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At least 19 recordsLinked to original sources
PubMed1975

[Gaschromatographic determination of carbon monoxide and carbon dioxide. Investigations from the gas phase of cigarette smoke].

A gaschromatographic method for the quantitative determination of CO and CO2 is described. The method is suitable in a wide sensitivity range from ppm to % content of these gases. CO, CH4 and CO2 are separated under isothermic working conditions by the use of a column filled with carbon molecular sieve CMS. The column should be regenerated only after more than 1000 analyses. The quantitative determination of CO and CO2 in cigarette smoke is reported. With a total retention time of less than one min. this system enables the analysis of the carbon oxides to be performed puff by puff. The CO and CO2 contents of the vapour phase of various test cigarettes are discussed.

Carbon Dioxide↗
PubMed1975

The role of carbon monoxide in cigarette smoking. I. Carbon monoxide yield from cigarettes.

The carbon monoxide deliveries of 20 major Canadian brands of cigarettes, determined by gas chromatography and using standard smoking conditions, were estimated and found to vary by a factor of about two. The CO yields were found to increase with puff volume and tobacco moisture, decrease with increased paper porosity, but remain essentially constant with puff duration. The data suggest that reduced CO deliveries can be achieved by increasing the cigarette paper porosity. Combustion temperature presumably also influences CO deliveries, but the relative role ascribed to dilution and combustion is not clear. It may be concluded that smokers can lower their CO exposure by reducing their puff volume, smoking cigarettes manufactured from high porosity paper, by taking fewer puffs, and decreasing their tendency to inhale. Since CO and tar deliveries are correlated, these measures would also tend to decrease a smoker's exposure to tar.

Carbon Monoxide↗
PubMed1975

Influence of carbon monoxide, hypoxic hypoxia or potassium cyanide pretreatment on acute carbon monoxide and hypoxic hypoxia lethality.

Pre-exposure of mice to 500 or 1000 ppm of carbon monoxide (CO) for 4 hours resulted in a significant decrease in lethality induced by exposure to 2500 ppm of CO 24 hours later. Pre-exposure to CO had no effect on lethality induced by hypoxic hypoxia (low inspired O2 tension) or potassium cyanide (KCN). Pre-exposure to 10% O2 for 4 hours significantly decreased lethality induced 24 hours later by CO or 7% O2 exposures lethality induced 24 hours later by CO or 7% O2 exposures but had no effect on KCN-induced lethality. Pretreatment with a nonlethal dose of KCN had no significant effect on lethality induced 24 hours later by exposure to CO (2500 ppm), 7% O2 or KCN. The alterations in CO lethality were not associated with alterations in carboxyhemoglobin levels. Studies of oxygen consumption and indicators of oxygen delivery to tissues (P50 and red blood cell 2,3-diphosphoglycerate) failed to provide any evidence of pretreatment alteration. Examination of blood lactate, pyruvate and lactate/pyruvate ratios in control and pre-exposed mice after a short exposure to 2500 ppm of CO showed significantly lower lactate and lactate/pyruvate ratios in the pre-exposed mice as compared to controls. These data suggest that animals pre-exposed to 1000 ppm of CO and 10% O2 are less hypoxic than non-pre-exposed animals even through their oxygen delivery system is unchanged.

Adenosine Diphosphate↗
PubMed1979

[Serum thiocyanate level as a discriminating element in evaluation of exposure to carbon monoxide].

Blood carbon monoxide concentration levels in two groups of subjects to a different degree of exposure are examined in the light of the subjects declared smoking habits and serum thiocyanate levels. The latter parameter proved an effective pointer to individual exposure to CO due to tobacco combustion. Assessment of the results showed that it could be proposed as an indicative and discriminating test of habitual exposure to CO, so as to enable expired CO and HbCO values to be interpreted in occupationally exposed subjects.

Carbon Monoxide↗
PubMed1977

[Prevision of the hazard of acute carbon monoxide poisoning. A nomogram for calculating blood HbCO on the basis of the carbon monoxide concentration in air, the length of exposure and the lung ventilation (author's transl)].

