Molecular regulation of UVB-induced cutaneous angiogenesis

We determined whether cutaneous angiogenesis induced by exposure of mice to ultraviolet-B (UVB) radiation is associated with an imbalance between positive and negative angiogenesis-regulating molecules. Unshaved C3H/HeN mice were exposed to a single dose (15 kJ per m2) of UVB. At various times, the mice were killed, and their external ears were processed for routine histology and immunohistochemistry. Antibodies against proliferating cell nuclear antigen and bromodeoxyuridine identified dividing cells. Antibodies against CD31/ PECAM-1 identified endothelial cells, and antibodies against basic fibroblast growth factor (bFGF), vascular endothelial growth factor/vascular permeability factor, and interferon-beta (IFN-beta) identified angiogenesis-regulating molecules. Epidermal hyperplasia was documented by 48 h and reached a maximum on day 7 after exposure to UVB. The expression of bFGF increased by 24 h, whereas the expression of IFN-beta decreased by 72 h after exposure to UVB. The expression of vascular endothelial growth factor/vascular permeability factor increased slightly after irradiation. The altered balance between bFGF and IFN-beta was associated with increased endothelial cell proliferation (bromodeoxyuridine + CD31 + cells) within existing blood vessels, leading to telangiectasia and new blood vessels. UV-induced epidermal hyperplasia and cutaneous angiogenesis were highest in IFN-alpha/beta receptor knockout mice. These results demonstrate that in response to UVB radiation, dividing keratinocytes produce a positive angiogenic molecule (bFGF) but not a negative angiogenic molecule (IFN-beta), and that this altered balance is associated with enhanced cutaneous angiogenesis.     

Wanted: institutions for balancing global food and energy markets

The increasing demand for biomass for energy use is further escalating existing food security risks. Managing these risks is a task for global institutions. These should ensure timely investment in the world’s capacity for producing biomass and balance the use of this biomass for foods and for non-foods. To achieve this, institutional arrangements for global food markets must fulfil two important goals: reduce the short-term price instability of food markets and prevent a structural scarcity of food in the long term. This paper analyses how agro-food markets, energy markets and biofuel markets are currently regulated. As this regulation is ill-suited to manage food price instabilities and balance food and non-food use of biomass, new institutions need to be put in place. A coordinated system of global commodity management — not unlike the Commodity Control Organization proposed by Keynes for the post-WWII era — is proposed to deal with these coming challenges.     

IR studies of Re2O7 metathesis catalysts supported on alumina and phosphated alumina

FTIR data from Re₂O₇/-Al₂O₃ metathesis catalysts indicate that a low Re contents ReO₄ ions have predominantly reacted with basic surface OH groups, while at higher Re₂O₇ loadings they have also reacted with neutral and more acidic OH groups.On phosphated -Al₂O₃ the phosphate has reacted with the more acidic OH groups on the -Al₂O₃; in catalysts based on this support, the ReO₄ ^– ions have also reacted with the phosphorus-bonded OH groups already at low Re₂O₇ loadings, resulting in more active catalysts.