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Romer Lee M - - 2006
The effect of exercise-induced arterial hypoxemia (EIAH) on quadriceps muscle fatigue was assessed in 11 male endurance-trained subjects [peak O2 uptake (VO2 peak) = 56.4 +/- 2.8 ml x kg(-1) x min(-1); mean +/- SE]. Subjects exercised on a cycle ergometer at >or=90% VO2 peak) to exhaustion (13.2 +/- 0.8 ...
Marino Franca - - 2006
Migration and superoxide anion (O2-) generation were studied in polymorphonuclear leukocytes (PMNs) from 14 athyreotic patients, previously treated by total thyroidectomy and radioiodine therapy for differentiated thyroid carcinoma, and from age- and sex-matched euthyroid healthy controls. Patients were studied twice: in hypothyroidism (visit 1) and after TSH-suppressive L-T4 replacement therapy ...
Kemming Gregor I - - 2005
Perfluorocarbon (PFC) emulsions are intravascular oxygen therapeutics that temporarily enhance tissue oxygenation in dilutional anemia. However, PFC emulsions are not resuscitation fluids because PFCs only work optimally in the presence of high O2 partial pressure (hyperoxia); moreover, because they have no oncotic potential, dosing limitations prevent their use to permanently ...
Shykoff B E - - 2005
Elevated inspired oxygen partial pressures (PO2) may cause pulmonary oxygen toxicity (PO2T). However, normal variability and water immersion also cause pulmonary function (PF) changes. In 21 subjects, we measured the variability of flow-volume parameters and diffusing capacity for carbon monoxide (DLCO) for six weeks without diving. In 24 divers, we ...
Muth Claus-Martin - - 2005
Apnea diving is a fascinating example of applied physiology. The record for apnea diving as an extreme sport is 171 meters, 8:58 minutes. The short time beneath the surface induces profound cardiovascular and respiratory effects. Variations of blood-gas tensions result from the interaction of metabolism and the rapid sequence of ...
Krause Daniel J - - 2005
Nitric oxide (NO) is a physiological mediator of skeletal muscle function. Specifically, NO affects cellular respiration and muscle contractility; however, the reduced blood flow and convective O2 delivery that result from impaired vasodilatation when NO synthase (NOS) is inhibited in vivo have obscured past interpretations of the effects of NO. ...
Witte Klaus K A - - 2005
The kinetics of oxygen and carbon dioxide at the onset of and recovery from exercise are slowed in patients with chronic heart failure (CHF). The aim of the present study was to establish whether the kinetics of O2 are influenced by the work rate. Thirteen CHF patients and 12 control ...
Boamfa E I - - 2005
BACKGROUND AND AIMS: This paper examines the basis of the greater tolerance of an indica rice cultivar FR13A to complete submergence compared with relatively intolerant japonica rice CT6241. We study whether this superior tolerance is related to its greater tolerance to O2 shortage and to an ability to run a ...
Dujić Zeljko - - 2005
PURPOSE: Decompression sickness is initiated by the formation of gas bubbles in tissue and blood if the divers return to surface pressure too fast. The effect of exercise before, during, and after dive on bubble formation is still controversial. We have reported recently that strenuous aerobic exercise 24 h before ...
Fernández A - - 2005
A study of the lesions of beaked whales (BWs) in a recent mass stranding in the Canary Islands following naval exercises provides a possible explanation of the relationship between anthropogenic, acoustic (sonar) activities and the stranding and death of marine mammals. Fourteen BWs were stranded in the Canary Islands close ...
Pilmanis Andrew A - - 2005
BACKGROUND: Many aircraft oxygen systems do not deliver 100% O2. Inert gases can be present at various levels. The purpose of this study was to determine the effect of these inert gas levels on decompression sickness (DCS). METHODS: Subjects were exposed for 4 h to 5486 m (18,000 ft) with ...
Blatteau Jean-Eric - - 2005
BACKGROUND: A single bout of aerobic exercise 24 h before a dive significantly reduces the formation of circulating venous gas emboli (VGE) on decompression. The purpose of this investigation was to determine the effect of aerobic exercise 2 h before a dive. METHODS: There were 16 trained military divers who ...
