Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Income inequality and cardiovascular disease risk factors in a highly unequal country: a fixed-effects analysis from South Africa

Background: Chronic stress associated with high income inequality has been hypothesized to increase CVD risk and other adverse health outcomes. However, most evidence comes from high-income countries, and there is limited evidence on the link between income inequality and biomarkers of chronic stress and risk for CVD. This study examines how changes in income inequality over recent years relate to changes in CVD risk factors in South Africa, home to some of the highest levels of income inequality globally. Methods: We linked longitudinal data from 9356 individuals interviewed in the 2008 and 2012 National Income Dynamics Study to district-level Gini coefficients estimated from census and survey data. We investigated whether subnational district income inequality was associated with several modifiable risk factors for cardiovascular disease (CVD) in South Africa, including body mass index (BMI), waist circumference, blood pressure, physical inactivity, smoking, and high alcohol consumption. We ran individual fixed-effects models to examine the association between changes in income inequality and changes in CVD risk factors over time. Linear models were used for continuous metabolic outcomes while conditional Poisson models were used to estimate risk ratios for dichotomous behavioral outcomes. Results: Both income inequality and prevalence of most CVD risk factors increased over the period of study. In longitudinal fixed-effects models, changes in district Gini coefficients were not significantly associated with changes in CVD risk factors. Conclusions: Our findings do not support the hypothesis that subnational district income inequality is associated with CVD risk factors within the high-inequality setting of South Africa

C/EBPα and β couple interfollicular keratinocyte proliferation arrest to commitment and terminal differentiation

The transcriptional regulators that couple interfollicular basal keratinocyte proliferation arrest to commitment and differentiation are yet to be identified. Here we report that the basic region leucine zipper transcription factors C/EBPalpha and C/EBPbeta are co-expressed in basal keratinocytes, and are coordinately upregulated as keratinocytes exit the basal layer and undergo terminal differentiation. Mice lacking both C/EBPalpha and beta in the epidermis showed increased proliferation of basal keratinocytes and impaired commitment to differentiation. This led to ectopic expression of keratin 14 (K14) and DeltaNp63 in suprabasal cells, decreased expression of spinous and granular layer proteins, parakeratosis and defective epidermal water barrier function. Knock-in mutagenesis revealed that C/EBP-E2F interaction was required for control of interfollicular epidermis (IFE) keratinocyte proliferation, but not for induction of spinous and granular layer markers, whereas C/EBP DNA binding was required for DeltaNp63 downregulation and K1/K10 induction. Finally, loss of C/EBPalpha/beta induced stem cell gene expression signatures in the epidermis. C/EBPs, therefore, couple basal keratinocyte cell cycle exit to commitment to differentiation through E2F repression and DNA binding, respectively, and may act to restrict the epidermal stem cell compartment.