Search Results
Results 401 - 450 of 990
< 4 5 6 7 8 9 10 11 12 13 14 >
Nakata K - - 2000
Two types small and efficient ECMO oxygenators were developed utilizing the most up to date hollow fiber technology. Newly silicone hollow fibers possess sufficient mechanical strength while maintaining ultra thin walls of 50 micro meter. Two types of oxygenators were made with this fiber. The fiber length for the type ...
Tschischka K - - 2000
The rates of oxygen uptake of the marine polychaete Nereis pelagica and the bivalve Arctica islandica depend on the availability of ambient oxygen. This is manifest both at the tissue level and in isolated mitochondria studied between oxygen tensions (P(O2)) of 6.3 and 47.6 kPa (47-357 mmHg). Oxyconformity was found ...
Nakamura M - - 2000
Mixed venous oxygen saturation (SvO2) has been proposed as one of the suitable parameters for physiologic control of a total artificial heart (TAH). To establish the practical application of SvO2, we investigated the response of cardiac output (CO) and SvO2 to step-loaded exercise. A normal calf was surgically equipped with ...
Sigalevich P - - 2000
A chemostat coculture of the sulfate-reducing bacterium Desulfovibrio oxyclinae and the facultatively aerobic heterotroph Marinobacter sp. strain MB was grown for 1 week under anaerobic conditions at a dilution rate of 0.05 h(-1). It was then exposed to an oxygen flux of 223 micromol min(-1) by gassing the growth vessel ...
Guyatt G H GH Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, - - 2000
Almost every country in the developed world has a domiciliary oxygen program. Whether recipients meet program criteria has not been rigorously studied. Cross-sectional survey. Two hundred thirty-seven patients receiving domiciliary oxygen in the Ontario Ministry of Health Home Oxygen Program (HOP). A respiratory therapist visited the patients' homes and administered ...
Aquino-Parsons C - - 2000
BACKGROUND AND PURPOSE: To assess the effect of inhalation of various high oxygen content gases (HOCG) with different carbon dioxide concentrations on the tumour oxygen tension in patients with primary gynaecological malignancies. MATERIALS AND METHODS: Tumour oxygen tension was assessed on two protocols in those patients with locally advanced visible ...
Gnaiger E - - 2000
Mitochondria are confronted with low oxygen levels in the microenvironment within tissues; yet, isolated mitochondria are routinely studied under air-saturated conditions that are effectively hyperoxic, increase oxidative stress, and may impair mitochondrial function. Under hypoxia, on the other hand, respiration and ATP supply are restricted. Under these conditions of oxygen ...
Bangsbo J - - 2000
The present study examined the onset and the rate of rise of muscle oxidation during intense exercise in humans and whether oxygen availability limits muscle oxygen uptake in the initial phase of intense exercise. Six subjects performed 3 min of intense one-legged knee-extensor exercise [65.3 +/- 3.7 (means +/- SE) ...
Plaut I - - 2000
Specimens of the euryhaline cyprinodontid fish, Aphanius dispar, collected in salt ponds, were acclimated to salinities of <1 (freshwater), 35 (seawater), 70, 105, and 140 ppt for 4 wk before measurement of oxygen consumption, critical swimming speed, and routine activity level. Oxygen consumption was similar in <1, 35, and 70 ...
Baba R - - 2000
Oxygen uptake efficiency slope is a new index of cardiorespiratory functional reserve derived from the logarithmic relation between oxygen uptake (VO(2)) and minute ventilation during incremental exercise. The oxygen uptake efficiency slope represents how effectively oxygen is extracted and taken into the body from the air, and then ventilated. The ...
Revill S M - - 2000
In a prospective, randomized study we examined the effect of (i) ambulatory oxygen and (ii) a portable, inspiratory pressure support (IPS) device on the endurance shuttle walk test (ESWT) in patients with severe chronic obstructive pulmonary disease (COPD). Ten outpatients [median (range) FEV1 0.60 l(0.35, 1.45)] performed the ESWT under ...
Agarwal K S - - 2000
The text book of Pediatric Advanced Life Support of the American Heart Association recommends that a reservoir is used with a self inflating bag valve device. The figure in the book suggests that if such a device is connected to an oxygen supply, the oxygen will fill the bag first ...
