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41.
Diane L. Spitler Steven M. Horvath Kando Kobayashi Jeames A. Wagner 《European journal of applied physiology》1980,43(2):157-166
Summary Twelve subjects completed a progressive treadmill test to maximal aerobic capacity while breathing air or a 79% helium — 21% oxygen gas mixture (HeO2). Metabolic and thermoregulatory responses to work while breathing the two mixtures were compared at rest, 30–40%, 60–70%, and 85–95% of maximal performance, and at maximal effort. Ventilation, ventilatory equivalent, and respiratory rates were increased and oxygen uptakes decreased by breathing HeO2 when the level of work exceeded 85–95% of maximum. Heat loss through the respiratory tract was greater breathing HeO2. The reduction in maximal oxygen uptake is probably due to a reduction in the oxygen cost of breathing a less dense gas. It was not related to a lower body temperature and probably not to O2 transport or circulatory limitation. HeO2 breathing had no effect on maximal mechanical work capacity.The nature and purpose of the study and the risks involved were explained verbally and given on a written form to each subject prior to his or her voluntary consent to participate. The protocol and procedures for this study have been approved by the Committee on Activities Involving Human Subjects, of the University of California, Santa Barbara, California, USA 相似文献
42.
In acute experiments on cats, the working capacity of the leg muscles during stimulation of the sciatic nerve was increased after division of the sciatic and femoral nerves. This effect was not due to changes in the circulation, for it persisted if the blood flow was stabilized. Increased working capacity was also manifested after partial deafferentation of the limb by division of the dorsal roots of the spinal cord or extirpation of the tibial bone marrow.Laboratory of Experimental Physiology, Latvian Research Institute of Experimental and Clinical Medicine, Riga. (Presented by Academician V. N. Chernigovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 79, No. 2, pp. 6–8, February, 1975. 相似文献
43.
The effects of cycle racing on pulmonary diffusion capacity and left ventricular systolic function 总被引:1,自引:0,他引:1
Stickland MK Petersen SR Haykowsky MJ Taylor DA Jones RL 《Respiratory physiology & neurobiology》2003,138(2-3):291-299
The purpose of this study was to examine the effects of a 20 km cycle race (TT) on left ventricular (LV) systolic and pulmonary function in 12 endurance cyclists. Spirometry, single-breath diffusion capacity (DLCO) with partitioning of membrane (DM) and capillary blood volume (Vc) components and 2-D echocardiograms were performed before and after the TT. During the TT mean oxygen consumption was 3.79 +/- 0.5 L x min(-1) (83 +/- 5.5% of VO2max) and mean blood lactate was 8.4 +/- 2.4 mM. Following the TT, spirometry values were unchanged, however, DLCO and DM were significantly (P<0.05) reduced. LV systolic function was increased (P<0.05) immediately after exercise, while end-diastolic area was decreased (P<0.05) at all points during recovery. The reduction in DM was correlated with LV systolic function following the TT. This relationship suggests a cardiovascular contribution to pulmonary diffusion impairment following exercise. 相似文献
44.
45.
Johns DP Berry D Maskrey M Wood-Baker R Reid DW Walters EH Walls J 《European journal of applied physiology》2004,93(1-2):96-101
The diffusing capacity of the lung for carbon monoxide (DLCO) decreases to below the pre-exercise value in the hours following a bout of intense exercise. Two mechanisms have been proposed: (1) development of pulmonary oedema and (2) redistribution of central blood volume to peripheral muscles causing a reduction in pulmonary capillary blood volume (Vc). In the present study DLCO, Vc and the membrane diffusing capacity (Dm) were measured in nine healthy females using a rebreathing method, in contrast to the single breath technique employed in previous studies. DLCO, Vc and Dm were measured before and at 1, 2, 3, 16 and 24 h following maximal treadmill exercise. Compared with pre-exercise values, DLCO was depressed by up to 8.9 (3.0)% (P<0.05) for the first 3 h following exercise, but had returned to pre-exercise values by 16 h post-exercise. Vc fell by 21.2 (4.1)% (P<0.05) at 3 h post-exercise, but at the same time Dm increased by 14.7 (9.1)%. It was concluded that: (1) the increase in Dm made it unlikely that the fall in DLCO was due to interstitial oedema and injury to the blood gas barrier; (2) on the other hand, the reduction in DLCO following exercise was consistent with a redistribution of blood away from the lungs; and (3) the trend for Dm and Vc to reciprocate one another indicates a situation in which a fall in Vc nevertheless promotes gas transfer at the respiratory membrane. It is suggested that this effect is brought about by the reorientation of red blood cells within the pulmonary capillaries following exercise. 相似文献
46.
