Regulation of dopamine synthesis and release in striatal and prefrontal cortical brain slices

International Nuclear Information System (INIS)

Wolf, M.E.

1986-01-01

Brain slices were used to investigate the role of nerve terminal autoreceptors in modulating dopamine (DA) synthesis and release in striatum and prefrontal cortex. Accumulation of dihydroxyphenylalanine (DOPA) was used as an index of tyrosine hydroxylation in vitro. Nomifensine, a DA uptake blocker, inhibited DOPA synthesis in striatal but not prefrontal slices. This effect was reversed by the DA antagonist sulpiride, suggesting it involved activation of DA receptors by elevated synaptic levels of DA. The autoreceptor-selective agonist EMD-23-448 also inhibited striatal but not prefrontal DOPA synthesis. DOPA synthesis was stimulated in both brain regions by elevated K + , however only striatal synthesis could be further enhanced by sulpiride. DA release was measured by following the efflux of radioactivity from brain slices prelabeled with [ 3 H]-DA. EMD-23-448 and apomorphine inhibited, while sulpiride enhanced, the K + -evoked overflow of radioactivity from both striatal and prefrontal cortical slices. These findings suggest that striatal DA nerve terminals possess autoreceptors which modulate tyrosine hydroxylation as well as autoreceptors which modulate release. Alternatively, one site may be coupled to both functions through distinct transduction mechanisms. In contrast, autoreceptors on prefrontal cortical terminals appear to regulate DA release but not DA synthesis

Microfluidic culture chamber for the long-term perfusion and precise chemical stimulation of organotypic brain tissue slices

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Caicedo, H. H.; Vignes, M.; Brugg, B.

2010-01-01

We have developed a microfluidic perfusion-based culture system to study long-term in-vitro responses of organo-typic brain slices exposed to localized neurochemical stimulation. Using this microperfusion chamber we show that hip-pocampal organotypic brain slices cultures grown on nitrocellulose ...

Evaluation of registration strategies for multi-modality images of rat brain slices

International Nuclear Information System (INIS)

Palm, Christoph; Vieten, Andrea; Salber, Dagmar; Pietrzyk, Uwe

2009-01-01

In neuroscience, small-animal studies frequently involve dealing with series of images from multiple modalities such as histology and autoradiography. The consistent and bias-free restacking of multi-modality image series is obligatory as a starting point for subsequent non-rigid registration procedures and for quantitative comparisons with positron emission tomography (PET) and other in vivo data. Up to now, consistency between 2D slices without cross validation using an inherent 3D modality is frequently presumed to be close to the true morphology due to the smooth appearance of the contours of anatomical structures. However, in multi-modality stacks consistency is difficult to assess. In this work, consistency is defined in terms of smoothness of neighboring slices within a single modality and between different modalities. Registration bias denotes the distortion of the registered stack in comparison to the true 3D morphology and shape. Based on these metrics, different restacking strategies of multi-modality rat brain slices are experimentally evaluated. Experiments based on MRI-simulated and real dual-tracer autoradiograms reveal a clear bias of the restacked volume despite quantitatively high consistency and qualitatively smooth brain structures. However, different registration strategies yield different inter-consistency metrics. If no genuine 3D modality is available, the use of the so-called SOP (slice-order preferred) or MOSOP (modality-and-slice-order preferred) strategy is recommended.

Coupling of organotypic brain slice cultures to silicon-based arrays of electrodes

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Jahnsen, Henrik; Kristensen, Bjarne Winther; Thiébaud, P

1999-01-01

Fetal or early postnatal brain tissue can be cultured in viable and healthy condition for several weeks with development and preservation of the basic cellular and connective organization as so-called organotypic brain slice cultures. Here we demonstrate and describe how it is possible to establish...

Brain Slice Staining and Preparation for Three-Dimensional Super-Resolution Microscopy

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German, Christopher L.; Gudheti, Manasa V.; Fleckenstein, Annette E.; Jorgensen, Erik M.

2018-01-01

Localization microscopy techniques – such as photoactivation localization microscopy (PALM), fluorescent PALM (FPALM), ground state depletion (GSD), and stochastic optical reconstruction microscopy (STORM) – provide the highest precision for single molecule localization currently available. However, localization microscopy has been largely limited to cell cultures due to the difficulties that arise in imaging thicker tissue sections. Sample fixation and antibody staining, background fluorescence, fluorophore photoinstability, light scattering in thick sections, and sample movement create significant challenges for imaging intact tissue. We have developed a sample preparation and image acquisition protocol to address these challenges in rat brain slices. The sample preparation combined multiple fixation steps, saponin permeabilization, and tissue clarification. Together, these preserve intracellular structures, promote antibody penetration, reduce background fluorescence and light scattering, and allow acquisition of images deep in a 30 μm thick slice. Image acquisition challenges were resolved by overlaying samples with a permeable agarose pad and custom-built stainless steel imaging adapter, and sealing the imaging chamber. This approach kept slices flat, immobile, bathed in imaging buffer, and prevented buffer oxidation during imaging. Using this protocol, we consistently obtained single molecule localizations of synaptic vesicle and active zone proteins in three-dimensions within individual synaptic terminals of the striatum in rat brain slices. These techniques may be easily adapted to the preparation and imaging of other tissues, substantially broadening the application of super-resolution imaging. PMID:28924666

Organotypic hippocampal slice culture from the adult mouse brain: a versatile tool for translational neuropsychopharmacology.

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Kim, Hyunjeong; Kim, Eosu; Park, Minsun; Lee, Eun; Namkoong, Kee

2013-03-05

One of the most significant barriers towards translational neuropsychiatry would be an unavailability of living brain tissues. Although organotypic brain tissue culture could be a useful alternative enabling observation of temporal changes induced by various drugs in living brain tissues, a proper method to establish a stable organotypic brain slice culture system using adult (rather than neonatal) hippocampus has been still elusive. In this study, we evaluated our simple method using the serum-free culture medium for successful adult organotypic hippocampal slice culture. Several tens of hippocampal slices from a single adult mouse (3-5 months old) were cultured in serum-free versus serum-containing conventional culture medium for 30 days and underwent various experiments to validate the effects of the existence of serum in the culture medium. Neither the excessive regression of neuronal viability nor metabolic deficiency was observed in the serum-free medium culture in contrast to the serum-containing medium culture. Despite such viability, newly generated immature neurons were scarcely detected in the serum-free culture, suggesting that the original neurons in the brain slice persist rather than being replaced by neurogenesis. Key structural features of in vivo neural tissue constituting astrocytes, neural processes, and pre- and post-synapses were also well preserved in the serum-free culture. In conclusion, using the serum-free culture medium, the adult hippocampal slice culture system will serve as a promising ex vivo tool for various fields of neuroscience, especially for studies on aging-related neuropsychiatric disorders or for high throughput screening of potential agents working against such disorders. Copyright © 2012 Elsevier Inc. All rights reserved.

Dibucaine mitigates spreading depolarization in human neocortical slices and prevents acute dendritic injury in the ischemic rodent neocortex.

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W Christopher Risher

Full Text Available Spreading depolarizations that occur in patients with malignant stroke, subarachnoid/intracranial hemorrhage, and traumatic brain injury are known to facilitate neuronal damage in metabolically compromised brain tissue. The dramatic failure of brain ion homeostasis caused by propagating spreading depolarizations results in neuronal and astroglial swelling. In essence, swelling is the initial response and a sign of the acute neuronal injury that follows if energy deprivation is maintained. Choosing spreading depolarizations as a target for therapeutic intervention, we have used human brain slices and in vivo real-time two-photon laser scanning microscopy in the mouse neocortex to study potentially useful therapeutics against spreading depolarization-induced injury.We have shown that anoxic or terminal depolarization, a spreading depolarization wave ignited in the ischemic core where neurons cannot repolarize, can be evoked in human slices from pediatric brains during simulated ischemia induced by oxygen/glucose deprivation or by exposure to ouabain. Changes in light transmittance (LT tracked terminal depolarization in time and space. Though spreading depolarizations are notoriously difficult to block, terminal depolarization onset was delayed by dibucaine, a local amide anesthetic and sodium channel blocker. Remarkably, the occurrence of ouabain-induced terminal depolarization was delayed at a concentration of 1 µM that preserves synaptic function. Moreover, in vivo two-photon imaging in the penumbra revealed that, though spreading depolarizations did still occur, spreading depolarization-induced dendritic injury was inhibited by dibucaine administered intravenously at 2.5 mg/kg in a mouse stroke model.Dibucaine mitigated the effects of spreading depolarization at a concentration that could be well-tolerated therapeutically. Hence, dibucaine is a promising candidate to protect the brain from ischemic injury with an approach that does not rely on

Slice-to-Volume Nonrigid Registration of Histological Sections to MR Images of the Human Brain

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Osechinskiy, Sergey; Kruggel, Frithjof

2011-01-01

Registration of histological images to three-dimensional imaging modalities is an important step in quantitative analysis of brain structure, in architectonic mapping of the brain, and in investigation of the pathology of a brain disease. Reconstruction of histology volume from serial sections is a well-established procedure, but it does not address registration of individual slices from sparse sections, which is the aim of the slice-to-volume approach. This study presents a flexible framework for intensity-based slice-to-volume nonrigid registration algorithms with a geometric transformation deformation field parametrized by various classes of spline functions: thin-plate splines (TPS), Gaussian elastic body splines (GEBS), or cubic B-splines. Algorithms are applied to cross-modality registration of histological and magnetic resonance images of the human brain. Registration performance is evaluated across a range of optimization algorithms and intensity-based cost functions. For a particular case of histological data, best results are obtained with a TPS three-dimensional (3D) warp, a new unconstrained optimization algorithm (NEWUOA), and a correlation-coefficient-based cost function. PMID:22567290

Slice-to-Volume Nonrigid Registration of Histological Sections to MR Images of the Human Brain

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Sergey Osechinskiy

2011-01-01

Full Text Available Registration of histological images to three-dimensional imaging modalities is an important step in quantitative analysis of brain structure, in architectonic mapping of the brain, and in investigation of the pathology of a brain disease. Reconstruction of histology volume from serial sections is a well-established procedure, but it does not address registration of individual slices from sparse sections, which is the aim of the slice-to-volume approach. This study presents a flexible framework for intensity-based slice-to-volume nonrigid registration algorithms with a geometric transformation deformation field parametrized by various classes of spline functions: thin-plate splines (TPS, Gaussian elastic body splines (GEBS, or cubic B-splines. Algorithms are applied to cross-modality registration of histological and magnetic resonance images of the human brain. Registration performance is evaluated across a range of optimization algorithms and intensity-based cost functions. For a particular case of histological data, best results are obtained with a TPS three-dimensional (3D warp, a new unconstrained optimization algorithm (NEWUOA, and a correlation-coefficient-based cost function.

Acute hyperammonemia and systemic inflammation is associated with increased extracellular brain adenosine in rats

DEFF Research Database (Denmark)

Bjerring, Peter Nissen; Dale, Nicholas; Larsen, Fin Stolze

2015-01-01

) and cerebral blood flow (CBF). We measured the adenosine concentration with biosensors in rat brain slices exposed to ammonia and in a rat model with hyperammonemia and systemic inflammation. Exposure to ammonia in concentrations from 0.15-10 mM led to increases in the cortical adenosine concentration up to 18......Acute liver failure (ALF) can lead to brain edema, cerebral hyperperfusion and intracranial hypertension. These complications are thought to be mediated by hyperammonemia and inflammation leading to altered brain metabolism. As increased levels of adenosine degradation products have been found...... in brain tissue of patients with ALF we investigated whether hyperammonemia could induce adenosine release in brain tissue. Since adenosine is a potent vasodilator and modulator of cerebral metabolism we furthermore studied the effect of adenosine receptor ligands on intracranial pressure (ICP...

PARP Inhibition Prevents Ethanol-Induced Neuroinflammatory Signaling and Neurodegeneration in Rat Adult-Age Brain Slice Cultures

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Tajuddin, Nuzhath; Kim, Hee-Yong

2018-01-01

Using rat adult-age hippocampal-entorhinal cortical (HEC) slice cultures, we examined the role of poly [ADP-ribose] polymerase (PARP) in binge ethanol’s brain inflammatory and neurodegenerative mechanisms. Activated by DNA strand breaks, PARP (principally PARP1 in the brain) promotes DNA repair via poly [ADP-ribose] (PAR) products, but PARP overactivation triggers regulated neuronal necrosis (e.g., parthanatos). Previously, we found that brain PARP1 levels were upregulated by neurotoxic ethanol binges in adult rats and HEC slices, and PARP inhibitor PJ34 abrogated slice neurodegeneration. Binged HEC slices also exhibited increased Ca+2-dependent phospholipase A2 (PLA2) isoenzymes (cPLA2 IVA and sPLA2 IIA) that mobilize proinflammatory ω6 arachidonic acid (ARA). We now find in 4-day–binged HEC slice cultures (100 mM ethanol) that PARP1 elevations after two overnight binges precede PAR, cPLA2, and sPLA2 enhancements by 1 day and high-mobility group box-1 (HMGB1), an ethanol-responsive alarmin that augments proinflammatory cytokines via toll-like receptor-4 (TLR4), by 2 days. After verifying that PJ34 effectively blocks PARP activity (↑PAR), we demonstrated that, like PJ34, three other PARP inhibitors—olaparib, veliparib, and 4-aminobenzamide—provided neuroprotection from ethanol. Importantly, PJ34 and olaparib also prevented ethanol’s amplification of the PLA2 isoenzymes, and two PLA2 inhibitors were neuroprotective—thus coupling PARP to PLA2, with PLA2 activity promoting neurodegeneration. Also, PJ34 and olaparib blocked ethanol-induced HMGB1 elevations, linking brain PARP induction to TLR4 activation. The results provide evidence in adult brains that induction of PARP1 may mediate dual neuroinflammatory pathways (PLA2→phospholipid→ARA and HMGB1→TLR4→proinflammatory cytokines) that are complicit in binge ethanol-induced neurodegeneration. PMID:29339456

A simple water-immersion condenser for imaging living brain slices on an inverted microscope.

Science.gov (United States)

Prusky, G T

1997-09-05

Due to some physical limitations of conventional condensers, inverted compound microscopes are not optimally suited for imaging living brain slices with transmitted light. Herein is described a simple device that converts an inverted microscope into an effective tool for this application by utilizing an objective as a condenser. The device is mounted on a microscope in place of the condenser, is threaded to accept a water immersion objective, and has a slot for a differential interference contrast (DIC) slider. When combined with infrared video techniques, this device allows an inverted microscope to effectively image living cells within thick brain slices in an open perfusion chamber.

Temporal slice registration and robust diffusion-tensor reconstruction for improved fetal brain structural connectivity analysis.

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Marami, Bahram; Mohseni Salehi, Seyed Sadegh; Afacan, Onur; Scherrer, Benoit; Rollins, Caitlin K; Yang, Edward; Estroff, Judy A; Warfield, Simon K; Gholipour, Ali

2017-08-01

Diffusion weighted magnetic resonance imaging, or DWI, is one of the most promising tools for the analysis of neural microstructure and the structural connectome of the human brain. The application of DWI to map early development of the human connectome in-utero, however, is challenged by intermittent fetal and maternal motion that disrupts the spatial correspondence of data acquired in the relatively long DWI acquisitions. Fetuses move continuously during DWI scans. Reliable and accurate analysis of the fetal brain structural connectome requires careful compensation of motion effects and robust reconstruction to avoid introducing bias based on the degree of fetal motion. In this paper we introduce a novel robust algorithm to reconstruct in-vivo diffusion-tensor MRI (DTI) of the moving fetal brain and show its effect on structural connectivity analysis. The proposed algorithm involves multiple steps of image registration incorporating a dynamic registration-based motion tracking algorithm to restore the spatial correspondence of DWI data at the slice level and reconstruct DTI of the fetal brain in the standard (atlas) coordinate space. A weighted linear least squares approach is adapted to remove the effect of intra-slice motion and reconstruct DTI from motion-corrected data. The proposed algorithm was tested on data obtained from 21 healthy fetuses scanned in-utero at 22-38 weeks gestation. Significantly higher fractional anisotropy values in fiber-rich regions, and the analysis of whole-brain tractography and group structural connectivity, showed the efficacy of the proposed method compared to the analyses based on original data and previously proposed methods. The results of this study show that slice-level motion correction and robust reconstruction is necessary for reliable in-vivo structural connectivity analysis of the fetal brain. Connectivity analysis based on graph theoretic measures show high degree of modularity and clustering, and short average

Implantation of glioblastoma spheroids into organotypic brain slice cultures as a model for investigating effects of irradiation

DEFF Research Database (Denmark)

Petterson, Stine Asferg; Jakobsen, Ida Pind; Jensen, Stine Skov

2016-01-01

, models for studying the effects of radiotherapy in combination with novel strategies are lacking but important since radiotherapy is the most successful non-surgical treatment of brain tumors. The aim of this study was to establish a glioblastoma spheroid-organotypic rat brain slice culture model...... comprising both tumors, tumor-brain interface and brain tissue to provide a proof of concept that this model is useful for studying effects of radiotherapy. Organotypic brain slice cultures cultured for 1-2 days or 11-16 days corresponding to immature brain and mature brain respectively were irradiated...... with doses between 10 and 50 Gy. There was a high uptake of the cell death marker propidium iodide in the immature cultures. In addition, MAP2 expression decreased whereas GFAP expression increased in these cultures suggesting neuronal death and astrogliosis. We therefore proceeded with the mature cultures...

Intersection Based Motion Correction of Multi-Slice MRI for 3D in utero Fetal Brain Image Formation

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Kim, Kio; Habas, Piotr A.; Rousseau, Francois; Glenn, Orit A.; Barkovich, Anthony J.; Studholme, Colin

2012-01-01

In recent years post-processing of fast multi-slice MR imaging to correct fetal motion has provided the first true 3D MR images of the developing human brain in utero. Early approaches have used reconstruction based algorithms, employing a two step iterative process, where slices from the acquired data are re-aligned to an approximate 3D reconstruction of the fetal brain, which is then refined further using the improved slice alignment. This two step slice-to-volume process, although powerful, is computationally expensive in needing a 3D reconstruction, and is limited in its ability to recover sub-voxel alignment. Here, we describe an alternative approach which we term slice intersection motion correction (SIMC), that seeks to directly co-align multiple slice stacks by considering the matching structure along all intersecting slice pairs in all orthogonally planned slices that are acquired in clinical imaging studies. A collective update scheme for all slices is then derived, to simultaneously drive slices into a consistent match along their lines of intersection. We then describe a 3D reconstruction algorithm that, using the final motion corrected slice locations, suppresses through-plane partial volume effects to provide a single high isotropic resolution 3D image. The method is tested on simulated data with known motions and is applied to retrospectively reconstruct 3D images from a range of clinically acquired imaging studies. The quantitative evaluation of the registration accuracy for the simulated data sets demonstrated a significant improvement over previous approaches. An initial application of the technique to studying clinical pathology is included, where the proposed method recovered up to 15 mm of translation and 30 degrees of rotation for individual slices, and produced full 3D reconstructions containing clinically useful additional information not visible in the original 2D slices. PMID:19744911

Characterization of cortical neuronal and glial alterations during culture of organotypic whole brain slices from neonatal and mature mice.

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Staal, Jerome A; Alexander, Samuel R; Liu, Yao; Dickson, Tracey D; Vickers, James C

2011-01-01

Organotypic brain slice culturing techniques are extensively used in a wide range of experimental procedures and are particularly useful in providing mechanistic insights into neurological disorders or injury. The cellular and morphological alterations associated with hippocampal brain slice cultures has been well established, however, the neuronal response of mouse cortical neurons to culture is not well documented. In the current study, we compared the cell viability, as well as phenotypic and protein expression changes in cortical neurons, in whole brain slice cultures from mouse neonates (P4-6), adolescent animals (P25-28) and mature adults (P50+). Cultures were prepared using the membrane interface method. Propidium iodide labeling of nuclei (due to compromised cell membrane) and AlamarBlue™ (cell respiration) analysis demonstrated that neonatal tissue was significantly less vulnerable to long-term culture in comparison to the more mature brain tissues. Cultures from P6 animals showed a significant increase in the expression of synaptic markers and a decrease in growth-associated proteins over the entire culture period. However, morphological analysis of organotypic brain slices cultured from neonatal tissue demonstrated that there were substantial changes to neuronal and glial organization within the neocortex, with a distinct loss of cytoarchitectural stratification and increased GFAP expression (pglial limitans and, after 14 DIV, displayed substantial cellular protrusions from slice edges, including cells that expressed both glial and neuronal markers. In summary, we present a substantial evaluation of the viability and morphological changes that occur in the neocortex of whole brain tissue cultures, from different ages, over an extended period of culture.

Feasibility and resolution limits of opto-magnetic imaging of neural network activity in brain slices using color centers in diamond

DEFF Research Database (Denmark)

Karadas, Mürsel; Wojciechowski, Adam M.; Huck, Alexander

2018-01-01

We suggest a novel approach for wide-field imaging of the neural network dynamics of brain slices that uses highly sensitivity magnetometry based on nitrogen-vacancy (NV) centers in diamond. Invitro recordings in brain slices is a proven method for the characterization of electrical neural activi...... cell. Our results suggest that imaging of slice activity will be possible with the upcoming generation of NV magnetic field sensors, while single-shot imaging of planar cell activity remains challenging....

Effect of acute and repeated restraint stress on glucose oxidation to CO2 in hippocampal and cerebral cortex slices

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Torres I.L.S.

2001-01-01

Full Text Available It has been suggested that glucocorticoids released during stress might impair neuronal function by decreasing glucose uptake by hippocampal neurons. Previous work has demonstrated that glucose uptake is reduced in hippocampal and cerebral cortex slices 24 h after exposure to acute stress, while no effect was observed after repeated stress. Here, we report the effect of acute and repeated restraint stress on glucose oxidation to CO2 in hippocampal and cerebral cortex slices and on plasma glucose and corticosterone levels. Male adult Wistar rats were exposed to restraint 1 h/day for 50 days in the chronic model. In the acute model there was a single exposure. Immediately or 24 h after stress, the animals were sacrificed and the hippocampus and cerebral cortex were dissected, sliced, and incubated with Krebs buffer, pH 7.4, containing 5 mM glucose and 0.2 µCi D-[U-14C] glucose. CO2 production from glucose was estimated. Trunk blood was also collected, and both corticosterone and glucose were measured. The results showed that corticosterone levels after exposure to acute restraint were increased, but the increase was smaller when the animals were submitted to repeated stress. Blood glucose levels increased after both acute and repeated stress. However, glucose utilization, measured as CO2 production in hippocampal and cerebral cortex slices, was the same in stressed and control groups under conditions of both acute and chronic stress. We conclude that, although stress may induce a decrease in glucose uptake, this effect is not sufficient to affect the energy metabolism of these cells.

Towards 1H-MRSI of the human brain at 7T with slice-selective adiabatic refocusing pulses.

NARCIS (Netherlands)

Scheenen, T.W.J.; Heerschap, A.; Klomp, D.W.J.

2008-01-01

OBJECTIVE: To explore the possibilities of proton spectroscopic imaging (1H-MRSI) of the human brain at 7 Tesla with adiabatic refocusing pulses. MATERIALS AND METHODS: A combination of conventional slice selective excitation and two pairs of slice selective adiabatic refocusing pulses (semi-LASER)

Image-guided recording system for spatial and temporal mapping of neuronal activities in brain slice.

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Choi, Geonho; Lee, Jeonghyeon; Kim, Hyeongeun; Jang, Jaemyung; Im, Changkyun; Jeon, Nooli; Jung, Woonggyu

2018-03-01

In this study, we introduce the novel image-guided recording system (IGRS) for efficient interpretation of neuronal activities in the brain slice. IGRS is designed to combine microelectrode array (MEA) and optical coherence tomography at the customized upright microscope. It allows to record multi-site neuronal signals and image of the volumetric brain anatomy in a single body configuration. For convenient interconnection between a brain image and neuronal signals, we developed the automatic mapping protocol that enables us to project acquired neuronal signals on a brain image. To evaluate the performance of IGRS, hippocampal signals of the brain slice were monitored, and corresponding with two-dimensional neuronal maps were successfully reconstructed. Our results indicated that IGRS and mapping protocol can provide the intuitive information regarding long-term and multi-sites neuronal signals. In particular, the temporal and spatial mapping capability of neuronal signals would be a very promising tool to observe and analyze the massive neuronal activity and connectivity in MEA-based electrophysiological studies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Intersection-based registration of slice stacks to form 3D images of the human fetal brain

DEFF Research Database (Denmark)

Kim, Kio; Hansen, Mads Fogtmann; Habas, Piotr

2008-01-01

Clinical fetal MR imaging of the brain commonly makes use of fast 2D acquisitions of multiple sets of approximately orthogonal 2D slices. We and others have previously proposed an iterative slice-to-volume registration process to recover a geometrically consistent 3D image. However......, these approaches depend on a 3D volume reconstruction step during the slice alignment. This is both computationally expensive and makes the convergence of the registration process poorly defined. In this paper our key contribution is a new approach which considers the collective alignment of all slices directly...... of the approach applied to simulated data and clinically acquired fetal images....

Deconstructing brain-derived neurotrophic factor actions in adult brain circuits to bridge an existing informational gap in neuro-cell biology

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Heather Bowling

2016-01-01

Full Text Available Brain-derived neurotrophic factor (BDNF plays an important role in neurodevelopment, synaptic plasticity, learning and memory, and in preventing neurodegeneration. Despite decades of investigations into downstream signaling cascades and changes in cellular processes, the mechanisms of how BDNF reshapes circuits in vivo remain unclear. This informational gap partly arises from the fact that the bulk of studies into the molecular actions of BDNF have been performed in dissociated neuronal cultures, while the majority of studies on synaptic plasticity, learning and memory were performed in acute brain slices or in vivo. A recent study by Bowling-Bhattacharya et al., measured the proteomic changes in acute adult hippocampal slices following treatment and reported changes in proteins of neuronal and non-neuronal origin that may in concert modulate synaptic release and secretion in the slice. In this paper, we place these findings into the context of existing literature and discuss how they impact our understanding of how BDNF can reshape the brain.

Radioisotopic investigations of zinc uptake into brain slices

International Nuclear Information System (INIS)

Howell, G.A.

1983-01-01

The presence of zinc in the vicinity of the hippocampal mossy fibers has been repeatedly demonstrated, and several lines of evidence suggest that the mossy-fiber zinc is concentrated within the terminals of mossy fibers. In search of insight into the metabolism and function of mossy-fiber zinc, the present study investigated the transport of zinc into tissue slices and the response of the zinc transport to depolarization. Kinetic analysis of zinc accumulation by mouse brain slices in vitro revealed the presence of a high affinity uptake component with an apparent Km of 17.7 μM for hippocampus, 16.6 μM< for cortex and 25 μM for striatum and a V/sub max/ of 9.2 ng/mg/hr for the hippocampus, 10.1 ng/mg/hr for cortex and 9.6 ng/mg/hr for striatum. Cytoarchitectonic differences in zinc transport between the different hippocampal subregions were found with those regions containing granule cells or mossy fiber axons accumulating greater amounts of zinc than the CA 1 region. The present finding that mossy-fiber neuropil selectivity accumulates zinc suggests the presence of a zinc-binding substance unique to mossy-fiber tissue

Metabolic Characterization of Acutely Isolated Hippocampal and Cerebral Cortical Slices Using [U-13C]Glucose and [1,2-13C]Acetate as Substrates.

Science.gov (United States)

McNair, Laura F; Kornfelt, Rasmus; Walls, Anne B; Andersen, Jens V; Aldana, Blanca I; Nissen, Jakob D; Schousboe, Arne; Waagepetersen, Helle S

2017-03-01

Brain slice preparations from rats, mice and guinea pigs have served as important tools for studies of neurotransmission and metabolism. While hippocampal slices routinely have been used for electrophysiology studies, metabolic processes have mostly been studied in cerebral cortical slices. Few comparative characterization studies exist for acute hippocampal and cerebral cortical slices, hence, the aim of the current study was to characterize and compare glucose and acetate metabolism in these slice preparations in a newly established incubation design. Cerebral cortical and hippocampal slices prepared from 16 to 18-week-old mice were incubated for 15-90 min with unlabeled glucose in combination with [U- 13 C]glucose or [1,2- 13 C]acetate. Our newly developed incubation apparatus allows accurate control of temperature and is designed to avoid evaporation of the incubation medium. Subsequent to incubation, slices were extracted and extracts analyzed for 13 C-labeling (%) and total amino acid contents (µmol/mg protein) using gas chromatography-mass spectrometry and high performance liquid chromatography, respectively. Release of lactate from the slices was quantified by analysis of the incubation media. Based on the measured 13 C-labeling (%), total amino acid contents and relative activity of metabolic enzymes/pathways, we conclude that the slice preparations in the current incubation apparatus exhibited a high degree of metabolic integrity. Comparison of 13 C-labeling observed with [U- 13 C]glucose in slices from cerebral cortex and hippocampus revealed no significant regional differences regarding glycolytic or total TCA cycle activities. On the contrary, results from the incubations with [1,2- 13 C]acetate suggest a higher capacity of the astrocytic TCA cycle in hippocampus compared to cerebral cortex. Finally, we propose a new approach for assessing compartmentation of metabolite pools between astrocytes and neurons using 13 C-labeling (%) data obtained from

Time efficient whole-brain coverage with MR Fingerprinting using slice-interleaved echo-planar-imaging.

Science.gov (United States)

Rieger, Benedikt; Akçakaya, Mehmet; Pariente, José C; Llufriu, Sara; Martinez-Heras, Eloy; Weingärtner, Sebastian; Schad, Lothar R

2018-04-27

Magnetic resonance fingerprinting (MRF) is a promising method for fast simultaneous quantification of multiple tissue parameters. The objective of this study is to improve the coverage of MRF based on echo-planar imaging (MRF-EPI) by using a slice-interleaved acquisition scheme. For this, the MRF-EPI is modified to acquire several slices in a randomized interleaved manner, increasing the effective repetition time of the spoiled gradient echo readout acquisition in each slice. Per-slice matching of the signal-trace to a precomputed dictionary allows the generation of T 1 and T 2 * maps with integrated B 1 + correction. Subsequent compensation for the coil sensitivity profile and normalization to the cerebrospinal fluid additionally allows for quantitative proton density (PD) mapping. Numerical simulations are performed to optimize the number of interleaved slices. Quantification accuracy is validated in phantom scans and feasibility is demonstrated in-vivo. Numerical simulations suggest the acquisition of four slices as a trade-off between quantification precision and scan-time. Phantom results indicate good agreement with reference measurements (Difference T 1 : -2.4 ± 1.1%, T 2 *: -0.5 ± 2.5%, PD: -0.5 ± 7.2%). In-vivo whole-brain coverage of T 1 , T 2 * and PD with 32 slices was acquired within 3:36 minutes, resulting in parameter maps of high visual quality and comparable performance with single-slice MRF-EPI at 4-fold scan-time reduction.

Metabolic Characterization of Acutely Isolated Hippocampal and Cerebral Cortical Slices Using [U-(13)C]Glucose and [1,2-(13)C]Acetate as Substrates

DEFF Research Database (Denmark)

McNair, Laura F; Kornfelt, Rasmus; Walls, Anne B

2017-01-01

Brain slice preparations from rats, mice and guinea pigs have served as important tools for studies of neurotransmission and metabolism. While hippocampal slices routinely have been used for electrophysiology studies, metabolic processes have mostly been studied in cerebral cortical slices. Few...

A comparison between endogenous acetylcholiner release and (3H) choline outflow from guinea-pig brain slices

International Nuclear Information System (INIS)

Beani, L.; Bianchi, C.; Siniscalchi, A.; Sivilotti, L.; Tanganelli, S.; Veratti, E.

1986-01-01

The measure of tritium-choline efflux from preloaded brain slices is considered a valid method for studying cholinergic functiton. At variance with th say of endogenous acetylcholine this procedure gives andindex of the release process in the absence of esterase inhibition, thus excluding the dampening of the autoreceptor-mediated negative feedback. In order to establish the equivalence of these approaches the tow methods have been compared on electrically=stimulated guinea-pig brain slices, kept under the ame experimental conditions. The results show that only a partial equivalence of the two methods can be recognized. A drawback of the tritium-choline approach is the exhaustion or dilution of tritium stores, so that drug-induced increases of evoked efflux are minimized

Method of euthanasia affects amygdala plasticity in horizontal brain slices from mice.

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Kulisch, C; Eckers, N; Albrecht, D

2011-10-15

An important consideration in any terminal experiment is the method used for euthanizing animals. Although the prime consideration is that the method is humane, some methods can have a dramatic impact on experimental outcomes. The standard inhalant anesthetic for experiments in brain slices is isoflurane, which replaced the flammable ethers used in the pioneer days of surgery. To our knowledge, there are no data available evaluating the effects of the method of euthanasia on plasticity changes in brain slices. Here, we compare the magnitude of long-term potentiation (LTP) and long-term depression (LTD) in the lateral nucleus of the amygdala (LA) after euthanasia following either ether or isoflurane anesthesia, as well as in mice decapitated without anesthesia. We found no differences in input-output curves using different methods of euthanasia. The LTP magnitude did not differ between ether and normal isoflurane anesthesia. After deep isoflurane anesthesia LTP induced by high frequency stimulation of cortical or intranuclear afferents was significantly reduced compared to ether anesthesia. In contrast to ether anesthesia and decapitation without anesthesia, the low frequency stimulation of cortical afferents induced a reliable LA-LTD after deep isoflurane anesthesia. Low frequency stimulation of intranuclear afferents only caused LTD after pretreatment with ether anesthesia. The results demonstrate that the method of euthanasia can influence brain plasticity for hours at least in the interface chamber. Therefore, the method of euthanasia is an important consideration when brain plasticity will be evaluated. Copyright © 2011 Elsevier B.V. All rights reserved.

Rat Brain Biogenic Amine Levels during Acute and Sub- acute ...

African Journals Online (AJOL)

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2011-05-20

May 20, 2011 ... substances in rat brain regions are altered during acute and sub-acute .... Different areas of the brain such as cerebral cortex (CC), cerebellum (CB), .... dopamine metabolism and differential motor behavioral tolerance.

Ionizing radiation action of transport systems of Na+ and K+ of neutronal membranes. Potassium ions reaccumulation with brain slices

International Nuclear Information System (INIS)

Dvoretsky, A.I.; Shainskaya, A.M.; Ananyeva, T.V.; Kulikova, I.A.

1990-01-01

The biological effect of ionizing radiation (IR) on the Na,K pump of the surviving brain cortex slices was investigated. It was shown that IR leads to marked disturbances in the Na,K pump activity and causes essential phasic changes in potassium ion reaccumulation by brain slices in different time after exposure. The possibility of modelling the radiation effect with the help of phospholipase A2 and decylenic acid was shown. The mechanisms of the functional disturbance of Na-K pump of nerve cells after irradiation are under discussion. (author)

Dopaminergic differentiation of human neural stem cells mediated by co-cultured rat striatal brain slices

DEFF Research Database (Denmark)

Anwar, Mohammad Raffaqat; Andreasen, Christian Maaløv; Lippert, Solvej Kølvraa

2008-01-01

differentiation, we co-cultured cells from a human neural forebrain-derived stem cell line (hNS1) with rat striatal brain slices. In brief, coronal slices of neonatal rat striatum were cultured on semiporous membrane inserts placed in six-well trays overlying monolayers of hNS1 cells. After 12 days of co......Properly committed neural stem cells constitute a promising source of cells for transplantation in Parkinson's disease, but a protocol for controlled dopaminergic differentiation is not yet available. To establish a setting for identification of secreted neural compounds promoting dopaminergic...

Adaptation of Microplate-based Respirometry for Hippocampal Slices and Analysis of Respiratory Capacity

Science.gov (United States)

Schuh, Rosemary A.; Clerc, Pascaline; Hwang, Hyehyun; Mehrabian, Zara; Bittman, Kevin; Chen, Hegang; Polster, Brian M.

2011-01-01

Multiple neurodegenerative disorders are associated with altered mitochondrial bioenergetics. Although mitochondrial O2 consumption is frequently measured in isolated mitochondria, isolated synaptic nerve terminals (synaptosomes), or cultured cells, the absence of mature brain circuitry is a remaining limitation. Here we describe the development of a method that adapts the Seahorse Extracellular Flux Analyzer (XF24) for the microplate-based measurement of hippocampal slice O2 consumption. As a first evaluation of the technique, we compared whole slice bioenergetics to previous measurements made with synaptosomes or cultured neurons. We found that mitochondrial respiratory capacity and O2 consumption coupled to ATP synthesis could be estimated in cultured or acute hippocampal slices with preserved neural architecture. Mouse organotypic hippocampal slices oxidizing glucose displayed mitochondrial O2 consumption that was well-coupled, as determined by the sensitivity to the ATP synthase inhibitor oligomycin. However stimulation of respiration by uncoupler was modest (<120% of basal respiration) compared to previous measurements in cells or synaptosomes, although enhanced slightly (to ~150% of basal respiration) by the acute addition of the mitochondrial complex I-linked substrate pyruvate. These findings suggest a high basal utilization of respiratory capacity in slices and a limitation of glucose-derived substrate for maximal respiration. The improved throughput of microplate-based hippocampal respirometry over traditional O2 electrode-based methods is conducive to neuroprotective drug screening. When coupled with cell type-specific pharmacology or genetic manipulations, the ability to efficiently measure O2 consumption from whole slices should advance our understanding of mitochondrial roles in physiology and neuropathology. PMID:21520220

Hypopituitarism after acute brain injury.

Science.gov (United States)

Urban, Randall J

2006-07-01

Acute brain injury has many causes, but the most common is trauma. There are 1.5-2.0 million traumatic brain injuries (TBI) in the United States yearly, with an associated cost exceeding 10 billion dollars. TBI is the most common cause of death and disability in young adults less than 35 years of age. The consequences of TBI can be severe, including disability in motor function, speech, cognition, and psychosocial and emotional skills. Recently, clinical studies have documented the occurrence of pituitary dysfunction after TBI and another cause of acute brain injury, subarachnoid hemorrhage (SAH). These studies have consistently demonstrated a 30-40% occurrence of pituitary dysfunction involving at least one anterior pituitary hormone following a moderate to severe TBI or SAH. Growth hormone (GH) deficiency is the most common pituitary hormone disorder, occurring in approximately 20% of patients when multiple tests of GH deficiency are used. Within 7-21 days of acute brain injury, adrenal insufficiency is the primary concern. Pituitary function can fluctuate over the first year after TBI, but it is well established by 1 year. Studies are ongoing to assess the effects of hormone replacement on motor function and cognition in TBI patients. Any subject with a moderate to severe acute brain injury should be screened for pituitary dysfunction.

High-resolution multi-slice PET

International Nuclear Information System (INIS)

Yasillo, N.J.; Chintu Chen; Ordonez, C.E.; Kapp, O.H.; Sosnowski, J.; Beck, R.N.

1992-01-01

This report evaluates the progress to test the feasibility and to initiate the design of a high resolution multi-slice PET system. The following specific areas were evaluated: detector development and testing; electronics configuration and design; mechanical design; and system simulation. The design and construction of a multiple-slice, high-resolution positron tomograph will provide substantial improvements in the accuracy and reproducibility of measurements of the distribution of activity concentrations in the brain. The range of functional brain research and our understanding of local brain function will be greatly extended when the development of this instrumentation is completed

Application of triple rule-out with 64-slice spiral CT in the diagnosis of acute chest pain

International Nuclear Information System (INIS)

Li Pengyu; Li Kuncheng; Du Xiangyin; Cao Lizhen; Liu Jiabin; Yang Yanhuui; Liang Zhigang; Zhu Xiaolian; Liu Jian

2007-01-01

Objective: To investigate the performance of triple rule-out with 64-slice spiral CT in the combined examination of pulmonary artery, thoracic aorta and coronary artery for patients with acute chest pain. Methods: Seventy patients who presented with acute chest pain were included in the study. All of the patients underwent retrospective ECG-gated 64-slice computed tomography triple rule-out examination to evaluate the pulmonary arteries, thoracic aorta and coronary arteries. Multi-planar reconstruction (MPR), maximum intensity projection (MIP), curved-planar reconstruction (CPR) and volume rendering (VR) were used to display pulmonary arteries, thoracic aorta and coronary arteries. We evaluated the image quality of coronary artery and the enhancement of the pulmonary artery and thoracic aorta to estimate if the examination can fulfill the clinical demand for the differential diagnosis of acute chest pain. Results: The mean scan time was (8.5±1.0) s, and the dose of contrast medium injected was 100 ml. There were 95.7% (67/70) of patients whose CT values detected in the pulmonary artery and thoracic aorta after enhancement Were ≥200 HU. The image quality of 85.8% (720/839) coronary segments was classified as excellent, 8.6% (72/839) as good, and 5.6% (47/839) as poor. There were 20 eases with coronary stenoses ≥50%, 2 cases with pulmonary embolism, and 2 cases with aortic dissection. Conclusion: The triple rule-out examination with 64-slice spiral CT could depict pulmonary artery, thoracic aorta, and coronary artery in 8 s with good image quality. It has great potential in the etiological diagnosis for the patients with acute chest pain. (authors)

Whole brain CT perfusion in acute anterior circulation ischemia: coverage size matters

International Nuclear Information System (INIS)

Emmer, B.J.; Rijkee, M.; Walderveen, M.A.A. van; Niesten, J.M.; Velthuis, B.K.; Wermer, M.J.H.

2014-01-01

Our aim was to compare infarct core volume on whole brain CT perfusion (CTP) with several limited coverage sizes (i.e., 3, 4, 6, and 8 cm), as currently used in routine clinical practice. In total, 40 acute ischemic stroke patients with non-contrast CT (NCCT) and CTP imaging of anterior circulation ischemia were included. Imaging was performed using a 320-multislice CT. Average volumes of infarct core of all simulated partial coverage sizes were calculated. Infarct core volume of each partial brain coverage was compared with infarct core volume of whole brain coverage and expressed using a percentage. To determine the optimal starting position for each simulated CTP coverage, the percentage of infarct coverage was calculated for every possible starting position of the simulated partial coverage in relation to Alberta Stroke Program Early CT Score in Acute Stroke Triage (ASPECTS 1) level. Whole brain CTP coverage further increased the percentage of infarct core volume depicted by 10 % as compared to the 8-cm coverage when the bottom slice was positioned at the ASPECTS 1 level. Optimization of the position of the region of interest (ROI) in 3 cm, 4 cm, and 8 cm improved the percentage of infarct depicted by 4 % for the 8-cm, 7 % for the 4-cm, and 13 % for the 3-cm coverage size. This study shows that whole brain CTP is the optimal coverage for CTP with a substantial improvement in accuracy in quantifying infarct core size. In addition, our results suggest that the optimal position of the ROI in limited coverage depends on the size of the coverage. (orig.)

Whole brain CT perfusion in acute anterior circulation ischemia: coverage size matters

Energy Technology Data Exchange (ETDEWEB)

Emmer, B.J. [Erasmus Medical Centre, Department of Radiology, Postbus 2040, Rotterdam (Netherlands); Rijkee, M.; Walderveen, M.A.A. van [Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands); Niesten, J.M.; Velthuis, B.K. [University Medical Centre Utrecht, Department of Radiology, Utrecht (Netherlands); Wermer, M.J.H. [Leiden University Medical Centre, Department of Neurology, Leiden (Netherlands)

2014-12-15

Our aim was to compare infarct core volume on whole brain CT perfusion (CTP) with several limited coverage sizes (i.e., 3, 4, 6, and 8 cm), as currently used in routine clinical practice. In total, 40 acute ischemic stroke patients with non-contrast CT (NCCT) and CTP imaging of anterior circulation ischemia were included. Imaging was performed using a 320-multislice CT. Average volumes of infarct core of all simulated partial coverage sizes were calculated. Infarct core volume of each partial brain coverage was compared with infarct core volume of whole brain coverage and expressed using a percentage. To determine the optimal starting position for each simulated CTP coverage, the percentage of infarct coverage was calculated for every possible starting position of the simulated partial coverage in relation to Alberta Stroke Program Early CT Score in Acute Stroke Triage (ASPECTS 1) level. Whole brain CTP coverage further increased the percentage of infarct core volume depicted by 10 % as compared to the 8-cm coverage when the bottom slice was positioned at the ASPECTS 1 level. Optimization of the position of the region of interest (ROI) in 3 cm, 4 cm, and 8 cm improved the percentage of infarct depicted by 4 % for the 8-cm, 7 % for the 4-cm, and 13 % for the 3-cm coverage size. This study shows that whole brain CTP is the optimal coverage for CTP with a substantial improvement in accuracy in quantifying infarct core size. In addition, our results suggest that the optimal position of the ROI in limited coverage depends on the size of the coverage. (orig.)

Spindle-like thalamocortical synchronization in a rat brain slice preparation.

Science.gov (United States)

Tancredi, V; Biagini, G; D'Antuono, M; Louvel, J; Pumain, R; Avoli, M

2000-08-01

We obtained rat brain slices (550-650 microm) that contained part of the frontoparietal cortex along with a portion of the thalamic ventrobasal complex (VB) and of the reticular nucleus (RTN). Maintained reciprocal thalamocortical connectivity was demonstrated by VB stimulation, which elicited orthodromic and antidromic responses in the cortex, along with re-entry of thalamocortical firing originating in VB neurons excited by cortical output activity. In addition, orthodromic responses were recorded in VB and RTN following stimuli delivered in the cortex. Spontaneous and stimulus-induced coherent rhythmic oscillations (duration = 0.4-3.5 s; frequency = 9-16 Hz) occurred in cortex, VB, and RTN during application of medium containing low concentrations of the K(+) channel blocker 4-aminopyridine (0.5-1 microM). This activity, which resembled electroencephalograph (EEG) spindles recorded in vivo, disappeared in both cortex and thalamus during application of the excitatory amino acid receptor antagonist kynurenic acid in VB (n = 6). By contrast, cortical application of kynurenic acid (n = 4) abolished spindle-like oscillations at this site, but not those recorded in VB, where their frequency was higher than under control conditions. Our findings demonstrate the preservation of reciprocally interconnected cortical and thalamic neuron networks that generate thalamocortical spindle-like oscillations in an in vitro rat brain slice. As shown in intact animals, these oscillations originate in the thalamus where they are presumably caused by interactions between RTN and VB neurons. We propose that this preparation may help to analyze thalamocortical synchronization and to understand the physiopathogenesis of absence attacks.

Patch-clamp recordings of rat neurons from acute brain slices of the somatosensory cortex during magnetic stimulation.

Science.gov (United States)

Pashut, Tamar; Magidov, Dafna; Ben-Porat, Hana; Wolfus, Shuki; Friedman, Alex; Perel, Eli; Lavidor, Michal; Bar-Gad, Izhar; Yeshurun, Yosef; Korngreen, Alon

2014-01-01

Although transcranial magnetic stimulation (TMS) is a popular tool for both basic research and clinical applications, its actions on nerve cells are only partially understood. We have previously predicted, using compartmental modeling, that magnetic stimulation of central nervous system neurons depolarized the soma followed by initiation of an action potential in the initial segment of the axon. The simulations also predict that neurons with low current threshold are more susceptible to magnetic stimulation. Here we tested these theoretical predictions by combining in vitro patch-clamp recordings from rat brain slices with magnetic stimulation and compartmental modeling. In agreement with the modeling, our recordings demonstrate the dependence of magnetic stimulation-triggered action potentials on the type and state of the neuron and its orientation within the magnetic field. Our results suggest that the observed effects of TMS are deeply rooted in the biophysical properties of single neurons in the central nervous system and provide a framework both for interpreting existing TMS data and developing new simulation-based tools and therapies.

Patch-clamp recordings of rat neurons from acute brain slices of the somatosensory cortex during magnetic stimulation

Directory of Open Access Journals (Sweden)

Tamar ePashut

2014-06-01

Full Text Available Although transcranial magnetic stimulation (TMS is a popular tool for both basic research and clinical applications, its actions on nerve cells are only partially understood. We have previously predicted, using compartmental modeling, that magnetic stimulation of central nervous system neurons depolarized the soma followed by initiation of an action potential in the initial segment of the axon. The simulations also predict that neurons with low current threshold are more susceptible to magnetic stimulation. Here we tested these theoretical predictions by combining in vitro patch-clamp recordings from rat brain slices with magnetic stimulation and compartmental modeling. In agreement with the modeling, our recordings demonstrate the dependence of magnetic stimulation-triggered action potentials on the type and state of the neuron and its orientation within the magnetic field. Our results suggest that the observed effects of TMS are deeply rooted in the biophysical properties of single neurons in the central nervous system and provide a framework both for interpreting existing TMS data and developing new simulation-based tools and therapies.

Impact of 64-slice coronary CT on the management of patients presenting with acute chest pain: results of a prospective two-centre study

Energy Technology Data Exchange (ETDEWEB)

Christiaens, Luc [Departement d' imagerie Cardiovasculaire, Assistance Publique- Hopitaux de Paris, Hopital Lariboisiere, Paris (France); CHU de Poitiers, Departement de Cardiologie, Poitiers (France); Duchat, Florent; Boudiaf, Mourad; Fargeaudou, Yann; Ledref, Olivier; Soyer, Philippe [Departement d' imagerie Cardiovasculaire, Assistance Publique- Hopitaux de Paris, Hopital Lariboisiere, Paris (France); Tasu, Jean-Pierre [CHU de Poitiers, Departement de Radiologie, Poitiers (France); Sirol, Marc [Departement d' imagerie Cardiovasculaire, Assistance Publique- Hopitaux de Paris, Hopital Lariboisiere, Paris (France); INSERM UFR U942, Insuffisance Cardiaque et Biomarqueurs, Universite Paris 7 - Denis Diderot, Hopital Lariboisiere, Paris (France); Universite Paris VII - Denis Diderot, Assistance Publique - Hopitaux de Paris, Service de Radiologie Vasculaire, Hopital Lariboisiere, Paris (France)

2012-05-15

Our two-centre prospective study evaluates the usefulness of 64-slice coronary computed tomography (CCT) to rule out significant coronary artery stenosis in patients admitted in emergency departments (ED) for acute coronary syndromes (ACS) with low-to-intermediate risk score. Patients (175) admitted for acute chest pain (ACP), unmodified electrocardiogram and first troponin measurement within normal ranges were included. A second troponin measurement and a 64-slice CCT within 24 h were performed. Major adverse cardiac events (MACE) were recorded during follow-up (6 months {+-} 2). 64-slice CCT was either normal or showed non-significant coronary stenosis in the majority of patients (78%). 64-slice CCT depicted significant stenosis (>50% diameter) in 22% of patient whereas initial clinical and biological evaluation was reassuring. For negative CCTs, elevated troponin at second measurement did not modify the strategy or treatment of patients. No MACEs were noted during follow up. In 12% of patients CCT identified unsuspected non-coronary abnormalities. Our study confirms 64-slice CCT utility to rule out significant coronary artery stenosis in 8/10 patients admitted in ED with ACP or ACS with low-to-intermediate risk score. Early discharge with a negative 64-slice CCT is associated with very low risk of cardiac events at 6 months. (orig.)

The effect of nucleotides and adenosine on stimulus-evoked glutamate release from rat brain cortical slices

OpenAIRE

Bennett, Gillian C; Boarder, Michael R

2000-01-01

Evidence has previously been presented that P1 receptors for adenosine, and P2 receptors for nucleotides such as ATP, regulate stimulus-evoked release of biogenic amines from nerve terminals in the brain. Here we investigated whether adenosine and nucleotides exert presynaptic control over depolarisation-elicited glutamate release.Slices of rat brain cortex were perfused and stimulated with pulses of 46 mM K+ in the presence of the glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxyl...

Mesenchymal stem cells support neuronal fiber growth in an organotypic brain slice co-culture model.

Science.gov (United States)

Sygnecka, Katja; Heider, Andreas; Scherf, Nico; Alt, Rüdiger; Franke, Heike; Heine, Claudia

2015-04-01

Mesenchymal stem cells (MSCs) have been identified as promising candidates for neuroregenerative cell therapies. However, the impact of different isolation procedures on the functional and regenerative characteristics of MSC populations has not been studied thoroughly. To quantify these differences, we directly compared classically isolated bulk bone marrow-derived MSCs (bulk BM-MSCs) to the subpopulation Sca-1(+)Lin(-)CD45(-)-derived MSCs(-) (SL45-MSCs), isolated by fluorescence-activated cell sorting from bulk BM-cell suspensions. Both populations were analyzed with respect to functional readouts, that are, frequency of fibroblast colony forming units (CFU-f), general morphology, and expression of stem cell markers. The SL45-MSC population is characterized by greater morphological homogeneity, higher CFU-f frequency, and significantly increased nestin expression compared with bulk BM-MSCs. We further quantified the potential of both cell populations to enhance neuronal fiber growth, using an ex vivo model of organotypic brain slice co-cultures of the mesocortical dopaminergic projection system. The MSC populations were cultivated underneath the slice co-cultures without direct contact using a transwell system. After cultivation, the fiber density in the border region between the two brain slices was quantified. While both populations significantly enhanced fiber outgrowth as compared with controls, purified SL45-MSCs stimulated fiber growth to a larger degree. Subsequently, we analyzed the expression of different growth factors in both cell populations. The results show a significantly higher expression of brain-derived neurotrophic factor (BDNF) and basic fibroblast growth factor in the SL45-MSCs population. Altogether, we conclude that MSC preparations enriched for primary MSCs promote neuronal regeneration and axonal regrowth, more effectively than bulk BM-MSCs, an effect that may be mediated by a higher BDNF secretion.

Parkia biglobosa Improves Mitochondrial Functioning and Protects against Neurotoxic Agents in Rat Brain Hippocampal Slices

Directory of Open Access Journals (Sweden)

Kayode Komolafe

2014-01-01

Full Text Available Objective. Methanolic leaf extracts of Parkia biglobosa, PBE, and one of its major polyphenolic constituents, catechin, were investigated for their protective effects against neurotoxicity induced by different agents on rat brain hippocampal slices and isolated mitochondria. Methods. Hippocampal slices were preincubated with PBE (25, 50, 100, or 200 µg/mL or catechin (1, 5, or 10 µg/mL for 30 min followed by further incubation with 300 µM H2O2, 300 µM SNP, or 200 µM PbCl2 for 1 h. Effects of PBE and catechin on SNP- or CaCl2-induced brain mitochondrial ROS formation and mitochondrial membrane potential (ΔΨm were also determined. Results. PBE and catechin decreased basal ROS generation in slices and blunted the prooxidant effects of neurotoxicants on membrane lipid peroxidation and nonprotein thiol contents. PBE rescued hippocampal cellular viability from SNP damage and caused a significant boost in hippocampus Na+, K+-ATPase activity but with no effect on the acetylcholinesterase activity. Both PBE and catechin also mitigated SNP- or CaCl2-dependent mitochondrial ROS generation. Measurement by safranine fluorescence however showed that the mild depolarization of the ΔΨm by PBE was independent of catechin. Conclusion. The results suggest that the neuroprotective effect of PBE is dependent on its constituent antioxidants and mild mitochondrial depolarization propensity.

Brain perfusion in acute and chronic hyperglycemia in rats

International Nuclear Information System (INIS)

Kikano, G.E.; LaManna, J.C.; Harik, S.I.

1989-01-01

Recent studies show that acute and chronic hyperglycemia cause a diffuse decrease in regional cerebral blood flow and that chronic hyperglycemia decreases the brain L-glucose space. Since these changes can be caused by a decreased density of perfused brain capillaries, we used 30 adult male Wistar rats to study the effect of acute and chronic hyperglycemia on (1) the brain intravascular space using radioiodinated albumin, (2) the anatomic density of brain capillaries using alkaline phosphatase histochemistry, and (3) the fraction of brain capillaries that are perfused using the fluorescein isothiocyanate-dextran method. Our results indicate that acute and chronic hyperglycemia do not affect the brain intravascular space nor the anatomic density of brain capillaries. Also, there were no differences in capillary recruitment among normoglycemic, acutely hyperglycemic, and chronically hyperglycemic rats. These results suggest that the shrinkage of the brain L-glucose space in chronic hyperglycemia is more likely due to changes in the blood-brain barrier permeability to L-glucose

Dual activities of the anti-cancer drug candidate PBI-05204 provide neuroprotection in brain slice models for neurodegenerative diseases and stroke.

Science.gov (United States)

Van Kanegan, Michael J; Dunn, Denise E; Kaltenbach, Linda S; Shah, Bijal; He, Dong Ning; McCoy, Daniel D; Yang, Peiying; Peng, Jiangnan; Shen, Li; Du, Lin; Cichewicz, Robert H; Newman, Robert A; Lo, Donald C

2016-05-12

We previously reported neuroprotective activity of the botanical anti-cancer drug candidate PBI-05204, a supercritical CO2 extract of Nerium oleander, in brain slice and in vivo models of ischemic stroke. We showed that one component of this neuroprotective activity is mediated through its principal cardiac glycoside constituent, oleandrin, via induction of the potent neurotrophic factor brain-derived neurotrophic factor (BDNF). However, we also noted that the concentration-relation for PBI-05204 in the brain slice oxygen-glucose deprivation (OGD) model is considerably broader than that for oleandrin as a single agent. We thus surmised that PBI-05204 contains an additional neuroprotective component(s), distinct from oleandrin. We report here that neuroprotective activity is also provided by the triterpenoid constituents of PBI-05204, notably oleanolic acid. We demonstrate that a sub-fraction of PBI-05204 (Fraction 0-4) containing oleanolic and other triterpenoids, but without cardiac glycosides, induces the expression of cellular antioxidant gene transcription programs regulated through antioxidant transcriptional response elements (AREs). Finally, we show that Fraction 0-4 provides broad neuroprotection in organotypic brain slice models for neurodegeneration driven by amyloid precursor protein (APP) and tau implicated in Alzheimer's disease and frontotemporal dementias, respectively, in addition to ischemic injury modeled by OGD.

Coronary ostial involvement in acute aortic dissection: detection with 64-slice cardiac CT.

LENUS (Irish Health Repository)

Ryan, E Ronan

2012-02-01

A 41-year-old man collapsed after lifting weights at a gym. Following admission to the emergency department, a 64-slice cardiac computed tomography (CT) revealed a Stanford Type A aortic dissection arising from a previous coarctation repair. Multiphasic reconstructions demonstrated an unstable, highly mobile aortic dissection flap that extended proximally to involve the right coronary artery ostium. Our case is an example of the application of electrocardiogram-gated cardiac CT in directly visualizing involvement of the coronary ostia in acute aortic dissection, which may influence surgical management.

Effects of endogenous pyrogen and prostaglandin E2 on hypothalamic neurons in rat brain slices.

Science.gov (United States)

Watanabe, T; Morimoto, A; Murakami, N

1987-06-01

We investigated the effects of endogenous pyrogen and prostaglandin E2 (PGE2) on the preoptic and anterior hypothalamic (POAH) neurons using brain slice preparations from the rat. Partially purified endogenous pyrogen did not change the activities of most of the neurons in the POAH region when applied locally through a micropipette attached to the recording electrode in proximity to the neurons. This indicates that partially purified endogenous pyrogen does not act directly on the neuronal activity in the POAH region. The partially purified endogenous pyrogen, applied into a culture chamber containing a brain slice, facilitated the activities in 24% of the total neurons tested, regardless of the thermal specificity of the neurons. Moreover, PGE2 added to the culture chamber facilitated 48% of the warm-responsive, 33% of the cold-responsive, and 29% of the thermally insensitive neurons. The direction of change in neuronal activity induced by partially purified endogenous pyrogen appears to be almost the same as that induced by PGE2 when these substances were applied by perfusion to the same neuron in the culture chamber. These results suggest that partially purified pyrogen applied to the perfusate of the culture chamber stimulates some constituents of brain tissue to synthesize and release prostaglandin, which in turn affects the neuronal activity of the POAH region.

The impact of computed tomography slice thickness on the assessment of stereotactic, 3D conformal and intensity-modulated radiotherapy of brain tumors.

Science.gov (United States)

Caivano, R; Fiorentino, A; Pedicini, P; Califano, G; Fusco, V

2014-05-01

To evaluate radiotherapy treatment planning accuracy by varying computed tomography (CT) slice thickness and tumor size. CT datasets from patients with primary brain disease and metastatic brain disease were selected. Tumor volumes ranging from about 2.5 to 100 cc and CT scan at different slice thicknesses (1, 2, 4, 6 and 10 mm) were used to perform treatment planning (1-, 2-, 4-, 6- and 10-CT, respectively). For any slice thickness, a conformity index (CI) referring to 100, 98, 95 and 90 % isodoses and tumor size was computed. All the CI and volumes obtained were compared to evaluate the impact of CT slice thickness on treatment plans. The smallest volumes reduce significantly if defined on 1-CT with respect to 4- and 6-CT, while the CT slice thickness does not affect target definition for the largest volumes. The mean CI for all the considered isodoses and CT slice thickness shows no statistical differences when 1-CT is compared to 2-CT. Comparing the mean CI of 1- with 4-CT and 1- with 6-CT, statistical differences appear only for the smallest volumes with respect to 100, 98 and 95 % isodoses-the CI for 90 % isodose being not statistically significant for all the considered PTVs. The accuracy of radiotherapy tumor volume definition depends on CT slice thickness. To achieve a better tumor definition and dose coverage, 1- and 2-CT would be suitable for small targets, while 4- and 6-CT are suitable for the other volumes.

Long-term potentiation protects rat hippocampal slices from the effects of acute hypoxia.

Science.gov (United States)

Youssef, F F; Addae, J I; McRae, A; Stone, T W

2001-07-13

compound. We conclude that LTP causes an appreciable protection of hippocampal slices to various models of acute hypoxia. This phenomenon does not appear to involve desensitisation of AMPA receptors or mediation by NO, but may account for the recognised inverse relationship between educational attainment and the development of dementia.

