Nicotine addiction

Anxiety symptoms and anxiety sensitivity in relation to cigarette dependence, perceived barriers for smoking cessation and quit problems among adult Latinx smokers

Cigarette smoking is associated with adverse physical and mental health among Latinx adults in the United States. The present investigation sought to explore the main and interactive effects of anxiety symptoms and anxiety sensitivity in relation to cigarette dependence, perceived barriers for smoking cessation, and severity of problems experienced when quitting among adult Latinx smokers. Participants included 338 Latinx adult daily cigarette smokers (Mage = 35.53 years; SD = 8.65; age range 18-61; 37.3% female). Results indicated that anxiety symptoms were associated with greater cigarette dependence, severity of problems when quitting, and perceived barriers for smoking cessation (effect size range: 2%-3% of variance), whereas anxiety sensitivity was related to severity of problems when quitting and perceived barriers for smoking cessation (effect size range: 2%-3% of variance). There was also a statistically significant interaction between anxiety sensitivity and anxiety symptoms for cigarette dependence; anxiety was related to cigarette dependence for Latinx smokers with higher levels of anxiety sensitivity, but not for those with lower levels of anxiety sensitivity. Overall, the present findings indicate that anxiety symptoms and anxiety sensitivity are relevant factors for better understanding cigarette dependence, problems experienced when trying to quit, and perceptions of barriers to quitting among adult Latinx smokers.

Evaluating Alcohol Use Severity in Terms of Cigarette Smoking-Related Processes and Anxiety/Depression Among Adult Latinx Smokers

OBJECTIVE

Although empirical work focused on smoking-drinking comorbidity among Latinx persons is growing, no work has explored the relation between alcohol use severity in terms of co-occurring smoking processes and mental health. Therefore, the present investigation aimed to explore the prevalence and role of alcohol use severity in relation to clinically significant tobacco and mental health problems among English-speaking Latinx adults who smoke cigarettes.

METHODS

Participants included 338 English-speaking Latinx adults who smoked cigarettes daily (Mage = 35.5 years; SD = 8.65; age range 18-61; 37.3% female).

RESULTS

Results indicated that approximately 68% of male and 61% of female smokers scored above established clinical cutoffs for hazardous and harmful alcohol use and possible alcohol dependence. Moreover, alcohol use severity was associated with increased risk for cigarette dependence, perceived barriers for quitting, and more problematic symptoms when trying to quit. Alcohol use severity was also related to more severe anxiety and depressive symptoms.

CONCLUSIONS

Overall, the current findings suggest that intervening to reduce alcohol use severity may be important to improving smoking cessation and mental health among Latinx persons who smoke.

Alcohol use severity in relation to pain severity and interference among latinx adults with current pain who smoke cigarettes

Limited research has focused expressly on dual tobacco-alcohol use among the Latinx population. Latinx individuals who smoke represent a tobacco health disparities group and evince elevated rates of pain problems and symptoms. Prior research has consistently linked pain problems and severity to smoking and alcohol prevalence, maintenance, and behavior. Accordingly, the current study sought to build from the limited work that exists among Latinx persons who smoke and evaluate the role of alcohol use severity in terms of pain severity and interference. The current sample consisted of 228 adult Latinx daily cigarette smokers (Mage = 34.95 years; SD = 8.58; 39.0% female) who endorsed current pain. Results indicated that elevated alcohol use problems were associated with greater levels of pain severity (R2 = 0.06) and interference (R2 = 0.06). The present findings suggest that there may be utility in clinical screening for alcohol use problems among Latinx persons who smoke to offset pain problems among this high-risk group.

Changes in Sales of Tobacco and Nicotine Replacement Therapy Products Before and During the COVID-19 Pandemic

INTRODUCTION

The COVID-19 pandemic and its associated social distancing policies such as lockdowns and quarantine influenced people's lives and health behaviors. We comprehensively assessed national trends in sales of cigarettes, cigars, e-cigarettes, and over-the-counter nicotine replacement therapy (NRT) products before and during the pandemic, allowing for cross-product comparisons. Stockpiling behavior was also assessed.

METHODS

We used US national tobacco and over-the-counter NRT retail store scanner data (excluding internet, specialty/vape store, and prescription sales) collected at 4-week intervals by NielsenIQ from December 2018 to June 2021. We applied an interrupted time-series model to assess differences in tobacco product and NRT unit sales before and during the pandemic. We defined the prepandemic period as December 16, 2018, through April 4, 2020, pandemic as starting on April 5, 2020, through June 26, 2021, and the stockpiling period as one 4-week period before the pandemic started.

RESULTS

Four-week cigarette, e-cigarette, and cigar unit sales on average increased by 11.5% (P = .006), 37.1% (P < .001), and 26.1% (P < .001) respectively, while 4-week NRT unit sales decreased on average by 13.1% (P < .001), during the pandemic compared with the prepandemic period. Stockpiling was associated with increases in sales of all tobacco products and NRT products.

CONCLUSION

Unit sales of assessed tobacco products increased while NRT unit sales decreased during the COVID-19 pandemic, compared with the prepandemic period. These changes may suggest an increase in the intensity of tobacco product use or stockpiling of tobacco products among people who use tobacco.

Perceived racial/ethnic discrimination in relation to smoking abstinence expectancies among adult Latinx smokers in the United States

INTRODUCTION

Hispanic/Latinx (hereafter Latinx) individuals in the United States (US) face unique smoking-related health disparities, including limited access to care and health insurance for smoking treatment. Social determinants of health (SDoH) have received increased recognition in their role of smoking behavior and cessation. However, research on SDoH in Latinx smoking populations has been limited. Past research on non-Latinx white individuals has found smoking abstinence expectancies to be an integral cognitive process related to multiple aspects of smoking behavior, and its role has also been understudied in Latinx individuals. Perceived racial/ethnic discrimination is one SDoH, but its role in relation to abstinence expectancies among Latinx smokers has not been explored. Therefore, the present investigation sought to evaluate perceived racial/ethnic discrimination in terms of smoking abstinence expectancies among Latinx smokers living in the US.

METHODS

Participants included 338 English-speaking Latinx adult daily cigarette smokers (M_age = 35.5 years; SD = 8.65; age range 18-61; 37.3 % female) recruited nationally throughout the US using Qualtrics Panels.

RESULTS

Results supported statistically significant main effects for perceived racial/ethnic discrimination in relation to increased smoking abstinence expectancies of negative mood, somatic symptoms, harmful consequences, and positive consequences (p's < 0.001).

DISCUSSION

Overall, the results of the present investigation build from a limited body of work on perceived racial/ethnic discrimination and smoking and provide novel evidence of consistent and moderate incremental associations between perceived racial/ethnic discrimination and negative and positive smoking abstinence expectancies among Latinx smokers.

Development of a Personalized Tobacco Cessation Intervention Package (PTCIP) for Persons with Schizophrenia in India

Background

Among persons with schizophrenia (PwS), tobacco use is higher in comparison to the general population, contributing to greater morbidity and mortality. Pharmacological interventions combined with psychosocial interventions are effective in tobacco cessation. While the effectiveness of extant psychosocial interventions-when used in isolation-seems limited, developing better combinations of interventions could help treatment providers deliver tobacco cessation services to PwS at different stages of motivation to quit. We aimed to develop a personalized tobacco cessation intervention package (PTCIP) for PwS.

Methods

The stage-based intervention package was developed through a systematic review of interventions for tobacco cessation, the authors' clinical experience, and expert validation. The components of the intervention package, developed for PwS visiting the outpatient psychiatric department, were retained, removed, or added based on the content validity ratio (CVR).

Results

The final components included brief advice, principles of motivational interviewing, psychoeducation, decisional balance matrix, positive reinforcement, offering various treatment options, personalized feedback using a smoking-risk calculator, and prediction of cardiovascular risk using the WHO package of essential noncommunicable disease (PEN). The delivery of the intervention package was refined based on pilot testing in eight participants.

Conclusion

The tailored package was designed to be delivered by a mental health professional as a single comprehensive 40 min to 45 min face-to-face session, integrated with routine follow-up visits, followed by two telephonic conversations in the second and third week of the initial session. The package needs to be tested in a randomized controlled trial for its effectiveness.