Eckmann D M - - 2000
Tracheal insufflation of oxygen has at least three major uses for chronic oxygen supplementation through a percutaneous catheter, it is an adjunctive measure to enhance gas exchange during mechanical ventilation, and it provides an emergency therapy for oxygen delivery with upper airway obstruction. In this article the mechanisms of gas ...
Reybrouck T - - 2000
OBJECTIVE: To assess the relation between exercise intensity and oxygen uptake during graded exercise in paediatric patients who underwent surgical repair of congenital heart disease, and to compare it with conventional measures of aerobic exercise function. DESIGN: Cross sectional study. Exercise testing was performed on a treadmill and gas exchange ...
Berkowitz B A - - 2000
PURPOSE: To test the hypothesis that after supplemental oxygen recovery (SOR) in the newborn rat model of retinopathy of prematurity (ROP) the preretinal neovascular (NV) incidence and severity are decreased and the panretinal oxygenation ability is improved. METHODS: Newborn rats were first raised in either room air (controls) or variable ...
Arthur P G - - 2000
Oxygen conformance can be described as the ability to reduce energy demand, and hence oxygen consumption, in response to a decline in oxygen availability without a decrease in the concentration of ATP. It has been proposed that oxygen conformance may enhance cellular survival at low oxygen concentrations. We demonstrate that ...
Mitra S - - 2000
Phosphorescence quenching of certain metalloporphyrins is used to measure tissue and microvascular pO(2). Oxygen quenching of metalloporphyrin triplet states creates singlet oxygen, which is highly reactive in biological systems, and these oxygen-consuming reactions are capable of perturbing tissue oxygenation. Kinetics of photochemical oxygen consumption were measured for a Pd-porphyrin in ...
Doherty M - - 2000
The aim of this study was to determine the reproducibility of the maximal accumulated oxygen deficit and the associated exercise time to exhaustion during short-distance running. Fifteen well-trained males (mean +/- s: VO2max = 58.0+/-4.6 ml x kg(-1) x min(-1)) performed the maximum accumulated oxygen deficit test at an exercise ...
Hedenstierna G - - 2000
Atelectasis is a frequent finding in paralysed and mechanically ventilated patients. Atelectasis, causing shunt, impairs oxygenation and could contribute to postoperative pulmonary complications. Pre-oxygenation used during anaesthesia induction causes atelectasis. A lowering of oxygen fraction from 100% to 80% does not shorten the safety time of apnoea period, particularly useful ...
Bangsbo J - - 2000
This review presents data on human muscle oxygen consumption in the initial phase of exercise as well as on muscle maximal oxygen uptake. It also discusses mechanistic limiting factors related to oxygen utilization at the onset of exercise and of maximal aerobic power of skeletal muscle. Direct measurements of oxygen ...
Kondo M - - 2000
Reactive oxygen species are regarded as a possible cause of many diseases. However, there are few reports offering in vivo and in situ proof of the direct involvement of reactive oxygen species in the pathogenesis of disease. In the present study, the luciferin derivative 2-methyl-6-[4-methoxyphenyl]-3,7-dihydroimidazo [1,2-alpha] pyrazin-3-one (MCLA) was used ...
Bae S Y - - 2000
The two purposes of the present study were 1) to determine the oxygen consumption in working skeletal muscle from the oxygenation measured by near-infrared continuous-wave spectroscopy (NIRcws) with the arterial occlusion method during the resting condition, INT(VT), and INT(MAX) and 2) to examine whether the decline rate of oxygenation is ...
Li J - - 2000
OBJECTIVE: We sought to assess oxygen consumption and its determinants in children shortly after undergoing cardiopulmonary bypass operations. METHODS: Twenty children, aged 2 months to 15 years (median, 3.75 years), undergoing hypothermic cardiopulmonary bypass operations were studied during the first 4 hours after arrival in the intensive care unit. Central ...
MacIntyre N R - - 2000
Lung disease affects exercise performance through a number of mechanisms, including hypoxemia, abnormal ventilatory mechanics, abnormal ventilatory muscles, abnormal ventilatory patterns, abnormal right heart function and subjective dyspnea. Supplemental oxygen improves hypoxemia and thus improves exercise impairment resulting from hypoxemia-related reductions in oxygen delivery. Supplemental oxygen also reduces exercise ventilation. ...
