Biomedical subjects

Wallace B Pickworth

Publications and source records attributed to Wallace B Pickworth.

At least 19 recordsLinked to original sources

PubMed2006

New lower nicotine cigarettes can produce compensatory smoking and increased carbon monoxide exposure.

Potential reduced exposure products (PREPs) are marketed as a means to reduce exposure to tobacco toxicants. Quest cigarettes, a new type of PREP, use genetically modified tobacco to provide a nicotine step-down approach, and are available as 0.6, 0.3 and 0.05 mg nicotine cigarettes. However, these cigarettes deliver equivalent levels of tar (10 mg). Prior research on low nicotine cigarettes suggests smokers will compensate for lower nicotine delivery by increasing their puffing behavior to extract more nicotine. This study tested the hypothesis that compensatory smoking will occur with this PREP as nicotine levels decrease, increasing exposure to tobacco toxins. Fifty smokers completed a within-subject human laboratory study investigating the effect of cigarette nicotine level on smoking behavior. Cigarette nicotine level was double-blinded and order of presentation counter-balanced. Breath carbon monoxide (CO) boost was used as a biomarker of smoke exposure; total puff volume to assess smoking behavior. Total puff volume was greatest for the 0.05 mg nicotine cigarette and CO boost was moderately greater after smoking the 0.3 and 0.05 mg cigarettes compared to the 0.6 mg nicotine cigarette. These data provide novel behavioral and biochemical evidence of compensatory smoking when smoking lower nicotine cigarettes. Although marketed as a PREP, increases in CO boost suggest this product can potentially be a harm-increasing product.

Adult↗

PubMed2006

Smoking rates and topography predict adolescent smoking cessation following treatment with nicotine replacement therapy.

Establishing measurement invariance of tobacco addiction among adolescents remains challenging. In adult smoking cessation trials, poor outcome is predicted by high cigarette consumption and large puff volume at baseline. We examined the predictive value of pretreatment smoking rates and topography variables for abstinence outcomes among 66 adolescents enrolled in a 3-month smoking cessation trial using nicotine replacement and cognitive behavioral therapy. Pretreatment variables included cigarettes per day (CPD), puff volume, puff duration, and several youth-adapted Fagerström-derived questionnaire scores. Outcome measures included prolonged abstinence at end of treatment and point-prevalent abstinence 3 months after the end of the trial. Logistic regression controlling for treatment group showed that increases in baseline CPD (odds ratio, 1.438; 95% confidence interval, 1.051-1.967) and average puff volume (odds ratio, 1.168; 95% confidence interval, 1.030-1.326) predicted continued smoking at the end of treatment. Puff volume (P=0.013), but not CPD, predicted abstinence at the 3-month follow-up. None of the youth-adapted Fagerström questionnaires predicted outcome on either abstinence measure. If confirmed in a larger sample, our findings suggest that puff topography, and possibly CPD, might predict cessation outcome better than Fagerström scores in adolescent smokers.

Administration, Cutaneous↗

PubMed2005

The effect of filter vent blocking and smoking topography on carbon monoxide levels in smokers.

Two studies were conducted to examine the effect of filter vent blocking and smoking topography on carbon monoxide (CO) levels in smokers. In Study 1, 12 participants smoked two types of cigarettes (Marlboro Light and Carlton 100) under two types of blocking conditions (unblocked and half-blocked) while using a smoking topography device. Participants were restricted to 8 puffs, separated by 45 s. Significant main effects of CO boost for cigarette type and blocking condition replicated previous findings. A significant increase in CO boost for the Marlboro Light blocked condition is a novel finding for this best-selling brand. That result and the finding that topography measures did not predict CO boost made us question the reliability of CO boost. In Study 2, we examined the reliability of CO boost by recruiting 12 participants to smoke three unblocked Carlton 100 cigarettes in one session and three half-blocked in another. CO boost was significantly greater for the blocked sessions compared to the unblocked and CO boost did not differ within session, thus supporting the reliability of the measure. When participants do not switch brands within a session, smoking topography measures are predictive of CO boost.

Adolescent↗

PubMed2005

Placebo cigarettes in a spaced smoking paradigm.