Perceived Racial/Ethnic Discrimination and Smoking Outcome Expectancies among Adult Latinx Smokers Living in the United States

Background: Smoking-related health disparities are prevalent in the Latinx community in the United States (US). Although Social Determinants of Health (SDoH) are known to contribute to a myriad of health problems among the Latinx population, there is relatively limited work expressly aimed at elucidating SDoH among Latinx smokers. Perceived racial/ethnic discrimination is one SDoH construct that may be especially relevant to understanding smoking-related cognition for Latinx smokers in the US. Smoking outcome expectancies, reflecting beliefs about the consequences of smoking, are established cognitive processes that have been linked to the maintenance and relapse of smoking. The purpose of the present work is to investigate perceived racial/ethnic discrimination in relation to smoking outcome expectancies amongst Latinx smokers in the US. Method: Participants included 338 English-speaking Latinx adult daily cigarette smokers from the US (Mage = 35.5 years; SD = 8.65; age range 18-61; 37.3% female). Results: Results indicated that perceived racial/ethnic discrimination was related to greater levels of negative reinforcement, positive reinforcement, and appetite-weight control expectancies, but not negative consequences expectancies. Discussion: Overall, the current findings provide novel insight into the relationship between perceived racial/ethnic discrimination and smoking outcome expectancies amongst English-speaking Latinx cigarette users in the US.

Subjective Changes in Tobacco Product Use among Korean Adults during the COVID-19 Pandemic

This study explored subjective changes in tobacco product use during the COVID-19 pandemic. The online survey included 828 tobacco product users and was implemented from 20 August to 27 August 2021. Participants were classified based on currently used products (cigarettes, heated tobacco products (HTPs), and e-cigarettes) and categorized as single, dual, or triple users. Subjective changes in product use over the past year were designated as “no chang”, “increase”, or “decreased”. Single use was most common, as reported by 447 participants (male 249, female 198), while 283 (male 164, female 119) and 98 (male 59, female 39) participants reported dual and triple use, respectively. Age, income, and triple use were associated with increased cigarette use, whereas living with family was associated with decreased use. Gender, age, income, and triple use were associated with the changed use of HTPs. No factors were significantly associated with an increase in e-cigarette use, whereas age and income were associated with decreased use. Similar to many COVID-19-related changes in cultural, social, and economic aspects of life, users’ patterns of tobacco product use have also changed. Increasing tobacco product taxes, effective messaging, and customized cessation services might help prevent or limit tobacco product usage.

Perceived stress and willingness to quit smoking among patients with depressive and anxiety disorders seeking treatment

RATIONALE AND OBJECTIVES

Little are known about nicotine dependence (ND), perceived stress, and willingness to quit smoking at different treatment stages in patient with affective disorders (AD). This study aimed to evaluate the association between ND and perceived stress among patients with AD presenting with psychiatric treatment at different clinical stages (first visit or follow-up), and in different nicotine type users (cigarette and waterpipe smokers). We also aimed to evaluate the willingness to quit smoking and its association with barriers to quitting.

METHODS

This cross-sectional mixed-method study collected quantitative and qualitative data from patients (n = 57) presenting for treatment with AD and ND at different sites in Saudi Arabia. Quantitative validated scales were used to assess the 70 of depression symptoms, anxiety symptoms, perceived stress, and ND. Qualitative questions assessed barriers to quit smoking. We used a linear regression modeling to estimate the association between ND and perceived stress as well as to estimate the association between barrier to quit and willingness to quit.

RESULTS

ND had a statistically significant association with perceived stress (odds ratio [OR]: 2.09; 95% confidence interval [CI]: 1.20-3.63). Participants in the follow-up group had a higher ND score than those in the first-visit group. One of the most commonly reported barriers to quitting was using nicotine as a stress management (33.3%), which predicted positive willingness to quit (OR: 2.23; 95% CI: 1.48-3.37; P < .01). Boredom was reported as a barrier in the waterpipe group more than cigarette group.

CONCLUSION

ND has a significant association with perceived stress regardless of treatment status in patients with AD, indicating the need to evaluate smoking cessation during the early stages of treatment for patients with AD and ND. It will be critical for clinicians to offer patients with AD alternative coping mechanisms to manage stress and boredom.

Biological determinants impact the neurovascular toxicity of nicotine and tobacco smoke: A pharmacokinetic and pharmacodynamics perspective

Accumulating evidence suggests that the detrimental effect of nicotine and tobacco smoke on the central nervous system (CNS) is caused by the neurotoxic role of nicotine on blood-brain barrier (BBB) permeability, nicotinic acetylcholine receptor expression, and the dopaminergic system. The ultimate consequence of these nicotine associated neurotoxicities can lead to cerebrovascular dysfunction, altered behavioral outcomes (hyperactivity and cognitive dysfunction) as well as future drug abuse and addiction. The severity of these detrimental effects can be associated with several biological determinants. Sex and age are two important biological determinants which can affect the pharmacokinetics and pharmacodynamics of several systemically available substances, including nicotine. With regard to sex, the availability of gonadal hormone is impacted by the pregnancy status and menstrual cycle resulting in altered metabolism rate of nicotine. Additionally, the observed lower smoking cessation rate in females compared to males is a consequence of differential effects of sex on pharmacokinetics and pharmacodynamics of nicotine. Similarly, age-dependent alterations in the pharmacokinetics and pharmacodynamics of nicotine have also been observed. One such example is related to severe vulnerability of adolescence towards addiction and long-term behavioral changes which may continue through adulthood. Considering the possible neurotoxic effects of nicotine on the central nervous system and the deterministic role of sex as well as age on these neurotoxic effects of smoking, it has become important to consider sex and age to study nicotine induced neurotoxicity and development of treatment strategies for combating possible harmful effects of nicotine. In the future, understanding the role of sex and age on the neurotoxic actions of nicotine can facilitate the individualization and optimization of treatment(s) to mitigate nicotine induced neurotoxicity as well as smoking cessation therapy. Unfortunately, however, no such comprehensive study is available which has considered both the sex- and age-dependent neurotoxicity of nicotine, as of today. Hence, the overreaching goal of this review article is to analyze and summarize the impact of sex and age on pharmacokinetics and pharmacodynamics of nicotine and possible neurotoxic consequences associated with nicotine in order to emphasize the importance of including these biological factors for such studies.

A systems omics-based approach to decode substance use disorders and neuroadaptations

Substance use disorders (SUDs) are a group of neuropsychiatric conditions manifesting due to excessive dependence on potential drugs of abuse such as psychostimulants, opioids including prescription opioids, alcohol, inhalants, etc. Experimental studies have generated enormous data in the area of SUDs, but outcomes from such data have remained largely fragmented. In this review, we attempt to coalesce these data points providing an important first step towards our understanding of the etiology of SUDs. We propose and describe a 'core addictome' pathway that behaves central to all SUDs. Besides, we also have made some notable observations paving way for several hypotheses; MECP2 behaves as a master switch during substance use; five distinct gene clusters were identified based on respective substance addiction; a central cluster of genes serves as a hub of the addiction pathway connecting all other substance addiction clusters. In addition to describing these findings, we have emphasized the importance of some candidate genes that are of substantial interest for further investigation and serve as high-value targets for translational efforts.

Nicotine e-cigarette vapor inhalation and self-administration in a rodent model: Sex- and nicotine delivery-specific effects on metabolism and behavior

E-cigarettes, which deliver vaporized nicotine, have dramatically risen in popularity in recent years, despite many unanswered questions about safety, efficacy in reducing dependence, and overall impact on public health. Other factors, such as sex, also play an important role in determining behavioral and neurochemical responses to drugs of abuse. In these studies, we sought to develop a protocol for vaporized e-cigarette nicotine self-administration in rats, as a foundation to better understand the differing effects of nicotine exposure routes on behavior and physiological function. We report a novel method that elicits robust nicotine vapor self-administration in male and female rats. Our findings indicate that 5-mg/ml nicotine vape solution provides a high level of consistency in lever-pressing behavior for both males and females. Moreover, in male rats, we find that such e-cigarette nicotine vapor induces similar blood levels of nicotine's main metabolite, cotinine, as that found with intravenous nicotine self-administration. Therefore, the breathing pattern during vapor exposure in males leads to similar levels of titrated nicotine intake as with intravenous nicotine self-administration. Interestingly, a differential effect was found in the females, in which the same conditions of vapor exposure led to decreased cotinine levels with vapor compared to intravenous self-administration. Finally, differences in nicotine-mediated locomotion provide further support of the physiological effects of e-cigarette vapor inhalation. Taken together, our findings reveal important sex differences in nicotine intake based on the route of exposure, and we further establish a protocol for nicotine vapor self-administration in rats.

