SciCombinator

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Concept: Nicotine

448

Electronic cigarettes (e-cigarettes) are generally recognized as a safer alternative to combusted tobacco products, but there are conflicting claims about the degree to which these products warrant concern for the health of the vapers (e-cigarette users). This paper reviews available data on chemistry of aerosols and liquids of electronic cigarettes and compares modeled exposure of vapers with occupational safety standards.

Concepts: Medicine, Smoking, Tobacco, Cigarette, Nicotine, Electronic cigarette, Propylene glycol, Cigarettes

344

The disease risks from cigarette smoking increased in the United States over most of the 20th century, first among male smokers and later among female smokers. Whether these risks have continued to increase during the past 20 years is unclear.

Concepts: United States, Smoking, Tobacco, Cigarette, Nicotine, Poverty in the United States, U.S. state, 20th century

340

Although the association between psychotic illness and cigarette smoking is well known, the reasons are unclear why people with psychosis are more likely to smoke than are the general population. We aimed to test several hypotheses. First, that daily tobacco use is associated with an increased risk of psychotic illness in both case-control and prospective studies. Second, that smoking is associated with an earlier age at onset of psychotic illness. Finally, that an earlier age at initiation of smoking is associated with an increased risk of psychosis. We also aimed to derive an estimate of the prevalence of smoking in patients presenting with their first episode of psychosis.

Concepts: Epidemiology, Smoking, Tobacco, Tobacco smoking, Cigarette, Nicotine, Cigar, Electronic cigarette

331

Background The Food and Drug Administration can set standards that reduce the nicotine content of cigarettes. Methods We conducted a double-blind, parallel, randomized clinical trial between June 2013 and July 2014 at 10 sites. Eligibility criteria included an age of 18 years or older, smoking of five or more cigarettes per day, and no current interest in quitting smoking. Participants were randomly assigned to smoke for 6 weeks either their usual brand of cigarettes or one of six types of investigational cigarettes, provided free. The investigational cigarettes had nicotine content ranging from 15.8 mg per gram of tobacco (typical of commercial brands) to 0.4 mg per gram. The primary outcome was the number of cigarettes smoked per day during week 6. Results A total of 840 participants underwent randomization, and 780 completed the 6-week study. During week 6, the average number of cigarettes smoked per day was lower for participants randomly assigned to cigarettes containing 2.4, 1.3, or 0.4 mg of nicotine per gram of tobacco (16.5, 16.3, and 14.9 cigarettes, respectively) than for participants randomly assigned to their usual brand or to cigarettes containing 15.8 mg per gram (22.2 and 21.3 cigarettes, respectively; P<0.001). Participants assigned to cigarettes with 5.2 mg per gram smoked an average of 20.8 cigarettes per day, which did not differ significantly from the average number among those who smoked control cigarettes. Cigarettes with lower nicotine content, as compared with control cigarettes, reduced exposure to and dependence on nicotine, as well as craving during abstinence from smoking, without significantly increasing the expired carbon monoxide level or total puff volume, suggesting minimal compensation. Adverse events were generally mild and similar among groups. Conclusions In this 6-week study, reduced-nicotine cigarettes versus standard-nicotine cigarettes reduced nicotine exposure and dependence and the number of cigarettes smoked. (Funded by the National Institute on Drug Abuse and the Food and Drug Administration Center for Tobacco Products; ClinicalTrials.gov number, NCT01681875 .).

Concepts: Clinical trial, Smoking, Tobacco, Tobacco smoking, Cigarette, Nicotine, Drug addiction, Addiction

219

 To estimate how far changes in the prevalence of electronic cigarette (e-cigarette) use in England have been associated with changes in quit success, quit attempts, and use of licensed medication and behavioural support in quit attempts.

Concepts: Statistics, Smoking, Tobacco, Cigarette, Nicotine, Smoking cessation, Electronic cigarette, Time series

219

Nicotine cigarette smoke is a large public health burden worldwide, contributing to various types of disease. Anti-tobacco media campaigns and control programs have significantly reduced smoking in the United States, yet trends for menthol cigarette smoking have not been as promising. Menthol cigarette smoking is particularly prevalent among young adults and African Americans, with implications for long-term impacts on health care. Continuing high rates of menthol cigarette addiction call into question the role of menthol in nicotine addiction. To date, a biological basis for the high rate of addiction and relapse among menthol cigarette smokers has not been defined. Studies have demonstrated a role for menthol in the metabolism of nicotine in the body. More recent findings now reveal an interaction between menthol and the nicotinic acetylcholine (nACh) receptor in cells. This receptor is central to the actions of nicotine in the brain, and plays an important role in nicotine addiction. The newly discovered effect of menthol on nACh receptors may begin to explain the unique addictive properties of menthol cigarettes.