Existing evidence supports the notion that nicotine delivery and recentness of smoking mediate the effects of smoking, including decreases in tobacco craving. However, smoking placebo (denicotinized) cigarettes decreases tobacco craving after overnight abstinence. The present study tested whether the recentness of smoking was an important determinant in the ability of a placebo cigarette to reduce tobacco craving. Placebo (0.07 mg nicotine) and conventional (1.1 mg nicotine) cigarettes were used in a spaced smoking paradigm. In six experimental sessions lasting 240 min, subjects smoked either a placebo or conventional nicotine cigarette in intervals of either 30, 60, or 240 min. Heart rate (HR), exhaled carbon monoxide (CO) levels, and subjective (Schuh-Stitzer, QSU) measures of tobacco craving were obtained throughout the spaced smoking paradigm. HR and CO levels increased after smoking both types of cigarettes. Increasing the interval since the last cigarette significantly (p<0.001) increased the baseline values of tobacco craving. Smoking either the placebo or the conventional cigarette caused a significant (p<0.01) reduction in the craving score after smoking. However, the nicotine yield of the cigarette did not influence these patterns. It is concluded that acute tobacco cravings can be repeatedly diminished with cigarettes that do not deliver nicotine.

Adult↗

PubMed2005

Risk factors predicting changes in marijuana involvement in teenagers.

BACKGROUND: Marijuana use during adolescence has various adverse psychological and health outcomes. It is poorly understood whether the same risk factors influence different stages in the development of marijuana involvement. OBJECTIVE: To establish which risk factors best explain different stages of marijuana involvement. DESIGN: Data were collected at 2 points using computer-assisted personal interview (wave 1 and wave 2 were separated by 1 year). Twenty-one well-established risk factors of adolescent substance use/abuse were used to predict 5 stages of marijuana involvement: (1) initiation of experimental use, (2) initiation of regular use, (3) progression to regular use, (4) failure to discontinue experimental use, and (5) failure to discontinue regular use. Data were analyzed using logistic regression analysis. PARTICIPANTS: Middle school and high school students (N = 13 718, aged 11-21 years) participating in the National Longitudinal Study of Adolescent Health (Add Health). RESULTS: Three risk factors (own and peer involvement with substances, delinquency, and school problems) were the strongest predictors of all stages. Their combined presence greatly increased risk of initiation of experimental (odds ratio, 20) and regular (odds ratio, 87) marijuana use over the next year. Personality, family, religious, and pastime factors exerted stage-specific, sex-specific, and age-specific influences. CONCLUSIONS: Assessment of substance, school, and delinquency factors is important in identifying individuals at high risk for continued involvement with marijuana. Prevention and/or intervention efforts should focus on these areas of risk.

Adolescent↗

PubMed2005

Effects of different nicotine replacement therapies on postcessation psychological responses.

Transdermal nicotine patch (TN) and nicotine nasal spray (NS) are both efficacious forms of smoking cessation treatment, but have different pharmacokinetic properties and modes of action. To understand better psychological responses to treatment, we investigated the effects of TN versus NS on positive affect, negative affect, and withdrawal symptoms during treatment. Participants were randomly assigned to receive TN (n=172) or NS (n=163) plus seven sessions of behavioral counseling, and completed self-report questionnaires at pretreatment and during treatment. TN participants, but not NS participants, reported significant increases in positive affect during treatment. Increases in negative affect and withdrawal were observed, independent of treatment. Only changes in negative affect predicted relapse by the end of the treatment phase. These findings indicate that, although TN may enhance positive affect for smokers in treatment compared with NS, only changes in negative affect predict treatment outcome.

Administration, Cutaneous↗

PubMed2005

Safety and efficacy of the nicotine patch and gum for the treatment of adolescent tobacco addiction.