E-cigarette vape and lung ACE2 expression: Implications for coronavirus vulnerability

Evidence in humans suggests a correlation between nicotine smoking and severe respiratory symptoms with COVID-19 infection. In lung tissue, angiotensin-converting enzyme 2 (ACE2) appears to mechanistically underlie viral entry. Here, we investigated whether e-cigarette vapor inhalation alters ACE2 and nicotinic acetylcholine receptor (nAChR) expression in male and female mice. In male lung, nicotine vapor inhalation induced a significant increase in ACE2 mRNA and protein, but surprisingly, these differences were not found in females. Further, both vehicle and nicotine vapor inhalation downregulated α5 nAChR subunits in both sexes, while differences were not found in α7 nAChR subunit expression. Finally, blood ACE2 levels did not differ with exposure, indicating that blood sampling is not a sufficient indicator of lung ACE2 changes. Together, these data indicate a direct link between e-cigarette vaping and increased ACE2 expression in male lung tissue, which thereby reveals an underlying mechanism of increased vulnerability to coronavirus infection in individuals vaping nicotine.

Pharmacogenetics factors influencing smoking cessation success; the importance of nicotine metabolism

Introduction: Smoking remains a worldwide epidemic, and despite an increase in public acceptance of the harms of tobacco use, it remains the leading cause of preventable death. It is estimated that up to 70% of all smokers express a desire to quit, but only 3-5% of them are successful.Areas covered: The goal of this review was to evaluate the current status of smoking cessation treatments and the feasibility of implementing personalized-medicine approaches to these pharmacotherapies. We evaluated the genetics associated with higher levels of nicotine addiction and follow with an analysis of the genetic variants that affect the nicotine metabolic ratio (NMR) and the FDA approved treatments for smoking cessation. We also highlighted the gaps in the process of translating current laboratory understanding into clinical practice, and the benefits of personalized treatment approaches for a successful smoking cessation strategy.Expert opinion: Evidence supports the use of tailored therapies to ensure that the most efficient treatments are utilized in an individual's smoking cessation efforts. An understanding of the genetic effects on the efficacy of individualized smoking cessation pharmacotherapies is key to smoking cessation, ideally utilizing a polygenetic risk score that considers all genetic variation.

Validity and reliability of the Korean version of the Wisconsin Smoking Withdrawal Scale

BACKGROUND/AIMS

This study evaluated the validity and reliability of the Korean version of the Wisconsin Smoking Withdrawal Scale (WSWS-K) for use in clinical practice and research on Korean smokers.

METHODS

The Wisconsin Smoking Withdrawal Scale was translated into Korean and then back-translated into English. The authors reviewed the translation and back-translation and approved the final questionnaire draft. The validity and reliability of the WSWS-K were evaluated based on data collected from 300 participants. Construct validity was evaluated with a confirmatory factor analysis. Criterion-related validity was assessed by examining the relationships between the subscales of the WSWS-K and the matched items of the Korean version of the Minnesota Nicotine Withdrawal Scale (MNWS-K).

RESULTS

The participants were predominantly male (93.6%) and the mean age was 59.23 ± 15.19 years. The confirmatory factor analysis revealed that fit indices (namely, the goodness-of-fit index, adjusted goodness-of-fit index, comparative fit index, and the normed fit index) exceeded or approached 0.9. Cronbach's alpha for the entire scale was 0.87. The total score of the WSWS-K had a statistically significant positive correlation with that of the MNWS-K (Pearson's correlation coefficient, 0.768; p < 0.01). Additionally, we performed linear regression between the WSWS-K and MNWS-K scores after adjusting for age, gender, comorbidity, and smoking history. After this adjustment, the p value of the WSWS- K was < 0.001.

CONCLUSION

The WSWS-K had satisfactory validity and reliability. The WSWS- K can be used with acceptable validity and reliability in research and clinical evaluation of Korean smokers.

Pyridine alkaloids with activity in the central nervous system

This review discusses all pyridine alkaloids with CNS activity, their therapeutic potential, and the interesting array of sources whence they originate.

OpenVape: An Open-Source E-Cigarette Vapor Exposure Device for Rodents

The prevalence of “vaping” has recently seen significant increases in North America, especially in adolescents. However, the behavioral correlates of vaping are largely unexplored. The uptake of existing technologies meant for rodent vapor inhalation remains limited because of a lack of affordability and versatility (ability to be used with a variety of vaporizers). The OpenVape (OV) offers an open-source, low-cost solution that can be used in a variety of research contexts. Here, we present a specific use case, combining the OV apparatus with JUUL e-cigarettes. This apparatus consists of Arduino-operated vacuum pumps that deliver vapor directly from e-cigarettes to exposure chambers. The OV is easy to build and customize for any type of vaporizer (e.g., nicotine pod or tank; cannabis flower or concentrates). To test the OV, we performed biochemical verification and behavioral studies. The behavioral test (conditioned place preference, CPP) was conducted using adolescent and adult animals to assess developmental differences in the rewarding effects of nicotine vapor, as previously observed with injected nicotine. These findings demonstrate that even after brief exposures to nicotine vapor, pharmacologically relevant nicotine and cotinine levels could be detected in plasma, and significant CPP was observed, especially in adolescent rats which showed preference at shorter puff delivery durations (lower nicotine doses) compared with adults. Together, these findings suggest that OV provides an affordable, open-source option for preclinical behavioral research into the effects of vaping.

Glial cells as therapeutic targets for smoking cessation

Smoking remains the leading cause of morbidity and mortality in the United States, with less than 5% of smokers attempting to quit succeeding. This low smoking cessation success rate is thought to be due to the long-term adaptations and alterations in synaptic plasticity that occur following chronic nicotine exposure and withdrawal. Glial cells have recently emerged as active players in the development of dependence phenotypes due to their roles in modulating neuronal functions and synaptic plasticity. Fundamental studies have demonstrated that microglia and astrocytes are crucial for synapse formation and elimination in the developing brain, likely contributing to why glial dysfunction is implicated in numerous neurological and psychiatric disorders. Recently, there is increasing evidence for the involvement of glial cells in drug dependence and its associated behavioral manifestations. This review summarizes the newly evaluated role of microglia and astrocytes as molecular drivers of nicotine dependence and withdrawal phenotypes. This article is part of the special issue on 'Contemporary Advances in Nicotine Neuropharmacology.

Implications of insular cortex laterality for treatment of nicotine addiction

BACKGROUND

Damage to the insula disrupts nicotine-induced cravings and is associated with greater odds of cessation. The role of laterality in regulating these changes is unclear. Neuroimaging studies in cigarette smokers show left hemispheric activation during a period of forced withdrawal and right hemispheric activation after having just smoked. Among current smokers hospitalized for stroke involving their insula, we compared left versus right insular damage and its effect on smoking outcomes.

METHODS

A total of 37 smokers hospitalized with unilateral insular strokes (14 right, 23 left) were administered questionnaires to assess urge (Questionnaire on Smoking Urges) before (retrospectively) and during hospitalization and 3 months post-stroke, withdrawal during hospitalization (Wisconsin Smoking Withdrawal Scale), and prolonged abstinence at 3 months post-stroke. Crude and adjusted linear regression models were performed controlling for baseline covariates.

RESULTS

Right and left insular-damaged smokers experienced a significant decrease in urge from baseline to hospitalization and three-month follow-up (p < 0.01). Smokers with left-sided insular infarcts relative to right-sided experienced a larger decrease in acute urge (adjusted β=-1.16, 95% CI: -2.59, 0.27, p = 0.11) but not chronically (adjusted β=-0.06, 95% CI: -1.53, 1.40, p = 0.93). Left-sided insular damage was also associated with significantly fewer and less severe withdrawal symptoms during hospitalization (adjusted β=-3.52, 95% CI: -7.01, -0.04, p = 0.05). No differences were noted between groups for prolonged abstinence (p = 0.50).

CONCLUSIONS

Left insular adaptations are suggestive to have an impact on acute changes in urge and withdrawal more so than the right insula, however lateral asymmetries did not exist for long-term changes.

