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Biomedical subjects

M A Russell

Publications and source records attributed to M A Russell.

At least 163 records · Page 9Linked to original sources
PubMed1977

Nicotine chewing gum as a substitute for smoking.

The capacity of nicotine-containing chewing gum to produce plasma nicotine levels comparable to heavy cigarette smoking was tested in 21 subjects. On a fixed schedule of one piece of gum (4 mg nicotine) per hour, the average peak plasma nicotine concentration was 175-7 nmol/l (28-5 ng/ml) compared to 189-3 nmol/l (30-7 ng/ml) obtained from normal ad libitum smoking. Unpleasant side effects were common and in some cases plasma nicotine concentrations were two and even three times as high as with smoking; The chewing gum provided some satisfaction to all but four subjects, but its degree was not related to the concentration of plasma nicotine it produced, neither was there an inverse relation between the plasma nicotine concentration while taking the gum and the subjective sense of missing cigarettesmthis suggests that the capacity of the gum to act as a substitute for smoking is not necessarily related to its capacity to provide nicotine. Flexible dosage dictated by individual needs would probably lower the incidence of side effects and might secure closer approximation to smoking concentrations of plasma nicotine.

Adult↗
PubMed1977

Is nicotine important to tobacco smoking?

Tobacco smoking is generally regarded as a form of nicotine dependence, but the evidence for this is slender. Two experiments are described here which examine the hypothesis that habitual smokers need nicotine and that they regulate their intakes of this drug. A laboratory test for smoking was devised which permitted the continuous monitoring of puffing as well as of selected physiologic variables; the procedure was also designed to reduce the influence of smoking habits and rituals. In the first experiment, inhaled amounts of tobacco smoke reduced subsequent ad libitum smoking in a dose-related way. In the second experiment comparable doses of nicotine were given intravenously to the same subjects, but they failed to affect ongoing smoking. However, both the inhaled and intravenous doses of the drug produced very similar physiologic effects. These experiments do not, therefore, support the nicotine-dependence hypothesis; thus the ways, if any, in which this drug sustains the tobacco-smoking habit merit further examination.

Adult↗
PubMed1977

Sudden infant death due to congenital adrenal hypoplasia.

Adrenocortical hypoplasia was found to be the cause of sudden death in a 9-month-old infant. Most sudden infant deaths in the first year of life are related to the sudden infant death syndrome, in which no specific pathologic changes are found at autopsy. Although specific causes for sudden death in infancy are well documented, adrenocortical hypoplasia is not a well-recognized cause of sudden infant death.

Adrenal Glands↗
PubMed1976

Effect of nicotine chewing gum on smoking behaviour and as an aid to cigarette withdrawal.

In a double-blind, placebo-controlled, crossover trial the effect of 2-mg nicotine chewing gum was studied in 43 smokers when they were smoking as inclined and when they were trying to stop smoking. Although 70% of the smokers stopped smoking during treatment, only 23% were still abstinent after one year. The effect of the nicotine, though significant, was small compared with the overall reduction in smoking. When the subjects were smoking as inclined cigarette consumption was reduced by an average of 37% on the nicotine gum compared with 31% on placebo gum, while avergage carboxyhaemoglobin (COHb) levels were reduced by 26% and 15% on the active and placebo gums respectively. When subjects tried to stop smoking there was a further considerable reduction in cigarette consumption, but no longer any difference between the two gums. Nevertheless, average COHb was still lower on the active gum. Plasma nicotine levels on the nicotine gum averaged only 10-7 ng/ml compared with 27-4 ng/ml after smoking. Better results could be expected with 4-mg nicotine gums.

Adult↗
PubMed1976

Low-tar medium-nicotine cigarettes: a new approach to safer smoking.

The logic of expecting people who cannot stop smoking to switch to cigarettes that have hardly any nicotine is questionable. Tar and nicotine yields of cigarettes available in Britain today correlate 0-93, and further reduction of tar intake is limited by the reluctance of smokers to tolerate similar reductions in nicotine. A new approach would be to aim at lowering tar yields of cigarettes from the present average of 18 mg to around 6 mg but maintaining nicotine yields at around 1-0 to 1-2 mg, which would be acceptable to most smokers. This approach requires that emphasis be placed on tar: nicotine ratios as well as on the absolute yields. These ratios for brands on sale in Britain today average 14-2 and range from 9-6 to 20-8. They provide an additional guide for comparing the relative harmfulness of different brands. For example, 35% of cigarette smokers in Britain smoke either Embassy Filter or Players No 6 Filter; by changing to John Player Carlton King Size they could reduce their tar intake by more than 20% without having to suffer any nicotine deprivation.

Humans↗
PubMed1976

Plasma nicotine levels after cigarette smoking and chewing nicotine gum.

