Non-nicotine constituents in cigarette smoke extract enhance nicotine addiction through monoamine oxidase A inhibition

Tobacco addiction has been largely attributed to nicotine, a component in tobacco leaves and smoke. However, extensive evidence suggests that some non-nicotine components of smoke should not be overlooked when considering tobacco dependence. Yet, their individual effect and synergistic effect on nicotine reinforcement remain poorly understood. The study herein focused on the role of non-nicotine constituents in promoting the effects of nicotine and their independent reinforcing effects. Denicotinized cigarettes were prepared by chemical extracting of cut tobacco, and the cigarette smoke extracts (CSE, used as a proxy for non-nicotine ingredients) were obtained by machine-smoking the cigarettes and DMSO extraction. The compositions of harmful components, nicotine, and other minor alkaloids in both cut tobacco and the CSE of experimental denicotinized cigarettes were examined by GC-MS, and compared with 3R4F reference cigarettes. individually and in synergy with nicotine were determined by conditioned place preference (CPP), dopamine (DA) level detection, the open field test (OFT), and the elevated plus maze (EPM). Finally, the potential enhancement mechanism of non-nicotinic constituents was investigated by nicotine metabolism and monoamine oxidase A (MAOA) activity inhibition in the striatum of mice and human recombinant MAOA. Thenicotine content in smoke from the experimental denicotinized cigarettes (under ISO machine-smoking conditions) was reduced by 95.1% and retained most minor alkaloids, relative to the 3R4F reference cigarettes. It was found that non-nicotine constituents increased acute locomotor activities. This was especially pronounced for DA levels in NAc and CPP scores, decreased the time in center zone. There were no differences in these metrics with DNC group when compared to the NS group. Non-nicotine constituents alone did not show reinforcing effects in CPP or striatum DA levels in mice. However, in the presence of nicotine, non-nicotine constituents further increased the reinforcing effects. Furthermore, non-nicotine constituents may enhance nicotine's reinforcing effects by inhibiting striatum MAOA activity rather than affecting nicotine metabolism or total striatum DA content in mice. These findings expand our knowledge of the effect on smoking reinforcement of non-nicotine constituents found in tobacco products.

Behavioural programmes for cigarette smoking cessation: investigating interactions between behavioural, motivational and delivery components in a systematic review and component network meta-analysis

AIMS

To investigate the comparative and combined effectiveness of four types of components of behavioural interventions for cigarette smoking cessation: behavioural (e.g. counselling), motivational (e.g. focus on reasons to quit), delivery mode (e.g. phone) and provider (e.g. nurse).

DESIGN

Systematic review and component network meta-analysis of randomised controlled trials identified from Cochrane reviews. Interventions included behavioural interventions for smoking cessation (including all non-pharmacological interventions, e.g. counselling, exercise, hypnotherapy, self-help materials), compared with another behavioural intervention or no support. Building on a 2021 review (CD013229), we conducted three analyses, investigating: comparative effectiveness of the components, whether models that allowed interactions between components gave different results to models assuming additivity, and predicted effect estimates for combined effects of components that had showed promise but where there were few trials.

SETTING

Community and health-care settings.

PARTICIPANTS

Adults who smoke tobacco.

MEASUREMENTS

Smoking cessation at ≥6 months, preferring sustained, biochemically validated outcomes where available.

FINDINGS

Three hundred and twelve trials (250 563 participants) were included. Fifty were at high risk of bias using Cochrane risk of bias tool, V1 (ROB1); excluding these studies did not change findings. Head-to-head comparisons of components suggested that support via text message (SMS) compared with telephone (OR 1.48, 95% CrI 1.13-1.94) or print materials (OR 1.44, 95% CrI 1.14-1.83) was more effective, and individual delivery was less effective than delivery as part of a group (OR 0.78, 95% CrI 0.64-0.95). There was no conclusive evidence of synergistic or antagonistic interactions when combining components that were commonly used together. Adding multiple components that are commonly used in behavioural counselling suggested clinically relevant and statistically conclusive evidence of benefit. Components with the largest effects that could be combined, but rarely have been, were estimated to increase the odds of quitting between two and threefold. For example, financial incentives delivered via SMS, with tailoring and a focus on how to quit, had an estimated OR of 2.94 (95% CrI 1.91-4.52).

CONCLUSIONS

Among the components of behavioural support for smoking cessation, behavioural counselling and guaranteed financial incentives are associated with the greatest success. Incorporating additional components associated with effectiveness may further increase benefit, with delivery via text message showing particular promise.