Sensitization-dependent nicotine place preference in the adult zebrafish

Sensitization of motor activity is a behavioural test to evaluate the effects of psychostimulants. Conditioned place preference (CPP) is an associative learning procedure to examine the rewarding properties of drugs. We aimed to assess whether motor sensitization to drugs of abuse can make zebrafish more vulnerable to establishing drug-induced CPP. We first evaluated sensitization of locomotor activity of zebrafish to repeated administrations of nicotine and cocaine during 5 days and after 5 days of withdrawal. After withdrawal, when zebrafish were re-exposed to the same dose of nicotine or cocaine locomotor activity was increased by 103% and 166%, respectively. Different groups of zebrafish were sensitized to nicotine or cocaine and trained on a nicotine-CPP task the day after withdrawal. The nicotine dose selected for sensitization was not effective for developing CPP in naïve zebrafish whereas it elicited CPP in zebrafish that were previously sensitized to nicotine or cocaine. Levels of nicotinic acetylcholine receptor β₂, α₆ and α₇ subunit, Pitx3, and tyrosine hydroxylase 1 (TH1) mRNAs were increased in the brain of nicotine- and cocaine-sensitized zebrafish. Nicotine-CPP performed with drug-sensitized zebrafish provoked further enhancements in the expression of α₆ and α₇ subunit, Pitx3, and TH1 mRNAs suggesting that the expression of these molecules in the reward pathway is involved in both processes. Our findings indicate that repeated exposures to low doses of drugs of abuse can increase subject's sensitivity to the rewarding properties of the same or different drugs. This further suggests that casual drug intake increases the probability of becoming addict.

Crucial Role of Dopamine D2 Receptor Signaling in Nicotine-Induced Conditioned Place Preference

Nicotine in tobacco causes psychological dependence through its rewarding effect in the central nervous system (CNS). Although nicotine dependence is explained by dopamine receptor (DR) signaling together with nicotinic acetylcholine receptors (nAChRs), the synaptic molecular mechanism underlying the interaction between dopamine receptor and nAChRs remains unclear. Since reward signaling is mediated by dopamine receptors, we hypothesized that the dopamine D2 receptor (D2R), in part, mediates the synaptic modulation of nicotine-induced conditioned place preference (CPP) in addition to dopamine D1 receptor. To investigate the involvement of D2R, wild-type (WT) and dopamine D2 receptor knockout (D2RKO) mice were assessed using the CPP task after induction of nicotine-induced CPP. As expected, D2RKO mice failed to induce CPP behaviors after repeated nicotine administration (0.5 mg/kg). When kinase signaling was assessed in the nucleus accumbens and hippocampal CA1 region after repeated nicotine administration, both Ca²⁺/calmodulin-dependent protein kinase (CaMKII) and extracellular signal-regulated kinase (ERK) were upregulated in WT mice but not in D2RKO mice. Likewise, nicotine-induced CPP was associated with elevation of pro- brain-derived neurotropic factor (BDNF) and BDNF protein levels in WT mice, but not in D2RKO mice. Taken together, in addition to dopamine D1 receptor signaling, dopamine D2 receptor signaling is critical for induction of nicotine-induced CPP in mice.

Impact of smoking on thyroid gland: dose-related effect of urinary cotinine levels on thyroid function and thyroid autoimmunity

Cigarette smoking is believed to affect thyroid function and autoimmune thyroid disease. However, there is little information to analyze their association using objective biomarkers. The aim of this study was to investigate the dose-related effect of smoking on thyroid hormones and thyroid peroxidase antibody (TPO Ab) using urinary cotinine levels and a population-based cohort. The present study used the thyroid hormone and urinary cotinine dataset from sixth Korean National Health and Nutrition Examination Survey in 2014 and 2015, and a total of 4249 participants were included. Dose-response relationships between thyroid hormone (free T4, TSH, and TPO Ab) and urinary cotinine levels were estimated using ANCOVA after adjustment for all variables (age, height, weight, alcohol, exercise, and log- transformed iodine in urine). Urinary cotinine level was negatively correlated with TSH. The estimated coefficients were −0.0711 in males and −0.0941 in females (p < 0.0001). TPO Ab titer was positively correlated with cotinine levels in males (p < 0.0001). Our findings indicated a significant dose-related effect of urinary cotinine level on thyroid function, and thyroid autoimmunity.

Rat brain CYP2D activity alters in vivo central oxycodone metabolism, levels and resulting analgesia

Oxycodone is metabolized by CYP2D to oxymorphone. Despite oxymorphone being a more potent opioid-receptor agonist, its contribution to oxycodone analgesia may be minor because of low peripheral production, low blood-brain barrier permeability and central nervous system efflux. CYP2D metabolism within the brain may contribute to variation in central oxycodone and oxymorphone levels, thereby affecting analgesia. Brain CYP2D expression and activity are subject to exogenous regulation; nicotine induces rat brain, but not liver, CYP2D consistent with higher brain CYP2D in smokers. We assessed the role of rat brain CYP2D in orally administered oxycodone metabolism (in vivo brain microdialysis) and analgesia (tail-flick test) by inhibiting brain CYP2D selectively with intracerebroventricular propranolol (mechanism-based inhibitor) and inducing brain CYP2D with nicotine. Inhibiting brain CYP2D increased brain oxycodone levels (1.8-fold; P < 0.03) and analgesia (1.5-fold AUC0-60 ; P < 0.001) after oxycodone, while inducing brain CYP2D increased brain oxymorphone levels (4.6-fold; P < 0.001) and decreased analgesia (0.8-fold; P < 0.02). Inhibiting the induced brain CYP2D reversed the change in oxycodone levels (1.2-fold; P > 0.1) and analgesia (1.1-fold; P > 0.3). Brain, but not plasma, metabolic ratios were affected by pre-treatments. Peak analgesia was inversely correlated with ex vivo brain (P < 0.003), but not hepatic (P > 0.9), CYP2D activity. Altering brain CYP2D did not affect analgesia from oral oxymorphone (P > 0.9 for AUC0-60 across all groups), which is not a CYP2D substrate. Thus, brain CYP2D metabolism alters local oxycodone levels and response, suggesting that people with increased brain CYP2D activity may have reduced oxycodone response. Factors that alter individual oxycodone response may be useful for optimizing treatment and minimizing abuse liability.

Tobacco biomarkers and genetic/epigenetic analysis to investigate ethnic/racial differences in lung cancer risk among smokers

The Multiethnic Cohort Study has demonstrated that African Americans and Native Hawaiians have a higher risk for lung cancer due to cigarette smoking than Whites while Latinos and Japanese Americans have a lower risk. These findings are consistent with other epidemiologic studies in the literature. In this review, we summarize tobacco carcinogen and toxicant biomarker studies and genetic analyses which partially explain these differences. As determined by measurement of total nicotine equivalents in urine, which account for about 85% of the nicotine dose, African Americans take up greater amounts of nicotine than Whites per cigarette while Japanese Americans take up less. There are corresponding differences in the uptake of tobacco smoke carcinogens such as tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, 1,3-butadiene, and other toxic volatiles. The lower nicotine uptake of Japanese Americans is clearly linked to the preponderance of low activity forms of the primary nicotine metabolizing enzyme CYP2A6 in this ethnic group, leading to more unchanged nicotine in the body and thus lower smoking intensity. But the relatively high risk of Native Hawaiians and the low risk of Latino smokers for lung cancer are not explained by these factors. The possible role of epigenetics in modifying lung cancer risk among smokers is also discussed here. The results of these published studies may lead to a better understanding of susceptibility factors for lung cancer in cigarette smokers thus potentially identifying biomarkers that can detect those individuals at highest risk so that preventive approaches can be initiated at an early stage of the lung cancer development process.

Effects of aging on the effectiveness of smoking cessation medication

BACKGROUND

Considering the pharmacokinetic and pharmacodynamic aspects of different medications, it is plausible that the age of a smoker could affect the half-life of these drugs. The aim of this study was to compare the effectiveness of smoking cessation drugs (nicotine replacement therapy, bupropion, and varenicline) used either in isolation or in combination in adults under and over 60 years of age.

METHODS

Data were collected from 940 Brazilian patients participating in a smoking cessation program. Participants were prescribed smoking cessation medication to be used for at least 12 weeks and were followed for 52 weeks.

RESULTS

Cessation rates were significantly different among younger and older participants who were using nicotine replacement therapy (NRT) alone. Being over 60 years of age was significantly associated with increased cessation success among those who used NRT alone (OR 2.34, 95% CI: 1.36 to 4.04, p = 0.002). The effectiveness of varenicline and bupropion were not significantly different according to age groups.

CONCLUSION

Using age as a predictor for tailoring smoking cessation drugs might potentially lead to a more individualized prescription of smoking cessation therapy. These results should be tested in randomized controlled trials.

Immediate and Sustained Decrease in Smoking Urges After Acute Insular Cortex Damage

INTRODUCTION

Smoking urges are fundamental aspects of nicotine dependence that contribute significantly to drug use and postquit relapse. Recent evidence has indicated that damage to the insular cortex disrupts smoking behaviors and claims to reduce urges associated with nicotine use, although tools that assess urge have yet to be used to validate these findings. We examined the effect of insular versus non-insular damage on urge using a well-accepted urge scale.

