Noninvasive quantitative measurement of myocardial and whole-body oxygen consumption using MRI: initial results

2009 ◽  
Vol 27 (2) ◽  
pp. 147-154 ◽  
Author(s):  
Yuesong Yang ◽  
Warren D. Foltz ◽  
Naeem Merchant ◽  
Jeffrey A. Stainsby ◽  
Graham A. Wright
Keyword(s):  
Oxygen Consumption ◽  
Quantitative Measurement ◽  
Whole Body ◽  
Initial Results

scholarly journals Initial results from a prototype whole-body photon-counting computed tomography system

2015 ◽  
Author(s):  
Z. Yu ◽  
S. Leng ◽  
S. M. Jorgensen ◽  
Z. Li ◽  
R. Gutjahr ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Photon Counting ◽  
Whole Body ◽  
Tomography System ◽  
Initial Results

scholarly journals Association between Oxygen Consumption and Surface Electromyographic Amplitude and Its Variation within Individual Calf Muscles during Walking at Various Speeds

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1748
Author(s):  
Kohei Watanabe ◽  
Shideh Narouei
Keyword(s):  
Oxygen Consumption ◽  
Spatial Variation ◽  
Metabolic Response ◽  
Correlation Coefficients ◽  
Surface Emg ◽  
Medial Gastrocnemius ◽  
Whole Body ◽  
Young Males ◽  
Emg Amplitude ◽  
Calf Muscles

Surface electromyography (EMG) has been used to estimate muscle work and physiological burden of the whole body during human movements. However, there are spatial variations in surface EMG responses within individual muscles. The aim of this study was to investigate the relation between oxygen consumption and surface EMG responses of lower leg muscles during walking at various speeds and to quantify its spatial variation within an individual muscle. Nine young males walked on a treadmill at four speeds: preferred minus 1 km/h, preferred, preferred plus 1 km/h, and preferred plus 2 km/h, and the metabolic response was measured based on the expired gas. High-density surface EMG of the tibialis anterior (TA), medial gastrocnemius (MG), lateral gastrocnemius, and soleus muscles was performed using 64 two-dimensional electrode grids. Correlation coefficients between oxygen consumption and the surface EMG amplitude were calculated across the gait speeds for each channel in the electrode grid and for individual muscles. Mean correlation coefficients across electrodes were 0.69–0.87 for the four individual muscles, and the spatial variation of correlation between the surface EMG amplitude and oxygen consumption within an electrode grid was significantly greater in MG muscle than in TA muscle (Quartile deviations: 0.24 for MG and 0.02 for TA, p < 0.05). These results suggest that the physiological burden of the whole body during gait at various speeds can be estimated from the surface EMG amplitude of calf muscles, but we need to note its spatial distribution within the MG muscle.

Metabolic responses of the whole body, portal-drained viscera and hindquarter to adrenaline infusion: Effects of nonselective and selective β-adrenoceptor blockade

1997 ◽  
Vol 77 (2) ◽  
pp. 307-316 ◽  
Author(s):  
J. O. O. Miaron ◽  
R. J. Christopherson
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Portal Vein ◽  
Influencing Factor ◽  
External Iliac Artery ◽  
Open Circuit ◽  
Whole Body ◽  
Organ Blood Flow ◽  
Β Blocker ◽  
Β Blockers

