Case report: Cutaneous pseudolymphoma caused by a Leishmania infantum infection in a patient treated with anti-TNF antibody for plaque psoriasis.

For psoriasis, which affects up to 2% of the population and adalimumab is approved from the age of 4 years. Here, we present a middle-aged Italian man with long-term history of plaque psoriasis and psoriasis arthropathica and adalimumab therapy. He developed ulcers or nodules within the psoriatic plaques, resembling cutaneous infection with Leishmania infantum. TNF and other cytokines such as IL-12 and IFN-γ are central in the early control of the infection. Discontinuation of the anti-TNF-treatment resolved the infection without specific therapy.

Case Report: Diagnostic and Therapeutic Challenges in Severe Mechanobullous Epidermolysis Bullosa Acquisita.

Collagen VII is the main constituent of the anchoring fibrils, important adhesive structures that attach the epidermis to the dermal extracellular matrix. Two disorders are caused by dysfunction of collagen VII, both characterized by skin and mucosa fragility, epidermolysis bullosa acquisita (EBA) and dystrophic epidermolysis bullosa (DEB). EBA and DEB share high clinical similarities with significant difference in patients' age of onset and pathogenesis. Our patients presented with severe and recalcitrant mechanobullous EBA with characteristic DIF, IIF and ELISA diagnostics. But in both women recessive COL7A1 variants were also found, in a monoallelic state. Collagen VII from EBA keratinocytes of our cases was significantly more vulnerable to proteolytic degradation than control keratinocytes, hinting that the heterozygous pathogenic variants were sufficient to destabilize the molecule in vitro. Thus, even if the amount and functionality of mutant and normal type VII collagen polypeptides is sufficient to assure dermal-epidermal adhesion in healthy individuals, the functionally-impaired proteins are probably more prone to development of autoantibodies against them. Our work suggests that testing for COL7A1 genetic variants should be considered in patients with EBA, which either have a patient history hinting towards underlying dystrophic epidermolysis bullosa or pose therapeutic challenges.

Ecological momentary assessment of temptations and lapses in non-daily smokers.

RATIONALE: Little is known about relapse among non-daily, intermittent smokers (ITS), who have difficulty quitting, despite a lack of dependence. OBJECTIVES: To analyze situations associated with temptations to smoke and smoking lapses among ITS trying to maintain abstinence. METHODS: Participants were 130 initially abstinent ITS in the placebo arm of a smoking cessation study. EMA data captured participants' situations and states in temptations (n = 976), including those that eventuated in lapses (n = 147), for up to 6 weeks. Randomly timed assessments assessed background states (n = 11,446). Participants also reported coping performed to prevent lapses. Multilevel analyses compared temptations to background situations, and lapse episodes to resolved temptations. RESULTS: Temptations were marked by exposure to smoking cues, including others smoking, lax smoking restrictions, and alcohol consumption, as well as more negative affect. Lapses did not differ from resolved temptations in craving intensity, but were more often associated with smoking cues and availability of cigarettes, alcohol consumption, and worse affect, and were more often attributed to good moods. Both behavioral and cognitive coping responses were associated with avoiding lapsing, but behavioral coping had much larger effects. The effects of affective distress on lapse risk were mediated by its effects on coping. CONCLUSIONS: Smoking cues play a major role in ITS' temptations and lapses, perhaps indicating a degree of behavioral dependence. Affective distress also played a role in ITS lapses, undermining the idea that the affective distress seen in daily smokers' lapses is due to nicotine withdrawal. The data reinforce the important role of coping in preventing lapses.

Effectiveness of nicotine gum in preventing lapses in the face of temptation to smoke among non-daily smokers: a secondary analysis.

