Effect of high-dose nicotine patch therapy on tobacco withdrawal symptoms among smokeless tobacco users.

No pharmacotherapies have been shown to increase long-term (> or = 6-month) abstinence rates among smokeless tobacco (ST) users. Available evidence suggests that underdosing may occur with standard-dose nicotine replacement therapy (NRT) in ST users. We investigated the effect of high-dose nicotine therapy on tobacco withdrawal symptoms among ST users in a randomized, controlled clinical pilot study. A total of 42 ST users using at least 3 cans or pouches per week were randomized to nicotine patch doses of 63, 42, or 21 mg/day or placebo for 8 weeks. Multiple daily assessments of tobacco withdrawal and nicotine toxicity were obtained with an electronic diary. During the first week of nicotine patch therapy, we observed a dose-response relationship such that higher nicotine patch doses were associated with less decreased arousal (chi2 = 6.87, p = .009), less negative affect (chi2 = 3.85, p = .05), and less restlessness (chi2 = 3.90, p = .048). During the second week, higher nicotine patch doses were associated with less decreased arousal (chi2 = 6.77, p = .009). Overall, the frequency of nicotine toxicity symptoms did not differ by dose group. Of specific symptoms, nausea was observed to be more frequent in the 63 mg/day dose group compared with placebo (p = .035). In conclusion, high-dose nicotine patch therapy resulted in a greater reduction of tobacco withdrawal symptoms among ST users using at least 3 cans per week. High-dose nicotine patch therapy is safe and well tolerated in this population of tobacco users.     

Recommendation for the assessment of tobacco craving and withdrawal in smoking cessation trials.

This paper addresses methodological issues in the assessment of nicotine withdrawal and craving in clinical trials of smoking cessation therapies. We define withdrawal as a syndrome of behavioral, affective, cognitive, and physiological symptoms, typically transient, emerging upon cessation or reduction of tobacco use and causing distress or impairment of behavioral function. Offset effects (effects related to removal of a direct nicotine effect) are sustained effects of cessation or reduction of tobacco use that cause distress or impairment. Withdrawal and craving are important as potential predictors of relapse, as mediators and markers of treatment effects, and as clinical phenomena in their own right. Symptoms recommended for assessment include craving, irritability, depression, restlessness, sleep disturbance, difficulty concentrating, increased appetite, and weight gain; anxiety deserves further study. We recommend reporting of data on each of these individual symptoms, and use of multiple-item assessments. Although some standardized measures of withdrawal have promising psychometric properties, no measure has yet fully established its reliability, validity, and broad applicability and, therefore, we do not currently favor universal adoption of any one measure. Assessment of objective indices of withdrawal (e.g., hormonal changes) is currently technically challenging and of unknown value. Although weekly assessment may suffice in some large trials, more intensive measurement can provide better sensitivity. Analyses of withdrawal should include baseline measures and be sensitive to potential instability in baseline. Analytic approaches should take into account potential bias when only abstinent subjects are examined. Conversely, heterogeneity should be considered when smoking subjects are included in intent-to-treat analyses. Withdrawal data from clinical trials focused on assessing abstinence rates may be biased because of progressive subject loss to dropout and relapse; different designs and approaches are needed to investigate the process and natural history of craving and withdrawal.     

Preliminary examination of tobacco withdrawal in adolescent smokers during smoking cessation treatment

Tobacco withdrawal symptoms have been shown to play a significant role in mediating relapse to smoking in adult smokers; however, few prospective studies have examined the course of tobacco withdrawal symptoms over time and their connection to lapse in adolescent smokers. Withdrawal symptoms were assessed weekly for 4 weeks in a sample of adolescent smokers participating in a pilot cessation intervention. Adolescent smokers experienced an exacerbation in overall withdrawal symptoms, particularly of cravings and restlessness, although symptoms were generally mild. The course of symptoms was different for boys and girls: Girls generally experienced a peak and subsequent decline in symptoms early in the establishment of abstinence, whereas boys experienced a constant level of symptoms that did not decline over the 4 weeks. Finally, withdrawal symptoms experienced on quit day were not related to lapse to smoking during the course of treatment for either boys or girls. These results suggest that although withdrawal symptoms may be uncomfortable, they may not be the most salient to a lapse to smoking for adolescent smokers attempting to quit. These findings have direct implications for the design and implementation of treatment of nicotine dependence in adolescent smokers.     