Malondialdehyde Level and Tissue Apoptosis Count as an Early-Detection Marker of Oral Potentially Malignant Disorders

OBJECTIVES

 The malondialdehyde (MDA) level and TA count represent the progression of oral potentially malignant disorders (OPMD) to malignancy and thus may be used as an indicator of oral epithelial dysplasia (OED). This study aimed to determine the MDA level and tissue apoptosis (TA) count in oropharyngeal tissue of Wistar rats exposed to sidestream cigarette smoke.

MATERIALS AND METHODS

 Wistar rats were divided into three groups: T4 group (4-week cigarette smoke exposure), T8 group (8-week cigarette smoke exposure), and control group, which was not exposed to cigarette smoke. The oropharyngeal tissue of the rats from each group was examined histopathologically to count the number of apoptotic cells, and then the blood serum was made to measure the MDA level.

STATISTICAL ANALYSIS

 Bonferroni test was performed to see the differences in each group for MDA level. While the data from tissue apoptosis were analyzed using Mann-Whitney U test for the significance. All data were considered significant if p < 0.05.

RESULTS

 The MDA level and TA count increased as the duration of cigarette smoke exposure increased. In the T8 group, the MDA level and TA count were significantly higher compared with the T4 and control groups with a p-value < 0.05.

CONCLUSIONS

 Exposure to sidestream cigarette smoke increased the TA count and MDA level in the oropharyngeal tissue of Wistar rats. The TA count and MDA level may be used as markers of OPMD.

Developing a Smoking Cessation Intervention for People With Severe Mental Illness Treated by Flexible Assertive Community Treatment Teams in the Netherlands: A Delphi Study

BACKGROUND

There is still limited evidence on the effectiveness and implementation of smoking cessation interventions for people with severe mental illness (SMI) in Dutch outpatient psychiatric settings. The present study aimed to establish expert consensus on the core components and strategies to optimise practical implementation of a smoking cessation intervention for people treated by Flexible Assertive Community Treatment (FACT) teams in the Netherlands.

DESIGN

A modified Delphi method was applied to reach consensus on three core components (behavioural counselling, pharmacological treatment and peer support) of the intervention. The Delphi panel comprised five experts with different professional backgrounds. We proposed a first intervention concept. The panel critically examined the evolving concept in three iterative rounds of 90 min each. Responses were recorded, transcribed verbatim and thematically analysed.

RESULTS

Overall, results yielded that behavioural counselling should focus on preparation for smoking cessation, guidance, relapse prevention and normalisation. Pharmacological treatment consisting of nicotine replacement therapy (NRT), Varenicline or Bupropion, under supervision of a psychiatrist, was recommended. The panel agreed on integrating peer support as a regular part of the intervention, thus fostering emotional and practical support among patients. Treatment of a co-morbid cannabis use disorder needs to be integrated into the intervention if indicated. Regarding implementation, staff's motivation to support smoking cessation was considered essential. For each ambulatory team, two mental health care professionals will have a central role in delivering the intervention.

CONCLUSIONS

This study provides insight into expert consensus on the core components of a smoking cessation intervention for people with SMI. The results of this study were used for the development of a comprehensive smoking cessation program.

Identifying active ingredients, working mechanisms and fidelity characteristics reported in smoking cessation interventions in Dutch primary care: a systematic review

Background

Evidence-based smoking cessation interventions provided by healthcare professionals can be successful in helping citizens to quit smoking. Yet, evidence is needed about the active ingredients of these interventions, how these ingredients work and how they are implemented in practice. Such knowledge is required to effectively support healthcare professionals to optimally put evidence-based smoking cessation interventions to (inter)national practice.

Objective

To identify active ingredients (including behavior change techniques), mechanisms of action and implementation fidelity reported in smoking cessation interventions in Dutch primary care settings and to relate these to intervention effectiveness.

Methods

A systematic review was conducted by searching nine national intervention or funding databases, five international scientific databases and consulting 17 national smoking cessation experts. Out of 1066 identified manuscripts, 40 interventions were eligible for this review. Based on published protocols, information regarding behavior change techniques and mechanisms of action was systematically abstracted. Additionally, information regarding study characteristics and other active ingredients, effects on smoking behavior and implementation fidelity was abstracted. Comparative effectiveness concerning abstracted intervention characteristics was qualitatively explored.

Results

Active ingredients, mechanisms of action and implementation fidelity were moderately to poorly reported. Interventions applying behavior change techniques and interventions with a single behavioral target (i.e. smoking-only versus multiple behaviors) seemed to provide stronger evidence for successfully changing smoking behavior.

Conclusion

Attention to and reporting on interventions’ active ingredients (e.g. behavior change techniques), mechanisms of action and implementation fidelity are prerequisites for developing more effective evidence-based smoking cessation interventions to be successfully implemented in primary healthcare.

