Higher macrophage superoxide anion production in coronary artery disease (CAD) patients with Type D personality

BACKGROUND Type D personality (Type D) is an independent psychosocial risk factor for poor cardiac prognosis and increased mortality in patients with cardiovascular disease (CVD), but the involved mechanisms are poorly understood. Macrophages play a pivotal role in atherosclerosis, the process underlying coronary artery disease (CAD). We investigated macrophage superoxide anion production in production in CAD patients with and without Type D. METHODS AND RESULTS We studied 20 male CAD patients with Type D (M:66.7±9.9years) and 20 age-matched male CAD patients without Type D (M:67.7±8.5years). Type D was measured using the DS14 questionnaire with the two subscales 'negative affectivity' and 'social inhibition'. We assessed macrophage superoxide anion production using the WST-1 assay. All analyses were controlled for potential confounders. CAD patients with Type D showed higher superoxide anion production compared to CAD patients without Type D (F(1,38)=15.57, p<0.001). Complementary analyses using the Type D subscales 'negative affectivity' and 'social inhibition', and their interaction as continuous measures, showed that both Type D subscales (negative affectivity: (ß=0.48, p=0.002, R(2)=0.227); social inhibition: (ß=0.46, p=0.003, R(2)=0.208)) and their interaction (ß=0.36, p=0.022, R(2)=0.130) were associated with higher WST-1 reduction scores. Results remained significant when controlling for classical CVD risk factors (i.e. body mass index, mean arterial blood pressure), atherosclerosis severity (i.e. intima media thickness, presence of carotid plaques), and psychological factors (depressive symptom severity, chronic stress). CONCLUSIONS Our results indicate higher macrophage superoxide anion production in CAD patients with Type D compared to those without Type D. This may suggest a mechanism contributing to increased morbidity and mortality in CAD patients with Type D.

Comparing reading processes on e-ink displays and print

E-book reading devices open new possibilities in the field of reading. More activities than just reading a book can be performed with a single electronic device. For a long time, electronic reading devices have not been favored because their active LCD displays used to have a relatively low contrast. The new generation of electronic reading devices differs from earlier ones in the nature of the display: active LCD displays have been replaced with displays based on e-ink technology, which has display properties closer to that of printed paper. Moreover, e-ink technology has higher power efficiency, thereby increasing battery life and reducing weight. At first sight, the display looks similar to paper print, but the question remains whether the reading behavior also is equal to that of reading a printed book. In the present study, we analyzed and compared reading behavior on e-reader displays and on printed paper. The results suggest that the reading behavior on e-readers is indeed very similar to the reading behavior on print. Participants shared similar proportions of regressive saccades while reading on e-readers and print. Significant differences in fixation duration suggest that e-readers, in some situations, may even provide better legibility.