Robert A. Wise

While the evidence is strong that dopamine plays some fundamental and special role in the rewarding effects of brain stimulation, psychomotor stimulants, opiates, and food, the exact nature of that role is not clear. One thing is clear: Dopamine is not the only reward transmitter, and dopaminergic neurons are not the final common path for all rewards. Dopamine antagonists and lesions of the dopamine systems appear to spare the rewarding effects of nucleus accumbens and frontal cortex brain stimulation (Simon et al 1979) and certainly spare the rewarding effects of apomorphine (Roberts & Vickers 1988). It is clear that reward circuitry is multisynaptic, and since dopamine cells do not send axons to each other or receive axons from each other, dopamine can at best serve as but a single link in this circuitry. If dopamine is not a final common path for all rewards, could it be an intermediate common path for most rewards? Some workers have argued against such a view, but at present they must do so on incomplete evidence. For example, Phillips (1984) has argued that there must be multiple reward systems, functionally independent and organized in parallel with one another. His primary evidence, however, is the fact that brain stimulation is rewarding at different levels of the nervous system. As we have seen in the case of midline mesencephalic stimulation, the location of the electrode tip in relation to the dopamine cells and fibers tells us little about the role of dopamine in brain stimulation reward. It seems clear that the ventral tegmental dopamine system plays a critical role in midline mesencephalic reward, despite the distance from the electrode tip to the dopamine cells where morphine causes its dopamine-dependent facilitory effects or to the dopamine terminals where low-dose neuroleptics presumably cause theirs. Until pharmacological challenge has been extended to the cases discussed by Phillips, we can only speculate as to the role of dopamine in each of those cases. In the cases where pharmacological challenge has been examined, only nucleus accumbens and frontal cortex have been found to have dopamine-independent reward sites. It is not consistent with the dopamine hypothesis that dopamine-independent reward sites should exist in these areas, since any reward signals carried to nucleus accumbens or frontal cortex by dopamine fibers would-unless we are to believe that reward "happens" at these sites-have to be carried to the next stage of the circuit by nondopaminergic fibers (there are no dopaminergic cell bodies in any of the dopamine terminal areas).(ABSTRACT TRUNCATED AT 400 WORDS)

BACKGROUND: We conducted a double-blind, randomized, placebo-controlled trial to determine the effects of oral cyclophosphamide on lung function and health-related symptoms in patients with evidence of active alveolitis and scleroderma-related interstitial lung disease. METHODS: At 13 clinical centers throughout the United States, we enrolled 158 patients with scleroderma, restrictive lung physiology, dyspnea, and evidence of inflammatory interstitial lung disease on examination of bronchoalveolar-lavage fluid, thoracic high-resolution computed tomography, or both. Patients received oral cyclophosphamide (< or =2 mg per kilogram of body weight per day) or matching placebo for one year and were followed for an additional year. Pulmonary function was assessed every three months during the first year, and the primary end point was the forced vital capacity (FVC, expressed as a percentage of the predicted value) at 12 months, after adjustment for the baseline FVC. RESULTS: Of 158 patients, 145 completed at least six months of treatment and were included in the analysis. The mean absolute difference in adjusted 12-month FVC percent predicted between the cyclophosphamide and placebo groups was 2.53 percent (95 percent confidence interval, 0.28 to 4.79 percent), favoring cyclophosphamide (P<0.03). There were also treatment-related differences in physiological and symptom outcomes, and the difference in FVC was maintained at 24 months. There was a greater frequency of adverse events in the cyclophosphamide group, but the difference between the two groups in the number of serious adverse events was not significant. CONCLUSIONS: One year of oral cyclophosphamide in patients with symptomatic scleroderma-related interstitial lung disease had a significant but modest beneficial effect on lung function, dyspnea, thickening of the skin, and the health-related quality of life. The effects on lung function were maintained through the 24 months of the study.