Implications

This systematic review provides an overview of smoking cessation interventions in Dutch primary care settings, identified since the year 2000. Smoking cessation support is offered in various forms, but our qualitative findings show that interventions including more behavior change techniques and interventions targeting only smoking cessation (compared to multiple behaviors) might be more effective. Results also show that—based on available intervention reports—it is difficult to distinguish patterns of active ingredients (such as behavior change techniques), mechanisms of action and fidelity of implementation in relation to interventions’ effectiveness. This means (quality of) reporting on these intervention characteristics should improve.

Application of estimated oral health indices in adolescents with tobacco addiction

It is known that every day 2,500 children under the age of 18 try their first cigarette, and more than 400 of them become new, regular smokers, and half of them will die from this addiction in the future.

AIM

The aim of the study is to determine changes in the indices of dental status in adolescents with tobacco smoking.

MATERIALS AND METHODS

The study involved 54 adolescents aged 12 to 18 years. They were divided into the main group of 25 adolescents with a smoking experience of 1 to 3 years, and a control group of 29 adolescents who were physically healthy at the time of the study and had never smoked. During their visit to dentist for a preventive examination such indexes were investigated as simplified Oral Hygiene Index (OHI-S) (Greene-Vermillion), papillary-marginal-alveolar index (PMA), Fedorov-Volodkina index, caries severity index, index of the need for treatment of periodontal disease and biophysical methods of oral fluid research: rate of salivation, elasticity, pH of oral fluid.

RESULTS

The changes in dental status identified in the study in adolescents with addiction to smoking indicated certain aspects of the risk of developing dental diseases in this group of patients with prevalence of periodontal inflammation. The most vulnerable, with a short history of smoking, were periodontal tissues. It could indicate the direct effect of tobacco smoke on the microcirculation of the gums.

CONCLUSIONS

Smoking is a risk factor for periodontal health in adolescents. The periodontal inflammation of various severities was established in children and adolescents aged 12-18 years old. Evaluation of oral health indices has been estimated from 0.79 ± 0.19 to 1.9 ± 0.05 (p<0.05) for Greene-Vermilion, from 1.5 ± 0.41 to 2.5 ± 0.59 (p<0.05) for Fedorov-Volodkina, from 12.0± 2.06% to 36.0 ± 2.04% to for PMA (p<0.05) as result of adolescent smoking. Simultaneously we didn't estimate significant difference for caries severity in investigated groups.

The level of effectiveness of Polish legislation relating to health protection against the consequences of tobacco use

The purpose of this work is to analyze the regulatory environment for tobacco use, with particular reference to changes made in the last 10 years. An attempt was made to answer the question of the extent to which the regulatory environment has a real impact on the achievement of the objective set out in the existing legal provisions, which is to protect the health and rights of the persons concerned. An analytical method was used in the work to assess the application of legal principles. A method of analyzing the current line of jurisprudence was also used. In the process of final evaluation of public utilities, certain functional methods were used. The assessment was subjected to Polish law, within the scope of the currently binding Act on Health Protection Against the Consequences of Using Tobacco and Tobacco Products of 1995. The study states that the provisions of this Act are only a formal guarantee of protection. The liability arising from the application of its standard is illusory because the procedure for imposing penalties is ineffective. The pursuit of any property claims related to violation of the rights of related entities, as envisaged in this Act, is complicated. This does not apply to a case which is not affected by the decision. Int J Occup Med Environ Health. 2020;33(5):599-610.

A randomized controlled trial to compare group motivational interviewing to very brief advice for the effectiveness of a workplace smoking cessation counseling intervention

BACKGROUND

Studies show that smokers have a lower work performance due to time spent smoking, increased fatigue perception and are more absent from work due to smoking-related diseases. The workplace could represent an important location to promote smoking cessation.

METHODS

This study is a multi-center, controlled trial for smoking cessation counseling at the participants' workplace, where 656 randomized participants received four sessions of group motivational interviewing or four sessions of very brief advice and were followed up for 52 weeks.

RESULTS

The Continuous Quit Rate (CQR) was higher for the smoking cessation counseling group than for the very brief advice group during weeks 9 to 12 (17.5% vs. 3.6%) weeks 9 to 24 (13.4% vs. 3.4%) and weeks 9 to 52 (10.3% vs. 3.1%).

CONCLUSIONS

This study demonstrated that motivational interviewing is an efficacious smoking cessation approach for smokers at their workplace. The short-term and long-term cessation rate of the intervention of the smoking cessation counseling group exceeded that of very brief advice.

Feasibility, uptake and impact of a hospital-wide tobacco addiction treatment pathway: Results from the CURE project pilot

INTRODUCTION

Providing comprehensive tobacco addiction treatment to smokers admitted to acute care settings represents an opportunity to realise major health resource savings and population health improvements.

