Search results for "oio"

A laser desorption/resonance enhanced photoionisation TOF-system for the spatially resolved trace analysis of elements

2004

Abstract A novel method for direct and spatially resolved elemental trace analysis with high sensitivity and elemental selectivity is presented. The concept is based on the combination of a commercial MALDI-TOF mass spectrometer with a pulsed laser system for resonant postionisation of neutrals. While the MALDI method is usually applied for investigations of large organic compounds and biomolecules, the technique discussed here concerns the low mass range around 1 ⩽ A ⩽ 300. The analytical performances of the setup with respect to mass analysis, spatial resolution and overall detection efficiency are discussed.

Effects of scopolamine on dopamine neurons in the substantia nigra : role of the pedunculopontine tegmental nucleus

2009

Previous neurochemical and behavioral studies suggest that muscarinic receptor antagonism has an excitatory effect on the nigrostriatal dopamine (DA) system. Using in vivo extracellular single unit recording, this study examined whether blockade of the muscarinic receptor by scopolamine alters the firing properties of DA neurons in the substantia nigra (SN). Scopolamine was administered either systemically or locally to DA neurons using microiontophoresis. Surprisingly, scopolamine did not cause any significant change in either the firing rate or pattern of the spontaneously active DA neurons. However, systemic injection of scopolamine significantly increased the number of active DA neurons…

Nitric oxide-active compounds modulate the intensity of glutamate-evoked responses in the globus pallidus of the rat

2011

Abstract Aim The effects of local applied NO-active compounds on glutamate (GLU)-evoked responses were investigated in globus pallidus (GP) neurons. Main methods Extracellularly recorded single units from anesthetized rats were treated with GLU before and during the microiontophoretic application of S-nitrosoglutathione (SNOG), a NO donor, and Nω-nitro- l -arginine methyl ester (L-NAME), a NOS inhibitor. Key findings Most GP cells were excited by SNOG whereas administration of L-NAME induced decrease of GP neurons activity. Nearly all neurons responding to SNOG and/or L-NAME showed significant modulation of their excitatory responses to the administration of iontophoretic GLU. In these cell…

Modulation of in vivo GABA-evoked responses by nitric oxide-active compounds in the globus pallidus of rat.

2012

Nitric oxide (NO) is a gaseous molecule acting as a messenger in both the peripheral and the central nervous systems. NO affects synaptic activity by modulating neurotransmitter release and/or receptor function. We previously observed that NO-active compounds modify the bioelectric activity of basal ganglia (BG) units. In this study, we applied microiontophoresis to extracellular in vivo recordings to investigate the effect of NO-active compounds on GABA-evoked responses in the globus pallidus (GP) of anesthetized rats. The changes induced by NO-active drugs on the GABA-induced inhibition were used as indicators of NO modulation. The response to GABA release was tested on recorded GP neuron…

Indicaxanthin from Opuntia ficus-indica Crosses the Blood–Brain Barrier and Modulates Neuronal Bioelectric Activity in Rat Hippocampus at Dietary-Con…

2015

Indicaxanthin is a bioactive and bioavailable betalain pigment from the Opuntia ficus-indica fruits. In this in vivo study, kinetic measurements showed that indicaxanthin is revealed in the rat brain within 1 h from oral administration of 2 μmol/ kg, an amount compatible with a dietary consumption of cactus pear fruits in humans. A peak (20 ± 2.4 ng of indicaxanthin per whole brain) was measured after 2.5 h; thereafter the molecule disappeared with first order kinetics within 4 h. The potential of indicaxanthin to affect neural activities was in vivo investigated by a microiontophoretic approach. Indicaxanthin, administered in a range between 0.085 ng and 0.34 ng per neuron, dose-dependentl…

Treatment of hyperthyroidism with radioiodine targeted activity: A comparison between two dosimetric methods.

2016

Radioiodine therapy is an effective and safe treatment of hyperthyroidism due to Graves' disease, toxic adenoma, toxic multinodular goiter. We compared the outcomes of a traditional calculation method based on an analytical fit of the uptake curve and subsequent dose calculation with the MIRD approach, and an alternative computation approach based on a formulation implemented in a public-access website, searching for the best timing of radioiodine uptake measurements in pre-therapeutic dosimetry. We report about sixty-nine hyperthyroid patients that were treated after performing a pre-therapeutic dosimetry calculated by fitting a six-point uptake curve (3-168h). In order to evaluate the res…

Nitric oxide- and cGMP-active compounds affect the discharge of substantia nigra pars reticulata neurons: in vivo evidences in the rat

2009

The nitric oxide (NO)-active drugs influence on the bioelectric activity of neurons of the pars reticulata of the substantia nigra was studied in urethane-anesthetized rats. A first group of animals was treated with 7-nitro-indazole (7-NI), a preferential inhibitor of neuronal NO synthase. In a second group of rats, electrophysiological recordings were coupled with microiontophoretic administration of Nomega-nitro-L-arginine methyl ester (L-NAME, a NO synthase inhibitor), 3-morpholino-sydnonimin-hydrocloride (SIN-1, a NO donor) and 8-Br-cGMP (a cell-permeable analogue of cGMP, the main second-messenger of NO neurotransmission). 7-NI and L-NAME caused a statistically significant decrease in …

Molecular and functional interactions between tumor necrosis factor-alpha receptors and the glutamatergic system in the mouse hippocampus: Implicatio…

2009

Tumor necrosis factor (TNF)-alpha is a proinflammatory cytokine acting on two distinct receptor subtypes, namely p55 and p75 receptors. TNF-alpha p55 and p75 receptor knockout mice were previously shown to display a decreased or enhanced susceptibility to seizures, respectively, suggesting intrinsic modifications in neuronal excitability. We investigated whether alterations in glutamate system function occur in these naive knockout mice with perturbed cytokine signaling that could explain their different propensity to develop seizures. Using Western blot analysis of hippocampal homogenates, we found that p55(-/-) mice have decreased levels of membrane GluR3 and NR1 glutamate receptor subuni…

Gozos a la gloriosa Santa Marta , patrona de la villa de Villajoyosa.

El full orlat Grav. xil. enmarcat de la santa, flanquejat per gerros amb flors El text del goig a tres col. separades per filets

Binding site of different tannins on a human salivary proline-rich protein evidenced by dissociative photoionization tandem mass spectrometry

2015

Abstract The sensation of astringency is thought to originate from the interaction occurring between tannins and the salivary proline-rich proteins (PRPs). Astringency perception can be modified by the structure of tannins. Herein, we study the interactions occurring between the human salivary PRP, IB5, and three model tannins with different structure, epigallocatechin gallate and the procyanidin dimers B2 and B2 3′ O -gallate, using the coupling of mass spectrometry and VUV-synchrotron radiation. The results obtained indicate that the structure of tannins, in particular the degree of polymerization and the galloylation, does not modify the binding site on IB5 involved in the interaction.