Carbon Monoxide in Alveolar Air as an Index of Exposure to Cigarette Smoke

1976 ◽  
Vol 51 (5) ◽  
pp. 495-501 ◽  
Author(s):  
R. G. Rawbone ◽  
Catherine A. Coppin ◽  
A. Guz
Keyword(s):  
Carbon Monoxide ◽  
Partial Pressure ◽  
Cigarette Smoke ◽  
Rapid Method ◽  
Vapour Phase ◽  
Alveolar Air ◽  
Direct Measurements ◽  
Index Of Exposure ◽  
The Mean ◽  
Highly Correlated

1. A rapid method for the analysis of CO in expired air has been developed, which is suitable for use in studies of smoking. 2. The Bohr equation has been used to calculate the mean alveolar CO partial pressure (Pa,co). 3. The values of Pa,co obtained are highly correlated with direct measurements of venous carboxyhaemoglobin (r = 0·96). 4. The method will distinguish between populations of smokers and non-smokers, and can allow the changes of CO in a smoker throughout a 12 h period to be followed. It provides a measure of the dose of cigarette smoke (vapour phase) that results from smoking a single cigarette.

Effect of varying alveolar oxygen partial pressure on diffusing capacity for nitric oxide and carbon monoxide, membrane diffusing capacity and lung capillary blood volume

1991 ◽  
Vol 81 (6) ◽  
pp. 759-765 ◽  
Author(s):  
C. D. R. Borland ◽  
Y. Cox
Keyword(s):  
Nitric Oxide ◽  
Carbon Monoxide ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Diffusing Capacity ◽  
Pulmonary Capillary ◽  
Capillary Blood Volume ◽  
Novel Method ◽  
The Mean ◽  
Alveolar Oxygen

1. To examine the effect of varying oxygen partial pressure (Pao2) on nitric oxide (DLNO) and carbon monoxide (DLCO) diffusing capacity (transfer factor), 10 subjects performed combined DLCO/DLNO measurements with the inspired mixture made up with three different oxygen concentrations (25%, 18% and 15%) to give Pao2 values of 12–20 kPa. 2. A novel method is described for calculating membrane diffusing capacity (DM) and pulmonary capillary volume (Qc) from DLNO and DLCO. 3. The mean DMCO was 52.89 mmol min−1 kPa−1 and Qc was 0.056 litre. Reducing Pao2 from 20 to 12 kPa resulted in an increase in DLCO = −0.124 (O2%) + 11.67 (P < 0.001) and a fall in DLNO = 0.538 (O2%) + 32.01 (P < 0.001) and a fall in DLNO/DLCO = 0.107 (O2%) + 2.52 (P < 0.001). DM (P = 0.59) and Qc (P = 0.64) also tended to fall with falling Pao2. 4. It appears more likely that the minor reduction in DLNO that we have observed with falling Pao2 is due to diffusion rather than reaction limitation.

scholarly journals Double Sampling to Estimate Density and Population Trends in Birds

The Auk ◽  
2002 ◽  
Vol 119 (1) ◽  
pp. 36-45 ◽  
Author(s):  
Jonathan Bart ◽  
Susan Earnst
Keyword(s):  
Rapid Method ◽  
Double Sampling ◽  
Detection Rates ◽  
Point Counts ◽  
Actual Density ◽  
Detection Ratio ◽  
The Mean ◽  
Highly Correlated ◽  
Northern Alaska ◽  
Double Observer

Abstract We present a method for estimating density of nesting birds based on double sampling. The approach involves surveying a large sample of plots using a rapid method such as uncorrected point counts, variable circular plot counts, or the recently suggested double-observer method. A subsample of those plots is also surveyed using intensive methods to determine actual density. The ratio of the mean count on those plots (using the rapid method) to the mean actual density (as determined by the intensive searches) is used to adjust results from the rapid method. The approach works well when results from the rapid method are highly correlated with actual density. We illustrate the method with three years of shorebird surveys from the tundra in northern Alaska. In the rapid method, surveyors covered ∼10 ha h–1 and surveyed each plot a single time. The intensive surveys involved three thorough searches, required ∼3 h ha–1, and took 20% of the study effort. Surveyors using the rapid method detected an average of 79% of birds present. That detection ratio was used to convert the index obtained in the rapid method into an essentially unbiased estimate of density. Trends estimated from several years of data would also be essentially unbiased. Other advantages of double sampling are that (1) the rapid method can be changed as new methods become available, (2) domains can be compared even if detection rates differ, (3) total population size can be estimated, and (4) valuable ancillary information (e.g. nest success) can be obtained on intensive plots with little additional effort. We suggest that double sampling be used to test the assumption that rapid methods, such as variable circular plot and double-observer methods, yield density estimates that are essentially unbiased. The feasibility of implementing double sampling in a range of habitats needs to be evaluated.