BACKGROUND AND AIMS: Non-daily smokers (NDS) comprise a large fraction of US smokers. Despite little or no dependence, as typically assessed, intermittent smokers (ITS) have difficulty quitting smoking. A randomized clinical trial comparing the effect of nicotine gum with placebo on quitting smoking in non-daily smokers did not find an effect on overall abstinence. We undertook an analysis to assess whether using nicotine gum versus placebo when tempted to smoke could reduce incidence of lapses in those situations. DESIGN: Within a 6-week randomized, placebo-controlled clinical trial of nicotine gum, analyses contrasted the outcome of temptation episodes where gum was or was not used. SETTING: Smoking cessation research clinic in Pittsburgh, PA, USA. PARTICIPANTS: A total of 255 adult ITS (131 nicotine gum, 124 placebo) seeking help for smoking cessation. INTERVENTION: Nicotine gum (2 mg) versus placebo for up to 8 weeks, with as-needed dosing instructions. MEASUREMENTS: Outcome was lapsing in temptation episodes, as reported by participants via ecological momentary assessment (EMA). Propensity scores predicting gum use from situational factors (e.g. mood, social setting, smoking cues) served as a control variable. FINDINGS: Participants reported 2713 temptation episodes, 46.0% (1248) of which resulted in smoking (lapsing). There was a significant gum use × active treatment interaction (P = 0.0009). Using nicotine gum decreased the odds of lapsing by 55% compared with using placebo [odds ratio (OR) = 0.45; 0.22-0.94]; when gum was not used, the assigned gum condition made no significant difference (OR = 1.53; 0.78-3.01; Bayes factor = 0.14). The nicotine effect was not reliably different when participants were trying to achieve abstinence versus when trying to maintain abstinence (OR = 0.44; 0.10, 2.03; P = 0.294; Bayes factor = 0.11), for men and women (OR = 1.68; 0.58, 4.87; P = 0.343; Bayes factor = 0.10), or for participants with some or no dependence (OR = 0.88; 0.30, 2.59; P = 0.811; Bayes factor = 0.06). CONCLUSIONS: When used in response to temptation to smoke, 2 mg nicotine gum can help to prevent lapses among non-daily smokers.

Using Nicotine Gum to Assist Nondaily Smokers in Quitting: A Randomized Clinical Trial.

INTRODUCTION: Non-daily intermittent smokers (ITS) comprise 30% of US adult smokers. ITS smoke for nicotine and have trouble quitting, but tend to smoke in particular situations. This study tested the effect of nicotine gum, used to prevent or react to situational temptations, for helping ITS quit. METHODS: ITS (smoking 4-27 days/month) seeking help quitting were randomized to 2 mg nicotine gum (n = 181) or placebo (n = 188), to be used to anticipate or react to temptations to smoke, for 8 weeks. Participants received up to six sessions of behavioral counseling. The primary outcome was 6-month biochemically verified continuous abstinence; analyses also examined 14-day point-prevalence abstinence at multiple time points, and used event-history analyses to assess progression to abstinence, lapsing, and relapsing. Analyses adjusted for group differences in age and baseline smoking, and considered several potential moderators of treatment effects. RESULTS: Nicotine gum did not significantly improve outcomes on any measure. Biochemically verified 6-month continuous abstinence rates were 7.2% for active gum and 5.3% for placebo (AOR = 1.39, 0.58-3.29, p > .25). ITS with any degree of dependence (Fagerstrom Test of Nicotine Dependence scores >0) showed poorer outcomes on multiple endpoints, and did more poorly on active gum on some outcomes. Gum use was low, starting at 1 gum per day on average and declining over time. CONCLUSIONS: Nicotine gum (2 mg), used intermittently, did not improve cessation rates among ITS, including those demonstrating some degree of dependence. IMPLICATIONS: Nicotine replacement has been extensively tested with daily smokers, especially those who smoke relatively heavily. Nondaily smoking is now common, creating a need for treatment for ITS. Despite evidence that ITS' smoking is motivated by nicotine-seeking, a theoretically and empirically derived situational approach to using acute nicotine replacement was not successful at helping ITS quit. Gum use was low; whether higher or more frequent dosing is needed, or whether an entirely different approach is needed, is not clear. Effective treatment options are needed for ITS, especially those with some degree of dependence.

