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)

Although the environmental stresses to which man is subjected on the ground are less than those commonly encountered in aviation or under water, they may still exceed an individual's powers of adaptation. Extremes of temperature, commonly encountered in the Arctic or the tropics, may occur in regions of normally temperate climate and lead to failure of temperature regulation, resulting in hypothermia, frostbite, heat exhaustion, or heat stroke. High mountains impose additional hazards due to high winds and lack of oxygen, and deep mines are dangerous work-places because of high temperature and humidity. Some physiological acclimatization occurs in extreme natural environments and the dangers may be reduced by appropriate clothing, diet and behaviour.
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PMID:Adaptation and failure of adaptation to extreme natural environments. 113 66

The toxicity of FUT-187, a synthetic protease inhibitor, was investigated in Sprague-Dawley rats. FUT-187 was given orally to the rats at doses of 2, 10, 50, 250 and 1250 mg/kg/day for 13 weeks, then the drug was withdrawn for 5 weeks for recovery. The results are summarized as follows: In the 1250 mg/kg/day group, 9 out of 20 males died with decreased body weight and exhaustion. Histopathological examination revealed renal papillary necrosis, ulcer in the urinary bladder, hemostatic lesions in the lungs and liver, ulcer or erosion in the stomach, duodenum and jejunum. The surviving animals in this group showed swelling of the limbs due to synovitis, transient salivation immediately after administration, suppression of growth with decreased food consumption. Urinalysis revealed a low pH, increased ketones and bilirubin excretion, dark yellowish change in color, the appearance of "leaflet-shaped" crystals and increased red blood cells and epithelial cells in the urinary sediment, increased water intake, decreased specific gravity and decreased sodium, potassium and chloride in the urine. Hematologically, there was an increase in the white blood cell count. A biochemical analysis of the blood revealed decreased amylase activity, glucose and total protein levels and increased GOT activity and inorganic phosphorus levels. Pathological changes were observed in the pancreas, kidney, digestive tract, urinary bladder and liver. The pancreas showed macroscopical enlargement and increased organ weight. Histopathologically, there were several alterations in the acinar cells, such as vacuolization due to increased fat droplets, nuclear irregularity, prominent nucleoli, irregular arrangement and vesiculation of rough endoplasmic reticulum (rER), dilatation of developed Golgi apparatus and increased free ribosomes. In the kidney, increased weight and pigmentation in the proximal tubular epithelium were noted. Electron microscopically, these pigments were recognized as secondary lysosomes containing filamentous material and electron dense granules within a lucent matrix. In the digestive tract, ulcer or erosion in the stomach and duodenum, and villous proliferation in the small intestine were observed. Furthermore, hyperplasia and vacuolization were noted in the mucosal epithelium of the urinary bladder. In addition, loss of perilobular fat droplets in the liver and increased adrenal weight without histological change were observed. After a 5-week recovery period, these changes disappeared almost completely. In the 250 mg/kg/day group, slight suppression of growth the appearance of "leaflet-shaped" crystals in the urinary , sediment, increased water intake and decreased sodium in the urine were observed. The pancreas showed enlargement, increased weight, acinar cell hypertrophy with increased zymogen granules, fine vacuolization, slight derangement and vesicular of rER, and dilatation of Golgi apparatus.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[A 13-week subacute oral toxicity study of 6-amidino-2-naphthyl 4-[(4,5-dihydro-1H-imidazol-2-yl) amino] benzoate dimethanesulfonate (FUT-187) in rats]. 129 23

Ion adsorption and ion exchange are two methods commonly used in small home units to treat drinking water to bring the fluoride concentration to within acceptable limits. However, the necessary flowthrough system is often difficult to arrange where there is no piped supply and gradual exhaustion of the active agent is not easily detected. In an attempt to overcome these problems a defluoridation method based on the precipitation of a sparingly soluble fluoride salt, fluorapatite, has been studied. Samples of simulated high-fluoride drinking waters, approximately 10 ppm F, were saturated with brushite, resulting in a state of supersaturation with respect to fluorapatite. Subsequent seeding with hydroxyapatite caused a lowering of the calcium, phosphate, and fluoride concentrations in solution, indicative of fluorapatite precipitation. Repeating the process had an additive effect. Bone char was a less effective seed than hydroxyapatite with water containing fluoride only, but was a more effective seed with simulated Kenyan borehole water containing additional salts. Sixty-minute brushite saturation and apatite seeding steps were generally more effective than 10-min steps. The results suggest that apatite coprecipitation may be a convenient low-technology way to defluoridate drinking water, although prior testing might be useful to ensure adequate removal of fluoride.
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PMID:Partial defluoridation of drinking water using fluorapatite precipitation. 131 1