Green J A - - 2005
Macaroni penguins were implanted with data loggers to record heart rate (fH), abdominal temperature (Tab) and diving depth during their pre-moult trip (summer) and winter migration. The penguins showed substantial differences in diving behaviour between the seasons. During winter, mean and maximum dive duration and dive depth were significantly greater ...
Muth Thomas - - 2005
It should be investigated whether the traditional dependency between respiratory and systemic measures is preserved during scuba diving, and whether the diving experience would affect respiration. Additionally, respiration data were analyzed for gender differences (118 sports divers). Respiratory variables were assessed at poolside and during diving in the pool. The ...
Grataloup Olivier - - 2005
This study focuses on the effect of hyperoxia on maximal oxygen uptake VO2max and maximal power (Pmax) in subjects exhibiting exercise-induced arterial hypoxemia (EIH) at sea level. Sixteen competing male cyclists VO2max > 60 ml.min(-1).kg(-1)) performed exhaustive ramp exercise (cycle-ergometer) under normoxia and moderate hyperoxia (FIO2 = 30%). After the ...
Nishiyama Osamu - - 2005
STUDY OBJECTIVE: In COPD, it has been shown that peripheral muscle dysfunction is a factor determining exercise intolerance. We examined the hypothesis that exercise capacity of patients with idiopathic pulmonary fibrosis (IPF) is, at least in part, determined by peripheral muscle dysfunction. METHODS: Maximum oxygen uptake (V(O2)max) was evaluated in ...
Dujic Z - - 2005
OBJECTIVE: To evaluate the cardiopulmonary effects of open sea scuba air diving to 39 m (30 minutes bottom time) with standard decompression. To account for possible gravity dependent effects of venous gas bubbles, the variables were measured in different post-dive body postures and compared with the baseline values before the ...
Mortensen Stefan P - - 2005
Reductions in systemic and locomotor limb muscle blood flow and O2 delivery limit aerobic capacity in humans. To examine whether O2 delivery limits both aerobic power and capacity, we first measured systemic haemodynamics, O2 transport and O2 uptake during incremental and constant (372 +/- 11 W; 85% of peak power; ...
McKone Edward F - - 2005
We tested the hypothesis that maximal exercise performance in adults with cystic fibrosis is limited by arterial hypoxemia. In study 1, patients completed two maximal exercise tests, a control and a test with 400 ml of added dead space. Maximal O2 consumption was significantly lower in the added dead space ...
Dujić Zeljko - - 2005
Paradoxical arterializations of venous gas emboli can lead to neurological damage after diving with compressed air. Recently, significant exercise-induced intrapulmonary anatomical shunts have been reported in healthy humans that result in widening of alveolar-to-arterial oxygen gradient. The aim of this study was to examine whether intrapulmonary shunts can be found ...
Roberts Claire L - - 2005
The purpose of this study was to characterise, for the first time, the pulmonary O2 uptake (V(O2)) on-kinetic responses to step transitions to moderate and heavy intensity rowing ergometer exercise, and to compare the responses to those observed during upright cycle ergometer exercise. We hypothesised that the recruitment of a ...
Greenlee Kendra J - - 2005
The respiratory system of growing caterpillars is challenged in two distinct ways as they develop from hatchlings to fifth instars preparing for pupation. First, across instars, body sizes and tracheal lengths increase substantially. Second, within each instar, animal mass can more than double while major tracheal respiratory system structures, such ...
Halsey Lewis G - - 2005
We measured the effects of exposure to hypoxia (15% and 11% oxygen) and hypercapnia (up to 4.5% carbon dioxide) on rates of respiratory gas exchange both between and during dives in tufted ducks, Aythya fuligula, to investigate to what extent these may explain changes in diving behaviour. As found in ...
Scherhag Armin - - 2005
STUDY PURPOSE: The aim of this study was to investigate the cardiopulmonary status in a competitive apnea diving team. DESIGN: This study was conducted with a cross-sectional study design in which subjects had to undergo a predefined series of cardiopulmonary examinations. SUBJECTS: Eight competitive apnea divers (mean age, 26.9 +/- ...
Hooker Sascha K - - 2005
Novel observations collected from video, acoustic and conductivity sensors showed that Antarctic fur seals consistently exhale during the last 50-85% of ascent from all dives (10-160 m, n > 8000 dives from 50 seals). The depth of initial bubble emission was best predicted by maximum dive depth, suggesting an underlying ...
