Antioxidant Enzyme-Mimetic Activity and Neuroprotective Effects of Cerium Oxide Nanoparticles Stabilized with Various Ratios of Citric Acid and EDTA.

Cerium oxide (CeO) nanoparticles (CeNPs) are potent antioxidants that are being explored as potential therapies for diseases in which oxidative stress plays an important pathological role. However, both beneficial and toxic effects of CeNPs have been reported, and the method of synthesis as well as physico-chemical, biological, and environmental factors can impact the ultimate biological effects of CeNPs. In the present study, we explored the effect of different ratios of citric acid (CA) and EDTA (CA/EDTA), which are used as stabilizers during synthesis of CeNPs, on the antioxidant enzyme-mimetic and biological activity of the CeNPs.

Trpv4 Mediates Hypotonic Inhibition of Central Osmosensory Neurons via Taurine Gliotransmission.

The maintenance of hydromineral homeostasis requires bidirectional detection of changes in extracellular fluid osmolality by primary osmosensory neurons (ONs) in the organum vasculosum laminae terminalis (OVLT). Hypertonicity excites ONs in part through the mechanical activation of a variant transient receptor potential vanilloid-1 channel (dn-Trpv1). However, the mechanism by which local hypotonicity inhibits ONs in the OVLT remains unknown.

Early Brain Edema is a Predictor of In-Hospital Mortality in Traumatic Brain Injury.

Background: Identifying patients who may progress to a poor clinical outcome will encourage earlier appropriate therapeutic interventions. Brain edema may contribute to secondary injury in traumatic brain injury (TBI) and thus, may be a useful prognostic indicator.

Objective: We determined whether the presence of brain edema on the initial computed tomography (CT) scan of TBI patients would predict poor in-hospital outcome.

Intranasal naloxone administration by police first responders is associated with decreased opioid overdose deaths.

Objective: This study sought to answer the question, "Can police officers administer intranasal naloxone to drug overdose victims to decrease the opioid overdose death rate?"

Methods: This prospective interventional study was conducted in Lorain County, OH, from January 2011 to October 2014. Starting October 2013, trained police officers administered naloxone to suspected opioid overdose victims through a police officer naloxone prescription program (NPP). Those found by the county coroner to be positive for opioids at the time of death and those who received naloxone from police officers were included in this study.

Angiotensin converting enzyme 2/Ang-(1-7)/mas axis protects brain from ischemic injury with a tendency of age-dependence.

Background: The angiotensin (Ang) converting enzyme 2 (ACE2)/Ang-(1-7)/Mas receptor pathway is an important component of the renin-angiotensin system and has been suggested to exert beneficial effects in ischemic stroke.

Aims: This study explored whether the ACE2/Ang-(1-7)/Mas pathway has a protective effect on cerebral ischemic injury and whether this effect is affected by age.

Methods: We used three-month and eight-month transgenic mice with neural over-expression of ACE2 (SA) and their age-matched nontransgenic (NT) controls.

Taurine release by astrocytes modulates osmosensitive glycine receptor tone and excitability in the adult supraoptic nucleus.

Cells can release the free amino acid taurine through volume-regulated anion channels (VRACs), and it has been hypothesized that taurine released from glial cells is capable of inhibiting action potential (AP) firing by activating neuronal glycine receptors (GlyRs) (Hussy et al., 1997). Although an inhibitory GlyR tone is widely observed in the brain, it remains unknown whether this specifically reflects gliotransmission because most neurons also express VRACs and other endogenous molecules can activate GlyRs.

Glutamate receptor-mediated taurine release from the hippocampus during oxidative stress.

Background: Hippocampal slices swell and release taurine during oxidative stress. The influence of cellular signalling pathways on this process is unclear. Glutamate signalling can facilitate volume regulation in other CNS preparations.

Ischemia-induced brain damage is enhanced in human renin and angiotensinogen double-transgenic mice.

To investigate the role of brain angiotensin II (ANG II) in the pathogenesis of injury following ischemic stroke, mice overexpressing renin and angiotensinogen (R+A+) and their wild-type control animals (R-A-) were used for experimental ischemia studies. Focal brain ischemia was induced by middle cerebral artery occlusion (MCAO). The severity of ischemic injury was determined by measuring neurological deficits and histological damage at 24 and 48 h after MCAO, respectively.

Purinergic activation of anion conductance and osmolyte efflux in cultured rat hippocampal neurons.

The majority of mammalian cells demonstrate regulatory volume decrease (RVD) following swelling caused by hyposmotic exposure. A critical signal initiating RVD is activation of nucleotide receptors by ATP. Elevated extracellular ATP in response to cytotoxic cell swelling during pathological conditions also may initiate loss of taurine and other intracellular osmolytes via anion channels.

Physiologic effects of simulated + Gx orbital reentry in primate models of hemorrhagic shock.

Introduction: While the physiologic effects of space travel are documented in healthy individuals, little is known about its impact on medically ill or injured persons. In this study, hemorrhagic shock in primates was used to model a potentially common pathophysiologic condition during exposure to gravitational forces simulating return from Earth orbit. This experiment did not model the effects of cardiovascular deconditioning that normally occur during spaceflight.

Regulation of taurine transport in rat hippocampal neurons by hypo-osmotic swelling.

Taurine, an important mediator of cellular volume regulation in the central nervous system, is accumulated into neurons and glia by means of a highly specific sodium-dependent membrane transporter. During hyperosmotic cell shrinkage, net cellular taurine content increases as taurine transporter activity is enhanced via elevated gene expression of the transporter protein. In hypo-osmotic conditions, taurine is rapidly lost from cells by means of taurine-conducting membrane channels.

Altitude decompression sickness symptom resolution during descent to ground level.

Introduction: Altitude decompression sickness (DCS) is a health risk associated with the conduct of high altitude airdrop operations, high altitude reconnaissance, future fighter operations, hypobaric chamber training, unpressurized flight, and extravehicular activity (EVA) in space. The treatment for DCS includes the provision of 100% oxygen (O2) at ground level (GLO) and/or hyperbaric oxygen therapy (HBO). In this paper we examine the effect of repressurization to ground level from hypobaric conditions on DCS symptoms.

Volume-regulated anion conductance in cultured rat cerebral astrocytes requires calmodulin activity.

We examined the calmodulin dependence of anion channel activation during hypo-osmotic swelling in rat cerebral astrocytes. Control cells bathed in iso-osmotic (290 mOsm) phosphate-buffered saline (PBS) and recorded using a patch electrode containing 140 mM KCl increased membrane conductance threefold over basal levels after 12 min in hypo-osmotic (200 mOsm) PBS. Cells injected with monoclonal anticalmodulin antibody demonstrated no increase in membrane conductance during a subsequent exposure to hypo-osmotic PBS.

Extracellular ATP activates chloride and taurine conductances in cultured hippocampal neurons.

We investigated regulation by extracellular ATP of channels important for volume regulation of rat hippocampal neurons. Cultures made from fetuses at the eighteenth gestational day were predominantly neuronal after 10-20 days in vitro, as indicated by immunostaining for neuron specific enolase. Neurons recorded with whole-cell patch clamp showed inward currents when membrane voltages were driven to values greater than -50 mV.

Calcium/calmodulin-modulated chloride and taurine conductances in cultured rat astrocytes.

Osmotically swollen rat cerebral astrocytes develop an increased anion conductance which can mediate chloride and taurine release. We used whole cell patch clamp to study mechanisms that modulate this conductance. Astrocyte chloride conductance increased within 4 min of exposure to 200 mOsm medium and was 670+/-123% of its initial value after 15 min (mean+/-S.