Tetsuya Yoshida Seiichi Nakai Akira Yorimoto Takashi Kawabata Taketoshi Morimoto 《European journal of applied physiology》1995,71(2-3):235-239
We measured the aerobic capacity, sweat rate and fluid intake of trained athletes during outdoor exercise and examined the relationship between aerobic capacity and thermoregulatory responses at high ambient temperatures. The maximal aerobic capacity (
) of the subjects, nine male baseball players of college age, was determined by maximal exercise tests on a cycle ergometer. The subjects practised baseball regularly without drinking fluids from 1330 to 1530 hours. After 30 min rest, they played a baseball game with free access to a sports drink at 15°C from 1600 to 1830 hours. At a mean ambient temperature of 36.7 (SEM 0.2)°C, the mean percentage of body mass loss (m
b) and increase of oral temperature (T
o) from 1330 to 1530 hours was 3.47 (SEM 0.12)% and 0.81 (SEM 0.14)°C, respectively. The sweat loss from 1330 to 1830 hours was 56.53 (SEM 1.56)ml · kg–1 of body mass (M
b) while the mean fluid consumption was 44.78 (SEM 2.39)ml · kg–1 ofm
b, with recovery of 76.08 (SEM 2.81)% of sweat loss. The
was significantly inversely correlated withm
b, fluid intake and rehydration amount, but showed no correlation withT
o. These results would suggest that at a given exercise intensity in subjects with a higher aerobic capacity body temperature is maintained with a lower sweating rate than that in subjects with a lower aerobic capacity. 相似文献
47.
Paolo Santicioli Rainer Gamse Carlo Alberto Maggi Alberto Meli 《Naunyn-Schmiedeberg's archives of pharmacology》1987,335(5):580-587
Summary 1. The effect of streptozotocin (STZ) induced diabetes on rat urinary bladder function was investigated by means of in vivo cystometry and in vitro recording of bladder strips contractility. A group of sucrose-fed animals was included to determine to what extent the STZ-induced changes were ascribable to the increased diuresis. 2. After 7–9 weeks from STZ injection there was a marked increase in weight of bladder and ureters. Cystometry revealed a marked increase in bladder capacity (volume threshold) although pressure threshold and amplitude of micturition contraction were unaffected. Sucrose-fed animals, having normal blood glucose levels but a similar increase in urine production exhibited cystometric changes identical to those of STZ animals. 3. In vitro experiments indicated that the response to field stimulation (0.1–20 Hz) is reduced in STZ-pretreated but increased in sucrose-fed animals, as compared to controls. 4. The content of urinary bladder and ureters in sensory neuropeptides (substance-P, neurokinin-A and calcitonin-gene related peptide-like immunoreactivity) was increased by STZ diabetes when values were corrected for the increased weight of these organs. 5. The capsaicin-induced contraction of the rat isolated bladder strips, presumably caused by neuropeptides released from intramural sensory nerves, is unaffected by STZ diabetes. 6. These findings indicate that STZ diabetes produces, at an early stage, changes similar to those reported to occur in the human disease, e. g. a greater bladder capacity with unimpaired voiding function. The increased bladder capacity of STZ-rats seems largely, if not solely, ascribable to changes in physical properties of the detrusor muscle, thereby allowing accomodation of greater than normal volumes with similar increase of intraluminal pressure. No sign of diabetic neuropathy of the capsaicin-sensitive sensory nerves can be observed at this stage (7–9 weeks) of STZ diabetes.
Send offprint requests to P. Santicioli at the above address 相似文献
48.