Stefanova D - - 2000
Short (up to 60 s) supramaximal (about 400 W on the average) exercise is accompanied by specific biochemical processes in the working muscles and by a general increase in energy metabolism. Outwardly, this is manifested by an excess post-exercise oxygen consumption (EPOC). Since its actual measurement is time consuming and ...
Burioka N - - 2000
It is well known that conventional bubbling humidifiers are capable of producing micro-aerosols contaminated with bacteria. We developed a unique humidifier, named a membrane humidifier, that does not require an external water supply. This new system obtains moisture from room air. We investigated the clinical and in vitro evaluation of ...
Chown S L - - 2000
It has been suggested that discontinuous gas exchange cycles (DGCs) in insects evolved in response to hypoxic and/or hypercapnic environments, and that the flutter phase of the DGC is predominantly diffusive. We tested these hypotheses by examining the rate of CO(2) release at a declining series of oxygen partial pressures ...
Criner G J - - 2000
In general, based on the above studies of the effects of supplemental oxygen on reducing mortality and improving sleep and exercise function in certain patient groups, patients whose disease is stable on a full medical regimen with PaO2 < or = 55 mm Hg (SaO2 < or = 88%) should ...
Stücker M - - 2000
In skin lesions of chronic venous incompetence (CVI) transcutaneous oxygen pressure (tcpO(2)) at the ankle is often reduced. However, in some CVI patients the tcpO(2) during suprasystolic occlusion remains significantly higher than in healthy subjects. The aim of the present study was to investigate which kind of CVI patients develop ...
Russell S D - - 1999
Recent uncontrolled studies have suggested improved maximal exercise capacity and decreased exercise ventilation in heart failure after administration of increased inspired oxygen concentrations. To study the responses further, 16 patients performed staged, symptom-limited cycle ergometry with humidified 21% and 60% inspired oxygen concentrations using a randomized, double-blind, crossover study design. ...
Scott C B - - 1999
Above the lactate/ventilatory threshold, prolonged steady-state exercise produces a secondary rise in oxygen uptake, the slow oxygen component. The slow oxygen component 'represents an additional energetic requirement' above steady state; however, a lack of consensus on how to measure anaerobic energy expenditure makes it difficult to ascertain how or if ...
Malley K S - - 1999
Fire departments have replaced traditional uniforms with modern, more thermal protective gear. Although the new uniforms afford superior burn protection, they may reduce work time. Our purpose was to determine if exercise time was (1) reduced by wearing the modern versus traditional uniform, and (2) increased by a design change ...
di Prampero P E - - 1999
This paper discusses under an energetic perspective the recent and older evidence supporting the classical notion that the 'oxygen debt', as originally defined by Margaria et al. (1933) [Am. J. Physiol. 106, 689-714], consists of two major components: the alactic oxygen debt, with a half-time of the order of 30 ...
Colier W N WN Department of Physiology (237), Faculty of Medical Sciences, University of Nijmegen, P.O. Box 9101, NL-6500 HB Nijmegen, The Netherlands. - - 1999
Near-infrared spectroscopy (NIRS) was used to assess human motor-cortex oxygenation changes in response to cyclic coupled movements of hand and foot. Using a highly sensitive NIRS instrument, we showed that it was possible to detect reproducible oxygenation patterns using single cycles (20 s) of easy and difficult association tasks. No ...
McCully K K - - 1999
The purpose of this study was to determine if chronic fatigue syndrome (CFS) is associated with reduced oxygen delivery to muscles. Patients with CFS according to CDC (Center for Disease Control) criteria (n=20) were compared with normal sedentary subjects (n=12). Muscle oxygen delivery was measured as the rate of post-exercise ...
Primosch R E - - 1999
PURPOSE: The purpose of this study was to determine the influence of 40% nitrous oxide/60% oxygen inhalation with scavenging on the behavioral and physiological parameters during routine pediatric dental procedures. METHODS: Twenty-two subjects, aged 60-116 months, were randomized into a double blind, cross-over study design and administered alternately either 40% ...
Mukherjee J - - 1999
On-line monitoring of NAD(P)H fluorescence and 2D fluorescence spectroscopy was performed with Enterobacter aerogenes, a bacterium sensitive to oxygen availability. The organism was grown in a reactor under low and high dissolved oxygen concentrations and circulated through a bypass attached to the reactor. Under low dissolved oxygen concentration in the ...