How intensely nondaily smokers smoke in laboratory topography sessions correlates with cigarette smoking intensity in the field.

This study examines how well exposure in topography sessions correlates with exposure when smoking ad libitum in the field, by measuring material deposited on the filters of cigarettes smoked in the lab and in the field. The data were collected in a study of the effect of very low-nicotine-content versus normal-nicotine-content cigarettes in nondaily smokers. A total of 4,771 cigarette filters (323 from laboratory topography sessions, 4,448 from the field) from 123 nondaily smokers were analyzed. Optical scanning assessed density of deposits on cigarette filters, an indicator of smoke drawn through the cigarette and thus of exposure. Both during baseline, when participants smoked their own cigarettes, and during treatment, when smoking experimental cigarettes, lab and field exposure were well correlated (both rs = .62, p < .0001; r = .69, p < .0001, when analyzing all available data). Total puff volume also correlated with field exposure (p < .0001). In all analyses, exposure was slightly lower in the lab than in the field (p < .001). Exposure in laboratory topography sessions is a good indicator of exposure during ad libitum smoking in the field, both when smokers are smoking their own, varied, brands of cigarettes and when they are smoking uniform research cigarettes with very low or normal nicotine content. At least among nondaily smokers, topography measures of smokers' exposure are generalizable. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Very-low-nicotine-content cigarettes and dependence among non-daily smokers.

BACKGROUND: The US Food and Drug Administration is considering reductions in the nicotine content of cigarettes to reduce smoking and tobacco dependence. A randomized study showed that even non-daily, intermittent smokers (ITS) reduced their cigarette consumption when switched to very-low-nicotine-content cigarettes (VLNCCs). This paper assesses whether switching ITS to VLNCCs results in decreased dependence and whether subsequent cigarette consumption is mediated by decreased dependence. METHODS: ITS randomized to VLNCCs (n = 118) or normal nicotine content cigarettes (n = 120) completed multiple measures of dependence (Fagerstrom Test of Nicotine Dependence [FTND], Nicotine Dependence Syndrome Scale [NDSS], Wisconsin Inventory of Smoking Dependence Motives [WISDM], and Hooked on Nicotine Checklist [HONC]) at Baseline and 2, 6, and 10 weeks after randomization. A principal component factor score captured common variance among these measures (except FTND). Cigarettes per day (CPD) was assessed by three convergent methods. RESULTS: Switching ITS to VLNCCs reduced dependence on all measures except the WISDM Secondary Dependence Motives and HONC. Except for the effects on the factor score, these effects of VLNCCs could be accounted for by contemporaneous CPD. Week-2 dependence measures did not prospectively predict weeks 3-4 CPD, once antecedent dependence and CPD were accounted for. "Cheating" among participants who appear to have smoked conventional cigarettes did not affect the findings. DISCUSSION: Among ITS, switching to VLNCCs results in reduced tobacco dependence. However, the reductions in dependence appear to be secondary to effects on cigarette consumption, and do not appear to be an independent predictor or cause of reduced cigarette consumption.

Do non-daily smokers compensate for reduced cigarette consumption when smoking very-low-nicotine-content cigarettes?

RATIONALE: The Food and Drug Administration is considering severely restricting the nicotine in cigarettes, to reduce smoking. A study showed that non-daily, intermittent smokers (ITS) randomized to very-low-nicotine-content cigarettes (VLNCCs) reduced their cigarette consumption. OBJECTIVES: To assess whether increased smoking intensity of VLNCCs compensated for some of the reduced cigarette consumption. METHODS: After a 2-week baseline smoking their own-brand cigarettes, 118 ITS were randomized to VLNCCs (~ 1 mg nicotine/g tobacco), and 120 to normal-nicotine-content cigarettes (NNCCs; ~ 16 mg/g) for 10 weeks. Laboratory measures of smoking intensity-total puff volume and carbon monoxide (CO) boost-assessed single cigarettes smoked in up to three laboratory topography sessions. Field measures assessed returned cigarette butts, averaged over up to five 2-week intervals: the mass of tobacco burned (computed from residual mass of butts) and the intensity of smoking (by scanning of returned filters). Analysis was by mixed model random effects models using baseline values as covariates. RESULTS: ITS in the VLNCC group puffed less smoke in topography sessions (-38.50 mL [-75.21, -1.78]; p < 0.04), but showed no difference in CO boost. Participants in the VLNCC group burned 0.02 [0.04, 0.002] grams less tobacco per cigarette (p < 0.03). Analysis of filters showed their smoking intensity declined over time, compared to NNCC participants (p < 0.04). "Cheating" by smoking normal cigarettes did not moderate these effects. CONCLUSIONS: ITS did not increase their smoking intensity when switched to VLNCCs; indeed, their smoking intensity decreased. Reductions in cigarette consumption seen when ITS are switched to VLNCCs were not compensated by increased smoking intensity.