METHODS

The CURE project is a hospital-wide tobacco addiction treatment service piloted in Wythenshawe Hospital, Manchester, UK. The core components of the project are electronic screening of all patients to identify smokers; the provision of brief advice and pharmacotherapy by frontline staff; opt-out referral of smokers to a specialist team for inpatient behavioural interventions; and continued support after discharge.

RESULTS

From 01 October 2018 to 31 March 2019, 92% (13,515/14,690) of adult admissions were screened for smoking status, identifying 2,393 current smokers. Of these, 96% were given brief advice to quit by the admitting team. Through the automated 'opt-out' referral process, 61% patients completed inpatient behavioural interventions with a specialist cessation practitioner (69% within the first 48 hours of admission). Overall, 66% of smokers were prescribed pharmacotherapy. Over one in five of all smokers admitted during this pilot reported that they were abstinent from smoking 12 weeks after discharge (22%) at a cost £183 per quit.

DISCUSSION

National implementation of this cost-effective programme would be likely to generate substantial benefits to public health.

A retrospective cohort study of the prevalence of anxiety and agitation in schizophrenic smokers and the unmet needs of smoking cessation programs

Achieving abstinence in schizophrenic smokers using a combination of medications and cognitive behavioral therapy is feasible; however, abstinence rates are significantly lower compared to the general population and studies are scanty. Additionally, maintaining sustained abstinence and preventing relapse is a major limiting factor and represents key tasks in managing tobacco dependence in schizophrenic patients. Several theories have been postulated to explain the higher tendency of tobacco use among schizophrenic individuals. Schizophrenic patients may use nicotine as a "self-medication" strategy to improve negative symptoms of schizophrenia. However, studies suggest that although nicotine may act as an anxiolytic acutely, chronic use of nicotine may lead to increased anxiety with the possibility of increased catecholamines, which is confirmed with the prevalence of tachycardia and hypertension in smokers in general. On this basis, the main objective of our present study was to assess anxiety in schizophrenic smoking and nonsmoking patients by comparing the number of anxiety and agitation episodes and evaluating the amount of antianxiety/antiagitation medication used by each group. A separate objective was to document the unmet needs of smoking cessation programs in treating schizophrenic patients. Consequently, in the present retrospective cohort study, it was observed that schizophrenic smokers tend to have higher anxiety episodes and utilize as-needed medications at a higher frequency compared to nonsmokers for the relief of anxiety and agitation symptoms. Further research is warranted to examine these results on a larger scale.

Mental health service user and staff perspectives on tobacco addiction and smoking cessation: A meta-synthesis of published qualitative studies

WHAT IS KNOWN ON THE SUBJECT?: There are high rates of tobacco smoking in people living with mental illness, and rates are much higher than the general population. People living with mental illness experience high rates of cardiovascular disease and other physical health problems as a result of tobacco smoking. There is a lack of evidence on successful interventions for reducing the rates of smoking in people living with mental illness. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: A meta-synthesis of data from a number of studies to support mental health nurses to access data quickly and support the translation of findings into practice. Studies found staff working in mental health services expressed they did not have the confidence to adequately address smoking cessation for people living with mental illness. People living with mental illness would like support and encouragement support to help them achieve successful smoking cessation. People living with mental illness want support from mental health service staff to increase their confidence in smoking cessation rather than mainstream smoking cessation services. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Existing evidence-based interventions for smoking cessation has had limited impact on the smoking rates of people living with mental illness. Research is needed into innovative smoking cessation interventions and the service delivery of these interventions for people living with mental illness. Interventions to support people living with mental illness in smoking cessation could be part of mainstream mental health service delivery. Opportunities for smoking cessation training for mental health service staff could be provided.

ABSTRACT

Introduction People with mental illness are up to three times more likely to smoke and experience greater challenges and less success when trying to quit and therefore have higher risk of smoking-related morbidity and mortality. There is a lack of evidence on successful interventions to reduce the smoking rates in people living with serve mental illness. A meta-synthesis was undertaken to summarize the data from multiple studies to inform the development of future smoking cessation intervention studies. Methods MEDLINE, PsycINFO, Embase and CINAHL were searched in March 2017. A total of 965 titles and abstracts were screened for inclusion with 29 papers reviewed in full and 15 studies that met inclusion criteria. Included studies were assessed for quality using the Critical Appraisal Skills Programme tool. Key data across studies were examined and compared, and a thematic analysis was conducted. Results Analysis and synthesis developed five analytical themes: environmental and social context, living with a mental health illness, health awareness, financial awareness and provision of smoking cessation support. Themes generated the interpretive construct: "Whose role is it anyway?" which highlights tensions between staff perspectives on their role and responsibilities to providing smoking cessation support and support service users would like to receive. Relevance to mental health nursing Routine smoking cessation training for mental health professionals and research on innovative smoking cessation interventions to support people living with mental illness are needed. The Cochrane tobacco group has not found sufficient direct evidence of existing evidence-based interventions that have beneficial effect on smoking in people living with mental illness. With this in mind, mental health professionals should be encouraged to engage in future research into the development of new interventions and consider innovative harm reduction strategies for smoking into their practice, to reduce the morbidity and mortality many people living with mental illness experience from tobacco smoking.