METHODS

This 3-month observational prospective cohort study consisted of 156 current smokers hospitalized for acute ischemic stroke (38 with insular infarctions, 118 with non-insular infarctions). During hospitalization, the Questionnaire of Smoking Urges (QSU)-brief was assessed retrospectively based on experiences before the stroke (baseline, T0), prospectively immediately following the stroke (T1) and once more via telephone at 3-month follow-up (T2), with higher scores indicating greater urge. Bivariate statistics and multivariable linear regression were used to evaluate differences in QSU-brief scores, relative to baseline, between exposure groups, controlling for age, baseline dependence, stroke severity, use of nicotine replacement, and damage to other mesocorticolimbic regions.

RESULTS

A greater reduction in QSU-brief score was seen in the insular group compared to the non-insular group from T0 to T1 (covariate-adjusted difference in means of -1.15, 95% CI: -1.85, -0.44) and similarly from T0 to T2 (covariate-adjusted difference in means of -0.93, 95% CI: -1.79, -0.07).

CONCLUSIONS

These findings confirm the potential role of the insula in regulating nicotine-induced urges and support the growing evidence of its novelty as a key target for smoking cessation interventions.

IMPLICATIONS

Human lesioning studies that evaluate the insula's involvement in maintaining nicotine addiction make inferences of the insula's role in decreasing urge, but do not use validated instruments that directly assess urges. This study corroborates prior findings using the continuous Questionnaire of Smoking Urges to quantify changes in urge from before lesion onset to immediate and 3-month follow-up time points.

Characterization and Genome Analysis of a Nicotine and Nicotinic Acid-Degrading Strain Pseudomonas putida JQ581 Isolated from Marine

The presence of nicotine and nicotinic acid (NA) in the marine environment has caused great harm to human health and the natural environment. Therefore, there is an urgent need to use efficient and economical methods to remove such pollutants from the environment. In this study, a nicotine and NA-degrading bacterium—strain JQ581—was isolated from sediment from the East China Sea and identified as a member of Pseudomonas putida based on morphology, physio-biochemical characteristics, and 16S rDNA gene analysis. The relationship between growth and nicotine/NA degradation suggested that strain JQ581 was a good candidate for applications in the bioaugmentation treatment of nicotine/NA contamination. The degradation intermediates of nicotine are pseudooxynicotine (PN) and 3-succinoyl-pyridine (SP) based on UV, high performance liquid chromatography, and liquid chromatography-mass spectrometry analyses. However, 6-hydroxy-3-succinoyl-pyridine (HSP) was not detected. NA degradation intermediates were identified as 6-hydroxynicotinic acid (6HNA). The whole genome of strain JQ581 was sequenced and analyzed. Genome sequence analysis revealed that strain JQ581 contained the gene clusters for nicotine and NA degradation. This is the first report where a marine-derived Pseudomonas strain had the ability to degrade nicotine and NA simultaneously.

iTRAQ proteomic analysis of the hippocampus in a rat model of nicotine-induced conditioned place preference

Repeated exposures to nicotine are known to result in persistent changes in proteins expression in addiction-related brain regions, such as the striatum, nucleus accumbens and prefrontal cortex, but the changes induced in the protein content of the hippocampus remain poorly studied. This study established a rat model of nicotine-induced conditioned place preference (CPP), and screened for proteins that were differentially expressed in the hippocampus of these rats using isobaric tags for relative and absolute quantitation labeling (iTRAQ) coupled with 2D-LC MS/MS. The nicotine-induced CPP was established by subcutaneously injecting rats with 0.2 mg/kg nicotine. Relative to the control (saline) group, the nicotine group showed 0.67- and 1.5-fold changes in 117 and 10 hippocampal proteins, respectively. These differentially expressed proteins are mainly involved in calcium-mediated signaling, neurotransmitter transport, GABAergic synapse function, long-term synaptic potentiation and nervous system development. Furthermore, RT-PCR was used to confirmed the results of the proteomic analysis. Our findings identify several proteins and cellular signaling pathways potentially involved in the molecular mechanisms in the hippocampus that underlie nicotine addiction. These results provide insights into the mechanisms of nicotine treatment in hippocampus.

Nicotine Metabolism and Smoking: Ethnic Differences in the Role of P450 2A6

Nicotine is the primary addictive agent in tobacco, and P450 2A6 (gene name: CYP2A6) is the primary catalyst of nicotine metabolism. It was proposed more than 20 years ago that individuals who metabolize nicotine poorly would smoke less, either fewer cigarettes per day or less intensely per cigarette, compared to smokers who metabolize nicotine more efficiently. These poor metabolizers would then be less likely to develop lung cancer due to their lower exposure to the many carcinogens delivered with nicotine in each puff of smoke. Numerous studies have reported that smokers who carry reduced activity or null CYP2A6 alleles do smoke less. Yet only in Asian populations, both Japanese and Chinese, which have a high prevalence of genetic variants, has a link between CYP2A6, smoking dose, and lung cancer been established. In other ethnic groups, it has been challenging to confirm a direct link between P450 2A6-mediated nicotine metabolism and the risk of lung cancer. This challenge is due in part to the difficulty in accurately quantifying smoking dose and accurately predicting or measuring P450 2A6-mediated nicotine metabolism. Biomarkers of nicotine metabolism and smoking exposure, including the ratio of trans-3-hydroxycotine to cotinine, a measure of P450 2A6 activity and plasma cotinine, or urinary total nicotine equivalents (the sum of nicotine and six metabolites) as measures of exposure are useful for addressing this challenge. However, to take full advantage of these biomarkers in the study of ethnic/racial differences in the risk of lung cancer requires the complete characterization of nicotine metabolism across ethnic/racial groups. Variation in metabolism pathways, other than those catalyzed by P450 2A6, can impact biomarkers of both nicotine metabolism and dose. This is clearly important for smokers with low levels of UGT2B10-catalyzed nicotine and cotinine glucuronidation because the UGT2B10 genotype influences plasma cotinine levels. Cotinine is not glucuronidated in 15% of African American smokers (compared to 1% of Whites) due to the prevalence of a UGT2B10 splice variant. This variant contributes significantly to the higher plasma cotinine levels per cigarette in this group and may also influence the accuracy of the 3HCOT to cotinine ratio as a measure of P450 2A6 activity.

Novel Association of Genetic Markers Affecting CYP2A6 Activity and Lung Cancer Risk

Metabolism of nicotine by cytochrome P450 2A6 (CYP2A6) is a suspected determinant of smoking dose and, consequently, lung cancer risk. We conducted a genome-wide association study (GWAS) of CYP2A6 activity, as measured by the urinary ratio of trans-3'-hydroxycotinine and its glucuronide conjugate over cotinine (total 3HCOT/COT), among 2,239 smokers in the Multiethnic Cohort (MEC) study. We identified 248 CYP2A6 variants associated with CYP2A6 activity (P < 5 × 10-8). CYP2A6 activity was correlated (r = 0.32; P < 0.0001) with total nicotine equivalents (a measure of nicotine uptake). When we examined the effect of these variants on lung cancer risk in the Transdisciplinary Research in Cancer of the Lung (TRICL) consortium GWAS dataset (13,479 cases and 43,218 controls), we found that the vast majority of these individual effects were directionally consistent and associated with an increased lung cancer risk. Two hundred and twenty-six of the 248 variants associated with CYP2A6 activity in the MEC were available in TRICL. Of them, 81% had directionally consistent risk estimates, and six were globally significantly associated with lung cancer. When conditioning on nine known functional variants and two deletions, the top two SNPs (rs56113850 in MEC and rs35755165 in TRICL) remained significantly associated with CYP2A6 activity in MEC and lung cancer in TRICL. The present data support the hypothesis that a greater CYP2A6 activity causes smokers to smoke more extensively and be exposed to higher levels of carcinogens, resulting in an increased risk for lung cancer. Although the variants identified in these studies may be used as risk prediction markers, the exact causal variants remain to be identified. Cancer Res; 76(19); 5768-76. ©2016 AACR.