Concepts: Smoking, Tobacco smoking, Cigarette, Nicotine, Addiction, Acetylcholine, Muscarinic acetylcholine receptor, Nicotinic acetylcholine receptor

202

Habitual chewing of “betel nut” preparations constitutes the fourth most common human self-administration of a psychoactive substance after alcohol, caffeine, and nicotine. The primary active ingredient in these preparations is arecoline, which comes from the areca nut, the key component of all such preparations. Arecoline is known to be a relatively non-selective muscarinic partial agonist, accounting for many of the overt peripheral and central nervous system effects, but not likely to account for the addictive properties of the drug. We report that arecoline has activity on select nicotinic acetylcholine receptor (nAChR) subtypes, including the two classes of nAChR most related to the addictive properties of nicotine: receptors containing α4 and β2 subunits and those which also contain α6 and β3 subunits. Arecoline is a partial agonist with about 6-10% efficacy for the α4* and α6* receptors expressed in Xenopus oocytes. Additionally, arecoline is a silent agonist of α7 nAChR; while it does not activate α7 receptors when applied alone, it produces substantial activation when co-applied with the positive allosteric modulator PNU-120696. Some α7 silent agonists are effective inhibitors of inflammation, which might account for anti-inflammatory effects of arecoline. Arecoline’s activity on nAChR associated with addiction may account for the habitual use of areca nut preparations in spite of the well-documented risk to personal health associated with oral diseases and cancer. The common link between betel and tobacco suggests that partial agonist therapies with cytisine or the related compound varenicline may also be used to aid betel cessation attempts.

Concepts: Nicotine, Acetylcholine, Muscarinic acetylcholine receptor, Nicotinic acetylcholine receptor, Acetylcholine receptor, Ibogaine, Cytisine, Areca nut

200

Tobacco use is the leading cause of preventable disease and death in the United States; if current smoking rates continue, 5.6 million Americans aged <18 years who are alive today are projected to die prematurely from smoking-related disease (1). Tobacco use and addiction mostly begin during youth and young adulthood (1,2). CDC and the Food and Drug Administration (FDA) analyzed data from the 2011-2015 National Youth Tobacco Surveys (NYTS) to determine the prevalence and trends of current (past 30-day) use of seven tobacco product types (cigarettes, cigars, smokeless tobacco, electronic cigarettes [e-cigarettes], hookahs [water pipes used to smoke tobacco], pipe tobacco, and bidis [small imported cigarettes wrapped in a tendu leaf]) among U.S. middle (grades 6-8) and high (grades 9-12) school students. In 2015, e-cigarettes were the most commonly used tobacco product among middle (5.3%) and high (16.0%) school students. During 2011-2015, significant increases in current use of e-cigarettes and hookahs occurred among middle and high school students, whereas current use of conventional tobacco products, such as cigarettes and cigars decreased, resulting in no change in overall tobacco product use. During 2014-2015, current use of e-cigarettes increased among middle school students, whereas current use of hookahs decreased among high school students; in contrast, no change was observed in use of hookahs among middle school students, use of e-cigarettes among high school students, or use of cigarettes, cigars, smokeless tobacco, pipe tobacco, or bidis among middle and high school students. In 2015, an estimated 4.7 million middle and high school students were current tobacco product users, and, therefore, continue to be exposed to harmful tobacco product constituents, including nicotine. Nicotine exposure during adolescence, a critical period for brain development, can cause addiction, might harm brain development, and could lead to sustained tobacco product use among youths (1,3). Comprehensive and sustained strategies are warranted to prevent and reduce the use of all tobacco products among U.S. youths.

Concepts: Smoking, Tobacco, Cigarette, Nicotine, Middle school, High school, Electronic cigarette, Youth

194

Nicotine is known as the drug that is responsible for the addicted behaviour of tobacco users, but it has poor reinforcing effects when administered alone. Tobacco product design features enhance abuse liability by (A) optimising the dynamic delivery of nicotine to central nervous system receptors, and affecting smokers' withdrawal symptoms, mood and behaviour; and (B) effecting conditioned learning, through sensory cues, including aroma, touch and visual stimulation, to create perceptions of pending nicotine reward. This study examines the use of additives called ‘pyrazines’, which may enhance abuse potential, their introduction in ‘lights’ and subsequently in the highly market successful Marlboro Lights (Gold) cigarettes and eventually many major brands.

Concepts: Central nervous system, Nervous system, Tobacco, Cigarette, Nicotine, Drug addiction, Addiction, Withdrawal

192

The number of quit attempts it takes a smoker to quit successfully is a commonly reported figure among smoking cessation programmes, but previous estimates have been based on lifetime recall in cross-sectional samples of successful quitters only. The purpose of this study is to improve the estimate of number of quit attempts prior to quitting successfully.

Concepts: Mathematics, Smoking, Nicotine, Smoking cessation, Estimation, Quitting