Tobacco Use Decreases Visual Sensitivity in Schizophrenia

Smoking prevalence in patients who are diagnosed with schizophrenia (SCZ) is higher than in the general population. Chronic tobacco use in SCZ patients may reduce the side effects of antipsychotic drugs, thus serving as a self-medication for such side effects. Understanding the ways in which chronic tobacco use influences visual sensitivity has clinical implications, which may serve as a tool for non-invasively diagnosing early-stage visual processing deficits. The present study evaluated the effects of chronic tobacco use on visual sensitivity in SCZ patients. Our purpose was to provide new directions for future research, mainly psychophysical and electrophysiological studies. In the present study, 40 smoker controls (SC), 20 SCZ tobacco users, and 20 SCZ tobacco nonusers were recruited from the Psychosocial Care Center. Visual sensitivity was compared between both SCZ groups and the SC group. Patients with SCZ who were chronic tobacco users presented lower visual sensitivity for chromatic (p < 0.001) and achromatic (p < 0.001) stimuli compared with the other groups. Our findings highlight the need to evaluate possible addictive behavior in patients with SCZ, which may contribute to public policies that seek to improve the quality of life of SCZ patients and their families.

Determinants of smoking cessation and abstinence in a Russian smoking-cessation center

INTRODUCTION

Smoking prevalence in Russia is one of the highest in the world. It leads to significant damage to the National Health Service. The purpose of the present research was to assess the effectiveness of a qualified smoking-cessation (SC) center in Moscow, and to identify the main determinants of smoking cessation.

METHODS

The subjects of this study were a cohort of smokers (n=524) who had attended the SC service in Moscow between 2012-2015. They were followed, for at least 6 months after receiving the professional counselling in smoking cessation, to assess the results of the assistance and to identify determinants of successful smoking cessation.

RESULTS

Of the smokers, 19% succeeded in reducing by more than half the number of smoked cigarettes, more than 46% of patients completely stopped smoking for different terms: 38% for more than a month and 24% for more than half a year. Odds ratios (ORs) indicated that the probability of successful smoking cessation significantly increased if there was a previous success in smoking cessation: OR 3.71 (95% CI 1.70-8.12); and if there was a high level of motivation to stop smoking OR 4.3 (95% CI 1.92-5.61). The probability of successful smoking cessation decreased with intensity of smoking > 10 cigarettes a day: OR 0.57 (95% CI 0.31-1.02); and an elevated (>7 points) Fagerström-test score OR 0.64 (95% CI 0.37-1.07).

CONCLUSIONS

Degree of motivation and willingness to quit smoking were the principal determinants of the effectiveness in the attempt to quit smoking within our study cohort.

Does cigarette reduction while using nicotine replacement therapy prior to a quit attempt predict abstinence following quit date?

BACKGROUND AND AIMS

Previous studies have reported that people who use a smoking cessation medication while smoking and reduce cigarette consumption spontaneously are three times more likely to stop smoking after a quit date. The aim was to replicate this and assess whether it arises because of willed effortful reduction rather than unwilled reduced drive to smoke caused by medication.

DESIGN

Secondary analysis of a trial where participants were randomised to smoke as normal or reduce by 75% over 2 weeks prior to quit date, using nicotine replacement therapy (NRT) in both arms.

SETTING

Thirty-one UK primary care practices.

PARTICIPANTS

A total of 517 adult smokers seeking quitting support in the carbon monoxide (CO) analyses and 421 in the cigarettes/day analyses.

MEASUREMENTS

Russell Standard abstinence was recorded 4 weeks after quit date. The randomized groups were combined and the association between reduction and abstinence examined. The second analysis assessed whether this association differed by whether smokers were, or were not, instructed to reduce.

FINDINGS

In all participants, there was no evidence that reducing cigarettes/day or CO by at least half compared with not reducing predicted abstinence at 4 weeks [risk ratio (RR) = 0.88; 95% confidence interval (CI) = 0.68-1.14 and RR = 1.20; 95% CI = 1.00-1.44, respectively]. However, in smokers instructed to reduce, CO reduction was associated with 4-week abstinence (RR = 1.52; 95% CI = 1.16-2.00), but not among people advised not to reduce (RR = 0.91; 95% CI = 0.67-1.24).

