Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0392674 (exhaustion)
 13,658 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An experiment to validate predictions concerning submersible survivability was performed in December, 1975, by members of the Canadian Forces in the CF Submersible Lockout Vehicle SDL-1 in Halifax Harbour in water of 4 degrees C temperature at a depth of 40 ft. Data was collected relevant to the life support equipment to determine if it would operate for a simulated 6-h mission followed by a 24-h immobility period, at the end of which rescue was presumed to have occurred. Physiological data was collected from the submersible occupants in order to assess the degree of thermal stress experienced in this exercise. The experiment was terminated after a duration of approximately 25 h at 1 atm internal pressure due to exhaustion of two of the three on-board power supplies, causing the CO2 scrubbers to be inoperative and the CO2 content in the breathing gas to increase to toxic levels. Only two of the three submersible occupants experienced cold stress, one in the forward sphere and one in the aft sphere. At the end of 24 h, the core temperatures of both individuals had decreased by 0.5 degrees C and, during this time, skin temperatures, particularly of the extremities, had steadily and slowly decreased. Neither individual was hypothermic, but it was considered likely that after a 3-d exposure, at least two of the crew members would have had core temperatures of 35 degrees C or lower, assuming that CO2 poisoning had not occurred earlier.
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PMID:Survival test of submersible life support systems. 1 83

Eight subjects exercised on an ergometer until exhaustion. Femoral venous blood was analyzed for lactate, pyruvate, protein, electrolytes, and acid-base parameters. Muscle samples taken during the recovery period from m. quadriceps femoris were analyzed for water, electrolytes, lactate, and acid-labile CO2. Water content in the muscle biopsy sample was increased after exercise to 78.7 +/- 0.5% compared with the normal 76.7 +/- 0.8% at rest. The distribution of water between the extra- and intracellular space was calculated by the chloride method. In spite of elevated PCO2 in femoral venous blood the content of acid-labile CO2 was decreased in muscle after exercise. One minute after termination of exercise muscle CO2 was about half of the normal content at rest. During the recovery period muscle CO2 increased but was 20 min after termination of exercise still significantly below the value at rest. Intracellular pH (pHi) and bicarbonate concentration ([HCO3-]i) in muscle have been calculated. The validity of the assumptions underlying the calculations are thoroughly discussed. pHi decreased from the normal value at rest, 7.00 +/- 0.06 (mean +/- SD), to about 6.4 after exercise. [HCO3-] decreased from 10.2 +/- 1.2 mmol/l at rest to about 3 mmol/l after exercise. The changes are the greatest so far reported for an in vivo situation. After 20 min recovery pHi was almost the same as at rest, whereas bicarbonate was still well below.
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PMID:Intracellular pH and bicarbonate concentration in human muscle during recovery from exercise. 2 68

A syndrome of headache, chills, sweating, nausea, and exhaustion during and after haemodialysis is described and likened to metal fume fever. A patient has been cured of this syndrome following removal of copper-containing parts from the water-path of her home dialysis system.
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PMID:Haemodialysis and copper fever. 5 13

About 90% of the populations of North and Central Europe and North America suffer from dental caries. A change of nutrition and intensive oral hygiene would make it possible to limit the attack of caries decisively. All measures which have been directed to this end have so far failed. It must be noted that our population will apparently not be re-educated in the foreseeable future. However, since it is entitled to the exhaustion of all possibilities for the preservation of health, the increased use of fluorides for caries prevention is to be encouraged. Until the introduction of fluoridated drinking water the administration of fluoride tablets, especially in kindergartens and schools, should be promoted to the fullest extent. Alternatively it should be considered how far fluoridation of salt would be possible. Furthermore the local use of fluorides for caries prophylaxis to the fullest extent should be recommended.
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PMID:[Prevention of the caries through the application of fluoride]. 10 67

Experiments were carried out on male Wistar rats in order to clarify the leading biochemical mechanism responsible for an increase in the functional capacity of the heart. The obtained results indicate that the function of the Na,K-pump in myocardial sarcolemma is rather stable and deteriorates only during extreme exertion. The alteration of the Na,K-pump function due to a decrease in Na,K-ATP-ase activity leads to a decrease in the Na gradient and an accumulation of water in the cells which in turn reduces the capacity of the Na-Ca exchange mechanism and the rate of Ca removal from the myofibrils. Hence, the decrease in the working capacity of the heart during excessive physical exercises is primarily connected with the exhaustion of the ions active transport mechanism rather than the mechanism of aerobic energy production. In accordance with this conclusion, the functional stability of the myocardial Na,K-pump increased in our experiments with regular training, whereas the capacity to regenerate ATP via oxidative phosphorylation did not change, as demonstrated by Holloszy et al. Experiments in adrenalectomized animals, with or without administration of gluco- and mineralocorticoids, has revealed that an adequate supply of glucocorticoids to the heart is important in maintaining the function of the myocardial Na,K-pump and thereby in the working capacity of the heart during severe physical exertion.
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PMID:[Function of the sodium-potassium pump and its corticosteroid regulation as factors limiting cardiac adaptation to severe physical exertion]. 13 13

