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Biomedical subjects

J Foulds

Publications and source records attributed to J Foulds.

At least 37 records · Page 2Linked to original sources
PubMed1998

New tools for the diagnosis of tuberculosis: the perspective of developing countries.

New diagnostics for tuberculosis are urgently needed to replace or facilitate acid-fast bacilli (AFB) microscopy for the identification of smear-positive cases, and to improve the diagnosis of AFB smear-negative cases. These need to be appropriate for use in low income countries. Tests to replace or facilitate AFB microscopy must offer improvements to this test, including increased sensitivity, speed, ease of use, and safety. Products to improve the identification of smear-negative cases should focus on the diagnosis of patients with paucibacillary pulmonary disease, including children and human immunodeficiency virus (HIV) infected persons, and those with extrapulmonary forms of tuberculosis.

Costs and Cost Analysis↗
PubMed1997

Mood and physiological effects of subcutaneous nicotine in smokers and never-smokers.

This study compared the effect of subcutaneous nicotine injections (2 x 0.3 mg and 2 x 0.6 mg) with saline on subjective and physiological measures in 18 never-smokers and 18 smokers (24-h nicotine deprived), under conditions of rest and cognitive testing. Prior to the injections the mood of the smokers had deteriorated to a level significantly below that of the never-smokers as a result of tobacco withdrawal. Cognitive tests caused reductions in calmness and increased alertness but there was no evidence of nicotine improving mood in either group under either condition. The 0.6 mg dose worsened mood in never-smokers and caused unpleasant symptoms (e.g. dizziness and arm pain) in both groups. Compared with smokers, never-smokers experienced stronger symptoms of nicotine toxicity and a greater reduction in alertness in response to the 0.6 mg dose, suggesting chronic tolerance to some nicotine effects in smokers. Nicotine produced similar increases in heart rate and decreases in finger pulse volume in both groups. Our results imply that if nicotine has a mood enhancing effect it occurs only after tolerance has been acquired to its primary adverse effects, and that its ability to reverse the mood deterioration caused by tobacco withdrawal is susceptible to situational factors such as our experimental conditions.

Adult↗
PubMed1996

Cognitive performance effects of subcutaneous nicotine in smokers and never-smokers.

In a double-blind placebo-controlled crossover study the effects of two doses of subcutaneous nicotine and saline were compared on a range of performance measures in 18 abstaining smokers and 18 never-smokers. Each subject received two injections (40 min apart) of saline, 0.3 mg nicotine, or 0.6 mg nicotine in a balanced order over three sessions. Performance was assessed before and after the injections on nine tests [news recall, Sternberg memory task, finger tapping, logical reasoning, rapid visual information processing (RVIP), long-term word recognition, digit recall, Stroop test, and critical flicker fusion threshold]. In the abstinent smokers, nicotine produced significantly faster correct responses on the logical reasoning test, more target hits, faster reaction times and improved sensitivity on the RVIP task, and more correct responses on word recognition. In never-smokers, nicotine produced faster reaction times on the RVIP and digit-recall tasks, although in the latter case this was at the expense of fewer correct responses. There were no significant differences between the two groups' responses to nicotine but smokers performed worse than never-smokers prior to injections, even controlling for background characteristics. These results are consistent with other recent research suggesting a primary effect of nicotine in enhancing cognitive performance.

Adult↗
PubMed1996

Strategies for smoking cessation.

Smoking cessation strategies should be geared to the target group's level of motivation to quit, and degree of tobacco addiction. Motivational interventions (e.g. media campaigns) aim to encourage more people to try to stop smoking. Treatment interventions (e.g. nicotine replacement) aim to increase the chances of a quit attempt being successful. In populations which have already been saturated by motivational interventions, the overall effect of adding further motivational interventions may be rather small, and possibly non-existent in heavy smokers. As a population's smoking prevalence declines, so the balance of interventions should shift from motivational to treatment approaches. Nicotine replacement is an effective smoking cessation aid and should form the basis for treating moderate to heavy smokers. There may be a case for the development of more specialist clinics to treat motivated but addicted smokers and train health professionals how to apply effective smoking cessation methods as part of their routine work.

Administration, Cutaneous↗
PubMed1996

Global eradication of poliomyelitis: benefit-cost analysis.