CONCLUSIONS

Smoking reduction prior to a target quit date while on a smoking cessation medication may only predict subsequent abstinence when smokers are consciously attempting to reduce.

Treatment with a nicotine vaccine does not lead to changes in brain activity during smoking cue exposure or a working memory task

AIMS

To assess whether immunization attenuates nicotinic stimulation of the brain and elucidate brain and behavioural responses during exposure to smoking cues and a working memory task.

DESIGN

Randomized, placebo-controlled parallel-group, repeated-measures design.

SETTING

Maastricht University, the Netherlands.

PARTICIPANTS

Forty-eight male smokers were randomized to receive five injections with either 400 μg/ml of the 3'-aminomethylnicotine Pseudomonas aeruginosa r-Exoprotein-conjugated vaccine or placebo. Subjects were tested on two occasions, once after a nicotine challenge and once after a placebo challenge, and were asked to refrain from smoking 10 hours before testing.

MEASUREMENTS

Reaction-times and accuracies were recorded during an n-back task. Moreover, regional blood oxygenated level-dependent (BOLD) response was measured during this task and during smoking cue exposure.

FINDINGS

Greater activation was found in response to smoking cues compared to neutral cues in bilateral trans-occipital sulcus (P < 0.005); however, this effect did not survive correction for multiple comparisons. There was no difference in brain activity to smoking cues between the treatment groups and no effects of acute nicotine challenge were established. For the n-back task we found working memory load-sensitive increases in brain activity in several frontal and parietal areas (P < 0.0025). However, no effects of immunization or nicotine challenge were observed.

CONCLUSION

No significant effects of immunization on brain activity in response to a nicotine challenge were established. Therefore this vaccine is not likely to be an effective aid in smoking cessation.

The Cochrane tobacco addiction group

The Cochrane Tobacco Addiction Group produces up-to-date systematic reviews of interventions for the cessation and prevention of tobacco use. Many of our Cochrane Reviews have also been published in scientific journals. Our review prioritization schedule is informed by our group's experience and expertise as well as identifying topics for reviews via regular searches of current scientific literature and from other news sources, such as the Action on Smoking and Health updates. The Cochrane Register of Studies allows identification of new trials, which might be eligible for review updates. Everyday challenges include timely publishing and updating of our reviews, and ensuring compliance to Cochrane methodological expectations of Cochrane intervention review standards. We are grateful for the contributions of our authors and peer reviewers, with whom we aim to have close working and productive relationships. We look forward to continuing our contribution toward a reliable evidence base on interventions to combat tobacco addiction.

Prevalence of tobacco use among adults in Egypt, 2009

INTRODUCTION

We assessed the differences in overall use of tobacco and in the use of various tobacco products, by sex and by frequency of use across various demographic groups.

METHODS

We used data from the Global Adult Tobacco Survey (GATS), conducted in 2009 in Egypt. The data consist of answers to GATS by 20,924 respondents from a nationally representative, multistage probability sample of adults aged 15 years or older from all regions of Egypt. Current tobacco use was defined as current smoking or use of smokeless tobacco products, either daily or occasionally. We analyzed the differences in current cigarette, shisha, and smokeless tobacco use by sex and frequency of use (daily or occasional); and by demographic characteristics that included age, region, education level and employment status.

RESULTS

Overall, 19.7% of the Egyptian population currently use some form of tobacco. Men (38.1% [95% confidence interval (CI) 36.8-39.4]) are much more likely than women (0.6% [95% CI 0.4-0.9]) to use tobacco. Almost 96% of men who use tobacco, do so daily. Men are more likely to use manufactured cigarettes (31.8% [95% CI 30.6-33.1]) than shisha (6.2% [95% CI 5.6-6.9]) or smokeless tobacco (4.1% [95% CI 3.4-4.8]). Few women use tobacco (cigarettes (0.2%), shisha (0.3%) and smokeless tobacco (0.3%)); however, all women who currently smoke shisha, do so daily. Lower educational status, being between ages 25-64 and being employed predicted a higher use of tobacco.

CONCLUSION

Egypt has implemented several initiatives to reduce tobacco use. The World Health Organization (WHO) MPOWER technical package, which aims to reverse the tobacco epidemic, is implemented at various levels throughout the country. Our findings show that there is significant variation in the prevalence of tobacco use and types of tobacco used by adult men and women in Egypt. GATS data can be used to better understand comparative patterns of tobacco use by adults, which in turn can be used to develop interventions.

