Diabetes-induced fibrotic matrix inhibits intramembranous bone healing

Diabetes diminishes bone healing and ossification. Reduced bone formation in intramembranous ossification is known, yet the mechanism(s) behind impaired intramembranous bone healing are unclear. Here we report the formation of a fibrotic matrix during healing of intramembranous calvarial bone defects that appears to exclude new bone growth. Our histological analyses of 7-day and 14-day calvaria bone healing tissue in chemically-induced diabetic mice and non-diabetic mice showed the accumulation of a non-mineralized fibrotic matrix, likely as a consequence of unresolved hematomas under diabetic conditions. Elevated mRNA and enzyme activity levels of lysyl oxidase on day 7 in diabetic bone healing tissues also supports that the formation of a fibrotic matrix occurs in these tissues. Based on these findings, we propose that elevated fibroblast proliferation and formation of a non-mineralized fibrotic extracellular matrix in diabetes contributes to deficient intramembranous bone healing in diabetes. A greater understanding of this process has relevance to managing dental procedures in diabetics in which successful outcomes depend on intramembranous bone formation.     

Public perceptions of climate change adaptation in Singapore dealing with forecasted sea level rise

Abstract

Perceptions of the populace play a central and decisive role in advancing pro-environmental policies. To study attitudes and perceptions towards environmental measures, we apply several items of New Ecological Paradigm (NEP) and Value-Belief-Norm (VBN) theories to cross-examine the public perceptions of climate change in the urban city-state of Singapore through analysis of quantitative questionnaires and qualitative semi-structured interviews. The perceptions were explored about ecological orientation (two dimensions of NEP: level of concern, self-reported knowledge) and environmental behavior (two dimensions of VBN: acceptance and support of national adaptation measures, confidence in adaptation). There is a moderate to high concern for climate change, in general, and sea level rise and flooding, in particular, and the concern is expected to increase in the future. Individuals who indicated a higher level of concern are likely to be more accepting and supportive of climate change measures. Also, while the majority of the populace are amenable to legislative measures from the government, such as enacting pro-environmental laws and more are agreeable to accepting cuts on living standards, as opposed to paying more in prices and taxes. Ecological orientation does not translate directly into environmental behavior, highlighting the gulf between perception and behavior in Singapore.