A novel and generalizable organotypic slice platform to evaluate stem cell potential for targeting pediatric brain tumors

Directory of Open Access Journals (Sweden)

Li Shengwen

2008-05-01

Full Text Available Abstract Brain tumors are now the leading cause of cancer-related deaths in children under age 15. Malignant gliomas are, for all practical purposes, incurable and new therapeutic approaches are desperately needed. One emerging strategy is to use the tumor tracking capacity inherent in many stem cell populations to deliver therapeutic agents to the brain cancer cells. Current limitations of the stem cell therapy strategy include that stem cells are treated as a single entity and lack of uniform technology is adopted for selection of clinically relevant sub-populations of stem cells. Specifically, therapeutic success relies on the selection of a clinically competent stem cell population based on their capacity of targeting brain tumors. A novel and generalizable organotypic slice platform to evaluate stem cell potential for targeting pediatric brain tumors is proposed to fill the gap in the current work flow of stem cell-based therapy. The organotypic slice platform has advantages of being mimic in vivo model, easier to manipulate to optimize parameters than in vivo models such as rodents and primates. This model serves as a framework to address the discrepancy between anticipated in vivo results and actual in vivo results, a critical barrier to timely progress in the field of the use of stem cells for the treatment of neurological disorders.

Immature rat brain slices exposed to oxygen-glucose deprivation as an in vitro model of neonatal hypoxic-ischemic encephalopathy.

Science.gov (United States)

Fernández-López, David; Martínez-Orgado, José; Casanova, Ignacio; Bonet, Bartolomé; Leza, Juan Carlos; Lorenzo, Pedro; Moro, Maria Angeles; Lizasoain, Ignacio

2005-06-30

To analyze whether exposure to oxygen-glucose deprivation (OGD) of immature rat brain slices might reproduce the main pathophysiologic events leading to neuronal death in neonatal hypoxic-ischemic encephalopathy (NHIE), 500 microm-thick brain slices were obtained from 7-day-old Wistar rats, and incubated in oxygenated physiological solution. In OGD group, oxygen and glucose were removed from the medium for 10-30 min (n = 25); then, slices were re-incubated in normal medium. In control group the medium composition remained unchanged (CG, n = 30). Medium samples were obtained every 30 min for 3 h. To analyze neuronal damage, slices were stained with Nissl and CA1 area of hippocampus and cortex were observed under microscopy. In addition, neuronal death was quantified as LDH released to the medium determined by spectrophotometry. Additionally, medium glutamate (Glu) levels were determined by HPLC and those of TNFalpha by ELISA, whereas inducible nitric oxide synthase expression was determined by Western blot performed on slices homogenate. Optimal OGD time was established in 20 min. After OGD, a significant decrease in the number of neurones in hippocampus and cortex was observed. LDH release was maximal at 30 min, when it was five-fold greater than in CG. Furthermore, medium Glu concentrations were 200 times greater than CG levels at the end of OGD period. A linear relationship between Glu and LDH release was demonstrated. Finally, 3 h after OGD a significant induction of iNOS as well as an increase in TNFalpha release were observed. In conclusion, OGD appears as a feasible and reproducible in vitro model, leading to a neuronal damage, which is physiopathologically similar to that found in NHIE.

[Brain oedema and acute liver failure].

Science.gov (United States)

Spahr, L

2003-04-01

Brain oedema leading to intracranial hypertension occurs in a significant proportion of patients with acute liver failure in whom it is a leading cause of death. Although precise pathogenic mechanisms associated to this severe complication remain incompletely understood, increasing evidence points to gut-derived neurotoxins including ammonia as key mediators in cerebral osmotic and perfusion disturbances. The management of brain oedema and intracranial hypertension requires a multidisciplinar approach in a center where liver transplantation is available, as this option is the only treatment modality that provides improvement in outcome. This article reviews the most common causes of acute liver failure and the standard of supportive care management, and describes future potential therapeutic aspects of brain oedema and intracranial hypertension.

Diagnostic value of low-field MRI for acute poisoning brain injury

International Nuclear Information System (INIS)

Dang Lianrong; He Qinyi

2012-01-01

Objective: To investigate the value of low-field MIR in diagnosis of acute CO poisoning brain injury. Methods: The brain MIR and clinical data of 110 patients with acute CO poisoning brain injury confirmed by clinical examination were retrospectively analyzed. Results: Long T1 and T2 signal intensity was showed on MRI in cerebral hemispheres and globus pallidus symmetrically. There were three basic types of MIR manifestations, white matter of brain type, globus pallidus type and brain mixed type. Conclusions: MRI could be used for confirming the degree and range of acute CO poisoning brain injury. It has important clinical value in the diagnosis, staging and prognosis of patients with acute CO poisoning brain injury. (authors)

Effects of the pyrethroid insecticide, deltamethrin, on respiratory modulated hypoglossal motoneurons in a brain stem slice from newborn mice

DEFF Research Database (Denmark)

Rekling, J C; Theophilidis, G

1995-01-01

We have studied the action of deltamethrin on respiratory modulated hypoglossal motoneurons in a brain stem slice from newborn mice. Deltamethrin depolarized the hypoglossal motoneurons, increased the background synaptic noise and reduced the frequency and amplitude of current elicited action...

Glucose-stimulated calcium dynamics in islets of Langerhans in acute mouse pancreas tissue slices.

Directory of Open Access Journals (Sweden)

Andraž Stožer

Full Text Available In endocrine cells within islets of Langerhans calcium ions couple cell stimulation to hormone secretion. Since the advent of modern fluorimetry, numerous in vitro studies employing primarily isolated mouse islets have investigated the effects of various secretagogues on cytoplasmic calcium, predominantly in insulin-secreting beta cells. Due to technical limitations, insights of these studies are inherently limited to a rather small subpopulation of outermost cells. The results also seem to depend on various factors, like culture conditions and duration, and are not always easily reconcilable with findings in vivo. The main controversies regard the types of calcium oscillations, presence of calcium waves, and the level of synchronized activity. Here, we set out to combine the in situ acute mouse pancreas tissue slice preparation with noninvasive fluorescent calcium labeling and subsequent confocal laser scanning microscopy to shed new light on the existing controversies utilizing an innovative approach enabling the characterization of responses in many cells from all layers of islets. Our experiments reproducibly showed stable fast calcium oscillations on a sustained plateau rather than slow oscillations as the predominant type of response in acute tissue slices, and that calcium waves are the mechanistic substrate for synchronization of oscillations. We also found indirect evidence that even a large amplitude calcium signal was not sufficient and that metabolic activation was necessary to ensure cell synchronization upon stimulation with glucose. Our novel method helped resolve existing controversies and showed the potential to help answer important physiological questions, making it one of the methods of choice for the foreseeable future.

β-Adrenoceptor activation depresses brain inflammation and is neuroprotective in lipopolysaccharide-induced sensitization to oxygen-glucose deprivation in organotypic hippocampal slices

Directory of Open Access Journals (Sweden)

Cilio Corrado

2010-12-01

Full Text Available Abstract Background Inflammation acting in synergy with brain ischemia aggravates perinatal ischemic brain damage. The sensitizing effect of pro-inflammatory exposure prior to hypoxia is dependent on signaling by TNF-α through TNF receptor (TNFR 1. Adrenoceptor (AR activation is known to modulate the immune response and synaptic transmission. The possible protective effect of α˜ and β˜AR activation against neuronal damage caused by tissue ischemia and inflammation, acting in concert, was evaluated in murine hippocampal organotypic slices treated with lipopolysaccharide (LPS and subsequently subjected to oxygen-glucose deprivation (OGD. Method Hippocampal slices from mice were obtained at P6, and were grown in vitro for 9 days on nitrocellulose membranes. Slices were treated with β1(dobutamine-, β2(terbutaline-, α1(phenylephrine- and α2(clonidine-AR agonists (5 and 50 μM, respectively during LPS (1 μg/mL, 24 h -exposure followed by exposure to OGD (15 min in a hypoxic chamber. Cell death in the slice CA1 region was assessed by propidium iodide staining of dead cells. Results Exposure to LPS + OGD caused extensive cell death from 4 up to 48 h after reoxygenation. Co-incubation with β1-agonist (50 μM during LPS exposure before OGD conferred complete protection from cell death (P -/- and TNFR2-/- slices exposed to LPS followed by OGD. Conclusions Our data demonstrate that activation of both β1- and β2-receptors is neuroprotective and may offer mechanistic insights valuable for development of neuro-protective strategies in neonates.

Stimulation of estradiol biosynthesis by tributyltin in rat hippocampal slices.

Science.gov (United States)

Munetsuna, Eiji; Hattori, Minoru; Yamazaki, Takeshi

2014-01-01

Hippocampal functions are influenced by steroid hormones, such as testosterone and estradiol. It has been demonstrated that hippocampus-derived steroid hormones play important roles in neuronal protection and synapse formation. Our research groups have demonstrated that estradiol is de novo synthesized in the rat hippocampus. However, the mechanism(s) regulating this synthesis remains unclear. It has been reported that tributyltin, an environmental pollutant, binds to the retinoid X receptor (RXR) and modifies estrogen synthesis in human granulosa-like tumor cells. This compound can penetrate the blood brain barrier, and tends to accumulate in the brain. Based on these facts, we hypothesized that tributyltin could influence the hippocampal estradiol synthesis. A concentration of 0.1 μM tributyltin induced an increase in the mRNA content of P450(17α) and P450arom in hippocampal slices, as determined using real-time PCR. The transcript levels of other steroidogenic enzymes and a steroidogenic acute regulatory protein were not affected. The estradiol level in rat hippocampal slices was subsequently determined using a radioimmunoassay. We found that the estradiol synthesis was stimulated by ∼2-fold following a 48-h treatment with 0.1 μM tributyltin, and this was accompanied by transcriptional activation of P450(17α) and P450arom. Tributyltin stimulated de novo hippocampal estradiol synthesis by modifying the transcription of specific steroidogenic enzymes.

Comparison of iterative model, hybrid iterative, and filtered back projection reconstruction techniques in low-dose brain CT: impact of thin-slice imaging

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Nakaura, Takeshi; Iyama, Yuji; Kidoh, Masafumi; Yokoyama, Koichi [Amakusa Medical Center, Diagnostic Radiology, Amakusa, Kumamoto (Japan); Kumamoto University, Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto (Japan); Oda, Seitaro; Yamashita, Yasuyuki [Kumamoto University, Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto (Japan); Tokuyasu, Shinichi [Philips Electronics, Kumamoto (Japan); Harada, Kazunori [Amakusa Medical Center, Department of Surgery, Kumamoto (Japan)

2016-03-15

The purpose of this study was to evaluate the utility of iterative model reconstruction (IMR) in brain CT especially with thin-slice images. This prospective study received institutional review board approval, and prior informed consent to participate was obtained from all patients. We enrolled 34 patients who underwent brain CT and reconstructed axial images with filtered back projection (FBP), hybrid iterative reconstruction (HIR) and IMR with 1 and 5 mm slice thicknesses. The CT number, image noise, contrast, and contrast noise ratio (CNR) between the thalamus and internal capsule, and the rate of increase of image noise in 1 and 5 mm thickness images between the reconstruction methods, were assessed. Two independent radiologists assessed image contrast, image noise, image sharpness, and overall image quality on a 4-point scale. The CNRs in 1 and 5 mm slice thickness were significantly higher with IMR (1.2 ± 0.6 and 2.2 ± 0.8, respectively) than with FBP (0.4 ± 0.3 and 1.0 ± 0.4, respectively) and HIR (0.5 ± 0.3 and 1.2 ± 0.4, respectively) (p < 0.01). The mean rate of increasing noise from 5 to 1 mm thickness images was significantly lower with IMR (1.7 ± 0.3) than with FBP (2.3 ± 0.3) and HIR (2.3 ± 0.4) (p < 0.01). There were no significant differences in qualitative analysis of unfamiliar image texture between the reconstruction techniques. IMR offers significant noise reduction and higher contrast and CNR in brain CT, especially for thin-slice images, when compared to FBP and HIR. (orig.)

Acute traumatic brain-stem hemorrhage produced by sudden caudal displacement of the brain

International Nuclear Information System (INIS)

Mirvis, S.E.; Wolf, A.L.; Thompson, R.K.

1990-01-01

This paper determines in an experimental canine study and a clinical review, whether acute caudal displacement of the brain following blunt trauma produces hemorrhage in the rostral anterior midline of the brain stem by tethering the basilar to the fixed carotid arteries. In four dogs, a balloon catheter was suddenly inflated over the frontal lobe; in two, the carotid-basilar vascular connections were severed prior to balloon inflation. ICP was monitored during and after balloon inflation. Hemorrhage was verified by MR imaging and direct inspection of the fixed brain specimens. Admission CT scans demonstrating acute traumatic brain stem hemorrhage (TBH) in human patients were reviewed to determine the site of TBH, predominant site of impact, and neurologic outcome

Triazolam-induced modulation of muscarinic acetylcholine receptor in living brain slices as revealed by a new positron-based imaging technique

International Nuclear Information System (INIS)

Murata, T.; Matsumura, K.; Onoe, H.; Watanabe, Y.; Sihver, S.; Sihver, W.; Langstroem, B.; Bergstroem, M.; Yonekura, Y.

1997-01-01

The effect of triazolam, a potent benzodiazepine (BZ) agonist, on muscarinic acetylcholinergic receptor (mAChR) binding was investigated in living brain slices by use of a novel positron-based imaging technique. Fresh rat brain slices were incubated with [ 11 C]N-methyl-4-piperidylbenzilate ([ 11 C]NMPB), a mAChR antagonist, in oxygenated Krebs-Ringer solution at 37 degree C. During incubation, time-resolved imaging of [ 11 C]NMPB binding in the slices was constructed on the storage phosphor screens. Addition of triazolam (1 μM) plus muscimol (30 μM), a GABA A receptor agonist, to the incubation mixture decreased the specific binding of [ 11 C]NMPB. Ro15-1788, a BZ receptor antagonist, prevented this effect, indicating that the effect was exerted through the GABA A /BZ receptor complex. These results demonstrated that stimulation of the GABA A /BZ receptor lowers the affinity of the mAChR for its ligand, which may underlie the BZ-induced amnesia, a serious clinical side effect of BZ. No such effect in the P2-fraction instead implies that the integrity of the neuronal cells and/or their environment is prerequisite for the modulation of mAChR by GABA A /BZ stimulation. (author)

Long-term exposure to nicotine markedly reduces kynurenic acid in rat brain - In vitro and ex vivo evidence

International Nuclear Information System (INIS)

Zielinska, Elzbieta; Kuc, Damian; Zgrajka, Wojciech; Turski, Waldemar A.; Dekundy, Andrzej

2009-01-01

Kynurenic acid (KYNA) is a recognized broad-spectrum antagonist of excitatory amino acid receptors with a particularly high affinity for the glycine co-agonist site of the N-methyl-D-aspartate (NMDA) receptor complex. KYNA is also a putative endogenous neuroprotectant. Recent studies show that KYNA strongly blocks α7 subtype of nicotinic acetylcholine receptors (nAChRs). The present studies were aimed at assessing effects of acute and chronic nicotine exposure on KYNA production in rat brain slices in vitro and ex vivo. In brain slices, nicotine significantly increased KYNA formation at 10 mM but not at 1 or 5 mM. Different nAChR antagonists (dihydro-β-erythroidine, methyllycaconitine and mecamylamine) failed to block the influence exerted by nicotine on KYNA synthesis in cortical slices in vitro. Effects of acute (1 mg/kg, i.p.), subchronic (10-day) and chronic (30-day) administration of nicotine in drinking water (100 μg/ml) on KYNA brain content were evaluated ex vivo. Acute treatment with nicotine (1 mg/kg i.p.) did not affect KYNA level in rat brain. The subchronic exposure to nicotine in drinking water significantly increased KYNA by 43%, while chronic exposure to nicotine resulted in a reduction in KYNA by 47%. Co-administration of mecamylamine with nicotine in drinking water for 30 days reversed the effect exerted by nicotine on KYNA concentration in the cerebral cortex. The present results provide evidence for the hypothesis of reciprocal interaction between the nicotinic cholinergic system and the kynurenine pathway in the brain.

N-Acetylaspartate distribution in rat brain striatum during acute brain ischemia

DEFF Research Database (Denmark)

Sager, T.N.; Laursen, H; Fink-Jensen, A

1999-01-01

Brain N-acetylaspartate (NAA) can be quantified by in vivo proton magnetic resonance spectroscopy (1H-MRS) and is used in clinical settings as a marker of neuronal density. It is, however, uncertain whether the change in brain NAA content in acute stroke is reliably measured by 1H-MRS and how NAA......]e increased linearly to 4 mmol/L after 3 hours and this level was maintained for the next 4 h. From the change in in vivo recovery of the interstitial space volume marker [14C]mannitol, the relative amount of NAA distributed in the interstitial space was calculated to be 0.2% of the total brain NAA during...... normal conditions and only 2 to 6% during ischemia. It was concluded that the majority of brain NAA is intracellularly located during ischemia despite large increases of interstitial [NAA]. Thus, MR quantification of NAA during acute ischemia reflects primarily changes in intracellular levels of NAA...

Expression of hypoxia-inducible factor 1 alpha and oligodendrocyte lineage gene-1 in cultured brain slices after oxygen-glucose deprivation☆

OpenAIRE

Cui, Hong; Han, Weijuan; Yang, Lijun; Chang, Yanzhong

2013-01-01

Oligodendrocyte lineage gene-1 expressed in oligodendrocytes may trigger the repair of neuronal myelin impairment, and play a crucial role in myelin repair. Hypoxia-inducible factor 1α, a transcription factor, is of great significance in premature infants with hypoxic-ischemic brain damage. There is little evidence of direct regulatory effects of hypoxia-inducible factor 1α on oligodendrocyte lineage gene-1. In this study, brain slices of Sprague-Dawley rats were cultured and subjected to oxy...

Acute brain herniation from lead toxicity.

Science.gov (United States)

Berkowitz, Sheldon; Tarrago, Rod

2006-12-01

A 4-year-old black boy was admitted to the hospital with vomiting, low-grade fever, and dehydration that were thought to be caused by viral gastroenteritis. He proceeded over the next 12 hours to rapidly deteriorate with brain herniation leading to brain death. The ultimate cause of death was found to be acute lead intoxication from a swallowed foreign body.

Value of multi-slice spiral CT MPVR reconstruction in the diagnosis of acute appendicitis

International Nuclear Information System (INIS)

Wang Kang; Zhao Zehua; Wang Zhi; Wang Weizhong; Xu Songsen; Zhang Miao; Liu Wenjin; Zhang Guozhen; Feng Dianxu

2005-01-01

Objective: To investigate the value of multi-slice spiral CT MPVR reconstruction in the diagnosis of acute appendicitis. Methods: A total of 39 patients with clinically suspected acute appendicitis underwent surgery from February, 2002 to September, 2003. They were prospectively examined before surgery with routine CT scanning and MPVR reconstruction spiral CT. 31 cases of appendicitis were confirmed after appendectomy. CT scans and surgery-pathology reports were evaluated on a five-grade scale from hyperemic-edematous appendix to abscess (normal appendix: 0 grade). Results: The results of spiral CT MPVR reconstruction were compared with the surgical and pathologic findings at appendectomy, yielding an accuracy of 87.2%, sensitivity of 90.3%, specificity of 75%, positive predictive value of 93.3%, and negative predictive value of 66.7%, respectively. Results of routine CT yielded an accuracy of 38.5%, sensitivity of 38.7%, specificity of 37.5%, positive predictive value of 70.6%, and negative predictive value of 13.6%, respectively. MPVR reconstruction signs of 28 patients with acute appendicitis included enlarged appendix ( > 6 mm) (96.4%), appendicoliths (26.7%), caecal apical thickening (36.7%), periappendiceal inflammation (71.4%), and abscess (10.7%). Conclusion: The use of spiral CT MPVR reconstruction in patients with equivocal clinical presentation suspected of having acute appendicitis can lead to a significant improvement in the preoperative diagnosis and maybe a decrease in surgical-pathologic severity of appendiceal disease. (authors)

Reversible acute methotrexate leukoencephalopathy: atypical brain MR imaging features

International Nuclear Information System (INIS)

Ziereisen, France; Damry, Nash; Christophe, Catherine; Dan, Bernard; Azzi, Nadira; Ferster, Alina

2006-01-01

Unusual acute symptomatic and reversible early-delayed leukoencephalopathy has been reported to be induced by methotrexate (MTX). We aimed to identify the occurrence of such atypical MTX neurotoxicity in children and document its MR presentation. We retrospectively reviewed the clinical findings and brain MRI obtained in 90 children treated with MTX for acute lymphoblastic leukaemia or non-B malignant non-Hodgkin lymphoma. All 90 patients had normal brain imaging before treatment. In these patients, brain imaging was performed after treatment completion and/or relapse and/or occurrence of neurological symptoms. Of the 90 patients, 15 (16.7%) showed signs of MTX neurotoxicity on brain MRI, 9 (10%) were asymptomatic, and 6 (6.7%) showed signs of acute leukoencephalopathy. On the routine brain MRI performed at the end of treatment, all asymptomatic patients had classical MR findings of reversible MTX neurotoxicity, such as abnormal high-intensity areas localized in the deep periventricular white matter on T2-weighted images. In contrast, the six symptomatic patients had atypical brain MRI characterized by T2 high-intensity areas in the supratentorial cortex and subcortical white matter (n=6), cerebellar cortex and white matter (n=4), deep periventricular white matter (n=2) and thalamus (n=1). MR normalization occurred later than clinical recovery in these six patients. In addition to mostly asymptomatic classical MTX neurotoxicity, MTX may induce severe but reversible unusual leukoencephalopathy. It is important to recognize this clinicoradiological presentation in the differential diagnosis of acute neurological deterioration in children treated with MTX. (orig.)

Oxygen Mapping within Healthy and Acutely Infarcted Brain Tissue in Humans Using the NMR Relaxation of Lipids: A Proof-Of-Concept Translational Study.

Science.gov (United States)

Colliez, Florence; Safronova, Marta M; Magat, Julie; Joudiou, Nicolas; Peeters, André P; Jordan, Bénédicte F; Gallez, Bernard; Duprez, Thierry

2015-01-01

The clinical applicability of brain oxygenation mapping using the MOBILE (Mapping of Oxygen By Imaging Lipids relaxation Enhancement) magnetic resonance (MR) technique was assessed in the clinical setting of normal brain and of acute cerebral ischemia as a founding proof-of-concept translational study. Changes in the oxygenation level within healthy brain tissue can be detected by analyzing the spin-lattice proton relaxation ('Global T1' combining water and lipid protons) because of the paramagnetic properties of molecular oxygen. It was hypothesized that selective measurement of the relaxation of the lipid protons ('Lipids T1') would result in enhanced sensitivity of pO2 mapping because of higher solubility of oxygen in lipids than in water, and this was demonstrated in pre-clinical models using the MOBILE technique. In the present study, 12 healthy volunteers and eight patients with acute (48-72 hours) brain infarction were examined with the same clinical 3T MR system. Both Lipids R1 (R1 = 1/T1) and Global R1 were significantly different in the infarcted area and the contralateral unaffected brain tissue, with a higher statistical significance for Lipids R1 (median difference: 0.408 s-1; pbrain tissue of stroke patients were not significantly different from the R1 values calculated in the brain tissue of healthy volunteers. The main limitations of the present prototypic version of the MOBILE sequence are the long acquisition time (4 min), hampering robustness of data in uncooperative patients, and a 2 mm slice thickness precluding accurate measurements in small infarcts because of partial volume averaging effects.

Protection of the blood-brain barrier by hypercapnia during acute hypertension

International Nuclear Information System (INIS)

Baumbach, G.L.; Mayhan, W.G.; Heistad, D.D.

1986-01-01

The purpose of this study was to examine effects of hypercapnia on susceptibility of the blood-brain barrier to disruption during acute hypertension. Two methods were used to test the hypothesis that cerebral vasodilation during hypercapnia increases disruption of the blood-brain barrier. First, permeability of the blood-brain barrier was measured in anesthetized cats with 125 I-labeled serum albumin. Severe hypertension markedly increased permeability of the blood-brain barrier during normocapnia, but not during hypercapnia. The protective effect of hypercapnia was not dependent on sympathetic nerves. Second, in anesthetized rats, permeability of the barrier was quantitated by clearance of fluorescent dextran. Disruption of the blood-brain barrier during hypertension was decreased by hypercapnia. Because disruption of the blood-brain barrier occurred primarily in pial venules, the authors also measured pial venular diameter and pressure. Acute hypertension increased pial venular pressure and diameter in normocapnic rats. Hypercapnia alone increased pial venular pressure and pial venular diameter, and acute hypertension during hypercapnia further increased venular pressure. The magnitude of increase in pial venular pressure during acute hypertension was significantly less in hypercapnic than in normocapnic rats. They conclude that hypercapnia protects the blood-brain barrier. Possible mechanisms of this effect include attenuation of the incremental increase in pial venular pressure by hypercapnia or a direct effect on the blood-brain barrier not related to venous pressure

Organotypic slice cultures containing the preBötzinger complex generate respiratory-like rhythms

DEFF Research Database (Denmark)

Phillips, Wiktor S; Herly, Mikkel; Del Negro, Christopher A

2016-01-01

containing the preBötzinger complex (preBötC), the core inspiratory rhythm generator of the ventrolateral brainstem. We measured bilateral synchronous network oscillations, using calcium-sensitive fluorescent dyes, in both ventrolateral (presumably the preBötC) and dorsomedial regions of 7-43 days in vitro......Acute brainstem slice preparations in vitro have advanced understanding of the cellular and synaptic mechanisms of respiratory rhythm generation, but their inherent limitations preclude long-term manipulation and recording experiments. Here, we developed an organotypic slice culture preparation...... of the brainstem displayed up to 193% faster burst frequency (22.4 ± 8.3 bursts/min) and higher signal amplitude (340%) compared to acute slices. We conclude that preBötC-containing slice cultures retain inspiratory-like rhythmic function and therefore may facilitate lines of experimentation that involve extended...

Does brain slices from pentylenetetrazole-kindled mice provide a more predictive screening model for antiepileptic drugs?

DEFF Research Database (Denmark)

Hansen, Suzanne L.; Sterjev, Zoran; Werngreen, Marie

2012-01-01

The cortical wedge is a commonly applied model for in vitro screening of new antiepileptic drugs (AEDs) and has been extensively used in characterization of well-known AEDs. However, the predictive validity of this model as a screening model has been questioned as, e.g., carbamazepine has been...... screening model for AEDs. To this end, we compared the in vitro and in vivo pharmacological profile of several selected AEDs (phenobarbital, phenytoin, tiagabine, fosphenytoin, valproate, and carbamazepine) along with citalopram using the PTZ-kindled model and brain slices from naïve, saline...

Dynamic changes in glucose metabolism of living rat brain slices induced by hypoxia and neurotoxic chemical-loading revealed by positron autoradiography

International Nuclear Information System (INIS)

Omata, N.; Fujibayashi, Y.; Waki, A.; Sadato, N.; Yano, R.; Yoshimoto, M.; Yonekura, Y.; Murata, T.; Yoshida, S.

1999-01-01

Fresh rat brain slices were incubated with 2-deoxy-2-[ 18 F]-fluoro-D-glucose ([ 18 F]FDG) in oxygenated Krebs-Ringer solution at 36 degree C, and serial two-dimensional time-resolved images of [ 18 F]FDG uptake were obtained from these specimens on imaging plates. The fractional rate constant (= k3*) of [ 18 F]FDG proportional to the cerebral glucose metabolic rate (CMRglc) was evaluated by applying the Gjedde-Patlak graphical method to the image data. With hypoxia loading (oxygen deprivation) or glucose metabolism inhibitors acting on oxidative phosphorylation, the k3* value increased dramatically suggesting enhanced glycolysis. After relieving hypoxia ≤10-min, the k3* value returned to the pre-loading level. In contrast, with ≥20-min hypoxia only partial or no recovery was observed, indicating that irreversible neuronal damage had been induced. However, after loading with tetrodotoxin (TTX), the k3* value also decreased but returned to the pre-loading level even after 70-min TTX-loading, reflecting a transient inhibition of neuronal activity. This technique provides a new means of quantifying dynamic changes in the regional CMRglc in living brain slices in response to various interventions such as hypoxia and neurotoxic chemical-loading as well as determining the viability and prognosis of brain tissues. (author)

Endogenous 24S-hydroxycholesterol modulates NMDAR-mediated function in hippocampal slices.

Science.gov (United States)

Sun, Min-Yu; Izumi, Yukitoshi; Benz, Ann; Zorumski, Charles F; Mennerick, Steven

2016-03-01

N-methyl-D-aspartate receptors (NMDARs), a major subtype of glutamate receptors mediating excitatory transmission throughout the central nervous system (CNS), play critical roles in governing brain function and cognition. Because NMDAR dysfunction contributes to the etiology of neurological and psychiatric disorders including stroke and schizophrenia, NMDAR modulators are potential drug candidates. Our group recently demonstrated that the major brain cholesterol metabolite, 24S-hydroxycholesterol (24S-HC), positively modulates NMDARs when exogenously administered. Here, we studied whether endogenous 24S-HC regulates NMDAR activity in hippocampal slices. In CYP46A1(-/-) (knockout; KO) slices where endogenous 24S-HC is greatly reduced, NMDAR tone, measured as NMDAR-to-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) excitatory postsynaptic current (EPSC) ratio, was reduced. This difference translated into more NMDAR-driven spiking in wild-type (WT) slices compared with KO slices. Application of SGE-301, a 24S-HC analog, had comparable potentiating effects on NMDAR EPSCs in both WT and KO slices, suggesting that endogenous 24S-HC does not saturate its NMDAR modulatory site in ex vivo slices. KO slices did not differ from WT slices in either spontaneous neurotransmission or in neuronal intrinsic excitability, and exhibited LTP indistinguishable from WT slices. However, KO slices exhibited higher resistance to persistent NMDAR-dependent depression of synaptic transmission induced by oxygen-glucose deprivation (OGD), an effect restored by SGE-301. Together, our results suggest that loss of positive NMDAR tone does not elicit compensatory changes in excitability or transmission, but it protects transmission against NMDAR-mediated dysfunction. We expect that manipulating this endogenous NMDAR modulator may offer new treatment strategies for neuropsychiatric dysfunction. Copyright © 2016 the American Physiological Society.

Acute subarachnoid hemorrhage: using 64-slice multidetector CT angiography to ''triage'' patients' treatment

Energy Technology Data Exchange (ETDEWEB)

Agid, R.; Lee, S.K.; Willinsky, R.A.; Farb, R.I.; TerBrugge, K.G. [Toronto Western Hospital, Division of Neuroradiology, Department of Medical Imaging, Toronto, Ontario (Canada)

2006-11-15

To evaluate the clinical role of CT angiography (CTA) in patients with acute subarachnoid hemorrhage (SAH) for treatment decision-making. Consecutive patients with acute SAH had CTA using a 64-slice scanner for initial clinical decision-making. Image processing included multiplanar volume reformatted (MPVR) maximum intensity projections (MIP) and 3D volume-rendered reconstructions. CTAs were used for (1) evaluating the cause of SAH, and (2) triaging aneurysm-bearing patients to the more appropriate management, either surgical clipping or endovascular coiling. CTA findings were confirmed by neurosurgical exploration or catheter angiography (digital subtraction angiography, DSA). Successful coiling provided evidence that triaging to endovascular treatment was correct. Included in the study were 73 patients. CTA findings were confirmed by DSA or neurosurgical operation in 65 patients, and of these 65, 47 had aneurysmal SAH, 3 had vasculitis, 1 had arterial dissection and 14 had no underlying arterial abnormality. The cause of SAH was detected with CTA in 62 out of the 65 patients (95.4%, sensitivity 94%, specificity 100%). CTA revealed the aneurysm in 46 of 47 patients (98%, sensitivity 98%, specificity 100%, positive predictive value 100%, negative predictive value 82.3%), 1 of 3 vasculitides and 1 of 1 dissection. Of the 46 patients with aneurysm, 44 (95.7%) were referred for treatment based on CTA. In 2 patients (2 of 46, 4.4%) CTA was not informative enough to choose treatment requiring DSA. Of the 44 patients, 27 (61.4%) were referred to endovascular treatment and successful coiling was achieved in 25 (25 of 27, 92.6%). CTA using a 64-slice scanner is an accurate tool for detecting and characterizing aneurysms in acute SAH. CTA is useful in the decision process whether to coil or clip an aneurysm. (orig.)

[Experimental study of acute brain swelling under acute intracranial hypertension (author's transl)].

Science.gov (United States)

Shigemori, M; Watanabe, M; Kuramoto, S

1976-12-01

There are many problems about the cause, pathophysiology and treatment of acute brain swelling under intracranial hypertension frequently encountered in the neurosurgical clinics. Generally, rapid increase of the cerebral vasoparesis caused by unknown etiology is thought to be the main cause of acute brain swelling under intracranial hypertension. Moreover, disturbance of the cerebral venous circulatory system is discussed recently by many authors. But, research from the point of systemic respiration and hemodynamics is necessary for resolving these problems. This experiment was designed to study the effects of respiration and hemodynamics on the cerebral vasoparesis. Using 22 adult dogs, acute intracranial hypertension was produced by epidural balloon inflation sustained at the level of 300 - 400 mmH2O. Simultaneously with measurement of intracranial pressure at the epidural space, superior sagittal sinus pressure, respirogram, systemic blood pressure (femoral artery), central venous pressure, common carotid blood flow, EKG and bipolar lead EEG were monitored continuously. The experimental group was divided by the respiratory loading into 5 groups as follows: control (6 cases), 10% CO2 hypercapnia (4 cases), 10% O2 hypoxia (4 cases), stenosis of airway (5 cases), 100% O2-controled respiration (3 cases). 1) Cerebral vasoparesis under acute intracranial hypertension took place earlier and showed more rapid progression in groups of stenosis of airway, hypercapnia and hypoxia than control group of spontaneous respiration in room air. No occurrence of cerebral vasoparesis was found out in a group of 100% O2 controlled respiration. It is proved that increased airway resistance or asphyxia, hypercapnia and hypoxia have strictly reference to the occurrence and progression of cerebral vasoparesis and for the prevention of cerebral vasoparesis, correct 100% O2 cont rolled respiration is effective. 2) From the hemodynamic change, the progression of rapid increase of cerebral

Slice sensitivity profiles and pixel noise of multi-slice CT in comparison with single-slice CT

International Nuclear Information System (INIS)

Schorn, C.; Obenauer, S.; Funke, M.; Hermann, K.P.; Kopka, L.; Grabbe, E.

1999-01-01

Purpose: Presentation and evaluation of slice sensitivity profile and pixel noise of multi-slice CT in comparison to single-slice CT. Methods: Slice sensitivity profiles and pixel noise of a multi-slice CT equiped with a 2D matrix detector array and of a single-slice CT were evaluated in phantom studies. Results: For the single-slice CT the width of the slice sensitivity profiles increased with increasing pitch. In spite of a much higher table speed the slice sensitivity profiles of multi-slice CT were narrower and did not increase with higher pitch. Noise in single-slice CT was independent of pitch. For multi-slice CT noise increased with higher pitch and for the higher pitch decreased slightly with higher detector row collimation. Conclusions: Multi-slice CT provides superior z-resolution and higher volume coverage speed. These qualities fulfill one of the prerequisites for improvement of 3D postprocessing. (orig.) [de

The effect of nucleotides and adenosine on stimulus-evoked glutamate release from rat brain cortical slices.

Science.gov (United States)

Bennett, G C; Boarder, M R

2000-10-01

Evidence has previously been presented that P1 receptors for adenosine, and P2 receptors for nucleotides such as ATP, regulate stimulus-evoked release of biogenic amines from nerve terminals in the brain. Here we investigated whether adenosine and nucleotides exert presynaptic control over depolarisation-elicited glutamate release. Slices of rat brain cortex were perfused and stimulated with pulses of 46 mM K(+) in the presence of the glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxylic acid (0.2 mM). High K(+) substantially increased efflux of glutamate from the slices. Basal glutamate release was unchanged by the presence of nucleotides or adenosine at concentrations of 300 microM. Adenosine, ATP, ADP and adenosine 5'-O-(3-thiotriphoshate) at 300 microM attenuated depolarisation-evoked release of glutamate. However UTP, 2-methylthio ATP, 2-methylthio ADP, and alpha,beta-methylene ATP at 300 microM had no effect on stimulated glutamate efflux. Adenosine deaminase blocked the effect of adenosine, but left the response to ATP unchanged. The A(1) antagonist 8-cyclopentyl-1, 3-dipropylxanthine antagonised the inhibitory effect of both adenosine and ATP. Cibacron blue 3GA inhibited stimulus-evoked glutamate release when applied alone. When cibacron blue 3GA was present with ATP, stimulus-evoked glutamate release was almost eliminated. However, this P2 antagonist had no effect on the inhibition by adenosine. These results show that the release of glutamate from depolarised nerve terminals of the rat cerebral cortex is inhibited by adenosine and ATP. ATP appears to act directly and not through conversion to adenosine.

Local establishment of repetitive long-term potentiation-induced synaptic enhancement in cultured hippocampal slices with divided input pathways.

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Oe, Yuki; Tominaga-Yoshino, Keiko; Ogura, Akihiko

2011-09-01

Long-term potentiation (LTP) in the rodent hippocampus is a popular model for synaptic plasticity, which is considered the cellular basis for brain memory. Because most LTP analysis involves acutely prepared brain slices, however, the longevity of single LTP has not been well documented. Using stable hippocampal slice cultures for long-term examination, we previously found that single LTP disappeared within 1 day. In contrast, repeated induction of LTP led to the development of a distinct type of plasticity that lasted for more than 3 weeks and was accompanied by the formation of new synapses. Naming this novel plastic phenomenon repetitive LTP-induced synaptic enhancement (RISE), we proposed it as a model for the cellular processes involved in long-term memory formation. However, because in those experiments LTP was induced pharmacologically in the whole slice, it is not known whether RISE has input-pathway specificity, an essential property for memory. In this study, we divided the input pathway of CA1 pyramidal neurons by a knife cut and induced LTP three times, the third by tetanic stimulation in one of the divided pathways to express RISE specifically. Voltage-sensitive dye imaging and Golgi-staining performed 2 weeks after the three LTP inductions revealed both enhanced synaptic strength and increased dendritic spine density confined to the tetanized region. These results demonstrate that RISE is a feasible cellular model for long-term memory. Copyright © 2011 Wiley-Liss, Inc.

Culturing of PC12 Cells, Neuronal Cells, Astrocytes Cultures and Brain Slices in an Open Microfluidic System

DEFF Research Database (Denmark)

Al Atraktchi, Fatima Al-Zahraa; Bakmand, Tanya; Rømer Sørensen, Ane

The brain is the center of the nervous system, where serious neurodegenerative diseases such as Parkinson’s, Alzheimer’s and Huntington’s are products of functional loss in the neural cells (1). Typical techniques used to investigate these diseases lack precise control of the cellular surroundings......, in addition to isolating the neural tissue from nutrient delivery and to creating unwanted gradients (2). This means that typical techniques used to investigate neurodegenerative diseases cannot mimic in vivo conditions, as closely as desired. We have developed a novel microfluidic system for culturing PC12...... cells, neuronal cells, astrocytes cultures and brain slices. The microfluidic system provides efficient nutrient delivery, waste removal, access to oxygen, fine control over the neurochemical environment and access to modern microscopy. Additionally, the setup consists of an in vitro culturing...

Stimulation of brain glucose uptake by cannabinoid CB2 receptors and its therapeutic potential in Alzheimer's disease.

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Köfalvi, Attila; Lemos, Cristina; Martín-Moreno, Ana M; Pinheiro, Bárbara S; García-García, Luis; Pozo, Miguel A; Valério-Fernandes, Ângela; Beleza, Rui O; Agostinho, Paula; Rodrigues, Ricardo J; Pasquaré, Susana J; Cunha, Rodrigo A; de Ceballos, María L

2016-11-01

Cannabinoid CB2 receptors (CB2Rs) are emerging as important therapeutic targets in brain disorders that typically involve neurometabolic alterations. We here addressed the possible role of CB2Rs in the regulation of glucose uptake in the mouse brain. To that aim, we have undertaken 1) measurement of (3)H-deoxyglucose uptake in cultured cortical astrocytes and neurons and in acute hippocampal slices; 2) real-time visualization of fluorescently labeled deoxyglucose uptake in superfused hippocampal slices; and 3) in vivo PET imaging of cerebral (18)F-fluorodeoxyglucose uptake. We now show that both selective (JWH133 and GP1a) as well as non-selective (WIN55212-2) CB2R agonists, but not the CB1R-selective agonist, ACEA, stimulate glucose uptake, in a manner that is sensitive to the CB2R-selective antagonist, AM630. Glucose uptake is stimulated in astrocytes and neurons in culture, in acute hippocampal slices, in different brain areas of young adult male C57Bl/6j and CD-1 mice, as well as in middle-aged C57Bl/6j mice. Among the endocannabinoid metabolizing enzymes, the selective inhibition of COX-2, rather than that of FAAH, MAGL or α,βDH6/12, also stimulates the uptake of glucose in hippocampal slices of middle-aged mice, an effect that was again prevented by AM630. However, we found the levels of the endocannabinoid, anandamide reduced in the hippocampus of TgAPP-2576 mice (a model of β-amyloidosis), and likely as a consequence, COX-2 inhibition failed to stimulate glucose uptake in these mice. Together, these results reveal a novel general glucoregulatory role for CB2Rs in the brain, raising therapeutic interest in CB2R agonists as nootropic agents. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Estrogen receptor beta and 2-arachydonoylglycerol mediate the suppressive effects of estradiol on frequency of postsynaptic currents in gonadotropin-releasing hormone neurons of metestrous mice: an acute slice electrophysiological study

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Flóra eBálint

2016-03-01

Full Text Available Gonadotropin-releasing hormone (GnRH neurons are controlled by 17β-estradiol (E2 contributing to the steroid feedback regulation of the reproductive axis. In rodents, E2 exerts a negative feedback effect upon GnRH neurons throughout the estrus-diestrus phase of the ovarian cycle. The present study was undertaken to reveal the role of estrogen receptor subtypes in the mediation of the E2 signal and elucidate the downstream molecular machinery of suppression. The effect of E2 administration at low physiological concentration (10 pM on GnRH neurons in acute brain slices obtained from metestrous GnRH-GFP mice was studied under paradigms of blocking or activating estrogen receptor subtypes and interfering with retrograde 2-arachydonoylglycerol (2-AG signaling. Whole-cell patch clamp recordings revealed that E2 significantly diminished the frequency of spontaneous postsynaptic currents (sPSCs in GnRH neurons (49. 62±7.6% which effect was abolished by application of the ERα/β blocker Faslodex (1 µM. Pretreatment of the brain slices with cannabinoid receptor type 1 (CB1 inverse agonist AM251 (1 µM and intracellularly applied endocannabinoid synthesis blocker THL (10 µM significantly attenuated the effect of E2 on the sPSCs. E2 remained effective in the presence of TTX indicating a direct action of E2 on GnRH cells. The ERβ specific agonist DPN (10 pM also significantly decreased the frequency of miniature postsynaptic currents (mPSCs in GnRH neurons. In addition, the suppressive effect of E2 was completely blocked by the selective ERβ antagonist PHTPP (1 µM indicating that ERβ is required for the observed rapid effect of the E2. In contrast, the ERα agonist PPT (10 pM or the membrane-associated G protein-coupled estrogen receptor (GPR30 agonist G1 (10 pM had no significant effect on the frequency of mPSCs in these neurons. AM251 and THL significantly abolished the effect of E2 whereas AM251 eliminated the action of DPN on the mPSCs. These

Differences between the release of radiolabelled and endogenous dopamine from superfused rat brain slices: effects of depolarizing stimuli, amphetamine and synthesis inhibition

International Nuclear Information System (INIS)

Herdon, H.; Strupish, J.; Nahorski, S.R.

1985-01-01

Direct comparisons between radiolabelled and endogenous dopamine (DA) release from superfused rat brain slices have been made. Striatal slices were prelabelled with [ 3 H]dopamine ([ 3 H]DA), then superfused at 0.5 ml/min and the released catecholamines analyzed by HPLC with electrochemical detection and radioactivity present in superfusate fractions also counted. The studies indicate that labelled and endogenous amine release do not always occur in parallel, and that major causes of discrepancy between them may include the presence of a large newly-synthesized component in endogenous release and the uneven distribution of labelled amine within endogenous releasable pools. The results also suggest that the prelabelling process itself may alter the pools contributing to subsequent endogenous release. (Auth.)

Understanding about diagnosis of acute small bowel retrograde intussusception in adults by means of 64-slice-spinal CT

International Nuclear Information System (INIS)

Jiang Ruizhou; Chen Jincheng

2009-01-01

Objective: To have a further study of the value of MSCT in diagnosing acute small bowel retrograde intussusception in adults by means of 64-slice-spinal CT. Methods: A 46-year-old female patient with the history of abdominal operation was found having acute mechanical small bowel obstruction through plain X-ray radiograph. 64-slice MSCT was performed afterwards (plain scan + 3 stage contrast scans). Hence, evidence is provided for operation. Results: Using the technique of MSCT for the patient can promptly approach the diagnosis of jejuno-jejunal intussusception with severe bowel obstruction; no small bowel tumor or other organic lesion found in this case. With the patient who has the history of abdominal operations, MSCT can predict the reason of adhesion causing bowel intussusception, and provide the evidence for operation; whereas MSCT with contrast media offers a further investigation of the blood supply to the bowels through SMA, and observation of blood circulation through the intussuscepting site, which represents venous congestion of intussusception. This case is a retrograde small bowel intussusception and confirmed with operation evidence. A greater amount of gas and fluid is accumulated between the dilated space of middle-distal portion of intussusceptum and intussuscipiens. Nevertheless, less gas at the proximal portion and that can be an important sign for retrograde intussusception. Conclusion: MSCT is a good choice of examination for diagnosis of adult's intussusception. As the literature mentioned the advantages of MSCT for observing the circulation of intussusceptum and whether the diagnosis is antegrade or retrograde intussusception is also essential. (authors)

Clinical feasibility of simultaneous multi-slice imaging with blipped-CAIPI for diffusion-weighted imaging and diffusion-tensor imaging of the brain.

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Yokota, Hajime; Sakai, Koji; Tazoe, Jun; Goto, Mariko; Imai, Hiroshi; Teramukai, Satoshi; Yamada, Kei

2017-12-01

Background Simultaneous multi-slice (SMS) imaging is starting to be used in clinical situation, although evidence of clinical feasibility is scanty. Purpose To prospectively assess the clinical feasibility of SMS diffusion-weighted imaging (DWI) and diffusion-tensor imaging (DTI) with blipped-controlled aliasing in parallel imaging for brain lesions. Material and Methods The institutional review board approved this study. This study included 156 hyperintense lesions on DWI from 32 patients. A slice acceleration factor of 2 was applied for SMS scans, which allowed shortening of the scan time by 41.3%. The signal-to-noise ratio (SNR) was calculated for brain tissue of a selected slice. The contrast-to-noise ratio (CNR), apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were calculated in 36 hyperintense lesions with a diameter of three pixels or more. Visual assessment was performed for all 156 lesions. Tractography of the corticospinal tract of 29 patients was evaluated. The number of tracts and averaged tract length were used for quantitative analysis, and visual assessment was evaluated by grading. Results The SMS scan showed no bias and acceptable 95% limits of agreement compared to conventional scans in SNR, CNR, and ADC on Bland-Altman analyses. Only FA of the lesions was higher in the SMS scan by 9% ( P = 0.016), whereas FA of the surrounding tissues was similar. Quantitative analysis of tractography showed similar values. Visual assessment of DWI hyperintense lesions and tractography also resulted in comparable evaluation. Conclusion SMS imaging was clinically feasible for imaging quality and quantitative values compared with conventional DWI and DTI.

Three-dimensional electrode array for brain slice culture

DEFF Research Database (Denmark)

Vazquez Rodriguez, Patricia

Multielektroder arrays (MEA) er rækker af elektroder mest i mikrometer størrelse, som er blevet brugt i stor omfang til at stimulere og måle elektrisk aktivitet fra neuronale netværker. Brug af disse for at analysere hjerne slices (hjerneskiver) kan give indsigt i interaktioner mellem neuroner, e...

Atorvastatin and Fluoxetine Prevent Oxidative Stress and Mitochondrial Dysfunction Evoked by Glutamate Toxicity in Hippocampal Slices.

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Ludka, Fabiana K; Dal-Cim, Tharine; Binder, Luisa Bandeira; Constantino, Leandra Celso; Massari, Caio; Tasca, Carla I

2017-07-01

Atorvastatin has been shown to exert a neuroprotective action by counteracting glutamatergic toxicity. Recently, we have shown atorvastatin also exerts an antidepressant-like effect that depends on both glutamatergic and serotonergic systems modulation. Excitotoxicity is involved in several brain disorders including depression; thus, it is suggested that antidepressants may target glutamatergic system as a final common pathway. In this study, a comparison of the mechanisms involved in the putative neuroprotective effect of a repetitive atorvastatin or fluoxetine treatment against glutamate toxicity in hippocampal slices was performed. Adult Swiss mice were treated with atorvastatin (10 mg/kg, p.o.) or fluoxetine (10 mg/kg, p.o.), once a day during seven consecutive days. On the eighth day, animals were killed and hippocampal slices were obtained and subjected to an in vitro protocol of glutamate toxicity. An acute treatment of atorvastatin or fluoxetine was not neuroprotective; however, the repeated atorvastatin or fluoxetine treatment prevented the decrease in cellular viability induced by glutamate in hippocampal slices. The loss of cellular viability induced by glutamate was accompanied by increased D-aspartate release, increased reactive oxygen species (ROS) and nitric oxide (NO) production, and impaired mitochondrial membrane potential. Atorvastatin or fluoxetine repeated treatment also presented an antidepressant-like effect in the tail suspension test. Atorvastatin or fluoxetine treatment was effective in protecting mice hippocampal slices from glutamate toxicity by preventing the oxidative stress and mitochondrial dysfunction.

Interleukin-1 and acute brain injury

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Katie N Murray

2015-02-01

Full Text Available Inflammation is the key host-defense response to infection and injury, yet also a major contributor to a diverse range of diseases, both peripheral and central in origin. Brain injury as a result of stroke or trauma is a leading cause of death and disability worldwide, yet there are no effective treatments, resulting in enormous social and economic costs. Increasing evidence, both preclinical and clinical, highlights inflammation as an important factor in stroke, both in determining outcome and as a contributor to risk. A number of inflammatory mediators have been proposed as key targets for intervention to reduce the burden of stroke, several reaching clinical trial, but as yet yielding no success. Many factors could explain these failures, including the lack of robust preclinical evidence and poorly designed clinical trials, in addition to the complex nature of the clinical condition. Lack of consideration in preclinical studies of associated co-morbidities prevalent in the clinical stroke population is now seen as an important omission in previous work. These co-morbidities (atherosclerosis, hypertension, diabetes, infection have a strong inflammatory component, supporting the need for greater understanding of how inflammation contributes to acute brain injury. Interleukin (IL-1 is the prototypical pro-inflammatory cytokine, first identified many years ago as the endogenous pyrogen. Research over the last 20 years or so reveals that IL-1 is an important mediator of neuronal injury and blocking the actions of IL-1 is beneficial in a number of experimental models of brain damage. Mechanisms underlying the actions of IL-1 in brain injury remain unclear, though increasing evidence indicates the cerebrovasculature as a key target. Recent literature supporting this and other aspects of how IL-1 and systemic inflammation in general contribute to acute brain injury are discussed in this review.

CT findings of brain atrophy after chemotherapy in acute leukemia

Energy Technology Data Exchange (ETDEWEB)

Lim, Jun; Park, Seog Hee; Kim, Choon Yul; Bahk, Yong Whee [Catholic University Medicine College, Seoul (Korea, Republic of)

1988-10-15

A study was performed to evaluate the atrophic changes of the central nerve system after chemotherapy in the patients with acute leukemia. The computed tomographic findings and medical records of 20 proven acute leukemia patients under 35 years-old who developed various CNS symptoms and signs during and/or after 2 courses of chemotherapy were reviewed. The results were as follows: 1. Age distribution was from 14 to 5 years (mean was 26 years). Male was 15. 2. Presenting clinical symptoms and signs were headache (16/20), nausea and vomiting (11/20) and loss of consciousness (5/20). 3. Brain atrophy was noted in 16 patients including cortical and subcortical atrophy 15 cases and subcortical atrophy 1 case. 4. Two cases of hemorrhage, one each of intracranial hematoma and chronic subdural hematoma were found in addition to brain atrophy. This showed that chemotherapeutic agents cause brain atrophy in a considerable number of the patients with symptomatic acute leukemia.

Brain hypothermia therapy for childhood acute encephalopathy based on clinical evidence

OpenAIRE

IMATAKA, GEORGE; ARISAKA, OSAMU

2015-01-01

Although previous studies have reported on the effectiveness of brain hypothermia therapy in childhood acute encephalopathy, additional studies in this field are necessary. In this review, we discussed brain hypothermia therapy methods for two clinical conditions for which sufficient evidences are currently available in the literature. The first condition is known as hypoxic-ischemic encephalopathy and occurs in newborns and the second condition is acute encephalopathy which occurs in adults ...

Cranial CT with 64-, 16-, 4- and single-slice CT systems-comparison of image quality and posterior fossa artifacts in routine brain imaging with standard protocols

Energy Technology Data Exchange (ETDEWEB)

Ertl-Wagner, Birgit; Eftimov, Lara; Becker, Christoph; Reiser, Maximilian [University of Munich, Grosshadern (Germany). Institute of Clinical Radiology; Blume, Jeffrey; Cormack, Jean [Brown University, Center for Statistical Sciences, Providence, RI (United States); Bruening, Roland; Brueckmann, Hartmut [University of Munich, Grosshadern (Germany). Department of Neuroradiology

2008-08-15

Posterior fossa artifacts constitute a characteristic limitation of cranial CT. To identify practical benefits and drawbacks of newer CT systems with reduced collimation in routine cranial imaging, we aimed to investigate image quality, posterior fossa artifacts and parenchymal delineation in non-enhanced CT (NECT) with 1-, 4-, 16- and 64-slice scanners using standard scan protocols. We prospectively enrolled 25 consecutive patients undergoing NECT on a 64-slice CT. Three groups with 25 patients having undergone NECT on 1-, 4- and 16-slice CT machines were matched regarding age and sex. Standard routine CT parameters were used on each CT system with helical acquisition in the posterior fossa; the parameters varied regarding collimation and radiation dose. Three blinded readers independently assessed the cases regarding image quality, infra- and supratentorial artifacts and delineation of brain parenchymal structures on a five-point ordinal scale. Reading orders were randomized. A proportional odds model that accounted for the correlated nature of the data was fit using generalized estimating equations. Posterior fossa artifacts were significantly reduced, and the delineation of infratentorial brain structures was significantly improved with the thinner collimation used for the newer CT systems (p<0.001). No significant differences were observed for midbrain structures (p>0.5). The thinner collimation available on modern CT systems leads to reduced posterior fossa artifacts and to a better delineation of brain parenchyma in the posterior fossa. (orig.)

Parallel and patterned optogenetic manipulation of neurons in the brain slice using a DMD-based projector.

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Sakai, Seiichiro; Ueno, Kenichi; Ishizuka, Toru; Yawo, Hiromu

2013-01-01

Optical manipulation technologies greatly advanced the understanding of the neuronal network and its dysfunctions. To achieve patterned and parallel optical switching, we developed a microscopic illumination system using a commercial DMD-based projector and a software program. The spatiotemporal patterning of the system was evaluated using acute slices of the hippocampus. The neural activity was optically manipulated, positively by the combination of channelrhodopsin-2 (ChR2) and blue light, and negatively by the combination of archaerhodopsin-T (ArchT) and green light. It is suggested that our projector-managing optical system (PMOS) would effectively facilitate the optogenetic analyses of neurons and their circuits. Copyright © 2012 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Systems biomarkers as acute diagnostics and chronic monitoring tools for traumatic brain injury

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Wang, Kevin K. W.; Moghieb, Ahmed; Yang, Zhihui; Zhang, Zhiqun

2013-05-01

Traumatic brain injury (TBI) is a significant biomedical problem among military personnel and civilians. There exists an urgent need to develop and refine biological measures of acute brain injury and chronic recovery after brain injury. Such measures "biomarkers" can assist clinicians in helping to define and refine the recovery process and developing treatment paradigms for the acutely injured to reduce secondary injury processes. Recent biomarker studies in the acute phase of TBI have highlighted the importance and feasibilities of identifying clinically useful biomarkers. However, much less is known about the subacute and chronic phases of TBI. We propose here that for a complex biological problem such as TBI, multiple biomarker types might be needed to harness the wide range of pathological and systemic perturbations following injuries, including acute neuronal death, neuroinflammation, neurodegeneration and neuroregeneration to systemic responses. In terms of biomarker types, they range from brain-specific proteins, microRNA, genetic polymorphism, inflammatory cytokines and autoimmune markers and neuro-endocrine hormones. Furthermore, systems biology-driven biomarkers integration can help present a holistic approach to understanding scenarios and complexity pathways involved in brain injury.

The effect of α-, β-adrenergic receptor agonists and antagonists of the efflux of 22Na and uptake of 42K by rat brain cortical slices

International Nuclear Information System (INIS)

Phillis, J.W.; Wu, P.H.; Thierry, D.L.

1982-01-01

The effects of norepinephrine on ion fluxes in rat brain cortical slices have now been ascertained. 22 Na efflux and 42 K influx are enhanced by norepinephrine. The increase in ion fluxes can be blocked by ouabain, phentolamine and propranolol, suggesting that the catecholamine activates a membrane sodium pump by a receptor-mediated step. The facilitation of 22 Na efflux is stereospecific as demonstrated by the very weak action of D-norepinephrine at 10 -5 M concentration. Various α-adrenergic and β-adrenergic receptor agonists, including oxymetazoline, naphazoline, clonidine, tramazoline, methoxamine, phenylephrine, L-isoproterenol and methoxyphenamine are potent stimulants of the sodium pump as demonstrated by their enhancement of ion fluxes in rat brain cortical slices. The results are consistent with the hypothesis that norepinephrine hyperpolarizes central neurons by activating an ouabain-sensitive, receptor-mediated sodium pump. (Auth.)

Acute respiratory distress syndrome assessment after traumatic brain injury

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Shahrooz Kazemi

2016-01-01

Full Text Available Background: Acute respiratory distress syndrome (ARDS is one of the most important complications associated with traumatic brain injury (TBI. ARDS is caused by inflammation of the lungs and hypoxic damage with lung physiology abnormalities associated with acute respiratory distress syndrome. Aim of this study is to determine the epidemiology of ARDS and the prevalence of risk factors. Methods: This prospective study performed on patients with acute traumatic head injury hospitalization in the intensive care unit of the Shohaday-e Haftom-e-Tir Hospital (September 2012 to September 2013 done. About 12 months, the data were evaluated. Information including age, sex, education, employment, drug and alcohol addiction, were collected and analyzed. The inclusion criteria were head traumatic patients and exclusion was the patients with chest trauma. Questionnaire was designed with doctors supervision of neurosurgery. Then the collected data were analysis. Results: In this study, the incidence of ARDS was 23.8% and prevalence of metabolic acidosis was 31.4%. Most injury with metabolic acidosis was Subarachnoid hemorrhage (SAH 48 (60% and Subdural hemorrhage (SDH was Next Level with 39 (48% Correlation between Glasgow Coma Scale (GCS and Respiratory Distress Syndrome (ARDS were significantly decreased (P< 0.0001. The level of consciousness in patients with skull fractures significantly lower than those without fractures (P= 0.009 [(2.3±4.6 vs (4.02±7.07]. Prevalence of metabolic acidosis during hospitalization was 80 patients (31.4%. Conclusion: Acute respiratory distress syndrome is a common complication of traumatic brain injury. Management and treatment is essential to reduce the mortality. In this study it was found the age of patients with ARDS was higher than patients without complications. ARDS risk factor for high blood pressure was higher in men. Most victims were pedestrians. The most common injury associated with ARDS was SDH. Our analysis

Acute and chronic changes in brain activity with deep brain stimulation for refractory depression.

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Conen, Silke; Matthews, Julian C; Patel, Nikunj K; Anton-Rodriguez, José; Talbot, Peter S

2018-04-01

Deep brain stimulation is a potential option for patients with treatment-refractory depression. Deep brain stimulation benefits have been reported when targeting either the subgenual cingulate or ventral anterior capsule/nucleus accumbens. However, not all patients respond and optimum stimulation-site is uncertain. We compared deep brain stimulation of the subgenual cingulate and ventral anterior capsule/nucleus accumbens separately and combined in the same seven treatment-refractory depression patients, and investigated regional cerebral blood flow changes associated with acute and chronic deep brain stimulation. Deep brain stimulation-response was defined as reduction in Montgomery-Asberg Depression Rating Scale score from baseline of ≥50%, and remission as a Montgomery-Asberg Depression Rating Scale score ≤8. Changes in regional cerebral blood flow were assessed using [ 15 O]water positron emission tomography. Remitters had higher relative regional cerebral blood flow in the prefrontal cortex at baseline and all subsequent time-points compared to non-remitters and non-responders, with prefrontal cortex regional cerebral blood flow generally increasing with chronic deep brain stimulation. These effects were consistent regardless of stimulation-site. Overall, no significant regional cerebral blood flow changes were apparent when deep brain stimulation was acutely interrupted. Deep brain stimulation improved treatment-refractory depression severity in the majority of patients, with consistent changes in local and distant brain regions regardless of target stimulation. Remission of depression was reached in patients with higher baseline prefrontal regional cerebral blood flow. Because of the small sample size these results are preliminary and further evaluation is necessary to determine whether prefrontal cortex regional cerebral blood flow could be a predictive biomarker of treatment response.