OBJECTIVES: To determine the safety and efficacy of the nicotine patch and gum for adolescents who want to quit smoking. DESIGN: Double-blind, double-dummy, randomized, 3-arm trial with a nicotine patch (21 mg), nicotine gum (2 and 4 mg), or a placebo patch and gum; all participants received cognitive-behavioral group therapy. SETTING: Inner-city, outpatient clinic on the East Coast. Subjects. Thirteen- to 17-year-old adolescents who smoked > or =10 cigarettes per day (CPD), scored > or =5 on the Fagerstrom Test of Nicotine Dependence, and were motivated to quit smoking. Intervention. Twelve weeks of nicotine patch or gum therapy with cognitive-behavioral therapy, with a follow-up visit at 6 months (3 months after the end of treatment). MAIN OUTCOME MEASURES: Safety assessed on the basis of adverse event reports for all 3 groups, prolonged abstinence, assessed through self-report and verified with exhaled carbon monoxide (CO) levels of < or =6 ppm, in intent-to-treat analyses, and smoking reduction (CPD and thiocyanate concentrations) among trial completers. RESULTS: A total of 120 participants were randomized (72% white, 70% female; age: 15.2 +/- 1.33 years; smoking: 18.8 +/- 8.56 CPD; Fagerstrom Test of Nicotine Dependence score: 7.04 +/- 1.29) from 1999 to 2003. Participants started smoking at 11.2 +/- 1.98 years of age and had been smoking daily for 2.66 +/- 1.56 years; 75% had at least 1 current psychiatric diagnosis. Mean compliance across groups was higher for the patch (mean: 78.4-82.8%) than for the gum (mean: 38.5-50.7%). Both the patch and gum were well tolerated, and adverse events were similar to those reported in adult trials. Changes in mean saliva cotinine concentrations throughout treatment were not statistically significant. Intent-to-treat analyses of all randomized participants showed CO-confirmed prolonged abstinence rates of 18% for the active-patch group, 6.5% for the active-gum group, and 2.5% for the placebo group; the difference between the active-patch and placebo arms was statistically significant. There was no significant effect of patch versus gum or gum versus placebo on cessation outcomes. Abstinence rates at the 3-month follow-up assessment were sustained but were not significantly associated with treatment group. Mean smoking rates, but not CO or thiocyanate concentrations, decreased significantly in all 3 arms but not as a function of treatment group. CONCLUSIONS: Nicotine patch therapy combined with cognitive-behavioral intervention was effective, compared with placebo, for treatment of tobacco dependence among adolescent smokers. Decreases in the numbers of cigarettes smoked appeared to be offset by compensatory smoking. Additional study of nicotine gum, with enhanced instructional support, is needed to assess its efficacy among adolescent smokers.

Administration, Cutaneous↗

PubMed2004

Olanzapine attenuates cue-elicited craving for tobacco.

RATIONALE: Recent biological conceptualizations of craving and addiction have implicated mesolimbic dopamine activity as a central feature of the process of addiction. Imaging, and pharmacological studies have supported a role for dopaminergic structures in cue-elicited craving for tobacco. OBJECTIVE: If mesolimbic dopamine activity is associated with cue-elicited craving for tobacco, a dopamine antagonist should attenuate cue-elicited craving for tobacco. Thus, the aim of the present study was to determine whether an atypical antipsychotic (olanzapine, 5 mg) decreased cue-elicited craving for tobacco. METHOD: Participants were randomly assigned to 5 days of pretreatment with olanzapine (5 mg; n=31) or were randomly assigned to 5 days of a matching placebo (n=28). Approximately 8 h after the last dose, participants were exposed to a control cue (pencil) followed by exposure to smoking cues. Participants subsequently smoked either nicotine cigarettes or de-nicotinized cigarettes. RESULTS: Olanzapine attenuated cue-elicited craving for tobacco but did not moderate the subjective effects of smoking. DISCUSSION: This study represents one of the first investigations of the effect of atypical antipsychotics on cue-elicited craving for tobacco. The results suggest that medications with similar profiles may reduce cue-elicited craving, which in turn, may partially explain recent observations that atypical antipsychotics may reduce substance use.

Adult↗

PubMed2004

History of marijuana use and tobacco smoking topography in tobacco-dependent adolescents.

Adolescent tobacco smokers have higher rates of marijuana (MJ) use than nonsmokers. Because MJ smoking typically involves deeper inhalation and longer breathholding than tobacco smoking, we hypothesized greater puff volume, longer puff duration and puff interval, and higher puff velocity during tobacco smoking among (1) MJ-using teens; (2) teens whose onset of MJ smoking occurred before tobacco (MBT). One hundred and three tobacco-dependent adolescents presented for smoking cessation treatment (66.0% female, 71.0% European American, mean age 15.3+/-1.25 years) smoked one cigarette of their own brand in the laboratory prior to study entry. Topography and associated physiological measures among current recreational (<5 days in a 14-day period) MJ users (n=25), current heavy (>/=5 days in a 14-day period) MJ users (n=22) and current non-MJ-smoking teens (n=56) were compared. There were no differences in tobacco smoking topography or physiological measures by recent MJ-smoking history or by order of substance initiation. Significantly more African American than European American adolescent smokers reported MJ use before tobacco. Our findings in adolescent smokers are consistent with results from adult studies in which history of MJ smoking was not associated with changes in tobacco smoking topography.