A benefit-cost analysis of the Poliomyelitis Eradication Initiative was undertaken to facilitate national and international decision-making with regard to financial support. The base case examined the net costs and benefits during the period 1986-2040; the model assumed differential costs for oral poliovirus vaccine (OPV) and vaccine delivery in industrialized and developing countries, and ignored all benefits aside from reductions in direct costs for treatment and rehabilitation. The model showed that the "break-even" point at which benefits exceeded costs was the year 2007, with a saving of US$ 13 600 million by the year 2040. Sensitivity analyses revealed only small differences in the break-even point and in the dollars saved, when compared with the base case, even with large variations in the target age group for vaccination, the proportion of case-patients seeking medical attention, and the cost of vaccine delivery. The technical feasibility of global eradication is supported by the availability of an easily administered, inexpensive vaccine (OPV), the epidemiological characteristics of poliomyelitis, and the successful experience in the Americas with elimination of wild poliovirus infection. This model demonstrates that the Poliomyelitis Eradication Initiative is economically justified.

Child, Preschool↗
PubMed1995

Counting the costs of children's smoking.

The recent publication of the 1994 OPCS survey of smoking among secondary school children confirmed that the Health of the Nation target for children's smoking (a reduction in regular smoking from 8% in 1988 to less than 6% in 1994) has not been achieved. In 1994, 12% of English schoolchildren aged 11-15 were regular smokers (as were 12% in Scotland, 9% in Wales, and 12.5% in Northern Ireland). In 1994 the government spent around 10 million pounds on initiatives to prevent smoking, but received around 8643 million pounds in tax receipts from tobacco sales, about 108 million pounds of which was tax receipts from the illegal sale of cigarettes to children under 16 years old. The tobacco industry spent an estimated 100 million pounds on promotional activities. Improving current trends in children's smoking by the year 2000 will require decisive action by the government. The government should legislate to ban tobacco advertising and should use the 108 million pounds taken each year in taxes from smoking children to fund smoking cessation and prevention initiatives.

Adolescent↗
PubMed1995

A case of nicotine psychosis?

A woman attempting to stop smoking using transdermal nicotine patches experienced a variety of transient delusions and hallucinations after smoking a cigarette. Various possible explanations are discussed.

Administration, Cutaneous↗
PubMed1995

The role of nicotine in tobacco smoking: implications for tobacco control policy.

This paper outlines some of the evidence that tobacco smoking is maintained by addiction to nicotine. Smokers often perceive that tobacco helps them cope with stress and aids their mental alertness. Nicotine withdrawal symptoms are one important factor preventing many smoker from quitting (only about 3% succeed with each unaided quit attempt). A number of policies are suggested to reduce the health consequences of smoking more quickly than at present. These include (a) banning all tobacco advertising and prosecuting retailers who sell illegally to children, in order to reduce the number of young people becoming addicted, (b) increasing the real price of tobacco in order to encourage more people to try to stop smoking, (c) providing specialist smokers' clinics in every large general hospital in order to assist highly motivated but addicted smokers to quit and (d) increasing the rate at which tobacco manufacturers must reduce permissible tar and carbon monoxide yields, such that in 20 years time only nicotine delivery products which are free of tar and carbon monoxide will be allowed.

Adolescent↗
PubMed1994

Effect of subcutaneous nicotine injections of EEG alpha frequency in non-smokers: a placebo-controlled pilot study.

The effect of two subcutaneous injections of 0.6 mg nicotine, administered 40 min apart, was compared with placebo in four non-smoking subjects in a counter-balanced double-blind crossover design. The nicotine injections produced mean peak plasma nicotine concentrations of 5.3 ng/ml 10 min after the first injection and 8.5 ng/ml 10 min after the second injection. The nicotine injections produced an increase in mean dominant alpha frequency on the electroencephalogram (EEG) which was 2 Hz greater than the effect of placebo (P = 0.049) and also produced a heart-rate boost which was 8 beats per minute greater than that produced by placebo (P = 0.022). These effects on dominant alpha frequency and heart rate were most apparent in the 10 min following each nicotine injection. The increase in dominant alpha frequency found in non-smokers in this study was similar to that following nicotine inhalation in abstinent smokers in previous studies, and suggests that this is a primary effect of nicotine, rather than simply a reversal of withdrawal-induced EEG slowing.

Adult↗
PubMed1993

Transdermal nicotine patches with low-intensity support to aid smoking cessation in outpatients in a general hospital. A placebo-controlled trial.