Interaction between ethnicity and smoker type with dependence: A comparison of daily and intermittent African American and Caucasian smokers.

Ethnic differences in smoking patterns and dependence have been observed between Caucasian and African American smokers: African Americans who smoke are more likely to be intermittent smokers (ITS), and daily smokers (DS) consume fewer cigarettes yet report more dependence. Participants' (N = 482, 67% Caucasian, 54% ITS) dependence was assessed by primary and secondary dependence subscales of the Wisconsin Inventory of Smoking Dependence Motives, the Nicotine Dependence Syndrome Scale, the Hooked on Nicotine Checklist, the Fagerström Test of Nicotine Dependence, and time to first cigarette after waking. We tested associations with dependence for ethnicity, smoker type, and an Ethnicity × Smoker Type interaction, using multivariable linear regression, with adjustment for age, sex, and education. Additional models adjusted for cigarettes per day and history of daily smoking. There was a significant interaction between ethnicity and smoker type for 5 of 6 measures of dependence (each scale assessed separately), such that African American ITS reported more dependence than Caucasian ITS, whereas dependence did not differ by ethnicity among DS. African American ITS smoked more cigarettes per day and were more likely to have a history of daily smoking than Caucasian ITS; after further adjustments for these differences, there were no significant interactions of ethnicity and smoker type for any measure. Among DS, dependence did not differ by race. African American ITS were more dependent than Caucasian ITS; this difference was explained by higher cigarette consumption and a higher proportion converted from DS to ITS among African Americans versus Caucasians. (PsycINFO Database Record

Nondaily Smokers' Changes in Cigarette Consumption With Very Low-Nicotine-Content Cigarettes: A Randomized Double-blind Clinical Trial.

Importance: The US Food and Drug Administration is considering limiting cigarettes to very low nicotine levels. Cigarette consumption of nondaily intermittent smokers (ITS), who compose one-third of US adult smokers, could feasibly increase or could be unaffected if their smoking is not motivated by nicotine seeking. Objective: To compare cigarette consumption in ITS receiving very low-nicotine-content cigarettes (VLNCCs) or identical normal-nicotine-content cigarettes (NNCCs). Design, Setting, and Participants: This randomized double-blind clinical trial was conducted from June 2015 to July 2017 at a single US site. Volunteer ITS not planning to quit were recruited via media. Overall, 297 individuals enrolled, and 238 were randomized. Analyses were intent-to-treat. Interventions: After a 2-week baseline of smoking their own brand of cigarettes provided gratis, ITS were randomized to VLNCCs or NNCCs for 10 weeks. Main Outcomes and Measures: The number of cigarettes per day (CPD) was assessed by real-time reporting, timeline follow-back reports, and cigarette butt counts. The primary outcome was change in CPD from baseline to weeks 9 to 10 of intervention, adjusting for baseline CPD. Results: The mean (SD) age of the 238 randomized participants was 37.9 (13.8) years. Of 238 participants, 108 (45%) were men. At baseline, the mean (SD) CPD was 3.1 (2.9). In intent-to-treat analyses using multiple imputation to address missing data, the VLNCC group had a mean decrease of 1.6 CPD (95% CI, 1.1-2.0; 51% of baseline) vs 0.05 decrease with NNCCs (95% CI, -0.5 to 0.4; 2% of baseline). Treatment group differences were not materially moderated by sex, race/ethnicity, or history of daily smoking. Cheating with conventional cigarettes, inferred from cotinine assays, was more common in the VLNCC group (OR, 2.95; 95% CI, 1.54-5.66), but sensitivity analyses showed significant VLNCC effects among the compliant participants as well. In longitudinal analysis of CPD over time with random intercept and slope, the VLNCC and NNCC groups differed significantly in both linear (-0.15; 95% CI, -0.22 to -0.08; P < .001) and quadratic (0.0026; 95% CI, 0.0010-0.0042; P = .002) trends: CPD dropped by 43.8% in the VLNCC group over 4 weeks, then leveled off thereafter. Abstinence (intent-to-treat, biochemically verified) in weeks 9 to 10 postrandomization did not differ significantly by treatment group (VLNCC, 10.2% vs NNNC, 5.0%; P = .28). Conclusions and Relevance: Switching to VLNCCs caused substantial smoking reduction among ITS but did not significantly increase abstinence. Response to a VLNCC intervention suggests that nicotine-seeking motivates ITS' smoking. Trial Registration: ClinicalTrials.gov Identifier: NCT02228824.