Adolescent↗

PubMed2004

Predictors of smoking development in a population-based sample of adolescents: a prospective study.

PURPOSE: To study the development of smoking behavior in adolescents using a longitudinal, multivariate design. METHODS: Adolescents (n = 14,133, age range 12 to 18 years) took part in the longitudinal Add Health study (two waves, separated by 1 year, 56% smokers and 44% nonsmokers at Wave 1). Eight risk factor domains were established at Wave 1 (daily activities, psychological health, personality, school situation, family functioning, rough living, religion, and neighborhood status), which were further separated into subdomains by factor analysis. Subdomains were used to predict risk at Wave 2 of smoking initiation, progression, or failure to discontinue, using logistic regression analysis. Analyses were performed for boys and girls separately and results corrected for age, race, urbanicity, and socioeconomic status. RESULTS: Use/abuse of other substances by self and peers influenced most stages of smoking, whereas trouble in school was associated with initiation and progression of smoking. Poor family relations predicted initiation of experimental smoking for girls, whereas low involvement in active pastimes predicted failure to discontinue experimental smoking. For boys, low religiosity predicted progression to regular smoking and failure to quit regular smoking, whereas delinquency also reduced success of regular smoking discontinuation. CONCLUSIONS: These findings may direct efforts for prevention and intervention of adolescent smoking behavior and may also provide guidance for future studies.

Adolescent↗

PubMed2004

A laboratory study of hydromorphone and cyclazocine on smoking behavior in residential polydrug users.

The effects of cyclazocine and hydromorphone on spontaneous and laboratory cigarette smoking were compared in a double-blind, placebo-controlled, crossover study. Participants (seven men, one woman) received oral doses of placebo, cyclazocine (0.2, 0.4, and 0.8 mg) and hydromorphone (5 and 15 mg) in a randomized order on experimental days. Spontaneous smoking was recorded during two intervals on the experimental days: a 3-h period 5-8 h after drug administration (Interval 1), and the rest of the day (Interval 2). Measures of smoking topography and subjective and physiologic effects of a single cigarette were obtained on the experimental days. Neither hydromorphone nor cyclazocine significantly changed spontaneous smoking when compared to the placebo condition; however, compared to hydromorphone (5 mg), cyclazocine (0.4 and 0.8 mg) decreased spontaneous smoking during Interval 1. Hydromorphone (5 and 15 mg) and cyclazocine (0.4 and 0.8 mg) diminished smoking-induced increases in heart rate. Compared to the placebo condition, cyclazocine (0.2 and 0.4 mg) reduced exhaled carbon monoxide (CO) boost, a measure of smoke exposure. Further studies of the effects of kappa opioid agonists on smoking behavior may lead to a better understanding of the role of opiates in smoking behavior.

Adult↗

PubMed2004

Smoking topography and trajectory of asthmatic adolescents requesting cessation treatment.

BACKGROUND: Teenage smokers cite health concerns as their primary motivators for tobacco smoking cessation. Smoke exposure aggravates the clinical course of asthma, yet few reports have examined the association between asthma and smoking topography and trajectory. METHODS: Before their enrollment in a smoking cessation trial, we assessed the smoking topography (i.e., puff volume, maximum puff velocity, puff duration, and interpuff interval) and smoking trajectory (i.e., age of first cigarette, age of daily smoking, time to treatment request, and prior quit attempts) in 30 self-reported asthmatic and 92 nonasthmatic tobacco-dependent teenagers (mean age, 15.2 +/- 1.3 years, 28.7% African-American). Approximately one-half of asthmatics used prescribed medications for their asthma. RESULTS: There was no significant difference in smoking topography or smoking trajectory variables between asthmatic and nonasthmatic adolescents, nor between medicated and nonmedicated asthma subgroups. CONCLUSIONS: Although tobacco smoking exacerbates asthmatic symptoms, these data suggest that age of smoking initiation, as well as smoking topography characteristics in asthmatic adolescents, does not differ from those of adolescents without asthma. These findings highlight the need for more effective health counseling of asthmatic youth regarding the physical and behavioral effects of smoking.