Ferreira Leonardo F - - 2005
In rat muscle, faster dynamics of microvascular P(O2) (approximately blood flow (Q(m) to O2 uptake (V(O2) ratio) after prior contractions that did not alter blood [lactate] have been considered to be a consequence of faster V(O2) kinetics. However, in humans, prior exercise below the lactate threshold does not affect the ...
Shibata Masahiro - - 2005
To examine the effects of vascular tone reduction on O2 consumption of the vascular wall, we determined the O2 consumption rates of arteriolar walls under normal conditions and during vasodilation induced by topical application of papaverine. A phosphorescence quenching technique was used to quantify intra- and perivascular PO2 in rat ...
Winslow Robert M - - 2005
We have proposed new criteria for a successful cell-free, hemoglobin-based O2 carrier. These include increased molecular radius, increased viscosity, increased oncotic pressure, and reduced p50. A new molecule, MalPEG-Hb, formulated at 4.2g/dL in lactated Ringer's solution (MP4), has been produced according to these new criteria. MP4 has a p50 of ...
Eynan Mirit - - 2005
Elevated arterial Pco(2) (hypercapnia) has a major effect on central nervous system oxygen toxicity in diving with a closed-circuit breathing apparatus. The purpose of the present study was to follow up the ability of divers to detect CO(2) and to determine the CO(2) retention trait after 1 year of active ...
Borg Kim A - - 2004
Lesser scaup ducks were trained to dive for short and long durations following exposure to various gas concentrations to determine the influence of oxygen (O2) and carbon dioxide (CO2) on diving behavior and heart rate. Compared with normoxia, hyperoxia (50% O2) significantly increased the duration of long dives, whereas severe ...
Clark T D - - 2005
The majority of information concerning the cardio-metabolic performance of varanids during exercise is limited to a few species at their preferred body temperature (T(b)) even though, being ectotherms, varanids naturally experience rather large changes in T(b). Although it is well established that absolute aerobic scope declines with decreasing T(b), it ...
Lovvorn James R - - 2004
Loggers were attached to free-ranging Brünnich's guillemots Uria lomvia during dives, to measure swim speeds, body angles, stroke rates, stroke and glide durations, and acceleration patterns within strokes, and the data were used to model the mechanical costs of propelling the body fuselage (head and trunk excluding wings). During vertical ...
Castellini Michael A - - 2004
The field of marine mammal diving biochemistry was essentially untouched when Peter Hochachka turned his attention to it in the mid-1970s. Over the next 30 years, his work followed three main themes in this area: first, most biologists at that time supported the theory that diving mammals utilized enhanced metabolic ...
Sato Katsufumi - - 2004
It is generally assumed that air-breathing aquatic animals always choose the shortest route to minimize duration for transit between the surface and foraging depth in order to maximize the proportion of time spent foraging. However, empirical data indicate that the body angles of some diving animals are rarely vertical during ...
Froget G - - 2004
The main objective of this study was to determine heart rate (fh) and the energetic costs of specific behaviours of king penguins while ashore and while foraging at sea during their breeding period. In particular, an estimate was made of the energetic cost of diving in order to determine the ...
McKenzie D J - - 2004
Teleost fish possess discrete blocks of oxidative red muscle (RM) and glycolytic white muscle, whereas tetrapod skeletal muscles are mixed oxidative/glycolytic. It has been suggested that the anatomy of RM in teleost fish could lead to higher intramuscular O2 partial pressures (PO2) than in mammalian skeletal muscles. This study provides ...
Munkeby Berit H - - 2004
Perinatal asphyxia is a major cause of immediate and postponed brain injury in the newborn. We hypothesized that resuscitation with 100% O2 compared with ambient air is detrimental to the cerebral tissue. We assessed cerebral injury in newborn piglets that underwent global hypoxia and subsequent resuscitation with 21 or 100% ...
Koppo Katrien - - 2004
PURPOSE: To test the hypothesis that pharmacological activation of the pyruvate dehydrogenase enzyme complex (PDC) with dichloroacetate (DCA) would speed phase II pulmonary oxygen uptake ((.-)V(O2)) kinetics after the onset of subsequent moderate-intensity (40-45% ((.-)V(O2)) peak) cycle exercise. METHODS: Seven healthy males (mean +/- SD age 25 +/- 4 yr, ...
