Within 2 min of stroke onset, neurons and glia in brain regions most deprived of blood (the ischemic core) undergo a sudden and profound loss of membrane potential caused by failure of the Na+/K+ ATPase pump. This anoxic depolarization (AD) represents a collapse in membrane ion selectivity that causes acute neuronal injury because neurons simply cannot survive the energy demands of repolarization while deprived of oxygen and glucose. In vivo and in live brain slices, the AD resists blockade by antagonists of neurotransmitter receptors (including glutamate) or by ion channel blockers. Our neuroprotective strategy is to identify AD blockers that minimally affect neuronal function. If the conductance underlying AD is not normally active, its selective blockade should not alter neuronal excitability. Imaging changes in light transmittance in live neocortical and hippocampal slices reveal AD onset, propagation, and subsequent dendritic damage. Here we identify several sigma-1 receptor ligands that block the AD in slices that are pretreated with 10-30 microM of ligand. Blockade prevents subsequent cell swelling, dendritic damage, and loss of evoked field potentials recorded in layers II/III of neocortex and in the CA1 region of hippocampus. Even when AD onset is merely delayed, electrophysiological recovery is markedly improved. With ligand treatment, evoked axonal conduction and synaptic transmission remain intact. The large nonselective conductance that drives AD is still unidentified but represents a prime upstream target for suppressing acute neuronal damage arising during the first critical minutes of stroke. Sigma receptor ligands provide insight to better define the properties of the channel responsible for anoxic depolarization. Video clips of anoxic depolarization and spreading depression can be viewed at http://anatomy.queensu.ca/faculty/andrew.cfm.

Background: Despite a high prevalence of mild gastroesophageal reflux disease (GERD), few studies investigated efficacy and safety of proton pump inhibitors in this indication. This randomized double-blind study compares pantoprazole to ranitidine in GERD 0 and I, i.e. reflux without esophagitis or with confined lesions only. Methods: Patients received either pantoprazole 20 mg o.a.d. or ranitidine 150 mg b.i.d. Outcome was assessed after 2 and 4 weeks. Primary criterion was relief of leading symptoms, i.e. heartburn, acid eructation and pain on swallowing, after 4 weeks of treatment. Results: According to the per-protocol (PP) analysis, 69% (100/144) and 80% (115/144) of patients in the pantoprazole group were relieved of leading symptoms after 2 and 4 weeks, respectively. The rates in the ranitidine group were 47% (62/133) and 65% (86/133). Thus, superiority of pantoprazole could be proven. Quality-of-life parameters improved more in the pantoprazole group and patients’ assessment of treatment was more favorable. Analysis for Helicobacter pylori status showed infection to lead to higher symptom relief rates. Both study medications were well tolerated. Conclusion: Pantoprazole 20 mg demonstrated superior efficacy with faster relief of reflux symptoms and similar tolerability compared to ranitidine 150 mg in the treatment of mild GERD.

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