Adolescent↗

PubMed2004

Quantitative comparisons between a nicotine delivery device (Eclipse) and conventional cigarette smoking.

In 1997, R. J. Reynolds introduced Eclipse, a nicotine delivery device (NDD) purported to deliver lower levels of smoke than conventional cigarettes. This NDD uses a carbon fuel element to vaporize the nicotine in the rod; the user then inhales the nicotine vapor. In the present study, the effects of this NDD on smoking topography; substance delivery factors; and physiological, subjective, and biochemical markers of smoking were compared with commercial cigarettes (referred to as Own Brand). All smoking occurred ad lib with the cigarette or NDD hand-held (conventional) or held in a topography mouthpiece. A total of 10 adults (seven males) smoked on five occasions: NDD conventional, NDD topography, Own Brand conventional, Own Brand topography (twice). Sessions were separated by at least 24 hr. Measures were taken before and 2, 5, 10, 15, 30, and 60 min after smoking. The NDD took longer to smoke (366 s vs. 292 s), required more puffs (14.8 vs. 10.8), and caused a larger increase in exhaled carbon monoxide (CO; 7.3 ppm vs. 4.2 ppm) than Own Brand. However, venous plasma nicotine boost was significantly larger 2 min after smoking Own Brand as compared with the NDD (16.4 ng/ml vs. 10.7 ng/ml). Puff volume (90.7 ml vs. 63.0 ml) and puff velocity (81.6 ml/s vs. 58.2 ml/s) were greater after the NDD than Own Brand, whereas inter-puff interval and puff duration were similar. Subjects rated the NDD as less satisfying (5.2 vs. 9.8), less rewarding (9.5 vs. 14.3), and more aversive (5.0 vs. 3.1) than their own brand. The results of this study indicate that this NDD exposes the user to significant quantities of nicotine, CO, and possibly other harmful components of tobacco smoke. The findings further validate the use of a topography device as an effective instrument to quantify smoke exposure.

Adult↗

PubMed2004

Smoking topography predicts abstinence following treatment with nicotine replacement therapy.

OBJECTIVE: Smoking topography refers to how a person smokes a cigarette and includes measures of the number of puffs and puff volume, duration, and velocity. This study examined the relationship between smoking topography and abstinence from cigarettes following nicotine replacement therapy. A secondary objective was to determine the relationship of smoking topography to carbon monoxide (CO) exposure. METHOD: Participants (n = 113) smoked one of their preferred brands of cigarette through a smoking topography device prior to participating in an open-label trial of transdermal nicotine versus nicotine nasal spray. A subset of participants (n = 50) provided breath CO samples prior to and following smoking the cigarette. RESULTS: Mean V(max) [odds ratio (OR), 1.12; 95% confidence interval (95% CI), 1.02-1.24; P = 0.02], mean puff volume (OR, 0.95; 95% CI, 0.91-0.98; P = 0.01), mean interpuff interval (OR, 1.06; 95% CI, 1.00-1.11; P = 0.03), and cigarette type (full flavor versus light/ultralight; OR, 0.35; 95% CI, 0.14-0.89; P = 0.03) were significant predictors of abstinence in a model controlling for treatment group and nicotine dependence. Controlling for time since last cigarette and initial CO level, mean puff velocity (beta = 0.171; P = 0.01) was the only significant predictor of CO boost. CONCLUSION: These results suggest that smoking topography may be useful to predict abstinence after using nicotine replacement therapy and to assess harm from smoking.

Adult↗

PubMed2003

Clove cigarette smoking: biochemical, physiological, and subjective effects.