Effect of MgSO4 on the contents of Ca2+ in brain cell and NO in brain tissue of rats with radiation-induced acute brain injury

International Nuclear Information System (INIS)

Yuan Wenjia; Cui Fengmei; Liu Ping; He Chao; Tu Yu; Wang Lili

2009-01-01

The work is to explore the protection of magnesium sulfate(MgSO 4 ) on radiation-induced acute brain injury. Thirty six mature Sprague-Dawley(SD) rats were randomly divided into 3 groups of control, experimental control and experimental therapy group. The whole brains of SD rats of experimental control and experimental therapy group were irradiated with a dose of 20 Gy using 6 MeV electron beam. MgSO 4 was injected into the abdomen of experimental therapy rats group 1 day before, immediately and continue for 5 days after irradiation respectively. The brain tissues were taken on 3, 10, 17 and 24 d after irradiation. Ca 2+ content in brain cell was measured by laser scanning confocal microscopy, and the NO content in brain tissue was detected by the method of nitric acid reductase. Compared with the blank control group, the contents of Ca 2+ in brain cell and NO in brain tissue of the experimental control group increase (P 4 used in early stage can inhibit the contents of Ca 2+ in brain cell and NO in brain tissue after radiation-induced acute brain injury. It means that MgSO 4 has a protective effect on radiation-induced acute brain injury. (authors)

Pyrethroid insecticides evoke neurotransmitter release from rabbit striatal slices

International Nuclear Information System (INIS)

Eells, J.T.; Dubocovich, M.L.

1988-01-01

The effects of the synthetic pyrethroid insecticide fenvalerate ([R,S]-alpha-cyano-3-phenoxybenzyl[R,S]-2-(4-chlorophenyl)-3- methylbutyrate) on neurotransmitter release in rabbit brain slices were investigated. Fenvalerate evoked a calcium-dependent release of [ 3 H]dopamine and [ 3 H]acetylcholine from rabbit striatal slices that was concentration-dependent and specific for the toxic stereoisomer of the insecticide. The release of [ 3 H]dopamine and [ 3 H]acetylcholine by fenvalerate was modulated by D2 dopamine receptor activation and antagonized completely by the sodium channel blocker, tetrodotoxin. These findings are consistent with an action of fenvalerate on the voltage-dependent sodium channels of the presynaptic membrane resulting in membrane depolarization, and the release of dopamine and acetylcholine by a calcium-dependent exocytotic process. In contrast to results obtained in striatal slices, fenvalerate did not elicit the release of [ 3 H]norepinephrine or [ 3 H]acetylcholine from rabbit hippocampal slices indicative of regional differences in sensitivity to type II pyrethroid actions

A Comparative Study of Pituitary Volume Variations in MRI in Acute Onset of Psychiatric Conditions.

Science.gov (United States)

Soni, Brijesh Kumar; Joish, Upendra Kumar; Sahni, Hirdesh; George, Raju A; Sivasankar, Rajeev; Aggarwal, Rohit

2017-02-01

The growing belief that endocrine abnormalities may underlie many mental conditions has led to increased use of imaging and hormonal assays in patients attending to psychiatric OPDs. People who are in an acute phase of a psychiatric disorder show Hypothalamic Pituitary Adrenal (HPA) axis hyperactivity, but the precise underlying central mechanisms are unclear. To assess the pituitary gland volume variations in patients presenting with new onset acute psychiatric illness in comparison with age and gender matched controls by using MRI. The study included 50 patients, with symptoms of acute psychiatric illness presenting within one month of onset of illness and 50 age and gender matched healthy controls. Both patients and controls were made to undergo MRI of the Brain. A 0.9 mm slices of entire brain were obtained by 3 dimensional T1 weighted sequence. Pituitary gland was traced in all sagittal slices. Anterior pituitary and posterior pituitary bright spot were measured separately in each slice. Volume of the pituitary (in cubic centimetre- cm 3 ) was calculated by summing areas. Significance of variations in pituitary gland volumes was compared between the cases and controls using Analysis of Covariance (ANOVA). There were significantly larger pituitary gland volumes in the cases than the controls, irrespective of psychiatric diagnosis (ANOVA, f=15.56; p=0.0002). Pituitary volumes in cases were 15.36% (0.73 cm 3 ) higher than in controls. There is a strong likelihood of HPA axis overactivity during initial phase of all mental disorders along with increased pituitary gland volumes. Further studies including hormonal assays and correlation with imaging are likely to provide further insight into neuroanatomical and pathological basis of psychiatric disorders.

Sequential variation in brain functional magnetic resonance imaging after peripheral nerve injury: A rat study.

Science.gov (United States)

Onishi, Okihiro; Ikoma, Kazuya; Oda, Ryo; Yamazaki, Tetsuro; Fujiwara, Hiroyoshi; Yamada, Shunji; Tanaka, Masaki; Kubo, Toshikazu

2018-04-23

Although treatment protocols are available, patients experience both acute neuropathic pain and chronic neuropathic pain, hyperalgesia, and allodynia after peripheral nerve injury. The purpose of this study was to identify the brain regions activated after peripheral nerve injury using functional magnetic resonance imaging (fMRI) sequentially and assess the relevance of the imaging results using histological findings. To model peripheral nerve injury in male Sprague-Dawley rats, the right sciatic nerve was crushed using an aneurysm clip, under general anesthesia. We used a 7.04T MRI system. T 2 * weighted image, coronal slice, repetition time, 7 ms; echo time, 3.3 ms; field of view, 30 mm × 30 mm; pixel matrix, 64 × 64 by zero-filling; slice thickness, 2 mm; numbers of slices, 9; numbers of average, 2; and flip angle, 8°. fMR images were acquired during electrical stimulation to the rat's foot sole; after 90 min, c-Fos immunohistochemical staining of the brain was performed in rats with induced peripheral nerve injury for 3, 6, and 9 weeks. Data were pre-processed by realignment in the Statistical Parametric Mapping 8 software. A General Linear Model first level analysis was used to obtain T-values. One week after the injury, significant changes were detected in the cingulate cortex, insular cortex, amygdala, and basal ganglia; at 6 weeks, the brain regions with significant changes in signal density were contracted; at 9 weeks, the amygdala and hippocampus showed activation. Histological findings of the rat brain supported the fMRI findings. We detected sequential activation in the rat brain using fMRI after sciatic nerve injury. Many brain regions were activated during the acute stage of peripheral nerve injury. Conversely, during the chronic stage, activation of the amygdala and hippocampus may be related to chronic-stage hyperalgesia, allodynia, and chronic neuropathic pain. Copyright © 2018 Elsevier B.V. All rights reserved.

Direct Visualization of Neurotransmitters in Rat Brain Slices by Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI - MS)

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Fernandes, Anna Maria A. P.; Vendramini, Pedro H.; Galaverna, Renan; Schwab, Nicolas V.; Alberici, Luciane C.; Augusti, Rodinei; Castilho, Roger F.; Eberlin, Marcos N.

2016-12-01

Mass spectrometry imaging (MSI) of neurotransmitters has so far been mainly performed by matrix-assisted laser desorption/ionization (MALDI) where derivatization reagents, deuterated matrix and/or high resolution, or tandem MS have been applied to circumvent problems with interfering ion peaks from matrix and from isobaric species. We herein describe the application of desorption electrospray ionization mass spectrometry imaging (DESI)-MSI in rat brain coronal and sagittal slices for direct spatial monitoring of neurotransmitters and choline with no need of derivatization reagents and/or deuterated materials. The amino acids γ-aminobutyric (GABA), glutamate, aspartate, serine, as well as acetylcholine, dopamine, and choline were successfully imaged using a commercial DESI source coupled to a hybrid quadrupole-Orbitrap mass spectrometer. The spatial distribution of the analyzed compounds in different brain regions was determined. We conclude that the ambient matrix-free DESI-MSI is suitable for neurotransmitter imaging and could be applied in studies that involve evaluation of imbalances in neurotransmitters levels.

Active uptake of substance P carboxy-terminal heptapeptide (5-11) into rat brain and rabbit spinal cord slices

Energy Technology Data Exchange (ETDEWEB)

Nakata, Y; Kusaka, Y; Yajima, H; Segawa, T

1981-12-01

We previously reported that nerve terminals and glial cells lack an active uptake system capable of terminating transmitter action of substance P (SP). In the present study, we demonstrated the existence of an active uptake system for SP carboxy-terminal heptapeptide, (5-11)SP. When the slices from either rat brain or rabbit spinal cord were incubated with (3H)(5-11)SP, the uptake of (5-11)SP into slices was observed. The uptake system has the properties of an active transport mechanism: it is dependent on temperature and sensitive to hypoosmotic treatment and is inhibited by ouabain and dinitrophenol (DNP). In the brain, (5-11)SP was accumulated by means of a high-affinity and a low-affinity uptake system. The Km and the Vmax values for the high-affinity system were 4.20 x 10(-8) M and 7.59 fmol/10 mg wet weight/min, respectively, whereas these values for the low-affinity system were 1.00 x 10(-6) M and 100 fmol/10 mg wet weight/min, respectively. In the spinal cord, there was only one uptake system, with a Km value of 2.16 x 10(-7) M and Vmax value of 26.2 fmol/10 mg wet weight/min. These results suggest that when SP is released from nerve terminals, it is hydrolysed into (5-11)SP before or after acting as a neurotransmitter, which is in turn accumulated into nerve terminals. Therefore, the uptake system may represent a possible mechanism for the inactivation of SP.

Diffusion-weighted magnetic resonance imaging (MRI) in acute brain stem infarction

International Nuclear Information System (INIS)

Narisawa, Aya; Shamoto, Hiroshi; Shimizu, Hiroaki; Tominaga, Teiji; Yoshimoto, Takashi

2001-01-01

Diffusion-weighted magnetic resonance imaging (DWI) provides one of the earliest demonstrations of ischemic lesions. However some lesions may be missed in the acute stage due to technical limitation of DWI. We therefore conducted the study to clarify the sensitivity of DWI to acute brain stem infarctions. Twenty-eight patients with the final diagnosis of brain stem infarction (midbrain 2, pons 9, medulla oblongata 17) who had been examined by DWI within 24 hours of onset were retrospectively analyzed for how sensitively the initial DWI demonstrated the final ischemic lesion. Only obvious (distinguishable with DWI alone without referring clinical symptoms and other informations) hyperintensity on DWI was regarded to show an ischemic lesion. Sixteen (57.1%) out of 28 patients had brain stem infarctions demonstrated by initial DWI. In the remaining 12 cases, no obvious ischemic lesion was evident on initial DWI. Subsequent MRI studies obtained 127 hours, on average after the onset showed infarction in the medulla oblongate in 11 cases and in the pons in one case. Negative findings of DWI in the acute stage does not exclude possibility of the brain stem infarction, in particularly medulla oblongata infarction. (author)

Oxidative stress and apoptosis after acute respiratory hypoxia and reoxygenation in rat brain

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Debora Coimbra-Costa

2017-08-01

Full Text Available Acute hypoxia increases the formation of reactive oxygen species (ROS in the brain. However, the effect of reoxygenation, unavoidable to achieve full recovery of the hypoxic organ, has not been clearly established. The aim of the present study was to evaluate the effects of exposition to acute severe respiratory hypoxia followed by reoxygenation on the evolution of oxidative stress and apoptosis in the brain. We investigated the effect of in vivo acute severe normobaric hypoxia (rats exposed to 7% O2 for 6 h and reoxygenation in normoxia (21% O2 for 24 h or 48 h on oxidative stress markers, the antioxidant system and apoptosis in the brain. After respiratory hypoxia we found increased levels of HIF-1α expression, lipid peroxidation, protein oxidation and nitric oxide in brain extracts. Antioxidant defence systems such as superoxide dismutase (SOD, reduced glutathione (GSH and glutathione peroxidase (GPx and the reduced/oxidized glutathione (GSH/GSSG ratio were significantly decreased in the brain. After 24 h of reoxygenation, oxidative stress parameters and the anti-oxidant system returned to control values. Regarding the apoptosis parameters, acute hypoxia increased cytochrome c, AIF and caspase 3 activity in the brain. The apoptotic effect is greatest after 24 h of reoxygenation. Immunohistochemistry suggests that CA3 and dentate gyrus in the hippocampus seem more susceptible to hypoxia than the cortex. Severe acute hypoxia increases oxidative damage, which in turn could activate apoptotic mechanisms. Our work is the first to demonstrate that after 24 h of reoxygenation oxidative stress is attenuated, while apoptosis is maintained mainly in the hippocampus, which may, in fact, be the cause of impaired brain function. Keywords: Antioxidants, Apoptosis, Normobaric hypoxia, Oxidative stress, Reoxygenation

Brain tissue stiffness is a sensitive marker for acidosis.

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Holtzmann, Kathrin; Gautier, Hélène O B; Christ, Andreas F; Guck, Jochen; Káradóttir, Ragnhildur Thóra; Franze, Kristian

2016-09-15

Carbon dioxide overdose is frequently used to cull rodents for tissue harvesting. However, this treatment may lead to respiratory acidosis, which potentially could change the properties of the investigated tissue. Mechanical tissue properties often change in pathological conditions and may thus offer a sensitive generic readout for changes in biological tissues with clinical relevance. In this study, we performed force-indentation measurements with an atomic force microscope on acute cerebellar slices from adult rats to test if brain tissue undergoes changes following overexposure to CO2 compared to other methods of euthanasia. The pH significantly decreased in brain tissue of animals exposed to CO2. Concomitant with the drop in pH, cerebellar grey matter significantly stiffened. Tissue stiffening was reproduced by incubation of acute cerebellar slices in acidic medium. Tissue stiffness provides an early, generic indicator for pathophysiological changes in the CNS. Atomic force microscopy offers unprecedented high spatial resolution to detect such changes. Our results indicate that the stiffness particularly of grey matter strongly correlates with changes of the pH in the cerebellum. Furthermore, the method of tissue harvesting and preparation may not only change tissue stiffness but very likely also other physiologically relevant parameters, highlighting the importance of appropriate sample preparation. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Attempt to identify the functional areas of the cerebral cortex on CT slices parallel to the orbito-meatal line

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Tanabe, Hirotaka; Okuda, Junichiro; Nishikawa, Takashi; Nishimura, Tsuyoshi (Osaka Univ. (Japan). Faculty of Medicine); Shiraishi, Junzo

1982-06-01

In order to identify the functional brain areas, such as Broca's area, on computed tomography slices parallel to the orbito-meatal line, the numbers of Brodmann's cortical mapping were shown on a diagram of representative brain sections parallel to the orbito-meatal line. Also, we described a method, using cerebral sulci as anatomical landmarks, for projecting lesions shown by CT scan onto the lateral brain diagram. The procedures were as follows. The distribution of lesions on CT slices was determined by the identification of major cerebral sulci and fissures, such as the Sylvian fissure, the central sulcus, and the superior frontal sulcus. Those lesions were then projected onto the lateral diagram by comparing each CT slice with the horizontal diagrams of brain sections. The method was demonstrated in three cases developing neuropsychological symptoms.

An attempt to identify the functional areas of the cerebral cortex on CT slices parallel to the orbito-meatal line

International Nuclear Information System (INIS)

Tanabe, Hirotaka; Okuda, Junichiro; Nishikawa, Takashi; Nishimura, Tsuyoshi; Shiraishi, Junzo.

1982-01-01

In order to identify the functional brain areas, such as Broca's area, on computed tomography slices parallel to the orbito-meatal line, the numbers of Brodmann's cortical mapping were shown on a diagram of representative brain sections parallel to the orbito-meatal line. Also, we described a method, using cerebral sulci as anatomical landmarks, for projecting lesions shown by CT scan onto the lateral brain diagram. The procedures were as follows. The distribution of lesions on CT slices was determined by the identification of major cerebral sulci and fissures, such as the Sylvian fissure, the central sulcus, and the superior frontal sulcus. Those lesions were then projected onto the lateral diagram by comparing each CT slice with the horizontal diagrams of brain sections. The method was demonstrated in three cases developing neuropsychological symptoms. (author)

Comparison of bNOS and chat immunohistochemistry in the laterodorsal tegmentum (LDT) and the pedunculopontine tegmentum (PPT) of the mouse from brain slices prepared for electrophysiology

DEFF Research Database (Denmark)

Veleanu, Maxime; Axen, Tina E; Kristensen, Morten P

2016-01-01

maintains that antibody staining for enzymes involved in synthesis or transport, of acetylcholine would be a more definitive marker and hence, preferable. NEW METHOD: Colocalization of bNOS and CHAT in the LDT/PPT, and presence of parvalbumin (PV), was examined in non-ideally prepared mouse brain slices...

Methods to induce primary and secondary traumatic damage in organotypic hippocampal slice cultures.

Science.gov (United States)

Adamchik, Y; Frantseva, M V; Weisspapir, M; Carlen, P L; Perez Velazquez, J L

2000-04-01

Organotypic brain slice cultures have been used in a variety of studies on neurodegenerative processes [K.M. Abdel-Hamid, M. Tymianski, Mechanisms and effects of intracellular calcium buffering on neuronal survival in organotypic hippocampal cultures exposed to anoxia/aglycemia or to excitotoxins, J. Neurosci. 17, 1997, pp. 3538-3553; D.W. Newell, A. Barth, V. Papermaster, A.T. Malouf, Glutamate and non-glutamate receptor mediated toxicity caused by oxygen and glucose deprivation in organotypic hippocampal cultures, J. Neurosci. 15, 1995, pp. 7702-7711; J.L. Perez Velazquez, M.V. Frantseva, P.L. Carlen, In vitro ischemia promotes glutamate mediated free radical generation and intracellular calcium accumulation in pyramidal neurons of cultured hippocampal slices, J. Neurosci. 23, 1997, pp. 9085-9094; L. Stoppini, L.A. Buchs, D. Muller, A simple method for organotypic cultures of nervous tissue, J. Neurosci. Methods 37, 1991, pp. 173-182; R.C. Tasker, J.T. Coyle, J.J. Vornov, The regional vulnerability to hypoglycemia induced neurotoxicity in organotypic hippocampal culture: protection by early tetrodotoxin or delayed MK 801, J. Neurosci. 12, 1992, pp. 4298-4308.]. We describe two methods to induce traumatic cell damage in hippocampal organotypic cultures. Primary trauma injury was achieved by rolling a stainless steel cylinder (0.9 g) on the organotypic slices. Secondary injury was followed after dropping a weight (0.137 g) on a localised area of the organotypic slice, from a height of 2 mm. The time course and extent of cell death were determined by measuring the fluorescence of the viability indicator propidium iodide (PI) at several time points after the injury. The initial localised impact damage spread 24 and 67 h after injury, cell death being 25% and 54%, respectively, when slices were kept at 37 degrees C. To validate these methods as models to assess neuroprotective strategies, similar insults were applied to slices at relatively low temperatures (30

Effects of the Acute and Chronic Ethanol Intoxication on Acetate Metabolism and Kinetics in the Rat Brain.

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Hsieh, Ya-Ju; Wu, Liang-Chih; Ke, Chien-Chih; Chang, Chi-Wei; Kuo, Jung-Wen; Huang, Wen-Sheng; Chen, Fu-Du; Yang, Bang-Hung; Tai, Hsiao-Ting; Chen, Sharon Chia-Ju; Liu, Ren-Shyan

2018-02-01

Ethanol (EtOH) intoxication inhibits glucose transport and decreases overall brain glucose metabolism; however, humans with long-term EtOH consumption were found to have a significant increase in [1- 11 C]-acetate uptake in the brain. The relationship between the cause and effect of [1- 11 C]-acetate kinetics and acute/chronic EtOH intoxication, however, is still unclear. [1- 11 C]-acetate positron emission tomography (PET) with dynamic measurement of K 1 and k 2 rate constants was used to investigate the changes in acetate metabolism in different brain regions of rats with acute or chronic EtOH intoxication. PET imaging demonstrated decreased [1- 11 C]-acetate uptake in rat brain with acute EtOH intoxication, but this increased with chronic EtOH intoxication. Tracer uptake rate constant K 1 and clearance rate constant k 2 were decreased in acutely intoxicated rats. No significant change was noted in K 1 and k 2 in chronic EtOH intoxication, although 6 of 7 brain regions showed slightly higher k 2 than baseline. These results indicate that acute EtOH intoxication accelerated acetate transport and metabolism in the rat brain, whereas chronic EtOH intoxication status showed no significant effect. In vivo PET study confirmed the modulatory role of EtOH, administered acutely or chronically, in [1- 11 C]-acetate kinetics and metabolism in the rat brain. Acute EtOH intoxication may inhibit the transport and metabolism of acetate in the brain, whereas chronic EtOH exposure may lead to the adaptation of the rat brain to EtOH in acetate utilization. [1- 11 C]-acetate PET imaging is a feasible approach to study the effect of EtOH on acetate metabolism in rat brain. Copyright © 2017 by the Research Society on Alcoholism.

Altered spontaneous brain activity in patients with acute spinal cord injury revealed by resting-state functional MRI.

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Ling Zhu

Full Text Available Previous neuroimaging studies have provided evidence of structural and functional reorganization of brain in patients with chronic spinal cord injury (SCI. However, it remains unknown whether the spontaneous brain activity changes in acute SCI. In this study, we investigated intrinsic brain activity in acute SCI patients using a regional homogeneity (ReHo analysis based on resting-state functional magnetic resonance imaging.A total of 15 patients with acute SCI and 16 healthy controls participated in the study. The ReHo value was used to evaluate spontaneous brain activity, and voxel-wise comparisons of ReHo were performed to identify brain regions with altered spontaneous brain activity between groups. We also assessed the associations between ReHo and the clinical scores in brain regions showing changed spontaneous brain activity.Compared with the controls, the acute SCI patients showed decreased ReHo in the bilateral primary motor cortex/primary somatosensory cortex, bilateral supplementary motor area/dorsal lateral prefrontal cortex, right inferior frontal gyrus, bilateral dorsal anterior cingulate cortex and bilateral caudate; and increased ReHo in bilateral precuneus, the left inferior parietal lobe, the left brainstem/hippocampus, the left cingulate motor area, bilateral insula, bilateral thalamus and bilateral cerebellum. The average ReHo values of the left thalamus and right insula were negatively correlated with the international standards for the neurological classification of spinal cord injury motor scores.Our findings indicate that acute distant neuronal damage has an immediate impact on spontaneous brain activity. In acute SCI patients, the ReHo was prominently altered in brain regions involved in motor execution and cognitive control, default mode network, and which are associated with sensorimotor compensatory reorganization. Abnormal ReHo values in the left thalamus and right insula could serve as potential biomarkers for

Biocompatibility of silicon-based arrays of electrodes coupled to organotypic hippocampal brain slice cultures

DEFF Research Database (Denmark)

Kristensen, Bjarne Winther; Noraberg, J; Thiébaud, P

2001-01-01

by Nissl staining, Timm sulphide silver-staining, microtubule-associated protein 2 (MAP2) and glial fibrillary acidic protein (GFAP) immunostaining, the slice cultures grown on chips did not differ from conventionally grown slice cultures. Neither were there any signs of astrogliosis or neurodegeneration...

Brain MRI findings in acute hepatic encephalopathy in liver transplant recipients.

Science.gov (United States)

Guo, Ruo-Mi; Li, Qing-Ling; Zhong, Li-Ru; Guo, Yu; Jiao, Ju; Chen, Shao-Qiong; Wang, Jin; Zhang, Yong

2018-06-01

Acute hepatic encephalopathy has significant morbidity and mortality in liver transplant recipients unless it is promptly treated. We evaluated the brain magnetic resonance (MR) imaging findings associated with acute hepatic encephalopathy in transplant recipients. We retrospectively reviewed the clinical and imaging data and outcomes of twenty-five liver transplant patients (16 male; mean age, 49.3 years) with clinically diagnosed acute hepatic encephalopathy and forty liver transplant patients (20 males; mean age, 45.5 years) without neurological symptoms suggestive of hepatic encephalopathy at our institution. Bilateral symmetric hyperintensities of the insular cortex and cingulate gyrus were observed in twenty-one patients (84.00%), bilateral symmetric extensive increased cortical signal intensity (involving two or more regions) was observed in 72.00% of the patients, leptomeningeal enhancement in 73.68%, and visualization of prominent venules in 52.00%. The most common symptom at diagnosis was rigidity (n = 14), and the plasma ammonia levels ranged from 68.63 to 192.16 μmol/L. After active treatment, 17 patients gradually recovered, four patients suffered from mild or moderate neurologic deficits, and four patients with widespread brain edema died. The specific brain MR imaging features were bilateral symmetric increased cortical signal intensity, especially in the insular cortex and cingulate gyrus, leptomeningeal enhancement, visualization of the prominent venules, and widespread brain edema. These features may indicate poor prognosis and should alert radiologists to the possibility of acute hepatic encephalopathy in liver transplant recipients and encourage clinicians to prepare appropriate treatment in advance.

Perfusion CT in acute stroke

International Nuclear Information System (INIS)

Eckert, Bernd; Roether, Joachim; Fiehler, Jens; Thomalla, Goetz

2015-01-01

Modern multislice CT scanners enable multimodal protocols including non-enhanced CT, CT angiography, and CT perfusion. A 64-slice CT scanner provides 4-cm coverage. To cover the whole brain, a 128 - 256-slice scanner is needed. The use of perfusion CT requires an optimized scan protocol in order to reduce exposure to radiation. As compared to non-enhanced CT and CT angiography, the use of CT perfusion increases detection rates of cerebral ischemia, especially small cortical ischemic lesions, while the detection of lacunar and infratentorial stroke lesions remains limited. Perfusion CT enables estimation of collateral flow in acute occlusion of large intra- or extracranial arteries. Currently, no established reliable thresholds are available for determining infarct core and penumbral tissue by CT perfusion. Moreover, perfusion parameters depend on the processing algorithms and the software used for calculation. However, a number of studies point towards a reduction of cerebral blood volume (CBV) below 2 ml/100 g as a critical threshold that identifies infarct core. Large CBV lesions are associated with poor outcome even in the context of recanalization. The extent of early ischemic signs on non-enhanced CT remains the main parameter from CT imaging to guide acute reperfusion treatment. Nevertheless, perfusion CT increases diagnostic and therapeutic certainty in the acute setting. Similar to stroke MRI, perfusion CT enables the identification of tissue at risk of infarction by the mismatch between infarct core and the larger area of critical hypoperfusion. Further insights into the validity of perfusion parameters are expected from ongoing trials of mechanical thrombectomy in stroke.

Brain expression of the water channels Aquaporin-1 and -4 in mice with acute liver injury, hyperammonemia and brain edema

DEFF Research Database (Denmark)

Eefsen, Martin; Jelnes, Peter; Schmidt, Lars E

2010-01-01

Cerebral edema is a feared complication to acute liver failure (ALF), but the pathogenesis is still poorly understood. The water channels Aquaporin-1 (Aqp1) and -4 (Aqp4) has been associated with brain edema formation in several neuropathological conditions, indicating a possible role of Aqp1 and....../or Aqp4 in ALF mediated brain edema. We induced acute liver injury and hyperammonemia in mice, to evaluate brain edema formation and the parallel expression of Aqp1 and Aqp4 in ALF. Liver injury and hyperammonemia were induced by +D-galactosamine (GLN) plus lipopolysaccharide (LPS) intraperitoneally......(6266) (p edema in mice with ALF....

Amplitude of Low-Frequency Fluctuations in Multiple-Frequency Bands in Acute Mild Traumatic Brain Injury.

Science.gov (United States)

Zhan, Jie; Gao, Lei; Zhou, Fuqing; Bai, Lijun; Kuang, Hongmei; He, Laichang; Zeng, Xianjun; Gong, Honghan

2016-01-01

Functional disconnectivity during the resting state has been observed in mild traumatic brain injury (mTBI) patients during the acute stage. However, it remains largely unknown whether the abnormalities are related to specific frequency bands of the low-frequency oscillations (LFO). Here, we used the amplitude of low-frequency fluctuations (ALFF) to examine the amplitudes of LFO in different frequency bands (slow-5: 0.01-0.027 Hz; slow-4: 0.027-0.073 Hz; and typical: 0.01-0.08 Hz) in patients with acute mTBI. A total of 24 acute mTBI patients and 24 age-, sex-, and education-matched healthy controls participated in this study. In the typical band, acute mTBI patients showed lower standardized ALFF in the right middle frontal gyrus and higher standardized ALFF in the right lingual/fusiform gyrus and left middle occipital gyrus. Further analyses showed that the difference between groups was concentrated in a narrower (slow-4) frequency band. In the slow-5 band, mTBI patients only exhibited higher standardized ALFF in the occipital areas. No significant correlation between the mini-mental state examination score and the standardized ALFF value was found in any brain region in the three frequency bands. Finally, no significant interaction between frequency bands and groups was found in any brain region. We concluded that the abnormality of spontaneous brain activity in acute mTBI patients existed in the frontal lobe as well as in distributed brain regions associated with integrative, sensory, and emotional roles, and the abnormal spontaneous neuronal activity in different brain regions could be better detected by the slow-4 band. These findings might contribute to a better understanding of local neural psychopathology of acute mTBI. Future studies should take the frequency bands into account when measuring intrinsic brain activity of mTBI patients.

Amplitude of low-frequency fluctuations in multiple-frequency bands in acute mild traumatic brain injury

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Jie eZhan

2016-02-01

Full Text Available Functional disconnectivity during the resting state has been observed in mild traumatic brain injury (mTBI patients during the acute stage. However, it remains largely unknown whether the abnormalities are related to specific frequency bands of the low-frequency oscillations (LFO. Here, we used the amplitude of low-frequency fluctuations (ALFF to examine the amplitudes of LFO in different frequency bands (slow-5: 0.01–0.027 Hz; slow-4: 0.027–0.073 Hz; and typical: 0.01–0.08 Hz in patients with acute mTBI. A total of 24 acute mTBI patients and 24 age-, sex-, and education-matched healthy controls (HC participated in this study. In the typical band, acute mTBI patients showed lower standardized ALFF in the right middle frontal gyrus and higher standardized ALFF in the right lingual/fusiform gyrus and left middle occipital gyrus. Further analyses showed that the difference between groups was concentrated in a narrower (slow-4 frequency band. In the slow-5 band, mTBI patients only exhibited higher standardized ALFF in the occipital areas. No significant correlation between the MMSE score and the standardized ALFF value was found in any brain region in the three frequency bands. Finally, no significant interaction between frequency bands and groups was found in any brain region. We concluded that the abnormality of spontaneous brain activity in acute mTBI patients existed in the frontal lobe as well as in distributed brain regions associated with integrative, sensory and emotional roles, and the abnormal spontaneous neuronal activity in different brain regions could be better detected by the slow-4 band. These findings might contribute to a better understanding of local neural psychopathology of acute mTBI. Future studies should take the frequency bands into account when measuring intrinsic brain activity of mTBI patients.

The autopsy-correlation of computed tomography in acute severe head injuries

International Nuclear Information System (INIS)

Tomita, Shin; Kim, Hong; Mikabe, Toshio; Karasawa, Hideharu; Watanabe, Saburo

1981-01-01

We discuss the importance of Contrast-Enhanced CT (C.E.CT) in establishing the variety of the intracranial pathological process in acute severe head injuries. During a two-and-a-half-year period (June, 1977 - December, 1979) thirty-three patients with acute severe head injuries were autopsied, all of whom had been scanned on admission. Among them, 14 patients had undergone both plain CT and C.E.CT on admission. Brain slices were examined macroscopically in three categories; brain contusion, subarachnoid hemorrhage, and intracerebral hemorrhage. Each category was then compared retrospectively with the plain CT and C.E.CT findings. C.E.CT was found to correspond much better to the autopsy finding than plain CT in the following three points: (1) C.E.CT clearly enhances the contusion areas and reveals occult contusion areas. (2) C.E.CT enhances the areas corresponding to the subarachnoid space due to the breakdown of brain-surface blood vessels. (3) C.E.CT reveals the enlargement and formation of the intracerebral hematoma by the extravasation of the intravenous contrast material from injured arterial vessels. (author)

Acute Psychosis Associated with Subcortical Stroke: Comparison between Basal Ganglia and Mid-Brain Lesions

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Aaron McMurtray

2014-01-01

Full Text Available Acute onset of psychosis in an older or elderly individual without history of previous psychiatric disorders should prompt a thorough workup for neurologic causes of psychiatric symptoms. This report compares and contrasts clinical features of new onset of psychotic symptoms between two patients, one with an acute basal ganglia hemorrhagic stroke and another with an acute mid-brain ischemic stroke. Delusions and hallucinations due to basal ganglia lesions are theorized to develop as a result of frontal lobe dysfunction causing impairment of reality checking pathways in the brain, while visual hallucinations due to mid-brain lesions are theorized to develop due to dysregulation of inhibitory control of the ponto-geniculate-occipital system. Psychotic symptoms occurring due to stroke demonstrate varied clinical characteristics that depend on the location of the stroke within the brain. Treatment with antipsychotic medications may provide symptomatic relief.

siRNA Treatment: “A Sword-in-the-Stone” for Acute Brain Injuries

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Jerome Badaut

2013-09-01

Full Text Available Ever since the discovery of small interfering ribonucleic acid (siRNA a little over a decade ago, it has been highly sought after for its potential as a therapeutic agent for many diseases. In this review, we discuss the promising possibility of siRNA to be used as a drug to treat acute brain injuries such as stroke and traumatic brain injury. First, we will give a brief and basic overview of the principle of RNA interference as an effective mechanism to decrease specific protein expression. Then, we will review recent in vivo studies describing siRNA research experiments/treatment options for acute brain diseases. Lastly, we will discuss the future of siRNA as a clinical therapeutic strategy against brain diseases and injuries, while addressing the current obstacles to effective brain delivery.

MRI findings of acute cerebral swelling and brain edema in the acute stage

International Nuclear Information System (INIS)

Oki, Hideo; Ueda, Shin; Matsumoto, Keizo; Kashihara, Michiharu; Furuichi, Masashi.

1988-01-01

We report two cases, one of acute cerebral swelling and the other with a major stroke, whose MRI has shown very interesting findings. Case 1, a 32-year-old male, was admitted to our service because of a lowering of his consciousness immediately after a head injury. On admission, the patient was semicomatous (E 1 M 2 V 1 , with anisocoria (R > L). His plain skull X-ray was normal. A CT scan, however, demonstrated right isodensity hemispheric swelling associated with a subarachnoid hemorrhage in the right Sylvian fissure. A right carotid angiogram showed no vascular disorders. MR imaging of the spin density demonstrated a hyperintensitive thickening of the gray matter in the whole right hemisphere. Case 2, a 58-year-old female, was admitted because of a sudden onset of loss of consciousness, with right hemiparesis and dysarthria. On admission, her consciousness was semicomatous (E 1 M 3 V 1 ), and it deteriorated to a deep coma 1 hour later. A CT scan demonstrated a diffuse left hemispheric low density, with a finding of hemorrhagic infarction in the basal ganglia. MR imaging of the spin density showed a hyperintensitive thickening of the gray matter resembling that of Case 1. The findings of the spin-echo images of our two cases showed a hyperintensitive thickening of the gray matter in both. The hyperintensity and thickening of the gray matter apparently indicated a sort of hyperemia and brain edema. These findings led us to suspect that the hyperemia associated with acute cerebral swelling and ischemic brain edema of our two cases originated in the gray matter, although it has been considered that the pathogenesis of acute cerebral swelling is not known and that brain edema, especially vasogenic edema, will mostly develop in the white matter rather than in the gray matter. (author)

Measurement of slice sensitivity profile for a 64-slice spiral CT system

International Nuclear Information System (INIS)

Liu Chuanya; Qin Weichang; Wang Wei; Lu Chuanyou

2006-01-01

Objective: To measure and evaluate slice sensitivity profile (SSP) and the full width at half-maximum(FWHM) for a 64-slice spiral CT system. Methods: Using the same CT technique and body mode as those used for clinical CT, delta phantom was scanned with Somatom Sensation 64-slice spiral CT. SSPs and FWHM were measured both with reconstruction slice width of 0.6 mm at pitch=0.50, 0.75, 1.00, 1.25, 1.50 and with reconstruction slice width of 0.6, 1.0, 1.5 mm at pitch=1 respectively. Results: For normal slice width of 0. 6 mm, the measured FWHM, i.e. effective slice width, is 0.67, 0.67, 0.66, 0.69, 0.69 mm at different pitch. All the measured FWHM deviate less than 0.1 mm from the nominal slice width. The measured SSPs are symmetrical, bell-shaped curves without far-reaching tails, and show only slight variations as a function of the spiral pitch. When reconstruction slice width increase, relative SSP become wider. Conclusions: The variation of pitch hardly has effect all on SSP, effective slice width, and z-direction spatial resolution for Sensation 64-slice spiral CT system, which is helpful to optimize CT scanning protocol. (authors)

Rat brain CYP2D enzymatic metabolism alters acute and chronic haloperidol side-effects by different mechanisms.

Science.gov (United States)

Miksys, Sharon; Wadji, Fariba Baghai; Tolledo, Edgor Cole; Remington, Gary; Nobrega, Jose N; Tyndale, Rachel F

2017-08-01

Risk for side-effects after acute (e.g. parkinsonism) or chronic (e.g. tardive dyskinesia) treatment with antipsychotics, including haloperidol, varies substantially among people. CYP2D can metabolize many antipsychotics and variable brain CYP2D metabolism can influence local drug and metabolite levels sufficiently to alter behavioral responses. Here we investigated a role for brain CYP2D in acutely and chronically administered haloperidol levels and side-effects in a rat model. Rat brain, but not liver, CYP2D activity was irreversibly inhibited with intracerebral propranolol and/or induced by seven days of subcutaneous nicotine pre-treatment. The role of variable brain CYP2D was investigated in rat models of acute (catalepsy) and chronic (vacuous chewing movements, VCMs) haloperidol side-effects. Selective inhibition and induction of brain, but not liver, CYP2D decreased and increased catalepsy after acute haloperidol, respectively. Catalepsy correlated with brain, but not hepatic, CYP2D enzyme activity. Inhibition of brain CYP2D increased VCMs after chronic haloperidol; VCMs correlated with brain, but not hepatic, CYP2D activity, haloperidol levels and lipid peroxidation. Baseline measures, hepatic CYP2D activity and plasma haloperidol levels were unchanged by brain CYP2D manipulations. Variable rat brain CYP2D alters side-effects from acute and chronic haloperidol in opposite directions; catalepsy appears to be enhanced by a brain CYP2D-derived metabolite while the parent haloperidol likely causes VCMs. These data provide novel mechanistic evidence for brain CYP2D altering side-effects of haloperidol and other antipsychotics metabolized by CYP2D, suggesting that variation in human brain CYP2D may be a risk factor for antipsychotic side-effects. Copyright © 2017 Elsevier Inc. All rights reserved.

Activation of PAF-synthesizing enzymes in rat brain stem slices after LTP induction in the medial vestibular nuclei.

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Francescangeli, Ermelinda; Grassi, Silvarosa; Pettorossi, Vito E; Goracci, Gianfrancesco

2002-11-01

LysoPAF acetyltransferase (lysoPAF-AT) and PAF-synthesizing phosphocholinetransferase (PAF-PCT) are the two enzymes which catalyze the final reactions for the synthesis of PAF. Their activities, assayed in the homogenate of rat brain stem slices and under their optimal conditions, increased 5 min after high frequency stimulation of vestibular afferents, inducing LTP in the medial vestibular nuclei. The activity of phosphatidylcholine-synthesizing phosphocholinetransferase, was not affected. Sixty minutes from the induction of LTP, PAF-PCT activity, but not that of lysoPAF-AT, was still significantly higher with respect to 5 min test stimulated control. We used AP-5 to verify whether this increase was strictly dependent upon LTP induction, which requires NMDA receptor activation. In AP-5 treated slices, lysoPAF-acetyltransferase and PAF-synthesizing phosphocholinetransferase activities increased, but they were reduced after high frequency stimulation under AP-5. In conclusion, we have demonstrated that the activities of PAF-synthesizing enzymes are activated soon after the induction of LTP and that this effect is linked to the activation of NMDA-receptors. We suggest that the enzyme activation by AP-5, preventing LTP, might be due to glutamate enhancement but, in neurons showing LTP and under normal conditions, the activation of potentiation mechanisms is critical for the enhancement of enzyme activities.

Prevention and management of brain edema in patients with acute liver failure

DEFF Research Database (Denmark)

Wendon, J.; Larsen, Finn Stolze

2008-01-01

1. Intracranial pressure is the pressure exerted by the cranial contents on the dural envelope and consists of the partial pressures of the brain, blood, and cerebrospinal fluid. 2. Severe cases of acute liver failure are frequently complicated by brain edema (due to cytotoxic edema...

Thick Slice and Thin Slice Teaching Evaluations

Science.gov (United States)

Tom, Gail; Tong, Stephanie Tom; Hesse, Charles

2010-01-01

Student-based teaching evaluations are an integral component to institutions of higher education. Previous work on student-based teaching evaluations suggest that evaluations of instructors based upon "thin slice" 30-s video clips of them in the classroom correlate strongly with their end of the term "thick slice" student evaluations. This study's…

Architectural slicing

DEFF Research Database (Denmark)

Christensen, Henrik Bærbak; Hansen, Klaus Marius

2013-01-01

Architectural prototyping is a widely used practice, con- cerned with taking architectural decisions through experiments with light- weight implementations. However, many architectural decisions are only taken when systems are already (partially) implemented. This is prob- lematic in the context...... of architectural prototyping since experiments with full systems are complex and expensive and thus architectural learn- ing is hindered. In this paper, we propose a novel technique for harvest- ing architectural prototypes from existing systems, \\architectural slic- ing", based on dynamic program slicing. Given...... a system and a slicing criterion, architectural slicing produces an architectural prototype that contain the elements in the architecture that are dependent on the ele- ments in the slicing criterion. Furthermore, we present an initial design and implementation of an architectural slicer for Java....

Impact of Different CT Slice Thickness on Clinical Target Volume for 3D Conformal Radiation Therapy

International Nuclear Information System (INIS)

Prabhakar, Ramachandran; Ganesh, Tharmar; Rath, Goura K.; Julka, Pramod K.; Sridhar, Pappiah S.; Joshi, Rakesh C.; Thulkar, Sanjay

2009-01-01

The purpose of this study was to present the variation of clinical target volume (CTV) with different computed tomography (CT) slice thicknesses and the impact of CT slice thickness on 3-dimensional (3D) conformal radiotherapy treatment planning. Fifty patients with brain tumors were selected and CT scans with 2.5-, 5-, and 10-mm slice thicknesses were performed with non-ionic contrast enhancement. The patients were selected with tumor volume ranging from 2.54 cc to 222 cc. Three-dimensional treatment planning was performed for all three CT datasets. The target coverage and the isocenter shift between the treatment plans for different slice thickness were correlated with the tumor volume. An important observation from our study revealed that for volume 25 cc, the target underdosage was less than 6.7% for 5-mm slice thickness and 8% for 10-mm slice thickness. For 3D conformal radiotherapy treatment planning (3DCRT), a CT slice thickness of 2.5 mm is optimum for tumor volume 25 cc

Bacterial cytolysin during meningitis disrupts the regulation of glutamate in the brain, leading to synaptic damage.

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Carolin Wippel

Full Text Available Streptococcus pneumoniae (pneumococcal meningitis is a common bacterial infection of the brain. The cholesterol-dependent cytolysin pneumolysin represents a key factor, determining the neuropathogenic potential of the pneumococci. Here, we demonstrate selective synaptic loss within the superficial layers of the frontal neocortex of post-mortem brain samples from individuals with pneumococcal meningitis. A similar effect was observed in mice with pneumococcal meningitis only when the bacteria expressed the pore-forming cholesterol-dependent cytolysin pneumolysin. Exposure of acute mouse brain slices to only pore-competent pneumolysin at disease-relevant, non-lytic concentrations caused permanent dendritic swelling, dendritic spine elimination and synaptic loss. The NMDA glutamate receptor antagonists MK801 and D-AP5 reduced this pathology. Pneumolysin increased glutamate levels within the mouse brain slices. In mouse astrocytes, pneumolysin initiated the release of glutamate in a calcium-dependent manner. We propose that pneumolysin plays a significant synapto- and dendritotoxic role in pneumococcal meningitis by initiating glutamate release from astrocytes, leading to subsequent glutamate-dependent synaptic damage. We outline for the first time the occurrence of synaptic pathology in pneumococcal meningitis and demonstrate that a bacterial cytolysin can dysregulate the control of glutamate in the brain, inducing excitotoxic damage.

An associative Brain-Computer-Interface for acute stroke patients

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Mrachacz-Kersting, Natalie; Stevenson, Andrew James Thomas; Aliakbaryhosseinabadi, Susan

2016-01-01

An efficient innovative Brain-Computer-Interface system that empowers chronic stroke patients to control an artificial activation of their lower limb muscle through task specific motor intent has been tested in the past. In the current study it was applied to acute stroke patients. The system...

Time- and dose-dependent changes in neuronal activity produced by X radiation in brain slices

International Nuclear Information System (INIS)

Pellmar, T.C.; Schauer, D.A.; Zeman, G.H.

1990-01-01

A new method of exposing tissues to X rays in a lead Faraday cage has made it possible to examine directly radiation damage to isolated neuronal tissue. Thin slices of hippocampus from brains of euthanized guinea pigs were exposed to 17.4 ke V X radiation. Electrophysiological recordings were made before, during, and after exposure to doses between 5 and 65 Gy at a dose rate of 1.54 Gy/min. Following exposure to doses of 40 Gy and greater, the synaptic potential was enhanced, reaching a steady level soon after exposure. The ability of the synaptic potential to generate a spike was reduced and damage progressed after termination of the radiation exposure. Recovery was not observed following termination of exposure. These results demonstrate that an isolated neuronal network can show complex changes in electrophysiological properties following moderate doses of ionizing radiation. An investigation of radiation damage directly to neurons in vitro will contribute to the understanding of the underlying mechanisms of radiation-induced nervous system dysfunction

Novel Mechanism for Reducing Acute and Chronic Neurodegeneration After Traumatic Brain Injury

Science.gov (United States)

2017-07-01

Award Number: W81XWH-14-1-0195 TITLE: Novel Mechanism for Reducing Acute and Chronic Neurodegeneration after Traumatic Brain Injury...Purpose: The purpose of this project is to develop a radically different strategy to reduce brain glutamate excitotoxicity and treat TBI. We will...objective of reducing blood levels of glutamate. This will produce a brain -to-blood gradient of glutamate which will enhance the removal of excess

Change in brain magnetic resonance spectroscopy after treatment during acute HIV infection.

Science.gov (United States)

Sailasuta, Napapon; Ross, William; Ananworanich, Jintanat; Chalermchai, Thep; DeGruttola, Victor; Lerdlum, Sukalaya; Pothisri, Mantana; Busovaca, Edgar; Ratto-Kim, Silvia; Jagodzinski, Linda; Spudich, Serena; Michael, Nelson; Kim, Jerome H; Valcour, Victor

2012-01-01

Single voxel proton magnetic resonance spectroscopy (MRS) can be used to monitor changes in brain inflammation and neuronal integrity associated with HIV infection and its treatments. We used MRS to measure brain changes during the first weeks following HIV infection and in response to antiretroviral therapy (ART). Brain metabolite levels of N-acetyl aspartate (NAA), choline (tCHO), creatine (CR), myoinositol (MI), and glutamate and glutamine (GLX) were measured in acute HIV subjects (n = 31) and compared to chronic HIV+individuals (n = 26) and HIV negative control subjects (n = 10) from Bangkok, Thailand. Metabolites were measured in frontal gray matter (FGM), frontal white matter (FWM), occipital gray matter (OGM), and basal ganglia (BG). Repeat measures were obtained in 17 acute subjects 1, 3 and 6 months following initiation of ART. After adjustment for age we identified elevated BG tCHO/CR in acute HIV cases at baseline (median 14 days after HIV infection) compared to control (p = 0.0014), as well as chronic subjects (p = 0.0023). A similar tCHO/CR elevation was noted in OGM; no other metabolite abnormalities were seen between acute and control subjects. Mixed longitudinal models revealed resolution of BG tCHO/CR elevation after ART (p = 0.022) with tCHO/CR similar to control subjects at 6 months. We detected cellular inflammation in the absence of measurable neuronal injury within the first month of HIV infection, and normalization of this inflammation following acutely administered ART. Our findings suggest that early ART may be neuroprotective in HIV infection by mitigating processes leading to CNS injury.

MR imaging of acute hemorrhagic brain infarction

International Nuclear Information System (INIS)

Uchino, Akira; Ohnari, Norihiro; Ohno, Masato

1989-01-01

Six patients with acute hemorrhagic brain infarct were imaged using spin-echo (SE) pulse sequences on a 1.5 Tesla MR scanner. Including two patients with repeated MR imaging, a total of eight examinations, all performed within 15 days after stroke, were analyzed retrospectively. Four patients revealed massive hemorrhages in the basal ganglia or cerebellum and three cases demonstrated multiple linear hemorrhages in the cerebral cortex. On T1-weighted images, hemorrhages were either mildly or definitely hyperintense relative to gray matter, while varied from mildly hypointense to hyperintense on T2-weighted images. T1-weighted images were superior to T2-weighted images in detection of hemorrhgage. CT failed to detect hemorrhage in two of five cases: indicative of MR superiority to CT in the diagnosis of acute hemorrhagic infarcts. (author)

Nonlinear Dynamic Theory of Acute Cell Injuries and Brain Ischemia

Science.gov (United States)

Taha, Doaa; Anggraini, Fika; Degracia, Donald; Huang, Zhi-Feng

2015-03-01

Cerebral ischemia in the form of stroke and cardiac arrest brain damage affect over 1 million people per year in the USA alone. In spite of close to 200 clinical trials and decades of research, there are no treatments to stop post-ischemic neuron death. We have argued that a major weakness of current brain ischemia research is lack of a deductive theoretical framework of acute cell injury to guide empirical studies. A previously published autonomous model based on the concept of nonlinear dynamic network was shown to capture important facets of cell injury, linking the concept of therapeutic to bistable dynamics. Here we present an improved, non-autonomous formulation of the nonlinear dynamic model of cell injury that allows multiple acute injuries over time, thereby allowing simulations of both therapeutic treatment and preconditioning. Our results are connected to the experimental data of gene expression and proteomics of neuron cells. Importantly, this new model may be construed as a novel approach to pharmacodynamics of acute cell injury. The model makes explicit that any pro-survival therapy is always a form of sub-lethal injury. This insight is expected to widely influence treatment of acute injury conditions that have defied successful treatment to date. This work is supported by NIH NINDS (NS081347) and Wayne State University President's Research Enhancement Award.

Acute Respiratory Distress Syndrome in Severe Brain Injury

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Yu. A. Churlyaev

2009-01-01

Full Text Available Objective: to study the development of acute respiratory distress syndrome (ARDS in victims with isolated severe brain injury (SBI. Subject and methods. 171 studies were performed in 16 victims with SBI. Their general condition was rated as very critical. The patients were divided into three groups: 1 non-ARDS; 2 Stage 1 ARDS; and 3 Stage 2 ARDS. The indicators of Stages 1 and 2 were assessed in accordance with the classification proposed by V. V. Moroz and A. M. Golubev. Intracranial pressure (ICP, extravascular lung water index, pulmonary vascular permeability, central hemodynamics, oxygenation index, lung anastomosis, the X-ray pattern of the lung and brain (computed tomography, and its function were monitored. Results. The hemispheric cortical level of injury of the brain with function compensation of its stem was predominantly determined in the controls; subcompensation and decompensation were ascertained in the ARDS groups. According to the proposed classification, these patients developed Stages 1 and 2 ARDS. When ARDS developed, there were rises in the level of extravascular lung fluid and pulmonary vascular permeability, a reduction in the oxygenation index (it was 6—12 hours later as compared with them, increases in a lung shunt and ICP; X-ray study revealed bilateral infiltrates in the absence of heart failure in Stage 2 ARDS. The correlation was positive between ICP and extravascular lung water index, and lung vascular permeability index (r>0.4;p<0.05. Conclusion. The studies have indicated that the classification proposed by V. V. Moroz and A. M. Golubev enables an early diagnosis of ARDS. One of its causes is severe brainstem injury that results in increased extravascular fluid in the lung due to its enhanced vascular permeability. The ICP value is a determinant in the diagnosis of secondary brain injuries. Key words: acute respiratory distress syndrome, extravascu-lar lung fluid, pulmonary vascular permeability, brain injury

Heterogeneity of brain blood flow and permeability during acute hypertension

International Nuclear Information System (INIS)

Baumbach, G.L.; Heistad, D.D.

1985-01-01

The purpose of this study was to examine regional autoregulation of blood flow in the brain during acute hypertension. In anesthetized cats severe hypertension increased blood flow more in cerebrum (159%) and cerebellum (106%) than brain stem (58%). In contrast to the heterogeneous autoregulatory response, hypocapnia produced uniform vasoconstriction in the brain. The authors also compared vasodilatation during severe hypertension with vasodilatation during hypercapnia. During hypercapnia, blood flow increased as much in brain stem, as in cerebrum and cerebellum. Thus, regional differences in autoregulation appear to be specific for autoregulatory stimulus and are not secondary to nonspecific differences in vasoconstrictor or vasodilator capacity. To determine whether the blood-brain barrier is more susceptible to hypertensive disruption in regions with less effective autoregulation, permeability of the barrier was quantitated with 125 I-albumin. Severe hypertension produced disruption of the barrier in cerebrum but not in brain stem. Thus, there are parallel differences in effectiveness of autoregulation and susceptibility to disruption of the blood-brain barrier in different regions of the brain

Excitotoxic effects of non-NMDA receptor agonists in organotypic corticostriatal slice cultures

DEFF Research Database (Denmark)

Kristensen, B W; Noraberg, J; Jakobsen, B

1999-01-01

of the cytosolic enzyme lactate dehydrogenase (LDH) into the culture medium and loss of glutamic acid decarboxylase (GAD) activity in the tissue. Histological sections were also stained by the fluorescent dye Fluoro-Jade (FJ), for degenerating neurons and by immunocytochemical staining for gamma-aminobutyric acid...... density of Fluoro-Jade staining, (3) loss of GAD-activity in tissue homogenates, and (4) loss of GABA-immunostained neurons. We conclude that both differences between compounds (AMPA vs. KA) and brain areas (striatum vs. cortex) can be demonstrated in corticostriatal slice cultures, which in conjunction...... in corticostriatal slice cultures. The purpose was to examine the feasibility of these cultures for excitotoxic studies, and to demonstrate possible differential excitotoxic effects of KA and AMPA on striatal and cortical neurons. Slices of dorsolateral striatum with overlying neocortex were obtained from neonatal...

Outline and handling manual of experimental data time slice monitoring software 'SLICE'

International Nuclear Information System (INIS)

Shirai, Hiroshi; Hirayama, Toshio; Shimizu, Katsuhiro; Tani, Keiji; Azumi, Masafumi; Hirai, Ken-ichiro; Konno, Satoshi; Takase, Keizou.

1993-02-01

We have developed a software 'SLICE' which maps various kinds of plasma experimental data measured at the different geometrical position of JT-60U and JFT-2M onto the equilibrium magnetic configuration and treats them as a function of volume averaged minor radius ρ. Experimental data can be handled uniformly by using 'SLICE'. Plenty of commands of 'SLICE' make it easy to process the mapped data. The experimental data measured as line integrated values are also transformed by Abel inversion. The mapped data are fitted to a functional form and saved to the database 'MAPDB'. 'SLICE' can read the data from 'MAPDB' and re-display and transform them. Still more 'SLICE' creates run data of orbit following Monte-Carlo code 'OFMC' and tokamak predictive and interpretation code system 'TOPICS'. This report summarizes an outline and the usage of 'SLICE'. (author)

The clinical usefulness of Tc-99m ECD brain SPECT in acute measles encephalitis

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Lim, Seok Tae; Sohn, Myung Hee [School of Medicine, Chonbuk National Univ., Chonju (Korea, Republic of)

2003-08-01

Since the prognosis of measles encephalitis is poor, early diagnosis and proper management are very important to improve clinical outcomes. We compared Tc-99m ECD brain SPECT (SPECT) with MR imaging (MRI) for the detection of acute measles encephalitis. Eleven patients (M : F=4 : 7, age range 18 months-14 yrs) with acute measles encephalitis were enrolled in this studies. All of them underwent both MRI and SPECT. The results of SPECT were scored from 0 (normal) to 3 (most severe defect) according to perfusion state. We compared two image modalities for the detection of brain abnormality in acute measles encephalitis. Seven of 11 patients (63.6%) revealed high signal intensity in the white matter on T2WI of MRI, on the other hand all patients (100%) showed hypoperfusion on SPECT. Severe perfusion deficits above score 2 were located with decreasing frequencies in the frontal lobe (81.8%), temporal lobe (72.7%), occipital lobe (27.3%), basal ganglia (27.3%), and parietal lobe (9.1%). We conclude that SPECT is more useful than MRI for the detection of brain involvement in patients with acute measles encephalitis.

The clinical usefulness of Tc-99m ECD brain SPECT in acute measles encephalitis

International Nuclear Information System (INIS)

Lim, Seok Tae; Sohn, Myung Hee

2003-01-01

Since the prognosis of measles encephalitis is poor, early diagnosis and proper management are very important to improve clinical outcomes. We compared Tc-99m ECD brain SPECT (SPECT) with MR imaging (MRI) for the detection of acute measles encephalitis. Eleven patients (M : F=4 : 7, age range 18 months-14 yrs) with acute measles encephalitis were enrolled in this studies. All of them underwent both MRI and SPECT. The results of SPECT were scored from 0 (normal) to 3 (most severe defect) according to perfusion state. We compared two image modalities for the detection of brain abnormality in acute measles encephalitis. Seven of 11 patients (63.6%) revealed high signal intensity in the white matter on T2WI of MRI, on the other hand all patients (100%) showed hypoperfusion on SPECT. Severe perfusion deficits above score 2 were located with decreasing frequencies in the frontal lobe (81.8%), temporal lobe (72.7%), occipital lobe (27.3%), basal ganglia (27.3%), and parietal lobe (9.1%). We conclude that SPECT is more useful than MRI for the detection of brain involvement in patients with acute measles encephalitis

The effects of slice thickness and reconstructive parameters on VR image quality in multi-slice CT

International Nuclear Information System (INIS)

Gao Zhenlong; Wang Qiang; Liu Caixia

2005-01-01

Objective: To explore the effects of slice thickness, reconstructive thickness and reconstructive interval on VR image quality in multi-slice CT, in order to select the best slice thickness and reconstructive parameters for the imaging. Methods: Multi-slice CT scan was applied on a rubber dinosaur model with different slice thickness. VR images were reconstructed with different reconstructive thickness and reconstructive interval. Five radiologists were invited to evaluate the quality of the images without knowing anything about the parameters. Results: The slice thickness, reconstructive thickness and reconstructive interval did have effects on VR image quality and the effective degree was different. The effective coefficients were V 1 =1413.033, V 2 =563.733, V 3 =390.533, respectively. The parameters interacted with the others (P<0.05). The smaller of those parameters, the better of the image quality. With a small slice thickness and a reconstructive slice equal to slice thickness, the image quality had no obvious difference when the reconstructive interval was 1/2, 1/3, 1/4 of the slice thickness. Conclusion: A relative small scan slice thickness, a reconstructive slice equal to slice thickness and a reconstructive interval 1/2 of the slice thickness should be selected for the best VR image quality. The image quality depends mostly on the slice thickness. (authors)

GDNF and neublastin protect against NMDA-induced excitotoxicity in hippocampal slice cultures

DEFF Research Database (Denmark)

Bonde, C; Kristensen, B W; Blaabjerg, M

2000-01-01

-producing HiB5 cells, were added to slice cultures I h before exposure to 10 microM NMDA for 48h. Neuronal cell death was monitored, before and during the NMDA exposure, by densitometric measurements of propidium iodide (PI) uptake and loss of Nissl staining. Both the addition of rhGDNF and NBN......The potential neuroprotective effects of glial cell line-derived neurotrophic factor (GDNF) and neublastin (NBN) against NMDA-induced excitotoxicity were examined in hippocampal brain slice cultures. Recombinant human GDNF (25-100 ng/ ml) or NBN, in medium conditioned by growth of transfected, NBN...

Acute Cocaine Exposure elicits rises in calcium in Arousal Related Laterodorsal Tegmental Neurons

DEFF Research Database (Denmark)

Lambert, Mads; Ipsen, Theis; Kohlmeier, Kristi Anne

2017-01-01

Cocaine has strong reinforcing properties, which underlie its high addiction potential. Reinforcement of use of addictive drugs is associated with rises in dopamine (DA) in mesoaccumbal circuitry. Excitatory afferent input to mesoaccumbal circuitry sources from the laterodorsal tegmental nucleus...... (LDT). Chronic, systemic cocaine exposure has been shown to have cellular effects on LDT cells, but acute actions of local application have never been demonstrated. Using calcium imaging, we show that acute application of cocaine to mouse brain slices induces calcium spiking in cells of the LDT....... Spiking was attenuated by tetrodotoxin (TTX) and low calcium solutions, and abolished by prior exhaustion of intracellular calcium stores. Further, DA receptor antagonists reduced these transients, whereas DA induced rises with similar spiking kinetics. Amphetamine, which also results in elevated levels...

