing on symptom and bubble incidence during decompressions simulating extravehicular activity. The 38 subjects breathed O2 for a 6-h period prior to decompression to 4.3 psi. The subjects performed upper body exercise for 6 h. Subjects were ...
Andrew M - - 1987
Thromboembolic phenomena may occur as humans ascend to high altitude. To investigate the role of the coagulation cascade and its inhibitors in these disorders, venous blood was obtained from eight subjects who participated in the Operation Everest II project. Samples were obtained before and 5 min after completion of a ...
Martin N A - - 1987
The Scott Emergency Escape Breathing Device (EEBD) was evaluated for use in Canadian Forces (CF) transport/passenger aircraft in providing smoke protection during emergencies and in preventing hypoxia during cabin decompression at high altitude. Five human subjects wearing the EEBD were subjected to decompression from 2,438 m (8,000 ft) to 9,753 ...
Young P M - - 1987
This study examined the effects of acclimatization to 4,300 m altitude on changes in plasma ammonia concentrations with 30 min of submaximal [75% maximal O2 uptake (VO2max)] cycle exercise. Human test subjects were divided into a sedentary (n = 6) and active group (n = 5). Maximal uptake (VO2max) was ...
Caldwell J E - - 1987
Drugs that induce an increased urine flow are used both legitimately (treatment of hypertension and oedema) and otherwise (rapid weight loss) in sports and exercise. There are 5 major categories of diuretic drugs based on their mechanisms and loci of action. Common to all classes is hypohydration, which has been ...
Hart L E - - 1987
Physical activity, whether at a competitive or a recreational level, is frequently affected by environmental conditions. With changes in the natural environment, the exercising individual invokes a series of complex physiologic responses that are directed at maintaining homeostasis. This article will focus on the nature of these responses, with special ...
Bradwell A R - - 1987
Twenty-one subjects formed a trekking expedition to study the effects of acetazolamide on exercise performance and acclimatization at high altitude. Subjects were randomized to acetazolamide or placebo on a double blind basis. During ascent to and stay for 6 nights at 4846 m studies were carried out on blood gases, ...
Burse R L - - 1987
The purpose of this investigation was to determine if the hyperventilatory response to fatiguing isometric exercise at sea level could predict resting ventilation and acute mountain sickness (AMS) at 4300 m altitude. Exercise consisted of four successive endurance handgrips held to complete fatigue at 40% of maximum isometric handgrip strength ...
Mills J - - 1987
Recurrent orofacial herpes infection may be triggered by high altitude skiing, presumably because of solar ultraviolet radiation exposure. Six (12%) of a group of 51 subjects with a history of skiing-triggered herpes observed during 1 week of high altitude skiing experienced reactivations of orofacial herpes a median of 3 1/2 ...
Mader T H - - 1987
Transconjunctival oxygen tension (PcjO2) was studied using a hypobaric chamber and during mountaineering excursions. Measurements obtained during acute chamber exposures (15-20 min) at sea level, 1829 m (6,000 ft), 3048 m (10,000 ft), 4267 m (14,000 ft) and return to sea level were (means +/- SEM): 60.1 +/- 2.7, 49.1 ...
West J B - - 1986
Maximal exercise at extreme altitude results in profound arterial hypoxemia and, presumably, extreme tissue hypoxia. The best evidence available indicates that the resting arterial PO2 on the summit of Mount Everest is about 28 torr and that it falls even further during exercise. Nevertheless, some 10 climbers have now reached ...
Choi V L - - 1986
Occurrence sampling was used in the main production area of a university residence hall foodservice to measure and analyze work functions involved in entrée production and to determine time requirements for entrée categories. Sixteen entrées were investigated: seven single-item, six combination, and three roast. Data collection took place in a ...
Moore L G - - 1986
Decreased maximal O2 uptake (VO2max) and stimulation of the sympathetic nervous system have been previously shown to occur at high altitude. We hypothesized that tachycardia mediated by beta-adrenergic stimulation acted to defend VO2max at high altitude. Propranolol treatment beginning before high-altitude (4,300 m) ascent reduced heart rate during maximal and ...
Askew,E. W.
The Meal, Ready-To-Eat (MRE) ration was fed ad libitum to a group of 15 soldiers for a period of 12 days. Ten of the 12 days were spent under field conditions at moderate (7,200 feet) altitude. Seven of the 10 days at altitude were exercise days wherein the soldiers ran ...
Wagner P D - - 1986
In a previous study of normal subjects exercising at sea level and simulated altitude, ventilation-perfusion (VA/Q) inequality and alveolar-end-capillary O2 diffusion limitation (DIFF) were found to increase on exercise at altitude, but at sea level the changes did not reach statistical significance. This paper reports additional measurements of VA/Q inequality ...
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