Nicotine-induced angiogenesis

Influence of differences in case mix on the better outcome of smokers after intravenous thrombolysis for acute cerebral ischemia

BACKGROUND/AIMS

Thrombolysis for myocardial infarction is more effective in smokers. Our aim was to determine whether smokers treated by intravenous (i.v.) rt-PA for acute cerebral ischemia have better outcomes.

METHOD

Comparison of smokers and non-smokers for baseline characteristics and month-3 outcome in patients treated by i.v. rt-PA for cerebral ischemia in Lille, France, and Belgrade, Serbia. The primary outcome was a modified Rankin scale (mRS) 0-1 or similar to the pre-stroke mRS. Secondary outcomes were an mRS 0-2 and death.

RESULTS

We included 459 patients (255 men; median age 65 years, interquartile range 52-76; 135 smokers). Smokers were younger (median 53 vs. 70 years, p < 0.0001) and had less severe strokes (median NIHSS 10 vs. 14, p < 0.0001). At month 3, they were more likely to have an mRS 0-1 [odds ratio (OR) 1.75; 95% confidence interval (CI) 1.17-2.62], or an mRS 0-2 (OR 2.90; 95% CI 1.86-4.52) and less likely to be dead (OR 0.28; 95% CI 0.13-0.61). Smoking was not independently associated with outcome after adjustment for case mix [adjusted OR ((adj)OR) 0.86; 95% CI 0.52-1.43].

CONCLUSION

Smoking does not independently influence the outcome in patients treated by rt-PA for cerebral ischemia. The better outcome in smokers is the consequence of differences in case mix.

Lung morphometry and MMP-12 expression in rats treated with intraperitoneal nicotine

Nicotine, a toxic tobacco component, plays an important role in the development of cardiovascular and lung diseases in smokers. Our objective was to investigate the effects of the intraperitoneal (i.p.) nicotine treatment in lung morphology. Wistar male rats (3-4 months old) were divided in five groups, a control one, and other groups treated with nicotine (1 mg/kg/day) for 8 days and sacrificed after 24, 48, 96, and 192 h. Morphometry was used to estimate the lung alveolar parenchyme and septal elastic fibers changes, and immunohistochemistry was performed to detect macrophage metalloelastase (MMP-12) and quantify vessels by immunolabelling with alpha-smooth muscle cells. Thickening of the alveolar septa was present in all nicotine groups, and associated with mononuclear cell infiltration, angiogenesis, and irregular areas of collapse. After 96 h, rat lungs showed macrophage, expressing MMP-12, that was also present after 192 h of recovery. Pleural and parenchyma inflammation, fibrosis and macrophage were also seen after 192 h. Intraperitoneal nicotine treated rats exhibited an increase of the volume fraction of alveolar parenchyme, a reduction of volume and surface fraction septal elastic fibers, and an increase of the numerical fraction of microvasculature vessels compared to control ones. MMP-12 was detected in groups of macrophages Wistar rats lung exhibited a progressive morphological damage after 192 hours of recovery, after 8 daily doses of 1 mg/kg body weight on i.p. nicotine.