OBJECTIVE: To assess whether transdermal nicotine patches combined with low-intensity support can help outpatients in a general hospital stop smoking. DESIGN: Randomized, double-blind, placebo-controlled trial with 12 weeks of follow-up. SETTING: Department of Thoracic Medicine in an inner-city public general hospital, London, England. SUBJECTS: Two hundred forty-eight outpatients in a general hospital, who smoked at least 10 cigarettes per day (the majority were being treated for smoking-related diseases), referred by clinicians at the hospital. INTERVENTION: Brief advice to stop smoking and daily application of transdermal nicotine patches (delivering 15 mg over 16 hours) or placebo, with follow-up appointments at 1, 3, 6, and 12 weeks, with a doubling of the dosage for continuing smokers at week 1. MAIN OUTCOME MEASURE: Sustained abstinence from tobacco from week 3 to week 12 validated with measurement of expired-air carbon monoxide concentration at weeks 3, 6, and 12. RESULTS: Twenty-nine (23.4%) of 124 subjects assigned to the nicotine group were validated as having abstained from smoking at both weeks 3 and 6, compared with 16 (12.9%) of 124 subjects receiving placebo (P = .008). At week 12, 22 (17.7%) of the subjects in the nicotine group were validated as having abstained at all three points as were 15 (12.1%) of the subjects in the placebo group (P = .058). CONCLUSION: Transdermal nicotine patches combined with low-intensity support are effective in helping outpatients in a general hospital stop smoking but do not prevent relapse after 6 weeks.

Administration, Cutaneous↗
PubMed1993

Salicylate induction of antibiotic resistance in Escherichia coli: activation of the mar operon and a mar-independent pathway.

Since the growth of wild-type Escherichia coli in salicylate results in a multiple antibiotic resistance phenotype similar to that of constitutive mutants (Mar) of the chromosomal mar locus, the effect of salicylate on the expression of the marRAB operon was investigated. The amount of RNA hybridizing with a mar-specific DNA probe was 5 to 10 times higher in wild-type cells grown with sodium salicylate (5.0 mM) than in untreated controls. Untreated Mar mutants had three to five times more mar-specific RNA than wild-type cells did. When a Mar mutant was treated with salicylate, a 30- to 50-fold increase of mar-specific RNA was seen. In wild-type cells bearing a mar promoter-lacZ fusion on the chromosome, salicylate increased beta-galactosidase activity by sixfold. Thus, salicylate induces transcription of the marRAB operon. Other inducers of phenotypic multiple antibiotic resistance, e.g., benzoate, salicyl alcohol, and acetaminophen, but not acetate, also increased transcription from the mar promoter but to a lesser extent than did salicylate. Both in wild-type and mar-deficient strains, growth in salicylate resulted in increased antibiotic resistance, decreased permeation of the outer membrane to cephaloridine, increased micF transcription, and decreased amounts of OmpF. However, the magnitude of these changes was generally greater in wild-type (mar-containing) cells. Thus, salicylate and other compounds can induce transcription of the mar operon and, presumably, give rise to multiple antibiotic resistance via this pathway. However, salicylate can also activate an unidentified, mar-independent pathway(s) which engenders multiple antibiotic resistance.

Ampicillin↗
PubMed1992

Effect of transdermal nicotine patches on cigarette smoking: a double blind crossover study.

The effect of transdermal nicotine patches on ad libitum cigarette smoking was examined in 30 subjects by measuring behavioural, biochemical and subjective aspects of smoking during a week of smoking without patches, and then a week each of nicotine and placebo patches in a randomised double blind crossover design. While wearing nicotine patches the subjects did not reduce the number of cigarettes smoked, but their expired carbon monoxide was reduced by 14%, they obtained less satisfaction from their cigarettes, and reported fewer and weaker urges to smoke. Down-regulation of nicotine intake from cigarettes was imprecise, such that when subjects wore nicotine patches their post-cigarette plasma nicotine concentration increased to an average of 45 ng/ml compared with 37 ng/ml in both no patch and placebo patch conditions. As the nicotine patches produced a plasma nicotine concentration of 15.9 ng/ml in abstinent subjects, this suggests a 22% reduction in nicotine intake from cigarettes while wearing nicotine patches. No serious symptoms of nicotine overdose were reported. It is suggested that the continuous absorption of nicotine from the patch may cause a build-up of acute tolerance to both toxic and pleasant subjective effects from smoking.

Administration, Cutaneous↗
PubMed1992

Exposure to passive smoking among bar staff.

The median saliva cotinine concentration in 42 non-smoking bar staff in central London and Birmingham was 7.95 ng/ml, indicating a nicotine intake of about 0.6 mg per day. Pubs appear to give rise to exceptionally heavy exposure to environmental tobacco smoke. Passive smoking in pubs is of concern for its impact both on customers and on those for whom the pub is a place of work.

Adult↗