The tobacco-using periodontal patient: role of the dental practitioner in tobacco cessation and periodontal disease management

Although the prevalence of tobacco use has declined in some parts of the world, tobacco use remains a persistent and, in some cases, growing problem that will continue to be a fundamental challenge facing dental practitioners in the decades ahead. Dental practitioners have a unique opportunity and professional obligation to be a positive influence in reducing the economic and social burden inflicted by tobacco use on dental and general health. In this article, the current noninvasive, evidence-based approaches are presented for dental practitioners to help patients avoid initiating tobacco use, to encourage and assist patients in ceasing tobacco use and to address tobacco-induced damage to periodontal supporting tissues.

Nicotine receptor partial agonists for smoking cessation

BACKGROUND

Nicotine receptor partial agonists may help people to stop smoking by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist).

OBJECTIVES

To review the efficacy of nicotine receptor partial agonists, including varenicline and cytisine, for smoking cessation.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's specialised register for trials, using the terms ('cytisine' or 'Tabex' or 'dianicline' or 'varenicline' or 'nicotine receptor partial agonist') in the title or abstract, or as keywords. The register is compiled from searches of MEDLINE, EMBASE, and PsycINFO using MeSH terms and free text to identify controlled trials of interventions for smoking cessation and prevention. We contacted authors of trial reports for additional information where necessary. The latest update of the specialised register was in May 2015, although we have included a few key trials published after this date. We also searched online clinical trials registers.

SELECTION CRITERIA

We included randomised controlled trials which compared the treatment drug with placebo. We also included comparisons with bupropion and nicotine patches where available. We excluded trials which did not report a minimum follow-up period of six months from start of treatment.

DATA COLLECTION AND ANALYSIS

We extracted data on the type of participants, the dose and duration of treatment, the outcome measures, the randomisation procedure, concealment of allocation, and completeness of follow-up.The main outcome measured was abstinence from smoking at longest follow-up. We used the most rigorous definition of abstinence, and preferred biochemically validated rates where they were reported. Where appropriate we pooled risk ratios (RRs), using the Mantel-Haenszel fixed-effect model.

MAIN RESULTS

Two trials of cytisine (937 people) found that more participants taking cytisine stopped smoking compared with placebo at longest follow-up, with a pooled risk ratio (RR) of 3.98 (95% confidence interval (CI) 2.01 to 7.87; low-quality evidence). One recent trial comparing cytisine with NRT in 1310 people found a benefit for cytisine at six months (RR 1.43, 95% CI 1.13 to 1.80).One trial of dianicline (602 people) failed to find evidence that it was effective (RR 1.20, 95% CI 0.82 to 1.75). This drug is no longer in development.We identified 39 trials that tested varenicline, 27 of which contributed to the primary analysis (varenicline versus placebo). Five of these trials also included a bupropion treatment arm. Eight trials compared varenicline with nicotine replacement therapy (NRT). Nine studies tested variations in varenicline dosage, and 13 tested usage in disease-specific subgroups of patients. The included studies covered 25,290 participants, 11,801 of whom used varenicline.The pooled RR for continuous or sustained abstinence at six months or longer for varenicline at standard dosage versus placebo was 2.24 (95% CI 2.06 to 2.43; 27 trials, 12,625 people; high-quality evidence). Varenicline at lower or variable doses was also shown to be effective, with an RR of 2.08 (95% CI 1.56 to 2.78; 4 trials, 1266 people). The pooled RR for varenicline versus bupropion at six months was 1.39 (95% CI 1.25 to 1.54; 5 trials, 5877 people; high-quality evidence). The RR for varenicline versus NRT for abstinence at 24 weeks was 1.25 (95% CI 1.14 to 1.37; 8 trials, 6264 people; moderate-quality evidence). Four trials which tested the use of varenicline beyond the 12-week standard regimen found the drug to be well-tolerated during long-term use. The number needed to treat with varenicline for an additional beneficial outcome, based on the weighted mean control rate, is 11 (95% CI 9 to 13). The most commonly reported adverse effect of varenicline was nausea, which was mostly at mild to moderate levels and usually subsided over time. Our analysis of reported serious adverse events occurring during or after active treatment suggests there may be a 25% increase in the chance of SAEs among people using varenicline (RR 1.25; 95% CI 1.04 to 1.49; 29 trials, 15,370 people; high-quality evidence). These events include comorbidities such as infections, cancers and injuries, and most were considered by the trialists to be unrelated to the treatments. There is also evidence of higher losses to follow-up in the control groups compared with the intervention groups, leading to a likely underascertainment of the true rate of SAEs among the controls. Early concerns about a possible association between varenicline and depressed mood, agitation, and suicidal behaviour or ideation led to the addition of a boxed warning to the labelling in 2008. However, subsequent observational cohort studies and meta-analyses have not confirmed these fears, and the findings of the EAGLES trial do not support a causal link between varenicline and neuropsychiatric disorders, including suicidal ideation and suicidal behaviour. The evidence is not conclusive, however, in people with past or current psychiatric disorders. Concerns have also been raised that varenicline may slightly increase cardiovascular events in people already at increased risk of those illnesses. Current evidence neither supports nor refutes such an association, but we await the findings of the CATS trial, which should establish whether or not this is a valid concern.

AUTHORS' CONCLUSIONS

Cytisine increases the chances of quitting, although absolute quit rates were modest in two recent trials. Varenicline at standard dose increased the chances of successful long-term smoking cessation between two- and three-fold compared with pharmacologically unassisted quit attempts. Lower dose regimens also conferred benefits for cessation, while reducing the incidence of adverse events. More participants quit successfully with varenicline than with bupropion or with NRT. Limited evidence suggests that varenicline may have a role to play in relapse prevention. The most frequently recorded adverse effect of varenicline is nausea, but mostly at mild to moderate levels and tending to subside over time. Early reports of possible links to suicidal ideation and behaviour have not been confirmed by current research.Future trials of cytisine may test extended regimens and more intensive behavioural support.

Cognitive Impairment Among the Aging Population in a Community in Southwest Nigeria

Background. Vascular risk models can be quite informative in assisting the clinician to make a prediction of an individual’s risk of cognitive impairment. Thus, a simple marker is a priority for low-capacity settings. This study examines the association of selected simple to deploy vascular markers with cognitive impairment in an elderly population. Method. This cross-sectional study assessed the cognitive functions of older persons 65 years and older in southwest Nigeria. Vascular parameters and risk factors were also measured. Analysis was done using SPSS, and logistic regression was used to explore the association between cognitive impairment and certain vascular risk factors such as elevated blood pressure, diabetes, and pulse pressure. Results. The study population comprised 623 participants (29.1% men) with mean age 73 ± 8.9 years. Having mean arterial pressure (MAP) and pulse pressure in the fourth quartiles (27% and 29.9%, respectively) was significantly associated with cognitive impairment ( p = .001, p < .001). Predicted cardiovascular risks of 10% or more was significantly associated with cognitive impairment ( p < .001). After adjusting for age, gender, educational level, and years of smoking, those with MAP in the fourth quartile were up to 3 times more likely to have cognitive impairment compared to those within the first quartile. Conclusion. Our study demonstrated that among elderly Nigerians, MAPs of 114 mmHg and more was an independent predictor of cognitive impairment. This is a simple measure that is available in low-capacity areas.

Understanding Inequalities of Maternal Smoking--Bridging the Gap with Adapted Intervention Strategies

Women who are generally part of socially disadvantaged and economically marginalized groups are especially susceptible to smoking during pregnancy but smoking rates are underreported in both research and interventions. While there is evidence to support the short-term efficacy of nicotine replacement therapy (NRT) use in pregnancy, long-term abstinence rates are modest. Current health strategies and interventions designed to diminish smoking in pregnancy have adopted a simplified approach to maternal smoking-one that suggests that they have a similar degree of choice to non-pregnant smokers regarding the avoidance of risk factors, and overlooks individual predictors of non-adherence. As a result, interventions have been ineffective among this high-risk group. For this reason, this paper addresses the multiple and interacting determinants that must be considered when developing and implementing effective strategies that lead to successful smoking cessation: socioeconomic status (SES), nicotine dependence, social support, culture, mental health, and health services. Based on our review of the literature, we conclude that tailoring cessation programs for pregnant smokers may ultimately optimize NRT efficacy and reduce the prevalence of maternal smoking.