The purpose of this study was to determine oxygen uptake (VO2) at various water flow rates and maximal oxygen uptake (VO2max) during swimming in a hypobaric hypoxic environment. Seven trained swimmers swam in normal [N; 751 mmHg (100.1 kPa)] and hypobaric hypoxic [H; 601 mmHg (80.27 kPa)] environments in a chamber where atmospheric pressure could be regulated. Water flow rate started at 0.80 m.s-1 and was increased by 0.05 m.s-1 every 2 min up to 1.00 m.s-1 and then by 0.05 m.s-1 every minute until exhaustion. At submaximal water flow rates, carbon dioxide production (VCO2), pulmonary ventilation (VE) and tidal volume (VT) were significantly greater in H than in N. There were no significant differences in the response of submaximal VO2, heart rate (fc) or respiratory frequency (fR) between N and H. Maximal VE, fR, VT, fc, blood lactate concentration and water flow rate were not significantly different between N and H. However, VO2max under H [3.65 (SD 0.11) l.min-1] was significantly lower by 12.0% (SD 3.4)% than that in N [4.15 (SD 0.18) l.min-1]. This decrease agrees well with previous investigations that have studied centrally limited exercise, such as running and cycling, under similar levels of hypoxia.
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PMID:Oxygen uptake during swimming in a hypobaric hypoxic environment. 139 44

The purpose of this research was to measure changes in selected plasma amino acids (AA) during two successive exercise trials to exhaustion. Eleven trained male athletes completed these trials at weeks 4, 6, 8 and 12. Blood samples for each test were collected after a 12-hour fast at times (in minutes) 0 (Resting), 45, 90, 135, 180, at exhaustion (EI), after a 20-minute recovery period, and at the second exhaustion (EII). At the end of EI, subjects consumed an artificially sweetened water replacement (placebo) treatment or a carbohydrate (CHO) replacement (1.1 g CHO/kg BW) in order to determine any effect of CHO replacement on changes in energy substrates or AA, adjusted for plasma volume changes. From baseline to EI, alpha-aminobutyric acid, alanine, glycine, isoleucine, serine, valine threonine, and tyrosine decreased significantly (p less than or equal to 0.05), while taurine increased significantly. During the recovery period following EI, isoleucine, leucine, ornithine, phenylalanine, tyrosine, urea and valine increased significantly. From the end of recovery until EII, alanine, aspartic acid, glycine, isoleucine, leucine, ornithine, phenylalanine, serine, threonine, tyrosine and valine decreased significantly. CHO replacement had no effect on the mean change scores for any AA from EI to the end of the recovery period and affected only serine, citrulline, glycine and threonine from the end of the recovery period to EII.
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PMID:Plasma amino acid responses of trained athletes to two successive exhaustion trials with and without interim carbohydrate feeding. 145 48

This study determined whether 1) exhaustion from heat strain occurs at the same body temperatures during exercise in the heat when subjects are euhydrated as when they are hypohydrated, 2) aerobic fitness influences the body temperature at which exhaustion from heat strain occurs, and 3) curves could be developed to estimate exhaustion rates at a given level of physiological strain. Seventeen heat-acclimated men [maximal oxygen uptake (VO2max) from 45 to 65 ml.kg-1.min-1] attempted two heat stress tests (HSTs): one when euhydrated and one when hypohydrated by 8% of total body water. The HSTs consisted of 180 min of rest and treadmill walking (45% VO2max) in a hot-dry (ambient temperature 49 degrees C, relative humidity 20%) environment. The required evaporative cooling (Ereq) exceeded the maximal evaporative cooling capacity of the environment (Emax); thus thermal equilibrium could not be achieved and 27 of 34 HSTs ended by exhaustion from heat strain. Our findings concerning exhaustion from heat strain are 1) hypohydration reduced the core temperature that could be tolerated; 2) aerobic fitness, per se, did not influence the magnitude of heat strain that could be tolerated; 3) curves can be developed to estimate exhaustion rates for a given level of physiological strain; and 4) exhaustion was rarely associated with a core temperature up to 38 degrees C, and it always occurred before a temperature of 40 degrees C was achieved. These findings are applicable to heat-acclimated individuals performing moderate-intensity exercise under conditions where Ereq approximates or exceeds Emax and who have high skin temperatures.
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PMID:Human tolerance to heat strain during exercise: influence of hydration. 150 93

The effects of temperature, water and Baralyme exhaustion on the rate of disappearance of sevoflurane in Baralyme were studied in an in vitro model. We found that the rate of disappearance of sevoflurane in Baralyme increased as the temperature increased and decreased as the concentration of water increased. The disappearance of sevoflurane also decreased in the presence of exhausted Baralyme compared with fresh Baralyme. The slower rate of disappearance of sevoflurane in Baralyme in the presence of water and Baralyme exhaustion suggests that the disappearance of sevoflurane may be self-limiting in the clinical setting.
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PMID:Factors affecting the rate of disappearance of sevoflurane in Baralyme. 156 60