The value of brain CT findings in acute methanol toxicity

International Nuclear Information System (INIS)

Taheri, Morteza Sanei; Moghaddam, Hossein Hassanian; Moharamzad, Yashar; Dadgari, Shahrzad; Nahvi, Vahideh

2010-01-01

Objective: Due to depressant effects of methanol on the central nervous system, brain computed tomography (CT) scan has been introduced as a diagnostic device in methanol intoxication. The authors aimed to present brain CT findings in patients with acute methanol intoxication and to determine signs associated with death. Materials and methods: This cohort study involved 42 consecutive patients with acute methanol intoxication. Inclusion criteria were consisted of characteristic clinical presentation of methanol poisoning, and metabolic acidosis with increased anion and osmolar gaps. Brain CT scans without contrast medium were obtained. To determine the association between the CT findings and death, the chi-square test or the Fisher's exact test, odds ratio (OR) and its 95% confidence interval (95% CI) were calculated. Results: Twenty-eight patients (66.6%) had a total of 55 abnormal findings on brain CT, in which bilateral putaminal hypodense lesions was the most common manifestation (27 cases, 96.4%). Putaminal hemorrhage with varying degrees was observed in 7 patients (25%). Six patients (21.4%) had low attenuation lesions in the subcortical white matter of the insula. A significant association was observed between putaminal hemorrhage (OR = 8, 95% CI = 1.187-53.93, P = 0.018) and subcortical necrosis of the insula (OR = 11, 95% CI = 1.504-80.426, P = 0.007) with death. Conclusion: In addition to clinical and laboratory findings, presence of putaminal hemorrhage and insular subcortex white matter necrosis are associated with a poor clinical outcome in patients with methanol poisoning.

MR imaging of brain tissue changes in acute and chronic solvent intoxication

International Nuclear Information System (INIS)

Rinck, P.A.; Nilsen, G.; Kvaerness, J.

1988-01-01

Acute and chronic intoxication with solvents is found both as an occupational hazard and as self-inflicted in addicts to solvent. Objective demonstration of such brain tissue changes is difficult with conventional imaging methods, and in most cases findings are negative. In a preliminary study, the brains of eight patients (aged 28-62 years) exposed to aggressive solvents for 1-27 years were examined with magnetic resonance imaging. All of the patients showed brain atrophy of varying extent, and seven of eight patients (all except the youngest and least exposed) had brain lesions that somewhat resembled dymyelinating changes (focal and confluent periventricular and deep white matter lesions, brain stem and cerebellar lesions); one patient showed cloudy, poorly defined lesions

Hypo-and hyperthyroidism affect the ATP, ADP and AMP hydrolysis in rat hippocampal and cortical slices.

Science.gov (United States)

Bruno, Alessandra Nejar; Diniz, Gabriela Placoná; Ricachenevsky, Felipe Klein; Pochmann, Daniela; Bonan, Carla Denise; Barreto-Chaves, Maria Luiza M; Sarkis, João José Freitas

2005-05-01

The presence of severe neurological symptoms in thyroid diseases has highlighted the importance of thyroid hormones in the normal functioning of the mature brain. Since, ATP is an important excitatory neurotransmitter and adenosine acts as a neuromodulatory structure inhibiting neurotransmitters release in the central nervous system (CNS), the ectonucleotidase cascade that hydrolyzes ATP to adenosine, is also involved in the control of brain functions. Thus, we investigated the influence of hyper-and hypothyroidism on the ATP, ADP and AMP hydrolysis in hippocampal and cortical slices from adult rats. Hyperthyroidism was induced by daily injections of l-thyroxine (T4) 25 microg/100 g body weight, for 14 days. Hypothyroidism was induced by thyroidectomy and methimazole (0.05%) added to their drinking water for 14 days. Hypothyroid rats were hormonally replaced by daily injections of T4 (5 microg/100 g body weight, i.p.) for 5 days. Hyperthyroidism significantly inhibited the ATP, ADP and AMP hydrolysis in hippocampal slices. In brain cortical slices, hyperthyroidism inhibited the AMP hydrolysis. In contrast, hypothyroidism increased the ATP, ADP and AMP hydrolysis in both hippocampal and cortical slices and these effects were reverted by T4 replacement. Furthermore, hypothyroidism increased the expression of NTPDase1 and 5'-nucleotidase, whereas hyperthyroidism decreased the expression of 5'-nucleotidase in hippocampus of adult rats. These findings demonstrate that thyroid disorders may influence the enzymes involved in the complete degradation of ATP to adenosine and possibly affects the responses mediated by adenine nucleotides in the CNS of adult rats.

Effects of Administration of Perinatal Bupropion on the Population Spike Amplitude in Neonatal Rat Hippocampal Slice

Directory of Open Access Journals (Sweden)

Soomaayeh Heysieat-talab

2010-09-01

Full Text Available Objective(sBupropion is an atypical antidepressant that is widely used in smoke cessation under FDA approval. The study of synaptic effects of bupropion can help to finding out its mechanism(s for stopping nicotine dependence. In this study the effects of perinatal bupropion on the population spike (PS amplitude of neonates were investigated. Materials and Methods Hippocampal slices were prepared from 18-25 days old rat pups. The experimental groups included control and bupropion-treated. Bupropion (40 mg/Kg, i.p. was applied daily in perinatal period as pre-treatment. Due to the studying acute effects, bupropion was also added to the perfusion medium (10, 50, 200 μM for 30 min. The evoked PS was recorded from pyramidal layer of CA1 area, following stimulation of Schaffer collaterals. ResultsA concentration of 10 μM bupropion had no significant effects on the PS amplitude. The 50 μM concentration of bupropion reduced the amplitude of responses in 50% of the studied cases. At a concentration of 200 μM, the recorded PS amplitudes were reduced in all slices (n= 22. Amplitude was completely abolished in 8 out of the 22 slices. The decrease of the PS amplitude was found to be more in the non-pre-treated slices than in the pre-treated slices when both were perfused with 200 μM bupropion.Conclusion The results showed the perinatal exposure to bupropion and its acute effects while indicating that at concentrations of 50 and 200 μM bupropion reduced the PS amplitude. It was also found that there was evidence of synaptic adaptation in comparison of bupropion-treated and non-treated slices whereas they were both perfused with 200 µM.

Altered brain function in new onset childhood acute lymphoblastic leukemia before chemotherapy: A resting-state fMRI study.

Science.gov (United States)

Hu, Zhanqi; Zou, Dongfang; Mai, Huirong; Yuan, Xiuli; Wang, Lihong; Li, Yue; Liao, Jianxiang; Liu, Liwei; Liu, Guosheng; Zeng, Hongwu; Wen, Feiqiu

2017-10-01

Cognitive impairments had been reported in childhood acute lymphoblastic leukemia, what caused the impairments needed to be demonstrated, chemotherapy-related or the disease itself. The primary aim of this exploratory investigation was to determine if there were changes in brain function of children with acute lymphoblastic leukemia before chemotherapy. In this study, we advanced a measure named regional homogeneity to evaluate the resting-state brain activities, intelligence quotient test was performed at same time. Using regional homogeneity, we first investigated the resting state brain function in patients with new onset childhood acute lymphoblastic leukemia before chemotherapy, healthy children as control. The decreased ReHo values were mainly founded in the default mode network and left frontal lobe, bilateral inferior parietal lobule, bilateral temporal lobe, bilateral occipital lobe, precentral gyrus, bilateral cerebellum in the newly diagnosed acute lymphoblastic leukemia patients compared with the healthy control. While in contrast, increased ReHo values were mainly shown in the right frontal lobe (language area), superior frontal gyrus-R, middle frontal gyrus-R and inferior parietal lobule-R for acute lymphoblastic leukemia patients group. There were no significant differences for intelligence quotient measurements between the acute lymphoblastic leukemia patient group and the healthy control in performance intelligence quotient, verbal intelligence quotient, total intelligence quotient. The altered brain functions are associated with cognitive change and language, it is suggested that there may be cognition impairment before the chemotherapy. Regional homogeneity by functional magnetic resonance image is a sensitive way for early detection on brain damage in childhood acute lymphoblastic leukemia. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Imaging findings of the brain abnormalities in acute lymphoblastic leukemia of children during and after treatment

International Nuclear Information System (INIS)

Lee, Kyung Joo; Lee, Seung Rho; Park, Dong Woo; Joo, Kyung Bin; Kim, Jang Wook; Hahm, Chang Kok; Kim, Ki Joong; Lee, Hahng

2001-01-01

We evaluated the imaging abnormalities of the brain observed during and after treatment of acute childhood lymphoblastic leukemia. The study group consisted of 30 patients (male : female=19 : 11 ; mean age, 64 months) with acute childhood lymphoblastic leukemia during the previous ten-year period who had undergone prophylaxis of the central nervous system. Irrespective of the CNS symptoms, base-line study of the brain involving CT and follow-up CT or MRI was undertaken more than once. We retrospectively evaluated the imaging findings, methods of treatment, associated CNS symptoms, and the interval between diagnosis and the time at which brain abnormalities were revealed by imaging studies. In 15 (50% ; male : female=9 : 6 ; mean age, 77 months) of 30 patients, brain abnormalities that included brain atrophy (n=9), cerebral infarctions (n=4), intracranial hemorrhage (n=1), mineralizing microangiopathy (n=2), and periventricular leukomalacia (n=3) were seen on follow-up CT or MR images. In four of nine patients with brain atrophy, imaging abnormalities such as periventricular leukomalacia (n=2), infarction (n=1) and microangiopathy (n=1) were demonstrated. Fourteen of the 15 patients underwent similar treatment ; the one excluded had leukemic cells in the CSF. Six patients had CNS symptoms. In the 15 patients with abnormal brain imaging findings, the interval between diagnosis and the demonstration of brain abnormalities was between one month and four years. After the cessation of treatment, imaging abnormalities remained in all patients except one with brain atrophy. Various imaging abnormalities of the brain may be seen during and after the treatment of acute childhood lymphoblastic leukemia and persist for a long time. In children with this condition, the assessment of brain abnormalities requires follow-up study of the brain

Imaging findings of the brain abnormalities in acute lymphoblastic leukemia of children during and after treatment

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Lee, Kyung Joo; Lee, Seung Rho; Park, Dong Woo; Joo, Kyung Bin; Kim, Jang Wook; Hahm, Chang Kok; Kim, Ki Joong; Lee, Hahng [College of Medicine, Hanyang Univ., Seoul (Korea, Republic of)

2001-09-01

We evaluated the imaging abnormalities of the brain observed during and after treatment of acute childhood lymphoblastic leukemia. The study group consisted of 30 patients (male : female=19 : 11 ; mean age, 64 months) with acute childhood lymphoblastic leukemia during the previous ten-year period who had undergone prophylaxis of the central nervous system. Irrespective of the CNS symptoms, base-line study of the brain involving CT and follow-up CT or MRI was undertaken more than once. We retrospectively evaluated the imaging findings, methods of treatment, associated CNS symptoms, and the interval between diagnosis and the time at which brain abnormalities were revealed by imaging studies. In 15 (50% ; male : female=9 : 6 ; mean age, 77 months) of 30 patients, brain abnormalities that included brain atrophy (n=9), cerebral infarctions (n=4), intracranial hemorrhage (n=1), mineralizing microangiopathy (n=2), and periventricular leukomalacia (n=3) were seen on follow-up CT or MR images. In four of nine patients with brain atrophy, imaging abnormalities such as periventricular leukomalacia (n=2), infarction (n=1) and microangiopathy (n=1) were demonstrated. Fourteen of the 15 patients underwent similar treatment ; the one excluded had leukemic cells in the CSF. Six patients had CNS symptoms. In the 15 patients with abnormal brain imaging findings, the interval between diagnosis and the demonstration of brain abnormalities was between one month and four years. After the cessation of treatment, imaging abnormalities remained in all patients except one with brain atrophy. Various imaging abnormalities of the brain may be seen during and after the treatment of acute childhood lymphoblastic leukemia and persist for a long time. In children with this condition, the assessment of brain abnormalities requires follow-up study of the brain.

Cognitive activity limitations one year post-trauma in patients admitted to sub-acute rehabilitation after severe traumatic brain injury

DEFF Research Database (Denmark)

Sommer, Jens Bak; Norup, Anne; Poulsen, Ingrid

2013-01-01

Objective: To examine cognitive activity limitations and predictors of outcome 1 year post-trauma in patients admitted to sub-acute rehabilitation after severe traumatic brain injury. Subjects: The study included 119 patients with severe traumatic brain injury admitted to centralized sub-acute re......Objective: To examine cognitive activity limitations and predictors of outcome 1 year post-trauma in patients admitted to sub-acute rehabilitation after severe traumatic brain injury. Subjects: The study included 119 patients with severe traumatic brain injury admitted to centralized sub......-acute rehabilitation in the Eastern part of Denmark during a 5-year period from 2005 to 2009. Methods: Level of consciousness was assessed consecutively during rehabilitation and at 1 year post-trauma. Severity of traumatic brain injury was classified according to duration of post-traumatic amnesia. The cognitive...... subscale of Functional Independence MeasureTM (Cog-FIM) was used to assess cognitive activity limitations. Multivariate logistic regression analyses were performed to identify predictors of an independent level of functioning. Results: The majority of patients progressed to a post-confusional level...

Use of pattern recognition for unaliasing simultaneously acquired slices in simultaneous multislice MR fingerprinting.

Science.gov (United States)

Jiang, Yun; Ma, Dan; Bhat, Himanshu; Ye, Huihui; Cauley, Stephen F; Wald, Lawrence L; Setsompop, Kawin; Griswold, Mark A

2017-11-01

The purpose of this study is to accelerate an MR fingerprinting (MRF) acquisition by using a simultaneous multislice method. A multiband radiofrequency (RF) pulse was designed to excite two slices with different flip angles and phases. The signals of two slices were driven to be as orthogonal as possible. The mixed and undersampled MRF signal was matched to two dictionaries to retrieve T 1 and T 2 maps of each slice. Quantitative results from the proposed method were validated with the gold-standard spin echo methods in a phantom. T 1 and T 2 maps of in vivo human brain from two simultaneously acquired slices were also compared to the results of fast imaging with steady-state precession based MRF method (MRF-FISP) with a single-band RF excitation. The phantom results showed that the simultaneous multislice imaging MRF-FISP method quantified the relaxation properties accurately compared to the gold-standard spin echo methods. T 1 and T 2 values of in vivo brain from the proposed method also matched the results from the normal MRF-FISP acquisition. T 1 and T 2 values can be quantified at a multiband acceleration factor of two using our proposed acquisition even in a single-channel receive coil. Further acceleration could be achieved by combining this method with parallel imaging or iterative reconstruction. Magn Reson Med 78:1870-1876, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

A Unified Approach to Diffusion Direction Sensitive Slice Registration and 3-D DTI Reconstruction From Moving Fetal Brain Anatomy

DEFF Research Database (Denmark)

Hansen, Mads Fogtmann; Seshamani, Sharmishtaa; Kroenke, Christopher

2014-01-01

to the underlying anatomy. Previous image registration techniques have been described to estimate the between slice fetal head motion, allowing the reconstruction of 3D a diffusion estimate on a regular grid using interpolation. We propose Approach to Unified Diffusion Sensitive Slice Alignment and Reconstruction...... (AUDiSSAR) that explicitly formulates a process for diffusion direction sensitive DW-slice-to-DTI-volume alignment. This also incorporates image resolution modeling to iteratively deconvolve the effects of the imaging point spread function using the multiple views provided by thick slices acquired...

The differential effects of acute right- vs. left-sided vestibular failure on brain metabolism.

Science.gov (United States)

Becker-Bense, Sandra; Dieterich, Marianne; Buchholz, Hans-Georg; Bartenstein, Peter; Schreckenberger, Mathias; Brandt, Thomas

2014-07-01

The human vestibular system is represented in the brain bilaterally, but it has functional asymmetries, i.e., a dominance of ipsilateral pathways and of the right hemisphere in right-handers. To determine if acute right- or left-sided unilateral vestibular neuritis (VN) is associated with differential patterns of brain metabolism in areas representing the vestibular network and the visual-vestibular interaction, patients with acute VN (right n = 9; left n = 13) underwent resting state (18)F-FDG PET once in the acute phase and once 3 months later after central vestibular compensation. The contrast acute vs. chronic phase showed signal differences in contralateral vestibular areas and the inverse contrast in visual cortex areas, both more pronounced in VN right. In VN left additional regions were found in the cerebellar hemispheres and vermis bilaterally, accentuated in severe cases. In general, signal changes appeared more pronounced in patients with more severe vestibular deficits. Acute phase PET data of patients compared to that of age-matched healthy controls disclosed similarities to these patterns, thus permitting the interpretation that the signal changes in vestibular temporo-parietal areas reflect signal increases, and in visual areas, signal decreases. These data imply that brain activity in the acute phase of right- and left-sided VN exhibits different compensatory patterns, i.e., the dominant ascending input is shifted from the ipsilateral to the contralateral pathways, presumably due to the missing ipsilateral vestibular input. The visual-vestibular interaction patterns were preserved, but were of different prominence in each hemisphere and more pronounced in patients with right-sided failure and more severe vestibular deficits.

Brain CT scan in acute carbon monoxide poisoning

International Nuclear Information System (INIS)

We, En-Huei

1986-01-01

The brain CT findings in 19 patients with acute carbon monoxide poisoning was analysed and the emphasis was placed on the relationship between CT findings and prognosis. Five had a normal manifestation in CT ; eight had the findings of ovoid or patchy low density area in globus pallidus, bilateral or unlateral, during the second day to fifth week after poisoning, and the low density areas were decreasing and blurring in edge in follow up and at last disappeared during 3 - 14 weeks in three cases of them ; nine showed the appearance of diffuse low density of white matter and of globus pallidus in some of them ; two had an appearance of brain atrophy. The pathology of CT findings mentioned above may be brain edema, necrosis, malacia and degeneration in gray matter and globus pallidus. The result suggested the cases with normal CT manifestation, cerebral edema and decreasing and disappearing low density area had a good prognosis, in contrary, the cases with persistant low density in globus pallidus had a poorer prognosis. (author)

Novel active contour model based on multi-variate local Gaussian distribution for local segmentation of MR brain images

Science.gov (United States)

Zheng, Qiang; Li, Honglun; Fan, Baode; Wu, Shuanhu; Xu, Jindong

2017-12-01

Active contour model (ACM) has been one of the most widely utilized methods in magnetic resonance (MR) brain image segmentation because of its ability of capturing topology changes. However, most of the existing ACMs only consider single-slice information in MR brain image data, i.e., the information used in ACMs based segmentation method is extracted only from one slice of MR brain image, which cannot take full advantage of the adjacent slice images' information, and cannot satisfy the local segmentation of MR brain images. In this paper, a novel ACM is proposed to solve the problem discussed above, which is based on multi-variate local Gaussian distribution and combines the adjacent slice images' information in MR brain image data to satisfy segmentation. The segmentation is finally achieved through maximizing the likelihood estimation. Experiments demonstrate the advantages of the proposed ACM over the single-slice ACM in local segmentation of MR brain image series.

Ripple artifact reduction using slice overlap in slice encoding for metal artifact correction.

Science.gov (United States)

den Harder, J Chiel; van Yperen, Gert H; Blume, Ulrike A; Bos, Clemens

2015-01-01

Multispectral imaging (MSI) significantly reduces metal artifacts. Yet, especially in techniques that use gradient selection, such as slice encoding for metal artifact correction (SEMAC), a residual ripple artifact may be prominent. Here, an analysis is presented of the ripple artifact and of slice overlap as an approach to reduce the artifact. The ripple artifact was analyzed theoretically to clarify its cause. Slice overlap, conceptually similar to spectral bin overlap in multi-acquisition with variable resonances image combination (MAVRIC), was achieved by reducing the selection gradient and, thus, increasing the slice profile width. Time domain simulations and phantom experiments were performed to validate the analyses and proposed solution. Discontinuities between slices are aggravated by signal displacement in the frequency encoding direction in areas with deviating B0. Specifically, it was demonstrated that ripple artifacts appear only where B0 varies both in-plane and through-plane. Simulations and phantom studies of metal implants confirmed the efficacy of slice overlap to reduce the artifact. The ripple artifact is an important limitation of gradient selection based MSI techniques, and can be understood using the presented simulations. At a scan-time penalty, slice overlap effectively addressed the artifact, thereby improving image quality near metal implants. © 2014 Wiley Periodicals, Inc.

Thrombolysis in Stroke within 30 Minutes: Results of the Acute Brain Care Intervention Study

NARCIS (Netherlands)

Zinkstok, Sanne M.; Beenen, Ludo F.; Luitse, Jan S.; Majoie, Charles B.; Nederkoorn, Paul J.; Roos, Yvo B.

2016-01-01

Time is brain: benefits of intravenous thrombolysis (IVT) in ischemic stroke last for 4.5 hours but rapidly decrease as time progresses following symptom onset. The goal of the Acute Brain Care (ABC) intervention study was to reduce the door-to-needle time (DNT) to ≤30 minutes by optimizing

Inhibitory effect of magnesium sulfate on reaction of lipid hyperoxidation after radiation-induced acute brain injuries

International Nuclear Information System (INIS)

Wang Lili; Zhou Juying; Yu Zhiying; Qin Songbing; Xu Xiaoting; Li Li; Tu Yu

2007-01-01

Objective: To explore the protection of magnesium sulfate (MgSO 4 ) on radiation-induced acute brain injuries. Methods: 60 maturity Sprague-Dawley (SD) rats were randomly divided into 3 groups: blank control group, experimental control group and experimental-therapeutic group. The whole brain of SD rats of experimental control group and experimental-therapeutic group was irradiated to a dose of 20 Gy using 6 MeV electron. MgSO 4 was injected intraperitoneally into the rats of experimental-therapeutic group before and after irradiation for five times. At different time points ranging from the 1 d, 7 d, 14 d, 30 d after irradiation, the brain tissue were taken. The xanthine oxidase and colorimetric examination were used to measure the superoxide dismutase (SOD) and malonyldialdehyde (MDA) respectively in the rat brain respectively. Results: Compared with blank control group, the SOD in brain of experimental control group decreased significantly (P 4 used in early stage can inhibit the lipid peroxidation after radiation-induced acute brain injuries and alleviate the damage induced by free radicals to brain tissue. (authors)

Changes in medium radioactivity and composition accompany high-affinity uptake of glutamate and aspartate by mouse brain slices

International Nuclear Information System (INIS)

Latzkovits, L.; Neidle, A.; Lajtha, A.

1984-01-01

In measurements of high affinity transport in tissue slices, the incubation medium is often treated as an ''infinitely large pool''. External substrate concentrations, even at the micromolar level, are assumed to be constant and metabolic interactions between tissue and medium are neglected. In the present report we describe experiments in which glutamic and aspartic acid uptake by mouse brain slices were studied using techniques that could test these assumptions. Cerebral hemispheres were cut into 0.1 mm sections and about 90 mg of tissue incubated in 10 ml of oxygenated medium. After 45 minutes of equilibration, radioactive substrates were added and the concentrations and specific activities of the amino acids and their metabolites in the medium were determined. During the first 10 min following substrate addition, rapid decreases in glutamic and aspartic acid concentrations in the medium were accompanied by large decreases in specific activity caused by the continuous release of these amino acids from the tissue. In addition, extensive conversion of both substrates to glutamine and the preferential accumulation of this metabolite, in the medium, was found. These results demonstrate that metabolism and release occur simultaneously with uptake during transport experiments in vitro and that these processes can take place in specific tissue compartments. It is therefore necessary to measure the tissue and medium concentration levels of amino acids along with their radioactivity in such experiments, since all three processes (transport, metabolism, and compartmentation) are interrelated in the clearance of amino acids from the incubation medium and probably from the extracellular spaces in vivo as well

Quantitative multivoxel H-1 MR spectroscopy of the brain in children with acute liver failure

NARCIS (Netherlands)

Sijens, Paul E.; Alkefaji, Heyder; Lunsing, Roelineke J.; van Spronsen, Francjan J.; Meiners, Linda C.; Oudkerk, Matthijs; Verkade, Henkjan J.

Acute liver failure (ALF)-related encephalopathy was previously characterized by MR spectroscopy of single voxels containing both grey and white matter brain tissue. Quantitative multivoxel MRS was used here to compare grey and white matter brain tissue concentrations of glutamate/glutamine (Glx)

Trafficking of astrocytic vesicles in hippocampal slices

International Nuclear Information System (INIS)

Potokar, Maja; Kreft, Marko; Lee, So-Young; Takano, Hajime; Haydon, Philip G.; Zorec, Robert

2009-01-01

The increasingly appreciated role of astrocytes in neurophysiology dictates a thorough understanding of the mechanisms underlying the communication between astrocytes and neurons. In particular, the uptake and release of signaling substances into/from astrocytes is considered as crucial. The release of different gliotransmitters involves regulated exocytosis, consisting of the fusion between the vesicle and the plasma membranes. After fusion with the plasma membrane vesicles may be retrieved into the cytoplasm and may continue to recycle. To study the mobility implicated in the retrieval of secretory vesicles, these structures have been previously efficiently and specifically labeled in cultured astrocytes, by exposing live cells to primary and secondary antibodies. Since the vesicle labeling and the vesicle mobility properties may be an artifact of cell culture conditions, we here asked whether the retrieving exocytotic vesicles can be labeled in brain tissue slices and whether their mobility differs to that observed in cell cultures. We labeled astrocytic vesicles and recorded their mobility with two-photon microscopy in hippocampal slices from transgenic mice with fluorescently tagged astrocytes (GFP mice) and in wild-type mice with astrocytes labeled by Fluo4 fluorescence indicator. Glutamatergic vesicles and peptidergic granules were labeled by the anti-vesicular glutamate transporter 1 (vGlut1) and anti-atrial natriuretic peptide (ANP) antibodies, respectively. We report that the vesicle mobility parameters (velocity, maximal displacement and track length) recorded in astrocytes from tissue slices are similar to those reported previously in cultured astrocytes.

Early changes of serum insulin-like growth factor-II (IGF-II) levels in patients with acute brain injury

International Nuclear Information System (INIS)

Liu Cegang; Zhang Xinlu; Tao Jin; Xu Anding; Xu Shanshui; Huang Zhenpeng

2003-01-01

Objective: To investigate the early changes and clinical significance of serum Insulin-like growth factor-II (IGF-II) levels in patients with acute brain injury. Methods: Radioimmunoassay was used for measurement of the serum IGF-II concentration in 30 controls and 29 acute brain injury patients before and after treatment (within 1 day, at 3 and 7 days). Results: The serum IGF-II levels in brain injury patients at 1 day, 3 day 7 days after injury were 0.131 ± 0.047 ng/ml, 0.117 ± 0.046 ng/ml and 0.123 ±0.050 ng/ml respectively and were significantly lower than those in controls 0.44 ± 0.014 ng/ml, p<0.01. Differences among the values of the three days were not significant. Conclusion: IGF-II might play important role in the pathophysiological process of early acute brain injury

Metabolism of choline in brain of the aged CBF-1 mouse

International Nuclear Information System (INIS)

Saito, M.; Kindel, G.; Karczmar, A.G.; Rosenberg, A.

1986-01-01

In order to quantify the changes that occur in the cholinergic central nervous system with aging, we have compared acetylcholine (Ach) formation in brain cortex slice preparations from 2-year-old aged CBF-1 mouse brains and compared the findings with those in 2-4-month-old young adult mouse brain slices. Incorporation of exogenous radioactively labelled choline (31 nM [ 3 H] choline) into acetyl choline in incubated brain slices was linear with time for 90 min. Percentage of total choline label distributed into Ach remained constant from 5 min after starting the incubation to 90 min. In contrast, distribution of label into intracellular free choline (Ch) and phosphorylcholine (Pch) changed continuously over this period suggesting that the Ch pool for Ach synthesis in brain cortex is different from that for Pch synthesis. Incorporation of radioactivity into Ach was not influenced by administration of 10 microM eserine, showing that the increment of radioactivity in Ach reflects rate of Ach formation, independently from degradation by acetylcholine esterases. Under our experimental conditions, slices from cortices of aged 24-month-old mouse brain showed a significantly greater (27%) incorporation of radioactivity into intracellular Ach than those from young, 2-4-month-old, brain cortices. Inhibitors of Ach release, 1 mM ATP or GABA, had no effect. Since concentration of radioactive precursor in the incubation medium was very low (31 nM), the Ch pool for Ach synthesis in slices was labelled without measurably changing the size of the endogenous pool. These data suggest a compensatory acceleration of Ach synthesis or else a smaller precursor pool specific for Ach synthesis into which labelled Ch migrated in aged brain

Increased brain natriuretic peptide as a marker for right ventricular dysfunction in acute pulmonary embolism

NARCIS (Netherlands)

Tulevski, I. I.; Hirsch, A.; Sanson, B. J.; Romkes, H.; van der Wall, E. E.; van Veldhuisen, D. J.; Büller, H. R.; Mulder, B. J.

2001-01-01

Right ventricular (RV) function is of major prognostic significance in patients with acute pulmonary embolism (PE). The aim of the present study was to evaluate the role of neurohormone plasma brain natriuretic peptide (BNP) in assessing RV function in patients with acute PE. BNP levels were

Increased brain natriuretic peptide as a marker for right ventricular dysfunction in acute pulmonary embolism

NARCIS (Netherlands)

Tulevski, I.I.; Hirsch, A; Sanson, BJ; Romkes, H; van der Wall, EE; van Veldhuisen, DJ; Buller, HR; Mulder, BJM

Right ventricular (RV) function is of major prognostic significance in patients with acute pulmonary embolism (PE). The aim of the present study was to evaluate the role of neurohormone plasma brain natriuretic peptide (BNP) in assessing RV function in patients with acute PE. BNP levels were

[Possibilities of magnetic-laser therapy in comprehensive treatment of patients with brain concussion in acute period].

Science.gov (United States)

Zubkova, O V; Samosiuk, I Z; Polishchuk, O V; Shul'ga, N M; Samosiuk, N I

2012-01-01

The efficacy of magnetic-laser therapy used according to the method developed by us was studied in patients having the brain concussion (BC) in an acute period. The study was based on the dynamics of values of the evoked vestibular potentials and the disease clinical course. It was shown that following the magnetic-laser therapy in combination with traditional pharmacotherapy in BC acute period, the statistically significant positive changes were registered in the quantitative characteristics of the evoked vestibular brain potentials that correlated with the dynamics of the disease clinical course. The data obtained substantiate the possibility of using the magnetic-laser therapy in patients with a mild craniocereblal injury in an acute period.

Clinical application of magnetic resonance in acute traumatic brain injury

Energy Technology Data Exchange (ETDEWEB)

Morais, Dionei F.; Gaia, Felipe F.P. [Hospital de Base de Sao Jose do Rio Preto, SP (Brazil). Servico de Neurocirurgia]. E-mail: centro@cerebroecoluna.com.br; Spotti, Antonio R.; Tognola, Waldir A. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Ciencias Neurologicas; Andrade, Almir F. [Universidade de Sao Paulo (USP), SP (Brazil). Hospital das Clinicas. Dept. de Neurocirurgia da Emergencia

2008-07-01

Purpose: To evaluate the clinical applications of magnetic resonance imaging (MRI) in patients with acute traumatic brain injury (TBI): to identify the type, quantity, severity; and improvement clinical-radiological correlation. Method: Assessment of 55 patients who were imaged using CT and MRI, 34 (61.8%) males and 21 (38.2%) females, with acute (0 to 5 days) and closed TBI. Results: Statistical significant differences (McNemar test): occurred fractures were detected by CT in 29.1% and by MRI in 3.6% of the patients; subdural hematoma by CT in 10.9% and MRI in 36.4 %; diffuse axonal injury (DAI) by CT in 1.8% and MRI in 50.9%; cortical contusions by CT in 9.1% and MRI in 41.8%; subarachnoid hemorrhage by CT in 18.2% and MRI in 41.8%. Conclusion: MRI was superior to the CT in the identification of DAI, subarachnoid hemorrhage, cortical contusions, and acute subdural hematoma; however it was inferior in diagnosing fractures. The detection of DAI was associated with the severity of acute TBI. (author)

Clinical application of magnetic resonance in acute traumatic brain injury

International Nuclear Information System (INIS)

Morais, Dionei F.; Gaia, Felipe F.P.; Spotti, Antonio R.; Tognola, Waldir A.; Andrade, Almir F.

2008-01-01

Purpose: To evaluate the clinical applications of magnetic resonance imaging (MRI) in patients with acute traumatic brain injury (TBI): to identify the type, quantity, severity; and improvement clinical-radiological correlation. Method: Assessment of 55 patients who were imaged using CT and MRI, 34 (61.8%) males and 21 (38.2%) females, with acute (0 to 5 days) and closed TBI. Results: Statistical significant differences (McNemar test): occurred fractures were detected by CT in 29.1% and by MRI in 3.6% of the patients; subdural hematoma by CT in 10.9% and MRI in 36.4 %; diffuse axonal injury (DAI) by CT in 1.8% and MRI in 50.9%; cortical contusions by CT in 9.1% and MRI in 41.8%; subarachnoid hemorrhage by CT in 18.2% and MRI in 41.8%. Conclusion: MRI was superior to the CT in the identification of DAI, subarachnoid hemorrhage, cortical contusions, and acute subdural hematoma; however it was inferior in diagnosing fractures. The detection of DAI was associated with the severity of acute TBI. (author)

The brain is a target organ after acute exposure to depleted uranium.

Science.gov (United States)

Lestaevel, P; Houpert, P; Bussy, C; Dhieux, B; Gourmelon, P; Paquet, F

2005-09-01

The health effects of depleted uranium (DU) are mainly caused by its chemical toxicity. Although the kidneys are the main target organs for uranium toxicity, uranium can also reach the brain. In this paper, the central effects of acute exposure to DU were studied in relation to health parameters and the sleep-wake cycle of adult rats. Animals were injected intraperitoneally with 144+/-10 microg DU kg-1 as nitrate. Three days after injection, the amounts of uranium in the kidneys represented 2.6 microg of DU g-1 of tissue, considered as a sub-nephrotoxic dosage. The central effect of uranium could be seen through a decrease in food intake as early as the first day after exposure and shorter paradoxical sleep 3 days after acute DU exposure (-18% of controls). With a lower dosage of DU (70+/-8 microg DU kg-1), no significant effect was observed on the sleep-wake cycle. The present study intends to illustrate the fact that the brain is a target organ, as are the kidneys, after acute exposure to a moderate dosage of DU. The mechanisms by which uranium causes these early neurophysiological perturbations shall be discussed.

Portable Device Slices Thermoplastic Prepregs

Science.gov (United States)

Taylor, Beverly A.; Boston, Morton W.; Wilson, Maywood L.

1993-01-01

Prepreg slitter designed to slit various widths rapidly by use of slicing bar holding several blades, each capable of slicing strip of preset width in single pass. Produces material evenly sliced and does not contain jagged edges. Used for various applications in such batch processes involving composite materials as press molding and autoclaving, and in such continuous processes as pultrusion. Useful to all manufacturers of thermoplastic composites, and in slicing B-staged thermoset composites.

Reversible brain damage following acute organic solvents' poisoning determined by magnetic resonance

Directory of Open Access Journals (Sweden)

Dujmović Irena

2005-01-01

Full Text Available Introduction. Acute exposure to the effects of volatile solvents is characterized by the abrupt onset of symptoms and signs of poisoning, and relatively fast recovery in the majority of cases. Case report. We report a 24-year-old patient with an acute, accidental poisoning with a mixture of volatile organic solvents (most probably toluene, styrene and xylene, which led to the development of upward gaze paresis, diplopia, hemiparesis, ataxic gate, and the late onset truncal ataxia episodes. After 6 weeks, he recovered completely, while his extensive brain MRI lesions in the caudate nuclei, laterobasal putaminal regions, bilateral anterior insular cortex, central midbrain tegmental area withdrew completely after 4 months. Conclusion. Acute toxic encephalopathy should be a part of the differential diagnosis in any patient with acute neurobehavioral and neurological deficit.

Removal of area CA3 from hippocampal slices induces postsynaptic plasticity at Schaffer collateral synapses that normalizes CA1 pyramidal cell discharge.

Science.gov (United States)

Dumas, Theodore C; Uttaro, Michael R; Barriga, Carolina; Brinkley, Tiffany; Halavi, Maryam; Wright, Susan N; Ferrante, Michele; Evans, Rebekah C; Hawes, Sarah L; Sanders, Erin M

2018-05-05

Neural networks that undergo acute insults display remarkable reorganization. This injury related plasticity is thought to permit recovery of function in the face of damage that cannot be reversed. Previously, an increase in the transmission strength at Schaffer collateral to CA1 pyramidal cell synapses was observed after long-term activity reduction in organotypic hippocampal slices. Here we report that, following acute preparation of adult rat hippocampal slices and surgical removal of area CA3, input to area CA1 was reduced and Schaffer collateral synapses underwent functional strengthening. This increase in synaptic strength was limited to Schaffer collateral inputs (no alteration to temporoammonic synapses) and acted to normalize postsynaptic discharge, supporting a homeostatic or compensatory response. Short-term plasticity was not altered, but an increase in immunohistochemical labeling of GluA1 subunits was observed in the stratum radiatum (but not stratum moleculare), suggesting increased numbers of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors and a postsynaptic locus of expression. Combined, these data support the idea that, in response to the reduction in presynaptic activity caused by removal of area CA3, Schaffer collateral synapses undergo a relatively rapid increase in functional efficacy likely supported by insertion of more AMPARs, which maintains postsynaptic excitability in CA1 pyramidal neurons. This novel fast compensatory plasticity exhibits properties that would allow it to maintain optimal network activity levels in the hippocampus, a brain structure lauded for its ongoing experience-dependent malleability. Copyright © 2018 Elsevier B.V. All rights reserved.

Hyperbaric oxygen therapy ameliorates acute brain injury after porcine intracerebral hemorrhage at high altitude.

Science.gov (United States)

Zhu, Hai-tao; Bian, Chen; Yuan, Ji-chao; Liao, Xiao-jun; Liu, Wei; Zhu, Gang; Feng, Hua; Lin, Jiang-kai

2015-06-15

Intracerebral hemorrhage (ICH) at high altitude is not well understood to date. This study investigates the effects of high altitude on ICH, and examines the acute neuroprotection of hyperbaric oxygen (HBO) therapy against high-altitude ICH. Minipigs were placed in a hypobaric chamber for 72 h before the operation. ICH was induced by an infusion of autologous arterial blood (3 ml) into the right basal ganglia. Animals in the high-altitude ICH group received HBO therapy (2.5 ATA for 60 min) 30 min after ICH. Blood gas, blood glucose and brain tissue oxygen partial pressure (PbtO2) were monitored continuously for animals from all groups, as were microdialysis products including glucose, lactate, pyruvate and glutamate in perihematomal tissue from 3 to 12 h post-ICH. High-altitude ICH animals showed significantly lower PbtO2, higher lactate/pyruvate ratio (LPR) and glutamate levels than low-altitude ICH animals. More severe neurological deficits, brain edema and neuronal damage were also observed in high-altitude ICH. After HBO therapy, PbtO2 was significantly increased and LPR and glutamate levels were significantly decreased. Brain edema, neurological deficits and neuronal damage were also ameliorated. The data suggested a more serious disturbance of tissue oxygenation and cerebral metabolism in the acute stage after ICH at high altitude. Early HBO treatment reduced acute brain injury, perhaps through a mechanism involving the amelioration of the derangement of cerebral oxygenation and metabolism following high-altitude ICH.

Alterations in the properties of neonatal thalamocortical synapses with time in in vitro slices.

Directory of Open Access Journals (Sweden)

Liliana L Luz

Full Text Available New synapses are constantly being generated and lost in the living brain with only a subset of these being stabilized to form an enduring component of neuronal circuitry. The properties of synaptic transmission have primarily been established in a variety of in vitro neuronal preparations. It is not clear, however, if newly-formed and persistent synapses contribute to the results of these studies consistently throughout the lifespan of these preparations. In neonatal somatosensory, barrel, cortex we have previously hypothesized that a population of thalamocortical synapses displaying unusually slow kinetics represent newly-formed, default-transient synapses. This clear phenotype would provide an ideal tool to investigate if such newly formed synapses consistently contribute to synaptic transmission throughout a normal experimental protocol. We show that the proportion of synapses recorded in vitro displaying slow kinetics decreases with time after brain slice preparation. However, slow synapses persist in vitro in the presence of either minocycline, an inhibitor of microglia-mediated synapse elimination, or the TrkB agonist 7,8-dihydroxyflavone a promoter of synapse formation. These findings show that the observed properties of synaptic transmission may systematically change with time in vitro in a standard brain slice preparation.

Diffusion Tensor Tractography Imaging in a Case of Acute Brain Stem Infarct

Directory of Open Access Journals (Sweden)

Nilgül Yardımcı

2009-03-01

Full Text Available Diffusion tensor tractography enables graphical reconstruction of the white matter pathways in the brain and quantitative study of white matter integrity. With this method virtual dissection of the living human brain can be performed. This technique has many potential clinical applications in neurological disorders, including the investigation of stroke. We present tractography findings of a patient that had an acute ischemic infarct in the brain stem. We aimed to report the disintegration of the white matter tracts at the infarct location in vivo, as well as the associated clinical symptoms. The current use of tractography in neurological disorders shows that it has the potential to improve our understanding of the damage and recovery process in diseases of the brain and spinal cord. From a clinical point of view tractography might be used to test new hypotheses, and to provide important new insights into the organization of the brain and the effects of brain disorders

The role of glutamine transport in metabolism in the brain cortical tissue slice

International Nuclear Information System (INIS)

Hare, N.; Bubb, W.A.; Rae, C.; Broeer, S.

2001-01-01

The widely accepted 'glutamate/glutamine cycle' holds that glutamate released as a neurotransmitter in the brain is taken up by surrounding astrocytes, converted to neuro-inactive glutamine and transported back to neurons for reconversion to glutamate. Little, however, is known about the role of glutamine transport in this process. The situation is complicated by the fact that glutamine is transported by a variety of general amino-acid transporters of low specificity. The role of these transporters in flux of glutamine through the glutamate/glutamine cycle was investigated by 13 C NMR monitoring of the flux of C from [3- 13 C]L-lactate in guinea pig cortical tissue slices in the presence of competitive inhibitors of the A-type(α-(methylamino)isobutyrate; MeAIB) and N-type (histidine) transporters. The presence of each inhibitor (10 mM) produced no significant decrease in total metabolite pool size but resulted in a significant decrease in flux of [ 13 C] into the neurotransmitters glutamate and GABA and also into glutamine and alanine. The factional enrichment of glutamate and GABA was also significantly lower. By contrast there was no effect on the amount of [ 13 C] incorporated into aspartate isotopomers which may represent a predominantly astrocyte-labelled pool. These results are consistent with involvement of glutamine transporters in the recycling of synaptic glutamate by demonstrating partial blockage of incorporation of [ 13 C] label into neuronal metabolites

Electrical and chemical transmission between striatal GABAergic output neurones in rat brain slices

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Venance, Laurent; Glowinski, Jacques; Giaume, Christian

2004-01-01

Basal ganglia are interconnected subcortical nuclei, connected to the thalamus and all cortical areas involved in sensory motor control, limbic functions and cognition. The striatal output neurones (SONs), the major striatal population, are believed to act as detectors and integrators of distributed patterns of cerebral cortex inputs. Despite the key role of SONs in cortico-striatal information processing, little is known about their local interactions. Here, we report the existence and characterization of electrical and GABAergic transmission between SONs in rat brain slices. Tracer coupling (biocytin) incidence was high during the first two postnatal weeks and then decreased (postnatal days (P) 5–25, 60%; P25–30, 29%; n = 61). Electrical coupling was observed between 27% of SON pairs (coupling coefficient: 3.1 ± 0.3%, n = 89 at P15) and as shown by single-cell RT-PCR, several connexin (Cx) mRNAs were found to be expressed (Cx31.1, Cx32, Cx36 and Cx47). GABAergic synaptic transmission (abolished by bicuculline, a GABAA receptor antagonist) observed in 19% of SON pairs (n = 62) was reliable (mean failure rate of 6 ± 3%), precise (variation coefficient of latency, 0.06), strong (IPSC amplitudes of 38 ± 12 pA) and unidirectional. Interestingly, electrical and chemical transmission were mutually exclusive. These results suggest that preferential networks of electrically and chemically connected SONs, might be involved in the channelling of cortico-basal ganglia information processing. PMID:15235091

Psychological Characteristics in Acute Mild Traumatic Brain Injury: An MMPI-2 Study.

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Gass, Carlton S; Rogers, David; Kinne, Erica

2017-01-01

The psychological characteristics of acute traumatic brain injury (TBI) have received limited research focus, despite empirical evidence of their relevance for subsequent psychological adjustment and early therapeutic intervention. This study addressed a wide range of psychological features in 47 individuals who were hospitalized as a result of acute mild TBI (mTBI). Participants were screened from amongst consecutive TBI admissions for moderate to severe brain injury, and for pre-injury neurological, psychiatric, or substance abuse histories. Clinical and content scale scores on the MMPI-2 were explored in relation to patient gender, age, level of education, and extent of cognitive complaints. The results revealed diverse psychosocial problem areas across the sample, the most common of which were somatic and cognitive complaints, compromised insight, and a naively optimistic self-perception. The mediating roles of injury severity and demographic variables are discussed. Clinical implications and specific recommendations are presented.

Cognitive benefit and cost of acute stress is differentially modulated by individual brain state.

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Kohn, Nils; Hermans, Erno J; Fernández, Guillén

2017-07-01

Acute stress is associated with beneficial as well as detrimental effects on cognition in different individuals. However, it is not yet known how stress can have such opposing effects. Stroop-like tasks typically show this dissociation: stress diminishes speed, but improves accuracy. We investigated accuracy and speed during a stroop-like task of 120 healthy male subjects after an experimental stress induction or control condition in a randomized, counter-balanced cross-over design; we assessed brain-behavior associations and determined the influence of individual brain connectivity patterns on these associations, which may moderate the effect and help identify stress resilience factors. In the mean, stress was associated to increase in accuracy, but decrease in speed. Accuracy was associated to brain activation in a distributed set of brain regions overlapping with the executive control network (ECN) and speed to temporo-parietal activation. In line with a stress-related large-scale network reconfiguration, individuals showing an upregulation of the salience and down-regulation of the executive-control network under stress displayed increased speed, but decreased performance. In contrast, individuals who upregulate their ECN under stress show improved performance. Our results indicate that the individual large-scale brain network balance under acute stress moderates cognitive consequences of threat. © The Author (2017). Published by Oxford University Press.

[Expression of aquaporin-4 during brain edema in rats with thioacetamide-induced acute encephalopathy].

Science.gov (United States)

Wang, Li-Qing; Zhu, Sheng-Mei; Zhou, Heng-Jun; Pan, Cai-Fei

2011-09-27

To investigate the expression of aquaporin-4 (AQP4) during brain edema in rats with thioacetamide-induced acute liver failure and encephalopathy. The rat model of acute hepatic failure and encephalopathy was induced by intraperitoneal injection of thioacetamide (TAA) at a 24-hour interval for 2 consecutive days. Thirty-two SD rats were randomly divided into the model group (n = 24) and the control group (normal saline, n = 8). And then the model group was further divided into 3 subgroups by the timepoint of decapitation: 24 h (n = 8), 48 h (n = 8) and 60 h (n = 8). Then we observed their clinical symptoms and stages of HE, indices of liver function and ammonia, liver histology and brain water content. The expression of AQP4 protein in brain tissues was measured with Western blot and the expression of AQP4mRNA with RT-PCR (reverse transcription-polymerase chain reaction). Typical clinical manifestations of hepatic encephalopathy occurred in all TAA-administrated rats. The model rats showed the higher indices of ALT (alanine aminotransferase), AST (aspartate aminotransferase), TBIL (total bilirubin) and ammonia than the control rats (P liver failure and encephalopathy plays a significant role during brain edema. AQP4 is one of the molecular mechanisms for the occurrence of brain edema in hepatic encephalopathy.

Fresh Slice Self-Seeding and Fresh Slice Harmonic Lasing at LCLS

Energy Technology Data Exchange (ETDEWEB)

Amann, J.W. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

2018-04-01

We present results from the successful demonstration of fresh slice self-seeding at the Linac Coherent Light Source (LCLS).* The performance is compared with SASE and regular self-seeding at photon energy of 5.5 keV, resulting in a relative average brightness increase of a factor of 12 and a factor of 2 respectively. Following this proof-of-principle we discuss the forthcoming plans to use the same technique** for fresh slice harmonic lasing in an upcoming experiment. The demonstration of fresh slice harmonic lasing provides an attractive solution for future XFELs aiming to achieve high efficiency, high brightness X-ray pulses at high photon energies (>12 keV).***

Flat slices in Minkowski space

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Murchadha, Niall Ó.; Xie, Naqing

2015-03-01

Minkowski space, flat spacetime, with a distance measure in natural units of d{{s}2}=-d{{t}2}+d{{x}2}+d{{y}2}+d{{z}2}, or equivalently, with spacetime metric diag(-1, +1, +1, +1), is recognized as a fundamental arena for physics. The Poincaré group, the set of all rigid spacetime rotations and translations, is the symmetry group of Minkowski space. The action of this group preserves the form of the spacetime metric. Each t = constant slice of each preferred coordinate system is flat. We show that there are also nontrivial non-singular representations of Minkowski space with complete flat slices. If the embedding of the flat slices decays appropriately at infinity, the only flat slices are the standard ones. However, if we remove the decay condition, we find non-trivial flat slices with non-vanishing extrinsic curvature. We write out explicitly the coordinate transformation to a frame with such slices.

Investigating structure and function in the healthy human brain: validity of acute versus chronic lesion-symptom mapping.

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Karnath, Hans-Otto; Rennig, Johannes

2017-07-01

Modern voxel-based lesion-symptom mapping (VLSM) analyses techniques provide powerful tools to examine the relationship between structure and function of the healthy human brain. However, there is still uncertainty on the type of and the appropriate time point of imaging and of behavioral testing for such analyses. Here we tested the validity of the three most common combinations of structural imaging data and behavioral scores used in VLSM analyses. Given the established knowledge about the neural substrate of the primary motor system in humans, we asked the mundane question of where the motor system is represented in the normal human brain, analyzing individual arm motor function of 60 unselected stroke patients. Only the combination of acute behavioral scores and acute structural imaging precisely identified the principal brain area for the emergence of hemiparesis after stroke, i.e., the corticospinal tract (CST). In contrast, VLSM analyses based on chronic behavior-in combination with either chronic or acute imaging-required the exclusion of patients who had recovered from an initial paresis to reveal valid anatomical results. Thus, if the primary research aim of a VLSM lesion analysis is to uncover the neural substrates of a certain function in the healthy human brain and if no longitudinal designs with repeated evaluations are planned, the combination of acute imaging and behavior represents the ideal dataset.

Effects of Temperature and Slice Thickness on Drying Kinetics of Pumpkin Slices

OpenAIRE

Kongdej LIMPAIBOON

2011-01-01

Dried pumpkin slice is an alternative crisp food product. In this study, the effects of temperature and slice thickness on the drying characteristics of pumpkin were studied in a lab-scale tray dryer, using hot air temperatures of 55, 60 and 65 °C and 2, 3 and 4 mm slice thickness at a constant air velocity of 1.5 m/s. The initial moisture content of the pumpkin samples was 900.5 % (wb). The drying process was carried out until the final moisture content of product was 100.5 % (wb). The resul...

Workbench surface editor of brain cortical surface

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Dow, Douglas E.; Nowinski, Wieslaw L.; Serra, Luis

1996-04-01

We have developed a 3D reach-in tool to manually reconstruct 3D cortical surface patches from 2D brain atlas images. The first application of our cortex editor is building 3D functional maps, specifically Brodmann's areas. This tool may also be useful in clinical practice to adjust incorrectly mapped atlas regions due to the deforming effect of lesions. The cortex editor allows a domain expert to control the correlation of control points across slices. Correct correlation has been difficult for 3D reconstruction algorithms because the atlas slices are far apart and because of the complex topology of the cortex which differs so much from slice to slice. Also, higher precision of the resulting surfaces is demanded since these define 3D brain atlas features upon which future stereotactic surgery may be based. The cortex editor described in this paper provides a tool suitable for a domain expert to use in defining the 3D surface of a Brodmann's area.

Attenuation of hypoxic current by intracellular applications of ATP regenerating agents in hippocampal CA1 neurons of rat brain slices.

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Chung, I; Zhang, Y; Eubanks, J H; Zhang, L

1998-10-01

Hypoxia-induced outward currents (hyperpolarization) were examined in hippocampal CA1 neurons of rat brain slices, using the whole-cell recording technique. Hypoxic episodes were induced by perfusing slices with an artificial cerebrospinal fluid aerated with 5% CO2/95% N2 rather than 5% CO2/95% O2, for about 3 min. The hypoxic current was consistently and reproducibly induced in CA1 neurons dialysed with an ATP-free patch pipette solution. This current manifested as an outward shift in the holding current in association with increased conductance, and it reversed at -78 +/- 2.5 mV, with a linear I-V relation in the range of -100 to -40 mV. To provide extra energy resources to individual neurons recorded, agents were added to the patch pipette solution, including MgATP alone, MgATP + phosphocreatine + creatine kinase, or MgATP + creatine. In CA1 neurons dialysed with patch solutions including these agents, hypoxia produced small outward currents in comparison with those observed in CA1 neurons dialysed with the ATP-free solution. Among the above agents examined, whole-cell dialysis with MgATP + creatine was the most effective at decreasing the hypoxic outward currents. We suggest that the hypoxic hyperpolarization is closely related to energy metabolism in individual CA1 neurons, and that the energy supply provided by phosphocreatine metabolism may play a critical role during transient metabolic stress.

Rapid whole-brain resting-state fMRI at 3 T: Efficiency-optimized three-dimensional EPI versus repetition time-matched simultaneous-multi-slice EPI.

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Stirnberg, Rüdiger; Huijbers, Willem; Brenner, Daniel; Poser, Benedikt A; Breteler, Monique; Stöcker, Tony

2017-12-01

State-of-the-art simultaneous-multi-slice (SMS-)EPI and 3D-EPI share several properties that benefit functional MRI acquisition. Both sequences employ equivalent parallel imaging undersampling with controlled aliasing to achieve high temporal sampling rates. As a volumetric imaging sequence, 3D-EPI offers additional means of acceleration complementary to 2D-CAIPIRINHA sampling, such as fast water excitation and elliptical sampling. We performed an application-oriented comparison between a tailored, six-fold CAIPIRINHA-accelerated 3D-EPI protocol at 530 ms temporal and 2.4 mm isotropic spatial resolution and an SMS-EPI protocol with identical spatial and temporal resolution for whole-brain resting-state fMRI at 3 T. The latter required eight-fold slice acceleration to compensate for the lack of elliptical sampling and fast water excitation. Both sequences used vendor-supplied on-line image reconstruction. We acquired test/retest resting-state fMRI scans in ten volunteers, with simultaneous acquisition of cardiac and respiration data, subsequently used for optional physiological noise removal (nuisance regression). We found that the 3D-EPI protocol has significantly increased temporal signal-to-noise ratio throughout the brain as compared to the SMS-EPI protocol, especially when employing motion and nuisance regression. Both sequence types reliably identified known functional networks with stronger functional connectivity values for the 3D-EPI protocol. We conclude that the more time-efficient 3D-EPI primarily benefits from reduced parallel imaging noise due to a higher, actual k-space sampling density compared to SMS-EPI. The resultant BOLD sensitivity increase makes 3D-EPI a valuable alternative to SMS-EPI for whole-brain fMRI at 3 T, with voxel sizes well below 3 mm isotropic and sampling rates high enough to separate dominant cardiac signals from BOLD signals in the frequency domain. Copyright © 2017 Elsevier Inc. All rights reserved.

Experimental demonstration of spectrum-sliced elastic optical path network (SLICE).

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Kozicki, Bartłomiej; Takara, Hidehiko; Tsukishima, Yukio; Yoshimatsu, Toshihide; Yonenaga, Kazushige; Jinno, Masahiko

2010-10-11

We describe experimental demonstration of spectrum-sliced elastic optical path network (SLICE) architecture. We employ optical orthogonal frequency-division multiplexing (OFDM) modulation format and bandwidth-variable optical cross-connects (OXC) to generate, transmit and receive optical paths with bandwidths of up to 1 Tb/s. We experimentally demonstrate elastic optical path setup and spectrally-efficient transmission of multiple channels with bit rates ranging from 40 to 140 Gb/s between six nodes of a mesh network. We show dynamic bandwidth scalability for optical paths with bit rates of 40 to 440 Gb/s. Moreover, we demonstrate multihop transmission of a 1 Tb/s optical path over 400 km of standard single-mode fiber (SMF). Finally, we investigate the filtering properties and the required guard band width for spectrally-efficient allocation of optical paths in SLICE.

Trimethyltin (TMT) neurotoxicity in organotypic rat hippocampal slice cultures

DEFF Research Database (Denmark)

Noraberg, J; Gramsbergen, J B; Fonnum, F

1998-01-01

) propidium iodide (PI) uptake, (b) lactate dehydrogenase (LDH) efflux into the culture medium, (c) cellular cobalt uptake as an index of calcium influx, (d) ordinary Nissl cell staining, and (e) immunohistochemical staining for microtubule-associated protein 2 (MAP-2). Cellular degeneration as assessed...... to in vivo cell stain observations of rats acutely exposed to TMT. The mean PI uptake of the cultures and the LDH efflux into the medium were highly correlated. The combined results obtained by the different markers indicate that the hippocampal slice culture method is a feasible model for further studies...

The effect of head size/shape, miscentering, and bowtie filter on peak patient tissue doses from modern brain perfusion 256-slice CT: How can we minimize the risk for deterministic effects?

International Nuclear Information System (INIS)

Perisinakis, Kostas; Seimenis, Ioannis; Tzedakis, Antonis; Papadakis, Antonios E.; Damilakis, John

2013-01-01

Purpose: To determine patient-specific absorbed peak doses to skin, eye lens, brain parenchyma, and cranial red bone marrow (RBM) of adult individuals subjected to low-dose brain perfusion CT studies on a 256-slice CT scanner, and investigate the effect of patient head size/shape, head position during the examination and bowtie filter used on peak tissue doses. Methods: The peak doses to eye lens, skin, brain, and RBM were measured in 106 individual-specific adult head phantoms subjected to the standard low-dose brain perfusion CT on a 256-slice CT scanner using a novel Monte Carlo simulation software dedicated for patient CT dosimetry. Peak tissue doses were compared to corresponding thresholds for induction of cataract, erythema, cerebrovascular disease, and depression of hematopoiesis, respectively. The effects of patient head size/shape, head position during acquisition and bowtie filter used on resulting peak patient tissue doses were investigated. The effect of eye-lens position in the scanned head region was also investigated. The effect of miscentering and use of narrow bowtie filter on image quality was assessed. Results: The mean peak doses to eye lens, skin, brain, and RBM were found to be 124, 120, 95, and 163 mGy, respectively. The effect of patient head size and shape on peak tissue doses was found to be minimal since maximum differences were less than 7%. Patient head miscentering and bowtie filter selection were found to have a considerable effect on peak tissue doses. The peak eye-lens dose saving achieved by elevating head by 4 cm with respect to isocenter and using a narrow wedge filter was found to approach 50%. When the eye lies outside of the primarily irradiated head region, the dose to eye lens was found to drop to less than 20% of the corresponding dose measured when the eye lens was located in the middle of the x-ray beam. Positioning head phantom off-isocenter by 4 cm and employing a narrow wedge filter results in a moderate reduction of

Brain perfusion CT in acute stroke: current status

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Koenig, Matthias E-mail: matthias.koenig@ruhr-uni-bochum.de

2003-03-01

Dynamic perfusion CT has become a widely accepted imaging modality for the diagnostic workup of acute stroke patients. Although compared with standard spiral CT the use of multislice CT has broadened the range from which perfusion data may be derived in a single scan run. The advent of multidetector row technology has not really overcome the limited 3D capability of this technique. Multidetector CT angiography (CTA) of the cerebral arteries may in part compensate for this by providing additional information about the cerebrovascular status. This article describes the basics of cerebral contrast bolus scanning with a special focus on optimization of contrast/noise in order to ensure high quality perfusion maps. Dedicated scan protocols including low tube voltage (80 kV) as well as the use of highly concentrated contrast media are amongst the requirements to achieve optimum contrast signal from the short bolus passage through the brain. Advanced pre and postprocessing algorithms may help reduce the noise level, which may become critical in unconscious stroke victims. Two theoretical concepts have been described for the calculation of tissue perfusion from contrast bolus studies, both of which can be equally employed for brain perfusion imaging. For each perfusion model there are some profound limitations regarding the validity of perfusion values derived from ischemic brain areas. This makes the use of absolute quantitative cerebral blood flow (CBF) values for the discrimination of the infarct core from periinfarct ischemia questionable. Multiparameter imaging using maps of CBF, cerebral blood volume (CBV), and a time parameter of the local bolus transit enables analyzing of the cerebral perfusion status in detail. Perfusion CT exceeds plain CT in depicting cerebral hypoperfusion at its earliest stage yielding a sensitivity of about 90% for the detection of embolic and hemodynamic lesions within cerebral hemispheres. Qualitative assessment of brain perfusion can be

Whole-brain perfusion CT using a toggling table technique to predict final infarct volume in acute ischemic stroke.

