Apparatus for monitoring the oxygen uptake and carbon dioxide production of fermentations

1966 ◽  
Vol 8 (4) ◽  
pp. 539-548 ◽  
Author(s):  
A. L. Jensen ◽  
J. S. Schultz
1965 ◽  
Vol 25 (2) ◽  
pp. 123-128 ◽  
Author(s):  
Nirmal Chakravarty

Glycolytic activity of rat peritoneal mast cells has been measured by the Cartesian ampulla diver technique. The rates of anaerobic glycolysis, expressed as CO2 expelled from a bicarbonate medium, are 1.70 x 10-6 µl and 1.43 x 10-6 µl per cell per hour with and without glucose, respectively. The aerobic glycolysis rate in the presence of glucose, assuming the respiratory quotient to be 1, is 0.93 x 10-6 µl CO2 per cell per hour. It is pointed out that the anaerobic and non-respiratory aerobic carbon dioxide production by mast cells is much higher than the respiratory oxygen uptake reported previously. These values have been interpreted in terms of glucose utilization.


2007 ◽  
Vol 13 (6) ◽  
pp. 462-469 ◽  
Author(s):  
Ross Arena ◽  
Jonathan Myers ◽  
Leon Hsu ◽  
Mary Ann Peberdy ◽  
Sherry Pinkstaff ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Lee Ingle ◽  
Rebecca Sloan ◽  
Sean Carroll ◽  
Kevin Goode ◽  
John G. Cleland ◽  
...  

Introduction. The relation between minute ventilation (VE) and carbon dioxide production (VCO2) can be characterised by the instantaneous ratio of ventilation to carbon dioxide production, the ventilatory equivalent for CO2(VEqCO2). We hypothesised that the time taken to achieve the lowest VEqCO2(time to VEqCO2 nadir) may be a prognostic marker in patients with chronic heart failure (CHF).Methods. Patients and healthy controls underwent a symptom-limited, cardiopulmonary exercise test (CPET) on a treadmill to volitional exhaustion.Results. 423 patients with CHF (mean age years; 80% males) and 78 healthy controls (62% males; age years) were recruited. Time to VEqCO2 nadir was shorter in patients than controls ( s versus  s; ). Univariable predictors of all-cause mortality included peak oxygen uptake (), VEqCO2nadir (), and time to VEqCO2nadir (). In an adjusted Cox multivariable proportional hazards model, peak oxygen uptake () and VEqCO2nadir () were the most significant independent predictors of all-cause mortality.Conclusion. The time to VEqCO2nadir was shorter in patients with CHF than in normal subjects and was a predictor of subsequent mortality.


2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
David Sinning ◽  
Mario Kasner ◽  
Dirk Westermann ◽  
Karsten Schulze ◽  
Heinz-Peter Schultheiss ◽  
...  

Aims. Several mechanisms can be involved in the development of exercise intolerance in patients with heart failure despite normal left ventricular ejection fraction (HFNEF) and may include impairment of left ventricular (LV) stiffness. We therefore investigated the influence of LV stiffness, determined by pressure-volume loop analysis obtained by conductance catheterization, on exercise capacity in HFNEF.Methods and Results. 27 HFNEF patients who showed LV diastolic dysfunction in pressure-volume (PV) loop analysis performed symptom-limited cardiopulmonary exercise testing (CPET) and were compared with 12 patients who did not show diastolic dysfunction in PV loop analysis. HFNEF patients revealed a lower peak performance (), breathing reserve (), and ventilation equivalent for carbon dioxide production at rest (). LV stiffness correlated with peak oxygen uptake (, ), peak oxygen uptake at ventilatory threshold (, ), and ventilation equivalent for carbon dioxide production at ventilatory threshold (, ).Conclusions. CPET parameters such as peak oxygen uptake, peak oxygen uptake at ventilatory threshold, and ventilation equivalent for carbon dioxide production at ventilatory threshold correlate with LV stiffness. Increased LV stiffness impairs exercise capacity in HFNEF.


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