Propranolol, a nonselective β-blocker and selective β-blockers (metoprolol a β1-blocker and ICI 118551 a β2-blocker) were used to investigate the β-adrenoceptor-mediated adrenaline-induced increase in whole-body and organ VO2 in five whether sheep. Transit time blood flow probes were chronically implanted on the portal vein and the external iliac artery and sampling catheters were placed in the mesenteric artery, iliac vein and portal vein. Oxygen consumption by the whole body was measured by open circuit calorimetry, and oxygen consumption by the portal-drained viscera and the hindquarter was determined from A-VO2 differences and organ blood flow. Absolute pre-infusion VO2 values for the whole body, portal-drained viscera and hindquarters were 236 ± 7.4, 61 ± 6.0 and 13 ± 3.1 mL min−1 respectively. The mean changes in VO2 in response to infusion were 74 vs. 11, 26, 10 and 12 mL min−1 (SE = 9.1) for whole body; 31 vs. −2, −15, 13 and −4 mL min−1 (SE = 7.3) for portal-drained viscera and 8 vs. −0.4, 2.1, 1.0 and −2.7 mL min−1; SE = 4.3) for hindquarters during adrenaline, control, propranolol, metoprolol and ICI 118551 treatments, respectively. Adrenaline increased VO2 (P < 0.05) in the whole body and portal-drained viscera, but not hindquarters relative to controls. All β-blockers suppressed (P < 0.05) the adrenaline-induced increase in VO2 except for the portal-drained viscera where metoprolol was less effective and the hindquarters where β-blockers had no effect. The blood flow pattern was similar to VO2 responses for the portal-drained viscera. The nonselective β1 and β2 blockers were effective in reducing the adrenaline-induced increases in blood flow from the portal-drained viscera and to the hindquarters, with more pronounced β-adrenoceptor-mediated haemodynamic effects. The results indicate that the β-adrenoceptor system modulates whole body VO2, clearly establishes that adrenaline induces an increased VO2 in portal-drained viscera which can be reversed by a β2 or nonselective β blocker and implicates β adrenoceptors as an influencing factor in the maintenance energy requirements of ruminants. Key words: Calorimetry, adrenaline, β blockers, blood flow, sheep

Whole body oxygen consumption and critical oxygen delivery in response to prolonged and severe carbon monoxide poisoning

Resuscitation ◽  
2003 ◽  
Vol 56 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Howard A Smithline ◽  
Kevin R Ward ◽  
Donald A Chiulli ◽  
Heidi C Blake ◽  
Emanuel P Rivers
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Consumption ◽  
Oxygen Delivery ◽  
Carbon Monoxide Poisoning ◽  
Whole Body ◽  
Critical Oxygen

scholarly journals Maximal Fat Oxidation: Comparison between Treadmill, Elliptical and Rowing Exercises

2021 ◽  
pp. 170-178
Author(s):  
Michelle Filipovic ◽  
Stephanie Munten ◽  
Karl-Heinz Herzig ◽  
Dominique D. Gagnon
Keyword(s):  
Oxygen Consumption ◽  
Venous Blood ◽  
Maximal Oxygen Consumption ◽  
Blood Gases ◽  
Fat Oxidation ◽  
Peak Oxygen Consumption ◽  
Whole Body ◽  
Mixed Venous Blood ◽  
Exercise Modality ◽  
Maximal Fat Oxidation

Fat oxidation during exercise is associated with cardio-metabolic benefits, but the extent of which whole-body exercise modality elicits the greatest fat oxidation remains unclear. We investigated the effects of treadmill, elliptical and rowing exercise on fat oxidation in healthy individuals. Nine healthy males participated in three, peak oxygen consumption tests, on a treadmill, elliptical and rowing ergometer. Indirect calorimetry was used to assess maximal oxygen consumption (V̇O2peak), maximal fat oxidation (MFO) rates, and the exercise intensity MFO occurred (Fatmax). Mixed venous blood was collected to assess lactate and blood gases concentrations. While V̇O2peak was similar between exercise modalities, MFO rates were higher on the treadmill (mean ± SD; 0.61 ± 0.06 g·min-1) compared to both the elliptical (0.41 ± 0.08 g·min-1, p = 0.022) and the rower (0.40 ± 0.08 g·min-1, p = 0.017). Fatmax values were also significantly higher on the treadmill (56.0 ± 6.2 %V̇O2peak) compared to both the elliptical (36.8 ± 5.4 %V̇O2peak, p = 0.049) and rower (31.6 ± 5.0 %V̇O2peak, p = 0.021). Post-exercise blood lactate concentrations were also significantly lower following treadmill exercise (p = 0.021). Exercising on a treadmill maximizes fat oxidation to a greater extent than elliptical and rowing exercises, and remains an important exercise modality to improve fat oxidation, and consequently, cardio-metabolic health.

scholarly journals Developmental changes in oxygen consumption regulation in larvae of the South African clawed frog Xenopus laevis

1995 ◽  
Vol 198 (12) ◽  
pp. 2465-2475 ◽  
Author(s):  
D Hastings ◽  
W Burggren
Keyword(s):  
Oxygen Consumption ◽  
Lactic Acid ◽  
Xenopus Laevis ◽  
South African ◽  
Acute Hypoxia ◽  
Lactate Concentration ◽  
Aerobic Metabolism ◽  
Whole Body ◽  
Lactate Levels ◽  
Clawed Frog