BACKGROUND: -agonist (LABA), as compared with dual therapy (either inhaled glucocorticoid-LABA or LAMA-LABA), are uncertain. METHODS: In this randomized trial involving 10,355 patients with COPD, we compared 52 weeks of a once-daily combination of fluticasone furoate (an inhaled glucocorticoid) at a dose of 100 μg, umeclidinium (a LAMA) at a dose of 62.5 μg, and vilanterol (a LABA) at a dose of 25 μg (triple therapy) with fluticasone furoate-vilanterol (at doses of 100 μg and 25 μg, respectively) and umeclidinium-vilanterol (at doses of 62.5 μg and 25 μg, respectively). Each regimen was administered in a single Ellipta inhaler. The primary outcome was the annual rate of moderate or severe COPD exacerbations during treatment. RESULTS: The rate of moderate or severe exacerbations in the triple-therapy group was 0.91 per year, as compared with 1.07 per year in the fluticasone furoate-vilanterol group (rate ratio with triple therapy, 0.85; 95% confidence interval [CI], 0.80 to 0.90; 15% difference; P<0.001) and 1.21 per year in the umeclidinium-vilanterol group (rate ratio with triple therapy, 0.75; 95% CI, 0.70 to 0.81; 25% difference; P<0.001). The annual rate of severe exacerbations resulting in hospitalization in the triple-therapy group was 0.13, as compared with 0.19 in the umeclidinium-vilanterol group (rate ratio, 0.66; 95% CI, 0.56 to 0.78; 34% difference; P<0.001). There was a higher incidence of pneumonia in the inhaled-glucocorticoid groups than in the umeclidinium-vilanterol group, and the risk of clinician-diagnosed pneumonia was significantly higher with triple therapy than with umeclidinium-vilanterol, as assessed in a time-to-first-event analysis (hazard ratio, 1.53; 95% CI, 1.22 to 1.92; P<0.001). CONCLUSIONS: Triple therapy with fluticasone furoate, umeclidinium, and vilanterol resulted in a lower rate of moderate or severe COPD exacerbations than fluticasone furoate-vilanterol or umeclidinium-vilanterol in this population. Triple therapy also resulted in a lower rate of hospitalization due to COPD than umeclidinium-vilanterol. (Funded by GlaxoSmithKline; IMPACT ClinicalTrials.gov number, NCT02164513 .).

BACKGROUND: Randomized clinical trials have not yet demonstrated the mortality benefit of smoking cessation. OBJECTIVE: To assess the long-term effect on mortality of a randomly applied smoking cessation program. DESIGN: The Lung Health Study was a randomized clinical trial of smoking cessation. Special intervention participants received the smoking intervention program and were compared with usual care participants. Vital status was followed up to 14.5 years. SETTING: 10 clinical centers in the United States and Canada. PATIENTS: 5887 middle-aged volunteers with asymptomatic airway obstruction. MEASUREMENTS: All-cause mortality and mortality due to cardiovascular disease, lung cancer, and other respiratory disease. INTERVENTION: The intervention was a 10-week smoking cessation program that included a strong physician message and 12 group sessions using behavior modification and nicotine gum, plus either ipratropium or a placebo inhaler. RESULTS: At 5 years, 21.7% of special intervention participants had stopped smoking since study entry compared with 5.4% of usual care participants. After up to 14.5 years of follow-up, 731 patients died: 33% of lung cancer, 22% of cardiovascular disease, 7.8% of respiratory disease other than cancer, and 2.3% of unknown causes. All-cause mortality was significantly lower in the special intervention group than in the usual care group (8.83 per 1000 person-years vs. 10.38 per 1000 person-years; P = 0.03). The hazard ratio for mortality in the usual care group compared with the special intervention group was 1.18 (95% CI, 1.02 to 1.37). Differences in death rates for both lung cancer and cardiovascular disease were greater when death rates were analyzed by smoking habit. LIMITATIONS: Results apply only to individuals with airway obstruction. CONCLUSION: Smoking cessation intervention programs can have a substantial effect on subsequent mortality, even when successful in a minority of participants.