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Biomedical subjects

M A Russell

Publications and source records attributed to M A Russell.

At least 145 records · Page 8Linked to original sources
PubMed1980

Relation of nicotine yield of cigarettes to blood nicotine concentrations in smokers.

Blood nicotine and carboxyhaemoglobin (COHb) concentrations were studied in 330 smokers (206 women and 124 men). Blood nicotine concentrations in individual smokers varied from 25 to 444 nmol/l (4 to 72 ng/ml). The average concentration, 203 nmol/l (33 ng/ml), was the same in the men and the women, although cigarette consumption was higher in the men. Despite large differences in nicotine yield, there was no relation between blood nicotine concentration and the type of cigarette smoked: smokers of plain, untipped cigarettes (1.9 mg nicotine), cigarettes with unventilated filters (1.3 mg nicotine), and cigarettes with ventilated filters (0.8 mg nicotine) had similar blood nicotine concentrations. Cigarette consumption was also similar in these three groups. The correlation between blood nicotine concentration and nicotine yield of cigarette, though significant, was low (0.21, p < 0.001), showing that the nicotine yield of the cigarettes accounted for only 4.4% of the variation in blood nicotine concentrations. Similarly, the low correlation of 0.30 between COHb concentration and cigarette consumption suggests that cigarette consumption accounted for only 9% of the variation in the amount of smoke taken into the smokers' lungs. These results suggest that the assumed health advantage of switching to lower-tar and lower-nicotine cigarettes may be largely offset by the tendency of smokers to compensate by increasing inhalation. The findings of epidemiological studies showing lower risks with filter-tipped cigarettes may be attributable to other factors such as biases in the samples and changes in the quality and carcinogenicity of tobacco tar, rather than to reduced tar intake.

Carboxyhemoglobin↗
PubMed1980

A new age for snuff?

Blood-nicotine levels were measured during non-inhaled cigar smoking and after taking snuff. The rate of nicotine absorption from non-inhaled cigar smoking was slow. This may explain why many cigarette smokers continue to inhale when they switch to cigars. In contrast, the rate of absorption from snuff was extremely rapid. Peak levels which matched those of cigarette smoking were reached within 5 min. Snuff could be an acceptable and less harmful substitute for cigarette smoking.

Humans↗
PubMed1980

Smokers' response to shortened cigarettes: dose reduction without dilution of tobacco smoke.

This study was designed to examine the response of smokers to shortening their usual brand of cigarettes. The shortening reduces the dose of smoke available from each cigarette without affecting concentration and therefore differs from dose reduction by dilution, which occurs when smokers switch to cigarettes with lower tar and nicotine deliveries. Measures of smoking behavior (e.g., cigarette consumption, puff rate), mouth-level nicotine intake (calculated from butt content), and intake to the lungs (plasma nicotine and COHb) were made in 10 smokers after 48 hr ad libitum smoking of full, three-quarter, and half-length cigarettes in a Latin square design. Mouth-level smoke intake was maintained on shortened cigarettes due to a combination of 2 types of compensatory maneuver: (1) by increasing the intensity of puffing and thereby extracting proportionately more of the smoke available from each cigarette and (2) by smoking more cigarettes. The amount of smoke inhaled, on the other hand, was only partially maintained (58% compensation). This was achieved by increase in cigarette consumption alone. There was achieved by increase in cigarette consumption alone. There was no evidence of any compensatory increase in the amount of smoke inhaled from each cigarette. Increase in consumption was thus the only maneuver that contributed to maintaining smoke intake at lung level; mouth-level intake was regulated by increasing intake per cigarette as well as consumption.

Adult↗
PubMed1980

Assay of nicotine in biological materials: sources of contamination and their elimination.

A previous method for the measurement of nicotine in biological samples was subject to occasional interference from a contaminant which eluted simultaneously with the internal standard (quinoline). This has been rectified by substituting isoquinoline as the internal standard and modifying the operating conditions of gas chromatography. Other source of contamination in nicotine assays such as the analytical reagents, the atmosphere and the sample itself are discussed in detail.

Chromatography, Gas↗
PubMed1979

Effect of general practitioners' advice against smoking.

