OPERA: a novel method to reduce ghost and aliasing artifacts.

Objective: A method for Orthogonal Phase Encoding Reduction of Artifact (OPERA) was developed and tested.

Materials And Methods: Because the position of ghosts and aliasing artifacts is predictable along columns or rows, OPERA combines the intensity values of two images acquired using the same parameters, but with swapped phase-encoding directions, to correct the artifacts. Simulations and phantom experiments were conducted to define the efficacy, robustness, and reproducibility.

Treatment with CCR2 antagonist is neuroprotective but does not alter epileptogenesis in the pilocarpine rat model of epilepsy.

Neuroinflammation role on epileptogenesis has been the subject of increasing interest. Many studies showed elevation in cytokines and chemokines expression following seizures, such as, CCL2 protein (C-C motif ligand 2 chemokine) and its specific receptor, CCR2. In addition, recent studies manipulating the CCL2/CCR2 complex verified improved seizure outcome in different seizure models.

Increased CCL2, CCL3, CCL5, and IL-1β cytokine concentration in piriform cortex, hippocampus, and neocortex after pilocarpine-induced seizures.

Background: Cytokines and chemokines play an important role in the neuroinflammatory response to an initial precipitating injury such as status epilepticus (SE). These signaling molecules participate in recruitment of immune cells, including brain macrophages (microglia), as well as neuroplastic changes, deterioration of damaged tissue, and epileptogenesis. This study describes the temporal and brain region pattern expression of numerous cytokines, including chemokines, after pilocarpine-induced seizures and discusses them in the larger context of their potential involvement in the changes that precede the development of epilepsy.

Nervous and immune systems signals and connections: cytokines in hippocampus physiology and pathology.

Signaling through secretion of small molecules is a hallmark of both nervous and immune systems. The scope and influence of the intense message exchange between these two complex systems are only now becoming objects of scientific inquiry. Both neurotransmitters and cytokines affect their target cells through surface receptors and also by other molecular mechanisms.

Elucidating the neurotoxicity of the star fruit.

Caramboxin: Patients suffering from chronic kidney disease are frequently intoxicated after ingesting star fruit. The main symptoms of this intoxication are named in the picture. Bioguided chemical procedures resulted in the discovery of caramboxin, which is a phenylalanine-like molecule that is responsible for intoxication.

Morphological alterations in newly born dentate gyrus granule cells that emerge after status epilepticus contribute to make them less excitable.

Computer simulations of external current stimulations of dentate gyrus granule cells of rats with Status Epilepticus induced by pilocarpine and control rats were used to evaluate whether morphological differences alone between these cells have an impact on their electrophysiological behavior. The cell models were constructed using morphological information from tridimensional reconstructions with Neurolucida software. To evaluate the effect of morphology differences alone, ion channel conductances, densities and distributions over the dendritic trees of dentate gyrus granule cells were the same for all models.

Astrocyte Alterations in the Hippocampus Following Pilocarpine-induced Seizures in Aged Rats.

It is known that the incidence of epilepsy increases with age, but only a few studies have investigated the consequences and mechanisms of seizure and epilepsy in aged animals. Astrocytic changes are known to directly influence neuronal excitability and seizure susceptibility. However, information regarding alterations to astrocytes after seizures in aged animals is lacking in the literature.

The role of olfactory stimulus in adult mammalian neurogenesis.

Neurogenesis occurs in the adult mammalian brain in discrete regions related to olfactory sensory signaling and integration. The olfactory receptor cell population is in constant turn-over through local progenitor cells. Also, newborn neurons are added to the olfactory bulbs through a major migratory route from the subventricular zone, the rostral migratory stream.

Comparison of effectiveness of carvedilol versus bisoprolol for prevention of postdischarge atrial fibrillation after coronary artery bypass grafting in patients with heart failure.

Atrial fibrillation (AF) occurs frequently soon after coronary artery bypass grafting (CABG) and often results in increased mortality and morbidity, particularly in patients with heart failure. New-onset AF is also a common event in the early period after discharge from a cardiac surgery clinic. Current guidelines recommend β blockers as first-line medication for the prevention of AF after CABG.

Role of glia in epilepsy-associated neuropathology, neuroinflammation and neurogenesis.

The black reaction allowed Golgi to describe with amazing detail the morphology of glial cells as well as their proximal location and intimate connections with neurons and blood vessels. Based on this location, Golgi hypothesized that glial cells were functional units in the nervous system and were not merely a structural support medium. Relatively recent advances have confirmed the importance of glial cells in nervous system function and disease.