烟草种子亚显微结构及分类学意义

应用环境扫描电镜(ESEM)研究了73种烟草种子的形态和种皮表面结构特征。结果表明:烟草种子为中型(0.3～2mm),外形多样,颜色有6种:土黄色、浅褐色、褐色、浅棕色、棕色、深棕色。所研究的烟草种子表面纹饰有11种类型。种子表面微形态作为属内种的鉴别具有一定价值,种皮表面纹饰、微观附属物为烟草种的区分提供了新的依据。期望逐步建立起烟草种子微形态谱库,对烟属植物做出更合理的属下等级划分,为我国烟草种质资源的保护、贮藏、利用、鉴别、流通、选种、配种、种子信息查询等提供方便。     

Endotoxins in tobacco smoke: shifting tobacco industry positions.

In the 1980s, the tobacco industry started a campaign to divert attention away from secondhand tobacco smoke (SHS) as a major source of indoor air pollution in workplaces by highlighting the roles of other indoor air pollutants. The industry, working through "third parties," highlighted endotoxins, naturally occurring substances that cause numerous inflammatory reactions in humans, as an alternative explanation to SHS as causing indoor air problems. In 1995, Hasday and colleagues were the first to present findings that cigarette smoke contains significant quantities of endotoxins. This discovery surprised tobacco industry scientists. The 1999 publication of the full Hasday et al. findings received only limited media attention but got the full attention of Philip Morris scientists concerned about a new public health issue and a new basis for regulation of workplace smoking by the U.S. Occupational Safety and Health Administration, which already regulated workplace endotoxin exposures from other sources. Philip Morris undertook an internal endotoxin research project to test the Hasday et al. findings and to determine if endotoxin-free cigarettes were possible. Although experiments were conducted to remove endotoxin from the tobacco, there is no evidence that they were successful. Following confirmation of SHS as an important source of endotoxins, the scientist promoting endotoxins as an important indoor air pollutant for the tobacco industry softened his position on the role of endotoxins as indoor pollutants. The presence of endotoxins in SHS provides an additional mechanism for the adverse effects of SHS that should be researched further, and the risk of exposure should be assessed.     

Assessing internal tobacco industry knowledge of the neurobiology of tobacco dependence.

The recent availability of internal tobacco industry documents provides a significant resource for evaluating industry understanding of the pharmacological, psychosocial, and behavioral mechanisms underlying tobacco dependence. In this study, we catalog the range of efforts undertaken by tobacco manufacturers seeking knowledge of these mechanisms. Some areas of industry research, such as cellular and molecular studies of nicotine and its effects, are widely available in the open literature. Of greater interest are internal research projects that have demonstrated direct influence on product development. These include studies of smoker psychology and behavior, evoked-response studies of tobacco-delivered nicotine, the effects of sensory perception, dose-related effects, and the development of nicotine analogs and synergists. Our findings suggest extensive industry knowledge of mechanisms that determine smoker perception and behavior, and application of this knowledge in product development, including control of sensory response, uptake of nicotine, and product effects. Independent research recently has begun to consider the contributions of tobacco product ingredients and design factors to the determination of risk, severity, and prevalence of addiction. However, the application of these findings to cessation and treatment efforts is still quite limited. We conclude that clinical research would greatly benefit from further examination of the decades of knowledge accumulated by tobacco manufacturers.     

Depression during tobacco abstinence.

Many clinicians and scientists believe smoking cessation increases the risk of major depressive disorder (MDD), especially among those with a past history of the disorder. This literature review located seven empirical tests of this belief. All seven had significant methodological limitations. The incidence of MDD over 7-64 weeks postcessation was 0%-14% among all smokers who tried to stop, 3%-24% among smokers with a past history of MDD who tried to stop, and 1%-31% among smokers who became abstinent. Smokers with a past history of MDD were more likely to have postcessation MDD. Although some within-study comparisons suggest abstinence increased the incidence of MDD, a definitive conclusion cannot be made. Whether treatment with antidepressants prevented postcessation MDD also was unclear. This review makes methodological recommendations for more definitive studies.     

Effects of abstinence from tobacco: etiology, animal models, epidemiology, and significance: a subjective review.

This article updates a 1990 review of the effects of tobacco abstinence by reviewing (a) the etiology, (b) animal models, (c) the epidemiology, and (d) the clinical significance of tobacco abstinence effects. The author searched several databases to locate more than 3,500 citations on tobacco abstinence effects between 1990 and 2004. For brevity, the review does not evaluate these effects in regard to craving, hunger, or performance. Data collection and study conclusions were based on the author's subjective judgment. The most validated etiological model suggests that withdrawal is related to decreased dopaminergic activity, but how this relates to nicotine receptor changes is unclear. The two most validated animal models describe increases in intracranial self-stimulation thresholds or observable physical signs. Significant withdrawal symptoms occur in at least half of smokers when they try to quit. Withdrawal appears to produce clinically significant distress and impairment. Increases in depression after abstinence, but not other symptoms, prospectively predict relapse. In conclusion, the proposed neurobiological mechanisms by which withdrawal occurs leave several unanswered questions. Although animal models have been developed, how well they mimic withdrawal in humans is unclear. Tobacco withdrawal is common and can be distressing. Withdrawal-induced depression appears to undermine the smoker's ability to remain abstinent.     

