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Cannabis use rates continue to rise in the United States and currently cannabis is among the most widely used substances in the world. Cannabis use is associated with several mental health problems, low educational attainment, low income, and underemployment. The current study explored the tendency to experience negative affect (negative affectivity) as a factor accounting for the association between perceived distress tolerance and problems related to the use of cannabis. Participants included 203 urban adult daily cannabis users (29.2% female, M=37.7years, 63% African American). Results indicated that there was a significant indirect effect of distress tolerance via negative affectivity in terms of cannabis use problems (b=-0.58, 95%CI [-1.14, -0.21]), cannabis withdrawal (b=-0.65, 95%CI [-1.36, -0.21]), self-efficacy for quitting (b=-0.83, 95%CI [-1.85, -0.22]), and perceived barriers for cannabis cessation (b=-0.71, 95%CI [-1.51, -0.24]). The present data provide novel empirical evidence suggesting negative affectivity may help explain the relation between perceived distress tolerance and an array of clinically significant cannabis use processes. Intervention programming for daily cannabis users may benefit from targeting negative affectivity to facilitate change in cannabis use processes among users who tend to perceive that they are less capable of tolerating distress. [ABSTRACT FROM AUTHOR]

Introduction: Despite the well-known linkages between poor emotion regulation and subjective smoking motives, little is known about the role of emotion regulation in predicting smoking reinforcement behavior. This study examined the relation between difficulties in emotion regulation and puff velocity data, a behavioral index of smoking reinforcement, in adult daily cigarette smokers.Method: The current study was a secondary analysis of data collected from non-treatment seeking daily smokers (N = 124). Participants completed the Difficulties in Emotion Regulation Scale (DERS) followed by an ad libitum smoking period during which puff topography data was collected via a handheld puffing device. Puff velocity served as our puff topography index and was examined at the average and puff-to-puff level using regression and multi-level models, respectively.Results: Regression analyses showed no significant association between DERS scores and average puff velocity. In contrast, multi-level modeling found a significant quadratic time × DERS effect at the puff-to-puff level, such that those with greater emotion regulation difficulties inhaled more quickly at the initiation of the cigarette, whereas those with lower emotion regulation difficulties evidenced consistent puffing over the course of the cigarette.Discussion: Smokers with greater difficulties in emotion regulation appear to smoke in a way that maximizes delivery of nicotine, perhaps to self-regulate distress. One's style of puffing may reflect a possible behavioral marker of negative reinforcement smoking, especially in the context of emotional distress.Implications: This study was the first to explore the relationship between difficulties in emotion regulation and a behavioral measure of smoking reinforcement. [ABSTRACT FROM AUTHOR]

Abstract: [11C]MePPEP is a high affinity, CB1 receptor-selective, inverse agonist that has been studied in rodents and monkeys. We examined the ability of [11C]MePPEP to quantify CB1 receptors in human brain as distribution volume calculated with the “gold standard” method of compartmental modeling and compared results with the simple measure of brain uptake. A total of 17 healthy subjects participated in 26 positron emission tomography (PET) scans, with 8 having two PET scans to assess retest variability. After injection of [11C]MePPEP, brain uptake of radioactivity was high (e.g., 3.6 SUV in putamen at ∼60 min) and washed out very slowly. A two-tissue compartment model yielded values of distribution volume (which is proportional to receptor density) that were both well identified (SE 5%) and stable between 60 and 210 min. The simple measure of brain uptake (average concentration of radioactivity between 40 and 80 min) had good retest variability (∼8%) and moderate intersubject variability (16%, coefficient of variation). In contrast, distribution volume had two-fold greater retest variability (∼15%) and, thus, less precision. In addition, distribution volume had three-fold greater intersubject variability (∼52%). The decreased precision of distribution volume compared to brain uptake was likely due to the slow washout of radioactivity from brain and to noise in measurements of the low concentrations of [11C]MePPEP in plasma. These results suggest that brain uptake can be used for within subject studies (e.g., to measure receptor occupancy by medications) but that distribution volume remains the gold standard for accurate measurements between groups. [Copyright &y& Elsevier]

Introduction: Cigarette demand, or relative value, can be assessed via analysis of performance on a hypothetical behavioral economic cigarette purchase task (CPT). Substance purchase tasks are highly amenable to manipulation, namely, external stimuli, instructional changes, or acute stressors. In this regard, the current secondary analysis evaluates the role a novel, computerized stress induction paradigm, the Contextual-Frustration Intolerance Typing Task (C-FiTT), plays in eliciting varying levels of stress and resulting demand.Method: Daily smokers (n = 484) completed the C-FiTT wherein they were randomly assigned to one of five distress conditions: combination of task difficulty (low or high difficulty) with neutral or withdrawal cues, and a neutral control group. Tobacco demand was assessed immediately following the distress task using the hypothetical CPT.Results: The C-FiTT distress-induction task significantly increased key cigarette demand indices, including price at maximum expenditure (Pmax) and first price where consumption was suppressed to zero (breakpoint). Moreover, demand increased with severity of C-FiTT condition, with the high-difficulty condition resulting in significantly higher breakpoint and Pmax, compared to other conditions. C-FiTT condition was not related to a significant increase in Omax, intensity, or elasticity.Discussion: The novel C-FiTT paradigm produced comparable effects on tobacco demand relative to in vivo withdrawal induction, indicating that the C-FiTT is a viable procedure by which to influence demand. Reduction of internal and external stressors may be effective in lowering motivation for tobacco. These results highlight the importance of state distress in tobacco demand, and offer a potential avenue for intervention. [ABSTRACT FROM AUTHOR]

Background: Distress intolerance (DI), the perceived inability to withstand distress, is implicated in cigarette smoking maintenance. Greater DI may contribute to anticipation of negative outcomes from smoking abstinence, which in turn could contribute to withdrawal symptom severity. The current study aimed to evaluate (1) the association between DI and acute abstinence expectancies and (2) the potential mediating role of abstinence expectancies in the relationship between DI and withdrawal symptom severity.Method: Participants (n = 444) were daily smokers who reported at least one prior quit attempt, participating in a larger online study on distress and smoking. DI, subjective nicotine withdrawal, and smoking abstinence expectancies were assessed using the Distress Tolerance Scale (DTS), Minnesota Nicotine Withdrawal Scale (MNWS), and Smoking Abstinence Expectancies Questionnaire (SAEQ).Results: DTS was significantly negatively associated with SAEQ, specifically Negative Mood (r = -0.37, p < .001), Somatic Symptoms (r = -0.47, p < .001), and Harmful Consequences (r = -0.59, p < .001) subscales, but was not associated with Positive Expectancies subscale (r = 0.05, p = .31). Results indicated a significant effect of DTS on withdrawal symptom severity via SAEQ. Follow-up analyses indicated that the indirect effects were driven specifically by SAEQ Negative Mood and Harmful Consequences subscales.Discussion: DI is related to more negative abstinence expectancies, particularly affective aspects of abstinence, which may contribute to the severity of nicotine withdrawal symptoms. This study provides initial evidence of a specific cognitive process that may explain why DI contributes to heightened subjective experience of nicotine withdrawal symptoms. [ABSTRACT FROM AUTHOR]

The antibacterial activity in vitro of piperacillin on strains commonly isolated in hospital practice in 1986-88 was compared with that obtained for piperacillin from 1981 to 1982 and with the activity of other antibiotics usually employed. Piperacillin showed a good antibacterial activity on Gram-positive and Gram-negative strains, while few resistant strains were found.