Three approaches to quantifying cigarette consumption: Data from nondaily smokers.

Quantifying cigarette consumption is fundamental to smoking research. We examine the correspondence among 3 methods of capturing cigarette consumption in nondaily smokers. In the study, 232 nondaily smokers recorded cigarette consumption over 2 weeks of ad libitum smoking (total = 3,303 days) using 3 methods: (a) interactive voice response (IVR; calling an automated telephone line when they smoked), (b) butts (storing and returning the butts of cigarettes smoked), and (c) time-line follow-back (TLFB; retrospectively reporting daily consumption). Analyses examined relationships among the measures (cigarettes per day and proportion of days abstinent) for the average over 2 weeks and for each day. In averaged data, the methods were highly correlated for both quantity smoked and percentage of abstinent days (rs > .95); the average was very reliable (α = .99). All 3 methods showed similar, very strong relationships to urinary cotinine (rs > .70). Estimates of the percentage of days abstinent differed modestly but significantly by method (butts [32%] > TLFB [31%] > IVR [28%]). For individual days, there was no significant difference in cigarettes per day by method, the 3 methods correlated highly (rs = .75-.96), and agreement on abstinence was very high (≥90%; κs ≥ .95). In nondaily smokers reporting smoking by IVR, butts, and TLFB, the resulting estimates of cigarette consumption and abstinence are highly concordant and equivalent. The composite (average) of the 3 methods yields a highly reliable estimate of cigarette-smoking behavior in this population. In contrast to past studies, this study suggests these 3 methods are equivalent and implies that any 1 can be used by nondaily smokers. (PsycINFO Database Record

Increases in Cigarette Consumption and Decreases in Smoking Intensity When Nondaily Smokers Are Provided With Free Cigarettes.

Introduction: Studies testing novel tobacco products often provide participants with free product and assess consumption. Some, but not all, studies find that providing free cigarettes increases smoking. We tested changes in smoking when free cigarettes were provided to nondaily, intermittent smokers, who constitute one-third of US adult smokers. Methods: Cigarette consumption was assessed by Time-Line Follow-Back in 235 intermittent smokers for two 2-week periods: when providing their own cigarettes and when provided own-brand cigarettes for free. Smoking topography and carbon monoxide boost were assessed for one cigarette at the end of each period. Results: Cigarette consumption increased significantly, by 66% (from 1.98 to 3.28 cigarettes per day), when cigarettes were available for free; both the number of days the subjects smoked and the number of cigarettes on those days increased. The increases were significantly greater among African Americans, those Fagerström Tobacco Nicotine Dependence scores >0, those with incomes less than US $25,000 per year, those who engaged in greater conscious restraint of smoking, and for smokers of menthol cigarettes, or "longs." Smoking intensity (smoke volume, by topography) and carbon monoxide boost decreased significantly when cigarettes were provided for free. Conclusions: Providing intermittent smokers with free cigarettes substantially increased their smoking while decreasing smoking intensity. The increases in smoking varied according to multiple individual and cigarette-type differences. These phenomena may complicate interpretation of studies that compare consumption of a free test product with cigarette consumption or constituent exposure when smokers are providing their own cigarettes. They also suggest that cigarette cost and variations in low-level dependence and in smoking restraint are factors in nondaily smoking. Implications: The study shows that providing nondaily smokers with free cigarettes increases cigarette consumption, but does differentially for different subgroups and cigarette types, while also decreasing smoking intensity. This suggests the value of using free-cigarette baseline data in studies where interventions provide free cigarettes.

