EXPLORING THE ROLE OF CENTRAL VENOUS OXYGEN SATURATION IN THE EVALUATION AND MANAGEMENT OF SEVERE HYPOXEMIA IN MECHANICALLY VENTILATED PATIENTS.

Background: Although central venous oxygen saturation (ScvO 2 ) has been used as an endpoint for the treatment of circulatory shock, its role in guiding the evaluation and treatment of patients with severe hypoxemia remains to be assessed. The aim of this study was to assess the incidence of low ScvO 2 in a cohort of hypoxemic patients and the association of this finding with differences in clinical management and patient outcomes. Methods: Retrospective review of data from adult intensive care unit patients with hypoxemia who required invasive mechanical ventilation for over 24 h and had at least one ScvO 2 measured within 6 h of a PaO 2 /FiO 2 ratio <200.

Hypertension in Prenatally Undernourished Young-Adult Rats Is Maintained by Tonic Reciprocal Paraventricular-Coerulear Excitatory Interactions.

Prenatally malnourished rats develop hypertension in adulthood, in part through increased α-adrenoceptor-mediated outflow from the paraventricular nucleus (PVN) to the sympathetic system. We studied whether both α-adrenoceptor-mediated noradrenergic excitatory pathways from the locus coeruleus (LC) to the PVN and their reciprocal excitatory CRFergic connections contribute to prenatal undernutrition-induced hypertension. For that purpose, we microinjected either α-adrenoceptor or CRH receptor agonists and/or antagonists in the PVN or the LC, respectively.

Early postnatal environmental enrichment restores neurochemical and functional plasticities of the cerebral cortex and improves learning performance in hidden-prenatally-malnourished young-adult rats.

Moderate reduction of dietary protein (from 25% to 8% casein) in pregnant rats, calorically compensated by carbohydrates, gives rise to 'hidden prenatal malnutrition' (HPM) in the offspring since it does not alter body and brain weights of pups at birth. However, this dietary treatment leads to decreased β-adrenoceptor signaling and brain derived neurotrophic factor (BDNF) levels in the pup' brain, altogether with defective cortical long-term potentiation (LTP) and lowered visuospatial memory performance. Since early postnatal environmental enrichment (EE) has been shown to exert plastic effects on the developing brain and neuroprotection both on cognition and on structural properties of the neocortex, in the present study we addressed the question of whether early postnatal EE during the lactation period could exert compensatory changes in the expression of ®-adrenergic receptors and BDNF in the neocortex of HPM rats, and if these effects are associated with an improvement or even a restore of both neocortical LTP in vivo and cognitive performance induced by HPM.

Effect of modafinil on learning performance and neocortical long-term potentiation in rats.

Modafinil is a novel wake-promoting agent whose effects on cognitive performance have begun to be addressed at both preclinical and clinical level. The present study was designed to investigate in rats the effects of chronic modafinil administration on cognitive performance by evaluating: (i) working and reference memories in an Olton 4×4 maze, and (ii) learning of a complex operant conditioning task in a Skinner box. In addition, the effect of modafinil on the ability of the rat frontal cortex to develop long-term potentiation (LTP) was also studied.