Nakamura M - - 1999
We developed a control of the total artificial heart (TAH) using mixed venous oxygen saturation (SvO2). With this method, the TAH output was controlled by automatically adjusting drive parameters in response to changes in measured SvO2. The feasibility and validity of this method were evaluated in a series of treadmill ...
Takeda T - - 1999
We determined aerial and aquatic oxygen uptake rates (&Mdot;o(2)) of Periophthalmodon schlosseri at rest and after exhaustive exercise at 30 degrees C. Resting &Mdot;o(2) in air (3.16 +/- 0.10 [SE] &mgr;mol/g/hr) was significantly higher than that in air saturated water (2.41 +/- 0.06 &mgr;mol/g/hr). When the fish was placed in ...
Neri M - - 1999
As liquid oxygen represents a relevant burden on healthcare systems, different methods have been developed to reduce oxygen consumption, including economizers. The aims of the study were: 1) to evaluate the efficacy of an economizer device (Companion 5 Oxygen Saver) in a significant sample of patients, and 2) to perform ...
Barja G - - 1999
Studies in heart and nonsynaptic brain mitochondria from two mammals and three birds show that complex I generates oxygen radicals in heart and nonsynaptic brain mitochondria in States 4 and 3, whereas complex III does it only in heart mitochondria and only in State 4. The increase in oxygen consumption ...
Veasey D A - - 1999
This study measured oxygen concentrations of air within totally encapsulating chemical-protective (TECP) suits during simulated hazardous materials emergency response operations. This was done to allow assessment of the suitability of use of air within TECP suits as an emergency air supply during escapes from contaminated areas following loss of primary ...
Zhao G - - 1999
In addition to regulating vascular tone, there is increasing evidence for the involvement of NO in the modulation of oxygen consumption. Our in-vitro studies indicated that exogenous and endogenous NO reduces the consumption of oxygen in isolated canine skeletal and cardiac muscle, which is probably related to its direct effect ...
Gallez B - - 1999
Using the broadening of the electron paramagentic resonance (EPR) linewidth of paramagnetic particles by oxygen, it is possible to make measurements of the partial pressure of oxygen in vivo. While the results obtained so far with EPR oximetry are very encouraging, several paramagnetic materials may lose their responsiveness to oxygen ...
Wilkes A R - - 1999
A breathing system filter can remain connected to a laryngeal mask airway during recovery from anaesthesia. The Luer-lock monitoring port on the filter could be used for the delivery of supplementary oxygen. The efficacy of this technique was assessed in vitro by comparing the performance of two filters with four ...
Moriyama S - - 1999
We hypothesized that patients who have undergone hypothermic cardiopulmonary bypass may have abnormal oxygen metabolism after cardiac surgery because of oxygen debts that occurred during cardiopulmonary bypass. A prospective study was designed to determine oxygen consumption and carbon dioxide production using an indirect calorimeter in 45 adult patients who underwent ...
Carraway M S - - 1999
That hyperoxia induces "a profound modification in the metabolism of tissues" is an old observation. The mechanisms by which the physiologic, pathologic, and biomechanical perturbations caused by oxygen relate to the in vivo manifestations of oxygen toxicity, however, have not been explained fully. This article reviews cellular mechanisms of toxicity, ...
Nishiyasu T - - 1999
During the application of a wide range of graded lower body pressures (LBP) (-50 to 50 mmHg), we examined how (1) the tissue oxygenation in the lower and upper parts of the body changes at rest, and (2) how tissue oxygenation changes in the lower extremities during dynamical leg exercise. ...
Capellier G - - 1999
Normobaric oxygen toxicity is well described in all animal species. However susceptibility to oxygen exposure is highly variable according to age, species and strains. Similarly in humans, prolonged high oxygen exposure is reported to induce cough, shortness of breath, decrease vital capacity and increase alveolo-capillary permeability. The toxic FIO2 threshold ...
Piantadosi C A - - 1999
Carbon monoxide (CO) poisoning is a common occurrence in today's society. Most such poisonings are a direct consequence of inhaling the toxic byproducts of combustion. Exposure to toxic amounts of CO occurs most often during inhalation of automobile exhaust or smoke resulting either from faulty heating systems or industrial accidents. ...
< 4 5 6 7 8 9 10 11 12 13 14 >