Science.gov (United States)

Schrader, I; Wilk, D; Jansen, O; Riedel, C

2013-09-01

To evaluate how accurately final infarct volume in acute ischemic stroke can be predicted with perfusion CT (PCT) using a 64-MDCT unit and the toggling table technique. Retrospective analysis of 89 patients with acute ischemic stroke who underwent CCT, CT angiography (CTA) and PCT using the "toggling table" technique within the first three hours after symptom onset. In patients with successful thrombolytic therapy (n = 48) and in those without effective thrombolytic therapy (n = 41), the infarct volume and the volume of the penumbra on PCT were compared to the infarct size on follow-up images (CT or MRI) performed within 8 days. The feasibility of complete infarct volume prediction by 8 cm cranio-caudal coverage was evaluated. The correlation between the volume of hypoperfusion on PCT defined by cerebral blood volume reduction and final infarct volume was strongest in patients with successful thrombolytic therapy with underestimation of the definite infarct volume by 8.5 ml on average. The CBV map had the greatest prognostic value. In patients without successful thrombolytic therapy, the final infarct volume was overestimated by 12.1 ml compared to the MTT map on PCT. All infarcts were detected completely. There were no false-positive or false-negative results. Using PCT and the "toggling table" technique in acute stroke patients is helpful for the rapid and accurate quantification of the minimal final infarct and is therefore a prognostic parameter which has to be evaluated in further studies to assess its impact on therapeutic decision. ▶ Using PCT and the “toggling table technique” allows accurate quantification of the infarct core and penumbra. ▶ It is possible to record dynamic perfusion parameters quickly and easily of almost the entire supratentorial brain volume on a 64-slice MDCT unit. ▶ The technique allows identification of those patients who could profit from thrombolytic therapy outside the established time intervals. © Georg Thieme Verlag

Acute and chronic glucocorticoid treatments regulate astrocyte-enriched mRNAs in multiple brain regions in vivo

Directory of Open Access Journals (Sweden)

Bradley S. Carter

2013-08-01

Full Text Available Previous studies have primarily interpreted gene expression regulation by glucocorticoids in the brain in terms of impact on neurons; however, less is known about the corresponding impact of glucocorticoids on glia and specifically astrocytes in vivo. Recent microarray experiments have identified glucocorticoid-sensitive mRNAs in primary astrocyte cell culture, including a number of mRNAs that have reported astrocyte-enriched expression patterns relative to other brain cell types. Here, we have tested whether elevations of glucocorticoids regulate a subset of these mRNAs in vivo following acute and chronic corticosterone exposure in adult mice. Acute corticosterone exposure was achieved by a single injection of 10 mg/kg corticosterone, and tissue samples were harvested two hours post-injection. Chronic corticosterone exposure was achieved by administering 10 mg/mL corticosterone via drinking water for two weeks. Gene expression was then assessed in two brain regions associated with glucocorticoid action (prefrontal cortex and hippocampus by qPCR and by in situ hybridization. The majority of measured mRNAs regulated by glucocorticoids in astrocytes in vitro were similarly regulated by acute and/or chronic glucocorticoid exposure in vivo. In addition, the expression levels for mRNAs regulated in at least one corticosterone exposure condition (acute/chronic demonstrated moderate positive correlation between the two conditions by brain region. In situ hybridization analyses suggest that select mRNAs are regulated by chronic corticosterone exposure specifically in astroctyes based on (1 similar general expression patterns between corticosterone-treated and vehicle-treated animals and (2 similar expression patterns to the pan-astrocyte marker Aldh1l1. Our findings demonstrate that glucocorticoids regulate astrocyte-enriched mRNAs in vivo and suggest that glucocorticoids regulate gene expression in the brain in a cell type-dependent fashion.

CT perfusion scanning of the brain in stroke and beyond

International Nuclear Information System (INIS)

Riedel, Christian

2011-01-01

CT perfusion scanning (CTP) allows for quantitative analysis of cerebral blood flow (CBF) and cerebral blood volume (CBV). Until recently, it was only possible to study brain perfusion parameters in a small stack of CT-slices close to the skull base. With the introduction of multidetector CT scanners with 64 and more detector rows it has become possible to assess perfusion of the entire brain. An optimal choice of scanning parameters like the new 'shuttle'-technique combined with a well adapted regimen for contrast administration is required to guarantee reliable perfusion measurements while still keeping the X-ray dose absorbed by the patient at a minimum. With these techniques, CTP is not only an important modality in the work-up of patients suffering from acute ischemic stroke but can also be valuable in other emergency situations such as in prolonged epileptic seizures or to monitor patients with subacute subarachnoid hemorrhage. (orig.)

How Acute Total Sleep Loss Affects the Attending Brain: A Meta-Analysis of Neuroimaging Studies

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Ma, Ning; Dinges, David F.; Basner, Mathias; Rao, Hengyi

2015-01-01

Study Objectives: Attention is a cognitive domain that can be severely affected by sleep deprivation. Previous neuroimaging studies have used different attention paradigms and reported both increased and reduced brain activation after sleep deprivation. However, due to large variability in sleep deprivation protocols, task paradigms, experimental designs, characteristics of subject populations, and imaging techniques, there is no consensus regarding the effects of sleep loss on the attending brain. The aim of this meta-analysis was to identify brain activations that are commonly altered by acute total sleep deprivation across different attention tasks. Design: Coordinate-based meta-analysis of neuroimaging studies of performance on attention tasks during experimental sleep deprivation. Methods: The current version of the activation likelihood estimation (ALE) approach was used for meta-analysis. The authors searched published articles and identified 11 sleep deprivation neuroimaging studies using different attention tasks with a total of 185 participants, equaling 81 foci for ALE analysis. Results: The meta-analysis revealed significantly reduced brain activation in multiple regions following sleep deprivation compared to rested wakefulness, including bilateral intraparietal sulcus, bilateral insula, right prefrontal cortex, medial frontal cortex, and right parahippocampal gyrus. Increased activation was found only in bilateral thalamus after sleep deprivation compared to rested wakefulness. Conclusion: Acute total sleep deprivation decreases brain activation in the fronto-parietal attention network (prefrontal cortex and intraparietal sulcus) and in the salience network (insula and medial frontal cortex). Increased thalamic activation after sleep deprivation may reflect a complex interaction between the de-arousing effects of sleep loss and the arousing effects of task performance on thalamic activity. Citation: Ma N, Dinges DF, Basner M, Rao H. How acute total

Protective effect of grifolin against brain injury in an acute cerebral ...

African Journals Online (AJOL)

Purpose: To evaluate the protective effects of grifolin against brain injury in an acute cerebral ischemia rat model. Methods: Rats were assigned to five groups: control, negative control, and grifolin (50, 100, and 200 mg/kg, p.o.) treated groups, which received the drug for 2 weeks. All the animals were sacrificed at the end of ...

A Simulation-based Approach for Improving Utilization of Thrombolysis in Acute Brain Infarction

NARCIS (Netherlands)

Lahr, M. M. H.; van der Zee, D. J.; Luijckx, G. J.; Vroomen, Patrick; Buskens, E.

2013-01-01

BACKGROUND: Treatment with tissue plasminogen activator (tPA) is the most effective treatment in acute brain infarction. However, estimated worldwide treatment rates are <10%, with many barriers hampering broad implementation. Organization and resource-intense randomized controlled trials cannot

The brain is a target organ after acute exposure to depleted uranium

International Nuclear Information System (INIS)

Lestaevel, P.; Houpert, P.; Bussy, C.; Dhieux, B.; Gourmelon, P.; Paquet, F.

2005-01-01

The health effects of depleted uranium (DU) are mainly caused by its chemical toxicity. Although the kidneys are the main target organs for uranium toxicity, uranium can also reach the brain. In this paper, the central effects of acute exposure to DU were studied in relation to health parameters and the sleep-wake cycle of adult rats. Animals were injected intraperitoneally with 144 ± 10 μg DU kg -1 as nitrate. Three days after injection, the amounts of uranium in the kidneys represented 2.6 μg of DU g -1 of tissue, considered as a sub-nephrotoxic dosage. The central effect of uranium could be seen through a decrease in food intake as early as the first day after exposure and shorter paradoxical sleep 3 days after acute DU exposure (-18% of controls). With a lower dosage of DU (70 ± 8 μg DU kg -1 ), no significant effect was observed on the sleep-wake cycle. The present study intends to illustrate the fact that the brain is a target organ, as are the kidneys, after acute exposure to a moderate dosage of DU. The mechanisms by which uranium causes these early neurophysiological perturbations shall be discussed

Ethanol induces MAP2 changes in organotypic hippocampal slice cultures

DEFF Research Database (Denmark)

Noraberg, J; Zimmer, J

1998-01-01

loss of CA3 pyramidal cells and moderate loss of dentate granule cells, as seen in vivo. The results indicate that brain slice cultures combined with immunostaining for cytoskeleton and neuronal markers can be used for studies of ethanol and organic solvent neurotoxicity.......Microtubule-associated protein 2 (MAP2) and neuron-specific protein (NeuN) immunostains were used to demonstrate neurotoxic effects in mature hippocampal slice cultures exposed to ethanol (50, 100, 200 mM) for 4 weeks. At the low dose the density of MAP2 immunostaining in the dentate molecular...... layer was 118% of the control cultures, with no detectable changes in CA1 and CA3. At 100 mM no changes were detected, while 200 mM ethanol significantly reduced the MAP2 density in both dentate (19%) and hippocampal dendritic fields (CA3, 52%; CA1, 55%). At this dose NeuN staining showed considerable...

Gelatin promotes rapid restoration of the blood brain barrier after acute brain injury.

Science.gov (United States)

Kumosa, Lucas S; Zetterberg, Valdemar; Schouenborg, Jens

2018-01-01

Gelatin coating of brain implants is known to provide considerable benefits in terms of reduced inflammatory sequalae and long-term neuroprotective effects. However, the mechanisms for gelatin's protective role in brain injury are still unknown. To address this question, cellular and molecular markers were studied with quantitative immunohistochemical microscopy at acute (implantable devices for stimulation based therapy. Currently, this field is struggling to find solutions for reducing tissue reactions to implanted micro and nanotechnology. Prior studies have recently shown that gelatin coatings lower activation of digestive microglia and mitigate the ubiquitous loss of neurons adjacent to implanted probes, both of which impede implant function. The underlying mechanisms remain to be elucidated, however. Our findings demonstrate for the first time that gelatin has a significant effect on the BBB by promoting rapid restoration of integrity after injury. Moreover, gelatin alters microglia phenotypes and modulates gelatinase activity for up to 2weeks favoring anti-inflammation and restoration of the tissue. Given the key importance of the BBB for normal brain functions, we believe our findings have substantial significance and will be highly interesting to researchers in the biomaterial field. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

The impact of aging, hearing loss, and body weight on mouse hippocampal redox state, measured in brain slices using fluorescence imaging.

Science.gov (United States)

Stebbings, Kevin A; Choi, Hyun W; Ravindra, Aditya; Llano, Daniel Adolfo

2016-06-01

The relationships between oxidative stress in the hippocampus and other aging-related changes such as hearing loss, cortical thinning, or changes in body weight are not yet known. We measured the redox ratio in a number of neural structures in brain slices taken from young and aged mice. Hearing thresholds, body weight, and cortical thickness were also measured. We found striking aging-related increases in the redox ratio that were isolated to the stratum pyramidale, while such changes were not observed in thalamus or cortex. These changes were driven primarily by changes in flavin adenine dinucleotide, not nicotinamide adenine dinucleotide hydride. Multiple regression analysis suggested that neither hearing threshold nor cortical thickness independently contributed to this change in hippocampal redox ratio. However, body weight did independently contribute to predicted changes in hippocampal redox ratio. These data suggest that aging-related changes in hippocampal redox ratio are not a general reflection of overall brain oxidative state but are highly localized, while still being related to at least one marker of late aging, weight loss at the end of life. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessment of brain perfusion with MRI: methodology and application to acute stroke

International Nuclear Information System (INIS)

Grandin, C.B.

2003-01-01

We review the methodology of brain perfusion measurements with MRI and their application to acute stroke, with particular emphasis on the work awarded by the 6th Lucien Appel Prize for Neuroradiology. The application of the indicator dilution theory to the dynamic susceptibility-weighted bolus-tracking method is explained, as is the approach to obtaining quantitative measurements of cerebral blood flow (CBF) and volume (CBV). Our contribution to methodological developments, such as CBV measurement with the frequency-shifted burst sequence, development of the PRESTO sequence, comparison of different deconvolution methods and of spin- and gradient-echo sequences, and the validation of MRI measurements against positron emission tomography is summarised. The pathophysiology of brain ischaemia and the role of neuroimaging in the setting of acute stroke are reviewed, with an introduction to the concepts of ischaemic penumbra and diffusion/perfusion mismatch. Our work on the determination of absolute CBF and CBV thresholds for predicting the area of infarct growth, identification of the best perfusion parameters (relative or absolute) for predicting the area of infarct growth and the role of MR angiography is also summarised. We conclude that MRI is a very powerful way to assess brain perfusion and that its use might help in selecting patients who will benefit most from treatment such as thrombolysis. (orig.)

Brain Volume Estimation Enhancement by Morphological Image Processing Tools

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Zeinali R.

2017-12-01

Full Text Available Background: Volume estimation of brain is important for many neurological applications. It is necessary in measuring brain growth and changes in brain in normal/ abnormal patients. Thus, accurate brain volume measurement is very important. Magnetic resonance imaging (MRI is the method of choice for volume quantification due to excellent levels of image resolution and between-tissue contrast. Stereology method is a good method for estimating volume but it requires to segment enough MRI slices and have a good resolution. In this study, it is desired to enhance stereology method for volume estimation of brain using less MRI slices with less resolution. Methods: In this study, a program for calculating volume using stereology method has been introduced. After morphologic method, dilation was applied and the stereology method enhanced. For the evaluation of this method, we used T1-wighted MR images from digital phantom in BrainWeb which had ground truth. Results: The volume of 20 normal brain extracted from BrainWeb, was calculated. The volumes of white matter, gray matter and cerebrospinal fluid with given dimension were estimated correctly. Volume calculation from Stereology method in different cases was made. In three cases, Root Mean Square Error (RMSE was measured. Case I with T=5, d=5, Case II with T=10, D=10 and Case III with T=20, d=20 (T=slice thickness, d=resolution as stereology parameters. By comparing these results of two methods, it is obvious that RMSE values for our proposed method are smaller than Stereology method. Conclusion: Using morphological operation, dilation allows to enhance the estimation volume method, Stereology. In the case with less MRI slices and less test points, this method works much better compared to Stereology method.

Structural Findings in the Brain MRI of Patients with Acute Carbon Monoxide Poisoning

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Yasmin Davoudi

2014-09-01

Conclusion: The white matter and globus pallidus were the most common affected regions in brain following acute CO poisoning. Signal abnormalities and restricted diffusion in MRI were correlated with duration of exposure to CO but not with the carboxyhemoglobin levels.

Lipopolysaccharide does not alter small airway reactivity in mouse lung slices.

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Donovan, Chantal; Royce, Simon G; Vlahos, Ross; Bourke, Jane E

2015-01-01

The bacterial endotoxin, lipopolysaccharide (LPS) has been associated with occupational airway diseases with asthma-like symptoms and in acute exacerbations of COPD. The direct and indirect effects of LPS on small airway reactivity have not been fully elucidated. We tested the hypothesis that both in vitro and in vivo LPS treatment would increase contraction and impair relaxation of mouse small airways. Lung slices were prepared from naïve Balb/C mice and cultured in the absence or presence of LPS (10 μg/ml) for up to 48 h for measurement of TNFα levels in conditioned media. Alternatively, mice were challenged with PBS or LPS in vivo once a day for 4 days for preparation of lung slices or for harvest of lungs for Q-PCR analysis of gene expression of pro-inflammatory cytokines and receptors involved in airway contraction. Reactivity of small airways to contractile agonists, methacholine and serotonin, and bronchodilator agents, salbutamol, isoprenaline and rosiglitazone, were assessed using phase-contrast microscopy. In vitro LPS treatment of slices increased TNFα release 6-fold but did not alter contraction or relaxation to any agonists tested. In vivo LPS treatment increased lung gene expression of TNFα, IL-1β and ryanodine receptor isoform 2 more than 5-fold. However there were no changes in reactivity in lung slices from these mice, even when also incubated with LPS ex vivo. Despite evidence of LPS-induced inflammation, neither airway hyperresponsiveness or impaired dilator reactivity were evident. The increase in ryanodine receptor isoform 2, known to regulate calcium signaling in vascular smooth muscle, warrants investigation. Since LPS failed to elicit changes in small airway reactivity in mouse lung slices following in vitro or in vivo treatment, alternative approaches are required to define the potential contribution of this endotoxin to altered small airway reactivity in human lung diseases.

Lipopolysaccharide does not alter small airway reactivity in mouse lung slices.

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Chantal Donovan

Full Text Available The bacterial endotoxin, lipopolysaccharide (LPS has been associated with occupational airway diseases with asthma-like symptoms and in acute exacerbations of COPD. The direct and indirect effects of LPS on small airway reactivity have not been fully elucidated. We tested the hypothesis that both in vitro and in vivo LPS treatment would increase contraction and impair relaxation of mouse small airways. Lung slices were prepared from naïve Balb/C mice and cultured in the absence or presence of LPS (10 μg/ml for up to 48 h for measurement of TNFα levels in conditioned media. Alternatively, mice were challenged with PBS or LPS in vivo once a day for 4 days for preparation of lung slices or for harvest of lungs for Q-PCR analysis of gene expression of pro-inflammatory cytokines and receptors involved in airway contraction. Reactivity of small airways to contractile agonists, methacholine and serotonin, and bronchodilator agents, salbutamol, isoprenaline and rosiglitazone, were assessed using phase-contrast microscopy. In vitro LPS treatment of slices increased TNFα release 6-fold but did not alter contraction or relaxation to any agonists tested. In vivo LPS treatment increased lung gene expression of TNFα, IL-1β and ryanodine receptor isoform 2 more than 5-fold. However there were no changes in reactivity in lung slices from these mice, even when also incubated with LPS ex vivo. Despite evidence of LPS-induced inflammation, neither airway hyperresponsiveness or impaired dilator reactivity were evident. The increase in ryanodine receptor isoform 2, known to regulate calcium signaling in vascular smooth muscle, warrants investigation. Since LPS failed to elicit changes in small airway reactivity in mouse lung slices following in vitro or in vivo treatment, alternative approaches are required to define the potential contribution of this endotoxin to altered small airway reactivity in human lung diseases.

Transient ischemic attacks and presence of an acute brain lesion in diffusion-weighted MRI: study of 50 patients

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Sabeti M

2012-10-01

Full Text Available Background: Finding an acute brain lesion by diffusion-weighted (DW MRI upon an episode of transient ischemic attack (TIA is a predictor of imminent stroke in the near future. Therefore, exploring risk factors associated with lesions in DW-MRI of the brain is important in adopting an approach to TIA management. In the current study, we tried to determine the risk factors associated with lesions in DW-MRI of the brain in patients experiencing TIA episodes.Methods: Fifty patients with TIA were recruited consecutively in Sina Hospital, Tehran, Iran, over a 6-month period between July 2008 and January 2009. All of the patients underwent a complete neurological examination and laboratory tests. Brain DW-MRIs were performed for all the patients within 72 hours of a TIA episode.Results: DW-MRI revealed an acute lesion in 16% of the participants. There was a significant correlation between presence of an acute lesion in DW-MRI and TIA duration, history of diabetes mellitus and presence of unilateral facial palsy (P=0.0003, P=0.02 and P=0.008, respectively. Other variables such as age, hypertension, hyperlipidemia, past history of TIA, headache, vertigo, and sensory or visual disturbances had no significant relation with the presence of an acute lesion in DW-MRI.Conclusion: Duration of TIA, presence of diabetes mellitus and unilateral facial palsy are risk factors for an acute lesion in DW-MRI, meaning that patients with such risk factors are at risk for stroke in the near future.

Association of acute adverse effects with high local SAR induced in the brain from prolonged RF head and neck hyperthermia

International Nuclear Information System (INIS)

Adibzadeh, F; Verhaart, R F; Rijnen, Z; Franckena, M; Van Rhoon, G C; Paulides, M M; Verduijn, G M; Fortunati, V

2015-01-01

To provide an adequate level of protection for humans from exposure to radio-frequency (RF) electromagnetic fields (EMF) and to assure that any adverse health effects are avoided. The basic restrictions in terms of the specific energy absorption rate (SAR) were prescribed by IEEE and ICNIRP. An example of a therapeutic application of non-ionizing EMF is hyperthermia (HT), in which intense RF energy is focused at a target region. Deep HT in the head and neck (H and N) region involves inducing energy at 434 MHz for 60 min on target. Still, stray exposure of the brain is considerable, but to date only very limited side-effects were observed. The objective of this study is to investigate the stringency of the current basic restrictions by relating the induced EM dose in the brain of patients treated with deep head and neck (H and N) HT to the scored acute health effects. We performed a simulation study to calculate the induced peak 10 g spatial-averaged SAR (psSAR 10g ) in the brains of 16 selected H and N patients who received the highest SAR exposure in the brain, i.e. who had the minimum brain-target distance and received high forwarded power during treatment. The results show that the maximum induced SAR in the brain of the patients can exceed the current basic restrictions (IEEE and ICNIRP) on psSAR 10g for occupational environments by 14 times. Even considering the high local SAR in the brain, evaluation of acute effects by the common toxicity criteria (CTC) scores revealed no indication of a serious acute neurological effect. In addition, this study provides pioneering quantitative human data on the association between maximum brain SAR level and acute adverse effects when brains are exposed to prolonged RF EMF. (paper)

Volumetric Integral Phase-shift Spectroscopy for Noninvasive Detection of Hemispheric Bioimpedance Asymmetry in Acute Brain Pathology

Science.gov (United States)

2018-05-10

Stroke; Stroke, Acute; Ischemic Stroke; Hemorrhage; Clot (Blood); Brain; Subarachnoid Hemorrhage; Cerebral Infarction; Cerebral Hemorrhage; Cerebral Stroke; Intracerebral Hemorrhage; Intracerebral Injury

Functional MRI for Assessment of the Default Mode Network in Acute Brain Injury

DEFF Research Database (Denmark)

Kondziella, Daniel; Fisher, Patrick M.; Larsen, Vibeke Andrée

2017-01-01

more challenging in critically ill patients because of cardiovascular vulnerability, intravenous sedation, and artificial ventilation. Methods: Using resting-state fMRI, we investigated the DMN in a convenience sample of patients with acute brain injury admitted to the intensive care unit. The DMN...

Higher transport and metabolism of glucose in astrocytes compared with neurons: a multiphoton study of hippocampal and cerebellar tissue slices.

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Jakoby, Patrick; Schmidt, Elke; Ruminot, Iván; Gutiérrez, Robin; Barros, L Felipe; Deitmer, Joachim W

2014-01-01

Glucose is the most important energy substrate for the brain, and its cellular distribution is a subject of great current interest. We have employed fluorescent glucose probes, the 2-deoxy-D-glucose derivates 6- and 2-([N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose) (2-NBDG), to measure transport and metabolism of glucose in acute slices of mouse hippocampus and cerebellum. In the hippocampus, 6-NBDG, which is not metabolized and hence indicates glucose transport, was taken up faster in astrocyte-rich layers (Stratum radiatum [S.r.], Stratum oriens [S.o.]) than in pyramidal cells. Metabolizable 2-NBDG showed larger signals in S.r. and S.o. than in Stratum pyramidale, suggesting faster glucose utilization rate in the astrocyte versus the neuronal compartment. Similarly, we found higher uptake and temperature-sensitive metabolism of 2-NBDG in Bergmann glia when compared with adjacent Purkinje neurons of cerebellar slices. A comparison between 6-NBDG transport and glucose transport in cultured cells using a fluorescence resonance energy transfer nanosensor showed that relative to glucose, 6-NBDG is transported better by neurons than by astrocytes. These results indicate that the preferential transport and metabolism of glucose by glial cells versus neurons proposed for the hippocampus and cerebellum by ourselves (in vitro) and for the barrel cortex by Chuquet et al. (in vivo) is more pronounced than anticipated.

The virtual slice setup.

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Lytton, William W; Neymotin, Samuel A; Hines, Michael L

2008-06-30

In an effort to design a simulation environment that is more similar to that of neurophysiology, we introduce a virtual slice setup in the NEURON simulator. The virtual slice setup runs continuously and permits parameter changes, including changes to synaptic weights and time course and to intrinsic cell properties. The virtual slice setup permits shocks to be applied at chosen locations and activity to be sampled intra- or extracellularly from chosen locations. By default, a summed population display is shown during a run to indicate the level of activity and no states are saved. Simulations can run for hours of model time, therefore it is not practical to save all of the state variables. These, in any case, are primarily of interest at discrete times when experiments are being run: the simulation can be stopped momentarily at such times to save activity patterns. The virtual slice setup maintains an automated notebook showing shocks and parameter changes as well as user comments. We demonstrate how interaction with a continuously running simulation encourages experimental prototyping and can suggest additional dynamical features such as ligand wash-in and wash-out-alternatives to typical instantaneous parameter change. The virtual slice setup currently uses event-driven cells and runs at approximately 2 min/h on a laptop.

Cognitive benefit and cost of acute stress is differentially modulated by individual brain state

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Hermans, Erno J.; Fernández, Guillén

2017-01-01

Abstract Acute stress is associated with beneficial as well as detrimental effects on cognition in different individuals. However, it is not yet known how stress can have such opposing effects. Stroop-like tasks typically show this dissociation: stress diminishes speed, but improves accuracy. We investigated accuracy and speed during a stroop-like task of 120 healthy male subjects after an experimental stress induction or control condition in a randomized, counter-balanced cross-over design; we assessed brain–behavior associations and determined the influence of individual brain connectivity patterns on these associations, which may moderate the effect and help identify stress resilience factors. In the mean, stress was associated to increase in accuracy, but decrease in speed. Accuracy was associated to brain activation in a distributed set of brain regions overlapping with the executive control network (ECN) and speed to temporo-parietal activation. In line with a stress-related large-scale network reconfiguration, individuals showing an upregulation of the salience and down-regulation of the executive-control network under stress displayed increased speed, but decreased performance. In contrast, individuals who upregulate their ECN under stress show improved performance. Our results indicate that the individual large-scale brain network balance under acute stress moderates cognitive consequences of threat. PMID:28402480

Induksi Ginogenesis melalui Kultur Multi Ovule Slice dan Kultur Ovary Slice Dianthus chinensis

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Suskandari Kartikaningrum

2013-10-01

Full Text Available Callus induction was studied in five genotypes of Dianthus chinensis using 2.4 D and NAA. Calluses can be obtainedfrom unfertilized ovule culture and ovary culture. The aim of the research was to study gynogenic potential and responseof Dianthus chinensis through ovule slice and ovary slice culture for obtaining haploid plants. Five genotypes of Dianthuschinensis and five media were used in ovule slice culture and two genotypes and three medium were used in ovary culture.Flower buds in the 7th stage were incubated for the purpose of dark pre-treatment at 4 oC for one day. Ovules and ovaries wereisolated and cultured in induction medium. Cultures were incubated for the purpose of dark pre-treatment at 4 oC for seven days, followed by 25 oC light incubation. The result showed that 2.4D was better than NAA in inducing callus. Percentage of regenerated calluses were produced in V11, V13 and V15 genotypes in M7 medium (MS + 2 mg L-1 2.4D + 1 mg L-1 BAP + 30 g L-1 sucrose and M10 medium (MS + 1 mg L-1 2.4D + 1 mg L-1 BAP + 20 g L-1 sucrose. All calluses originated from ovule and ovary cultures flowered prematurely. Double haploid (V11-34 were obtained from ovule slice culture based on PER (peroksidase and EST (esterase isoenzym marker.Keywords: ovule slice culture, ovary slice culture, callus, Dianthus sp., haploid

Banking for the future: an Australian experience in brain banking.

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Sarris, M; Garrick, T M; Sheedy, D; Harper, C G

2002-06-01

The New South Wales (NSW) Tissue Resource Centre (TRC) has been set up to provide Australian and international researchers with fixed and frozen brain tissue from cases that are well characterised, both clinically and pathologically, for projects related to neuropsychiatric and alcohol-related disorders. A daily review of the Department of Forensic Medicine provides initial information regarding a potential collection. If the case adheres to the strict inclusion criteria, the pathologist performing the postmortem examination is approached regarding retention of the brain tissue. The next of kin of the deceased is then contacted requesting permission to retain the brain for medical research. Cases are also obtained through donor programmes, where donors are assessed and consent to donate their brain during life. Once the brain is removed at autopsy, the brain is photographed, weighed and the volume determined, the brainstem and cerebellum are removed. The two hemispheres are divided, one hemisphere is fresh frozen and one fixed (randomised). Prior to freezing, the hemisphere is sliced into 1-cm coronal slices and a set of critical area blocks is taken. All frozen tissues are kept bagged at -80 degrees C. The other hemisphere is fixed in 15% buffered formalin for 2 weeks, embedded in agar and sliced at 3-mm intervals in the coronal plane. Tissue blocks from these slices are used for neuropathological analysis to exclude any other pathology. The TRC currently has 230 cases of both fixed and frozen material that has proven useful in a range of techniques in many research projects. These techniques include quantitative analyses of brain regions using neuropathological, neurochemical, neuropharmacological and gene expression assays.

Brain-lung crosstalk in critical care: how protective mechanical ventilation can affect the brain homeostasis.

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Mazzeo, A T; Fanelli, V; Mascia, L

2013-03-01

The maintenance of brain homeostasis against multiple internal and external challenges occurring during the acute phase of acute brain injury may be influenced by critical care management, especially in its respiratory, hemodynamic and metabolic components. The occurrence of acute lung injury represents the most frequent extracranial complication after brain injury and deserves special attention in daily practice as optimal ventilatory strategy for patients with acute brain and lung injury are potentially in conflict. Protecting the lung while protecting the brain is thus a new target in the modern neurointensive care. This article discusses the essentials of brain-lung crosstalk and focuses on how mechanical ventilation may exert an active role in the process of maintaining or treatening brain homeostasis after acute brain injury, highlighting the following points: 1) the role of inflammation as common pathomechanism of both acute lung and brain injury; 2) the recognition of ventilatory induced lung injury as determinant of systemic inflammation affecting distal organs, included the brain; 3) the possible implication of protective mechanical ventilation strategy on the patient with an acute brain injury as an undiscovered area of research in both experimental and clinical settings.

Acute administration of fenproporex increased acetylcholinesterase activity in brain of young rats.

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Teodorak, Brena P; Ferreira, Gabriela K; Scaini, Giselli; Wessler, Letícia B; Heylmann, Alexandra S; Deroza, Pedro; Valvassori, Samira S; Zugno, Alexandra I; Quevedo, João; Streck, Emilio L

2015-08-01

Fenproporex is the second most commonly amphetamine-based anorectic consumed worldwide; this drug is rapidly converted into amphetamine, in vivo, and acts by increasing dopamine levels in the synaptic cleft. Considering that fenproporex effects on the central nervous system are still poorly known and that acetylcholinesterase is a regulatory enzyme which is involved in cholinergic synapses and may indirectly modulate the release of dopamine, the present study investigated the effects of acute administration of fenproporex on acetylcholinesterase activity in brain of young rats. Young male Wistar rats received a single injection of fenproporex (6.25, 12.5 or 25mg/kg i.p.) or vehicle (2% Tween 80). Two hours after the injection, the rats were killed by decapitation and the brain was removed for evaluation of acetylcholinesterase activity. Results showed that fenproporex administration increased acetylcholinesterase activity in the hippocampus and posterior cortex, whereas in the prefrontal cortex, striatum and cerebellum the enzyme activity was not altered. In conclusion, in the present study we demonstrated that acute administration of fenproporex exerts an effect in the cholinergic system causing an increase in the activity of acetylcholinesterase in a dose-dependent manner in the hippocampus and posterior cortex. Thus, we suggest that the imbalance in cholinergic homeostasis could be considered as an important pathophysiological mechanism underlying the brain damage observed in patients who use amphetamines such as fenproporex.

Acute administration of fenproporex increased acetylcholinesterase activity in brain of young rats

Directory of Open Access Journals (Sweden)

BRENA P. TEODORAK

2015-08-01

Full Text Available Fenproporex is the second most commonly amphetamine-based anorectic consumed worldwide; this drug is rapidly converted into amphetamine, in vivo, and acts by increasing dopamine levels in the synaptic cleft. Considering that fenproporex effects on the central nervous system are still poorly known and that acetylcholinesterase is a regulatory enzyme which is involved in cholinergic synapses and may indirectly modulate the release of dopamine, the present study investigated the effects of acute administration of fenproporex on acetylcholinesterase activity in brain of young rats. Young male Wistar rats received a single injection of fenproporex (6.25, 12.5 or 25mg/kg i.p. or vehicle (2% Tween 80. Two hours after the injection, the rats were killed by decapitation and the brain was removed for evaluation of acetylcholinesterase activity. Results showed that fenproporex administration increased acetylcholinesterase activity in the hippocampus and posterior cortex, whereas in the prefrontal cortex, striatum and cerebellum the enzyme activity was not altered. In conclusion, in the present study we demonstrated that acute administration of fenproporex exerts an effect in the cholinergic system causing an increase in the activity of acetylcholinesterase in a dose-dependent manner in the hippocampus and posterior cortex. Thus, we suggest that the imbalance in cholinergic homeostasis could be considered as an important pathophysiological mechanism underlying the brain damage observed in patients who use amphetamines such as fenproporex.

Fully-automated computer-assisted method of CT brain scan analysis for the measurement of cerebrospinal fluid spaces and brain absorption density

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Baldy, R.E.; Brindley, G.S.; Jacobson, R.R.; Reveley, M.A.; Lishman, W.A.; Ewusi-Mensah, I.; Turner, S.W.

1986-03-01

Computer-assisted methods of CT brain scan analysis offer considerable advantages over visual inspection, particularly in research; and several semi-automated methods are currently available. A new computer-assisted program is presented which provides fully automated processing of CT brain scans, depending on ''anatomical knowledge'' of where cerebrospinal fluid (CSF)-containing spaces are likely to lie. After identifying these regions of interest quantitative estimates are then provided of CSF content in each slice in cisterns, ventricles, Sylvian fissure and interhemispheric fissure. Separate measures are also provided of mean brain density in each slice. These estimates can be summated to provide total ventricular and total brain volumes. The program shows a high correlation with measures derived from mechanical planimetry and visual grading procedures, also when tested against a phantom brain of known ventricular volume. The advantages and limitations of the present program are discussed.

Prominent hypointense veins on susceptibility weighted image in the cat brain with acute infarction: DWI, SWI, and PWI.

Science.gov (United States)

Kim, Yong-Woo; Kim, Hak Jin; Choi, Seon Hee; Kim, Dong Chan

2014-10-01

The multiple prominent hypointense veins on susceptibility-weighted imaging (SWI) have been found in the ischemic territory of patients with acute ischemic stroke. Venous side is the unknown area in the hemodynamics of brain infarction. To evaluate the venous aspect in acute brain infarction through an animal study. The acute infarction in cat brains was induced with a bolus infusion of 0.25 mL of triolein through one side of the common carotid artery. The magnetic resonance (MR) images, including diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) map, SW, and perfusion-weighted (PWI) images, were obtained serially at 2 h (n = 17), 1 day (n = 11), and 4 days (n = 4) after triolein infusion. The obtained MR images were evaluated qualitatively and quantitatively. For qualitative assessment, the signal intensity of the serial MR images was evaluated. The presence or absence and the location with serial changes of infarction were identified on DWI and ADC map images. The presence or absence of prominent hypointense veins and the serial changes of cortical veins were also evaluated on SWI. Quantitative assessment was performed by comparing the relative cerebral blood volume (rCBV), cerebral blood flow (rCBF), and mean transit times (MTT) of the lesions with those of the contralateral normal side calculated on PWI. The serial changes of rCBV, rCBF, and MTT ratio were also evaluated. Acute infarction in the first and second medial gyrus of lesion hemisphere was found by qualitative evaluation of DWI and ADC map images. On the serial evaluation of SWI, the cortical veins of cat brain with infarction were obscured at 2 h and then re-appeared at 1 day. The hemorrhage transformation and prominent hypointense veins were seen at 4 days on SWI. The quantitative evaluation revealed increased MTT ratios and decreased rCBV and rCBF ratios on PWIs in the acute infarction of cat brain. The prominent hypointense veins on SWI were seen in the half of the acute

Multiple single-unit long-term tracking on organotypic hippocampal slices using high-density microelectrode arrays

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Wei Gong

2016-11-01

Full Text Available A novel system to cultivate and record from organotypic brain slices directly on high-density microelectrode arrays (HD-MEA was developed. This system allows for continuous recording of electrical activity of specific individual neurons at high spatial resolution while monitoring at the same time, neuronal network activity. For the first time, the electrical activity patterns of single neurons and the corresponding neuronal network in an organotypic hippocampal slice culture were studied during several consecutive weeks at daily intervals. An unsupervised iterative spike-sorting algorithm, based on PCA and k-means clustering, was developed to assign the activities to the single units. Spike-triggered average extracellular waveforms of an action potential recorded across neighboring electrodes, termed ‘footprints’ of single-units were generated and tracked over weeks. The developed system offers the potential to study chronic impacts of drugs or genetic modifications on individual neurons in slice preparations over extended times.

Can multi-slice or navigator-gated R2* MRI replace single-slice breath-hold acquisition for hepatic iron quantification?

International Nuclear Information System (INIS)

Loeffler, Ralf B.; McCarville, M.B.; Song, Ruitian; Hillenbrand, Claudia M.; Wagstaff, Anne W.; Smeltzer, Matthew P.; Krafft, Axel J.; Hankins, Jane S.

2017-01-01

Liver R2* values calculated from multi-gradient echo (mGRE) magnetic resonance images (MRI) are strongly correlated with hepatic iron concentration (HIC) as shown in several independently derived biopsy calibration studies. These calibrations were established for axial single-slice breath-hold imaging at the location of the portal vein. Scanning in multi-slice mode makes the exam more efficient, since whole-liver coverage can be achieved with two breath-holds and the optimal slice can be selected afterward. Navigator echoes remove the need for breath-holds and allow use in sedated patients. To evaluate if the existing biopsy calibrations can be applied to multi-slice and navigator-controlled mGRE imaging in children with hepatic iron overload, by testing if there is a bias-free correlation between single-slice R2* and multi-slice or multi-slice navigator controlled R2*. This study included MRI data from 71 patients with transfusional iron overload, who received an MRI exam to estimate HIC using gradient echo sequences. Patient scans contained 2 or 3 of the following imaging methods used for analysis: single-slice images (n = 71), multi-slice images (n = 69) and navigator-controlled images (n = 17). Small and large blood corrected region of interests were selected on axial images of the liver to obtain R2* values for all data sets. Bland-Altman and linear regression analysis were used to compare R2* values from single-slice images to those of multi-slice images and navigator-controlled images. Bland-Altman analysis showed that all imaging method comparisons were strongly associated with each other and had high correlation coefficients (0.98 ≤ r ≤ 1.00) with P-values ≤0.0001. Linear regression yielded slopes that were close to 1. We found that navigator-gated or breath-held multi-slice R2* MRI for HIC determination measures R2* values comparable to the biopsy-validated single-slice, single breath-hold scan. We conclude that these three R2* methods can be

Can multi-slice or navigator-gated R2* MRI replace single-slice breath-hold acquisition for hepatic iron quantification?

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Loeffler, Ralf B.; McCarville, M.B.; Song, Ruitian; Hillenbrand, Claudia M. [St. Jude Children' s Research Hospital, Diagnostic Imaging, Memphis, TN (United States); Wagstaff, Anne W. [St. Jude Children' s Research Hospital, Diagnostic Imaging, Memphis, TN (United States); Rhodes College, Memphis, TN (United States); University of Alabama at Birmingham School of Medicine, Birmingham, AL (United States); Smeltzer, Matthew P. [St. Jude Children' s Research Hospital, Department of Biostatistics, Memphis, TN (United States); University of Memphis, Division of Epidemiology, Biostatistics, and Environmental Health, School of Public Health, Memphis, TN (United States); Krafft, Axel J. [St. Jude Children' s Research Hospital, Diagnostic Imaging, Memphis, TN (United States); University Hospital Center Freiburg, Department of Radiology, Freiburg (Germany); Hankins, Jane S. [St. Jude Children' s Research Hospital, Department of Hematology, Memphis, TN (United States)

2017-01-15

Liver R2* values calculated from multi-gradient echo (mGRE) magnetic resonance images (MRI) are strongly correlated with hepatic iron concentration (HIC) as shown in several independently derived biopsy calibration studies. These calibrations were established for axial single-slice breath-hold imaging at the location of the portal vein. Scanning in multi-slice mode makes the exam more efficient, since whole-liver coverage can be achieved with two breath-holds and the optimal slice can be selected afterward. Navigator echoes remove the need for breath-holds and allow use in sedated patients. To evaluate if the existing biopsy calibrations can be applied to multi-slice and navigator-controlled mGRE imaging in children with hepatic iron overload, by testing if there is a bias-free correlation between single-slice R2* and multi-slice or multi-slice navigator controlled R2*. This study included MRI data from 71 patients with transfusional iron overload, who received an MRI exam to estimate HIC using gradient echo sequences. Patient scans contained 2 or 3 of the following imaging methods used for analysis: single-slice images (n = 71), multi-slice images (n = 69) and navigator-controlled images (n = 17). Small and large blood corrected region of interests were selected on axial images of the liver to obtain R2* values for all data sets. Bland-Altman and linear regression analysis were used to compare R2* values from single-slice images to those of multi-slice images and navigator-controlled images. Bland-Altman analysis showed that all imaging method comparisons were strongly associated with each other and had high correlation coefficients (0.98 ≤ r ≤ 1.00) with P-values ≤0.0001. Linear regression yielded slopes that were close to 1. We found that navigator-gated or breath-held multi-slice R2* MRI for HIC determination measures R2* values comparable to the biopsy-validated single-slice, single breath-hold scan. We conclude that these three R2* methods can be

Evaluation of the relative biological effectiveness of carbon ion beams in the cerebellum using the rat organotypic slice culture system

International Nuclear Information System (INIS)

Yoshida, Yukari; Katoh, Hiroyuki; Nakano, Takashi; Suzuki, Yoshiyuki; Al-Jahdari, Wael S.; Shirai, Katsuyuki; Hamada, Nobuyuki; Funayama, Tomoo; Sakashita, Tetsuya; Kobayashi, Yasuhiko

2012-01-01

The purpose of this study was to clarify the relative biological effectiveness (RBE) values of carbon ion (C) beams in normal brain tissues, a rat organotypic slice culture system was used. The cerebellum was dissected from 10-day-old Wistar rats, cut parasagittally into approximately 600-μm-thick slices and cultivated using a membrane-based culture system with a liquid-air interface. Slices were irradiated with 140 kV X-rays and 18.3 MeV/amu C-beams (linear energy transfer=108 keV/μm). After irradiation, the slices were evaluated histopathologically using hematoxylin and eosin staining, and apoptosis was quantified using the TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay. Disorganization of the external granule cell layer (EGL) and apoptosis of the external granule cells (EGCs) were induced within 24 h after exposure to doses of more than 5 Gy from C-beams and X-rays. In the early postnatal cerebellum, morphological changes following exposure to C-beams were similar to those following exposure to X-rays. The RBEs values of C-beams using the EGL disorganization and the EGC TUNEL index endpoints ranged from 1.4 to 1.5. This system represents a useful model for assaying the biological effects of radiation on the brain, especially physiological and time-dependent phenomena. (author)

The action of piracetam on 14C-glucose metabolism in normal and posthypoxic rat cerebral cortex slices

International Nuclear Information System (INIS)

Domanska-Janik, K.; Zaleska, M.

1977-01-01

The stimulating effect of piracetam on the respiration and glycolysis was observed in rat brain cortex slices incubated under oxygen atmosphere. After preincubation of the slices under pure nitrogen atmosphere, piracetam influenced also decarboxylation of the C 1 -glucose carbon, indicating stimulation of the pentose cycle. Any significant effect of piracetam on the lowered by anoxia incorporation of 14 C from U- 14 C-glucose into macromolecular fractions was not observed. The results have supported a protective effect of piracetam against oxygen deficiency, caused mainly by stimulation of metabolic glucose pathways, connected with energy production in CNS. (author)

Comparison of 640-Slice Multidetector Computed Tomography Versus 32-Slice MDCT for Imaging of the Osteo-odonto-keratoprosthesis Lamina.

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Norris, Joseph M; Kishikova, Lyudmila; Avadhanam, Venkata S; Koumellis, Panos; Francis, Ian S; Liu, Christopher S C

2015-08-01

To investigate the efficacy of 640-slice multidetector computed tomography (MDCT) for detecting osteo-odonto laminar resorption in the osteo-odonto-keratoprosthesis (OOKP) compared with the current standard 32-slice MDCT. Explanted OOKP laminae and bone-dentine fragments were scanned using 640-slice MDCT (Aquilion ONE; Toshiba) and 32-slice MDCT (LightSpeed Pro32; GE Healthcare). Pertinent comparisons including image quality, radiation dose, and scanning parameters were made. Benefits of 640-slice MDCT over 32-slice MDCT were shown. Key comparisons of 640-slice MDCT versus 32-slice MDCT included the following: percentage difference and correlation coefficient between radiological and anatomical measurements, 1.35% versus 3.67% and 0.9961 versus 0.9882, respectively; dose-length product, 63.50 versus 70.26; rotation time, 0.175 seconds versus 1.000 seconds; and detector coverage width, 16 cm versus 2 cm. Resorption of the osteo-odonto lamina after OOKP surgery can result in potentially sight-threatening complications, hence it warrants regular monitoring and timely intervention. MDCT remains the gold standard for radiological assessment of laminar resorption, which facilitates detection of subtle laminar changes earlier than the onset of clinical signs, thus indicating when preemptive measures can be taken. The 640-slice MDCT exhibits several advantages over traditional 32-slice MDCT. However, such benefits may not offset cost implications, except in rare cases, such as in young patients who might undergo years of radiation exposure.

Radiation exposure in multi-slice versus single-slice spiral CT: results of a nationwide survey

International Nuclear Information System (INIS)

Brix, G.; Nagel, H.D.; Stamm, G.; Veit, R.; Lechel, U.; Griebel, J.; Galanski, M.

2003-01-01

Multi-slice (MS) technology increases the efficacy of CT procedures and offers new promising applications. The expanding use of MSCT, however, may result in an increase in both frequency of procedures and levels of patient exposure. It was, therefore, the aim of this study to gain an overview of MSCT examinations conducted in Germany in 2001. All MSCT facilities were requested to provide information about 14 standard examinations with respect to scan parameters and frequency. Based on this data, dosimetric quantities were estimated using an experimentally validated formalism. Results are compared with those of a previous survey for single-slice (SS) spiral CT scanners. According to the data provided for 39 dual- and 73 quad-slice systems, the average annual number of patients examined at MSCT is markedly higher than that examined at SSCT scanners (5500 vs 3500). The average effective dose to patients was changed from 7.4 mSv at single-slice to 5.5 mSv and 8.1 mSv at dual- and quad-slice scanners, respectively. There is a considerable potential for dose reduction at quad-slice systems by an optimisation of scan protocols and better education of the personnel. To avoid an increase in the collective effective dose from CT procedures, a clear medical justification is required in each case. (orig.)

Specific accumulation of 18F-deoxyglucose in three-dimensional long-term cultures of human and rodent brain tissue

International Nuclear Information System (INIS)

Hocke, C.; Prante, O.; Kuwert, T.; Bluemcke, I.; Jeske, I.; Romstoeck, J.; Stefan, H.

2007-01-01

Aim: Organotypic slice cultures (OSC) of human brain specimens represent an intriguing experimental model for translational studies addressing, e.g., stem cell transplantation in neurodegenerative diseases or targeting invasion by malignant glioma ex vivo. However, long-term viability and phenomena of structural reorganization of human OSC remain to be further characterized. Here, we report the use of 18 F-deoxyglucose (FDG) for evaluating the viability of brain slice preparations obtained either from postnatal rats or human hippocampal specimens. Methods: Anatomically well preserved human hippocampi obtained from epilepsy surgery and rat hippocampus slice cultures obtained from six day old Wistar rats were dissected into horizontal slices. The slices were incubated with FDG in phosphate buffered saline up to 1 h, either with or without supplementation of glucose at a concentration of 2.5 mg/ml. Radioactivity within the medium or slice cultures was measured using a gamma-counter. In addition, distribution of radioactivity was autoradiographically visualized and quantified as counts per mm 2 . Results: In rat hippocampal slices, FDG accumulated with 1 300 000 ± 68 000 counts/mm 2 , whereas the incorporation of the radioactive label in human slices was in the order of 1 500 000 ± 370 000 counts/mm 2 . The elevation of glucose concentration within the medium led to a significant three-fold decrease of FDG accumulation in rat slices and to a 2.4-fold decrease in human specimens. Conclusions: FDG accumulated in organotypic brain cultures of human or rodent origin. FDG is thus suited to investigate the viability of OSC. Furthermore, these preparations open new ways to study the factors governing cerebral FDG uptake in brain tissue ex vivo. (orig.)

A fully-automated computer-assisted method of CT brain scan analysis for the measurement of cerebrospinal fluid spaces and brain absorption density

International Nuclear Information System (INIS)

Baldy, R.E.; Brindley, G.S.; Jacobson, R.R.; Reveley, M.A.; Lishman, W.A.; Ewusi-Mensah, I.; Turner, S.W.

1986-01-01

Computer-assisted methods of CT brain scan analysis offer considerable advantages over visual inspection, particularly in research; and several semi-automated methods are currently available. A new computer-assisted program is presented which provides fully automated processing of CT brain scans, depending on ''anatomical knowledge'' of where cerebrospinal fluid (CSF)-containing spaces are likely to lie. After identifying these regions of interest quantitative estimates are then provided of CSF content in each slice in cisterns, ventricles, Sylvian fissure and interhemispheric fissure. Separate measures are also provided of mean brain density in each slice. These estimates can be summated to provide total ventricular and total brain volumes. The program shows a high correlation with measures derived from mechanical planimetry and visual grading procedures, also when tested against a phantom brain of known ventricular volume. The advantages and limitations of the present program are discussed. (orig.)

Acute Alcohol Intoxication in Patients with Mild Traumatic Brain Injury: Characteristics, Recovery and Outcome

NARCIS (Netherlands)

Scheenen, Myrthe; de Koning, Myrthe; van der Horn, Harm; van der Naalt, Joukje; Spikman, Jacoba

2015-01-01

Objectives. To investigate the incidence of acute alcohol intoxication (AAI) at the time of sustaining mild traumatic brain injury (mTBI), describe the characteristics of this intoxicated subgroup, and evaluate recovery and outcome in comparison to sober mTBI patients. Methods. Multicenter cohort

Selective brain responses to acute and chronic low-dose X-ray irradiation in males and females

International Nuclear Information System (INIS)

Silasi, Greg; Diaz-Heijtz, Rochellys; Besplug, Jill; Rodriguez-Juarez, Rocio; Titov, Viktor; Kolb, Bryan; Kovalchuk, Olga

2004-01-01

Radiation exposure is known to have profound effects on the brain, leading to precursor cell dysfunction and debilitating cognitive declines [Nat. Med. 8 (2002) 955]. Although a plethora of data exist on the effects of high radiation doses, the effects of low-dose irradiation, such as ones received during repetitive diagnostic and therapeutic exposures, are still under-investigated [Am. J. Otolaryngol. 23 (2002) 215; Proc. Natl. Acad. Sci. USA 97 (2000) 889; Curr. Opin. Neurol. 16 (2003) 129]. Furthermore, most studies of the biological effects of ionizing radiation have been performed using a single acute dose, while clinically and environmentally relevant exposures occur predominantly under chronic/repetitive conditions. Here, we have used a mouse model to compare the effects of chronic/repetitive and acute low-dose radiation (LDR) exposure (0.5 Gy) to ionizing radiation on the brain in vivo. We examined the LDR effects on p42/44 MAPK (ERK1/ERK2), CaMKII, and AKT signaling-the interconnected pathways that have been previously shown to be crucial for neuronal survival upon irradiation. We report perturbations in ERK1/2, AKT, and CREB upon acute and chronic/repetitive low-dose exposure in the hippocampus and frontal cortex of mice. These studies were paralleled by the analysis of radiation effects on neurogenesis and cellular proliferation. Repetitive exposure had a much more pronounced effect on cellular signaling and neurogenesis than acute exposure. These results suggest that studies of single acute exposures might be limited in terms of their predictive value. We also present the first evidence of sex differences in radiation-induced signaling in the hippocampus and frontal cortex. We show the role of estrogens in brain radiation responses and discuss the implications of the observed changes

Brain Aquaporin-4 in Experimental Acute Liver Failure

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Rama Rao, Kakulavarapu V.; Jayakumar, Arumugam R.; Tong, Xiaoying; Curtis, Kevin M.; Norenberg, Michael D.

2016-01-01

Intracranial hypertension due to brain edema and associated astrocyte swelling is a potentially lethal complication of acute liver failure (ALF). Mechanisms of edema formation are not well understood but elevated levels of blood and brain ammonia and its byproduct glutamine have been implicated in this process. We examined mRNA and protein expression of the water channel protein aquaporin-4 (AQP4) in cerebral cortex in a rat model of ALF induced by the hepatotoxin thioacetamide. Rats with ALF showed increased AQP4 protein in the plasma membrane (PM). Total tissue levels of AQP4 protein and mRNA levels were not altered indicating that increased AQP4 is not transcriptionally mediated but is likely due to a conformational change in the protein, i.e. a more stable anchoring of AQP4 to the PM and/or interference with its degradation. By immunohistochemistry there was an increase in AQP4 immunoreactivity in the PM of perivascular astrocytes in ALF. Rats with ALF showed increased levels of α-syntrophin, a protein involved in the anchoring of AQP4 to perivascular astrocytic end-feet. Increased AQP4 and α-syntrophin levels were inhibited by L-histidine, an inhibitor of glutamine transport into mitochondria, suggesting a role for glutamine in the increase of PM levels of AQP4. These results indicate that increased AQP4 PM levels in perivascular astrocytic end-feet are likely critical to the development of brain edema in ALF. PMID:20720509

Alterations in blood-brain barrier function following acute hypertension: comparison of the blood-to-brain transfer of horseradish peroxidase with that of alpha-aminisobutyric acid

International Nuclear Information System (INIS)

Ellison, M.D.B.

1985-01-01

The blood-brain barrier (BBB) selectively restricts the blood-to-brain passage of many solutes owing to unique properties of cerebrovascular endothelial cell membranes. To date, experimental study of the BBB has been accomplished primarily through the use of two different methodological approaches. Morphological studies have mostly employed large molecular weight (MW) tracers to detect morphological alterations underlying increased permeability. Physiological studies, employing smaller, more physiologic tracers have successfully described, quantitatively, certain functional aspects of blood-to-brain transfer. The current work attempts to merge these two approaches and to consider barrier function/dysfunction from both a morphological and a functional perspective. Specifically, the study compares in rats, following acute hypertension, the cerebrovascular passage of 14 C-alpha-aminoisobutyric acid (AIB) and that of horseradish peroxidase (HRP). The blood-to-brain passage of AIB and HRP were compared following acute hypertension, with regard to both the distributions of the tracer extravasation patterns and the magnitude of tracer extravasation. The results of this study suggest that traditional morphological barrier studies alone do not reveal all aspects of altered barrier status and that multiple mechanisms underlying increased BBB permeability may operate simultaneously during BBB dysfunction

Inflammatory responses are not sufficient to cause delayed neuronal death in ATP-induced acute brain injury.

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Hey-Kyeong Jeong

Full Text Available BACKGROUND: Brain inflammation is accompanied by brain injury. However, it is controversial whether inflammatory responses are harmful or beneficial to neurons. Because many studies have been performed using cultured microglia and neurons, it has not been possible to assess the influence of multiple cell types and diverse factors that dynamically and continuously change in vivo. Furthermore, behavior of microglia and other inflammatory cells could have been overlooked since most studies have focused on neuronal death. Therefore, it is essential to analyze the precise roles of microglia and brain inflammation in the injured brain, and determine their contribution to neuronal damage in vivo from the onset of injury. METHODS AND FINDINGS: Acute neuronal damage was induced by stereotaxic injection of ATP into the substantia nigra pars compacta (SNpc and the cortex of the rat brain. Inflammatory responses and their effects on neuronal damage were investigated by immunohistochemistry, electron microscopy, quantitative RT-PCR, and stereological counting, etc. ATP acutely caused death of microglia as well as neurons in a similar area within 3 h. We defined as the core region the area where both TH(+ and Iba-1(+ cells acutely died, and as the penumbra the area surrounding the core where Iba-1(+ cells showed activated morphology. In the penumbra region, morphologically activated microglia arranged around the injury sites. Monocytes filled the damaged core after neurons and microglia died. Interestingly, neither activated microglia nor monocytes expressed iNOS, a major neurotoxic inflammatory mediator. Monocytes rather expressed CD68, a marker of phagocytic activity. Importantly, the total number of dopaminergic neurons in the SNpc at 3 h (∼80% of that in the contralateral side did not decrease further at 7 d. Similarly, in the cortex, ATP-induced neuron-damage area detected at 3 h did not increase for up to 7 d. CONCLUSIONS: Different cellular

CT manifestation of diffuse brain injury in cases of serious acute subdural hematoma

Energy Technology Data Exchange (ETDEWEB)

Nikaido, Yuji; Shimomura, Takahide; Fujita, Toyohisa; Hirabayashi, Hidehiro; Utsumi, Shozaburo

1987-04-01

Eighty-two adult cases of serious acute subdural hematoma (SDH) of Glasgow Coma Scale 9 or more severe (50 operated-on and 32 non-operated-on cases) were selected in order to study the relation between CT findings at the acute stage and the prognosis of SDH. The CT findings were analyzed in the following respects: size of SDH, midline shift, manifestation of perimesencephalic cisterns, and presence or absence of diffuse hemispheric swelling, diffuse cerebral swelling, subarachnoid hemorrhage, intraventricular hemorrhage, epidural hematoma, hemorrhagic contusion, and dilatation of the contralateral temporal horn. As a result, the most important prognostic signs were found to be: (1) diffuse hemispheric swelling, (2) diffuse cerebral swelling, (3) subarachnoid hemorrhage of the basal-cistern type, (4) intraventricular hemorrhage, (5) deep-seated contusion, (6) complete effacement of the perimesencephalic cisterns, and (7) dilatation of the contralateral temporal horn. These findings, except for the last item, which indicates the final phase of tentorial herniation, were regarded as various patterns of the CT manifestation of diffuse brain injury; the positively associated diffuse brain injury seemed to determine the prognosis of SDH.

Cortisol evaluation during the acute phase of traumatic brain injury-A prospective study.

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Bensalah, Meriem; Donaldson, Malcolm; Aribi, Yamina; Iabassen, Malek; Cherfi, Lyes; Nebbal, Mustapha; Medjaher, Meriem; Haffaf, ElMehdi; Abdennebi, Benaissa; Guenane, Kamel; Djermane, Adel; Kemali, Zahra; OuldKablia, Samia

2018-05-01

Biochemical diagnosis of adrenal insufficiency (AI) is difficult in the context of traumatic brain injury (TBI). To assess the frequency and predictive factors of AI in victims of TBI from Algiers. Between November 2009 and December 2013, TBI victims had a single 8-9 am serum cortisol measurement during the acute postinjury period (0-7 days). AI was defined according to basal cortisol levels of 83, 276 and 414 nmol/L. Variables studied were TBI severity according to Glasgow coma scale, duration of intubation and coma, pupillary status, hypotension, anaemia, brain imaging findings, diabetes insipidus and medication. Insulin tolerance test was performed during the recovery phase, defining AI as peak cortisol 414 nmol/L. Hydrocortisone replacement is advised in TBI patients with morning cortisol <276 nmol/L or those <414 nmol/L with additional risk factors for AI. As acute and subsequent AI are poorly correlated, patients with moderate/severe TBI require adrenal re-evaluation during the recovery phase. © 2018 John Wiley & Sons Ltd.

Increased blood-brain transfer in a rabbit model of acute liver failure

International Nuclear Information System (INIS)

Horowitz, M.E.; Schafer, D.F.; Molnar, P.; Jones, E.A.; Blasberg, R.G.; Patlak, C.S.; Waggoner, J.; Fenstermacher, J.D.

1983-01-01

The blood-to-brain transfer of [ 14 C]alpha-aminoisobutyric acid was investigated by quantitative autoradiography in normal rabbits and rabbits with acute liver failure induced by the selective hepatotoxin galactosamine. The blood-to-brain transfer of alpha-aminoisobutyric acid was similar in control animals and animals 2 and 7 h after galactosamine injections, but was increased five- to tenfold in certain gray-matter areas of the brain in animals 11 and 18 h after galactosamine treatment. No detectable differences in white-matter uptake of [ 14 C]alpha-aminoisobutyric acid were found between the control and treated groups. The increase in alpha-aminoisobutyric acid transfer within the gray-matter areas suggested that a general or nonspecific increase in brain capillary permeability occurred in these areas. No clinical signs of early hepatic encephalopathy were observed in the treated rabbits, except for 1 animal from the 18-h postgalactosamine group. Thus, enhanced blood-brain transfer of alpha-aminoisobutyric acid preceded the development of overt hepatic encephalopathy. The distribution of radioactivity after the intravenous administration of [ 14 C]galactosamine showed that virtually none of the hepatotoxin localized in the brain, suggesting that the drug itself does not have a direct effect upon the blood-brain barrier or the brain. The increased uptake of alpha-aminoisobutyric acid at 11 and 18 h implies that the transfer of other solutes would also be enhanced, that central nervous system homeostasis would be compromised, and that the resulting changes in brain fluid composition could contribute to or cause hepatic encephalopathy

NeuroSPECT assessment of ischemic penumbra in acute brain infarct: control of intra-arterial thrombolysis

International Nuclear Information System (INIS)

Mena, F.J.; Mena, I.; Contreras, I.; Soto, F.; Ducci, H.; Fruns, M.

2002-01-01

Introduction: Brain infarct is the most common cause of incapacity in adults, the second cause of dementia and the 2nd or 3rd cause of death. Acute brain infarct is a medical emergency potentially reversible if treated with thrombolysis in the first hours of evolution. Thrombolysis is now an approved and efficacious method of treatment for acute ischemic stroke. During the first 3 hours of evolution, intravenous administration of plasminogen activator (tPA) can be performed. The window of time of treatment is expanded to 6 hours with the intra-arterial super selective route for thrombolysis. Aim: The aim of this study was to define levels of reversible ischemia (penumbra) demonstrated by statistically evaluated HMPAO Tc99m NeuroSPECT performed before and after intra-arterial thrombolysis in the treatment of acute infarct. Materials and Methods: 21 patients were treated during the first 6 hours of evolution of an acute ischemic stroke with the following protocol. 1) Admission, and complete neurological evaluation. 2) Brain CT scan to rule hemorrhage or established infarct. 3) I.V injection of 1100MBq Tc99m HMPAO (Ceretec tm) 4) Conventional cerebral angiography and intra-arterial thrombolysis and/or angioplasty/stenting if necessary. 5) NeuroSPECT assessment of ischemic penumbra. 6) Control at 24 hrs with NeuroSPECT. NeuroSPECT image acquisition is performed immediately following arterial thrombolysis with a dual Head Camera, SHR collimators and conventional protocol. Image processing was performed using the Segami Software, as previously reported in Alasbimn Journal2 (7): April 2000. http://www.alasbimnjournal.cl. The analysis consists of 1) Tallairach brain volume normalization. 2) Voxel by voxel comparison of the individual brain cortex uptake normalized to the maximum in the cortex with a normal database of 24 age-matched controls. Results: The results are expressed in standard deviations (S.D.) below the normal mean. Normal mean is 72% + 6. Only voxels between

Brain energy metabolism is activated after acute and chronic administration of fenproporex in young rats.

