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Perinatal asphyxia is characterized by oxygen deprivation and lack of perfusion in the perinatal period, leading to hypoxic-ischemic encephalopathy and sequelae such as cerebral palsy, mental retardation, cerebral visual impairment, epilepsy and learning disabilities. On cellular level PA is associated with a decrease in oxygen and glucose leading to ATP depletion and a compromised mitochondrial function. Upon reoxygenation and reperfusion, the renewed availability of oxygen gives rise to not only restoration of cell function, but also to the activation of multiple detrimental biochemical pathways, leading to secondary energy failure and ultimately, cell death. The formation of reactive oxygen species, nitric oxide and peroxynitrite plays a central role in the development of subsequent neurological damage. In this review we give insight into the pathophysiology of perinatal asphyxia, discuss its clinical relevance and summarize current neuroprotective strategies related to therapeutic hypothermia, ischemic postconditioning and pharmacological interventions. The review will also focus on the possible neuroprotective actions and molecular mechanisms of the selective neuronal and inducible nitric oxide synthase inhibitor 2-iminobiotin that may represent a novel therapeutic agent for the treatment of hypoxic-ischemic encephalopathy, both in combination with therapeutic hypothermia in middle- and high-income countries, as well as stand-alone treatment in low-income countries. Image 1 • In this review the pathophysiology of perinatal asphyxia is discussed. • Neuroprotective strategies near or in clinical trials are discussed and summarized. • Special focus is on the selective neuronal and inducible NOS inhibitor 2-iminobiotin. [ABSTRACT FROM AUTHOR]

Several animal models have been used to simulate cerebral hypoxia-ischemia and suggested neuroprotective effects of the biotin analogue 2-iminobiotin (2-IB). The aims of this study were to employ a human in-vitro hypoxia model to confirm protective effects of 2-IB on neuronal cells, determine the optimal neuroprotective concentrations of 2-IB and scrutinize underlying cellular effects of 2-IB. Neuronal IMR-32 cells were exposed to hypoxia employing an enzymatic hypoxia system and were thereafter incubated with various concentrations of 2-IB (10 to 300ng/ml). Cell damage, metabolic activity and generation of reactive oxygen species were quantified using colorimetric/fluorometric lactate dehydrogenase (LDH), tetrazolium-based (MTS) and reactive oxygen species assays. Proteome profiling arrays were performed to evaluate the regulation of cell stress protein expression by hypoxia and 2-IB. Seven hours of hypoxia led to morphological changes in IMR-32 cultures, increased neuronal cell damage (P<0.001), reduction of metabolic activity (P<0.01) and enhanced reactive oxygen species production (P<0.05). Post-hypoxic application of 2-IB (30ng/ml) attenuated hypoxia-induced LDH release (P<0.05) and increased metabolic activity of IMR-32 cells (P<0.05), while reactive oxygen species production was only by trend decreased. Array-based protein expression profiling revealed that 2-IB attenuated the expression of several hypoxia-induced cell stress-associated proteins by more than 25% (pp38α, HIF2α, ADAMTS1, pHSP27, PON2, PON3 and p27). Hypoxia-induced neuronal cell damage can be simulated using the described in-vitro model. 2-IB inhibits hypoxia-mediated neurotoxicity most efficiently at 30 ng/ml and the underlying mechanisms involve a downregulation of stress-associated protein expression. Our results suggest 2-IB as a potential drug for the treatment of perinatal hypoxia-ischemia. [ABSTRACT FROM AUTHOR]

Hydroxyethyl starch (HES) is employed to sustain normovolemia in patients. Using a perfused organ model, we recently showed that HES impairs the intestinal barrier which is constituted of endothelial and epithelial cell layers. However, the target cells and molecular actions of HES in the intestine are mainly unknown. Employing a model of human endothelial (HUVEC) and intestinal epithelial cells (Caco-2), we investigated the impact of HES, albumin and HES/albumin on cellular integrity/permeability and evaluated underlying molecular mechanisms. Monolayers of HUVEC and Caco-2 were cultured with HES (3%), albumin (3%) or HES/albumin (1.5%/1.5%). Integrity and permeability of the cell layers were evaluated by FITC-dextran transfer, measurements of cell detachment, vitality, cell volume, LDH release and caspase-3/7 activity. Cellular mechanisms were analyzed by Westernblotting for P-akt, P-erk, claudin-3 and I-FABP. HES application resulted in higher numbers of non-adherent/floating HUVEC cells (P<0.05) but did not change vitality or cell volume. Both, HES and HES/albumin increased the permeability of HUVEC monolayers (P<0.001), while LDH release, caspase-3/7 activity, akt/erk phosphorylation and claudin-3 expression were not affected. HES and HES/albumin did not change any of the parameters in cultures of Caco-2 cells. HES is able to disturb the integrity of the endothelial but not the epithelial barrier in vitro. HES effects are unrelated to cell damage and apoptosis but may involve reduced cell-cell or cell-matrix adhesion. • Hydroxyethylstarch (HES) containing solutions are employed to sustain normovolemia in patients. • We have recently shown that HES impairs the intestinal barrier integrity in a perfused organ model. • Employing human endothelial and epithelial cells we investigated the impact of HES on cellular integrity/permeability. • Clinically relevant concentrations of HES disturb the integrity of the endothelial but not the epithelial barrier. • HES effects are unrelated to cell damage and apoptosis but may involve reduced cell-cell or cell-matrix adhesion. [ABSTRACT FROM AUTHOR]