Does laboratory cue reactivity correlate with real-world craving and smoking responses to cues?

BACKGROUND: Laboratory cue reactivity (CR) assessments are used to assess smokers' responses to cues. Likewise, EMA recording is used to characterize real-world response to cues. Understanding the relationship between CR and EMA responses addresses the ecological validity of CR. METHODS: In 190 daily smokers not currently quitting, craving and smoking responses to cues were assessed in laboratory CR and by real-world EMA recording. Separate CR sessions involved 5 smoking-relevant cues (smoking, alcohol, negative affect, positive affect, smoking prohibitions), and a neutral cue. Subjects used EMA to monitor smoking situations for 3 weeks, completing parallel situational assessments (presence of others smoking, alcohol consumption, negative affect, positive affect, and smoking prohibitions, plus current craving) in smoking and non-smoking occasions (averaging 70 and 60 occasions each). Analyses correlated CR craving and smoking cue responses with EMA craving and smoking correlations with similar cues. RESULTS: Although some cues did not show main effects on average craving or smoking, a wide range of individual differences in response to cues was apparent in both CR and EMA data, providing the necessary context to assess their relationship. Laboratory CR measures of cue response were not correlated with real-world cue responses assessed by EMA. The average correlation was 0.03; none exceeded 0.32. One of 40 correlations examined was significantly greater than 0. CONCLUSIONS: Laboratory CR measures do not correlate with EMA-assessed craving or smoking in response to cues, suggesting that CR measures are not accurate predictors of how smokers react to relevant stimuli in the real world.

Social smoking among intermittent smokers.

BACKGROUND: "Social smoking" - smoking mostly or even only with others - may be an important pattern that implies smoking motivated extrinsically by social influences. Non-daily smokers (intermittent smokers; ITS) are often assumed to be social smokers, with some authors even assuming that all ITS are social smokers (SS+). We sought to identify and characterize social smokers in a sample of ITS. METHODS: 204 adult ITS (smoking 4-27 days/month) recorded the circumstances of smoking in their natural settings using Ecological Momentary Assessment, while also recording their circumstances in nonsmoking moments. SS+ were defined as ITS who were with others when they smoked most of their cigarettes, and who were ≥50% more likely to be with others when smoking than when not. RESULTS: Only 13% of ITS were SS+. Although defined solely on the basis of presence of others, SS+ showed a distinct pattern of smoking across multiple dimensions: compared to other ITS (who were significantly less likely to smoke when with others), SS+ smoking was more associated with socializing, being with friends and acquaintances, drinking alcohol, weekends, evening or nighttime, being in other people's homes, but not their own home. SS+ smoking was low in the morning and increased in the evening. SS+ smoked fewer days/week and were less dependent, but did not differ demographically. CONCLUSIONS: Social smoking does constitute a highly distinct smoking pattern, but is not common among adult ITS.

Cue reactivity in converted and native intermittent smokers.

