METHODS We conducted a multicenter, observational trial that enrolled current and former smokers with COPD. We determined the association between a PA: A ratio of more than 1 and a history at enrollment of severe exacerbations ARS-1620 purchase requiring hospitalization and

then examined the usefulness of the ratio as a predictor of these events in a longitudinal follow-up of this cohort, as well as in an external validation cohort. We used logistic-regression and zero-inflated negative binomial regression analyses and adjusted for known risk factors for exacerbation.

RESULTS

Multivariate logistic-regression analysis showed a significant association between a PA: A ratio of more than 1 and a history of severe exacerbations at the time of enrollment in the trial (odds ratio, 4.78; 95% confidence interval [CI], 3.43 CB-839 mouse to 6.65; P<0.001). A PA: A ratio of more than 1 was also independently associated with an increased risk of future severe exacerbations in both the trial cohort (odds ratio, 3.44; 95% CI, 2.78 to 4.25; P<0.001) and the external validation cohort (odds ratio, 2.80; 95% CI, 2.11 to 3.71; P<0.001). In both cohorts, among all the variables analyzed, a PA: A ratio

of more than 1 had the strongest association with severe exacerbations.

CONCLUSIONS

Pulmonary artery enlargement (a PA: A ratio of > 1), as detected by CT, was associated with severe exacerbations of COPD. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov numbers, NCT00608764 and NCT00292552.)”
“Animal studies have demonstrated decreased reward responsivity during nicotine withdrawal (e.g., Epping-Jordan et al., Nature 393:76-79, 1998) and the Card Arranging Reward Responsivity Objective Test (CARROT) has recently been used to study the effect of nicotine MTMR9 withdrawal on reward responsivity in humans (e.g., Al-Adawi and Powell, Addiction 92:1773-1782, 1997; Powell et al., Biol Psychiatry 51:151-163,

2002). We investigated a suggestion that nicotine withdrawal may have additional reward-related effects apart from the reward responsivity effects already observed.

The objective of this study was to determine whether or not nicotine withdrawal results in slower improvements in performance on a card-sorting task over a series of trials.

We carried out two experiments using a modified version of the CARROT, the mCARROT, to compare the performance of human participants in nicotine withdrawal with those who were satiated.

Although withdrawal produced no direct effect on the mCARROT measure of reward responsivity, the overall sorting rate was lower, and the increase in sorting rate across successive trials was slower during nicotine withdrawal than during satiation.