Well-developed larval Xenopus laevis (NF stages 58&shy;66) are oxygen regulators, at least during mild hypoxia. When and how they change from oxygen conformers (the presumed condition of the fertilized egg) to oxygen regulators is unknown. Also unknown is how anaerobic metabolic capabilities change during development, especially in response to acute hypoxia, and to what extent, if any, anaerobiosis is used to supplement aerobic metabolism. Consequently, we have investigated resting rates of oxygen consumption (M.O2) and concentrations of whole-body lactate (lactic acid) during development in normoxia and in response to acute hypoxia in Xenopus laevis. M.O2 increased in an episodic, non-linear fashion during development. Resting, normoxic M.O2 increased about tenfold (to approximately 0.20 &micro;mol g-1 h-1) between NF stages 1&shy;39 and 40&shy;44, and then another tenfold between NF stages 45&shy;48 and 49&shy;51 (to approximately 2.0 &micro;mol g-1 h-1), remaining at about 2 &micro;mol g-1 h-1 for the remainder of larval development. M.O2 reached its highest level in newly metamorphosed frogs (nearly 4 &micro;mol g-1 h-1), before decreasing to about 1.0 &micro;mol g-1 h-1 in large adults. X. laevis embryos and larvae up to NF stage 54&shy;57 were oxygen conformers when exposed to variable levels of acute hypoxia. The only exception was NF stage 45&shy;48 (external gills present yet body mass still very small), which showed some capability of oxygen regulation. All larvae older than stage 54&shy;57 and adults were oxygen regulators and had the lowest values of Pcrit (the oxygen partial pressure at which M.O2 begins to decline). Whole-body lactate concentration in normoxia was about 1 &micro;mol g-1 for all larval groups, rising to about 12 &micro;mol g-1 in adults. Concentrations of lactic acid in NF stages 1&shy;51 were unaffected by even severe ambient hypoxia. However, whole-body lactate levels in NF stages 52&shy;66 increased in response to severe hypoxia, indicating that some anaerobic metabolism was being used to supplement diminishing aerobic metabolism. The largest increases in concentration of lactate occurred in late larvae and adults.

Oxygen Consumption Following Whole-Body X-Irradiation of Guinea Pigs

1952 ◽  
Vol 81 (1) ◽  
pp. 140-141 ◽  
Author(s):  
F. Smith ◽  
W. G. Buddington ◽  
M. M. Grenan
Keyword(s):  
Oxygen Consumption ◽  
Guinea Pigs ◽  
Whole Body ◽  
X Irradiation

Cardio-respiratory ontogeny during chronic carbon monoxide exposure in the clawed frog Xenopus laevis.

1998 ◽  
Vol 201 (9) ◽  
pp. 1461-1472 ◽  
Author(s):  
P R Territo ◽  
W W Burggren
Keyword(s):  
Oxygen Consumption ◽  
Xenopus Laevis ◽  
Lactate Concentration ◽  
Respiratory Physiology ◽  
Whole Body ◽  
O2 Transport ◽  
Rate Of Oxygen Consumption ◽  
Stage 1 ◽  
Clawed Frog ◽  
Individual Mass

The present study investigates the ontogeny of cardio-respiratory physiology in Xenopus laevis where O2 transport is obstructed. Animals were raised from eggs (NF stage 1) to metamorphic climax (NF stage 63), while maintained either in air or in chronic 2 kPa CO, which functionally ablates O2 transport by hemoglobin (Hb). Whole-animal rate of oxygen consumption (.MO2), whole-body lactate concentration, individual mass, heart rate (fh) and stroke volume (Vs) were measured. Additionally, cardiac output (.Q) and the ratio of the rate of oxygen consumption to the total rate at which oxygen is transported in the blood (.MO2/.QO2) were calculated to determine limitations imparted when O2 transport is impaired. Our data on early development suggest that the onset of convective blood flow occurs prior to the absolute need for convection to supplement diffusive transport. Values for .MO2, whole-body lactate concentration, mass and fh did not differ significantly between controls and CO-exposed animals. However, CO-exposed animals showed a significant (P&lt;0.05) increase in Vs, .MO2/.QO2 and .Q compared with controls. These results indicate that limiting blood O2 transport is not deleterious to metabolism and development as a whole and that convective oxygen transport via Hb is not essential for normal cardiovascular or respiratory function during larval development.

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