Internet addiction and psychopathology in a community before and during an economic crisis.

Background. Internet addiction disorder (IAD) is a novel concept under scrutiny for a definite inclusion in the psychiatric taxonomy, after showing correlations with overt expressions of psychopathology. This study aims to assist the scientific dialogue concerning IAD while presenting comparative data on adolescent psychopathology before and during a major economic crisis that has affected Greece from 2010 onwards. Methods. This is a cross-sectional study of a high school student population, aged 12-18, on IAD which follows-up a 2006 survey, and is carried out 5 years later at the same school classes. A comparison on psychopathological symptoms between the two samples is carried out to confirm any underlying correlations with IAD while providing some first insight on any effects of the economic crisis on adolescent psyche. Results. Results indicate that Internet addiction is increased in this population paralleling the increase in Internet availability at home. Adolescents affected with IAD present with more psychopathological symptoms. A comparison between the 2006 and 2011 samples reveals lower rates of general psychopathology but similar burden of reported symptoms. Conclusions. Those findings are discussed in the framework of adolescent coping to adversity, individual reactions to major crises, as well as the general debate regarding the value of IAD as a distinct diagnosis. The effects of the economic crisis may have triggered an adaptive response in the adolescent population although IAD as a distinct nosological entity is clearly linked to more symptoms of overt psychopathology. Directions are offered for further research in countries affected by crises.

Hypoxia-induced collagen crosslinking as a mechanism for enhancing mechanical properties of engineered articular cartilage.

OBJECTIVE: The focus of tissue engineering of neocartilage has traditionally been on enhancing extracellular matrix and thus biomechanical properties. Emphasis has been placed on the enhancement of collagen type and quantity, and, concomitantly, tensile properties. The objective of this study was to improve crosslinking of the collagen network by testing the hypothesis that hypoxia could promote pyridinoline (PYR) crosslinks and, thus, improve neocartilage's tensile properties. METHODS: Chondrocyte expression of lysyl oxidase (LOX), an enzyme responsible for the formation of collagen PYR crosslinks, was first assessed pre- and post- hypoxia application. Then, the mechanical properties of self-assembled neocartilage constructs were measured, after 4 weeks of culture, for groups exposed to 4% O2 at different initiation times and durations, i.e., during the 1st and 3rd weeks, 3rd and 4th weeks, 4th week only, continuously after cell seeding, or never. RESULTS: Results showed that LOX gene expression was upregulated ∼20-fold in chondrocytes in response to hypoxia. Hypoxia applied during the 3rd and 4th weeks significantly increased PYR crosslinks without affecting collagen content. Excitingly, neocartilage tensile properties were increased ∼2-fold. It should be noted that these properties exhibited a distinct temporal dependence to hypoxia exposure, since upregulation of these properties was due to hypoxia applied only during the 3rd and 4th weeks. CONCLUSION: These data elucidate the role of hypoxia-mediated upregulation of LOX and subsequent increases in PYR crosslinks in engineered cartilage. These results hold promise toward applying hypoxia at precise time points to promote tensile integrity and direct construct maturation.