Younger, dissatisfied, and unhealthy - Relative age in adolescence.

We investigate whether relative age (i.e. the age gap between classmates) affects life satisfaction and health in adolescence. We analyse data on students between 10 and 17 years of age from the international survey 'Health Behaviour in School-Aged Children' and find robust evidence that a twelve-month increase in relative age (i.e. the hypothetical maximum age gap between classmates) i) increases life satisfaction by 0.168 standard deviations, ii) increases self-rated general health by 0.108 standard deviations, iii) decreases psychosomatic complaints by 0.072 standard deviations, and iv) decreases chances of being overweight by 2.4 %. These effects are comparable in size to the effects of students' household socio-economic status. Finally, gaps in life satisfaction are the only ones to reduce with the increase in absolute age, but only in countries where the first tracking of students occurs at 14 years of age or later.

Inhibiting connexin channels protects against cryopreservation-induced cell death in human blood vessels.

OBJECTIVES: Cryopreserved blood vessels are being increasingly employed in vascular reconstruction procedures but freezing/thawing is associated with significant cell death that may lead to graft failure. Vascular cells express connexin proteins that form gap junction channels and hemichannels. Gap junction channels directly connect the cytoplasm of adjacent cells and may facilitate the passage of cell death messengers leading to bystander cell death. Two hemichannels form a gap junction channel but these channels are also present as free non-connected hemichannels. Hemichannels are normally closed but may open under stressful conditions and thereby promote cell death. We here investigated whether blocking gap junctions and hemichannels could prevent cell death after cryopreservation. MATERIALS AND METHODS: Inclusion of Gap27, a connexin channel inhibitory peptide, during cryopreservation and thawing of human saphenous veins and femoral arteries was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assays and histological examination. RESULTS: We report that Gap27 significantly reduces cell death in human femoral arteries and saphenous veins when present during cryopreservation/thawing. In particular, smooth muscle cell death was reduced by 73% in arteries and 71% in veins, while endothelial cell death was reduced by 32% in arteries and 51% in veins. CONCLUSIONS: We conclude that inhibiting connexin channels during cryopreservation strongly promotes vascular cell viability.

PCR-Based assay for discrimination between invasive and contaminating Staphylococcus epidermidis strains.

The discrimination between Staphylococcus epidermidis strains that contaminate and infect blood cultures is a daily challenge for clinical laboratories. The results of PCR detection of putative virulence genes were compared for contaminating strains, sepsis-related strains, catheter strains, and saprophytic strains. Multiplex PCR was used to explore the atlE gene, which is involved in initial adherence, the intercellular adhesion gene cluster (ica), which mediates the formation of the biofilm, and the agrA, sarA, and mecA genes, which might contribute to the pathogenicity of S. epidermidis. Whereas the atlE, agrA, and sarA genes were almost ubiquitously amplified, the ica and mecA genes were detected significantly more in infecting strains than in contaminating strains (P