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M Knowles

Publications and source records attributed to M Knowles.

63 records · Page 4Linked to original sources

The contribution of epidemiology.

Epidemiologic studies directly contribute data on risk (or benefit) in humans as the investigated species, and in the full food intake range normally encountered by humans. This paper starts with introducing the epidemiologic approach, followed by a discussion of perceived differences between toxicological and epidemiologic risk assessment. Areas of contribution of epidemiology to the risk assessment process are identified, and ideas for tailoring epidemiologic studies to the risk assessment procedures are suggested, dealing with data collection, analyses and reporting of both existing and new epidemiologic studies. The dietary habits and subsequent disease occurrence of over three million people are currently under observation worldwide in cohort studies, offering great potential for use in risk assessment. The use of biomarkers and data on genetic susceptibility are discussed. The paper describes a scheme to classify epidemiologic studies for use in risk assessment, and deals with combining evidence from multiple studies. Using a matrix approach, the potential contribution to each of the steps in the risk assessment process is evaluated for categories of food substances. The contribution to risk assessment of specific food substances depends on the quality of the exposure information. Strengths and weaknesses are summarized. It is concluded that epidemiology can contribute significantly to hazard identification, hazard characterisation and exposure assessment.

Biomarkers↗

[Effects of transdermal nicotine as an adjunct in smoking cessation therapy. A double-blind randomized study controlled with placebo].

To assess the smoking cessation efficacy of transdermal nicotine patches an adjunct to low-intervention therapy, we conducted a double-blind, placebo-controlled trial in 158 smokers. Participants were randomly assigned to one of the following three study regimens that required daily application of two 15-cm2 patches: 1) 24-hour nicotine delivery, 2) nicotine delivery during wakeful hours only, and 3) placebo. The impact of the three regimens on smoking cessation rates and tobacco withdrawal symptoms was examined. During the last 2 weeks of the trial, 39% of the 24-hour nicotine regimen delivery group, 35% of those on wakeful hour nicotine regimens, and 13.5% of the placebo treatment group achieved abstinence. Self-reported quit rates for the two nicotine patch-wearing regimens, as compared with that for the placebo group, continued to be significantly higher at 6 months. Moreover, compared with placebo, the transdermal nicotine patches significantly reduced tobacco withdrawal symptoms during the first few weeks of quitting. The differences in quit rates and tobacco withdrawal symptoms between the to active groups were not statistically significant. The patches were well tolerated both topically and systemically. We concluded that transdermal nicotine, when used as an adjunct to low-intervention therapy, significantly reduced tobacco withdrawal symptoms and enhanced smoking cessation rates.

Administration, Cutaneous↗