Abstract: Aim of the study: Successful resuscitation after cardiac arrest is typically associated with cerebral and myocardial ischemia/reperfusion (I/R)-injury. Recently, we have demonstrated effects of therapeutic hypothermia (HT) and postconditioning with the volatile anesthetic sevoflurane (SEV) on I/R-mediated mechanisms in the heart and brain [Meybohm et al., PLoS One, 2009; Meybohm et al., Crit Care, 2010]. As the intestine is also highly susceptible to I/R-injury, we investigated the influence of HT and SEV on intestinal I/R-mediated events induced by cardiac arrest and successful resuscitation. Methods: Effects of I/R, HT (12h, 33°C) and a combination of HT with SEV (12h, 2.0vol%) were evaluated in a pig model of cardiac arrest and successful cardiopulmonary resuscitation. Western blotting, ELISA, caspase-3/7 assays, myeloperoxidase (MPO) quantifications and gelatine zymography were performed using intestinal tissue derived 24h after return of spontaneous circulation. Results: Compared to the normothermia control, HT and HT+SEV resulted in a significant increase in intestinal HIF-1α protein expression (P <0.05). Tissue concentrations of IL-1β were significantly reduced in the HT and HT+SEV group (P <0.05), whereas a reduction of IL-10 levels was only detected in the intestine of animals treated with HT+SEV (P <0.05). A statistically significant increase of intestinal MPO activity was found in the HT+SEV group (P <0.01). Activities of caspase-3 and 7 or matrixmetalloproteinase-2 were not changed in any of the groups investigated, the activity of matrixmetalloproteinase-9 was, however, significantly increased in the HT+SEV group (P <0.05). Conclusion: HT and postconditioning with SEV influence the expression and activity of several small intestinal proteins that are possibly involved in intestinal I/R-mediated events following successful cardiopulmonary resuscitation. [Copyright &y& Elsevier]

Abstract: Early embryonic development is critically dependent on both maternal preparation and embryonic signalling of pregnancy. Matrix metallopeptidases (MMP) contribute to spatial and temporal matrix remodeling in the bovine endometrium. In this study we observed distinct changes in expression of MMP2, MMP14, and the metallopeptidase inhibitor TIMP2 between different phases of the estrous cycle indicating an endocrine regulation. An increase of TIMP2 protein abundance was ascertained in the uterine lumen during the time of embryo elongation. The expression pattern and cellular localization correlate well with the assumed effects of MMPs on release and activation of cytokines and growth factors directing cell migration, differentiation, and vascularization during this pivotal period of development. Specifically, active MMP2 in the endometrium may determine the allocation of growth factors supporting conceptus development. The presence of a day 18 conceptus in vivo and day 8 blastoysts in vitro induced endometrial TIMP2 mRNA expression. The results imply that TIMP2 is involved in very early local maternal recognition of pregnancy. Matrix metallopeptidases are likely to participate in remodeling processes preparing a receptive endometrium for a timely and precise regulation of embryo development. [Copyright &y& Elsevier]

Background Remote ischaemic post-conditioning (RIPoC) in which transient episodes of ischaemia (e.g. by inflation and deflation of a blood pressure cuff) are applied after a prolonged ischaemia/reperfusion injury, may have the potential to improve patient outcome and survival following cardiac arrest. In this study we employed a pig model of cardiac arrest and successful cardiopulmonary resuscitation to evaluate the effects of RIPoC on haemodynamics, cardiac tissue damage and neurologic deficit. Materials and methods A total of 22 pigs were subjected to ventricular fibrillation, cardiopulmonary resuscitation and randomly assigned to Control or RIPoC treatment consisting of 4 cycles of 5 min femoral artery occlusion followed by 5 min of reperfusion starting 10 min after return of spontaneous circulation (ROSC). Post-resuscitation was evaluated by haemodynamics using left ventricular conductance catheters, quantification of cardiac troponin T (cTnT), lactate dehydrogenase (LDH) and creatine kinase (CK). Neurological testing was performed 24 h after return of spontaneous circulation (ROSC). Results RIPoC resulted in a statistically significant reduction of serum cTnT levels 4 h after ROSC ( P ≤ 0.01). LDH and CK concentrations were significantly lower in RIPoC treated pigs 24 h after ROSC ( P ≤ 0.001), suggesting tissue and/or cardioprotective effects of RIPoC. End-systolic pressure volume relationship was significantly increased in RIPoC treated animals 4 h after ROSC ( P ≤ 0.05). Neurological testing revealed a trend towards an improved outcome in RIPoC treated animals. Conclusions We propose that RIPoC applied immediately after ROSC reduces serum concentrations of markers for cell damage and improves end-systolic pressure volume relationship 4 h after ROSC. [ABSTRACT FROM AUTHOR]