Tobacco Use and Exposure to Second-Hand Smoke among Urban Residents: A Community-Based Investigation

Objectives: In 2005, China acceded to the World Health Organization Framework Convention on Tobacco Control (WHO FCTC), the foundation for the global fight against tobacco. Certain cities in China have established local regulations to control tobacco use ahead of national policy; however, without the enforcement of statutory law, some of these regulations are merely lip service. The aim of the study was to assess the effects of city policy on smoking prevalence and on second-hand smoke (SHS) exposure status among non-smokers in Changchun City. Methods: A cross-sectional survey covering a multiple-stage, representative sample of the urban population aged ≥15 years was conducted between 1 Dec 2013 and 31 Jan 2014. The WHO and the US Centers for Disease Control and Prevention developed the questionnaires used, which included demographic characteristics, smoking behaviors and SHS exposure status. Results: Overall cigarette smoking prevalence was 23.5%; daily cigarette smoking prevalence was 21.2%. Smoking prevalence and cigarettes consumed per day was higher among men (p < 0.05) and those aged 45–64 years (p < 0.05). Among current smokers, 8.1% planned to quit within 12 months; 53.4% had no intention of quitting. Overall SHS exposure prevalence was 41.9% (workplace) and 34.1% (at home) over the previous 30 days. The weighted workplace SHS exposure prevalence increased with age. Conclusions: The high proportion of smokers with no intention of quitting and the high level of SHS exposure may constitute one of the most significant barriers to successful smoking cessation in the city. A continued drive to promote full implementation of the WHO FCTC is still needed.

Smoking topography in Korean American and white men: preliminary findings

This is the first study of Korean Americans' smoking behavior using a topography device. Korean American men smoke at higher rates than the general U.S.

POPULATION

Korean American and White men were compared based on standard tobacco assessment and smoking topography measures. They smoked their preferred brand of cigarettes ad libitum with a portable smoking topography device for 24 h. Compared to White men (N = 26), Korean American men (N = 27) were more likely to smoke low nicotine-yield cigarettes (p < 0.001) and have lower Fagerstrom nicotine dependence scores (p = 0.04). Koreans smoked fewer cigarettes with the device (p = 0.01) than Whites. Controlling for the number of cigarettes smoked, Koreans smoked with higher average puff flows (p = 0.05), greater peak puff flows (p = 0.02), and shorter interpuff intervals (p < 0.001) than Whites. Puff counts, puff volumes, and puff durations did not differ between the two groups. This study offers preliminary insight into unique smoking patterns among Korean American men who are likely to smoke low nicotine-yield cigarettes. We found that Korean American men compensated their lower number and low nicotine-yield cigarettes by smoking with greater puff flows and shorter interpuff intervals than White men, which may suggest exposures to similar amounts of nicotine and harmful tobacco toxins by both groups. Clinicians will need to consider in identifying and treating smokers in a mutually aggressive manner, irrespective of cigarette type and number of cigarette smoked per day.

Nicotine Increases Codeine Analgesia Through the Induction of Brain CYP2D and Central Activation of Codeine to Morphine

CYP2D metabolically activates codeine to morphine, which is required for codeine analgesia. Permeability across the blood-brain barrier, and active efflux, suggests that initial morphine in the brain after codeine is due to brain CYP2D metabolism. Human CYP2D is higher in the brains, but not in the livers, of smokers and 7-day nicotine treatment induces rat brain, but not hepatic, CYP2D. The role of nicotine-induced rat brain CYP2D in the central metabolic activation of peripherally administered codeine and resulting analgesia was investigated. Rats received 7-day nicotine (1 mg/kg subcutaneously) and/or a single propranolol (CYP2D mechanism-based inhibitor; 20 μg intracerebroventricularly) pretreatment, and then were tested for analgesia and drug levels following codeine (20 mg/kg intraperitoneally) or morphine (3.5 mg/kg intraperitoneally), matched for peak analgesia. Nicotine increased codeine analgesia (1.59X AUC(0-30 min) vs vehicle; p<0.001), while propranolol decreased analgesia (0.56X; p<0.05); co-pretreatment was similar to vehicle controls (1.23X; p>0.1). Nicotine increased, while propranolol decreased, brain, but not plasma, morphine levels, and analgesia correlated with brain (p<0.02), but not plasma (p>0.4), morphine levels after codeine. Pretreatments did not alter baseline or morphine analgesia. Here we show that brain CYP2D alters drug response despite the presence of substantial first-pass metabolism of codeine and further that nicotine induction of brain CYP2D increases codeine response in vivo. Thus variation in brain CYP2D activity, due to genetics or environment, may contribute to individual differences in response to centrally acting substrates. Exposure to nicotine may increase central drug metabolism, not detected peripherally, contributing to altered drug efficacy, onset time, and/or abuse liability.

Pathways and networks-based analysis of candidate genes associated with nicotine addiction

Nicotine is the addictive substance in tobacco and it has a broad impact on both the central and peripheral nervous systems. Over the past decades, an increasing number of genes potentially involved in nicotine addiction have been identified by different technical approaches. However, the molecular mechanisms underlying nicotine addiction remain largely unclear. Under such situation, a comprehensive analysis focusing on the overall functional characteristics of these genes, as well as how they interact with each other will provide us valuable information to understand nicotine addiction. In this study, we presented a systematic analysis on nicotine addiction-related genes to identify the major underlying biological themes. Functional analysis revealed that biological processes and biochemical pathways related to neurodevelopment, immune system and metabolism were significantly enriched in the nicotine addiction-related genes. By extracting the nicotine addiction-specific subnetwork, a number of novel genes associated with addiction were identified. Moreover, we constructed a schematic molecular network for nicotine addiction via integrating the pathways and network, providing an intuitional view to understand the development of nicotine addiction. Pathway and network analysis indicated that the biological processes related to nicotine addiction were complex. Results from our work may have important implications for understanding the molecular mechanism underlying nicotine addiction.

Nicotine and health

Nicotine, an alkaloid derived from the leaves of tobacco plants (Nicotiana tabacum and Nicotiana rustica) is the primary addictive agent in tobacco products.(1,2) There are different ways of administering the various products including smoking cigarettes, chewing tobacco, holding moist snuff in the mouth, inhaling dry snuff through the nose, inhaling smoke from a waterpipe and inhaling vapour from an electronic cigarette.(3-6) It can be difficult differentiating the effects of nicotine from the many other toxic substances these products also contain. Here we review the pharmacological effects of nicotine but we will not review the well-known harmful effects of cigarettes, where it is primarily the toxins and carcinogens in tobacco smoke rather than the nicotine that cause illness and death.(7) A future article will consider the use of electronic cigarettes.

E-cigarettes: Are we renormalizing public smoking? Reversing five decades of tobacco control and revitalizing nicotine dependency in children and youth in Canada

An electronic cigarette (e-cigarette) is a battery attached to a chamber containing liquid that may (or may not) contain nicotine. The battery heats the liquid and converts it into a vapour, which is inhaled, mimicking tobacco smoking. The e-cigarette does not rely on tobacco as a source of nicotine but, rather, vaporizes a liquid for inhalation. E-liquids are often flavoured and may contain nicotine in various concentrations, although actual amounts are seldom accurately reflected in container labelling. The deleterious effects of nicotine on paediatric health are well established. The use of e-cigarettes in the paediatric age group is on the rise in Canada, as are associated nicotine poisonings. E-devices generate substantial amounts of fine particulate matter, toxins and heavy metals at levels that can exceed those observed for conventional cigarettes. Children and youth are particularly susceptible to these atomized products. Action must be taken before these devices become a more established public health hazard. Policies to denormalize tobacco smoking in society and historic reductions in tobacco consumption may be undermined by this new 'gateway' product to nicotine dependency.

Multigenerational and transgenerational inheritance of drug exposure: The effects of alcohol, opiates, cocaine, marijuana, and nicotine

Familial inheritance of drug abuse is composed of both genetic and environmental factors. Additionally, epigenetic transgenerational inheritance may provide a means by which parental drug use can influence several generations of offspring. Recent evidence suggests that parental drug exposure produces behavioral, biochemical, and neuroanatomical changes in future generations. The focus of this review is to discuss these multigenerational and transgenerational phenotypes in the offspring of animals exposed to drugs of abuse. Specifically, changes found following the administration of alcohol, opioids, cocaine, marijuana, and nicotine will be discussed. In addition, epigenetic modifications to the genome following administration of these drugs will be detailed as well as their potential for transmission to the next generation.

