Search PubMed⌕ Search

Biomedical subjects

H Ashton

Publications and source records attributed to H Ashton.

At least 37 records · Page 2Linked to original sources
PubMed1984

Effects of acupuncture and transcutaneous electrical nerve stimulation on cold-induced pain in normal subjects.

The effects of acupuncture, transcutaneous electrical nerve stimulation (TENS) at high (100 Hz) and low (8 Hz) frequency and placebo on pain induced by cold immersion of the hand were studied in 46 young healthy male and female volunteers. Acupuncture produced significant elevations of pain threshold, while 100 Hz TENS or placebo had no effect. Eight Hertz TENS produced elevation of pain threshold with significant variation in response between individuals. There was some evidence that the L scale score of the Eysenck Personality Questionnaire predicted analgesic outcome for 8 Hz TENS. No significant relationship was found between baseline pain threshold or tolerance and personality variables.

Acupuncture Therapy↗
PubMed1981

Should intake of carbon monoxide be used as a guide to intake of other smoke constituents?

The relation between blood carboxyhaemoglobin (COHb) and plasma nicotine concentrations was studied in a group of 12 smokers smoking cigarettes of three levels of standard delivery. While the intake of carbon monoxide from a single cigarette was unrelated to the intake of nicotine, presmoking "trough" concentrations of the two substances (reflecting longer-term exposure) were highly correlated. Various other measures of nicotine exposure were at best only moderately correlated with blood nicotine concentrations. Thus trough COHb concentrations might be used to provide a reliable indication of the exposure to nicotine of individual smokers smoking the same type of cigarette, and of the relative exposure to nicotine of populations smoking cigarettes of different standard deliveries.

Carbon Monoxide↗
PubMed1981

The seed and the soil: effect of dosage, personality and starting state on the response to delta 9 tetrahydrocannabinol in man.

1 The effects of two doses of delta 9THC (2.5 and 10 mg), delivered by paced smoking of herbal cigarettes, on CNV magnitude, subjective mood ratings and heart rate were studied in 20 subjects. 2 There were highly significant interactions between drug dosage and Extraversion and Neuroticism scores, so that the direction and degree of response to the different doses of delta 9THC depended on the personality characteristics of the subjects. 3 The effects of 9 mg delta 9THC and placebo, delivered in herbal cigarettes smoked naturally, on smoking behaviour, subjective mood ratings, measures of autonomic activity and auditory and visual cortical evoked responses were compared in 12 subjects. 4 Smoking behaviour, subjective 'high' rating and elevation of heart rates were the most significant discriminators between drug and placebo. The latency of some of the components of the visual evoked responses was also increased by delta 9THC. 5 There was a significant correlation between the effects of delta 9THC on skin conductance reactivity and the basal (pre-drug) level, reactivity increasing after drug in subjects with low basal reactivity and decreasing in those with high basal levels. 6 Both experiments provided clear evidence of dose-dependent biphasic stimulant and depressant actions of delta 9THC on both subjective and objective measures, and these effects were influenced by the personality and the starting state of the subjects.

Cannabis↗
PubMed1979

Self-titration by cigarette smokers.

An 11-week crossover study was carried out in which 12 subjects smoked high-nicotine (1.84 mg standard yield) and low-nicotine (0.6 mg) cigarettes after an initial period of smoking their usual brands with a medium-nicotine yield (mean 1.4 mg). Plasma and urine nicotine concentrations, carboxyhaemoglobin (COHb) concentration, puffing behaviour, 24-hour cigarette consumption, and butt nicotine content were measured. The changes in plasma nicotine and blood COHb concentrations showed that the smokers compensated for about two-thirds of the difference in standard yields when switched to either high- or low-nicotine cigarettes. Thus, compared with the medium-nicotine brand, the intake of nicotine and carbon monoxide was only about 10% higher when subjects smoked the high-nicotine cigarettes, which had a standard yield 30-40% higher than the medium brands; and only about 15% lower when they smoked the low-nicotine cigarettes, which had a standard yield about 50% lower than the medium brands. But nicotine content and urine nicotine concentrations followed a similar pattern. Changes in puffing behaviour and in 24-hour cigarette consumption were only slight.The results show clear evidence of both upward and downward self-titration of nicotine and carbon monoxide (and tar) intakes when smokers change to cigarettes with standard yields that differ over the range studied.

Adult↗
PubMed1978

A comparison of some physiological and psychological effects of Motival (fluphenazine and nortriptyline) and diazepam in normal subjects.

1 The effects in normal subjects of a single oral dose of Motival (one tablet, containing fluphenazine 0.5 mg and nortriptyline 10 mg) on the contingent negative variation (CNV), reaction time, heart rate, blood pressure and self-rating scales for alertness, anxiety, tension, detachment and depression were compared with those of diazepam (5 mg and 7.5 mg) and placebo or propranolol (60 mg). 2 After diazepam (5 mg: twelve subjects and 7.5 mg: seven subjects) there was a significant decrease in CNV magnitude while after Motival (twelve subjects) there was no significant alteration in CNV magnitude compared to placebo. 3 After diazepam (7.5 mg: seven subjects) there was also a fall in subjective ratings for alertness and tension; this fall was significantly greater than the changes after Motival which did not reduce subjective ratings for alterness or tension below "average" levels. Anxiety ratings did not differ significantly between the two drugs. Changes after propranolol were intermediate in all scales. 4 It is concluded that under these conditions diazepam caused central nervous system depression while Motival did not.

Blood Pressure↗
PubMed1975

Cigarette smoking in pregnancy: differences in peripheral circulation between smokers and non-smokers.

Ten smokers and ten non-smokers were followed serially from 12 to 16 weeks of pregnancy to six weeks postnatally. Measurements of calf and foot blood flow and toe and finger skin temperature were made at 4 to 6 week intervals in both groups, and the acute effects on the peripheral circulation of smoking one standard cigarette were also measured in the smokers at each stage of pregnancy. Comparison between the smokers and non-smokers showed that in the last trimester of pregnancy smokers had significantly higher foot blood flow and toe and finger temperature than non-smokers. These circulatory variables rose during the period of pregnancy studied in smokers but altered little in non-smokers. There was no significant difference in calf blood flow between the groups. Smoking a cigarette during pregnancy caused a fall in foot blood flow and in finger and toe skin temperature. Smoking increased calf blood flow between 12 and 25 weeks of pregnancy but decreased it in late pregnancy. Previous investigations of blood flow in pregnancy have not differentiated between smokers and non-smokers. It is suggested that the rise in foot blood flow and skin temperature believed to occur generally during pregnancy applies mainly to smokers. Some possible reason for differences in skin blood flow between smokers and non-smokers in pregnancy are discussed.

Adult↗
PubMed1973

Stimulant and depressant effects of cigarette smoking on brain activity in man.

Cigarette smoking was found to alter the E.E.G. negativity associated with attention: the 'contingent negative variation' was increased in some smokers and decreased in others. This finding is consistent with the known dual action of nicotine to stimulate or depress neural activity and suggests a means of investigating the effects of other centrally-acting drugs on the human brain.

Contingent Negative Variation↗