To investigate energy requirements in healthy elderly subjects, we assessed the association of total energy expenditure (TEE) with resting metabolic rate (RMR), physical activity, body composition, and energy intake in 13 individuals (aged 56 to 78 years, six women and seven men). Free-living TEE was measured using doubly labeled water, RMR was measured by respiratory gas analysis, and energy expenditure of physical activity (EEPA) was derived from the difference between TEE and RMR, assuming the thermic response to feeding contributes 10% of TEE. Fat mass (FM) and fat-free mass (FFM) were obtained from underwater weighing, VO2max was determined from a bicycle test to exhaustion, energy intake was obtained from a 3-day food diary, and leisure time activity (LTA) was determined by structured interview. TEE was 2,406 +/- 438 kcal/d (range, 1,856 to 3,200 kcal/d, or 1.25 to 2.11 times RMR) and was related to VO2max (r = .79, P = .001), LTA (r = .74, P = .004), FFM (r = .69, P = .009), and FM (r = -.64, P = .018). The association between TEE and VO2max persisted after adjustment for FFM (partial r = .58, P = .036). EEPA was related to LTA (r = .83, P less than .0001) and FM (r = -.58, P = .039). Energy intake underestimated TEE by 31% +/- 18% in women and by 12% +/- 11% in men. Using stepwise regression, TEE was best predicted by VO2max and LTA (total adjusted r2 = .86). We conclude the following: (1) TEE varies greatly within healthy elderly subjects due to variations in physical activity; (2) VO2max has an important role in predicting energy requirements in older individuals; and (3) healthy older individuals underreport energy intake.
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PMID:Total energy expenditure and energy requirements in healthy elderly persons. 161 93

The purpose of this study was to examine the limiting factor for swimming by measuring peak oxygen uptake (peak VO2) during front crawl (C) and arm stroke (A) under a hypobaric hypoxic condition. Seven-trained swimmers (age; 19-21 yrs, 100 m free style event; 57.2 +/- 2.5 secs) were measured twice under a normal (N) (751 mmHg) and a hypobaric hypoxic (H) (602 mmHg) condition in a chamber where atmospheric pressure was regulated. Water flow rate started at 0.80 m.sec-1 and was increased by 0.05 m.sec-1 every 2 min up to 1.00 m.sec-1. Subsequently, flow rate was increased by 0.05 m.sec-1 every minute until exhaustion. VO2 was measured with an automatic analyzer. The peak heart rate under N was not significantly different from that under H in both C (N; 190 +/- 9, H; 184 +/- 6 beats.min-1) and A (N; 180 +/- 6, H; 181 +/- 6 beats.min-1). Peak VO2 values during A (N; 3.42 +/- 0.27, H; 3.08 +/- 0.19 l.min-1) were significantly lower by 15-20% than those during C (N; 4.18 +/- 0.18, H; 3.65 +/- 0.11 l.min-1) for both N and H (p less than 0.01). Peak VO2 values under H were significantly lower than those under N during both C and A (p less than 0.01). There was no significant difference in the magnitude of decrease in peak VO2 between C (12.0 +/- 3.4%) and A (9.8 +/- 3.8%) under H. This ratio of decrease agrees with previous investigations that studied centrally limited exercise, such as running and cycling, under similar levels of hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Peak oxygen uptake during arm stroke under a hypobaric hypoxic condition. 164 26

The effects of ingesting a low dose of CHO on plasma glucose, glucoregulatory hormone responses, and performance during prolonged cycling were investigated. Nine male subjects cycled for 165 min at approximately 67% peak VO2 followed by a two-stage performance ride to exhaustion on two occasions in the laboratory. Every 20 min during exercise, subjects consumed either a flavored water placebo (P) or a dilute carbohydrate beverage (C). Blood samples were collected immediately before, every 20 min throughout, and immediately after exercise. Plasma was analyzed for glucose, lactate, free fatty acids (FFA), and various glucoregulatory hormones. VO2, RER, heart rate, perceived exertion, and exercise performance were also measured. Lactate, FFA, epinephrine, norepinephrine, ACTH, cortisol, and glucagon increased with exercise whereas glucose and insulin decreased (p < or = .05). Except for a small difference in glucose at 158 min of exercise and at exhaustion, no significant differences were found between drinks for any of the variables studied (P > or = .05). Ingestion of 13 g carbohydrate per hour is not sufficient to maintain plasma glucose, attenuate the glucoregulatory hormone response, and improve performance during prolonged moderate intensity cycling.
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PMID:Failure of low dose carbohydrate feeding to attenuate glucoregulatory hormone responses and improve endurance performance. 166 7


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