Mourtzakis M - - 2004
To elucidate the potential limitations on maximal human quadriceps O2 capacity, six subjects trained (T) one quadriceps on the single-legged knee extensor ergometer (1 h/day at 70% maximum workload for 5 days/wk), while their contralateral quadriceps remained untrained (UT). Following 5 wk of training, subjects underwent incremental knee extensor tests ...
Jankowski Louis W - - 2004
BACKGROUND: Exercise and diving have generally been associated with an increased risk of decompression sickness (DCS), thus accounting for the lack of studies involving exercise during decompression. However, theoretical and observational evidence contrary to this association motivated the present investigation on the effects of moderate, intermittent exercise during diving and/or ...
Haseler Luke J - - 2004
Previously, it was demonstrated in exercise-trained humans that phosphocreatine (PCr) recovery is significantly altered by fraction of inspired O2 (FI(O2)), suggesting that in this population under normoxic conditions, O2 availability limits maximal oxidative rate. Haseler LJ, Hogan ML, and Richardson RS. J Appl Physiol 86: 2013-2018, 1999. To further elucidate ...
Wilson Rory P - - 2004
Air-breathing animals diving to forage can optimize time underwater by diving with just enough oxygen for the projected performance underwater. By so doing they surface with minimal body oxygen levels, which leads to maximal rates of oxygen uptake. We examined whether imperial cormorants Phalacrocorax atriceps adhere to this by examining ...
Zerm M - - 2004
We studied whether oxygen uptake from the surrounding water might enhance survival in submerged third instar larvae of Phaeoxantha klugii, a tiger beetle from the central Amazonian floodplains. Local oxygen partial pressures (Po(2)) were measured with microcoaxial needle electrodes close to larvae submerged in initially air-saturated still water. The Po(2) ...
Teppema Luc J - - 2004
Low intravenous dose acetazolamide causes a decrease in steady-state CO(2) sensitivity of both the peripheral and central chemoreflex loops. The effect, however, on the steady-state hypoxic response is unknown. In the present study, we measured the effect of 4 mg x kg(-1) acetazolamide (i.v.) on the isocapnic steady-state hypoxic response ...
McCole Steve D - - 2004
We sought to determine whether common genetic variations at the beta2 (beta2-AR, Gln27Glu) and beta3 (beta3-AR, Trp64Arg) adrenergic receptor gene loci were associated with cardiovascular (CV) hemodynamics during maximal and submaximal exercise. CV hemodynamics were assessed in 62 healthy postmenopausal women (20 sedentary, 22 physically active, and 20 endurance athletes) ...
Dujic Zeljko - - 2004
We have previously shown in a rat model that a single bout of high-intensity aerobic exercise 20 h before a simulated dive reduces bubble formation and after the dive protects from lethal decompression sickness. The present study investigated the importance of these findings in man. Twelve healthy male divers were ...
Wisløff Ulrik - - 2004
Nitrogen dissolves in the blood during dives, but comes out of solution if divers return to normal pressure too rapidly. Nitrogen bubbles cause a range of effects from skin rashes to seizures, coma and death. It is believed that these bubbles form from bubble precursors (gas nuclei). Recently we have ...
Karatani Hajime - - 2004
Yellow-emitting Vibrio fischeri Y1 modulates its bioluminescence (BL) depending on the dissolved O2 concentration. On supplying O2 to the cells under anaerobiosis, the cells begin to emit striking yellow BL peaking around 535 nm. The enhanced yellow emission reverts reversibly to the original level after O2 is consumed. Moreover, the ...
Marroni A - - 2004
In spite of many modifications to decompression algorithms, the incidence of decompression sickness (DCS) in scuba divers has changed very little. The success of stage, compared to linear ascents, is well described yet theoretical changes in decompression ratios have diminished the importance of fast tissue gas tensions as critical for ...
Reeves John T - - 2004
Although an increase in hemoglobin concentration [Hb] in high altitude residents assists oxygen transport, excessive polycythemia ([Hb] > or = 21 g/100 mL) may cause the syndrome of chronic mountain sickness (CMS). A recent theoretical analysis has suggested that increasing [Hb] above 18 g/100 mL provides no further benefit in ...
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