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Rezin, Gislaine T; Jeremias, Isabela C; Ferreira, Gabriela K; Cardoso, Mariane R; Morais, Meline O S; Gomes, Lara M; Martinello, Otaviana B; Valvassori, Samira S; Quevedo, João; Streck, Emilio L

2011-12-01

Obesity is a chronic disease of multiple etiologies, including genetic, metabolic, environmental, social, and other factors. Pharmaceutical strategies in the treatment of obesity include drugs that regulate food intake, thermo genesis, fat absorption, and fat metabolism. Fenproporex is the second most commonly consumed amphetamine-based anorectic worldwide; this drug is rapidly converted in vivo into amphetamine. Studies suggest that amphetamine induces neurotoxicity through generation of free radicals and mitochondrial apoptotic pathway by cytochrome c release, accompanied by a decrease of mitochondrial membrane potential. Mitochondria are intracellular organelles that play a crucial role in ATP production. Thus, in the present study we evaluated the activities of some enzymes of Krebs cycle, mitochondrial respiratory chain complexes and creatine kinase in the brain of young rats submitted to acute and chronic administration of fenproporex. In the acute administration, the animals received a single injection of fenproporex (6.25, 12.5 or 25 mg/kg i.p.) or tween. In the chronic administration, the animals received a single injection daily for 14 days of fenproporex (6.25, 12.5 or 25 mg/Kg i.p.). Two hours after the last injection, the rats were sacrificed by decapitation and the brain was removed for evaluation of biochemical parameters. Our results showed that the activities of citrate synthase, malate dehydrogenase and succinate dehydrogenase were increased by acute and chronic administration of fenproporex. Complexes I, II, II-III and IV and creatine kinase activities were also increased after acute and chronic administration of the drug. Our results are consistent with others reports that showed that some psychostimulant drugs increased brain energy metabolism in young rats. Copyright © 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

Distribution of trans-resveratrol and its metabolites after acute or sustained administration in mouse heart, brain, and liver.

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Menet, Marie-Claude; Baron, Stephanie; Taghi, Meryam; Diestra, Remi; Dargère, Delphine; Laprévote, Olivier; Nivet-Antoine, Valérie; Beaudeux, Jean-Louis; Bédarida, Tatiana; Cottart, Charles-Henry

2017-08-01

Trans-resveratrol is widely studied for its potentially beneficial effects on numerous disorders. It is rapidly metabolized and its metabolites can exhibit biological activity. The present study aimed to investigate whether acute or sustained trans-resveratrol administration impacted on the distribution of trans-resveratrol and its metabolites in brain, heart, and liver. We used ultra-HPLC quadrupole-TOF (UHPLC-Q-TOF) in a full-scan mode to identify and assess large numbers of resveratrol metabolites. For acute intake, mice were overfed with a single dose of trans-resveratrol (150 mg/kg) and organs were collected after 30 and 60 min. For sustained intake, trans-resveratrol was given in the chow (0.04% w/w corresponding to 40 mg/kg/day), and plasma and the organs were collected after 3 months of this resveratrol diet. We found that trans-resveratrol-3-O-glucuronide and resveratrol-3-sulfate were the main metabolites found after acute intake, and free trans-resveratrol (in the brain and heart) and dihydroresveratrol derivatives were found after sustained administration CONCLUSIONS: Our results show notable differences between acute and sustained administration of trans-resveratrol and distribution of trans-resveratrol and its metabolites in mouse heart, brain, and liver. The results suggest a strategy for development of galenic forms of resveratrol. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Traumatic brain injury and post-acute decline: what role does environmental enrichment play? A scoping review

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Diana eFrasca

2013-04-01

Full Text Available Objectives. While a number of studies provide evidence of neural and cognitive decline in traumatic brain injury (TBI survivors during the post-acute stages of injury, there is a dearth of research on the possible mechanisms underlying this decline. The purposes of this paper, therefore, are to (1 examine evidence that environmental enrichment (EE can influence long-term outcome following TBI, and (2 examine the nature of post-acute environments, whether they vary in degree of EE, and what impact these variations have on outcomes.Methods. We conducted a scoping review to identify studies on EE in animals and humans, and post-discharge experiences that relate to barriers to recovery.Results. Ninety-six articles that met inclusion criteria demonstrated the benefits of EE on brain and behaviour in healthy and brain-injured animals and humans. Nineteen papers on post-discharge experiences provided evidence that variables such as insurance coverage, financial and social support, home therapy, and transition from hospital to home, also play a vital role in regaining independence. Conclusion. There is evidence to suggest that lack of EE, whether from lack of resources or limited ability to engage in such environments, may play a role in post-recovery cognitive and neural decline. Maximizing EE in the post-acute stages of TBI may improve long-term outcomes for the individual, their family and society.

Altered intrinsic brain activities in patients with acute eye pain using amplitude of low-frequency fluctuation: a resting-state fMRI study

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Pan Z

2018-01-01

Full Text Available Zhi-Ming Pan,1 Hai-Jun Li,1 Jing Bao,1 Nan Jiang,1 Qing Yuan,1 Shelby Freeberg,2 Pei-Wen Zhu,1 Lei Ye,1 Ming-Yang Ma,1 Xin Huang,1 Yi Shao1 1Department of Ophthalmology and Radiology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China; 2Department of Ophthalmology, University of Florida, Gainesville, FL, USA Objective: Many previous studies have reported that pain symptoms can lead to significant brain function and anatomical changes, whereas the intrinsic brain activity changes in acute eye pain (EP patients remain unknown. Using the amplitude of low-frequency fluctuation (ALFF method, this study aimed to evaluate the spontaneous brain activity alterations and their relationships with clinical features in acute EP patients.Participants and methods: A total of 20 patients with EP (15 males and 5 females and 20 healthy controls (HCs; 15 males and 5 females closely matched in age, sex, and education underwent resting-state functional magnetic resonance imaging scans. The ALFF method was applied to assess spontaneous brain activity changes. The ALFF values of the EP patients were distinguished from those of the HCs using a receiver operating characteristic curve. Pearson’s correlation analysis was used to investigate the relationships between the mean ALFF signal values from many brain regions and the clinical features in EP patients.Results: Compared with the HCs, acute EP patients had significantly lower ALFF in the left and right precentral/postcentral gyrus and left precuneus. In contrast, acute EP patients showed higher ALFF values in the right and left parahippocampal gyri and left caudate. However, no relationship was observed between the mean ALFF signal values from the different areas and clinical manifestations in the acute EP patients.Conclusion: We demonstrated that acute EP patients showed abnormal intrinsic brain activities in the precentral/postcentral gyrus and limbic system

Acute but not chronic activation of brain glucagon-like peptide-1 receptors enhances glucose-stimulated insulin secretion in mice.

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Tudurí, E; Beiroa, D; Porteiro, B; López, M; Diéguez, C; Nogueiras, R

2015-08-01

To investigate the role of brain glucagon-like peptide-1 (GLP-1) in pancreatic β-cell function. To determine the role of brain GLP-1 receptor (GLP-1R) on β-cell function, we administered intracerebroventricular (i.c.v.) infusions of GLP-1 or the specific GLP-1 antagonist exendin-9 (Ex-9), in both an acute and a chronic setting. We observed that acute i.c.v. GLP-1 infusion potentiates glucose-stimulated insulin secretion (GSIS) and improves glucose tolerance, whereas central GLP-1R blockade with Ex-9 impaired glucose excursion after a glucose load. Sustained activation of central nervous system GLP-1R, however, did not produce any effect on either GSIS or glucose tolerance. Similarly, ex vivo GSIS performed in islets from mice chronically infused with i.c.v. GLP-1 resulted in no differences compared with controls. In addition, in mice fed a high-fat diet we observed that acute i.c.v. GLP-1 infusion improved glucose tolerance without changes in GSIS, while chronic GLP-1R activation had no effect on glucose homeostasis. Our results indicate that, under non-clamped conditions, brain GLP-1 plays a functional neuroendocrine role in the acute regulation of glucose homeostasis in both lean and obese rodents. © 2015 John Wiley & Sons Ltd.

Excitatory amino acid neurotoxicity and modulation of glutamate receptor expression in organotypic brain slice cultures

DEFF Research Database (Denmark)

Zimmer, J; Kristensen, Bjarne Winther; Jakobsen, B

2000-01-01

Using organotypic slice cultures of hippocampus and cortex-striatum from newborn to 7 day old rats, we are currently studying the excitotoxic effects of kainic acid (KA), AMPA and NMDA and the neuroprotective effects of glutamate receptor blockers, like NBQX. For detection and quantitation...

Identification of Reversible Disruption of the Human Blood-Brain Barrier Following Acute Ischemia.

Science.gov (United States)

Simpkins, Alexis N; Dias, Christian; Leigh, Richard

2016-09-01

Animal models of acute cerebral ischemia have demonstrated that diffuse blood-brain barrier (BBB) disruption can be reversible after early reperfusion. However, irreversible, focal BBB disruption in humans is associated with hemorrhagic transformation in patients receiving intravenous thrombolytic therapy. The goal of this study was to use a magnetic resonance imaging biomarker of BBB permeability to differentiate these 2 forms of BBB disruption. Acute stroke patients imaged with magnetic resonance imaging before, 2 hours after, and 24 hours after treatment with intravenous tissue-type plasminogen activator were included. The average BBB permeability of the acute ischemic region before and 2 hours after treatment was calculated using a T2* perfusion-weighted source images. Change in average permeability was compared with percent reperfusion using linear regression. Focal regions of maximal BBB permeability from the pretreatment magnetic resonance imaging were compared with the occurrence of parenchymal hematoma (PH) formation on the 24-hour magnetic resonance imaging scan using logistic regression. Signals indicating reversible BBB permeability were detected in 18/36 patients. Change in average BBB permeability correlated inversely with percent reperfusion (P=0.006), indicating that early reperfusion is associated with decreased BBB permeability, whereas sustained ischemia is associated with increased BBB disruption. Focal regions of maximal BBB permeability were significantly associated with subsequent formation of PH (P=0.013). This study demonstrates that diffuse, mild BBB disruption in the acutely ischemic human brain is reversible with reperfusion. This study also confirms prior findings that focal severe BBB disruption confers an increased risk of hemorrhagic transformation in patients treated with intravenous tissue-type plasminogen activator. © 2016 American Heart Association, Inc.

"The Most Famous Brain in the World" Performance and Pedagogy on an Amnesiac's Brain

Science.gov (United States)

Sweaney, Katherine W.

2012-01-01

Project H.M. was just the sort of thing one might expect the Internet to latch onto: it was a live streaming video of a frozen human brain being slowly sliced apart. Users who clicked the link on Twitter or Facebook between the 2nd and 4th of December 2009 were immediately confronted with a close-up shot of the brain's interior, which was…

Brain temperature measured by 1H-magnetic resonance spectroscopy in acute and subacute carbon monoxide poisoning

International Nuclear Information System (INIS)

Fujiwara, Shunrou; Nishimoto, Hideaki; Murakami, Toshiyuki; Ogawa, Akira; Ogasawara, Kuniaki; Yoshioka, Yoshichika; Matsuda, Tsuyoshi; Beppu, Takaaki

2016-01-01

Brain temperature (BT) is associated with the balance between cerebral blood flow and metabolism according to the ''heat-removal'' theory. The present study investigated whether BT is abnormally altered in acute and subacute CO-poisoned patients by using 1 H-magnetic resonance spectroscopy (MRS). Eight adult CO-poisoned patients underwent 3-T magnetic resonance imaging in the acute and subacute phases after CO exposure. MRS was performed on deep cerebral white matter in the centrum semiovale, and MRS-based BT was estimated by the chemical shift difference between water and the N-acetyl aspartate signal. We defined the mean BT + 1.96 standard deviations of the BT in 15 healthy controls as the cutoff value for abnormal BT increases (p < 0.05) in CO-poisoned patients. BT of CO-poisoned patients in both the acute and subacute phases was significantly higher than that of the healthy control group. However, BT in the subacute phase was significantly lower than in the acute phase. On the other hand, no significant difference in body temperature was observed between acute and subacute CO-poisoned patients. BT weakly correlated with body temperature, but this correlation was not statistically significant (rho = 0.304, p = 0.2909). The present results suggest that BT in CO-poisoned patients is abnormally high in the acute phase and remains abnormal in the subacute phase. BT alteration in these patients may be associated with brain perfusion and metabolism rather than other factors such as systemic inflammation and body temperature. (orig.)

Muscarinic agonists and phorbol esters increase tyrosine phosphorylation of a 40-kilodalton protein in hippocampal slices

International Nuclear Information System (INIS)

Stratton, K.R.; Worley, P.F.; Huganir, R.L.; Baraban, J.M.

1989-01-01

The authors have used the hippocampal slice preparation to investigate the regulation of protein tyrosine phosphorylation in brain. After pharmacological treatment of intact slices, proteins were separated by electrophoresis, and levels of protein tyrosine phosphorylation were assessed by immunoblotting with specific anti-phosphotyrosine antibodies. Phorbol esters, activators of the serine- and threonine-phosphorylating enzyme protein kinase C, selectively increase tyrosine phosphorylation of a soluble protein with an apparent molecular mass of approximately 40 kilodaltons. Muscarinic agonists such as carbachol and oxotremorine M that strongly activate the inositol phospholipid system also increase tyrosine phosphorylation of this protein. Neurotransmitter activation of the inositol phospholipid system and protein kinase C appears to trigger a cascade leading to increased tyrosine phosphorylation

Cognitive Impairment and Whole Brain Diffusion in Patients with Neuromyelitis Optica after Acute Relapse

Science.gov (United States)

He, Diane; Wu, Qizhu; Chen, Xiuying; Zhao, Daidi; Gong, Qiyong; Zhou, Hongyu

2011-01-01

The objective of this study investigated cognitive impairments and their correlations with fractional anisotropy (FA) and mean diffusivity (MD) in patients with neuromyelitis optica (NMO) without visible lesions on conventional brain MRI during acute relapse. Twenty one patients with NMO and 21 normal control subjects received several cognitive…

Middle cerebral artery thrombosis: acute blood-brain barrier consequences

Energy Technology Data Exchange (ETDEWEB)

Dietrich, W.D.; Prado, R.; Watson, B.D.; Nakayama, H.

1988-07-01

The effect of middle cerebral artery (MCA) thrombosis on the integrity of the blood-brain barrier (BBB) was studied in rats using horseradish peroxidase (HRP). Endothelial injury with subsequent platelet thrombosis was produced by means of a rose bengal-sensitized photochemical reaction, facilitated by irradiating the right proximal MCA segment with the focused beam of an argon laser. At 15 minutes following thrombosis formation, diffuse leakage of HRP was observed bilaterally within cortical and subcortical brain areas. Peroxidase extravasation was most dense within the territory of the occluded artery including neocortical areas and dorso-lateral striatum. Contralaterally, a similar distribution was observed but with less intense HRP leakage. Ultrastructural studies demonstrated an increase in permeability to HRP within arterioles, venules and capillaries. At these sites, the vascular endothelium contained HRP-filled pinocytotic vesicles and tubular profiles. Although less intense, bilateral HRP leakage was also observed following MCA stenosis or femoral artery occlusion. Endothelial-platelet interactions at the site of vascular injury may be responsible for releasing substances or neurohumoral factors which contribute to the acute opening of the BBB.

Fetal brain volumetry through MRI volumetric reconstruction and segmentation

Science.gov (United States)

Estroff, Judy A.; Barnewolt, Carol E.; Connolly, Susan A.; Warfield, Simon K.

2013-01-01

Purpose Fetal MRI volumetry is a useful technique but it is limited by a dependency upon motion-free scans, tedious manual segmentation, and spatial inaccuracy due to thick-slice scans. An image processing pipeline that addresses these limitations was developed and tested. Materials and methods The principal sequences acquired in fetal MRI clinical practice are multiple orthogonal single-shot fast spin echo scans. State-of-the-art image processing techniques were used for inter-slice motion correction and super-resolution reconstruction of high-resolution volumetric images from these scans. The reconstructed volume images were processed with intensity non-uniformity correction and the fetal brain extracted by using supervised automated segmentation. Results Reconstruction, segmentation and volumetry of the fetal brains for a cohort of twenty-five clinically acquired fetal MRI scans was done. Performance metrics for volume reconstruction, segmentation and volumetry were determined by comparing to manual tracings in five randomly chosen cases. Finally, analysis of the fetal brain and parenchymal volumes was performed based on the gestational age of the fetuses. Conclusion The image processing pipeline developed in this study enables volume rendering and accurate fetal brain volumetry by addressing the limitations of current volumetry techniques, which include dependency on motion-free scans, manual segmentation, and inaccurate thick-slice interpolation. PMID:20625848

Protein-energy malnutrition developing after global brain ischemia induces an atypical acute-phase response and hinders expression of GAP-43.

Science.gov (United States)

Smith, Shari E; Figley, Sarah A; Schreyer, David J; Paterson, Phyllis G

2014-01-01

Protein-energy malnutrition (PEM) is a common post-stroke problem. PEM can independently induce a systemic acute-phase response, and pre-existing malnutrition can exacerbate neuroinflammation induced by brain ischemia. In contrast, the effects of PEM developing in the post-ischemic period have not been studied. Since excessive inflammation can impede brain remodeling, we investigated the effects of post-ischemic malnutrition on neuroinflammation, the acute-phase reaction, and neuroplasticity-related proteins. Male, Sprague-Dawley rats were exposed to global forebrain ischemia using the 2-vessel occlusion model or sham surgery. The sham rats were assigned to control diet (18% protein) on day 3 after surgery, whereas the rats exposed to global ischemia were assigned to either control diet or a low protein (PEM, 2% protein) diet. Post-ischemic PEM decreased growth associated protein-43, synaptophysin and synaptosomal-associated protein-25 immunofluorescence within the hippocampal CA3 mossy fiber terminals on day 21, whereas the glial response in the hippocampal CA1 and CA3 subregions was unaltered by PEM. No systemic acute-phase reaction attributable to global ischemia was detected in control diet-fed rats, as reflected by serum concentrations of alpha-2-macroglobulin, alpha-1-acid glycoprotein, haptoglobin, and albumin. Acute exposure to the PEM regimen after global brain ischemia caused an atypical acute-phase response. PEM decreased the serum concentrations of albumin and haptoglobin on day 5, with the decreases sustained to day 21. Serum alpha-2-macroglobulin concentrations were significantly higher in malnourished rats on day 21. This provides the first direct evidence that PEM developing after brain ischemia exerts wide-ranging effects on mechanisms important to stroke recovery.

Adrenergic pathways in dopamine modulation of K+ transport in cortex slices after low dose X-Rays

International Nuclear Information System (INIS)

Kulikova, I.A.; Dvoretsky, A.I.

1997-01-01

Using the method of surviving brain cortex slices it has been shown that prolonged whole body acute or chronic 25 cGy X-irradiation (1 cGy/day at dose rate of 2.22 mGy/min) essentially modified dopamine (DA) modulating influence upon Na, K-pump in nervous tissue. Obtained results pointed to that normally DA had the defined biphasic effect upon active K + transport with lower level activation (by 24.0 %) and higher level inhibition (by 42.1 %). The patterns of the Na,K-pump reaction to DA was not changed after irradiation, but percentage of the total DA suppression was increased by 15.1 % in average after single X-ray exposure and by 34.5 % after chronic one. The decisive role of β-adrenergic mechanisms in realization of postirradiation interaction between systems of catecholamine and active K + transfer across neuronal membrane has been determined. Experimental data obtained with the use of 10 μM phentolamine and 10 μM propranolol, respectively α- and β-adrenergic antagonists, supported that metabolic DA effect was mediated via α-AR normally, and via β-AR after low dose-rate irradiation. (authors)

Effects of normobaric versus hyperbaric oxygen on cell injury induced by oxygen and glucose deprivation in acute brain slices

OpenAIRE

Laurent Chazalviel; Jean-Eric Blatteau; Nicolas Vallée; Jean-Jacques Risso; Stéphane Besnard; Jacques H Abraini

2016-01-01

Normobaric oxygen (NBO) and hyperbaric oxygen (HBO) are emerging as a possible co-treatment of acute ischemic stroke. Both have been shown to reduce infarct volume, to improve neurologic outcome, to promote endogenous tissue plasminogen activator-induced thrombolysis and cerebral blood flow, and to improve tissue oxygenation through oxygen diffusion in the ischemic areas, thereby questioning the interest of HBO compared to NBO. In the present study, in order to investigate and compare the oxy...

How acute total sleep loss affects the attending brain: a meta-analysis of neuroimaging studies.

Science.gov (United States)

Ma, Ning; Dinges, David F; Basner, Mathias; Rao, Hengyi

2015-02-01

Attention is a cognitive domain that can be severely affected by sleep deprivation. Previous neuroimaging studies have used different attention paradigms and reported both increased and reduced brain activation after sleep deprivation. However, due to large variability in sleep deprivation protocols, task paradigms, experimental designs, characteristics of subject populations, and imaging techniques, there is no consensus regarding the effects of sleep loss on the attending brain. The aim of this meta-analysis was to identify brain activations that are commonly altered by acute total sleep deprivation across different attention tasks. Coordinate-based meta-analysis of neuroimaging studies of performance on attention tasks during experimental sleep deprivation. The current version of the activation likelihood estimation (ALE) approach was used for meta-analysis. The authors searched published articles and identified 11 sleep deprivation neuroimaging studies using different attention tasks with a total of 185 participants, equaling 81 foci for ALE analysis. The meta-analysis revealed significantly reduced brain activation in multiple regions following sleep deprivation compared to rested wakefulness, including bilateral intraparietal sulcus, bilateral insula, right prefrontal cortex, medial frontal cortex, and right parahippocampal gyrus. Increased activation was found only in bilateral thalamus after sleep deprivation compared to rested wakefulness. Acute total sleep deprivation decreases brain activation in the fronto-parietal attention network (prefrontal cortex and intraparietal sulcus) and in the salience network (insula and medial frontal cortex). Increased thalamic activation after sleep deprivation may reflect a complex interaction between the de-arousing effects of sleep loss and the arousing effects of task performance on thalamic activity. © 2015 Associated Professional Sleep Societies, LLC.

Maintenance of drug metabolism and transport functions in human precision-cut liver slices during prolonged incubation for 5 days

NARCIS (Netherlands)

Starokozhko, Viktoriia; Vatakuti, Suresh; Schievink, Bauke; Merema, Marjolijn T.; Asplund, Annika; Synnergren, Jane; Aspegren, Anders; Groothuis, Geny M. M.

Human precision-cut liver slices (hPCLS) are a valuable ex vivo model that can be used in acute toxicity studies. However, a rapid decline in metabolic enzyme activity limits their use in studies that require a prolonged xenobiotic exposure. The aim of the study was to extend the viability and

BAD and KATP channels regulate neuron excitability and epileptiform activity.

Science.gov (United States)

Martínez-François, Juan Ramón; Fernández-Agüera, María Carmen; Nathwani, Nidhi; Lahmann, Carolina; Burnham, Veronica L; Danial, Nika N; Yellen, Gary

2018-01-25

Brain metabolism can profoundly influence neuronal excitability. Mice with genetic deletion or alteration of Bad ( B CL-2 a gonist of cell d eath) exhibit altered brain-cell fuel metabolism, accompanied by resistance to acutely induced epileptic seizures; this seizure protection is mediated by ATP-sensitive potassium (K ATP ) channels. Here we investigated the effect of BAD manipulation on K ATP channel activity and excitability in acute brain slices. We found that BAD's influence on neuronal K ATP channels was cell-autonomous and directly affected dentate granule neuron (DGN) excitability. To investigate the role of neuronal K ATP channels in the anticonvulsant effects of BAD, we imaged calcium during picrotoxin-induced epileptiform activity in entorhinal-hippocampal slices. BAD knockout reduced epileptiform activity, and this effect was lost upon knockout or pharmacological inhibition of K ATP channels. Targeted BAD knockout in DGNs alone was sufficient for the antiseizure effect in slices, consistent with a 'dentate gate' function that is reinforced by increased K ATP channel activity. © 2018, Martínez-François et al.

Resting State Functional Connectivity in Mild Traumatic Brain Injury at the Acute Stage: Independent Component and Seed-Based Analyses

Science.gov (United States)

Iraji, Armin; Benson, Randall R.; Welch, Robert D.; O'Neil, Brian J.; Woodard, John L.; Imran Ayaz, Syed; Kulek, Andrew; Mika, Valerie; Medado, Patrick; Soltanian-Zadeh, Hamid; Liu, Tianming; Haacke, E. Mark

2015-01-01

Abstract Mild traumatic brain injury (mTBI) accounts for more than 1 million emergency visits each year. Most of the injured stay in the emergency department for a few hours and are discharged home without a specific follow-up plan because of their negative clinical structural imaging. Advanced magnetic resonance imaging (MRI), particularly functional MRI (fMRI), has been reported as being sensitive to functional disturbances after brain injury. In this study, a cohort of 12 patients with mTBI were prospectively recruited from the emergency department of our local Level-1 trauma center for an advanced MRI scan at the acute stage. Sixteen age- and sex-matched controls were also recruited for comparison. Both group-based and individual-based independent component analysis of resting-state fMRI (rsfMRI) demonstrated reduced functional connectivity in both posterior cingulate cortex (PCC) and precuneus regions in comparison with controls, which is part of the default mode network (DMN). Further seed-based analysis confirmed reduced functional connectivity in these two regions and also demonstrated increased connectivity between these regions and other regions of the brain in mTBI. Seed-based analysis using the thalamus, hippocampus, and amygdala regions further demonstrated increased functional connectivity between these regions and other regions of the brain, particularly in the frontal lobe, in mTBI. Our data demonstrate alterations of multiple brain networks at the resting state, particularly increased functional connectivity in the frontal lobe, in response to brain concussion at the acute stage. Resting-state functional connectivity of the DMN could serve as a potential biomarker for improved detection of mTBI in the acute setting. PMID:25285363

Acute alcohol intoxication in patients with mild traumatic brain injury : Characteristics, recovery, and outcome

NARCIS (Netherlands)

Scheenen, Myrthe E.; de Koning, Myrthe E.; van der Horn, Harm J.; Roks, C.M.A.A.; Yilmaz, Tansel; van der Naalt, Joukje; Spikman, Jacoba M.

2016-01-01

A substantial number of patients (30% to 50%) sustains a mild traumatic brain injury (mTBI) while they are under the influence of alcohol. An acute alcohol intoxication (AAI) at the time of injury has been subject of research in severe TBI, but little is known about the relation between AAI and

Acute Alcohol Intoxication in Patients with Mild Traumatic Brain Injury : Characteristics, Recovery, and Outcome

NARCIS (Netherlands)

Scheenen, Myrthe E.; de Koning, Myrthe E.; van der Horn, Harm; Roks, Gerwin; Yilmaz, Tansel; van der Naalt, Joukje; Spikman, Jacoba M.

2016-01-01

A substantial number of patients (30% to 50%) sustains a mild traumatic brain injury (mTBI) while they are under the influence of alcohol. An acute alcohol intoxication (AAI) at the time of injury has been subject of research in severe TBI, but little is known about the relation between AAI and

Radiation sterilization and identification of gizzard slices

International Nuclear Information System (INIS)

Zhu, S.; Fu, C.; Jiang, W.; Yao, D.; Zhao, K.; Zhang, Y.

1998-01-01

An orthogonal test of 4 factors of radiation dose, storage temperature, storage time, and sanitation of cutting places was carried out to optimize the conditions for disinfection of gizzard slices. In the optimized condition, both the sanitary quality and the shelf-life of gizzard slices were improved. To identify irradiated gizzard slices, the sensory change, and the levels of water-soluble nitrogen, amino acid, total volatile basic nitrogen, peroxide value, vitamin C consumption and KMnO 4 consumption were determinated. No significant change was observed except for the color which was light brown on the surface of irradiated slices

Protein synthesis in the rat brain: a comparative in vivo and in vitro study in immature and adult animals

International Nuclear Information System (INIS)

Shahbazian, F.M.

1985-01-01

Rates of protein synthesis of CNS and other organs were compared in immature and adult rats by in vivo and slice techniques with administration of flooding doses of labeled precursor. The relationship between synthesis and brain region, cell type, subcellular fraction, or MW was examined. Incorporation of [ 14 C]valine into protein of CNS regions in vivo was about 1.2% per hour for immature rats and 0.6% for adults. For slices, the rates decreased significantly more in adults. In adult organs, the highest synthesis rate in vivo was found in liver (2.2% per hour) followed by kidney, spleen, lung, heart, brain, and muscle (0.5% per hour). In immature animals synthesis was highest in liver and spleen (2.5% per hour) and lowest in muscle (0.9% per hour). Slices all showed lower rates than in vivo, especially in adults. In vivo, protein synthesis rates of immature neurons and astrocytes and adult neurons exceeded those of whole brain, while that in adult astrocytes was the same. These results demonstrate a developmental difference of protein synthesis (about double in immature animals) in all brain cells, cell fractions and most brain protein. Similarly the decreased synthesis in brain slices - especially in adults, affects most proteins and structural elements

Stress hormonal changes in the brain and plasma after acute noise exposure in mice.

Science.gov (United States)

Jin, Sang Gyun; Kim, Min Jung; Park, So Young; Park, Shi Nae

2017-06-01

To investigate the effects of acute noise stress on two amine stress hormones, norepinephrine (NE) and 5-hydroxyindoleacetic acid (5-HIAA) in the brain and plasma of mice after noise exposure. Mice were grouped into the control and noise groups. Mice in the noise group were exposed to white noise of 110dB sound pressure level for 60min. Auditory brainstem response thresholds, distortion product otoacoustic emissions, the organ of Corti grading scores, western blots of NE/5-HIAA in the whole brain and hippocampus, and the plasma levels of NE/5-HIAA were compared between the two groups. Significant hearing loss and cochlear damage were demonstrated in the noise group. NE and 5-HIAA in the hippocampus were elevated in the noise group (p=0.019/0.022 for NE/5-HIAA vs. the control). Plasma levels of NE and 5-HIAA were not statistically different between the groups (p=0.052/0.671 for NE/5-HIAA). Hearing loss with outer hair cell dysfunction and morphological changes of the organ of Corti after noise exposure in C57BL/6 mice proved the reliability of our animal model as an acute noise stress model. NE and 5-HIAA are suggested to be the potential biomarkers for acute noise stress in the hippocampus. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Slice hyperholomorphic Schur analysis

CERN Document Server

Alpay, Daniel; Sabadini, Irene

2016-01-01

This book defines and examines the counterpart of Schur functions and Schur analysis in the slice hyperholomorphic setting. It is organized into three parts: the first introduces readers to classical Schur analysis, while the second offers background material on quaternions, slice hyperholomorphic functions, and quaternionic functional analysis. The third part represents the core of the book and explores quaternionic Schur analysis and its various applications. The book includes previously unpublished results and provides the basis for new directions of research.

Abnormal brain MRI in a case of acute ataxia as the only sign of abdominal neuroblastoma

International Nuclear Information System (INIS)

Molla Mohammadi, M.; Karimzadeh, P.; Khatami, A.; Jadali, F.

2010-01-01

Ataxia is a movement disorder that may manifest an acute, intermittent, non progressive or chronic progressive course. Ataxia alone is rare as a para neoplastic sign, especially if it is due to neuroblastoma (abdominal or chest). We report an abdominal neuroblastoma in a two-year-old girl presenting with only acute ataxia and abnormal neuroimaging. Brain MRI showed abnormal signal finding in the medulla, pons, cortico spinal tract and the periventricular space. In the abdominal CT, a mass was detected in the right adrenal gland with calcification and the histopathologic examination re-vealed neuroblastoma. We suggest in children with acute ataxia, with or without opalescence-myoclonus, neuroblastoma should be considered.

The mitochondrial toxin, 3-nitropropionic acid, induces extracellular Zn2+ accumulation in rat hippocampus slices.

Science.gov (United States)

Wei, Guo; Hough, Christopher J; Sarvey, John M

2004-11-11

3-nitropropionic acid (3-NPA), a suicide inhibitor of succinate dehydrogenase (SDH; complex II), has been used to provide useful experimental models of Huntington's disease (HD) and "chemical hypoxia" in rodents. The trace ion Zn2+ has been shown to cause neurodegeneration. Employing real-time Newport Green fluorescence imaging of extracellular Zn2+, we found that 3-NPA (10-100 microM) caused a concentration-dependent increase in the concentration of extracellular Zn2+ ([Zn2+]o) in acute rat hippocampus slices. This increase in [Zn2+]o was abolished by 10 mM CaEDTA. The increase of [Zn2+]o was also accompanied by a rapid increase of cytoplasmic-free Zn2+ concentration ([Zn2+]i). The induction of Zn2+ release by 3-MPA in hippocampus slices points to a potential mechanism by which 3-NPA might induce neurodegeneration.

Brain temperature measured by {sup 1}H-magnetic resonance spectroscopy in acute and subacute carbon monoxide poisoning

Energy Technology Data Exchange (ETDEWEB)

Fujiwara, Shunrou; Nishimoto, Hideaki; Murakami, Toshiyuki; Ogawa, Akira; Ogasawara, Kuniaki [Iwate Medical University, Department of Neurosurgery, Morioka, Iwate (Japan); Yoshioka, Yoshichika [Osaka University, Laboratory of Biofunctional Imaging, WPI Immunology Frontier Research Center, Osaka (Japan); Matsuda, Tsuyoshi [MR Applications and Workflow Asia Pacific, GE Healthcare Japan, Tokyo (Japan); Beppu, Takaaki [Iwate Medical University, Department of Neurosurgery, Morioka, Iwate (Japan); Iwate Medical University, Department of Hyperbaric Medicine, Iwate (Japan)

2016-01-15

Brain temperature (BT) is associated with the balance between cerebral blood flow and metabolism according to the ''heat-removal'' theory. The present study investigated whether BT is abnormally altered in acute and subacute CO-poisoned patients by using {sup 1}H-magnetic resonance spectroscopy (MRS). Eight adult CO-poisoned patients underwent 3-T magnetic resonance imaging in the acute and subacute phases after CO exposure. MRS was performed on deep cerebral white matter in the centrum semiovale, and MRS-based BT was estimated by the chemical shift difference between water and the N-acetyl aspartate signal. We defined the mean BT + 1.96 standard deviations of the BT in 15 healthy controls as the cutoff value for abnormal BT increases (p < 0.05) in CO-poisoned patients. BT of CO-poisoned patients in both the acute and subacute phases was significantly higher than that of the healthy control group. However, BT in the subacute phase was significantly lower than in the acute phase. On the other hand, no significant difference in body temperature was observed between acute and subacute CO-poisoned patients. BT weakly correlated with body temperature, but this correlation was not statistically significant (rho = 0.304, p = 0.2909). The present results suggest that BT in CO-poisoned patients is abnormally high in the acute phase and remains abnormal in the subacute phase. BT alteration in these patients may be associated with brain perfusion and metabolism rather than other factors such as systemic inflammation and body temperature. (orig.)

Acute caffeine administration effect on brain activation patterns in mild cognitive impairment.

Science.gov (United States)

Haller, Sven; Montandon, Marie-Louise; Rodriguez, Cristelle; Moser, Dominik; Toma, Simona; Hofmeister, Jeremy; Sinanaj, Indrit; Lovblad, Karl-Olof; Giannakopoulos, Panteleimon

2014-01-01

Previous studies showed that acute caffeine administration enhances task-related brain activation in elderly individuals with preserved cognition. To explore the effects of this widely used agent on cognition and brain activation in early phases of cognitive decline, we performed a double-blinded, placebo-controlled functional magnetic resonance imaging (fMRI) study during an n-back working memory task in 17 individuals with mild cognitive impairment (MCI) compared to 17 age-matched healthy controls (HC). All individuals were regular caffeine consumers with an overnight abstinence and given 200 mg caffeine versus placebo tablets 30 minutes before testing. Analyses included assessment of task-related activation (general linear model), functional connectivity (tensorial-independent component analysis, TICA), baseline perfusion (arterial spin labeling, ASL), grey matter density (voxel-based morphometry, VBM), and white matter microstructure (tract-based spatial statistics, TBSS). Acute caffeine administration induced a focal activation of the prefrontal areas in HC with a more diffuse and posteromedial activation pattern in MCI individuals. In MCI, TICA documented a significant caffeine-related enhancement in the prefrontal cortex, supplementary motor area, ventral premotor and parietal cortex as well as the basal ganglia and cerebellum. The absence of significant group differences in baseline ASL perfusion patterns supports a neuronal rather than a purely vascular origin of these differences. The VBM and TBSS analyses excluded potentially confounding differences in grey matter density and white matter microstructure between MCI and HC. The present findings suggest a posterior displacement of working memory-related brain activation patterns after caffeine administration in MCI that may represent a compensatory mechanism to counterbalance a frontal lobe dysfunction.

Development of brain tumor at six years after the onset of acute lymphoblastic leukemia

International Nuclear Information System (INIS)

Kumazaki, Hisami; Hanada, Ryoji; Kikuti, Akira; Ichikawa, Masataka; Yamamoto, Keiko; Aihara, Toshinori; Ogawa, Yoshihiro

1996-01-01

In October 1994, a 16-year-old boy was diagnosed as having a brain tumor in the left fronto-temporal region 5 years after completing treatment for acute lymphoblastic leukemia (ALL). The patient had been treated for ALL starting in 1988 when he was 10-year-old. He had received systemic chemotherapy and central nervous system prophylaxis, consisting of cranial irradiation (24 Gy) and intrathecal methotrexate. When the brain tumor was detected he was still in complete remission. The patient received only supportive therapy mainly for relief of increased intracranial pressure because the tumor was too large to resect in addition to being inappropriate for surgical treatment. He died in December 1994. On autopsy, pathological diagnosis of the brain tumor was anaplastic astrocytoma, which is a rare secondary malignancy though glioma is common. (author)

Prevention of pressure ulcers in patients undergoing sub-acute rehabilitation after severe brain injury

DEFF Research Database (Denmark)

Sachs, Marianne Brostrup; Wolffbrandt, Mia Moth; Poulsen, Ingrid

2018-01-01

OBJECTIVE: The aim of this study was to uncover efforts made by healthcare professionals to prevent pressure ulcers (PUs) in patients with severe brain injury undergoing treatment at a sub-acute rehabilitation department. BACKGROUND: PUs is a major burden for patients and also generate considerable...... healthcare costs. PUs are, nevertheless, prevalent in both secondary and primary care. DESIGN: In this qualitative study, we performed 24-hour observation on four patients undergoing rehabilitation for severe brain injury. An observation guide was developed inspired by the Braden Scale and Spradley's theory...... that patients' rehabilitation days be planned in such a manner that activities, mobilisation and training are conducted throughout the day and evening. We also recommend that professional staff are encouraged to seek information about the former life of patients with severe brain injury. This article...

Increased susceptibility of dystrophin-deficient brain to mild hypoxia

International Nuclear Information System (INIS)

Wallis, T.; Rae, C.; Bubb, W.A.; Head, S.I.

2002-01-01

Full text: Duchenne muscular dystrophy is an X-linked disorder resulting from total absence of the 427 kDa protein dystrophin. Dystrophin is normally expressed in the brain mainly in a neuronal subpopulation: cortical pyramidal cells, hippocampal CA1 neurons and cerebellar Purkinje cells. One suggested role for dystrophin is in colocalising mitochondrial creatine kinase with ADP translocase and ATP synthase in mitochondria. Brain tissue slices in the murine model of Duchenne dystrophy, the mdx mouse, have been shown to be more sensitive to hypoxia than control. In this work, we used 13 C NMR to monitor the metabolic response of mdx cortical brain tissue slices to normoxia (95%O 2 /5% CO 2 ) and mild hypoxia (95%air/5% CO 2 ). Under normoxic conditions, mdx cortical slices displayed increased net flux through the Krebs cycle and glutamate/glutamine cycle, consistent with the proposed GABA A lesion which results in decreased inhibitory input. By contrast, mild hypoxia resulted in a significant increase in the total pool size of lactate and decreased net flux of 13 C from [3- 13 C]pyruvate into glutamate C4, GABA C2 and Ala C2, as well as decreased anaplerotic activity as measured by the ratio of Asp C2: Asp C3 label. Mild hypoxia has a significantly greater effect on brain oxidative metabolism in mdx mice, than in control

Brain stem slice conditioned medium contains endogenous BDNF and GDNF that affect neural crest boundary cap cells in co-culture.

Science.gov (United States)

Kaiser, Andreas; Kale, Ajay; Novozhilova, Ekaterina; Siratirakun, Piyaporn; Aquino, Jorge B; Thonabulsombat, Charoensri; Ernfors, Patrik; Olivius, Petri

2014-05-30

Conditioned medium (CM), made by collecting medium after a few days in cell culture and then re-using it to further stimulate other cells, is a known experimental concept since the 1950s. Our group has explored this technique to stimulate the performance of cells in culture in general, and to evaluate stem- and progenitor cell aptitude for auditory nerve repair enhancement in particular. As compared to other mediums, all primary endpoints in our published experimental settings have weighed in favor of conditioned culture medium, where we have shown that conditioned culture medium has a stimulatory effect on cell survival. In order to explore the reasons for this improved survival we set out to analyze the conditioned culture medium. We utilized ELISA kits to investigate whether brain stem (BS) slice CM contains any significant amounts of brain-derived neurotrophic factor (BDNF) and glial cell derived neurotrophic factor (GDNF). We further looked for a donor cell with progenitor characteristics that would be receptive to BDNF and GDNF. We chose the well-documented boundary cap (BC) progenitor cells to be tested in our in vitro co-culture setting together with cochlear nucleus (CN) of the BS. The results show that BS CM contains BDNF and GDNF and that survival of BC cells, as well as BC cell differentiation into neurons, were enhanced when BS CM were used. Altogether, we conclude that BC cells transplanted into a BDNF and GDNF rich environment could be suitable for treatment of a traumatized or degenerated auditory nerve. Copyright © 2014 Elsevier B.V. All rights reserved.

Integrating interface slicing into software engineering processes

Science.gov (United States)

Beck, Jon

1993-01-01

Interface slicing is a tool which was developed to facilitate software engineering. As previously presented, it was described in terms of its techniques and mechanisms. The integration of interface slicing into specific software engineering activities is considered by discussing a number of potential applications of interface slicing. The applications discussed specifically address the problems, issues, or concerns raised in a previous project. Because a complete interface slicer is still under development, these applications must be phrased in future tenses. Nonetheless, the interface slicing techniques which were presented can be implemented using current compiler and static analysis technology. Whether implemented as a standalone tool or as a module in an integrated development or reverse engineering environment, they require analysis no more complex than that required for current system development environments. By contrast, conventional slicing is a methodology which, while showing much promise and intuitive appeal, has yet to be fully implemented in a production language environment despite 12 years of development.

ELECTROENCEPHALOGRAPHY SHOWING DYING BRAIN IN A PATIENT WITH ACUTE BACLOFEN POISONING

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A. Y. Mikhaylov

2017-01-01

Full Text Available We report a case of acute baclofen poisoning in a 23-year-old female patient, who committed suicide, which led to the development of a deep coma. The electroencephalogram on the first day recorded the phenomenon of “burst suppression”, which was seen as a sign of a dying brain. Subsequent studies have shown positive changes of the electroencephalogram and regression of neurological symptoms. Thus, the phenomenon of “burst suppression” in the depression of consciousness to deep coma and given adequate treatment, can be reversible.

Executive function disorder in acute traumatic brain injury in Manado, Indonesia

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Sekplin A.S. Sekeon

2015-01-01

Full Text Available Traumatic brain injury (TBI is known as a major cause of death and chronic disability worldwide. It is one of the leading causes of economic and social problems for patient, family and community. Patients will have serious complication on physics, mental and personality aspect. Executive function disorder is one of the cognitive functions that could be affected by TBI. There is scarcity of data about executive function in acute TBI, especially from developing countries. Our study aimed to investigate the association between acute TBI and executive function disorder. This study was a hospital-based cross-sectional study. Samples consisted of 20 patients and 40 demographically matched controls that meet the inclusion criteria. For executive function measurement we applied TMT-A, TMT-B and Stroop Test. The result showed that mean score of TMT-A for case group was 1.06 minute (95% CI 0.70-1.06 which was longer than control group (0.32 minute. For TMT- B test, the mean score was 2.68 minute (95% CI 2.05-2.8 for case group and 0.77 minute for control group. On Stroop Test 3 we found that the mean score was 17 correct items (95% CI 13.52-20.48 which was lower than control group (52.5. For all of the tests, we detected that acute TBI significantly associate with executive function disorder (p > 0.05. Conclusion: There was a significant association between acute TBI and executive function disorder.

Brain Activity Associated With Attention Deficits Following Chemotherapy for Childhood Acute Lymphoblastic Leukemia.

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Fellah, Slim; Cheung, Yin T; Scoggins, Matthew A; Zou, Ping; Sabin, Noah D; Pui, Ching-Hon; Robison, Leslie L; Hudson, Melissa M; Ogg, Robert J; Krull, Kevin R

2018-05-21

The impact of contemporary chemotherapy treatment for childhood acute lymphoblastic leukemia on central nervous system activity is not fully appreciated. Neurocognitive testing and functional magnetic resonance imaging (fMRI) were obtained in 165 survivors five or more years postdiagnosis (average age = 14.4 years, 7.7 years from diagnosis, 51.5% males). Chemotherapy exposure was measured as serum concentration of methotrexate following high-dose intravenous injection. Neurocognitive testing included measures of attention and executive function. fMRI was obtained during completion of two tasks, the continuous performance task (CPT) and the attention network task (ANT). Image analysis was performed using Statistical Parametric Mapping software, with contrasts targeting sustained attention, alerting, orienting, and conflict. All statistical tests were two-sided. Compared with population norms, survivors demonstrated impairment on number-letter switching (P < .001, a measure of cognitive flexibility), which was associated with treatment intensity (P = .048). Task performance during fMRI was associated with neurocognitive dysfunction across multiple tasks. Regional brain activation was lower in survivors diagnosed at younger ages for the CPT (bilateral parietal and temporal lobes) and the ANT (left parietal and right hippocampus). With higher serum methotrexate exposure, CPT activation decreased in the right temporal and bilateral frontal and parietal lobes, but ANT alerting activation increased in the ventral frontal, insula, caudate, and anterior cingulate. Brain activation during attention and executive function tasks was associated with serum methotrexate exposure and age at diagnosis. These findings provide evidence for compromised and compensatory changes in regional brain function that may help clarify the neural substrates of cognitive deficits in acute lymphoblastic leukemia survivors.

A survey of program slicing for software engineering

Science.gov (United States)

Beck, Jon

1993-01-01

This research concerns program slicing which is used as a tool for program maintainence of software systems. Program slicing decreases the level of effort required to understand and maintain complex software systems. It was first designed as a debugging aid, but it has since been generalized into various tools and extended to include program comprehension, module cohesion estimation, requirements verification, dead code elimination, and maintainence of several software systems, including reverse engineering, parallelization, portability, and reuse component generation. This paper seeks to address and define terminology, theoretical concepts, program representation, different program graphs, developments in static slicing, dynamic slicing, and semantics and mathematical models. Applications for conventional slicing are presented, along with a prognosis of future work in this field.

Comparing culprit lesions in ST-segment elevation and non-ST-segment elevation acute coronary syndrome with 64-slice multidetector computed tomography

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Huang, W.-C. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: w.c.huang@yahoo.com.tw; Liu, C.-P. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: cpliu@isca.vghks.gov.tw; Wu, M.-T. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Department of Radiology, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: wu.mingting@gmail.com; Mar, G.-Y. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: gymar@isca.vghks.gov.tw; Lin, S.-K. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: skyii89@yahoo.com.tw; Hsiao, S.-H. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: a841120@ms3.hinet.net; Lin, S.-L. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: sllin@isca.vghks.gov.tw; Chiou, K.-R. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: krchiou@isca.vghks.gov.tw

2010-01-15

Background: Classifying acute coronary syndrome (ACS) as ST elevation ACS (STE-ACS) or non-ST elevation ACS (NSTE-ACS) is critical for clinical prognosis and therapeutic decision-making. Assessing the differences in composition and configuration of culprit lesions between STE-ACS and NSTE-ACS can clarify their pathophysiologic differences. Objective: This study focused on evaluating the ability of 64-slice multidetector computed tomography (MDCT) to investigate these differences in culprit lesions in patients with STE-ACS and NSTE-ACS. Methods: Of 161 ACS cases admitted, 120 who fit study criteria underwent MDCT and conventional coronary angiography. The following MDCT data were analyzed: calcium volume, Agatston calcium scores, plaque area, plaque burden, remodeling index, and plaque density. Results: The MDCT angiography had a good correlation with conventional coronary angiography regarding the stenotic severity of culprit lesions (r = 0.86, p < 0.001). The STE-ACS culprit lesions (n = 54) had significantly higher luminal area stenosis (78.6 {+-} 21.2% vs. 66.7 {+-} 23.9%, p = 0.006), larger plaque burden (0.91 {+-} 0.10 vs. 0.84 {+-} 0.12, p = 0.007) and remodeling index (1.28 {+-} 0.34 vs. 1.16 {+-} 0.22, p = 0.021) than those with NSTE-ACS (n = 66). The percentage of expanding remodeling index (remodeling index >1.05) was significantly higher in the STE-ACS group (81.5% vs. 63.6%, p = 0.031). The patients with STE-ACS had significantly lower MDCT density of culprit lesions than patients with NSTE-ACS (25.8 {+-} 13.9 HU vs. 43.5 {+-} 19.1 HU, p < 0.001). Conclusions: Sixty-four-slice MDCT can accurately evaluate the stenotic severity and composition of culprit lesions in selected patients with either STE-ACS or NSTE-ACS. Culprit lesions in NSTE-ACS patients had significantly lower luminal area stenosis, plaque burden, remodeling index and higher MDCT density, which possibly reflect differences in the composition of vulnerable culprit plaques and thrombi.

POLYMORPHISM OF THE SYNDROME OF HYPERACTIVE URINARY BLADDER IN PATIENTS WITH ACUTE AND CHRONIC VASCULAR DISEASES OF THE BRAIN

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P. G. Shvarts

2016-01-01

Full Text Available Abstract. The paper discusses the main etiological, phenomenological and pathogenetic mechanisms of forming the syndrome of overactive bladder (OAB in patients with acute and chronic cerebrovascular diseases. Describes the role of melatonin, arginine vasopressin (AVP and corticotropin-releasing factor hormone (CRFH in maintaining the rhythms of urination, urine formation and retention of urine in norm and abnormalities in these systems in acute and chronic vascular pathology of the brain. Described phenomenology OAB syndrome in vascular diseases of the brain. Shows a differentiated approach to pharmacological correction in patients with different clinical variants of urinary disorders and urine formation in the framework of the OAB syndrome with the use of neurotransmitter therapy and hormonesensitive.

Tc99m-HMPAO Neuro--SPECT Assessment of Ischemic Penumbra in Acute Brain Infarct: Control of Intra-arterial Thrombolysis Treatment

International Nuclear Information System (INIS)

Mena, Francisco; Mena, Ismael; Ducci, Hector; Soto, Francisco; Pedraza, Luis; Contreras, Andrea; Miranda, Marcelo; Basaez, Esteban; Fruns, Manuel

2004-01-01

Acute brain infarct is a medical emergency potentially reversible if treated with thrombolysis, an approved therapy, if performed in the first 3 to 6 hours of evolution. Thrombolysis has many benefits, but it also has associated risks, mainly development of intracranial hemorrhage. The selection of which patient should receive this type of treatment had been an important research topic over the last decade. As a consequence neuroimaging of brain infarct has significantly improved during the last few years. A variety of diagnostic studies are now available in the evaluation of brain infarct and in particular of potentially reversible brain ischemia, including magnetic resonance imaging (MRI) diffusion-perfusion, perfusion computed tomography (CT) and functional neuroimaging techniques includes positron emission tomography (PET) and single-photon emission tomography (SPECT). The aim of this study is to present our experience with a group of patients that presented with acute brain ischemia and had a NeuroSPECT evaluation before and after intra-arterial thrombolysis and/or possible stent placement, in the treatment of acute brain infarct. Methods: 16 patients were treated acutely for a significant ischemic stroke with the following protocol. 1) Admission, and complete neurological evaluation. 2) Brain CT scan performed to rule out hemorrhage or established infarct. 3) IV injection of 1100MBq Tc 99m HMPAO (Ceretec tm ) 4) Conventional cerebral angiography and intra-arterial thrombolysis with tPA and /or angioplasty/stent if necessary. 5) NeuroSPECT assessment of ischemic penumbra (Pre-therapy results). 6) 14 of 16 patients received a NeuroSPECT (Post-therapy results) control at 24 hours. NeuroSPECT image acquisition was performed immediately following arterial thrombolysis with a dual Head Camera, Siemens ECAM, SHR collimators and conventional protocol. Image processing was performed using the Neurogam, Segami Corp. Software as previously reported in Alasbimn Journal 2

Clinical significance of determination of serum NSE and plasma ET, IGF-II, CNP levels in patients with acute brain injury

International Nuclear Information System (INIS)

Chen Bo

2010-01-01

Objective: To investigate the clinical significance of changes of plasma ET, IGF-II, CNP and serum NSE contents in patients with acute brain injury. Methods: Serum contents of neuron specific enolase (NSE) were measured with chemiluminescence immunoassay and plasma endothelin (ET), insulin-like growth factor-II (IGF-II) and C-type natriuretic peptide (CNP) were measured with radioimmunoassay in 30 patients with acute brain injury and 35 controls. Results: Serum contents of NSE and plasma IGF-II, CNP were not much different in patients with mild brain injury from those in controls (P >0.05), but plasma contents of ET were already significantly higher in patients with mild brain injury than those in controls(P < 0.01). The serum NSE and plasma ET levels in patients with moderate and severe brain injury were significantly higher than those in patients with mild brain injury and controls (P < 0.01). Decrease of plasma levels of IGF-II and CNP was not significant in patients with mild brain injury (vs controls). However, the plasma levels of IGF-II and CNP were significantly lower in patients with moderate and severe brain injury than those in patients with mild brain injury and controls (P <0.01). As a whole, the magnitude of changes of these parameters was proportional to the severity of the injury. Conclusion: Changes of serum NSE and plasma IGF-II, ET and CNP levels were closely related to the pathological process of brain injury. Determination of these parameters was of clinical importance for evaluation of the severity of injury and outcome prediction. (authors)

Progesterone for Acute Traumatic Brain Injury: A Systematic Review of Randomized Controlled Trials.

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Yunhui Zeng

Full Text Available To evaluate the efficacy and safety of progesterone administrated in patients with acute traumatic brain injury (TBI.PubMed/MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL, Clinicaltrials.gov, ISRCTN registry and WHO International Clinical Trials Registry Platform (ICTRP were searched for randomized controlled trials (RCTs comparing progesterone and placebo administrated in acute TBI patients. The primary outcome was mortality and the secondary outcomes were unfavorable outcomes and adverse events. A meta-analysis was conducted to evaluate the efficacy and safety of progesterone administrated in patients with acute TBI.A total of 6 studies met inclusion criteria, involving 2,476 patients. The risk of bias was considered to be low in 4 studies but high in the other 2 studies. The results of meta-analysis indicated progesterone did not reduce the mortality (RR = 0.83, 95% CI = 0.57-1.20 or unfavorable outcomes (RR = 0.89, 95% CI = 0.78-1.02 of acute TBI patients in comparison with placebo. Sensitivity analysis yielded consistent results. Progesterone was basically safe and well tolerated in TBI patients with the exception of increased risk of phlebitis or thrombophlebitis (RR = 3.03, 95% CI = 1.96-4.66.Despite some modest bias, present evidence demonstrated that progesterone was well tolerated but did not reduce the mortality or unfavorable outcomes of adult patients with acute TBI.

Distribution of melatonin receptor in human fetal brain

Institute of Scientific and Technical Information of China (English)

WANG Guo-quan; SHAO Fu-yuan; ZHAO Ying; LIU Zhi-min

2001-01-01

Objective: To study the distribution of 2 kinds of melatonin receptor subtypes (mtl and MT2) in human fetal brain. Methods: The fetal brain tissues were sliced and the distribution ofmelatonin receptors in human fetal brain were detected using immunohistochemistry and in situ hybridization. Results: Melatonin receptor mtl existed in the cerebellun and hypothalamus, melatonin receptor MT2 exists in hypothalamus, occipital and medulla. Conclusion: Two kinds of melatonin receptors, mtl and MT2 exist in the membrane and cytosol of brain cells, indicating that human fetal brain is a target organ of melatonin.

RF slice profile effects in magnetic resonance fingerprinting.

Science.gov (United States)

Hong, Taehwa; Han, Dongyeob; Kim, Min-Oh; Kim, Dong-Hyun

2017-09-01

The radio frequency (RF) slice profile effects on T1 and T2 estimation in magnetic resonance fingerprinting (MRF) are investigated with respect to time-bandwidth product (TBW), flip angle (FA) level and field inhomogeneities. Signal evolutions are generated incorporating the non-ideal slice selective excitation process using Bloch simulation and matched to the original dictionary with and without the non-ideal slice profile taken into account. For validation, phantom and in vivo experiments are performed at 3T. Both simulations and experiments results show that T1 and T2 error from non-ideal slice profile increases with increasing FA level, off-resonance, and low TBW values. Therefore, RF slice profile effects should be compensated for accurate determination of the MR parameters. Copyright © 2017 Elsevier Inc. All rights reserved.

Autoradiographic imaging of phosphoinositide turnover in the brain

International Nuclear Information System (INIS)

Hwang, P.M.; Bredt, D.S.; Snyder, S.H.

1990-01-01

With [ 3 H]cytidine as a precursor, phosphoinositide turnover can be localized in brain slices by selective autoradiography of the product [ 3 H]cytidine diphosphate diacylglycerol, which is membrane-bound. In the cerebellum, glutamatergic stimulation elicits an increase of phosphoinositide turnover only in Purkinje cells and the molecular layer. In the hippocampus, both glutamatergic and muscarinic cholinergic stimulation increase phosphoinositide turnover, but with distinct localizations. Cholinergic stimulation affects CA1, CA3, CA4, and subiculum, whereas glutamatergic effects are restricted to the subiculum and CA3. Imaging phosphoinositide turnover in brain slices, which are amenable to electrophysiologic studies, will permit a dynamic localized analysis of regulation of this second messenger in response to synaptic stimulation of specific neuronal pathways

NMR surprizes with thin slices and strong gradients

Energy Technology Data Exchange (ETDEWEB)

Gaedke, Achim; Kresse, Benjamin [Institute of Condensed Matter Physics, Technische Universitaet Darmstadt (Germany); Nestle, Nikolaus

2008-07-01

In the context of our work on diffusion-relaxation-coupling in thin excited slices, we perform NMR experiments in static magnetic field gradients up to 200 T/m. For slice thicknesses in the range of 10{mu}m, the frequency bandwidth of the excited slices becomes sufficiently narrow that free induction decays (FIDs) become observable despite the presence of the strong static gradient. The observed FIDs were also simulated using standard methods from MRI physics. Possible effects of diffusion during the FID duration are still minor at this slice thickness in water but might become dominant for smaller slices or more diffusive media. Furthermore, the detailed excitation structure of the RF pulses was studied in profiling experiments over the edge of a plane liquid cell. Side lobe effects to the slices will be discussed along with approaches to control them. The spatial resolution achieved in the profiling experiments furthermore allows the identification of thermal expansion phenomena in the NMR magnet. Measures to reduce the temperature drift problems are presented.

Physiological complexity of acute traumatic brain injury in patients treated with a brain oxygen protocol: utility of symbolic regression in predictive modeling of a dynamical system.

