Current neurovascular research
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Near Infrared Spectroscopy (NIRS) is an emerging technique for brain oxygenation monitoring in newborns complicated by acute and chronic hypoxia. However, data regarding cerebral oxygenation normal values are still lacking and matter of debate. Therefore, we investigate whether NIRS parameters in healthy preterm/term infants are gestational age and delivery modalities dependent and correlate with standard monitoring parameters. ⋯ From 34 wks onwards, rSO2 progressively decreased and FTOE increased reaching their lower dip/peak (P<0.001, for all) at 38-39 weeks. rSO2 and FTOE values were significantly different (P<0.05, for both) between preterm and term newborns when corrected for delivery modality. rSO2 correlated (P<0.001 for all) with heart (r=0.63), respiratory (r=-0.58) rate, and with arterial oxygen saturation (r=0.65). In conclusion, in the first 6-hours after birth cerebral oxygenation in healthy newborns is gestational age-dependent and correlated with routine parameters. NIRS reference curve could be particularly useful in sick newborns brain monitoring.
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That promising neuroprotectants failed to demonstrate benefit against stroke highlights the great difficulties to translate preclinical pharmacological effects in clinical outcomes. Part of this hurdle implies the complex response to injury of the neurovascular unit increasing the cerebrovascular permeability at the level of the blood-brain barrier (BBB). Previous studies reported neuroprotection in animal models upon activation of the nuclear receptor PPARalpha(peroxisome proliferator-activated receptor)alpha, but the cellular targets at the BBB level remain largely unexplored. ⋯ Furthermore, co-cultures with ECs from PPAR-alpha-deficient mice revealed that FA had no effect on OGD-induced hyperpermeability. No transcriptional modulation of classical PPAR-alpha target genes such as SOD, ICAM-1, VCAM-1, ACO, CPT-1, PDK-4 or ET-1 was observed in wild type mouse ECs. In conclusion, these results suggest that part of the preventive PPAR-alpha-mediated protection may occur via BBB ECs by limiting hyperpermeability.