Smokers' strategic responses to sin taxes: evidence from panel data in Thailand

In addition to quitting and cutting consumption, smokers faced with higher cigarette prices may compensate in several ways that mute the health impact of cigarette taxes. This study examines three price avoidance strategies among adult male smokers in Thailand: trading down to a lower-priced brand, buying individual sticks of cigarettes instead of packs, and substituting roll-your-own tobacco for factory-manufactured cigarettes. Using two panels of microlevel data from the International Tobacco Control Southeast Asia Study, collected in 2005 and 2006, we estimate the effects of a substantial excise tax increase implemented throughout Thailand in December 2005. We present estimates of the marginal effects and price elasticities for each of five consumer behaviors. We find that, controlling for baseline smoking characteristics, sociodemographics, and policy variables, quitting is highly sensitive to changes in cigarette prices, but so are brand choice, stick-buying, and use of roll-your-own tobacco. Neglecting such strategic responses leads to overestimates of a sin tax's health impact, and neglecting product substitution distorts estimates of the price elasticity of cigarette demand. We discuss the implications for consumer welfare and several policies that mitigate the adverse impact of consumer responses.

A systematic review of health effects of electronic cigarettes

OBJECTIVE

To provide a systematic review of the existing literature on health consequences of vaporing of electronic cigarettes (ECs).

METHODS

Search in: PubMed, EMBASE and CINAHL.

INCLUSION CRITERIA

Original publications describing a health-related topic, published before 14 August 2014. PRISMA recommendations were followed. We identified 1101 studies; 271 relevant after screening; 94 eligible.

RESULTS

We included 76 studies investigating content of fluid/vapor of ECs, reports on adverse events and human and animal experimental studies. Serious methodological problems were identified. In 34% of the articles the authors had a conflict of interest. Studies found fine/ultrafine particles, harmful metals, carcinogenic tobacco-specific nitrosamines, volatile organic compounds, carcinogenic carbonyls (some in high but most in low/trace concentrations), cytotoxicity and changed gene expression. Of special concern are compounds not found in conventional cigarettes, e.g. propylene glycol. Experimental studies found increased airway resistance after short-term exposure. Reports on short-term adverse events were often flawed by selection bias.

CONCLUSIONS

Due to many methodological problems, severe conflicts of interest, the relatively few and often small studies, the inconsistencies and contradictions in results, and the lack of long-term follow-up no firm conclusions can be drawn on the safety of ECs. However, they can hardly be considered harmless.

Nicotine exposure beginning in adolescence enhances the acquisition of methamphetamine self-administration, but not methamphetamine-primed reinstatement in male rats

BACKGROUND

Nicotine is commonly abused in adolescence and is believed to be a "gateway" to other drugs of abuse [e.g., methamphetamine (METH)]. The relationship between early nicotine exposure and later METH use is complicated because the majority of juvenile smokers continue to use cigarettes into adulthood. Thus, the present investigation examined the individual and combined contribution of adolescent and adult nicotine exposure on METH self-administration.

METHODS

Forty-three male rats were pretreated with saline or nicotine (0.16 or 0.64 mg/kg, SC) from postnatal day (PD) 35-50. On PD 51, subjects were split into the following groups: SAL-SAL, 0.16-0.16, 0.16-SAL, 0.64-0.64, and 0.64-SAL. Rats were then trained to lever press for METH (0.05 mg/kg) for seven days on an FR1 and seven days on an FR3 reinforcement schedule. After acquisition training, rats underwent 14 days of extinction and were then tested for METH-induced primed reinstatement (1.0mg/kg, IP).

RESULTS

Data showed that rats receiving continuous injections of the low dose of nicotine (0.16-0.16) obtained more METH infusions versus the control group (SAL-SAL) on an FR1 and FR3 schedule. In addition, rats on the FR3 schedule that received a low dose of nicotine during the adolescent period only (0.16-SAL) had more METH intake than the control group (SAL-SAL). Interestingly, the high dose of nicotine exposure had no effect on METH intake and neither nicotine dose altered METH seeking behavior.

CONCLUSIONS

Low dose exposure to nicotine during adolescence enhances the reinforcing effects of METH, while heavier exposure has no effect on METH intake.

Nicotine exposure, blood pressure, and inflammation in tobacco smokers and chewers in a rural community in Nepal

Tobacco consumption is high amongst the people of Xxx. This study was carried out in 2011 in a rural community of Xxx, to compare pathological parameters associated with tobacco use in relation to nicotine metabolism between smokers, chewers, and a control group. A total of 216 volunteers provided blood and urine samples for testing nicotine metabolites, C-reactive protein, and cell counts. Data were analyzed using ANOVA, correlation, and t-tests using STATA. Differences in blood pressure amongst the groups indicate a role of smoking in preventing a rise in BP with age, likely attributable to a different mechanism of metabolism of tobacco constituents.

Involvement of neuronal β2 subunit-containing nicotinic acetylcholine receptors in nicotine reward and withdrawal: implications for pharmacotherapies

WHAT IS KNOWN AND OBJECTIVE

Tobacco smoking remains a major health problem. Nicotine binds to nicotinic acetylcholine receptors (nAChRs), which can cause addiction and withdrawal symptoms upon cessation of nicotine administration. Pharmacotherapies for nicotine addiction target brain alterations that underlie withdrawal symptoms. This review will delineate the involvement of the β2 subunit of neuronal nAChRs in nicotine reward and in generating withdrawal symptoms to better understand the efficacy of smoking cessation pharmacotherapies.

COMMENT

Chronic nicotine desensitizes and upregulates β2 subunit-containing nAChRs, and the prolonged upregulation of receptors may underlie symptoms of withdrawal. Experimental research has demonstrated that the β2 subunit of neuronal nAChRs is necessary for generating nicotine reward and withdrawal symptoms.

WHAT IS NEW AND CONCLUSION

Smoking cessation pharmacotherapies act on β2 subunit-containing nAChRs to reduce nicotine reward and withdrawal symptom severity.

Evaluation of the Psychometric Properties of the Malay Version of the Minnesota Nicotine Withdrawal Scale

OBJECTIVES

Assessment of nicotine withdrawal symptoms is an essential part of tobacco dependence treatment. This study aimed to evaluate the psychometric properties of a Malay translated version of the Minnesota Nicotine Withdrawal Scale (MNWS).

METHODS

The original scale was translated into Malay following the standard guidelines proposed for translation studies. The reliability and validity of the Malay version scale were evaluated on the basis of data collected from 133 participants. The Cronbach's alpha coefficient was calculated to assess the reliability. To validate the psychometric properties of the scale, factor analysis and construct validity were used. This study was conducted at the Quit Smoking Clinic at Penang General Hospital, Penang, Malaysia.

RESULTS

The translated scale has excellent reliability, with total Cronbach's alpha of 0.91. The test-retest reliability for the scale presented an excellent reliability and stability of the translated scale with Spearman's rank correlation coefficient (r = 0.876; P < 0.001). There was a significant positive correlation between the exhaled carbon monoxide level, Fagerstrom Test for Nicotine Dependence total score, and number of cigarettes smoked per day and the MNWS total score (r = 0.72, 0.68, and 0.68, respectively; P < 0.001). A principal-components analysis with orthogonal rotation yielded a unidimensional model that includes all the items of the MNWS.

CONCLUSIONS

The Malay version of the MNWS is a reliable and valid measure of withdrawal symptoms as well as the smoking urge, and it is applicable to clinical practice and research study.

Smoking and body fat mass in relation to bone mineral density and hip fracture: the Hordaland Health Study

Lower bone mineral density (BMD) in smokers may be attributable to lower body weight or fat mass, rather than to a direct effect of smoking. We analyzed the effects of smoking exposure, assessed by plasma cotinine, and body fat on BMD and the risk of subsequent hip fracture. In the community-based Hordaland Health Study (HUSK), 3003 participants 46-49 years and 2091 subjects 71-74 years were included. Cotinine was measured in plasma and information on health behaviors was obtained from self-administered questionnaires. BMD and total body soft tissue composition were measured by dual X-ray absorptiometry. Information on hip fracture was obtained from computerized records containing discharge diagnoses for hospitalizations between baseline examinations 1997-2000 through December 31st, 2009. In the whole cohort, moderate and heavy smokers had stronger positive associations between fat mass and BMD compared to never smokers (differences in regression coefficient (95% CI) per % change in fat mass = 1.38 (0.24, 2.52) and 1.29 (0.17, 2.4), respectively). In moderate and heavy smokers there was a nonlinear association between BMD and fat mass with a stronger positive association at low compared to high levels of fat mass (Davies segmented test, p<0.001). In elderly women and men, heavy smokers had an increased risk of hip fracture compared to never smokers (hazard ratio = 3.31, 95% CI: 2.05, 5.35; p<0.001). In heavy smokers there was a tendency of a lower risk of hip fracture with higher percentage of fat mass. The deleterious effect of smoking on bone health is stronger in lean smokers than in smokers with high fat mass.