Science.gov (United States)

Narotam, Pradeep K; Morrison, John F; Schmidt, Michael D; Nathoo, Narendra

2014-04-01

Predictive modeling of emergent behavior, inherent to complex physiological systems, requires the analysis of large complex clinical data streams currently being generated in the intensive care unit. Brain tissue oxygen protocols have yielded outcome benefits in traumatic brain injury (TBI), but the critical physiological thresholds for low brain oxygen have not been established for a dynamical patho-physiological system. High frequency, multi-modal clinical data sets from 29 patients with severe TBI who underwent multi-modality neuro-clinical care monitoring and treatment with a brain oxygen protocol were analyzed. The inter-relationship between acute physiological parameters was determined using symbolic regression (SR) as the computational framework. The mean patient age was 44.4±15 with a mean admission GCS of 6.6±3.9. Sixty-three percent sustained motor vehicle accidents and the most common pathology was intra-cerebral hemorrhage (50%). Hospital discharge mortality was 21%, poor outcome occurred in 24% of patients, and good outcome occurred in 56% of patients. Criticality for low brain oxygen was intracranial pressure (ICP) ≥22.8 mm Hg, for mortality at ICP≥37.1 mm Hg. The upper therapeutic threshold for cerebral perfusion pressure (CPP) was 75 mm Hg. Eubaric hyperoxia significantly impacted partial pressure of oxygen in brain tissue (PbtO2) at all ICP levels. Optimal brain temperature (Tbr) was 34-35°C, with an adverse effect when Tbr≥38°C. Survivors clustered at [Formula: see text] Hg vs. non-survivors [Formula: see text] 18 mm Hg. There were two mortality clusters for ICP: High ICP/low PbtO2 and low ICP/low PbtO2. Survivors maintained PbtO2 at all ranges of mean arterial pressure in contrast to non-survivors. The final SR equation for cerebral oxygenation is: [Formula: see text]. The SR-model of acute TBI advances new physiological thresholds or boundary conditions for acute TBI management: PbtO2≥25 mmHg; ICP≤22 mmHg; CPP≈60-75�

Brain injury impairs working memory and prefrontal circuit function

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Colin James Smith

2015-11-01

Full Text Available More than 2.5 million Americans suffer a traumatic brain injury (TBI each year. Even mild to moderate traumatic brain injury causes long-lasting neurological effects. Despite its prevalence, no therapy currently exists to treat the underlying cause of cognitive impairment suffered by TBI patients. Following lateral fluid percussion injury (LFPI, the most widely used experimental model of TBI, we investigated alterations in working memory and excitatory/inhibitory synaptic balance in the prefrontal cortex. LFPI impaired working memory as assessed with a T-maze behavioral task. Field excitatory postsynaptic potentials recorded in the prefrontal cortex were reduced in slices derived from brain-injured mice. Spontaneous and miniature excitatory postsynaptic currents onto layer 2/3 neurons were more frequent in slices derived from LFPI mice while inhibitory currents onto layer 2/3 neurons were smaller after LFPI. Additionally, an increase in action potential threshold and concomitant decrease in firing rate was observed in layer 2/3 neurons in slices from injured animals. Conversely, no differences in excitatory or inhibitory synaptic transmission onto layer 5 neurons were observed; however, layer 5 neurons demonstrated a decrease in input resistance and action potential duration after LFPI. These results demonstrate synaptic and intrinsic alterations in prefrontal circuitry that may underlie working memory impairment caused by TBI.

Electrical coupling between hippocampal astrocytes in rat brain slices.

Science.gov (United States)

Meme, William; Vandecasteele, Marie; Giaume, Christian; Venance, Laurent

2009-04-01

Gap junctions in astrocytes play a crucial role in intercellular communication by supporting both biochemical and electrical coupling between adjacent cells. Despite the critical role of electrical coupling in the network organization of these glial cells, the electrophysiological properties of gap junctions have been characterized in cultures while no direct evidence has been sought in situ. In the present study, gap-junctional currents were investigated using simultaneous dual whole-cell patch-clamp recordings between astrocytes from rat hippocampal slices. Bidirectional electrotonic coupling was observed in 82% of the cell pairs with an average coupling coefficient of 5.1%. Double patch-clamp analysis indicated that junctional currents were independent of the transjunctional voltage over a range from -100 to +110 mV. Interestingly, astrocytic electrical coupling displayed weak low-pass filtering properties compared to neuronal electrical synapses. Finally, during uncoupling processes triggered by either the gap-junction inhibitor carbenoxolone or endothelin-1, an increase in the input resistance in the injected cell paralleled the decrease in the coupling coefficient. Altogether, these results demonstrate that hippocampal astrocytes are electrically coupled through gap-junction channels characterized by properties that are distinct from those of electrical synapses between neurons. In addition, gap-junctional communication is efficiently regulated by endogenous compounds. This is taken to represent a mode of communication that may have important implications for the functional role of astrocyte networks in situ.

Imaging human brain cyto- and myelo-architecture with quantitative OCT (Conference Presentation)

Science.gov (United States)

Boas, David A.; Wang, Hui; Konukoglu, Ender; Fischl, Bruce; Sakadzic, Sava; Magnain, Caroline V.

2017-02-01

No current imaging technology allows us to directly and without significant distortion visualize the microscopic and defining anatomical features of the human brain. Ex vivo histological techniques can yield exquisite planar images, but the cutting, mounting and staining that are required components of this type of imaging induce distortions that are different for each slice, introducing cross-slice differences that prohibit true 3D analysis. We are overcoming this issue by utilizing Optical Coherence Tomography (OCT) with the goal to image whole human brain cytoarchitectural and laminar properties with potentially 3.5 µm resolution in block-face without the need for exogenous staining. From the intrinsic scattering contrast of the brain tissue, OCT gives us images that are comparable to Nissl stains, but without the distortions introduced in standard histology as the OCT images are acquired from the block face prior to slicing and thus without the need for subsequent staining and mounting. We have shown that laminar and cytoarchitectural properties of the brain can be characterized with OCT just as well as with Nissl staining. We will present our recent advances to improve the axial resolution while maintaining contrast; improvements afforded by speckle reduction procedures; and efforts to obtain quantitative maps of the optical scattering coefficient, an intrinsic property of the tissue.

Intersection based motion correction of multislice MRI for 3-D in utero fetal brain image formation.

Science.gov (United States)

Kim, Kio; Habas, Piotr A; Rousseau, Francois; Glenn, Orit A; Barkovich, Anthony J; Studholme, Colin

2010-01-01

In recent years, postprocessing of fast multislice magnetic resonance imaging (MRI) to correct fetal motion has provided the first true 3-D MR images of the developing human brain in utero. Early approaches have used reconstruction based algorithms, employing a two-step iterative process, where slices from the acquired data are realigned to an approximate 3-D reconstruction of the fetal brain, which is then refined further using the improved slice alignment. This two step slice-to-volume process, although powerful, is computationally expensive in needing a 3-D reconstruction, and is limited in its ability to recover subvoxel alignment. Here, we describe an alternative approach which we term slice intersection motion correction (SIMC), that seeks to directly co-align multiple slice stacks by considering the matching structure along all intersecting slice pairs in all orthogonally planned slices that are acquired in clinical imaging studies. A collective update scheme for all slices is then derived, to simultaneously drive slices into a consistent match along their lines of intersection. We then describe a 3-D reconstruction algorithm that, using the final motion corrected slice locations, suppresses through-plane partial volume effects to provide a single high isotropic resolution 3-D image. The method is tested on simulated data with known motions and is applied to retrospectively reconstruct 3-D images from a range of clinically acquired imaging studies. The quantitative evaluation of the registration accuracy for the simulated data sets demonstrated a significant improvement over previous approaches. An initial application of the technique to studying clinical pathology is included, where the proposed method recovered up to 15 mm of translation and 30 degrees of rotation for individual slices, and produced full 3-D reconstructions containing clinically useful additional information not visible in the original 2-D slices.

Deficiency of vasodilator-stimulated phosphoprotein (VASP increases blood-brain-barrier damage and edema formation after ischemic stroke in mice.

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Peter Kraft

2010-12-01

Full Text Available Stroke-induced brain edema formation is a frequent cause of secondary infarct growth and deterioration of neurological function. The molecular mechanisms underlying edema formation after stroke are largely unknown. Vasodilator-stimulated phosphoprotein (VASP is an important regulator of actin dynamics and stabilizes endothelial barriers through interaction with cell-cell contacts and focal adhesion sites. Hypoxia has been shown to foster vascular leakage by downregulation of VASP in vitro but the significance of VASP for regulating vascular permeability in the hypoxic brain in vivo awaits clarification.Focal cerebral ischemia was induced in Vasp(-/- mice and wild-type (WT littermates by transient middle cerebral artery occlusion (tMCAO. Evan's Blue tracer was applied to visualize the extent of blood-brain-barrier (BBB damage. Brain edema formation and infarct volumes were calculated from 2,3,5-triphenyltetrazolium chloride (TTC-stained brain slices. Both mouse groups were carefully controlled for anatomical and physiological parameters relevant for edema formation and stroke outcome. BBB damage (p0.05 towards worse neurological outcomes.Our study identifies VASP as critical regulator of BBB maintenance during acute ischemic stroke. Therapeutic modulation of VASP or VASP-dependent signalling pathways could become a novel strategy to combat excessive edema formation in ischemic brain damage.

Thin slices of child personality: Perceptual, situational, and behavioral contributions.

Science.gov (United States)

Tackett, Jennifer L; Herzhoff, Kathrin; Kushner, Shauna C; Rule, Nicholas

2016-01-01

The present study examined whether thin-slice ratings of child personality serve as a resource-efficient and theoretically valid measurement of child personality traits. We extended theoretical work on the observability, perceptual accuracy, and situational consistency of childhood personality traits by examining intersource and interjudge agreement, cross-situational consistency, and convergent, divergent, and predictive validity of thin-slice ratings. Forty-five unacquainted independent coders rated 326 children's (ages 8-12) personality in 1 of 15 thin-slice behavioral scenarios (i.e., 3 raters per slice, for over 14,000 independent thin-slice ratings). Mothers, fathers, and children rated children's personality, psychopathology, and competence. We found robust evidence for correlations between thin-slice and mother/father ratings of child personality, within- and across-task consistency of thin-slice ratings, and convergent and divergent validity with psychopathology and competence. Surprisingly, thin-slice ratings were more consistent across situations in this child sample than previously found for adults. Taken together, these results suggest that thin slices are a valid and reliable measure to assess child personality, offering a useful method of measurement beyond questionnaires, helping to address novel questions of personality perception and consistency in childhood. (c) 2016 APA, all rights reserved).

Slices

KAUST Repository

McCrae, James

2011-01-01

Minimalist object representations or shape-proxies that spark and inspire human perception of shape remain an incompletely understood, yet powerful aspect of visual communication. We explore the use of planar sections, i.e., the contours of intersection of planes with a 3D object, for creating shape abstractions, motivated by their popularity in art and engineering. We first perform a user study to show that humans do define consistent and similar planar section proxies for common objects. Interestingly, we observe a strong correlation between user-defined planes and geometric features of objects. Further we show that the problem of finding the minimum set of planes that capture a set of 3D geometric shape features is both NP-hard and not always the proxy a user would pick. Guided by the principles inferred from our user study, we present an algorithm that progressively selects planes to maximize feature coverage, which in turn influence the selection of subsequent planes. The algorithmic framework easily incorporates various shape features, while their relative importance values are computed and validated from the user study data. We use our algorithm to compute planar slices for various objects, validate their utility towards object abstraction using a second user study, and conclude showing the potential applications of the extracted planar slice shape proxies. © 2011 ACM.

Regulation of Brain-Derived Neurotrophic Factor Exocytosis and Gamma-Aminobutyric Acidergic Interneuron Synapse by the Schizophrenia Susceptibility Gene Dysbindin-1.

Science.gov (United States)

Yuan, Qiang; Yang, Feng; Xiao, Yixin; Tan, Shawn; Husain, Nilofer; Ren, Ming; Hu, Zhonghua; Martinowich, Keri; Ng, Julia S; Kim, Paul J; Han, Weiping; Nagata, Koh-Ichi; Weinberger, Daniel R; Je, H Shawn

2016-08-15

Genetic variations in dystrobrevin binding protein 1 (DTNBP1 or dysbindin-1) have been implicated as risk factors in the pathogenesis of schizophrenia. The encoded protein dysbindin-1 functions in the regulation of synaptic activity and synapse development. Intriguingly, a loss of function mutation in Dtnbp1 in mice disrupted both glutamatergic and gamma-aminobutyric acidergic transmission in the cerebral cortex; pyramidal neurons displayed enhanced excitability due to reductions in inhibitory synaptic inputs. However, the mechanism by which reduced dysbindin-1 activity causes inhibitory synaptic deficits remains unknown. We investigated the role of dysbindin-1 in the exocytosis of brain-derived neurotrophic factor (BDNF) from cortical excitatory neurons, organotypic brain slices, and acute slices from dysbindin-1 mutant mice and determined how this change in BDNF exocytosis transsynaptically affected the number of inhibitory synapses formed on excitatory neurons via whole-cell recordings, immunohistochemistry, and live-cell imaging using total internal reflection fluorescence microscopy. A decrease in dysbindin-1 reduces the exocytosis of BDNF from cortical excitatory neurons, and this reduction in BDNF exocytosis transsynaptically resulted in reduced inhibitory synapse numbers formed on excitatory neurons. Furthermore, application of exogenous BDNF rescued the inhibitory synaptic deficits caused by the reduced dysbindin-1 level in both cultured cortical neurons and slice cultures. Taken together, our results demonstrate that these two genes linked to risk for schizophrenia (BDNF and dysbindin-1) function together to regulate interneuron development and cortical network activity. This evidence supports the investigation of the association between dysbindin-1 and BDNF in humans with schizophrenia. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Imaging skeletal anatomy of injured cervical spine specimens: comparison of single-slice vs multi-slice helical CT

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Obenauer, S.; Alamo, L.; Herold, T.; Funke, M.; Kopka, L.; Grabbe, E. [Department of Radiology, Georg August-University Goettingen, Robert-Koch-Strasse 40, 37075 Goettingen (Germany)

2002-08-01

Our objective was to compare a single-slice CT (SS-CT) scanner with a multi-slice CT (MS-CT) scanner in the depiction of osseous anatomic structures and fractures of the upper cervical spine. Two cervical spine specimens with artificial trauma were scanned with a SS-CT scanner (HighSpeed, CT/i, GE, Milwaukee, Wis.) by using various collimations (1, 3, 5 mm) and pitch factors (1, 1.5, 2, 3) and a four-slice helical CT scanner (LightSpeed, QX/i, GE, Milwaukee, Wis.) by using various table speeds ranging from 3.75 to 15 mm/rotation for a pitch of 0.75 and from 7.5 to 30 mm/rotation for a pitch of 1.5. Images were reconstructed with an interval of 1 mm. Sagittal and coronal multiplanar reconstructions of the primary and reconstructed data set were performed. For MS-CT a tube current resulting in equivalent image noise as with SS-CT was used. All images were judged by two observers using a 4-point scale. The best image quality for SS-CT was achieved with the smallest slice thickness (1 mm) and a pitch smaller than 2 resulting in a table speed of up to 2 mm per gantry rotation (4 points). A reduction of the slice thickness rather than of the table speed proved to be beneficial at MS-CT. Therefore, the optimal scan protocol in MS-CT included a slice thickness of 1.25 mm with a table speed of 7.5 mm/360 using a pitch of 1.5 (4 points), resulting in a faster scan time than when a pitch of 0.75 (4 points) was used. This study indicates that MS-CT could provide equivalent image quality at approximately four times the volume coverage speed of SS-CT. (orig.)

Early detection of consciousness in patients with acute severe traumatic brain injury.

Science.gov (United States)

Edlow, Brian L; Chatelle, Camille; Spencer, Camille A; Chu, Catherine J; Bodien, Yelena G; O'Connor, Kathryn L; Hirschberg, Ronald E; Hochberg, Leigh R; Giacino, Joseph T; Rosenthal, Eric S; Wu, Ona

2017-09-01

See Schiff (doi:10.1093/awx209) for a scientific commentary on this article. Patients with acute severe traumatic brain injury may recover consciousness before self-expression. Without behavioural evidence of consciousness at the bedside, clinicians may render an inaccurate prognosis, increasing the likelihood of withholding life-sustaining therapies or denying rehabilitative services. Task-based functional magnetic resonance imaging and electroencephalography techniques have revealed covert consciousness in the chronic setting, but these techniques have not been tested in the intensive care unit. We prospectively enrolled 16 patients admitted to the intensive care unit for acute severe traumatic brain injury to test two hypotheses: (i) in patients who lack behavioural evidence of language expression and comprehension, functional magnetic resonance imaging and electroencephalography detect command-following during a motor imagery task (i.e. cognitive motor dissociation) and association cortex responses during language and music stimuli (i.e. higher-order cortex motor dissociation); and (ii) early responses to these paradigms are associated with better 6-month outcomes on the Glasgow Outcome Scale-Extended. Patients underwent functional magnetic resonance imaging on post-injury Day 9.2 ± 5.0 and electroencephalography on Day 9.8 ± 4.6. At the time of imaging, behavioural evaluation with the Coma Recovery Scale-Revised indicated coma (n = 2), vegetative state (n = 3), minimally conscious state without language (n = 3), minimally conscious state with language (n = 4) or post-traumatic confusional state (n = 4). Cognitive motor dissociation was identified in four patients, including three whose behavioural diagnosis suggested a vegetative state. Higher-order cortex motor dissociation was identified in two additional patients. Complete absence of responses to language, music and motor imagery was only observed in coma patients. In patients with behavioural evidence

Modulation of methylmercury uptake by methionine: Prevention of mitochondrial dysfunction in rat liver slices by a mimicry mechanism

International Nuclear Information System (INIS)

Roos, Daniel Henrique; Puntel, Robson Luiz; Farina, Marcelo; Aschner, Michael; Bohrer, Denise; Rocha, Joao Batista T.; Vargas Barbosa, Nilda B. de

2011-01-01

Methylmercury (MeHg) is an ubiquitous environmental pollutant which is transported into the mammalian cells when present as the methylmercury-cysteine conjugate (MeHg-Cys). With special emphasis on hepatic cells, due to their particular propensity to accumulate an appreciable amount of Hg after exposure to MeHg, this study was performed to evaluate the effects of methionine (Met) on Hg uptake, reactive species (RS) formation, oxygen consumption and mitochondrial function/cellular viability in both liver slices and mitochondria isolated from these slices, after exposure to MeHg or the MeHg-Cys complex. The liver slices were pre-treated with Met (250 μM) 15 min before being exposed to MeHg (25 μM) or MeHg-Cys (25 μM each) for 30 min at 37 o C. The treatment with MeHg caused a significant increase in the Hg concentration in both liver slices and mitochondria isolated from liver slices. Moreover, the Hg uptake was higher in the group exposed to the MeHg-Cys complex. In the DCF (dichlorofluorescein) assay, the exposure to MeHg and MeHg-Cys produced a significant increase in DFC reactive species (DFC-RS) formation only in the mitochondria isolated from liver slices. As observed with Hg uptake, DFC-RS levels were significantly higher in the mitochondria treated with the MeHg-Cys complex compared to MeHg alone. MeHg exposure also caused a marked decrease in the oxygen consumption of liver slices when compared to the control group, and this effect was more pronounced in the liver slices treated with the MeHg-Cys complex. Similarly, the loss of mitochondrial activity/cell viability was greater in liver slices exposed to the MeHg-Cys complex when compared to slices treated only with MeHg. In all studied parameters, Met pre-treatment was effective in preventing the MeHg- and/or MeHg-Cys-induced toxicity in both liver slices and mitochondria. Part of the protection afforded by Met against MeHg may be related to a direct interaction with MeHg or to the competition of Met with

Correlation of NTD-silicon rod and slice resistivity

International Nuclear Information System (INIS)

Wolverton, W.M.

1984-01-01

Neutron transmutation doped silicon is an electronic material which presents an opportunity to explore a high level of resistivity characterization. This is due to its excellent uniformity of dopant concentration. Appropriate resistivity measurements on the ingot raw material can be used as a predictor of slice resistivity. Correlation of finished NTD rod (i.e. ingot) resistivity to as-cut slice resistivity (after the sawing process) is addressed in the scope of this paper. Empirical data show that the shift of slice-center resistivity compared to rod-end center resistivity is a function of a new kind of rod radial-resistivity gradient. This function has two domains, and most rods are in domain ''A''. Correlating equations show how to significantly improve the prediction of slice resistivity of rods in domain ''A''. The new rod resistivity specifications have resulted in manufacturing economies in the production of NTD silicon slices

Acute supramaximal exercise increases the brain oxygenation in relation to cognitive workload

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Cem Seref Bediz

2016-04-01

Full Text Available Single bout of exercise can improve the performance on cognitive tasks. However, cognitive responses may be controversial due to different type, intensity, and duration of exercise. In addition, the mechanism of the effect of acute exercise on brain is still unclear. This study was aimed to investigate the effects of supramaximal exercise on cognitive tasks by means of brain oxygenation monitoring. The brain oxygenation of Prefrontal cortex (PFC was measured on 35 healthy male volunteers via functional Near Infrared Spectroscopy (fNIRS system. Subjects performed 2-Back test before and after the supramaximal exercise (Wingate Anaerobic Test lasting 30-s on cycle ergometer. The PFC oxygenation change evaluation revealed that PFC oxygenation rise during post-exercise 2-Back task was considerably higher than those in pre-exercise 2-Back task. In order to describe the relationship between oxygenation change and exercise performance, subjects were divided into two groups as high performers (HP and low performers (LP according to their peak power values (PP obtained from the supramaximal test. The oxy-hemoglobin (oxy-Hb values were compared between pre- and post-exercise conditions within subjects and also between subjects according to peak power. When performers were compared, in the HP group, the oxy-Hb values in post-exercise 2-Back test were significantly higher than those in pre-exercise 2-Back test. HP had significantly higher post-exercise oxy-Hb change (Δ than those of LP. In addition, peak power values of the total group were significantly correlated with Δoxy-Hb. The key findings of the present study revealed that acute supramaximal exercise has an impact on the brain oxygenation during a cognitive task. Also, the higher the anaerobic PP describes the larger the oxy-Hb response in post-exercise cognitive task. The current study also demonstrated a significant correlation between peak power (exercise load and post-exercise hemodynamic

Three-dimensional assessment of brain tissue morphology

Science.gov (United States)

Müller, Bert; Germann, Marco; Jeanmonod, Daniel; Morel, Anne

2006-08-01

The microstructure of brain tissues becomes visible using different types of optical microscopy after the tissue sectioning. This preparation procedure introduces stress and strain in the anisotropic and inhomogeneous soft tissue slices, which are several 10 μm thick. Consequently, the three-dimensional dataset, generated out of the two-dimensional images with lateral submicrometer resolution, needs algorithms to correct the deformations, which can be significant for mellow tissue such as brain segments. The spatial resolution perpendicular to the slices is much worse with respect to the lateral sub-micrometer resolution. Therefore, we propose as complementary method the synchrotron-radiation-based micro computed tomography (SRμCT), which avoids any kind of preparation artifacts due to sectioning and histological processing and yields true micrometer resolution in the three orthogonal directions. The visualization of soft matter by the use of SRμCT, however, is often based on elaborate staining protocols, since the tissue exhibits (almost) the same x-ray absorption as the surrounding medium. Therefore, it is unexpected that human tissue from the pons and the medulla oblongata in phosphate buffer show several features such as the blood vessels and the inferior olivary nucleus without staining. The value of these tomograms lies especially in the precise non-rigid registration of the different sets of histological slices. Applications of this method to larger pieces of brain tissue, such as the human thalamus are planned in the context of stereotactic functional neurosurgery.

Acutely increasing δGABAA receptor activity impairs memory and inhibits synaptic plasticity in the hippocampus

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Paul David Whissell

2013-09-01

Full Text Available Extrasynaptic γ-aminobutyric acid type A (GABAA receptors that contain the δ subunit (δGABAA receptors are expressed in several brain regions including the dentate gyrus (DG and CA1 subfields of the hippocampus. Drugs that increase δGABAA receptor activity have been proposed as treatments for a variety of disorders including insomnia, epilepsy and chronic pain. Also, long-term pretreatment with the δGABAA receptor–preferring agonist 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP enhances discrimination memory and increases neurogenesis in the DG. Despite the potential therapeutic benefits of such treatments, the effects of acutely increasing δGABAA receptor activity on memory behaviors remain unknown. Here, we studied the effects of THIP (4 mg/kg, i.p. on memory performance in wild-type (WT and δGABAA receptor null mutant (Gabrd–/– mice. Additionally, the effects of THIP on long-term potentiation (LTP, a molecular correlate of memory, were studied within the DG and CA1 subfields of the hippocampus using electrophysiological recordings of field potentials in hippocampal slices. The results showed that THIP impaired performance in the Morris water maze, contextual fear conditioning and object recognition tasks in WT mice but not Gabrd–/– mice. Furthermore, THIP inhibited LTP in hippocampal slices from WT but not Gabrd–/– mice, an effect that was blocked by GABAA receptor antagonist bicuculline. Thus, acutely increasing δGABAA receptor activity impairs memory behaviors and inhibits synaptic plasticity. These results have important implications for the development of therapies aimed at increasing δGABAA receptor activity.

Acutely increasing δGABAA receptor activity impairs memory and inhibits synaptic plasticity in the hippocampus

Science.gov (United States)

Whissell, Paul D.; Eng, Dave; Lecker, Irene; Martin, Loren J.; Wang, Dian-Shi; Orser, Beverley A.

2013-01-01

Extrasynaptic γ-aminobutyric acid type A (GABAA) receptors that contain the δ subunit (δGABAA receptors) are expressed in several brain regions including the dentate gyrus (DG) and CA1 subfields of the hippocampus. Drugs that increase δGABAA receptor activity have been proposed as treatments for a variety of disorders including insomnia, epilepsy and chronic pain. Also, long-term pretreatment with the δGABAA receptor–preferring agonist 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP) enhances discrimination memory and increases neurogenesis in the DG. Despite the potential therapeutic benefits of such treatments, the effects of acutely increasing δGABAA receptor activity on memory behaviors remain unknown. Here, we studied the effects of THIP (4 mg/kg, i.p.) on memory performance in wild-type (WT) and δGABAA receptor null mutant (Gabrd−/−) mice. Additionally, the effects of THIP on long-term potentiation (LTP), a molecular correlate of memory, were studied within the DG and CA1 subfields of the hippocampus using electrophysiological recordings of field potentials in hippocampal slices. The results showed that THIP impaired performance in the Morris water maze, contextual fear conditioning and object recognition tasks in WT mice but not Gabrd−/− mice. Furthermore, THIP inhibited LTP in hippocampal slices from WT but not Gabrd−/− mice, an effect that was blocked by GABAA receptor antagonist bicuculline. Thus, acutely increasing δGABAA receptor activity impairs memory behaviors and inhibits synaptic plasticity. These results have important implications for the development of therapies aimed at increasing δGABAA receptor activity. PMID:24062648

Investigation of the slice sensitivity profile for step-and-shoot mode multi-slice computed tomography

International Nuclear Information System (INIS)

Hsieh Jiang

2001-01-01

Multislice computed tomography (MCT) is one of the recent technology advancements in CT. Compared to single slice CT, MCT significantly improves examination time, x-ray tube efficiency, and contrast material utilization. Although the scan mode of MCT is predominately helical, step-and-shoot (axial) scans continue to be an important part of routine clinical protocols. In this paper, we present a detailed investigation on the slice sensitivity profile (SSP) of MCT in the step-and-shoot mode. Our investigation shows that, unlike single slice CT, the SSP for MCT exhibits multiple peaks and valleys resulting from intercell gaps between detector rows. To fully understand the characteristics of the SSP, we developed an analytical model to predict the behavior of MCT. We propose a simple experimental technique that can quickly and accurately measure SSP. The impact of the SSP on image artifacts and low contrast detectability is also investigated

A three-dimensional MRI atlas of the zebra finch brain in stereotaxic coordinates

DEFF Research Database (Denmark)

Poirier, Colline; Vellema, Michiel; Verhoye, Marleen

2008-01-01

of different brain areas (nuclei) involved in the sensory and motor control of song. Until now, the only published atlases of songbird brains consisted in drawings based on histological slices of the canary and of the zebra finch brain. Taking advantage of high-magnetic field (7 Tesla) MRI technique, we...

Computer simulations suggest that acute correction of hyperglycaemia with an insulin bolus protocol might be useful in brain FDG PET

Energy Technology Data Exchange (ETDEWEB)

Buchert, R.; Brenner, W.; Apostolova, I.; Mester, J.; Clausen, M. [University Medical Center Hamburg-Eppendorf (Germany). Dept. of Nuclear Medicine; Santer, R. [University Medical Center Hamburg-Eppendorf (Germany). Center for Gynaecology, Obstetrics and Paediatrics; Silverman, D.H.S. [David Geffen School of Medicine at UCLA, Los Angeles, CA (United States). Dept. of Molecular and Medical Pharmacology

2009-07-01

FDG PET in hyperglycaemic subjects often suffers from limited statistical image quality, which may hamper visual and quantitative evaluation. In our study the following insulin bolus protocol is proposed for acute correction of hyperglycaemia (> 7.0 mmol/l) in brain FDG PET. (i) Intravenous bolus injection of short-acting insulin, one I.E. for each 0.6 mmol/l blood glucose above 7.0. (ii) If 20 min after insulin administration plasma glucose is {<=} 7.0 mmol/l, proceed to (iii). If insulin has not taken sufficient effect step back to (i). Compute insulin dose with the updated blood glucose level. (iii) Wait further 20 min before injection of FDG. (iv) Continuous supervision of the patient during the whole scanning procedure. The potential of this protocol for improvement of image quality in brain FDG PET in hyperglycaemic subjects was evaluated by computer simulations within the Sokoloff model. A plausibility check of the prediction of the computer simulations on the magnitude of the effect that might be achieved by correction of hyperglycaemia was performed by retrospective evaluation of the relation between blood glucose level and brain FDG uptake in 89 subjects in whom FDG PET had been performed for diagnosis of Alzheimer's disease. The computer simulations suggested that acute correction of hyperglycaemia according to the proposed bolus insulin protocol might increase the FDG uptake of the brain by up to 80%. The magnitude of this effect was confirmed by the patient data. The proposed management protocol for acute correction of hyperglycaemia with insulin has the potential to significantly improve the statistical quality of brain FDG PET images. This should be confirmed in a prospective study in patients. (orig.)

Computer simulations suggest that acute correction of hyperglycaemia with an insulin bolus protocol might be useful in brain FDG PET

International Nuclear Information System (INIS)

Buchert, R.; Brenner, W.; Apostolova, I.; Mester, J.; Clausen, M.; Santer, R.; Silverman, D.H.S.

2009-01-01

FDG PET in hyperglycaemic subjects often suffers from limited statistical image quality, which may hamper visual and quantitative evaluation. In our study the following insulin bolus protocol is proposed for acute correction of hyperglycaemia (> 7.0 mmol/l) in brain FDG PET. (i) Intravenous bolus injection of short-acting insulin, one I.E. for each 0.6 mmol/l blood glucose above 7.0. (ii) If 20 min after insulin administration plasma glucose is ≤ 7.0 mmol/l, proceed to (iii). If insulin has not taken sufficient effect step back to (i). Compute insulin dose with the updated blood glucose level. (iii) Wait further 20 min before injection of FDG. (iv) Continuous supervision of the patient during the whole scanning procedure. The potential of this protocol for improvement of image quality in brain FDG PET in hyperglycaemic subjects was evaluated by computer simulations within the Sokoloff model. A plausibility check of the prediction of the computer simulations on the magnitude of the effect that might be achieved by correction of hyperglycaemia was performed by retrospective evaluation of the relation between blood glucose level and brain FDG uptake in 89 subjects in whom FDG PET had been performed for diagnosis of Alzheimer's disease. The computer simulations suggested that acute correction of hyperglycaemia according to the proposed bolus insulin protocol might increase the FDG uptake of the brain by up to 80%. The magnitude of this effect was confirmed by the patient data. The proposed management protocol for acute correction of hyperglycaemia with insulin has the potential to significantly improve the statistical quality of brain FDG PET images. This should be confirmed in a prospective study in patients. (orig.)

Three-dimensional inversion recovery manganese-enhanced MRI of mouse brain using super-resolution reconstruction to visualize nuclei involved in higher brain function.

Science.gov (United States)

Poole, Dana S; Plenge, Esben; Poot, Dirk H J; Lakke, Egbert A J F; Niessen, Wiro J; Meijering, Erik; van der Weerd, Louise

2014-07-01

The visualization of activity in mouse brain using inversion recovery spin echo (IR-SE) manganese-enhanced MRI (MEMRI) provides unique contrast, but suffers from poor resolution in the slice-encoding direction. Super-resolution reconstruction (SRR) is a resolution-enhancing post-processing technique in which multiple low-resolution slice stacks are combined into a single volume of high isotropic resolution using computational methods. In this study, we investigated, first, whether SRR can improve the three-dimensional resolution of IR-SE MEMRI in the slice selection direction, whilst maintaining or improving the contrast-to-noise ratio of the two-dimensional slice stacks. Second, the contrast-to-noise ratio of SRR IR-SE MEMRI was compared with a conventional three-dimensional gradient echo (GE) acquisition. Quantitative experiments were performed on a phantom containing compartments of various manganese concentrations. The results showed that, with comparable scan times, the signal-to-noise ratio of three-dimensional GE acquisition is higher than that of SRR IR-SE MEMRI. However, the contrast-to-noise ratio between different compartments can be superior with SRR IR-SE MEMRI, depending on the chosen inversion time. In vivo experiments were performed in mice receiving manganese using an implanted osmotic pump. The results showed that SRR works well as a resolution-enhancing technique in IR-SE MEMRI experiments. In addition, the SRR image also shows a number of brain structures that are more clearly discernible from the surrounding tissues than in three-dimensional GE acquisition, including a number of nuclei with specific higher brain functions, such as memory, stress, anxiety and reward behavior. Copyright © 2014 John Wiley & Sons, Ltd.

Mathematical Modeling of Thin Layer Microwave Drying of Taro Slices

Science.gov (United States)

Kumar, Vivek; Sharma, H. K.; Singh, K.

2016-03-01

The present study investigated the drying kinetics of taro slices precooked in different medium viz water (WC), steam (SC) and Lemon Solution (LC) and dried at different microwave power 360, 540 and 720 W. Drying curves of all precooked slices at all microwave powers showed falling rate period along with a very short accelerating period at the beginning of the drying. At all microwave powers, higher drying rate was observed for LC slices as compared to WC and SC slices. To select a suitable drying curve, seven thin-layer drying models were fitted to the experimental data. The data revealed that the Page model was most adequate in describing the microwave drying behavior of taro slices precooked in different medium. The highest effective moisture diffusivity value of 2.11 × 10-8 m2/s was obtained for LC samples while the lowest 0.83 × 10-8 m2/s was obtained for WC taro slices. The activation energy (E a ) of LC taro slices was lower than the E a of WC and SC taro slices.

High-precision surface formation and the 3-D shaded display of the brain obtained from CT images

International Nuclear Information System (INIS)

Niki, Noboru; Higuti, Kiyofumi; Takahashi, Yoshizo

1986-01-01

High-precision reconstruction of surface and 3-D shaded display of the target organ and lesions, obtained from CT images, aid in medical recognition. Firstly, this paper points out some problems of using a conventional method, in which brain surface is reconstructed from the known contour of brain slices, in 3-D shaded display of the brain in a dog. Secondly, a new high-precision technique for reconstructing complex brain surface from brain contour is proposed. The principle of the technique consists of extracting data of outline surface and fissures, smoothing of brain contour, and recomposition of the data of outline surface and fissures into a composite surface image. Finally, the validity of the method was verified by successfully reconstructing complex brain surface from the contour of dog brain slices. In addition, it was possible to cut brain surface, obtained by the newly developed technique, in any voluntary plane and to display CT values on the sections. (Namekawa, K.)

A BDNF loop-domain mimetic acutely reverses spontaneous apneas and respiratory abnormalities during behavioral arousal in a mouse model of Rett syndrome

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Miriam Kron

2014-09-01

Full Text Available Reduced levels of brain-derived neurotrophic factor (BDNF are thought to contribute to the pathophysiology of Rett syndrome (RTT, a severe neurodevelopmental disorder caused by loss-of-function mutations in the gene encoding methyl-CpG-binding protein 2 (MeCP2. In Mecp2 mutant mice, BDNF deficits have been associated with breathing abnormalities, a core feature of RTT, as well as with synaptic hyperexcitability within the brainstem respiratory network. Application of BDNF can reverse hyperexcitability in acute brainstem slices from Mecp2-null mice, suggesting that therapies targeting BDNF or its receptor, TrkB, could be effective at acute reversal of respiratory abnormalities in RTT. Therefore, we examined the ability of LM22A-4, a small-molecule BDNF loop-domain mimetic and TrkB partial agonist, to modulate synaptic excitability within respiratory cell groups in the brainstem nucleus tractus solitarius (nTS and to acutely reverse abnormalities in breathing at rest and during behavioral arousal in Mecp2 mutants. Patch-clamp recordings in Mecp2-null brainstem slices demonstrated that LM22A-4 decreases excitability at primary afferent synapses in the nTS by reducing the amplitude of evoked excitatory postsynaptic currents and the frequency of spontaneous and miniature excitatory postsynaptic currents. In vivo, acute treatment of Mecp2-null and -heterozygous mutants with LM22A-4 completely eliminated spontaneous apneas in resting animals, without sedation. Moreover, we demonstrate that respiratory dysregulation during behavioral arousal, a feature of human RTT, is also reversed in Mecp2 mutants by acute treatment with LM22A-4. Together, these data support the hypothesis that reduced BDNF signaling and respiratory dysfunction in RTT are linked, and establish the proof-of-concept that treatment with a small-molecule structural mimetic of a BDNF loop domain and a TrkB partial agonist can acutely reverse abnormal breathing at rest and in response to

The in vitro isolated whole guinea pig brain as a model to study epileptiform activity patterns.

Science.gov (United States)

de Curtis, Marco; Librizzi, Laura; Uva, Laura

2016-02-15

Research on ictogenesis is based on the study of activity between seizures and during seizures in animal models of epilepsy (chronic condition) or in in vitro slices obtained from naïve non-epileptic brains after treatment with pro-convulsive drugs, manipulations of the extracellular medium and specific stimulation protocols. The in vitro isolated guinea pig brain retains the functional connectivity between brain structures and maintains interactions between neuronal, glial and vascular compartments. It is a close-to-in vivo preparation that offers experimental advantages not achieved with the use of other experimental models. Neurophysiological and imaging techniques can be utilized in this preparation to study brain activity during and between seizures induced by pharmacological or functional manipulations. Cellular and network determinants of interictal and ictal discharges that reproduce abnormal patterns observed in human focal epilepsies and the associated changes in extracellular ion and blood-brain permeability can be identified and analyzed in the isolated guinea pig brain. Ictal and interictal patterns recorded in in vitro slices may show substantial differences from seizure activity recorded in vivo due to slicing procedure itself. The isolated guinea pig brain maintained in vitro by arterial perfusion combines the typical facilitated access of in vitro preparations, that are difficult to approach during in vivo experiments, with the preservation of larger neuronal networks. The in vitro whole isolated guinea pig brain preparation offers an unique experimental model to study systemic and neurovascular changes during ictogenesis. Published by Elsevier B.V.

Multi-detector computed tomography of acute abdomen

International Nuclear Information System (INIS)

Leschka, Sebastian; Alkadhi, Hatem; Wildermuth, Simon; Marincek, Borut; University Hospital of Zurich

2005-01-01

Acute abdominal pain is one of the most common causes for referrals to the emergency department. The sudden onset of severe abdominal pain characterising the ''acute abdomen'' requires rapid and accurate identification of a potentially life-threatening abdominal pathology to provide a timely referral to the appropriate physician. While the physical examination and laboratory investigations are often non-specific, computed tomography (CT) has evolved as the first-line imaging modality in patients with an acute abdomen. Because the new multi-detector CT (MDCT) scanner generations provide increased speed, greater volume coverage and thinner slices, the acceptance of CT for abdominal imaging has increased rapidly. The goal of this article is to discuss the role of MDCT in the diagnostic work-up of acute abdominal pain. (orig.)

Biological Signatures of Brain Damage Associated with High Serum Ferritin Levels in Patients with Acute Ischemic Stroke and Thrombolytic Treatment

Directory of Open Access Journals (Sweden)

Mónica Millán

2008-01-01

Full Text Available Background and purpose: Increased body iron stores have been related to greater oxidative stress and brain injury in clinical and experimental cerebral ischemia and reperfusion. We aimed to investigate the biological signatures of excitotoxicity, inflammation and blood brain barrier disruption potentially associated with high serum ferritin levels-related damage in acute stroke patients treated with i.v. t-PA.

MR spectroscopy-based brain metabolite profiling in propionic acidaemia: metabolic changes in the basal ganglia during acute decompensation and effect of liver transplantation

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McKiernan Patrick J

2011-05-01

Full Text Available Abstract Background Propionic acidaemia (PA results from deficiency of Propionyl CoA carboxylase, the commonest form presenting in the neonatal period. Despite best current management, PA is associated with severe neurological sequelae, in particular movement disorders resulting from basal ganglia infarction, although the pathogenesis remains poorly understood. The role of liver transplantation remains controversial but may confer some neuro-protection. The present study utilises quantitative magnetic resonance spectroscopy (MRS to investigate brain metabolite alterations in propionic acidaemia during metabolic stability and acute encephalopathic episodes. Methods Quantitative MRS was used to evaluate brain metabolites in eight children with neonatal onset propionic acidaemia, with six elective studies acquired during metabolic stability and five studies during acute encephalopathic episodes. MRS studies were acquired concurrently with clinically indicated MR imaging studies at 1.5 Tesla. LCModel software was used to provide metabolite quantification. Comparison was made with a dataset of MRS metabolite concentrations from a cohort of children with normal appearing MR imaging. Results MRI findings confirm the vulnerability of basal ganglia to infarction during acute encephalopathy. We identified statistically significant decreases in basal ganglia glutamate+glutamine and N-Acetylaspartate, and increase in lactate, during encephalopathic episodes. In white matter lactate was significantly elevated but other metabolites not significantly altered. Metabolite data from two children who had received liver transplantation were not significantly different from the comparator group. Conclusions The metabolite alterations seen in propionic acidaemia in the basal ganglia during acute encephalopathy reflect loss of viable neurons, and a switch to anaerobic respiration. The decrease in glutamine + glutamate supports the hypothesis that they are consumed to

RETROSPECTIVE DETECTION OF INTERLEAVED SLICE ACQUISITION PARAMETERS FROM FMRI DATA

Science.gov (United States)

Parker, David; Rotival, Georges; Laine, Andrew; Razlighi, Qolamreza R.

2015-01-01

To minimize slice excitation leakage to adjacent slices, interleaved slice acquisition is nowadays performed regularly in fMRI scanners. In interleaved slice acquisition, the number of slices skipped between two consecutive slice acquisitions is often referred to as the ‘interleave parameter’; the loss of this parameter can be catastrophic for the analysis of fMRI data. In this article we present a method to retrospectively detect the interleave parameter and the axis in which it is applied. Our method relies on the smoothness of the temporal-distance correlation function, which becomes disrupted along the axis on which interleaved slice acquisition is applied. We examined this method on simulated and real data in the presence of fMRI artifacts such as physiological noise, motion, etc. We also examined the reliability of this method in detecting different types of interleave parameters and demonstrated an accuracy of about 94% in more than 1000 real fMRI scans. PMID:26161244

Inducing rat brain CYP2D with nicotine increases the rate of codeine tolerance; predicting the rate of tolerance from acute analgesic response.

Science.gov (United States)

McMillan, Douglas M; Tyndale, Rachel F

2017-12-01

Repeated opioid administration produces analgesic tolerance, which may lead to dose escalation. Brain CYP2D metabolizes codeine to morphine, a bioactivation step required for codeine analgesia. Higher brain, but not liver, CYP2D is found in smokers and nicotine induces rat brain, but not liver, CYP2D expression and activity. Nicotine induction of rat brain CYP2D increases acute codeine conversion to morphine, and analgesia, however the role of brain CYP2D on the effects of repeated codeine exposure and tolerance is unknown. Rats were pretreated with nicotine (brain CYP2D inducer; 1mg/kg subcutaneously) or vehicle (saline; 1ml/kg subcutaneously). Codeine (40-60mg/kg oral-gavage) or morphine (20-30mg/kg oral-gavage) was administered daily and analgesia was assessed daily using the tail-flick reflex assay. Nicotine (versus saline) pretreatment increased acute codeine analgesia (1.32-fold change in AUC 0-60 min ; pnicotine did not alter acute morphine analgesia (1.03-fold; p>0.8), or the rate of morphine tolerance (8.1%/day versus 7.6%; p>0.9). The rate of both codeine and morphine tolerance (loss in peak analgesia from day 1 to day 4) correlated with initial analgesic response on day 1 (R=0.97, p<001). Increasing brain CYP2D altered initial analgesia and subsequent rate of tolerance. Variation in an individual's initial response to analgesic (e.g. high initial dose, smoking) may affect the rate of tolerance, and thereby the risk for dose escalation and/or opioid dependence. Copyright © 2017 Elsevier Inc. All rights reserved.

Acutely increasing δGABA(A) receptor activity impairs memory and inhibits synaptic plasticity in the hippocampus.

Science.gov (United States)

Whissell, Paul D; Eng, Dave; Lecker, Irene; Martin, Loren J; Wang, Dian-Shi; Orser, Beverley A

2013-01-01

Extrasynaptic γ-aminobutyric acid type A (GABA(A)) receptors that contain the δ subunit (δGABA(A) receptors) are expressed in several brain regions including the dentate gyrus (DG) and CA1 subfields of the hippocampus. Drugs that increase δGABA(A) receptor activity have been proposed as treatments for a variety of disorders including insomnia, epilepsy and chronic pain. Also, long-term pretreatment with the δGABA(A) receptor-preferring agonist 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP) enhances discrimination memory and increases neurogenesis in the DG. Despite the potential therapeutic benefits of such treatments, the effects of acutely increasing δGABA(A) receptor activity on memory behaviors remain unknown. Here, we studied the effects of THIP (4 mg/kg, i.p.) on memory performance in wild-type (WT) and δGABA(A) receptor null mutant (Gabrd(-/-)) mice. Additionally, the effects of THIP on long-term potentiation (LTP), a molecular correlate of memory, were studied within the DG and CA1 subfields of the hippocampus using electrophysiological recordings of field potentials in hippocampal slices. The results showed that THIP impaired performance in the Morris water maze, contextual fear conditioning and object recognition tasks in WT mice but not Gabrd(-/-) mice. Furthermore, THIP inhibited LTP in hippocampal slices from WT but not Gabrd(-/-) mice, an effect that was blocked by GABA(A) receptor antagonist bicuculline. Thus, acutely increasing δGABA(A) receptor activity impairs memory behaviors and inhibits synaptic plasticity. These results have important implications for the development of therapies aimed at increasing δGABA(A) receptor activity.

Altered brain concentrations of citalopram and escitalopram in P-glycoprotein deficient mice after acute and chronic treatment.

Science.gov (United States)

Karlsson, Louise; Carlsson, Björn; Hiemke, Christoph; Ahlner, Johan; Bengtsson, Finn; Schmitt, Ulrich; Kugelberg, Fredrik C

2013-11-01

According to both in vitro and in vivo data P-glycoprotein (P-gp) may restrict the uptake of several antidepressants into the brain, thus contributing to the poor success rate of current antidepressant therapies. The therapeutic activity of citalopram resides in the S-enantiomer, whereas the R-enantiomer is practically devoid of serotonin reuptake potency. To date, no in vivo data are available that address whether the enantiomers of citalopram and its metabolites are substrates of P-gp. P-gp knockout (abcb1ab (-/-)) and wild-type (abcb1ab (+/+)) mice underwent acute (single-dose) and chronic (two daily doses for 10 days) treatment with citalopram (10mg/kg) or escitalopram (5mg/kg) Serum and brain samples were collected 1-6h after the first or last i.p. injection for subsequent drug analysis by an enantioselective HPLC method. In brain, 3-fold higher concentrations of S- and R-citalopram, and its metabolites, were found in abcb1ab (-/-) mice than in abcb1ab (+/+) mice after both acute and chronic citalopram treatments. After escitalopram treatment, the S-citalopram brain concentration was 3-5 times higher in the knockout mice than in controls. The results provide novel evidence that the enantiomers of citalopram are substrates of P-gp. Possible clinical and toxicological implications of this finding need to be further elucidated. Copyright © 2013 Elsevier B.V. and ECNP. All rights reserved.

The hypothalamic slice approach to neuroendocrinology.

Science.gov (United States)

Hatton, G I

1983-07-01

The magnocellular peptidergic cells of the supraoptic and paraventricular nuclei comprise much of what is known as the hypothalamo-neurohypophysial system and is involved in several functions, including body fluid balance, parturition and lactation. While we have learned much from experiments in vivo, they have not produced a clear understanding of some of the crucial features associated with the functioning of this system. In particular, questions relating to the osmosensitivity of magnocellular neurones and the mechanism(s) by which their characteristic firing patterns are generated have not been answered using the older approaches. Electrophysiological studies with brain slices present direct evidence for osmosensitivity, and perhaps even osmoreceptivity, of magnocellular neurones. Other evidence indicates that the phasic bursting patterns of activity associated with vasopressin-releasing neurones (a) occur in the absence of patterned chemical synaptic input, (b) may be modulated by electrotonic conduction across gap junctions connecting magnocellular neurones and (c) are likely to be generated by endogenous membrane currents. These results make untenable the formerly held idea that phasic bursting activity is dependent upon recurrent synaptic inhibition.

Water-activity of dehydrated guava slices sweeteners

International Nuclear Information System (INIS)

Ayub, M.; Zeb, A.; Ullah, J.

2005-01-01

A study was carried out to investigate the individual and combined effect of caloric sweeteners (sucrose, glucose and fructose) and non-caloric sweeteners (saccharine, cyclamate and aspartame) along with antioxidants (citric acid and ascorbic acid) and chemical preservatives (potassium metabisulphite and potassium sorbate) on the water-activity (a/sub w/) of dehydrated guava slices. Different dilutions of caloric sweeteners (20, 30, 40 and 50 degree brix (bx) and non-caloric sweeteners (equivalent to sucrose sweetness) were used. Guava slices were osmotically dehydrated in these solutions and then dehydrated initially at 0 and then at 60 degree C to final moisture-content of 20-25%. Guava slices prepared with sucrose: glucose 7:3 potassium metabisulphite, ascorbic acid and citric acid produced best quality products, which have minimum (a/sub w/) and best overall sensory characteristics. The analysis showed that treatments and their various concentrations had a significant effect (p=0.05) on (a/sub w/) of dehydrated guava slices. (author)

Interactive Slice of the CMS detector

CERN Multimedia

Davis, Siona Ruth

2016-01-01

This slice shows a colorful cross-section of the CMS detector with all parts of the detector labelled. Viewers are invited to click on buttons associated with five types of particles to see what happens when each type interacts with the sections of the detector. The five types of particles users can select to send through the slice are muons, electrons, neutral hadrons, charged hadrons and photons. Supplementary information on each type of particles is given. Useful for inclusion into general talks on CMS etc. *Animated CMS "slice" for Powerpoint (Mac & PC) Original version - 2004 Updated version - July 2010 *Six slides required - first is a set of buttons; others are for each particle type (muon, electron, charged/neutral hadron, photon) Recommend putting slide 1 anywhere in your presentation and the rest at the end

MRI of fetal acquired brain lesions

International Nuclear Information System (INIS)

Prayer, Daniela; Brugger, Peter C.; Kasprian, Gregor; Witzani, Linde; Helmer, Hanns; Dietrich, Wolfgang; Eppel, Wolfgang; Langer, Martin

2006-01-01

Acquired fetal brain damage is suspected in cases of destruction of previously normally formed tissue, the primary cause of which is hypoxia. Fetal brain damage may occur as a consequence of acute or chronic maternal diseases, with acute diseases causing impairment of oxygen delivery to the fetal brain, and chronic diseases interfering with normal, placental development. Infections, metabolic diseases, feto-fetal transfusion syndrome, toxic agents, mechanical traumatic events, iatrogenic accidents, and space-occupying lesions may also qualify as pathologic conditions that initiate intrauterine brain damage. MR manifestations of acute fetal brain injury (such as hemorrhage or acute ischemic lesions) can easily be recognized, as they are hardly different from postnatal lesions. The availability of diffusion-weighted sequences enhances the sensitivity in recognizing acute ischemic lesions. Recent hemorrhages are usually readily depicted on T2 (*) sequences, where they display hypointense signals. Chronic fetal brain injury may be characterized by nonspecific changes that must be attributable to the presence of an acquired cerebral pathology. The workup in suspected acquired fetal brain injury also includes the assessment of extra-CNS organs that may be affected by an underlying pathology. Finally, the placenta, as the organ that mediates oxygen delivery from the maternal circulation to the fetus, must be examined on MR images

MRI of fetal acquired brain lesions

Energy Technology Data Exchange (ETDEWEB)

Prayer, Daniela [Department of Radiodiagnostics, Medical University of Vienna (Austria)]. E-mail: daniela.prayer@meduniwien.ac.at; Brugger, Peter C. [Center of Anatomy and Cell Biology, Medical University of Vienna (Austria); Kasprian, Gregor [Department of Radiodiagnostics, Medical University of Vienna (Austria); Witzani, Linde [Department of Radiodiagnostics, Medical University of Vienna (Austria); Helmer, Hanns [Department of Obstetrics and Gynecology, Medical University of Vienna (Austria); Dietrich, Wolfgang [Department of Neurosurgery, Medical University of Vienna (Austria); Eppel, Wolfgang [Department of Obstetrics and Gynecology, Medical University of Vienna (Austria); Langer, Martin [Department of Obstetrics and Gynecology, Medical University of Vienna (Austria)

2006-02-15

Acquired fetal brain damage is suspected in cases of destruction of previously normally formed tissue, the primary cause of which is hypoxia. Fetal brain damage may occur as a consequence of acute or chronic maternal diseases, with acute diseases causing impairment of oxygen delivery to the fetal brain, and chronic diseases interfering with normal, placental development. Infections, metabolic diseases, feto-fetal transfusion syndrome, toxic agents, mechanical traumatic events, iatrogenic accidents, and space-occupying lesions may also qualify as pathologic conditions that initiate intrauterine brain damage. MR manifestations of acute fetal brain injury (such as hemorrhage or acute ischemic lesions) can easily be recognized, as they are hardly different from postnatal lesions. The availability of diffusion-weighted sequences enhances the sensitivity in recognizing acute ischemic lesions. Recent hemorrhages are usually readily depicted on T2 (*) sequences, where they display hypointense signals. Chronic fetal brain injury may be characterized by nonspecific changes that must be attributable to the presence of an acquired cerebral pathology. The workup in suspected acquired fetal brain injury also includes the assessment of extra-CNS organs that may be affected by an underlying pathology. Finally, the placenta, as the organ that mediates oxygen delivery from the maternal circulation to the fetus, must be examined on MR images.

Development of a bread slicing machine from locally sourced ...

African Journals Online (AJOL)

This paper presents the development of a bread slicing machine which is a mechanical device that is used for slicing bread instead of the crude cumbersome and unhygienic method of manual slicing of bread. In an attempt to facilitate the final processing of bread which is a common daily food requirement of most Nigerians ...

[Correlation between post-stroke pneumonia and outcome in patients with acute brain infarction].

Science.gov (United States)

Li, S J; Hu, H Q; Wang, X L; Cao, B Z

2016-09-20

Objective: To investigate the correlation between post-stroke pneumonia and outcome in patients with acute brain infarction. Methods: Consecutive acute cerebral infarction patients who were hospitalized in Department of Neurology, Jinan Military General Hospital were prospectively recruited from August 2010 to August 2014. The baseline data including age, sex, the National Institute of Health Stroke Scale (NIHSS) scores, type of Oxfordshire Community Stroke Project (OCSP: total anterior circulation infarct, partial anterior circulation infarct, posterior circulation infarct and lacunar infarct), fasting blood glucose etc. after admission were recorded. Post-stroke pneumonia was diagnosed by treating physician according to criteria for hospital-acquired pneumonia of the Centers for Disease Control and Prevention. Recovery was assessed by modified Rankin Scale (mRS) 180 days after stroke by telephone interview (mRS≤2 reflected good prognosis, and mRS>2 reflected unfavorable prognosis). Multinominal Logistic regression analysis, Kaplan-Meier curve and log rank test were used. Results: A total of 1 249 patients were enrolled, among them 173 patients were lost during follow-up. A total of 159 patients had post-stroke pneumonia, while 1 090 patients were without post-stroke. Compared with patients without post-stoke pneumonia, patients with post-stroke pneumonia were older (67±13 vs 63±12 years, P =0.000), more severe (NIHSS, 15(14) vs 4(4), P =0.000). Compared with patients without post-stoke pneumonia, more patients with post-stroke pneumonia suffered from heart failure (12.58% vs 3.40%, P =0.000), atrial fibrillation (26.42% vs 8.81%, P =0.000), myocardial infarction (10.06% vs 5.05%, P =0.016), recurrent brain infarction (30.19% vs 22.66%, P =0.045), total anterior circulation infarct type of OCSP (46.54% vs 19.63%, P =0.000), posterior circulation infarct of OCSP (39.62% vs 25.51%, P =0.001); more patients suffered from disorder of consciousness (60.38% vs 9

Mapping metals in Parkinson's and normal brain using rapid-scanning x-ray fluorescence

International Nuclear Information System (INIS)

Popescu, Bogdan F Gh; George, Martin J; McCrea, Richard P E; Devon, Richard M; George, Graham N; Hanson, Akela D; Chapman, L Dean; Nichol, Helen; Bergmann, Uwe; Garachtchenko, Alex V; Luening, Katharina; Kelly, Michael E; Harder, Sheri M; Pickering, Ingrid J

2009-01-01

Rapid-scanning x-ray fluorescence (RS-XRF) is a synchrotron technology that maps multiple metals in tissues by employing unique hardware and software to increase scanning speed. RS-XRF was validated by mapping and quantifying iron, zinc and copper in brain slices from Parkinson's disease (PD) and unaffected subjects. Regions and structures in the brain were readily identified by their metal complement and each metal had a unique distribution. Many zinc-rich brain regions were low in iron and vice versa. The location and amount of iron in brain regions known to be affected in PD agreed with analyses using other methods. Sample preparation is simple and standard formalin-fixed autopsy slices are suitable. RS-XRF can simultaneously and non-destructively map and quantify multiple metals and holds great promise to reveal metal pathologies associated with PD and other neurodegenerative diseases as well as diseases of metal metabolism.

Cardiac tissue slices: preparation, handling, and successful optical mapping.

Science.gov (United States)

Wang, Ken; Lee, Peter; Mirams, Gary R; Sarathchandra, Padmini; Borg, Thomas K; Gavaghan, David J; Kohl, Peter; Bollensdorff, Christian

2015-05-01

Cardiac tissue slices are becoming increasingly popular as a model system for cardiac electrophysiology and pharmacology research and development. Here, we describe in detail the preparation, handling, and optical mapping of transmembrane potential and intracellular free calcium concentration transients (CaT) in ventricular tissue slices from guinea pigs and rabbits. Slices cut in the epicardium-tangential plane contained well-aligned in-slice myocardial cell strands ("fibers") in subepicardial and midmyocardial sections. Cut with a high-precision slow-advancing microtome at a thickness of 350 to 400 μm, tissue slices preserved essential action potential (AP) properties of the precutting Langendorff-perfused heart. We identified the need for a postcutting recovery period of 36 min (guinea pig) and 63 min (rabbit) to reach 97.5% of final steady-state values for AP duration (APD) (identified by exponential fitting). There was no significant difference between the postcutting recovery dynamics in slices obtained using 2,3-butanedione 2-monoxime or blebistatin as electromechanical uncouplers during the cutting process. A rapid increase in APD, seen after cutting, was caused by exposure to ice-cold solution during the slicing procedure, not by tissue injury, differences in uncouplers, or pH-buffers (bicarbonate; HEPES). To characterize intrinsic patterns of CaT, AP, and conduction, a combination of multipoint and field stimulation should be used to avoid misinterpretation based on source-sink effects. In summary, we describe in detail the preparation, mapping, and data analysis approaches for reproducible cardiac tissue slice-based investigations into AP and CaT dynamics. Copyright © 2015 the American Physiological Society.

Specificity of exogenous acetate and glutamate as astrocyte substrates examined in acute brain slices from female mice using methionine sulfoximine (MSO) to inhibit glutamine synthesis

DEFF Research Database (Denmark)

Andersen, Jens Velde; McNair, Laura Frendrup; Schousboe, Arne

2017-01-01

Removal of endogenously released glutamate is mediated primarily by astrocytes and exogenous (13) C-labeled glutamate has been applied to study glutamate metabolism in astrocytes. Likewise, studies have clearly established the relevance of (13) C-labeled acetate as an astrocyte specific metabolic...... cortical slices from female NMRI mice were incubated in media containing [1,2-(13) C]acetate or [U-(13) C]glutamate, with or without methionine sulfoximine (MSO) to inhibit glutamine synthetase (GS). Tissue extracts were analyzed by gas chromatography-mass spectrometry. Blocking GS abolished the majority...... of glutamine (13) C-labeling from [1,2-(13) C]acetate as intended. However, (13) C-labeling of GABA was only 40-50% reduced by MSO, suggesting considerable neuronal uptake of acetate. Moreover, labeling of glutamate from [1,2-(13) C]acetate in the presence of MSO exceeded the level probable from exclusive...

Influence of γ-irradiation on drying of slice potato

International Nuclear Information System (INIS)

Wang Jun; Chao Yan; Fu Junjie; Wang Jianping

2001-01-01

A new technology is introduced to dry food products by hot-air after pretreated by irradiation. The influence of different dosage of irradiation, temperature of hot air, thickness of the slice potato on the rate of dehydration temperature of irradiated potato were studied. A conclusion is reached that the 3 factors, irradiation dosage, hot-air temperature and thickness of slice potato, affect the rate of dehydration and temperature of slice potato. The higher the dosage is, the greater the rate of dehydration of potato becomes, and the higher the temperature of the slice potato gets. (authors)

[3H] glycogen hydrolysis in brain slices: responses to meurotransmitters and modulation of noradrenaline receptors

International Nuclear Information System (INIS)

Quach, T.T.; Rose, C.; Schwartz, J.C.

