Unilaterale Netzhautblutungen bei Säuglingen – 2 Fälle von Schütteltrauma?

A 2.5-month-old boy and a 2-month-old girl were admitted to a pediatric intensive care unit with impaired consciousness. Both infants had subdural hemorrhages. Because of presumed non-accidental head injury (NAHI) funduscopy was performed, which revealed unilateral hemorrhage in both children. After intensive differential diagnostics NAHI was suspected in both cases and a forensic medical examination was initiated. This case series is important because it shows that unilateral retinal bleeding does not exclude NAHI

Active NF-E2-related Factor (Nrf2) Contributes to Keep Endothelial NO Synthase (eNOS) in the Coupled State: ROLE OF REACTIVE OXYGEN SPECIES (ROS), eNOS, AND HEME OXYGENASE (HO-1) LEVELS*

The aim of our study was to examine in detail the impact of NF-E2-related factor (Nrf2) activation on endothelial cell function with focus on redox homeostasis and the endothelial nitric oxide synthase (eNOS) system. We administered 2-cyano-3,12-dioxooleana-1,9-dien-28-oic imidazolide (CDDO-IM), a known activator of Nrf2, to primary human umbilical vein endothelial cells. Activation of Nrf2 by CDDO-IM increased the amount of bioavailable nitric oxide (NO), a major contributor to vascular homeostasis, in naive and stressed cells. Concomitantly, intracellular reactive oxygen species were dose-and time-dependently reduced. In apparent contrast to elevated NO levels, eNOS protein expression was transiently decreased in an Nrf2-dependent manner. Employing pharmacological inhibitors as well as a small interfering RNA approach, we identified de novo protein synthesis of heme oxygenase 1 (HO-1) and its enzymatic activity as cause for the observed reduction of eNOS. We hypothesize that under redox stress, when the availability of tetrahydrobiopterin, a pivotal stoichiometric cofactor for eNOS, is limited, activation of Nrf2 leads (a) to transient reduction of eNOS protein levels and (b) to an antioxidant defense in human umbilical vein endothelial cells. Both activities ensure that a stoichiometric ratio of eNOS and tetrahydrobiopterin is sustained and that the risk of eNOS uncoupling is reduced. Our study is the first to provide a causal link between Nrf2 activation and eNOS expression and NO levels, respectively