Plasma nicotine levels were measured over seven hours of smoking cigarettes (1-2 mg nicotine) in a single subject under standardised conditions, and were compared with the levels obtained from chewing-gum containing either 2 mg or 4 mg nicotine. Levels comparable to those resulting from smoking were not obtained with the 2-mg gum, but peak levels on the 4-mg gum averaged 40-1 ng/ml from the third gum onwards compared with 49-2ng/ml after cigarettes. Nicotine was absorbed much more slowly from the gum than from cigarettes. It took 15-30 minutes for the 4-mg gum to raise the plasma nicotine by an average of 11-9 ng/ml compared with an average increase of 27-8 ng/ml within two minutes of completing each cigarette. In a sample of 15 smokers attending a withdrawal clinic the average plasma nicotine concentration while taking 2-mg nicotine chewing-gum was only 10-8 ng/ml compared with 30-4 ng/ml two minutes after smoking a cigarette. Although plasma nicotine levels equivalent to those following cigarette smoking may be obtained by chewing at least 10 pieces of 4-mg nicotine gum daily, the slower rate of absorption may limit its therapeutic value as a substitute for cigarette smoking.

Absorption↗
PubMed1975

Carbon monoxide yields of cigarettes and their relation to nicotine yield and type of filter.

Carbon monoxide (CO) yields of 11 popular brands of British cigarette, two types of cigarette containing tobacco-substitute, and one brand of cigar were measured under standardized conditions. Yields of the conventional cigarettes ranged from 5.0 to 20.2 mg per cigarette (1.3 to 4.7% by volume). The cigar yielded 81.7 mg (10.0%) CO and the two semi-synthetic cigarettes 17.2 (4.2%) and 28.2 mg (6.2%) CO. Puff-by-puff analysis showed an increase in CO concentration as a cigarette is smoked. In brands with nicotine yields over 1.0 mg no relationship was apparent between nicotine yield and CO yield, and the filters of cigarettes in this category did not appear to reduce the CO yield. In the low nicotine cigarettes with ventilated filters there appeared to be some correlation between nicotine yield and CO yield, and these filters were highly effective in reducing CO yield, owing mainly to the ventilation. We suggest that official publication of CO yields might motivate manufacturers to produce cigarettes with lower yields.

Carbon Monoxide↗
PubMed1975

Plasma nicotine levels after smoking cigarettes with high, medium, and low nicotine yields.

Plasma nicotine three minutes after smoking a cigarette was measured in 10 sedentary workers in mid-morning and five hours later on four typical working days. The average mid-morning level after they had been smoking their usual cigarettes (mean nicotine yield 1-34 ng) was 150-4 nmol/l (24-4 ng/ml) (range 95-6-236-7 nmol/l (15-5-38-4 ng/ml)). Despite great variation between smokersthe mid-morning levels of each smoker were fairly consistent over the four mornings and correlated 0-82 with their carboxyhaemoglobin levels. After continuing to smoke their usual brand or switching to a high-nicotine brand (3-2 mg) average afternoon levels of 185-6 and 180-0 nmol/6 (30-1 and 29-2 ng/ml) respectively were not significantly higher than the morning levels, but after switching to low-nicotine cigarettes (0-14 mg) the plasma nicotine dropped to an average of 52-4 nmol/l (8-5 ng/ml). The changes between morning and afternoon while smoking usual or high-nicotine cigarettes showed marked individual variation. The findings suggest that the plasma nicotine level just after a cigarette depends more on the way the cigarette is smoked than on its nicotine yield or the number which have been smoked over the preceding few hours.

Adult↗
PubMed1975

Blood and Urinary nicotine in non-smokers.

Of 39 urban non-smokers about half had measurable quantities of nicotine in their plasma (range 0 to 5times5 ng. per ml.) and almost all had nicotine in their urine during the early afternoon. The average concentration of urinary nicotine in non-smokers under natural conditions was 10times7 ng. per ml., but after deliberate exposure to tobacco smoke (mean duration seventy-eight minutes) in an unventilated room (38 p.p.m. of carbon monoxide) the average urinary nicotine level (80 ng. per ml.) was significantly higher than in non-smokers who had not been deliberately exposed to smoke (P less than 0times 001). Under natural conditions there was no overlap between the urine levels of non-smokers and the far higher levels of 18 smokers (mean 1236 ng. per ml.), suggesting that urinary nicotine may provide a more accurate assessment of an individual's smoking-status than blood-carboxyhaemoglobin. It is concluded that, as a result of passive smoking, most urban non-smokers have measurable amounts of nicotine in their bodyfluids for most of their lives.

Air Pollution↗
PubMed1975

Prognostic features of thyroid cancer. A long-term followup of 68 cases.

Sixty-eight cases of thyroid cancer were followed for 10 to 38 years after diagnosis. A minimum followup period of 10 years was necessary because of the long natural history of low-grade thyroid carcinoma. The prognosis of the disease was evaluated with regard to several parameters: age, sex, histologic appearance of the tumor, extent of disease, and treatment. The best prognosis was found in women less than 40 years of age with papillary carcinoma in whom there was neither extrathyroid extension nor metastasis and who were treated by surgery alone. Extrathyroidal cancer in the neck treated by radical neck dissection had a 100% survival rate at 15 years postdiagnosis. The poorest prognosis was in male patients over 60 years of age with metastatic undifferentiated carcinoma.

Adenocarcinoma↗