During four weeks all 2138 cigarette smokers attending the surgeries of 28 general practitioners (GPs) in five group practices in London were allocated to one of four groups: group 1 comprised non-intervention controls; group 2 comprised questionnaire-only controls; group 3 were advised by their GP to stop smoking; and group 4 were advised to stop smoking, given a leaflet to help them, and warned that they would be followed-up. Adequate data for follow-up were obtained from 1884 patients (88%) at one month and 1567 (73%) at one year. Changes in motivation and intention to stop smoking were evident immediately after advice was given. Of the people who stopped smoking, most did so because of the advice. This was achieved by motivating more people to try to stop smoking rather than increasing the success rate among those who did try. The effect was strongest during the first month but still evident over the next three months and was enhanced by the leaflet and warning about follow-up. An additional effect over the longer term was a lower relapse rate among those who stopped, but this was not enhanced by the leaflet and warning about follow-up. The proportions who stopped smoking during the first month and were still not smoking one year later were 0.3%, 1.6%, 3.3%, and 5.1% in the four groups respectively (P <0.001).The results suggest that any GP who adopts this simple routine could expect about 25 long-term successes yearly. If all GPs in the UK participated the yield would exceed half a million ex-smokers a year. This target could not be matched by increasing the present 50 or so special withdrawal clinics to 10 000.

Adolescent↗
PubMed1979

Improved gas chromatographic method and micro-extraction technique for the measurement of nicotine in biological fluids.

A rapid and sensitive method for the measurement of nicotine in plasma, urine, saliva and breast milk is described. An internal standard (quinoline) is added to the samples and these are made alkaline and extracted with diethyl ether. The solvent is evaporated to small bulk and extracted with dilute acid which is then made alkaline. The nicotine is finally extracted into butyl acetate and an aliquot of this extract is injected onto a gas-chromatograph fitted with a nitrogen detector. Quantitation relies on comparison of peak areas and the calibration curve is linear over the concentration range 0.5 to 100 ng ml-1. Nicotine concentrations as low as 0.1 ng ml-1 can be measured. In addition, a micro-method is described which requires only 100 microliter of sample and yields an accurate result in 5 min.

Chromatography, Gas↗
PubMed1978

The BSRI M, F, and androgyny scores are bipolar.

Demonstrates that the Bem Sex-Role Inventory (BSRI) masculinity (M), femininity (F), and Androgyny scores reflect a bipolar dimension rather than two independent dimensions and their unique derivative. The mean endorsement of the BSRI M and F items was calculated for 50 males and 50 females separately and as a combined group. The BSRI M and F items then were scored in a bipolar fashion. A total Bipolar Androgyny score was calculated for each S by summing the S's Bipolar Androgyny scores on the M and F items. The data indicated that (1) Bem's M scores and the derived Bipolar Androgyny scores based on Bem's M items were highly correlated (congruent to .90); (2) Bem's F scores and the Bipolar Androgyny scores based on Bem's F items were highly correlated (congruent to .90); and (3) Bem's Androgyny scores and the total Bipolar Androgyny scores were highly correlated (congruent to .90). These results indicate that the BSRI Androgyny score reflects a bipolar dimension.

Adolescent↗
PubMed1978

Further evidence that M-F is bipolar and multidimensional.

Conducted a study to identify a set of cognitive skills tests on which there are significant sex differences. The main study determined the comparability of several bipolar M-F scales and the relations between the full range of scores on each of those bipolar M-F scales and self-rated sexual orientation; 110 females and 113 males completed six cognitive tests, the Bem Sex Role Inventory (BSRI), the Minnesota Multiphasic Personality Inventory (MMPI) and the Kinsey Sexual Orientation scale (KSO). Correlations in the combined-sex group were substantially higher than in either of the single-sex groups. Each of the several M-F measures was related significantly to sexual orientation in the combined-sex group, and the combination of the MMPI Mf scale and the Bem Androgyny Score accounted for a small but significantly greater portion of the variance in self-rated sexual orientation than did the MMPI Mf scale alone. The data support the view that M-F may be considered to be a bipolar and probably multidimensional variable.

Adolescent↗
PubMed1978

Adjustment of smokers to dilution of tobacco smoke by ventilated cigarette holders.

This study was designed to examine the extent to which smokers would compensate for the dilution of smoke produced by ventilated cigarette holders. Peak plasma nicotine and carboxyhemoglobin levels were measured in 18 smokers when they had been smoking normally and when they had been using holders which dilute the smoke by about 20% (holder 1) and 60% (holder 2) for periods of 2 days and 7 days. Comparison of the observed blood levels with the "expected" levels estimated from the dilution factors of the holders showed that subjects partially compensated on holder 2 but showed little or no compensation on holder 1. There were no changes in the number of cigarettes smoked when using the holders so any compensation achieved must have been due to increasing the intake from each cigarette. There was wide individual variation in the amount of compensation with about 50% of subjects compensating fairly consistently on both holders. Degree of compensation was not significantly associated with usual cigarette consumption, plasma nicotine and carboxyhemoglobin levels when smoking without a holder, the nicotine yields of the subjects' cigarettes, or the experience of withdrawal symptoms and the degree of satisfaction when using the holders. It cannot be determined from this study whether the compensation observed was mediated by a need to regulate the intake of nicotine rather than some other factor.

Adult↗