INTRODUCTION: Nondaily, or intermittent smokers (ITS), who constitute a substantial fraction of U.S. smokers, are thought to smoke in response to cues. Previous cue reactivity research showed no difference between ITS and daily smokers in response to cues. This report examines whether "converted" ITS (CITS) with a history of past daily smoking differ from "native" ITS (NITS) in craving and smoking in response to cues. METHODS: A total of 146 CITS (who previously smoked daily for at least 6 months) and 73 NITS participated. Participants were exposed to 5 active cues (smoking, alcohol, negative affect, positive affect, and smoking prohibitions) and a control neutral cue, in separate sessions. Changes in craving were assessed pre-post cue exposure. Smoking behavior (smoking [y/n], smoking latency, number of cigarettes, number of puffs, and increase in carbon monoxide [CO]) was observed. Analyses contrasted response to each active cue compared to the neutral cue and controlled for order effects and for time since last cigarette, which differed between groups. RESULTS: Regardless of cues, CITS reported higher craving and greater change in craving, were more likely to smoke, tended to progress faster to smoking, and showed greater increases in CO when they did smoke. NITS and CITS showed similar cue reactivity on most measures, though NITS took more puffs after viewing smoking cues (compared to neutral) than did CITS. CONCLUSIONS: Though CITS show some remnants of their history of daily smoking, CITS and NITS demonstrate similar cue reactivity, suggesting that they would not require different behavioral approaches to help them quit.

Determining the mechanism and parameters of hydrate formation and loss in glucose.

Water-solid interactions are known to play a major role in the chemical and physical stability of food materials. Despite its extensive use throughout the food industry, the mechanism and parameters of hydrate formation and loss in glucose are not well characterized. Hydrate formation in alpha-anhydrous glucose (α-AG) and hydrate loss in glucose monohydrate (GM) were studied under equilibrium conditions at various relative humidity (RH) values using saturated salt slurries for 1 y. The mechanism of hydrate formation and hydrate loss were determined through mathematical modeling of Dynamic Vapor Sorption data and Raman spectroscopy was used to confirm the mechanisms. The critical temperature for hydrate loss in GM was determined using thermogravimetric analysis (TGA). The moisture sorption profiles of α-AG and GM were also studied under dynamic conditions using an AquaSorp Isotherm Generator. Hydrate formation was observed at and above 68% RH at 25 °C and the conversion of α-AG to GM can best be described as following a nucleation mechanism, however, diffusion and/or geometric contraction mechanisms were also observed by Raman spectroscopy subsequent to the coalescence of initial nucleation sites. Hydrate loss was observed to occur at and below 11% RH at 25 °C during RH storage and at 70 °C during TGA. The conversion of GM to α-AG follows nucleation and diffusion mechanisms. Hydrate formation was evident under dynamic conditions in α-AG and GM prior to deliquescence. This research is the first to report hydrate formation and loss parameters for crystalline α-AG and GM during extended storage at 25 ˚C.

Nicotine dependence, "background" and cue-induced craving and smoking in the laboratory.

BACKGROUND: Nicotine dependence has been associated with higher "background" craving and smoking, independent of situational cues. Due in part to conceptual and methodological differences across past studies, the relationship between dependence and cue-reactivity (CR; e.g., cue-induced craving and smoking) remains unclear. METHODS: 207 daily smokers completed six pictorial CR sessions (smoking, negative affect, positive affect, alcohol, smoking prohibitions, and neutral). Individuals rated craving before (background craving) and after cues, and could smoke following cue exposure. Session videos were coded to assess smoking. Participants completed four nicotine dependence measures. Regression models assessed the relationship of dependence to cue-independent (i.e., pre-cue) and cue-specific (i.e., pre-post cue change for each cue, relative to neutral) craving and smoking (likelihood of smoking, latency to smoke, puff count). RESULTS: Dependence was associated with background craving and smoking, but did not predict change in craving across the entire sample for any cue. Among alcohol drinkers, dependence was associated with greater increases in craving following the alcohol cue. Only one dependence measure (Wisconsin Inventory of Smoking Dependence Motives) was consistently associated with smoking reactivity (higher likelihood of smoking, shorter latency to smoke, greater puff count) in response to cues. CONCLUSION: While related to cue-independent background craving and smoking, dependence is not strongly associated with laboratory cue-induced craving under conditions of minimal deprivation. Dependence measures that incorporate situational influences on smoking correlate with greater cue-provoked smoking. This may suggest independent roles for CR and traditional dependence as determinants of smoking, and highlights the importance of assessing behavioral CR outcomes.