The reinforcement threshold for nicotine as a target for tobacco control

BACKGROUND

Cigarette smoking represents an enormous public health problem worldwide that leads to over 5 million deaths per year. The gradual reduction of the nicotine content of cigarettes below the threshold that is required to develop addiction is one strategy that might substantially reduce the number of addicted smokers and prevent adolescents from becoming addicted to nicotine (Benowitz and Henningfield, 1994). While the potential public health benefits of this approach are enormous, the guiding concepts and relevant empirical evidence needed to support the implementation of a nicotine reduction policy require a critical examination.

METHODS

The purpose of this paper is to briefly review the current concepts and research regarding nicotine reduction while also discussing the utility of the addictive threshold for nicotine in this approach. The accurate determination of the nicotine addiction threshold presents some conceptual challenges as there is a lack of consensus on how to best measure nicotine addiction. This difficulty can impede the progress for developing a science-based tobacco control policy. As an alternative, the nicotine reinforcement threshold is a relatively clear concept, and well-accepted methods and criteria are available to measure nicotine reinforcement.

RESULTS

However, there are many gaps in our current knowledge concerning the nicotine reinforcement threshold in humans. The threshold for nicotine reinforcement remains to be determined in controlled settings using different populations of current or potential tobacco users. In addition, the value of the nicotine reinforcement threshold in predicting tobacco use in real-world settings needs to be examined. The results of such studies will determine the potential utility of the estimated threshold for nicotine reinforcement in developing science-based tobacco control policies.

Smoke extracts and nicotine, but not tobacco extracts, potentiate firing and burst activity of ventral tegmental area dopaminergic neurons in mice

Nicotine prominently mediates the behavioral effects of tobacco consumption, either through smoking or when taking tobacco by snuff or chew. However, many studies question the exclusive role of nicotine in these effects. The use of preparations containing all the components of tobacco, such as tobacco and smoke extracts, may be more suitable than nicotine alone to investigate the behavioral effects of smoking and tobacco intake. In the present study, the electrophysiological effects of tobacco and smoke on ventral tegmental area dopaminergic (DA) neurons were examined in vivo in anesthetized wild-type (WT), β2-nicotinic acetylcholine receptor (nAChR) knockout (β2-/-), α4-/-, and α6-/- mice and compared with those of nicotine alone. In WT mice, smoke and nicotine had similar potentiating effects on DA cell activity, but the action of tobacco on neuronal firing was weak and often inhibitory. In particular, nicotine triggered strong bursting activity, whereas no bursting activity was observed after tobacco extract (ToE) administration. In β2-/- mice, nicotine or extract elicited no modification of the firing patterns of DA cells, indicating that extract acts predominantly through nAChRs. The differences between DA cell activation profiles induced by tobacco and nicotine alone observed in WT persisted in α6-/- mice but not in α4-/- mice. These results would suggest that tobacco has lower addiction-generating properties compared with either nicotine alone or smoke. The weak activation and prominent inhibition obtained with ToEs suggest that tobacco contains compounds that counteract some of the activating effects of nicotine and promote inhibition on DA cell acting through α4β2*-nAChRs. The nature of these compounds remains to be elucidated. It nevertheless confirms that nicotine is the main substance involved in the tobacco addiction-related activation of mesolimbic DA neurons.

An examination of NMDA receptor contribution to conditioned responding evoked by the conditional stimulus effects of nicotine

RATIONALE

Research using a drug discriminated goal-tracking (DGT) task showed that the N-methyl-D: -aspartate (NMDA) channel blocker MK-801 (dizocilpine) reduced the nicotine-evoked conditioned response (CR).

OBJECTIVES

Given the unknown mechanism of the effect, Experiment 1 replicated the MK-801 results and included tests with NMDA receptor ligands. Experiments 2a and 2b tested whether MK-801 pretreatment blocked DGT via a state-dependency effect.

METHODS

In Experiment 1, adult male Sprague-Dawley rats received intermittent access to liquid sucrose following nicotine (0.4 mg base/kg); no sucrose was delivered on intermixed saline sessions. Conditioning was indicated by increased anticipatory dipper entries (goal-tracking) on nicotine compared to saline sessions. Antagonism and/or substitution tests were conducted with MK-801, phencyclidine, CGP 39551, d-CPPene (SDZ EAA 494), Ro 25,6981, L-701,324, ACPC, and NMDA. In Experiment 2a, rats received nicotine and sucrose on every session-no intermixed saline sessions without sucrose. Tests combined MK-801 or the non-competitive nicotinic acetylcholine receptor antagonist, mecamylamine with either nicotine or saline. Experiment 2b had sucrose delivered on saline sessions and no sucrose on intermixed nicotine sessions followed by MK-801 antagonism tests of the saline CS.