固相微萃取/气相色谱/质谱法定性定量分析烟叶中香味物质的研究

采用固相微萃取/毛细管气相色谱/质谱法(SPME/GC/MS)对烟草中的挥发性香味物质进行了分析研究,共鉴定了烟草中60余种挥发性成分。对我国主要烟区不同类型、不同等级的烟叶和国外不同等级的白肋烟叶中挥发性香味物质进行了定性定量分析,结果表明:对不同类型烟叶样品挥发性香味物质的分析,在定性和定量上均有差异;对同种类型、不同等级的烟叶样品挥发性香味物质的差异,大都在定量上,并无定性上的差异。该方法集采样、萃取、浓缩、进样于一体,操作简单、快速,重现性好等特点,为烟草挥发性香味成分分析提供了一种可供参考的方法。      

Cost-effectiveness of self-help smokeless tobacco cessation programs.

This study assessed the cost-effectiveness of two low-intensity programs for quitting smokeless tobacco, based on results of a randomized trial with 1,069 volunteer participants. Cost data were collected for two levels of intervention: manual only (a self-help manual) and assisted self-help (the manual plus a videotape and two supportive phone calls from tobacco cessation counselors). Incremental cost-effectiveness ratios were calculated for assisted self-help vs. quitting on one's own, using the manual-only quit rate and data from another study as alternative proxies for no intervention. A threshold analysis was conducted to determine the spontaneous quit rate at which the manual-only intervention becomes more cost-effective than assisted self-help. The cost to provide and receive the assisted self-help intervention averaged US $56 per participant vs. $20 for the manual-only intervention (societal perspective, Year 2000 dollars). Estimates for incremental cost per quit for the assisted self-help intervention ranged from $922 to $1,758, depending on the proxy used for no intervention. The manual-only intervention was more cost-effective than assisted self-help if quitting among motivated chewers who do not receive treatment does not exceed 3.4%. Support from a wife or partner added little cost to a quit attempt for male chewers ($3-$4). Providing a manual, video, and brief phone counseling to smokeless tobacco users who want to quit is a reasonable use of health care resources. The self-help quitting guide also may be a cost-effective treatment, but it remains to be demonstrated whether it is more effective than quitting on one's own.     

Demand analysis of tobacco consumption in Malaysia.

We estimated the price and income elasticity of cigarette demand and the impact of cigarette taxes on cigarette demand and cigarette tax revenue in Malaysia. The data on cigarette consumption, cigarette prices, and public policies between 1990 and 2004 were subjected to a time-series regression analysis applying the error-correction model. The preferred cigarette demand model specification resulted in long-run and short-run price elasticities estimates of -0.57 and -0.08, respectively. Income was positively related to cigarette consumption: A 1% increase in real income increased cigarette consumption by 1.46%. The model predicted that an increase in cigarette excise tax from Malaysian ringgit (RM) 1.60 to RM2.00 per pack would reduce cigarette consumption in Malaysia by 3.37%, or by 806,468,873 cigarettes. This reduction would translate to almost 165 fewer tobacco-related lung cancer deaths per year and a 20.8% increase in the government excise tax revenue. We conclude that taxation is an effective method of reducing cigarette consumption and tobacco-related deaths while increasing revenue for the government of Malaysia.     

Smokeless tobacco topography and toxin exposure.

This study examined the relationship between oral smokeless tobacco (ST) topographical measures and biomarkers of tobacco and carcinogen exposure. During 2 weeks of baseline ad libitum ST use, 54 male participants (mean age=32.1+/-7.5 years) were required to record the time each dip was placed in and removed from their mouths. Urine samples were collected twice during baseline and analyzed for nicotine, cotinine, and their glucuronides (total nicotine and total cotinine) and for metabolites of the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides (total NNAL). The results suggest that frequency and duration measures of ST use (p<.01 to p<.001), particularly total dip duration, are significantly correlated with total cotinine, total nicotine, and total NNAL. These results suggest that how long a ST user has tobacco in his mouth is most predictive of tobacco toxin exposure.     

Tobacco-specific nitrosamines in new tobacco products.