Craving in intermittent and daily smokers during ad libitum smoking.

INTRODUCTION: This study aimed to assess average and peak craving intensity among nondaily intermittent smokers (ITS) in smoking episodes and when not smoking compared to that of daily smokers (DS). METHODS: Two hundred and twelve ITS and 194 DS monitored their smoking and craving for 3 weeks using Ecological Momentary Assessment methods. Craving was assessed (0-100 scale) when subjects lit a cigarette and at random times when not smoking; 48,469 observations were analyzed using generalized estimating equations. RESULTS: ITS experienced craving, including intense craving; their 95th percentile intensity averaged 77.7 ± 22.5 out of 100 (higher among DS: 89.1 ± 14.5). ITS reported lower craving than DS, both when smoking and when not smoking. In both groups, craving was less intense when not smoking (DS: 71.1 ± 20.7 vs. 59.83 ± 21.97; ITS: 59.91 ± 23.03 vs. 26.63 ± 19.87), but the difference was significantly greater among ITS. Among ITS, the probability of smoking rose continuously as craving increased over the full range of the scale. In contrast, among DS the probability of smoking rose until the midpoint of the scale, after which the relationship flattened. Findings were mostly similar for ITS with and without a history of past daily smoking. CONCLUSIONS: ITS do experience craving, including intense craving. The relationship between craving and smoking is stronger among ITS because DS experience moderate craving even between cigarettes. In contrast, ITS appear to experience craving in limited situations associated with smoking, suggesting that their craving and smoking may be driven by transient cues rather than endogenous needs.

Smoking patterns and stimulus control in intermittent and daily smokers.

Intermittent smokers (ITS) - who smoke less than daily - comprise an increasing proportion of adult smokers. Their smoking patterns challenge theoretical models of smoking motivation, which emphasize regular and frequent smoking to maintain nicotine levels and avoid withdrawal, but yet have gone largely unexamined. We characterized smoking patterns among 212 ITS (smoking 4-27 days per month) compared to 194 daily smokers (DS; smoking 5-30 cigarettes daily) who monitored situational antecedents of smoking using ecological momentary assessment. Subjects recorded each cigarette on an electronic diary, and situational variables were assessed in a random subset (n=21,539 smoking episodes); parallel assessments were obtained by beeping subjects at random when they were not smoking (n=26,930 non-smoking occasions). Compared to DS, ITS' smoking was more strongly associated with being away from home, being in a bar, drinking alcohol, socializing, being with friends and acquaintances, and when others were smoking. Mood had only modest effects in either group. DS' and ITS' smoking were substantially and equally suppressed by smoking restrictions, although ITS more often cited self-imposed restrictions. ITS' smoking was consistently more associated with environmental cues and contexts, especially those associated with positive or "indulgent" smoking situations. Stimulus control may be an important influence in maintaining smoking and making quitting difficult among ITS.

Smoker reactivity to cues: effects on craving and on smoking behavior.

We assessed craving and smoking in response to smoking-relevant cues. Two hundred seven daily smokers viewed images related to 1 of 6 cue sets (cigarettes, positive and negative affect, alcohol, smoking prohibitions, and neutral cues) in separate sessions. Compared with neutral cues, cigarette cues significantly increased craving, and positive affect cues significantly decreased craving. When subjects were then allowed to smoke during continuing cue exposure, cues did not affect the likelihood of smoking or the amount smoked (number of cigarettes, number of puffs, puff time, or increased carbon monoxide). However, craving intensity predicted likelihood of smoking, latency to smoke, and amount smoked, with craving increases after cue exposure making significant independent contributions. Some craving effects were curvilinear, suggesting that they are subject to thresholds and might not be observed under some circumstances.