J. Smolander V. Louhevaaral P. Oja 《International archives of occupational and environmental health》1984,54(4):295-302
Summary Ninety to ninety-five men (aged 27 to 46 years) from the police academy were the study subjects. Their prior habits of physical excercise, estimated aerobic capacity (
), muscular performance, and thickness of subcutaneous fat were determined. The policemen were taller (181 cm vs 175 cm) and heavier (84 kg vs 74 kg) than the average 20- to 40-year-old Finnish man, and their
(1 · min–1) was higher (3.41 1 · min–1 vs 2.96 1 min–1 The frequency of prior physical exercise significantly correlated with most of the variables studied. Those policemen who did not exercise at all (n = 12) were inferior to the average 20- to 40-year-old Finnish man on all the physical fitness tests, whereas the results of the most active policemen (n = 23) were clearly higher. The results indicate that the selection of heavier and taller men for police training guarantees a certain absolute level of physical performance capacity. However, the physical activity involved in police work is insufficient to maintain a high level of physical fitness, which must be achieved through participation in regular and effective physical training. 相似文献
49.
Feike J. Loots Daan Smulders Paul Giesen Rogier M. Hopstaken Marleen Smits 《The European journal of general practice》2021,27(1):83
BackgroundSigns of the systemic inflammatory response syndrome (SIRS) – fever (or hypothermia), tachycardia and tachypnoea – are used in the hospital setting to identify patients with possible sepsis.ObjectivesTo determine how frequently abnormalities in the vital signs of SIRS are present in adult out-of-hours (OOH) primary care patients with suspected infections and assess the association with acute hospital referral.MethodsWe conducted a cross-sectional study at the OOH GP cooperative in Nijmegen, the Netherlands, between August and October 2015. GPs were instructed to record the body temperature, heart rate and respiratory rate of all patients with suspected acute infections. Vital signs of SIRS, other relevant signs and symptoms, and referral state were extracted from the electronic registration system of the OOH GP cooperative retrospectively. Logistic regression analysis was used to evaluate the association between clinical signs and hospital referral.ResultsA total of 558 patients with suspected infections were included. At least two SIRS vital signs were abnormal in 35/409 (8.6%) of the clinic consultations and 60/149 (40.3%) of the home visits. Referral rate increased from 13% when no SIRS vital sign was abnormal to 68% when all three SIRS vital signs were abnormal. Independent associations for referral were found for decreased oxygen saturation, hypotension and rapid illness progression, but not for individual SIRS vital signs.ConclusionAlthough patients with abnormal vital signs of SIRS were referred more often, decreased oxygen saturation, hypotension and rapid illness progression seem to be most important for GPs to guide further management. 相似文献
50.
César Cuevas-Lara Mikel Izquierdo Mikel L. Sáez de Asteasu Robinson Ramírez-Vélez Fabiola Zambom-Ferraresi Fabricio Zambom-Ferraresi Nicolás Martínez-Velilla 《Journal of the American Medical Directors Association》2021,22(2):364-371.e1
ObjectivesTo examine the effectiveness of game-based interventions compared with usual care on health-related outcomes for acutely hospitalized older patients.DesignSystematic review of randomized controlled trials (RCT) and nonrandomized trials.Setting and ParticipantsAdults aged 65 years or older admitted to an Acute Care for Elderly unit were selected.MeasuresHealth-related outcomes (eg, functional capacity, quality of life, adherence to treatment).ResultsFour RCTs were included in the review. The interventions were based on the implementation of serious-game programs using Nintendo Wii in acute medical patients. Across the included studies, no significant differences were observed between groups on functional capacity and health-related quality of life. Significant differences were found between groups on the adherence to treatment (in favor of the control group), but no differences were obtained in other outcomes such as enjoyment and motivation.Conclusions and ImplicationsIn general, there is very limited evidence for the efficacy to reach conclusions about the effects of game-based interventions on health-related outcomes in acutely hospitalized older patients. Future studies are needed to improve our knowledge in the field; however, we consider that these strategies should be considered in the future complementary to usual care. 相似文献