The kinetics of carbon monoxide absorption was studied by the authors. An equation is proposed which enables to define the percentage of blood HbCO on the basis of the CO concentration in the air, the length of exposure, and the lung ventilation. The results proved to be satisfactory and were found to be comparable to the experimental data reported in the literature. A set of nomograms is reported which enables to define the blood HbCO saturation on the basis of the parameters which it depends on, therefore appearing to be very profitable to the physician in order to foresee and then prevent the hazard of acute carbon monoxide poisoning.

Air Pollution↗
PubMed1976

Oxygen affinity of human blood in presence of carbon monoxide.

If carbon monoxide is present in the blood, it is necessary to quantitate its effect on apparent O2 affinity in order to properly compute venous PO2 and P50. Ways of doing this are analyzed theoretically. The classical principles of Haldane and of Roughton and Darling are reviewed and simplified. The method of computation of PO2 in the presence of CO as introduced by Forster is shown to be in considerable error. The source of this error is determined. The error produced if the presence of CO is ignored during the computation of P50 is analyzed.

Carbon Monoxide↗
PubMed1992

Management of the moribund carbon monoxide victim.

Carbon monoxide (CO) poisoning is the commonest single cause of fatal poisoning in the U.K. (Broome & Pearson, 1988). The clinical features are numerous and include headache, fatigue, dizziness, confusion, memory loss, paraesthesia, chest pain, abdominal pain, nausea, and diarrhoea as well as coma, convulsions and death. Without adequate treatment many patients develop neuropsychiatric sequelae including headaches, irritability, memory loss, confusion and personality changes. The diagnosis of CO poisoning is often suggested only by circumstances surrounding the victim, and remains a challenge to the A&E department. Hyperbaric oxygen therapy (HBO) is internationally accepted as the most powerful form of treatment in severe cases (Drug & Therapeutics Bulletin, 1988; Lowe-Ponsford & Henry, 1989). However, in the U.K. treatment with HBO is often not considered due to lack of hyperbaric facilities (Meredith & Vale, 1988; Anand et al., 1988), and due to inadequate awareness on the part of hospital staff. We report a case of a patient deeply unconscious as a result of CO poisoning, in which serial treatments with HBO over a period of 14 days, produced dramatic results.

Adult↗
PubMed1976

Anaerobic growth of a Rhodopseudomonas species in the dark with carbon monoxide as sole carbon and energy substrate.

A species of Rhodopseudomonas that grows under strict anaerobic conditions in the dark and requires CO was isolated from lake and pond sediments. Although anaerobic growth in the dark occurs in a chemically defined mineral medium with CO as the only carbon and energy source, growth is stimulated by adding trypticase. Under these conditions, cells exhibit a generation time of 6.7 hr and reach a final concentration of 1 to 3 X 10(9) cells per ml of liquid medium. Resting suspensions of CO-grown cells metabolize about 6.7 mumol of CO per mg of protein in 1 hr and produce equimolar amounts of CO2 and H2 according to the equation CO + H2O leads to CO2 + H2. As predicted by this equation, when cells were suspended in tritium-labeled water containing potassium phosphate buffer at pH 7.0 and incubated with pure CO, 3H2 gas was produced at linear rate with a constant specific activity.

Anaerobiosis↗
PubMed1979

Pulmonary excretion of carbon monoxide in the human newborn infant as an index of bilirubin production: III. Measurement of pulmonary excretion of carbon monoxide after the first postnatal week in premature infants.

Using a single pass, flow-through system, the excretion rate of endogenously produced carbon monoxide (VeCO) was measured as an index of bilirubin production in 41 Caucasian infants of various gestational ages after the first postnatal week. twenty-one were less than or equal to 32 weeks gestation. The mean slope for the 25 premature infants with multiple VeCO determinations was -0.21 +/- 0.11 (SE) microliters/kg/hour per day (P less than .025, one-tailed). Fifteen premature infants with at least three VeCO determinations during the first 30 days of life had an average decrease in total CO excreted of 1.33% per day compared to the extrapolated initial value of total CO excretion of 27.0 +/- 2.0 (SE) microliters/hour, giving a calculated maximum red cell life span of 75 days.