Morphological and ultrastructural features of Iba1-immunolabeled microglial cells in the hippocampal dentate gyrus.

Microglia are found throughout the central nervous system, respond rapidly to pathology and are involved in several components of the neuroinflammatory response. Iba1 is a marker for microglial cells and previous immunocytochemical studies have utilized this and other microglial-specific antibodies to demonstrate the morphological features of microglial cells at the light microscopic level. However, there is a paucity of studies that have used microglial-specific antibodies to describe the ultrastructural features of microglial cells and their processes.

Evidence of early involvement of matrix metalloproteinase-2 in lead-induced hypertension.

Lead exposure increases blood pressure (BP) by unknown mechanisms. Many recent studies have shown the involvement of matrix metalloproteinases (MMPs) in hypertension, particularly MMP-2. In this work, we have examined whether MMP-2 levels increase with lead-induced increase in BP.

Chelatable zinc modulates excitability and seizure duration in the amygdala rapid kindling model.

Zinc is present in high concentration in many structures of the limbic circuitry, however the role of zinc as a neuromodulator in such synapses is still uncertain. In this work, we verified the effects of zinc chelation in an animal model of epileptogenesis induced by amygdala rapid kindling. The basolateral amygdala was electrically stimulated ten times per day for 2 days.

Doublecortin-positive newly born granule cells of hippocampus have abnormal apical dendritic morphology in the pilocarpine model of temporal lobe epilepsy.

Here, we describe dentate gyrus newly born granule cells morphology in rats' temporal lobe epilepsy pilocarpine model. Digital reconstruction of doublecortin-positive neurons revealed that apical dendrites had the same total length and number of nodes in epileptic and control animals. Nonetheless, concentric spheres analyses revealed that apical dendrites spatial distribution was radically altered in epileptic animals.

Plasticity, synaptic strength, and epilepsy: what can we learn from ultrastructural data?

Central nervous system synapses have an intrinsic plastic capacity to adapt to new conditions with rapid changes in their structure. Such activity-dependent refinement occurs during development and learning, and shares features with diseases such as epilepsy. Quantitative ultrastructural studies based on serial sectioning and reconstructions have shown various structural changes associated with synaptic strength involving both dendritic spines and postsynaptic densities (PSDs) during long-term potentiation (LTP).

Correlation between shaking behaviors and seizure severity in five animal models of convulsive seizures.

Wet dog shakes (WDS) and head shakes (HS) are associated with experimentally induced convulsive seizures. We sought to determine whether these behaviors are correlated or not with major (status epilepticus (SE) or fully kindled animals) or minor (non-SE or partially kindled animals) seizure severity. WDS are directly correlated with SE induced by intracerebral star fruit extract (Averrhoa carambola) injection and with kindled animals in the amygdala fast kindling model.

[Prevention of post-ERCP acute pancreatitis with octreotide].

Acute pancreatitis is one of the most serious complications in endoscopic cholangio-pancreatography (ERCP) and endoscopic sphincterotomy (EPT). Many attempts to avoid such complication have proved to be unsuccessful. The aim of this study was to evaluate the therapeutic effect of octreotide acetate in preventing acute pancreatitis following ERCP.

Epicardial excitation during ventricular pacing. Relative independence of breakthrough sites from excitation sequence in canine right ventricle.

In a previous investigation, epicardial recordings with 1,124 closely spaced electrodes revealed 20-35 breakthrough (BKT) sites and an equal number of separate wave fronts on the ventricular surface of exposed dog hearts during normal sinus rhythm. In the present study we tried 1) to determine whether ventricular pacing also produced multiple BKTs and wave fronts and 2) to determine whether the number and location of BKTs were, to some degree, independent of pacing site. The study mainly focused on right ventricular BKTs observed during right ventricular pacing.

A new intracavitary probe for detecting the site of origin of ectopic ventricular beats during one cardiac cycle.

An olive-shaped probe (25 X 12 mm) with 41 evenly distributed recording electrodes on its surface was introduced into the left ventricles of seven open-chest dogs via the left atrium. In two other dogs a cylindrical probe (40 X 3 mm) was used. Electrical stimuli were delivered at 66 endocardial, midwall, or epicardial sites in the left and right ventricular walls and the septum.

The effect of cardiac electric anisotropy on epicardial potential fields during ventricular repolarization.

We tried to establish whether some of the manifestations of electrical anisotropy previously observed on the canine ventricular epicardium during the spread of excitation were also present during repolarization, with the appropriate polarity. To this end we determined the potential distribution on the ventricular surface of exposed dog hearts during ventricular excitation and repolarization. The ventricles were paced by means of epicardial or intramural electrodes.