New tobacco products, designed to attract consumers who are concerned about the health effects of tobacco, have been appearing on the market. Objective evaluation of these products requires, as a first step, data on their potentially toxic constituents. Tobacco-specific nitrosamines (TSNAs) are an important class of carcinogens in tobacco products, but virtually no data were available on their levels in these products. In the present study, we analyzed several new products-Ariva, Stonewall, Exalt, Revel, Smokey Mountain, and Quest-for TSNAs and compared their TSNA levels with those in nicotine replacement products and conventional smokeless tobacco and cigarette brands. TSNAs were not detected in Smokey Mountain, which is a tobacco-free snuff product. The lowest levels among the new products containing tobacco were in Ariva and Stonewall (0.26-0.28 microg/g wet weight of product). The highest levels in the new products were found in Exalt (3.3 microg/g tobacco), whereas Revel and Quest had intermediate amounts. Only trace amounts were found in nicotine replacement products, and conventional brands had levels consistent with those reported in the literature. These results demonstrate that TSNA levels in new tobacco products range from relatively low to comparable with those found in some conventional brands.     

Playing hide-and-seek with the tobacco industry.

Despite many peer-reviewed works that draw on tobacco industry documents that have now been made public, questions remain about how complete a picture has emerged. We present a conceptual framework that identifies and evaluates tobacco industry efforts to conceal information. Widespread document destruction like that in recent litigation in Australia is just one of more than a dozen tobacco industry efforts to prevent access, or at least timely access, to documents. Industry efforts range from small, locally employed initiatives to company-wide tactics. Some efforts, such as using "oral only" procedures, scrambling telephone lines, or involving lawyers in scientific projects, are preemptive. Others seek to deal with already existing documents by invoking bogus claims of legal privilege, stipulating "read then destroy" for memos, and rewriting problematic memos. That evidence of concealment has, in fact, been found in tobacco company archives attests to the futility of attempting to control the flow of millions of pieces of paper among tens of thousands of employees. However, researchers have yet to reveal the full story: We know of the industry's failures in concealing information, but not its successes. The industry's objective is not destruction of information per se, but prevention of public disclosure of that information. Exposing the tobacco industry's many approaches to concealment provides greater insight into companies' intentions and potential means for stripping away that concealment.     

Adult recall of tobacco advertising on the Internet.

This study examined the prevalence and characteristics of New Jersey adults who reported seeing tobacco products advertised on the Internet and described the means by which these products were advertised. Data were analyzed from the New Jersey Adult Tobacco Survey (NJATS), a repeated, cross-sectional, random-digit-dial telephone survey conducted with a statewide representative sample. We used logistic regression to determine factors associated with recall of tobacco Internet advertising, adjusting for demographics, smoking behavior variables, and receipt of tobacco industry direct mail. Participants included 3,930 adults who completed the 2001 NJATS, 4,004 adults who completed the 2002 survey, and 3,062 adults who completed the 2005 survey. The proportion of adult Internet users reporting exposure to tobacco product advertising on the Internet has increased each year (6.9% in 2001, 15.6% in 2002, 17.8% in 2005). Based on 2005 data, recall of tobacco product advertising on the Internet was higher among males young adults aged 18-24 years, Asians, adults who reported receipt of direct mail advertising, and adults with a postcollege education. In addition, adult Internet users most often reported seeing tobacco products advertised on the Internet via pop-up or banner ads (60.7%), followed by E-mail messages (24.6%), and Web sites (14.9%). Recall of tobacco advertising by Internet users increased between 2001 and 2005 and was particularly high among certain subgroups. An urgent need exists for expanded surveillance of Internet tobacco sales and marketing practices.     

Assessment of environmental tobacco smoke contamination in public premises: significance of 2,5-dimethylfuran as an effective marker

Contamination by environmental tobacco smoke (ETS) on premises where smoking is permitted is evaluated. Although all target VOCs evaluated show significant differences between smoking and nonsmoking indoors, the results obtained indicate that 2,5-dimethylfuran is the most appropriate and effective marker of ETS contamination given that this compound is only detected in environments where people have smoked and so the detection of this compound cannot be attributed to other contamination sources such as traffic. Moreover, the air levels of this compound due to coffee aroma are below the detection limits for this methodology. A preliminary study is performed to evaluate whether 2,5-dimethylfuran, a smoking breath biomarker, can be detected in passive smokers working in smoking environments. The compound was continuously detected in the breath of nonsmoking employees after being in direct contact with ETS for just a few hours. The Tedlar gas sampling bags had 5% loss of 2,5-dimethylfuran after 3 h of storage, which we took as the maximum recommended period for air sample storage.     

部分烟草种质主要病害抗性分析

通过频率分布及多样性评价,对1000多份种质的7个主要病害抗性进行了分析.结果表明,我国烟草种质资源大部分均为感病以上品种.TMV抗性资源相对较丰富,高抗或免疫种质达17%.其余病害抗病资源中,多为抗病或中抗,高抗种质很少,不到2%.我国主要病害抗性种质较为匮乏.