Bilirubin↗
PubMed1975

Extraction of biologically active erythropoietin from kidneys of carbon monoxide intoxicated mice.

Carbon monoxide injected subcutaneously in mice produces a profound intoxication during a six hour-period. From 2 to 4 hr after the start of carbon monoxide (CO)-hypoxemia large amounts of erythropoietin (ESF) are released in the plasma. Renal extracts obtained at the same time showed higher specific activity than that found in the plasma extracts. No activity was recovered from liver and spleen extracts. Removal of the kidney abolishes totally the production of ESF.

Animals↗
PubMed1992

Occupational exposure to carbon monoxide and sulphur dioxide during the manufacture of carbon black.

The manufacture of carbon black is known to generate carbon monoxide and sulphur dioxide in the 'production gas' and the pyrolysis products of the 'production gas', respectively. Adverse health effects have been reported as associated with both contaminants (coronary heart disease with carbon monoxide and respiratory morbidity with sulphur dioxide). A major cross-sectional and longitudinal respiratory morbidity study is being conducted to assess the effects of exposure to carbon black on lung function, on chest X-rays and on responses to a questionnaire. The questionnaire includes questions on respiratory and cardiovascular symptoms, so that information regarding confounding exposure is essential. The working population of 18 manufacturing plants in seven European Countries was split into 13 job title numbers (1-13) which were then amalgamated into five job categories (A-E), with an appropriate (statistically) number of samples taken from each plant-job category. In total, 1322 carbon monoxide samples and 1301 sulphur dioxide samples were taken, using actively pumped longterm colorimetric tubes. In the majority of cases, more than half of the samples in each plant-job category were either zero or trace, thereby preventing the accurate estimation of the average exposure. The highest median carbon monoxide concentration was from the amalgamated data from all 18 plants in job number 9 (furnace operators), the highest median sulphur dioxide concentration was only 'trace'. The large number of zero and trace values also precluded the generation of current and retrospective exposure indices.

Air Pollutants, Occupational↗
PubMed1977

Placental diffusing capacities at varied carbon monoxide tensions.

To test the hypothesis that carbon monoxide transfer across the placenta is, in part, a facilitated process, we have looked for evidence of saturation kinetics for carbon monoxide. In eight pregnant ewes, fetal to maternal carbon monoxide transfer was examined in a preparation in which the fetal side of the placenta was perfused with blood. The carboxyhemoglobin concentrations on the fetal side of the placenta were varied from 4.8 to 70% in 23 measurements. At increased carbon monoxide tensions, the transfer from fetus to mother always decreased. The slope of log rate of carbon monoxide transfer vs. log partial pressure gradient across the placenta was significantly different from 1. Placental membrane diffusing capacity was calculated separately from total placental diffusing capacity which includes hemoglobin reaction rates and erythrocyte membrane diffusion. Placental membrane diffusing capacity decreased at increased carbon monoxide tensions. Placental permeability for urea did not change with increasing carbon monoxide tensions. These results are consistent with the hypothesis that carbon monoxide diffusion in the placenta is, in part, carrier mediated.

Animals↗
PubMed1977

End-expired air technic for determining occupational carbon monoxide exposure.

Fluctuating carbon monoxide (CO) levels in the ambient air and recent smoking can lower the accuracy of the end-expired air sampling technic in COHB estimation, which involves the calculation of a regression equation relating measured carboxyhemoglobin (COHb) levels to CO levels in end-expired air after breathholding. Data collected under both laboratory and field conditions using this technic are presented in this study to suggest that, for increased accuracy of COHb estimation, researches should allow volunteers who have just smoked or are working in an atmosphere of fluctuating ambient CO levels to breathe a low CO atmosphere (less than 10 ppm) for at least two minutes before sampling, preferably an atmosphere close in CO level to that in which originally the blood and breath samples were collected to establish the regression equation.

Carbon Monoxide↗