A Smoking Machine Attachment for the Analysis of Carbon Monoxide, Carbon Dioxide and Nitric Oxide in the Vapour Phase of Cigarette Smoke

1975 ◽  
Vol 8 (3) ◽  
Author(s):  
E. M. Cumming
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Cigarette Smoke ◽  
Vapour Phase

AbstractAn eight-channel smoking attachment for the collection of the vapour phase from cigarettes has been developed. The utilisation of the device for the simultaneous puff by puff measurement of carbon monoxide, carbon dioxide and nitric oxide is described. The attachment has been constructed for use with the CSM 300 smoking machine but could readily be adapted for use with other smoking machines.

scholarly journals The causes of absorption of oxygen by the lungs (Preliminary communication)

1910 ◽  
Vol 82 (556) ◽  
pp. 331-333
Keyword(s):  
Carbon Monoxide ◽  
Partial Pressure ◽  
Oxygen Pressure ◽  
Diffusion Theory ◽  
The Body ◽  
Mass Action ◽  
Arterial Oxygen ◽  
Partial Pressure Of Oxygen ◽  
Alveolar Air ◽  
Arterial Blood

It has for long been a subject of controversy among physiologists whether the absorption of oxygen through the walls of the lung alveoli into the blood occurs simply by diffusion or by an active physiological process analogus to glandular secretion. Pflüger, Fredericq, and, quite recently, Krogh, have brought forward experimental evidence in favour of the diffusion theory, while Bohr, and Haldane and Lorrain Smith have supported the secretory theory, which was originally suggested by Ludwig. If the partial pressure of oxygen is ever greater in the arterial blood leaving the lungs than in the air of the lung alveoli, it is clear that the simple diffusion theory must fall to the ground; and the experiments hitherto made have been designed to ascertain whether or not the oxygen pressure in the arterial blood is ever greater than in the alveolar air. Bohr, Fredericq, and Krogh have with this object employed improved forms of Pflüger’s well-known “aerotonometer,” the instrument finally devised by Krogh being very perfect of its king. Haldane and Lorrain Smith’s method depends upon the following facts:—When blood is brought into prolonged and intimate contact with a mixture of carbon monoxide and air the hæmoglobin of the blood-corpuscles combines partly with the oxygen and partly with the carbon monoxide, the final proportions (which can be easily and accurately determined) depending, in accordance with the laws of mass-action, on the relative partial pressures of the oxygen and carbon monoxide, and on a constant. Hence, if the final proportions, the constant, and the partial pressure of the carbon monoxide are known, the partial pressure of the oxygen can be accurately deduced. By supplying to an animal air containing a fixed proportion of carbon monoxide, until the final saturation of its hæmoglobin with carbon monoxide is reached, the partial pressure of oxygen in its arterial blood can be calculated on the same principle. If the arterial oxygen pressure is greater than that of the alveolar air the final saturation of the hæmoglobin with carbon monoxide will be less than that of blood saturated with the same air outside the body, and vice versâ . It is, of course, assumed that carbon monoxide diffuses freely through the body, since, apart from its property of combining with the hæmoglobin, it is, as was experimentally shown by Haldane, a physiologically indifferent gas, like nitrogen or hydrogen.

Detection of Circulating Tissue Factor and Factor VII in a Normal Population

1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Normal Population ◽  
Mean Value ◽  
Factor Vii ◽  
Significant Difference ◽  
Age Dependent ◽  
The Mean ◽  
Highly Correlated ◽  
And Gender

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

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