Alternative tobacco products such as clove (kreteks) and bidi cigarettes have become increasingly popular among US smokers. The nicotine content of a popular clove cigarette (Djarum Special) filler averaged 7.4 mg; conventional cigarettes contained 13.0 mg. However, smoke yields from standardized machine-smoking analysis indicated it delivered more nicotine, carbon monoxide (CO), and tar than conventional cigarettes. In a clinical study, nicotine delivery, physiologic, and subjective effects of the clove cigarette were compared to their own brand of cigarette in 10 adult smokers (7 males). Average time to smoke the clove cigarette (549 s) and number of puffs (15.1) were significantly greater than own brand (314 s and 9.4 puffs). Increases in venous plasma nicotine and exhaled CO after smoking the clove cigarette (17.4 ng/ml; 6 ppm) were similar to those after own brand (17.6 ng/ml; 4.5 ppm). Maximal changes in heart rate (HR), systolic, and diastolic blood pressures (BP) did not differ significantly between the clove and own brand of cigarette. Compared to their own brand of cigarette, the clove cigarette was rated as better tasting and being distinctly different. Our findings indicate that clove cigarettes deliver significant quantities of nicotine, CO, and presumably other toxic components of tobacco smoke. Taste satisfaction, aromatic odor, and novelty may contribute to their appeal to young smokers.

Adult↗

PubMed2003

EEG effects of conventional and denicotinized cigarettes in a spaced smoking paradigm.

Although there is a documented association between plasma nicotine levels and smoking behavior, recent studies indicate that denicotinized cigarettes reduced craving and symptoms of tobacco withdrawal. Denicotinized cigarettes (that deliver tar but insignificant amounts of nicotine) and conventional cigarettes were compared in a within-subject spaced smoking study. In six sessions, subjects (n=10) smoked denicotinized cigarettes or conventional cigarettes every 30, 60 or 240 min (8, 4 or 1 cigarette(s)). EEG effects of the last cigarette of each session were deduced by comparisons with EEG recordings collected before smoking. Conventional cigarettes increased spectral edge EEG frequency, decreased theta power and increased beta1 power. Denicotinized cigarettes decreased spectral frequency. The EEG effects of both cigarettes depended upon the recentness of smoking. The results indicate that nicotine delivery, recentness and the process of smoking importantly influence the EEG; other, non-nicotine components of tobacco smoke may also exert EEG effects.

Adult↗

PubMed2003

Smoking topography: reliability and validity in dependent smokers.

Data from two studies were analyzed to determine whether smoking through the mouthpiece of a topography unit yields consistent measures over time and to verify that smoking through a mouthpiece results in a similar degree of smoke exposure as conventional smoking. In both studies, subjects smoked their usual brand of cigarette ad libitum. In study A, subjects (n=7) smoked through a mouthpiece on 4 separate experimental days. In study B, subjects (n=10) smoked on 2 separate days: Once conventionally and once through a mouthpiece. In both studies, exhaled carbon monoxide (CO) and physiological effects (heart rate and blood pressure) were measured before and after smoking. In study B, plasma nicotine concentrations also were measured. In study A, puff volume, puff duration, interpuff interval, and maximum puff velocity averaged 30.8 ml,.9 s, 19.9 s, and 44.6 ml/s, respectively. Intraclass correlation coefficients computed for puff volume (0.66), puff duration (0.75), and maximum puff velocity (0.68) indicated that these measures showed good reliability. In study B, smoking through the mouthpiece yielded similar topographical (time to smoke and number of puffs per cigarette) measures as conventional smoking. Also similar were changes in biochemical values: Plasma nicotine (18.5 ng/ml vs. 25.5 ng/ml), exhaled CO (4.6 ppm vs. 5.1 ppm), and heart rate (8.6 beats/min vs. 7.4 beats/min) for conventional and topography mouthpiece smoking conditions, respectively. Topography measures did not differ significantly between the two studies. Overall, the data from these two small-sample studies suggest that smoking topography provides a valid and reliable index of conventional smoking and an indirect measure of smoke exposure.

Adult↗

PubMed2003

Cigarette smoking and cervical cancer: Part II: a geographic variability study.

Cigarette smoking is considered a causative factor in a variety of cancers. However, the role of smoking in cervical cancer is disputed, in part because women who smoke may have other risk factors for cervical cancer, particularly HPV infection. We reviewed cigarette smoking prevalence, cervical and lung cancer incidence, and gross domestic product (GDP) per capita in the US and 73 other countries. It appears that smoking may play a prominent role in cervical cancer in developing countries, but less of a role in other countries.

Female↗