RESULTS

MK-801 and phencyclidine dose-dependently attenuated the CR in Experiment 1. Ro-25,6981 enhanced the CR, but did not substitute for nicotine. Other ligands showed inconsistent effects. In Experiment 2a, MK-801 pretreatment reduced goal-tracking when given before nicotine and saline test sessions; mecamylamine pretreatment had no effect. In Experiment 2b, MK-801 dose-dependently attenuated the saline-evoked CR.

CONCLUSIONS

Combined, the results suggest that MK-801 blocks discriminated goal-tracking by virtue of state-changing properties.

Waterpipe Smoking And The DRD2/ANKK1 Genotype

BACKGROUND

Waterpipe smoking is increasingly a worldwide phenomenon. Few studies have been conducted on the epidemiology of waterpipe smoking behavior and its genetic determinants. A polymorphism (TaqI) in the 3' untranslated region of the dopamine receptor gene (DRD2), later localized to the neighboring ANKK1 gene, has been previously linked to cigarette smoking. Since all tobacco products share the ability of stimulating the dopaminergic reward system, variation in the DRD2 genotype might be associated with waterpipe smoking addiction.

AIM

This study aims to explore genetic variations in DRD2 gene and waterpipe smoking, motives and addiction in Egyptian rural males.

MATERIAL AND METHODS

The subjects (N=154) were selected from participants in a household smoking prevalence survey if they were adults, males, currently smoking waterpipe and not smoking cigarettes. Participants were interviewed about their smoking behaviors. Blood samples were genotyped by polymerase chain reaction (PCR). Subjects were subsequently classified as either the A1 (presence of at least one A1 allele) or A2 group (A2 homozygotes).

RESULTS

The prevalence of A1 genotype was 34.4 % in current waterpipe users, and was associated with the maximum duration before smokers experienced craving to smoke: after adjusting for age of smoking initiation, smoking for addictive motives, and average daily tobacco consumption, the A1 carriers were more likely to experience craving within a shorter duration after abstinence (the first 24 hours) compared to subjects with A2/A2 genotype (Odds ratio [OR] 2.70, 95% confidence interval [CI]: 1.18 - 6.23). In addition, the frequent visitors of shisha cafes were more likely to be younger, heavy smokers and carriers of A1 allele (OR, 2.52, 95% CI: 1.06-6.02).

CONCLUSION AND RECOMMENDATIONS

This study revealed that the maximum duration before experiencing craving to smoke waterpipe and frequency of visiting cafés to smoke may be influenced by an inherited variations in the DRD2 genotype.

Subliminal processing of smoking-related and affective stimuli in tobacco addiction

Cognitive processing biases toward smoking-related and affective cues may play a role in tobacco dependence. Because processing biases may occur outside conscious awareness, the current study examined processing of smoking-related and affective stimuli presented at subliminal conditions. A pictorial subliminal repetition priming task was administered to three groups: (1) Nonsmokers (n = 56); (2) Smokers (> or =10 cigarettes/day) who had been deprived from smoking for 12 h (n = 47); and (3) Nondeprived smokers (n = 66). Prime stimuli were presented briefly (17 ms) and were followed by a mask (to render them unavailable to conscious awareness) and then a target. Participants were required to make a speeded classification to the target. A posttask awareness check was administered to ensure that participants could not consciously perceive the briefly presented primes (i.e., smoking paraphernalia, neutral office supplies, and happy, angry, and neutral facial expressions). The groups differed in the degree to which they exhibited a processing bias for smoking-related stimuli, F(2, 166) = 4.99, p = .008. Deprived smokers exhibited a bias toward processing smoking (vs. neutral office supply) stimuli, F(1, 46) = 5.67, p = .02, whereas nondeprived smokers and nonsmokers did not (ps > .22). The three groups did not differ in the degree to which they exhibited a subliminal processing bias for affective stimuli. Tobacco deprivation appears to increase smokers' subliminal processing of smoking-related (vs. neutral) stimuli but does not influence subliminal processing of affective stimuli. Future research should investigate whether subliminal biases toward smoking-related stimuli influence relapse.

Tobacco addiction

Tobacco use is associated with 5 million deaths per year worldwide and is regarded as one of the leading causes of premature death. Comprehensive programmes for tobacco control can substantially reduce the frequency of tobacco use. An important component of a comprehensive programme is the provision of treatment for tobacco addiction. Treatment involves targeting several aspects of addiction including the underlying neurobiology and behavioural processes. Furthermore, building an infrastructure in health systems that encourages and helps with cessation, as well as expansion of the accessibility of treatments, is necessary. Although pharmacological and behavioural treatments are effective in improving cessation success, the rate of relapse to smoking remains high, emphasising the strong addictive nature of nicotine. The future of treatment resides in improvement in patient matching to treatment, combination or novel drugs, and viewing nicotine addiction as a chronic disorder that might need long-term treatment.