IGF1, an anabolic and neuroprotective factor, promotes neuronal survival by blocking apoptosis. It is released into the bloodstream by the liver, or synthesized locally by muscles and neural cells, acting in an autocrine or paracrine fashion. Intriguingly, genetic studies conducted in invertebrate and murine models also suggest that an excess of IGF1 signaling may trigger neurodegeneration. This emphasizes the importance of gaining a better understanding of the mechanisms controlling IGF1 regulation and gene transcription. In the cerebellum, Igf1 expression is activated just before birth in a subset of Purkinje cells (PCs). Mice carrying a null mutation for HLH transcription factor EBF2 feature PC apoptosis at birth. We show that Igf1 is sharply downregulated in Ebf2 null PCs starting before the onset of PC death. In vitro, EBF2 binds a conserved distal Igf1 promoter region. The pro-survival PI3K signaling pathway is strongly inhibited in mutant cerebella. Finally, Ebf2 null organotypic cultures respond to IGF1 treatment by inhibiting PC apoptosis. Consistently, wild type slices treated with an IGF1 competitor feature a sharp increase in PC death. Our findings reveal that IGF1 is required for PC survival in the neonatal cerebellum, and identify a new mechanism regulating its local production in the CNS.

CT scan of the chest and abdomen has a high diagnostic value in the evaluation of blunt trauma patients, when it is selectively performed in addition to the early conventional radiologic work-up. Unexpected pathologic findings are detected by CT scan in the majority of the patients. These findings result in an adaptation of treatment in a substantial number of the patients.

No abstract

Current literature has predominantly suboptimal design to prove terminally that the routine use of TBCT results in improved survival of blunt high-energy trauma patients. TBCT can give a change of treatment and improves time intervals in the emergency department as compared with its selective use.