In conditions of declining water PO2, Xenopus obtains the majority of resting oxygen needs from lung breathing at 15 degrees and 25 degrees C. The critical oxygen tension was 120 +/- 9 mm Hg at 15 degrees C, and 90 +/- 10 mm Hg at 25 degrees C. During 30 min stimulation of activity to complete exhaustion at 15 degrees C, frogs exhibited an aerobic capacity of 1.7 microliter O2.g-1.h-1 and accumulated 2.22 mg lactate . g-1. Following activity these animals exhibited an oxygen debt of 49.2 microliter O2.g-1. At 25 degrees C, Xenopus had an aerobic capacity of 16.1 microliter O2.g-1 and accumulated 1.94 mg lactate . g-1. Following activity, 25 degrees C frogs exhibited an oxygen debt of 261.9 microliter O2.g-1. Thus at 15 degrees C, Xenopus acquires 85% of the ATP used during a bout of sustained exhaustive activity from anaerobic sources, and 98% at 25 degrees C. Recovery from exhaustive activity was complete after 5 h at 25 degrees C and 9 h at 15 degrees C. Comparison of these data with those of other amphibians stimulated to sustained activity suggests that aquatic amphibians can tolerate a larger lactate load than can terrestrial forms.
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PMID:Aerobic and anaerobic contributions to sustained activity in Xenopus laevis. 51 65

The hazards experienced by fun runners in Sydney's The Sun City-to-Surf run are principally physical, environmental and medical. The organizers of the event, advised by a representative of the Australian Sports Medicine Federation (N.S.W.), have progressively increased the implementation of the recommendations which were made after the inaugural run in 1971 in the areas of improved organization, competitor education, medical support, recording of competitor data, and conducting the event in cool weather. To ensure the maximum safety of the runners, the number of whom has increased from approximately 1650 in 1971 to 16200 in 1979, additional measurees have been taken. These were (i) the introduction of "spotters" with experience in sports medicine to identify and advise exhausted runners before they collapse; (ii) staffing the run's medical centre with medical and nursing specialists in intensive care; (iii) improved management of heat exhaustion; and (iv) conducting education seminars after the run to make recommendations for improving subsequent events. Since 1971, there has been a progressive reduction in the number of casualties. The incidence of casualties treated in the medical centre fell from 1.76% in 1971 to 0.1% in 1979; and the incidence of those requiring further treatment in hospital fell from 0.42% in 1971 to 0.01% in 1979. None of the participants had suffered severe complications of heat exhaustion. Improvements in the management of heat exhaustion (the most common cause of collapse) which made the use of iced water (hiterto traditional method of cooling casualties with hyperthermia) unnecessary have reduced the risk of using electrical equipment in wet surroundings. The over-all reduction in the incidence and morbidity of collapse casualties is due to a combination of factors. These factors and possibilities of further reduction of hazards are discussed.
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PMID:Reducing the hazards in Sydney's the Sun City-to-Surf runs, 1971 to 1979. 52 71

Twenty-four oxygen exposures lasting 80 to 271 min were performed by six immersed exercising subjects at 25 fsw (1.76 ATA) in both warm and cold water. Two types of exercise were performed, moderate work (50 watts) for long periods of time, and graded exercise (25-150 watts) lasting 85 min. In 21 degrees C water, moderate exercise lasted 228 +/- 39 min, with a mean VO2 of 1.72 +/- 0.11 liter/min. In 4 degree C water, the duration was 163 +/- 22 min, with a mean VO2 of 1.83 +/- 0.16 liter/min. The differences in duration of oxygen exposure in warm and cold water reflect termination at an inspired PCO2 of 7.6 mmHg, a level reached earlier in cold water because of CO2 absorbent exhaustion. In 21 degrees C water, the VO2 for graded exercise ranged from 1.51 to 3.00 liter/min and in 4 degrees C water, from 2.00 to 3.16 liter/min. Central nervous system oxygen toxicity was not observed during these exposures, although two divers had clinical and spirometric evidence of early pulmonary oxygen toxicity. The absence of CNS oxygen toxicity is attributed to low resistance and minimization of dead space, which caused a low inspired PCO2, although the divers' experience with oxygen diving and their excellent physical condition may have contributed as well.
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PMID:Prolonged oxygen exposures in immersed exercising divers at 25 fsw (1.76 ATA). 53 63

Eight male and female students were studied during exercise to exhaustion on a bicycle ergometer at 80 and 100% of Vo2max following the ingestion of water (W), 75 g of glucose (G) or a liquid meal (M) (10 g protein, 12.5 g fat, 15 g CHO). When compared to the endurance ride (80% Vo2max) in the W treatment, endurance performance time was reduced by 19%, (p less than .05) (53.2 to 43.2 min) as a result of the preexercise glucose feeding (Trial G). No difference in performance at 80% Vo2max was found between the W and M trials. The preexercise feedings had no effect on exercise time to exhaustion at 100% Vo2max. During the G and M trials at 80% Vo2max, most of the subjects demonstrated a transient decline in serum glucose (less than 3.5 mM). After 30-40 min. of exercise, however, serum glucose returned to normal and was seldom low at the time of exhaustion. Serum free fatty acids (FFA) were depressed throughout the G trial. The results of these experiments indicate impaired lipid mobilization following CHO ingestion. The present data support our earlier findings (11) which demonstrate that glucose feedings 30-45 minutes before endurance exercise increase the rate of CHO oxidation and impede the mobilization of FFA, thereby reducing exercise time to exhaustion.
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PMID:Effects of preexercise feedings on endurance performance. 58 16

Study of the hormone content and enzyme activity in patients with hypertensive disease at rest and in various types of stimulation revealed predominance of pressor humoral systems over depressor ones. With the development of the disease, the reaction of these humoral systems to stimulation diminishes. Decrease of the renin-angiotensin-aldosterone system compensatory reaction and the prostaglandin F level in patients with stable, high arterial pressur in response to furosemide administration may be among the causes of the hypotensive and natriuretic effect of this preparation. Activization of the humoral depressor systems in the initial stage of the disease is conducive to the preservation of the water-electrolyte hemostasis in the organism and maintains the labile level of arterial pressure despite the increased activity of the natrium-retaining hormones. Exhaustion of the humoral depressor systems may be one of the causes of arterial pressure stabilization.
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PMID:[Various humoral pressor and depressor systems in hypertension]. 59 92


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