1978-01-01

Different agents have been investigated for their effects on [ 3 H] glycogen synthesized in mouse cortical slices. Of these noradrenaline, serotonin and histamine induced clear concentration-dependent glycogenesis. [ 3 H] glycogen hydrolysis induced by noradrenaline appears to be mediated by beta-adrenergic receptors because it is completely prevented by timolol, while phentolamine is ineffective. It seems to involve cyclic AMP because it is potentiated in the presence of isobutylmethylxanthine; in addition dibutyryl cyclic AMP (but not dibutyryl cyclic GMP) promotes glycogenolysis. Lower concentrations of noradrenaline were necessary for [ 3 H] glycogen hydrolysis (ECsub(50) 0.5μM) than for stimulation of cyclic AMP accumulation (ECsub(50) = 8μM). After subchronic reserpine treatment the concentration-response curve to noradrenaline was significantly shifted to the left (ECsub(50) = 0.09 +- 0.02 μM as compared with 0.49 +- 0.08μM in saline-pretreated mice) without modifications of either the basal [ 3 H] glycogen level, maximal glycogenolytic effect, or the dibutyryl cAMP-induced glycogenolytic response. In addition to noradrenaline, clear concentration-dependent [ 3 H] glycogen hydrolysis was observed in the presence of histamine or serotonin. In contrast to the partial [ 3 H] glycogen hydrolysis elicited by these biogenic amines, depolarization of the slices by 50 mM K + provoked a nearly total [ 3 H] glycogen hydrolysis. (author)

Influence of the slice thickness in CT to clinical effect

International Nuclear Information System (INIS)

Kimura, Kazue; Katakura, Toshihiko; Ito, Masami; Okuaki, Okihisa; Suzuki, Kenji

1980-01-01

CT is a kind of tomography. Therefore, what thickness of tissue is being observed in the picture - this is important in the clinical application of CT. The influence of slice thickness on the pictures, especially its clinical effect, was examined. The apparatus used is EMI CT 5005. For varying the slice thickness, it cannot be any larger than the thickness essential to the apparatus. Therefore, to make it thinner than the essential 14 mm, collimators were specially prepared, which were used on the sides of an X-ray tube and a detector. As basic observation, the revelation ability of form owing to the difference of slice thickness using acryl pipes, and the revelation ability of slice face owing to the difference of slice thickness, were examined. About clinical observation, the results for certain cases of cancer were compared with the CT images for the slice thickness of 14 mm essential to EMI CT 5005 and the slice thickness of 7 mm achieved by means of the collimators. (J.P.N.)

Metabolic therapy for temporal lobe epilepsy in a dish: investigating mechanisms of ketogenic diet using electrophysiological recordings in hippocampal slices

Directory of Open Access Journals (Sweden)

Masahito Kawamura

2016-11-01

Full Text Available The hippocampus is prone to epileptic seizures and is a key brain region and experimental platform for investigating mechanisms associated with the abnormal neuronal excitability that characterizes a seizure. Accordingly, the hippocampal slice is a common in vitro model to study treatments that may prevent or reduce seizure activity. The ketogenic diet is a metabolic therapy used to treat epilepsy in adults and children for nearly 100 years; it can reduce or eliminate even severe or refractory seizures. New insights into its underlying mechanisms have been revealed by diverse types of electrophysiological recordings in hippocampal slices. Here we review these reports and their relevant mechanistic findings. We acknowledge that a major difficulty in using hippocampal slices is the inability to reproduce precisely the in vivo condition of ketogenic diet feeding in any in vitro preparation, and progress has been made in this in vivo/in vitro transition. Thus far at least three different approaches are reported to reproduce relevant diet effects in the hippocampal slices: (1 direct application of ketone bodies, (2 mimicking the ketogenic diet condition during a whole-cell patch-clamp technique, and (3 reduced glucose incubation of hippocampal slices from ketogenic diet–fed animals. Significant results have been found with each of these methods and provide options for further study into short- and long-term mechanisms including ATP-sensitive potassium channels, vesicular glutamate transporter, pannexin channels and adenosine receptors underlying ketogenic diet and other forms of metabolic therapy.

Metabolic Therapy for Temporal Lobe Epilepsy in a Dish: Investigating Mechanisms of Ketogenic Diet using Electrophysiological Recordings in Hippocampal Slices

Science.gov (United States)

Kawamura, Masahito Jr.; Ruskin, David N.; Masino, Susan A.

2016-01-01

The hippocampus is prone to epileptic seizures and is a key brain region and experimental platform for investigating mechanisms associated with the abnormal neuronal excitability that characterizes a seizure. Accordingly, the hippocampal slice is a common in vitro model to study treatments that may prevent or reduce seizure activity. The ketogenic diet is a metabolic therapy used to treat epilepsy in adults and children for nearly 100 years; it can reduce or eliminate even severe or refractory seizures. New insights into its underlying mechanisms have been revealed by diverse types of electrophysiological recordings in hippocampal slices. Here we review these reports and their relevant mechanistic findings. We acknowledge that a major difficulty in using hippocampal slices is the inability to reproduce precisely the in vivo condition of ketogenic diet feeding in any in vitro preparation, and progress has been made in this in vivo/in vitro transition. Thus far at least three different approaches are reported to reproduce relevant diet effects in the hippocampal slices: (1) direct application of ketone bodies; (2) mimicking the ketogenic diet condition during a whole-cell patch-clamp technique; and (3) reduced glucose incubation of hippocampal slices from ketogenic diet–fed animals. Significant results have been found with each of these methods and provide options for further study into short- and long-term mechanisms including Adenosine triphosphate (ATP)-sensitive potassium (KATP) channels, vesicular glutamate transporter (VGLUT), pannexin channels and adenosine receptors underlying ketogenic diet and other forms of metabolic therapy. PMID:27847463

Metabolomics of Therapy Response in Preclinical Glioblastoma: A Multi-Slice MRSI-Based Volumetric Analysis for Noninvasive Assessment of Temozolomide Treatment

Science.gov (United States)

Arias-Ramos, Nuria; Ferrer-Font, Laura; Lope-Piedrafita, Silvia; Mocioiu, Victor; Julià-Sapé, Margarida; Pumarola, Martí; Arús, Carles; Candiota, Ana Paula

2017-01-01

Glioblastoma (GBM) is the most common aggressive primary brain tumor in adults, with a short survival time even after aggressive therapy. Non-invasive surrogate biomarkers of therapy response may be relevant for improving patient survival. Previous work produced such biomarkers in preclinical GBM using semi-supervised source extraction and single-slice Magnetic Resonance Spectroscopic Imaging (MRSI). Nevertheless, GBMs are heterogeneous and single-slice studies could prevent obtaining relevant information. The purpose of this work was to evaluate whether a multi-slice MRSI approach, acquiring consecutive grids across the tumor, is feasible for preclinical models and may produce additional insight into therapy response. Nosological images were analyzed pixel-by-pixel and a relative responding volume, the Tumor Responding Index (TRI), was defined to quantify response. Heterogeneous response levels were observed and treated animals were ascribed to three arbitrary predefined groups: high response (HR, n = 2), TRI = 68.2 ± 2.8%, intermediate response (IR, n = 6), TRI = 41.1 ± 4.2% and low response (LR, n = 2), TRI = 13.4 ± 14.3%, producing therapy response categorization which had not been fully registered in single-slice studies. Results agreed with the multi-slice approach being feasible and producing an inverse correlation between TRI and Ki67 immunostaining. Additionally, ca. 7-day oscillations of TRI were observed, suggesting that host immune system activation in response to treatment could contribute to the responding patterns detected. PMID:28524099

Metabolomics of Therapy Response in Preclinical Glioblastoma: A Multi-Slice MRSI-Based Volumetric Analysis for Noninvasive Assessment of Temozolomide Treatment

Directory of Open Access Journals (Sweden)

Nuria Arias-Ramos

2017-05-01

Full Text Available Glioblastoma (GBM is the most common aggressive primary brain tumor in adults, with a short survival time even after aggressive therapy. Non-invasive surrogate biomarkers of therapy response may be relevant for improving patient survival. Previous work produced such biomarkers in preclinical GBM using semi-supervised source extraction and single-slice Magnetic Resonance Spectroscopic Imaging (MRSI. Nevertheless, GBMs are heterogeneous and single-slice studies could prevent obtaining relevant information. The purpose of this work was to evaluate whether a multi-slice MRSI approach, acquiring consecutive grids across the tumor, is feasible for preclinical models and may produce additional insight into therapy response. Nosological images were analyzed pixel-by-pixel and a relative responding volume, the Tumor Responding Index (TRI, was defined to quantify response. Heterogeneous response levels were observed and treated animals were ascribed to three arbitrary predefined groups: high response (HR, n = 2, TRI = 68.2 ± 2.8%, intermediate response (IR, n = 6, TRI = 41.1 ± 4.2% and low response (LR, n = 2, TRI = 13.4 ± 14.3%, producing therapy response categorization which had not been fully registered in single-slice studies. Results agreed with the multi-slice approach being feasible and producing an inverse correlation between TRI and Ki67 immunostaining. Additionally, ca. 7-day oscillations of TRI were observed, suggesting that host immune system activation in response to treatment could contribute to the responding patterns detected.

Measurement of elemental distributions in mouse brain by using submilli-PIXE camera

International Nuclear Information System (INIS)

Fujiki, K.; Matsuyama, S.; Ishii, K.

2010-01-01

In a biological body, trace elements including metallic elements play important roles. Knowing their spatial distribution and amounts, we can find out some relations among a physiological role of the trace element in vivo, the function, and the disease appearance. In this study, we investigated a method to obtain elemental distributions in whole brain slice taken from mental disease model mice and control mice using in-air submilli-PIXE camera at Tohoku University. We administered 5-BrdU that was the analogue of the thymidine as a marker to detect a new born cell in especially the dentate gyrus of the hippocampus. We obtained the elemental distributions of the whole brain of subject and control mice. From elemental distributions of the brain of a mental disease model mouse, a brain contained light elements, such as P, S, Cl and K, which were uniformly distributed over the brain. Fe was accumulated in the specific area of brain. Elemental concentration of Fe was more than 10 times higher than that in the other. However, the accumulation of iron in brain slices was not observed in those of control mice. Zn is accumulated in the vicinity in hippocampus. Br was uniformly distributed over the brain. The submilli-PIXE camera will provide a powerful tool for this research. (author)

Whole brain, high resolution spin-echo resting state fMRI using PINS multiplexing at 7 T

NARCIS (Netherlands)

Koopmans, P.J.; Boyacioglu, R.; Barth, M.; Norris, David Gordon

2012-01-01

This article demonstrates the application of spin-echo EPI for resting state fMRI at 7 T. A short repetition time of 1860 ms was made possible by the use of slice multiplexing which permitted whole brain coverage at high spatial resolution (84 slices of 1.6 mm thickness). Radiofrequency power

Usefulness of {sup 99m}Tc-ECD brain SPECT in acute onset pediatric CNS diseases. In comparison with CT and MRI

Energy Technology Data Exchange (ETDEWEB)

Hashimoto, Teisuke; Chikatsu, Hiroko; Nishiyama, Hiromune; Endo, Hiroko; Kono, Tatsuo; Iimura, Fumitoshi; Kuwashima, Shigeko; Saiki, Natoru; Fujioka, Mutsuhisa [Dokkyo Univ., Mibu, Tochigi (Japan). School of Medicine

2001-07-01

The purpose of this study was to assess the usefulness of regional cerebral blood flow (rCBF) measured by {sup 99m}Tc-L, L-ethyl cysteinate dimer (ECD) brain SPECT in the acute onset type of pediatric central nervous system (CNS) diseases. Thirteen children (7 girls, 6 boys, 4 month-12 years of age) who were diagnosed with 9 cases of viral encephalitis, two cases of febrile convulsion and one each of migraine and metabolic disorder underwent {sup 99m}Tc-ECD brain SPECT, CT and/or MRI within one week interval. The incidence of abnormal findings in the 13 patients was 96.4% (30/31) on {sup 99m}Tc-ECD brain SPECT, 17.6% (3/17) on CT and 63.6% (14/22) on MRI. The positive detection rate of {sup 99m}Tc-ECD brain SPECT was statistically (P<0.01 by a {chi}{sup 2} and/or Fisher's exact probability test) higher than those of CT and MRI. And the changes in rCBF were demonstrated. {sup 99m}Tc-ECD brain SPECT is a useful examination for the diagnosis and follow up management in patients with the acute onset type of pediatric CNS diseases. (author)

Quantitative analysis of brain metabolites concentrations using MR spectroscopy in acute hypoxia ischemic encephalopathy

International Nuclear Information System (INIS)

Xiao Yeyu; Wang HaiYu; Shen Zhiwei; Lin Yan; Chen Yaowen; Xiao Gang; Wu Renhua

2010-01-01

Objective: To evaluate the absolute quantification of brain metabolites concentrations using external standard MRS in acute hypoxia ischemia encephalopathy (HIE) piglet model. Method: Eight 7-day-old healthy piglets were subjected to insult of hypoxia ischemia (HI). The animals and an external standard phantom containing detectable metabolites of known concentrations were studied on a 1.5 T GE Signa scanner. The single-voxel proton magnetic resonance spectroscopy ( 1 H-MRS) data were processed using LCModel software, and the quantification of N-acetylaspartate (NAA), creatine (Cr) and lactate (Lac) were accomplished. Multivariate analysis of variance was performed to compare the NAA, Cr, Lac concentration differences in the brains of piglets pre- and post-HI (0h). In addition, the dynamic changes of brain metabolites concentrations of 2 HIE piglets were observed at the time points of 0 h and 2 h. Results: One piglet was excluded because it was over anesthetized to death. Seven piglets' data were analyzed. The concentrations of NAA pre- and post-HI were (6.86±0.49) mmol/kg and (5.73±0.88) mmol/kg respectively, they were (4.65±0.73) mmol/kg and (4.40±0.80) mmol/kg for Cr; and were 0.00 mmol/kg and (0.43±0.39) mmol/kg for Lac. After HI, decreased NAA concentration immediately was observed, and it was of statistical significance (F=8.608, P=0.013). The concentration of Cr was insignificantly decreased (F=0.379, P=0.550). The concentration of Lac was increased, and the difference was of statistical significance (F=8.600, P=0.013). Dynamic observation showed a Lac peak immediately after HI and it decreased after 2 h post-HI. Conclusions: External standard MRS using LCModel has great value in the quantitative analysis of brain metabolites. The changes of NAA and Lac concentrations are sensitive to reflect the early metabolic change of acute HIE. (authors)

The topology of large-scale structure. VI - Slices of the universe

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Park, Changbom; Gott, J. R., III; Melott, Adrian L.; Karachentsev, I. D.

1992-03-01

Results of an investigation of the topology of large-scale structure in two observed slices of the universe are presented. Both slices pass through the Coma cluster and their depths are 100 and 230/h Mpc. The present topology study shows that the largest void in the CfA slice is divided into two smaller voids by a statistically significant line of galaxies. The topology of toy models like the white noise and bubble models is shown to be inconsistent with that of the observed slices. A large N-body simulation was made of the biased cloud dark matter model and the slices are simulated by matching them in selection functions and boundary conditions. The genus curves for these simulated slices are spongelike and have a small shift in the direction of a meatball topology like those of observed slices.

The topology of large-scale structure. VI - Slices of the universe

Science.gov (United States)

Park, Changbom; Gott, J. R., III; Melott, Adrian L.; Karachentsev, I. D.

1992-01-01

Results of an investigation of the topology of large-scale structure in two observed slices of the universe are presented. Both slices pass through the Coma cluster and their depths are 100 and 230/h Mpc. The present topology study shows that the largest void in the CfA slice is divided into two smaller voids by a statistically significant line of galaxies. The topology of toy models like the white noise and bubble models is shown to be inconsistent with that of the observed slices. A large N-body simulation was made of the biased cloud dark matter model and the slices are simulated by matching them in selection functions and boundary conditions. The genus curves for these simulated slices are spongelike and have a small shift in the direction of a meatball topology like those of observed slices.

Insulin Stimulates S100B Secretion and These Proteins Antagonistically Modulate Brain Glucose Metabolism.

Science.gov (United States)

Wartchow, Krista Minéia; Tramontina, Ana Carolina; de Souza, Daniela F; Biasibetti, Regina; Bobermin, Larissa D; Gonçalves, Carlos-Alberto

2016-06-01

Brain metabolism is highly dependent on glucose, which is derived from the blood circulation and metabolized by the astrocytes and other neural cells via several pathways. Glucose uptake in the brain does not involve insulin-dependent glucose transporters; however, this hormone affects the glucose influx to the brain. Changes in cerebrospinal fluid levels of S100B (an astrocyte-derived protein) have been associated with alterations in glucose metabolism; however, there is no evidence whether insulin modulates glucose metabolism and S100B secretion. Herein, we investigated the effect of S100B on glucose metabolism, measuring D-(3)H-glucose incorporation in two preparations, C6 glioma cells and acute hippocampal slices, and we also investigated the effect of insulin on S100B secretion. Our results showed that: (a) S100B at physiological levels decreases glucose uptake, through the multiligand receptor RAGE and mitogen-activated protein kinase/ERK signaling, and (b) insulin stimulated S100B secretion via PI3K signaling. Our findings indicate the existence of insulin-S100B modulation of glucose utilization in the brain tissue, and may improve our understanding of glucose metabolism in several conditions such as ketosis, streptozotocin-induced dementia and pharmacological exposure to antipsychotics, situations that lead to changes in insulin signaling and extracellular levels of S100B.

Evaluation of cerebral-cardiac syndrome using echocardiography in a canine model of acute traumatic brain injury.

Science.gov (United States)

Qian, Rong; Yang, Weizhong; Wang, Xiumei; Xu, Zhen; Liu, Xiaodong; Sun, Bing

2015-01-01

Previous studies have confirmed that traumatic brain injury (TBI) can induce general adaptation syndrome (GAS), which subsequently results in myocardial dysfunction and damage in some patients with acute TBI; this condition is also termed as cerebral-cardiac syndrome. However, most clinicians ignore the detection and treatment of myocardial dysfunction, and instead concentrate only on the serious neural damage that is observed in acute TBI, which is one of the most important fatal factors. Therefore, clarification is urgently needed regarding the relationship between TBI and myocardial dysfunction. In the present study, we evaluated 18 canine models of acute TBI, by using real-time myocardial contrast echocardiography and strain rate imaging to accurately evaluate myocardial function and regional microcirculation, including the strain rate of the different myocardial segments, time-amplitude curves, mean ascending slope of the curve, and local myocardial blood flow. Our results suggest that acute TBI often results in cerebral-cardiac syndrome, which rapidly progresses to the serious stage within 3 days. This study is the first to provide comprehensive ultrasonic characteristics of cerebral-cardiac syndrome in an animal model of TBI.

Multi-slice CT for visualization of acute pulmonary embolism: single breath-hold subtraction technique

International Nuclear Information System (INIS)

Wildberger, J.E.; Mahnken, A.H.; Spuentrup, E.; Guenther, R.W.; Klotz, E.; Ditt, H.

2005-01-01

Purpose: the purpose of our preliminary animal study was to evaluate the feasibility of a new subtraction technique for visualization of perfusion defects within the lung parenchyma in segmental and subsegmental pulmonary embolism (PE). Materials and methods: in three healthy pigs, PE were artificially induced by fresh human clot material. Within a single breath-hold, CT angiography (CTA) was performed on a 16-slice multi-slice CT scanner (SOMATOM Sensation 16; Siemens, Forchheim, Germany) before and after intravenous application of 80 mL of contrast-medium, followed by a saline chaser. Scan parameters were 120 kV and 100 mAs eff. , using a collimation of 16 x 1.5 mm and a table speed/rot. of 36 mm (pitch: 1.5; rotation time: 0.5 s). A new 3D subtraction technique was developed, which is based on automated segmentation, non-linear spatial filtering and non-rigid registration. Data were analysed using a color-encoded ''compound view'' of parenchymal enhancement and CTA information displayed in axial, coronal and sagittal orientation. Results: subtraction was technically feasible in all three data sets. The mean scan time for each series was 4.7 s, interscan delay was 14.7 s, respectively. Therefore, an average breath-hold of approximately 24 s was required for the overall scanning procedure. Downstream of occluded segmental and subsegmental arteries, perfusion defects were clearly assessable, showing lower or missing enhancement compared to normally perfused lung parenchyma. In all pigs, additional peripheral areas with triangular shaped perfusion defects were delineated, considered typical for PE. Conclusions: our initial results from the animal model studied slow that perfusion imaging of PE is feasible within a single breath-hold. It allows a comprehensive assessment of perfusion deficits as the direct proof of a pulmonary embolus, can be combined with an indirect visual quantification of the density changes in the adjacent lung tissue. (orig.)

Aquaporin-4 deletion in mice reduces encephalopathy and brain edema in experimental acute liver failure.

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Rama Rao, Kakulavarapu V; Verkman, A S; Curtis, Kevin M; Norenberg, Michael D

2014-03-01

Brain edema and associated astrocyte swelling leading to increased intracranial pressure are hallmarks of acute liver failure (ALF). Elevated blood and brain levels of ammonia have been implicated in the development of brain edema in ALF. Cultured astrocytes treated with ammonia have been shown to undergo cell swelling and such swelling was associated with an increase in the plasma membrane expression of aquaporin-4 (AQP4) protein. Further, silencing the AQP4 gene in cultured astrocytes was shown to prevent the ammonia-induced cell swelling. Here, we examined the evolution of brain edema in AQP4-null mice and their wild type counterparts (WT-mice) in different models of ALF induced by thioacetamide (TAA) or acetaminophen (APAP). Induction of ALF with TAA or APAP significantly increased brain water content in WT mice (by 1.6% ± 0.3 and 2.3 ± 0.4%, respectively). AQP4 protein was significantly increased in brain plasma membranes of WT mice with ALF induced by either TAA or APAP. In contrast to WT-mice, brain water content did not increase in AQP4-null mice. Additionally, AQP4-null mice treated with either TAA or APAP showed a remarkably lesser degree of neurological deficits as compared to WT mice; the latter displayed an inability to maintain proper gait, and demonstrated a markedly reduced exploratory behavior, with the mice remaining in one corner of the cage with its head tilted downwards. These results support a central role of AQP4 in the brain edema associated with ALF. Published by Elsevier Inc.

Sensitivity analysis of brain morphometry based on MRI-derived surface models

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Klein, Gregory J.; Teng, Xia; Schoenemann, P. T.; Budinger, Thomas F.

1998-07-01

Quantification of brain structure is important for evaluating changes in brain size with growth and aging and for characterizing neurodegeneration disorders. Previous quantification efforts using ex vivo techniques suffered considerable error due to shrinkage of the cerebrum after extraction from the skull, deformation of slices during sectioning, and numerous other factors. In vivo imaging studies of brain anatomy avoid these problems and allow repetitive studies following progression of brain structure changes due to disease or natural processes. We have developed a methodology for obtaining triangular mesh models of the cortical surface from MRI brain datasets. The cortex is segmented from nonbrain tissue using a 2D region-growing technique combined with occasional manual edits. Once segmented, thresholding and image morphological operations (erosions and openings) are used to expose the regions between adjacent surfaces in deep cortical folds. A 2D region- following procedure is then used to find a set of contours outlining the cortical boundary on each slice. The contours on all slices are tiled together to form a closed triangular mesh model approximating the cortical surface. This model can be used for calculation of cortical surface area and volume, as well as other parameters of interest. Except for the initial segmentation of the cortex from the skull, the technique is automatic and requires only modest computation time on modern workstations. Though the use of image data avoids many of the pitfalls of ex vivo and sectioning techniques, our MRI-based technique is still vulnerable to errors that may impact the accuracy of estimated brain structure parameters. Potential inaccuracies include segmentation errors due to incorrect thresholding, missed deep sulcal surfaces, falsely segmented holes due to image noise and surface tiling artifacts. The focus of this paper is the characterization of these errors and how they affect measurements of cortical surface

Quantitative multivoxel 1H MR spectroscopy of the brain in children with acute liver failure

International Nuclear Information System (INIS)

Sijens, Paul E.; Alkefaji, Heyder; Meiners, Linda C.; Oudkerk, Matthijs; Lunsing, Roelineke J.; Spronsen, Francjan J. van; Verkade, Henkjan J.

2008-01-01

Acute liver failure (ALF)-related encephalopathy was previously characterized by MR spectroscopy of single voxels containing both grey and white matter brain tissue. Quantitative multivoxel MRS was used here to compare grey and white matter brain tissue concentrations of glutamate/glutamine (Glx) and lactate in ALF and associate the results with other liver function parameters. Five pediatric patients with ALF-related encephalopathy and five controls, examined after successful liver transplantation, were examined by brain MRI/MRS. ALF patients had higher Glx and lactate concentrations in brain white matter than controls (Glx + 125%: P < 0.01; lactate + 33%, P < 0.05) and higher Glx in grey matter (Glx + 125%: P < 0.01). Within the group of ALF patients positive correlations were found between grey or white matter lactate concentration and serum ammonia (P < 0.05), and negative correlations between grey or white matter Glx and venous pH (P < 0.001). This is the first study presenting evidence of high Glx levels in both white and grey matter brain tissue in ALF-related encephalopathy. The elevations in CNS Glx and lactate concentrations appear to relate to hepatic detoxification (ammonia, venous pH), rather than to liver parenchymal integrity (aspartate aminotransferase, alanine aminotransferase) or biliary cholestasis (bilirubin, γ-glutamyl transpeptidase, alkaline phosphatase). (orig.)

Diffusion-weighted MR imaging in animal modil with acute ischemic brain infarction : evaluation of reversible brain injury

International Nuclear Information System (INIS)

Byun, Woo Mok; Chang, Han Won; Cho, Inn Ho; Hah, Jung Sang; Sung, Eon Gi

2001-01-01

To determine whether the analysis of abnormally high signal intensities in ischemic tissue, as revealed by diffusion-weighted MR imaging (DWI) can be used to evaluate reversible brain lesions in a cat model of acute ischemia. Ten cats were divided into two groups of five (Group I and Group II), and in all animals the middle cerebral artery was temporarily occluded. Group I underwent T2-DWI 30 minutes after occlusion, and Group II 120 minutes after occlusion. In both groups, DWI was performed one hour and 24 hours after reperfusion (at one hour, non-T2-weighted; at 24 hours, T2-weighted). Both occlusion and reperfusion were monitored by 99m TC-ECD brain perfusion SPECT. All animals were sacrificed 24 hours later and their brain tissue was stained with TTC. Signal intensity ratios (SIR, signifying average signal intensity within the region of interest divided by that in the contralateral, nonischemic, homologous region) of the two groups, as seen on DWI were compared. The percentage of hemispheric lesions occurring in the two groups was also compared. SIR after occlusion of the middle cerebral artery was 1.29 in Group I and 1.59 in Group II. Twenty-four hours after reperfusion, SIR in Group I was higher than in Group II (p<0.01). After occlusion and reperfusion, the percentage of hemispheric lesions in Group I was less than in Group II. For the latter, the percentage of these lesions revealed by TTC staining and T2-weighted imaging was 48% and 59%, respectively, findings distinctly different from those for Group I. In addition, in group I, infarction was revealed by neither TTC staining nor T2-weighted imaging (p<0.01). The use of DWI to evaluate signal intensity ratios can help determine whether or not brain injury after temporary cerebral ischemia is reversible

Temporal Patterns of Soluble Adhesion Molecules in Cerebrospinal Fluid and Plasma in Patients with the Acute Brain Infraction

Directory of Open Access Journals (Sweden)

Vesna Selakovic

2009-01-01

Full Text Available The aim of this study was to define concentration changes of soluble adhesion molecules (sICAM-1, sVCAM-1 and sE-Selectin in cerebrospinal fluid and plasma, as well as, number of peripheral blood leukocytes and the albumin coefficient in the patients with the acute brain infarction. We also, analyzed the correlation between the measured levels, the infarct volume and the degree of neurological and the functional deficit. The study included 50 patients with the acute cerebral infarction and the control group consisted of 16 patients, age and sex matched. Obtained results showed significant increase in number of leukocytes, the albumin coefficient and the level of soluble adhesion molecules within the first seven days in patients. The highest values of measured parameters were noted within the third and the fourth day after the insult, which is the suggested period of maximal intensity of inflammatory reactions. Significant correlation was found between measured parameters and the infarct volume, the degree of neurological and the functional deficit. The results suggest that investigated parameters in CSF and blood represent a dynamic index of inflammatory events as one of the fundametal mechanisms responsible for neuron damage during acute phase of brain infarction.

Neuroprotection from Brain Injury by Novel Estrogens

Science.gov (United States)

2001-08-01

plate contained approxi- substituted estradlol. J. Steroid Blochem. 1988, 29, 657-664. mately 5000 cells as determined by a Neubauer hemacytometer (13...the brain was removed, and the base of the brain was photographed by a digital camera (Sony Preparation of animals MVC-FD5, Tokyo, Japan) for...chloride (TTC) in physiological saline at 37 0 C, and then fixed in 10% formalin. The stained slices were photographed by a digital camera (Sony MVC-FD5

Traumatic Brain Injury Increases Cortical Glutamate Network Activity by Compromising GABAergic Control.

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Cantu, David; Walker, Kendall; Andresen, Lauren; Taylor-Weiner, Amaro; Hampton, David; Tesco, Giuseppina; Dulla, Chris G

2015-08-01

Traumatic brain injury (TBI) is a major risk factor for developing pharmaco-resistant epilepsy. Although disruptions in brain circuitry are associated with TBI, the precise mechanisms by which brain injury leads to epileptiform network activity is unknown. Using controlled cortical impact (CCI) as a model of TBI, we examined how cortical excitability and glutamatergic signaling was altered following injury. We optically mapped cortical glutamate signaling using FRET-based glutamate biosensors, while simultaneously recording cortical field potentials in acute brain slices 2-4 weeks following CCI. Cortical electrical stimulation evoked polyphasic, epileptiform field potentials and disrupted the input-output relationship in deep layers of CCI-injured cortex. High-speed glutamate biosensor imaging showed that glutamate signaling was significantly increased in the injured cortex. Elevated glutamate responses correlated with epileptiform activity, were highest directly adjacent to the injury, and spread via deep cortical layers. Immunoreactivity for markers of GABAergic interneurons were significantly decreased throughout CCI cortex. Lastly, spontaneous inhibitory postsynaptic current frequency decreased and spontaneous excitatory postsynaptic current increased after CCI injury. Our results suggest that specific cortical neuronal microcircuits may initiate and facilitate the spread of epileptiform activity following TBI. Increased glutamatergic signaling due to loss of GABAergic control may provide a mechanism by which TBI can give rise to post-traumatic epilepsy. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Venous or arterial blood components trigger more brain swelling, tissue death after acute subdural hematoma compared to elderly atrophic brain with subdural effusion (SDE) model rats.

Science.gov (United States)

Wajima, Daisuke; Sato, Fumiya; Kawamura, Kenya; Sugiura, Keisuke; Nakagawa, Ichiro; Motoyama, Yasushi; Park, Young-Soo; Nakase, Hiroyuki

2017-09-01

Acute subdural hematoma (ASDH) is a frequent complication of severe head injury, whose secondary ischemic lesions are often responsible for the severity of the disease. We focused on the differences of secondary ischemic lesions caused by the components, 0.4ml venous- or arterial-blood, or saline, infused in the subdural space, evaluating the differences in vivo model, using rats. The saline infused rats are made for elderly atrophic brain with subdural effusion (SDE) model. Our data showed that subdural blood, both venous- and arterial-blood, aggravate brain edema and lesion development more than SDE. This study is the first study, in which different fluids in rats' subdural space, ASDH or SDE are compared with the extension of early and delayed brain damage by measuring brain edema and histological lesion volume. Blood constituents started to affect the degree of ischemia underneath the subdural hemorrhage, leading to more pronounced breakdown of the blood-brain barrier and brain damage. This indicates that further strategies to treat blood-dependent effects more efficiently are in view for patients with ASDH. Copyright © 2017 Elsevier B.V. All rights reserved.

Introduction to bit slices and microprogramming

International Nuclear Information System (INIS)

Van Dam, A.

1981-01-01

Bit-slice logic blocks are fourth-generation LSI components which are natural extensions of traditional mulitplexers, registers, decoders, counters, ALUs, etc. Their functionality is controlled by microprogramming, typically to implement CPUs and peripheral controllers where both speed and easy programmability are required for flexibility, ease of implementation and debugging, etc. Processors built from bit-slice logic give the designer an alternative for approaching the programmibility of traditional fixed-instruction-set microprocessors with a speed closer to that of hardwired random logic. (orig.)

Gravitational collapse of charged dust shell and maximal slicing condition

International Nuclear Information System (INIS)

Maeda, Keiichi

1980-01-01

The maximal slicing condition is a good time coordinate condition qualitatively when pursuing the gravitational collapse by the numerical calculation. The analytic solution of the gravitational collapse under the maximal slicing condition is given in the case of a spherical charged dust shell and the behavior of time slices with this coordinate condition is investigated. It is concluded that under the maximal slicing condition we can pursue the gravitational collapse until the radius of the shell decreases to about 0.7 x (the radius of the event horizon). (author)

Preservation of low slice emittance in bunch compressors

Directory of Open Access Journals (Sweden)

S. Bettoni

2016-03-01

Full Text Available Minimizing the dilution of the electron beam emittance is crucial for the performance of accelerators, in particular for free electron laser facilities, where the length of the machine and the efficiency of the lasing process depend on it. Measurements performed at the SwissFEL Injector Test Facility revealed an increase in slice emittance after compressing the bunch even for moderate compression factors. The phenomenon was experimentally studied by characterizing the dependence of the effect on beam and machine parameters relevant for the bunch compression. The reproduction of these measurements in simulation required the use of a 3D beam dynamics model along the bunch compressor that includes coherent synchrotron radiation. Our investigations identified transverse effects, such as coherent synchrotron radiation and transverse space charge as the sources of the observed emittance dilution, excluding other effects, such as chromatic effects on single slices or spurious dispersion. We also present studies, both experimental and simulation based, on the effect of the optics mismatch of the slices on the variation of the slice emittance along the bunch. After a corresponding reoptimization of the beam optics in the test facility we reached slice emittances below 200 nm for the central slices along the longitudinal dimension with a moderate increase up to 300 nm in the head and tail for a compression factor of 7.5 and a bunch charge of 200 pC, equivalent to a final current of 150 A, at about 230 MeV energy.

Brain-Derived Neurotrophic Factor in TBI-related mortality: Interrelationships between Genetics and Acute Systemic and CNS BDNF Profiles

Science.gov (United States)

Failla, Michelle D.; Conley, Yvette P.; Wagner, Amy K.

2015-01-01

Background Older adults have higher mortality rates after severe traumatic brain injury (TBI) compared to younger adults. Brain derived neurotrophic factor (BDNF) signaling is altered in aging and is important to TBI given its role in neuronal survival/plasticity and autonomic function. Following experimental TBI, acute BDNF administration has not been efficacious. Clinically, genetic variation in BDNF (reduced signaling alleles: rs6265, Met-carriers; rs7124442, C-carriers) were protective in acute mortality. Post-acutely, these genotypes carried lower mortality risk in older adults, and greater mortality risk among younger adults. Objective Investigate BDNF levels in mortality/outcome following severe TBI in the context of age and genetic risk. Methods CSF and serum BDNF were assessed prospectively during the first week following severe TBI (n=203), and in controls (n=10). Age, BDNF genotype, and BDNF levels were assessed as mortality/outcome predictors. Results CSF BDNF levels tended to be higher post-TBI (p=0.061) versus controls and were associated with time until death (p=0.042). In contrast, serum BDNF levels were reduced post-TBI versus controls (pBDNF serum and gene*age interactions were mortality predictors post-TBI in the same multivariate model. CSF and serum BDNF tended to be negatively correlated post-TBI (p=0.07). Conclusions BDNF levels predicted mortality, in addition to gene*age interactions, suggesting levels capture additional mortality risk. Higher CSF BDNF post-TBI may be detrimental due to injury and age-related increases in pro-apoptotic BDNF target receptors. Negative CSF and serum BDNF correlations post-TBI suggest blood-brain barrier transit alterations. Understanding BDNF signaling in neuronal survival, plasticity, and autonomic function may inform treatment. PMID:25979196

Tumor Slice Culture: A New Avatar in Personalized Oncology

Science.gov (United States)

2017-09-01

AWARD NUMBER: W81XWH-16-1-0149 TITLE: Tumor Slice Culture: A New Avatar in Personalized Oncology PRINCIPAL INVESTIGATOR: Raymond Yeung...CONTRACT NUMBER Tumor Slice Culture: A New Avatar in Personalized Oncology 5b. GRANT NUMBER W81XWH-16-1-0149 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...10 Annual Report 2017: Tumor Slice Culture: A new avatar for personalized oncology 1. INTRODUCTION: The goal of this research is to advance our

Visualization and volumetric structures from MR images of the brain

Energy Technology Data Exchange (ETDEWEB)

Parvin, B.; Johnston, W.; Robertson, D.

1994-03-01

Pinta is a system for segmentation and visualization of anatomical structures obtained from serial sections reconstructed from magnetic resonance imaging. The system approaches the segmentation problem by assigning each volumetric region to an anatomical structure. This is accomplished by satisfying constraints at the pixel level, slice level, and volumetric level. Each slice is represented by an attributed graph, where nodes correspond to regions and links correspond to the relations between regions. These regions are obtained by grouping pixels based on similarity and proximity. The slice level attributed graphs are then coerced to form a volumetric attributed graph, where volumetric consistency can be verified. The main novelty of our approach is in the use of the volumetric graph to ensure consistency from symbolic representations obtained from individual slices. In this fashion, the system allows errors to be made at the slice level, yet removes them when the volumetric consistency cannot be verified. Once the segmentation is complete, the 3D surfaces of the brain can be constructed and visualized.

Readmission to Acute Care Hospital during Inpatient Rehabilitation for Traumatic Brain Injury

Science.gov (United States)

Hammond, Flora M.; Horn, Susan D.; Smout, Randall J.; Beaulieu, Cynthia L.; Barrett, Ryan S.; Ryser, David K.; Sommerfeld, Teri

2015-01-01

Objective To investigate frequency, reasons, and factors associated with readmission to acute care (RTAC) during inpatient rehabilitation for traumatic brain injury (TBI). Design Prospective observational cohort. Setting Inpatient rehabilitation. Participants 2,130 consecutive admissions for TBI rehabilitation. Interventions Not applicable. Main Outcome Measure(s) RTAC incidence, RTAC causes, rehabilitation length of stay (RLOS), and rehabilitation discharge location. Results 183 participants (9%) experienced RTAC for a total 210 episodes. 161 patients experienced 1 RTAC episode, 17 had 2, and 5 had 3. Mean days from rehabilitation admission to first RTAC was 22 days (SD 22). Mean duration in acute care during RTAC was 7 days (SD 8). 84 participants (46%) had >1 RTAC episode for medical reasons, 102 (56%) had >1 RTAC for surgical reasons, and RTAC reason was unknown for 6 (3%) participants. Most common surgical RTAC reasons were: neurosurgical (65%), pulmonary (9%), infection (5%), and orthopedic (5%); most common medical reasons were infection (26%), neurologic (23%), and cardiac (12%). Older age, history of coronary artery disease, history of congestive heart failure, acute care diagnosis of depression, craniotomy or craniectomy during acute care, and presence of dysphagia at rehabilitation admission predicted patients with RTAC. RTAC was less likely for patients with higher admission Functional Independence Measure Motor scores and education less than high school diploma. RTAC occurrence during rehabilitation was significantly associated with longer RLOS and smaller likelihood of discharge home. Conclusion(s) Approximately 9% of patients with TBI experience RTAC during inpatient rehabilitation for various medical and surgical reasons. This information may help inform interventions aimed at reducing interruptions in rehabilitation due to RTAC. RTACs were associated with longer RLOS and discharge to an institutional setting. PMID:26212405

Brain hypoxia imaging

Energy Technology Data Exchange (ETDEWEB)

Song, Ho Chun [Chonnam National University Medical School, Gwangju (Korea, Republic of)

2007-04-15

The measurement of pathologically low levels of tissue pO{sub 2} is an important diagnostic goal for determining the prognosis of many clinically important diseases including cardiovascular insufficiency, stroke and cancer. The target tissues nowadays have mostly been tumors or the myocardium, with less attention centered on the brain. Radiolabelled nitroimidazole or derivatives may be useful in identifying the hypoxic cells in cerebrovascular disease or traumatic brain injury, and hypoxic-ischemic encephalopathy. In acute stroke, the target of therapy is the severely hypoxic but salvageable tissue. {sup 18}F-MISO PET and {sup 99m}Tc-EC-metronidazole SPECT in patients with acute ischemic stroke identified hypoxic tissues and ischemic penumbra, and predicted its outcome. A study using {sup 123}I-IAZA in patient with closed head injury detected the hypoxic tissues after head injury. Up till now these radiopharmaceuticals have drawbacks due to its relatively low concentration with hypoxic tissues associated with/without low blood-brain barrier permeability and the necessity to wait a long time to achieve acceptable target to background ratios for imaging in acute ischemic stroke. It is needed to develop new hypoxic marker exhibiting more rapid localization in the hypoxic region in the brain. And then, the hypoxic brain imaging with imidazoles or non-imidazoles may be very useful in detecting the hypoxic tissues, determining therapeutic strategies and developing therapeutic drugs in several neurological disease, especially, in acute ischemic stroke.

Increased toll-like receptor 4 in cerebral endothelial cells contributes to the astrocyte swelling and brain edema in acute hepatic encephalopathy.

Science.gov (United States)

Jayakumar, Arumugam R; Tong, Xiao Y; Curtis, Kevin M; Ruiz-Cordero, Roberto; Abreu, Maria T; Norenberg, Michael D

2014-03-01

Astrocyte swelling and the subsequent increase in intracranial pressure and brain herniation are major clinical consequences in patients with acute hepatic encephalopathy. We recently reported that conditioned media from brain endothelial cells (ECs) exposed to ammonia, a mixture of cytokines (CKs) or lipopolysaccharide (LPS), when added to astrocytes caused cell swelling. In this study, we investigated the possibility that ammonia and inflammatory agents activate the toll-like receptor 4 (TLR4) in ECs, resulting in the release of factors that ultimately cause astrocyte swelling. We found a significant increase in TLR4 protein expression when ECs were exposed to ammonia, CKs or LPS alone, while exposure of ECs to a combination of these agents potentiate such effects. In addition, astrocytes exposed to conditioned media from TLR4-silenced ECs that were treated with ammonia, CKs or LPS, resulted in a significant reduction in astrocyte swelling. TLR4 protein up-regulation was also detected in rat brain ECs after treatment with the liver toxin thioacetamide, and that thioacetamide-treated TLR4 knock-out mice exhibited a reduction in brain edema. These studies strongly suggest that ECs significantly contribute to the astrocyte swelling/brain edema in acute hepatic encephalopathy, likely as a consequence of increased TLR4 protein expression by blood-borne noxious agents. © 2013 International Society for Neurochemistry.

High-resolution whole-brain diffusion MRI at 7T using radiofrequency parallel transmission.

Science.gov (United States)

Wu, Xiaoping; Auerbach, Edward J; Vu, An T; Moeller, Steen; Lenglet, Christophe; Schmitter, Sebastian; Van de Moortele, Pierre-François; Yacoub, Essa; Uğurbil, Kâmil

2018-03-30

Investigating the utility of RF parallel transmission (pTx) for Human Connectome Project (HCP)-style whole-brain diffusion MRI (dMRI) data at 7 Tesla (7T). Healthy subjects were scanned in pTx and single-transmit (1Tx) modes. Multiband (MB), single-spoke pTx pulses were designed to image sagittal slices. HCP-style dMRI data (i.e., 1.05-mm resolutions, MB2, b-values = 1000/2000 s/mm 2 , 286 images and 40-min scan) and data with higher accelerations (MB3 and MB4) were acquired with pTx. pTx significantly improved flip-angle detected signal uniformity across the brain, yielding ∼19% increase in temporal SNR (tSNR) averaged over the brain relative to 1Tx. This allowed significantly enhanced estimation of multiple fiber orientations (with ∼21% decrease in dispersion) in HCP-style 7T dMRI datasets. Additionally, pTx pulses achieved substantially lower power deposition, permitting higher accelerations, enabling collection of the same data in 2/3 and 1/2 the scan time or of more data in the same scan time. pTx provides a solution to two major limitations for slice-accelerated high-resolution whole-brain dMRI at 7T; it improves flip-angle uniformity, and enables higher slice acceleration relative to current state-of-the-art. As such, pTx provides significant advantages for rapid acquisition of high-quality, high-resolution truly whole-brain dMRI data. © 2018 International Society for Magnetic Resonance in Medicine.

Brain-Derived Neurotrophic Factor (BDNF) in Traumatic Brain Injury-Related Mortality: Interrelationships Between Genetics and Acute Systemic and Central Nervous System BDNF Profiles.

Science.gov (United States)

Failla, Michelle D; Conley, Yvette P; Wagner, Amy K

2016-01-01

Older adults have higher mortality rates after severe traumatic brain injury (TBI) compared to younger adults. Brain-derived neurotrophic factor (BDNF) signaling is altered in aging and is important to TBI given its role in neuronal survival/plasticity and autonomic function. Following experimental TBI, acute BDNF administration has not been efficacious. Clinically, genetic variation in BDNF (reduced signaling alleles: rs6265, Met-carriers; rs7124442, C-carriers) can be protective against acute mortality. Postacutely, these genotypes carry lower mortality risk in older adults and greater mortality risk among younger adults. Investigate BDNF levels in mortality/outcome following severe TBI in the context of age and genetic risk. Cerebrospinal fluid (CSF) and serum BDNF were assessed prospectively during the first week following severe TBI (n = 203) and in controls (n = 10). Age, BDNF genotype, and BDNF levels were assessed as mortality/outcome predictors. CSF BDNF levels tended to be higher post-TBI (P = .061) versus controls and were associated with time until death (P = .042). In contrast, serum BDNF levels were reduced post-TBI versus controls (P BDNF serum and gene * age interactions were mortality predictors post-TBI in the same multivariate model. CSF and serum BDNF tended to be negatively correlated post-TBI (P = .07). BDNF levels predicted mortality, in addition to gene * age interactions, suggesting levels capture additional mortality risk. Higher CSF BDNF post-TBI may be detrimental due to injury and age-related increases in pro-apoptotic BDNF target receptors. Negative CSF and serum BDNF correlations post-TBI suggest blood-brain barrier transit alterations. Understanding BDNF signaling in neuronal survival, plasticity, and autonomic function may inform treatment. © The Author(s) 2015.

Single-nanotube tracking reveals the nanoscale organization of the extracellular space in the live brain

Science.gov (United States)

Godin, Antoine G.; Varela, Juan A.; Gao, Zhenghong; Danné, Noémie; Dupuis, Julien P.; Lounis, Brahim; Groc, Laurent; Cognet, Laurent

2017-03-01

The brain is a dynamic structure with the extracellular space (ECS) taking up almost a quarter of its volume. Signalling molecules, neurotransmitters and nutrients transit via the ECS, which constitutes a key microenvironment for cellular communication and the clearance of toxic metabolites. The spatial organization of the ECS varies during sleep, development and aging and is probably altered in neuropsychiatric and degenerative diseases, as inferred from electron microscopy and macroscopic biophysical investigations. Here we show an approach to directly observe the local ECS structures and rheology in brain tissue using super-resolution imaging. We inject single-walled carbon nanotubes into rat cerebroventricles and follow the near-infrared emission of individual nanotubes as they diffuse inside the ECS for tens of minutes in acute slices. Because of the interplay between the nanotube geometry and the ECS local environment, we can extract information about the dimensions and local viscosity of the ECS. We find a striking diversity of ECS dimensions down to 40 nm, and as well as of local viscosity values. Moreover, by chemically altering the extracellular matrix of the brains of live animals before nanotube injection, we reveal that the rheological properties of the ECS are affected, but these alterations are local and inhomogeneous at the nanoscale.

Preliminary Study of Realistic Blast Impact on Cultured Brain Slices

Science.gov (United States)

2015-04-01

Duhaime A, Bullock R, Maas A, Valadka A, Manley G. Classification of traumatic brain injury for targeted therapies. J Neurotrauma. 2008;25:719–738...RDRL CIO LL IMAL HRA MAIL & RECORDS MGMT 1 GOVT PRINTG OFC (PDF) A MALHOTRA 6 DIR USARL (PDF) RDRL WML C S AUBERT R BENJAMIN

Autoradiographic visualization of insulin-like growth factor-II receptors in rat brain

International Nuclear Information System (INIS)

Mendelsohn, L.G.; Kerchner, G.A.; Clemens, J.A.; Smith, M.C.

1986-01-01

The documented presence of IGF-II in brain and CSF prompted us to investigate the distribution of receptors for IGF-II in rat brain slices. Human 125 -I-IGF-II (10 pM) was incubated for 16 hrs at 4 0 C with slide-mounted rat brain slices in the absence and presence of unlabeled human IGF-II (67 nM) or human insulin (86 nM). Slides were washed, dried, and exposed to X-ray film for 4-7 days. The results showed dense labeling in the granular layers of the olfactory bulbs, deep layers of the cerebral cortex, pineal gland, anterior pituitary, hippocampus (pyramidal cells CA 1 -CA 2 and dentate gyrus), and the granule cell layers of the cerebellum. Unlabeled IGF-II eliminated most of the binding of these brain regions while insulin produced only a minimal reduction in the amount of 125 I-IGF-II bound. These results indicate that a specific neural receptor for IGS-II is uniquely distributed in rat brain tissue and supports the notion that this peptide might play an important role in normal neuronal functioning

Is There Hope? Is She There? How Families and Clinicians Experience Severe Acute Brain Injury.

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Schutz, Rachael E C; Coats, Heather L; Engelberg, Ruth A; Curtis, J Randall; Creutzfeldt, Claire J

2017-02-01

Patients with severe acute brain injury (SABI) raise important palliative care considerations associated with sudden devastating injury and uncertain prognosis. The goal of this study was to explore how family members, nurses, and physicians experience the palliative and supportive care needs of patients with SABI receiving care in the neuroscience intensive care unit (neuro-ICU). Semistructured interviews were audiotaped, transcribed, and analyzed using thematic analysis. Thirty-bed neuro-ICU in a regional comprehensive stroke and level-one trauma center in the United States. We completed 47 interviews regarding 15 patients with family members (n = 16), nurses (n = 15), and physicians (n = 16). Two themes were identified: (1) hope and (2) personhood. (1) Families linked prognostic uncertainty to a need for hope and expressed a desire for physicians to acknowledge this relationship. The language of hope varied depending on the participant: clinicians used hope as an object that can be given or taken away, generally in the process of conveying prognosis, while families expressed hope as an action that supported coping with their loved one's acute illness and its prognostic uncertainty. (2) Participants described the loss of personhood through brain injury, the need to recognize and treat the brain-injured patient as a person, and the importance of relatedness and connection, including personal support of families by clinicians. Support for hope and preservation of personhood challenge care in the neuro-ICU as identified by families and clinicians of patients with SABI. Specific practical approaches can address these challenges and improve the palliative care provided to patients and families in the neuro-ICU.

A simple method for multiday imaging of slice cultures.

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Seidl, Armin H; Rubel, Edwin W

2010-01-01

The organotypic slice culture (Stoppini et al. A simple method for organotypic cultures of nervous tissue. 1991;37:173-182) has become the method of choice to answer a variety of questions in neuroscience. For many experiments, however, it would be beneficial to image or manipulate a slice culture repeatedly, for example, over the course of many days. We prepared organotypic slice cultures of the auditory brainstem of P3 and P4 mice and kept them in vitro for up to 4 weeks. Single cells in the auditory brainstem were transfected with plasmids expressing fluorescent proteins by way of electroporation (Haas et al. Single-cell electroporation for gene transfer in vivo. 2001;29:583-591). The culture was then placed in a chamber perfused with oxygenated ACSF and the labeled cell imaged with an inverted wide-field microscope repeatedly for multiple days, recording several time-points per day, before returning the slice to the incubator. We describe a simple method to image a slice culture preparation during the course of multiple days and over many continuous hours, without noticeable damage to the tissue or photobleaching. Our method uses a simple, inexpensive custom-built insulator constructed around the microscope to maintain controlled temperature and uses a perfusion chamber as used for in vitro slice recordings. (c) 2009 Wiley-Liss, Inc.

Intrinsic control of electroresponsive properties of transplanted mammalian brain neurons

DEFF Research Database (Denmark)

Hounsgaard, J; Yarom, Y

1985-01-01

The present study presents the first analysis of neurons in mammalian brain transplants based on intracellular recording. The results, obtained in brain slices including both donor and host tissue, showed that neuronal precursor cells in embryonic transplants retained their ability to complete...... their normal differentiation of cell-type-specific electroresponsive properties. Distortions in cell aggregation and synaptic connectivity did not affect this aspect of neuronal differentiation....

Evaluating acute effects of Electro Convulsive Therapy (ECT) on brain perfusion with Tc-99m HMPAO brain SPECT

International Nuclear Information System (INIS)

Ozguven, M.; Ozturk, E.; Gunalp, B.; Ozgen, F.; Bayhan, H.

1992-01-01

Regional cerebral blood flow (rCBF) was measured by Tc-99m HMPAO brain perfusion SPECT in 10 schizophrenes (8 male, 2 female) undergoing electro convulsive therapy (ECT) and the results were compared to those of baseline studies performed 3 days prior to the ECT application to evaluate its acute effect on brain perfusion. ECT caused a redistribution in the tracers uptake. There was a global increase in the rCBF and the uptake became more pronounced in the basal ganglia (left: 44.4+-1.9%, right: 43.1+-19%) and to a degree in the parietal (left: 26.5+-4.1%, right: 25+-3.4%) and temporal (left: 22.9+-4.3%, right: 22.3+-3.6%) cortices. When evaluating the effects of ECT on rCBF, factors like the used perfusion agent, the injection and rCBF measurement times, clinical status of the patient, duration of the illness, used therapeutic agents and variations in the ECT application should be taken into consideration because the obtained data may reflect either the ictal or post-ictal changes on rCBF and is specific to the group of patients undergoing the study

Effects of Acute Toluene Toxicity on Different Regions of Rabbit Brain

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Mehmet Demır

2017-01-01

Full Text Available The acute phase effects of toluene on the brain have been investigated in this study using rabbit brain via histopathological, immunohistochemical, and biochemical methods. A total of 20 male rabbits were used as control and experimental groups. Moreover, nerve growth factor (NGF, tumor necrosis factor-alpha (TNF-alpha, dopamine (DA, and glial fibrillary acidic protein (GFAP tests were performed in order to designate the severity of the biochemical damage. In the biochemical evaluation of the prefrontal cortex, hippocampus, hypothalamus, substantia nigra, and entorhinal cortex, the TNF-alpha levels in the brain were found to be significantly higher than in the control group. Levels of dopamine, secreted from the substantia nigra, nerve growth factor (NGF developed from the hippocampal neurons, and GFAP, secreted from astrocyte cells, were detected to be significantly lower in the toluene-administration group than in the control group (p<0.05. In addition, areas of focal vacuolar degeneration (abscess formation, gliosis, and perivascular demyelination, many pyknotic cells and necrosis were observed. In the toluene-administration group compared to the control group, distinct excessive expansions of the blood vessels and severe degeneration in the structure of cells and also dispersed cell borders were observed. Furthermore, abnormal malformations of the nuclei structure of the oligodendrocyte cells were seen. Bodies of the sequential neurons of the hippocampus in the toluene-administration group were distinctly structurally damaged compared to the control group. In addition, cytoplasm of the cortex cell showed serious immune reactivity in the experimental group.

Central Administration of Lipopolysaccharide Induces Depressive-like Behavior in Vivo and Activates Brain Indoleamine 2,3 Dioxygenase In Murine Organotypic Hippocampal Slice Cultures

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Kavelaars Annemieke

2010-08-01

Full Text Available Abstract Background Transient stimulation of the innate immune system by an intraperitoneal injection of lipopolysaccharide (LPS activates peripheral and central expression of the tryptophan degrading enzyme indoleamine 2,3 dioxygenase (IDO which mediates depressive-like behavior. It is unknown whether direct activation of the brain with LPS is sufficient to activate IDO and induce depressive-like behavior. Methods Sickness and depressive-like behavior in C57BL/6J mice were assessed by social exploration and the forced swim test, respectively. Expression of cytokines and IDO mRNA was measured by real-time RT-PCR and cytokine protein was measured by enzyme-linked immunosorbent assays (ELISAs. Enzymatic activity of IDO was estimated as the amount of kynurenine produced from tryptophan as determined by high pressure liquid chromatography (HPLC with electrochemical detection. Results Intracerebroventricular (i.c.v. administration of LPS (100 ng increased steady-state transcripts of TNFα, IL-6 and the inducible isoform of nitric oxide synthase (iNOS in the hippocampus in the absence of any change in IFNγ mRNA. LPS also increased IDO expression and induced depressive-like behavior, as measured by increased duration of immobility in the forced swim test. The regulation of IDO expression was investigated using in situ organotypic hippocampal slice cultures (OHSCs derived from brains of newborn C57BL/6J mice. In accordance with the in vivo data, addition of LPS (10 ng/ml to the medium of OHSCs induced steady-state expression of mRNA transcripts for IDO that peaked at 6 h and translated into increased IDO enzymatic activity within 8 h post-LPS. This activation of IDO by direct application of LPS was preceded by synthesis and secretion of TNFα and IL-6 protein and activation of iNOS while IFNγ expression was undetectable. Conclusion These data establish that activation of the innate immune system in the brain is sufficient to activate IDO and induce

Technetium-99m HMPAO SPET in acute supratentorial ischaemic infraction, expressing deficits as millilitre of zero perfusion

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Dierckx, R.A. [Univ. Hospital of Ghent (Belgium). Dept. of Nuclear Medicine and Radiotherapy]|[Antwerp Univ. (Belgium). Lab. of Neurochemistry and Behavior, Born-Bunge Foundation UIA; Dobbeleir, A. [Middelheim Hospital, Antwerp (Belgium). Dept. of Nuclear Medicine; Pickut, B.A. [Middelheim Hospital, Antwerp (Belgium). Dept. of Neurology; Timmermans, L. [Middelheim Hospital, Antwerp (Belgium). Dept. of Neurology; Dierckx, I. [Middelheim Hospital, Antwerp (Belgium). Dept. of Radiology; Vervaet, A. [Middelheim Hospital, Antwerp (Belgium). Dept. of Nuclear Medicine; Vandevivere, J. [Middelheim Hospital, Antwerp (Belgium). Dept. of Nuclear Medicine; Deberdt, W. [UCB Pharma NV (Belgium); Deyn, P.P. de [Middelheim Hospital, Antwerp (Belgium). Dept. of Neurology]|[Antwerp Univ. (Belgium). Lab. of Neurochemistry and Behavior, Born-Bunge Foundation UIA

1995-05-01

A comparative interim analysis was performed of clinical parameters, computed tomographic (CT) scan results and {sup 99m}Tc-HMPAO (SPET)-findings obtained within 12 h of acute supratentorial ischaemic infarction. First, the applicability for SPET semiquantification in this study of the ``method of Mountz``, simultaneously accounting for extent and degrees of hypoperfusion, was considered. Next, the relative contributions of perfusion SPET and CT scan in the acute stage of ischaemic infarction were compared in 27 patients (mean age 68.8 years). Finally, the correlation of SPET lesions with clinical parameters at onset was evaluated. The method of Mountz represents a workable, accurate virtual parameter, with the assumption that the contralateral brain region remains uninvolved. Because of inconstant distribution of activities in the brain, the method can only be applied slice by sclice and not on the total global volume. While the mean delay since the onset of symptomatology was approximately 7 h for both SPET and CT scan, SPET showed lesions concordant with the clinical neurological findings in 100% and CT scan in only 48%. One could hypothesize that SPET examinations performed later would show larger functional defects, because of the development of additional functional changes secondary to biochemical alterations. However, in this regard no statistically significant differences were found between two subproups, taking the median of delay before SPET examination as cut-off. Finally, when comparing the volumes of SPET lesions during the acute stage with clinical parameters, a statistically significant correlation (P<0.01) was found with the Orgogozo Scale scores describing the neurological deficit, but not with the Glasgow Coma Scale or Frenchay Aphasia Screening Test scores obtained on admittance. (orig./MG)

Technetium-99m HMPAO SPET in acute supratentorial ischaemic infraction, expressing deficits as millilitre of zero perfusion

International Nuclear Information System (INIS)

Dierckx, R.A.; Deyn, P.P. de; Antwerp Univ.

1995-01-01

A comparative interim analysis was performed of clinical parameters, computed tomographic (CT) scan results and 99m Tc-HMPAO (SPET)-findings obtained within 12 h of acute supratentorial ischaemic infarction. First, the applicability for SPET semiquantification in this study of the ''method of Mountz'', simultaneously accounting for extent and degrees of hypoperfusion, was considered. Next, the relative contributions of perfusion SPET and CT scan in the acute stage of ischaemic infarction were compared in 27 patients (mean age 68.8 years). Finally, the correlation of SPET lesions with clinical parameters at onset was evaluated. The method of Mountz represents a workable, accurate virtual parameter, with the assumption that the contralateral brain region remains uninvolved. Because of inconstant distribution of activities in the brain, the method can only be applied slice by sclice and not on the total global volume. While the mean delay since the onset of symptomatology was approximately 7 h for both SPET and CT scan, SPET showed lesions concordant with the clinical neurological findings in 100% and CT scan in only 48%. One could hypothesize that SPET examinations performed later would show larger functional defects, because of the development of additional functional changes secondary to biochemical alterations. However, in this regard no statistically significant differences were found between two subproups, taking the median of delay before SPET examination as cut-off. Finally, when comparing the volumes of SPET lesions during the acute stage with clinical parameters, a statistically significant correlation (P<0.01) was found with the Orgogozo Scale scores describing the neurological deficit, but not with the Glasgow Coma Scale or Frenchay Aphasia Screening Test scores obtained on admittance. (orig./MG)

Bilirubin and its oxidation products damage brain white matter

Science.gov (United States)

Lakovic, Katarina; Ai, Jinglu; D'Abbondanza, Josephine; Tariq, Asma; Sabri, Mohammed; Alarfaj, Abdullah K; Vasdev, Punarjot; Macdonald, Robert Loch

2014-01-01

Brain injury after intracerebral hemorrhage (ICH) occurs in cortex and white matter and may be mediated by blood breakdown products, including hemoglobin and heme. Effects of blood breakdown products, bilirubin and bilirubin oxidation products, have not been widely investigated in adult brain. Here, we first determined the effect of bilirubin and its oxidation products on the structure and function of white matter in vitro using brain slices. Subsequently, we determined whether these compounds have an effect on the structure and function of white matter in vivo. In all, 0.5 mmol/L bilirubin treatment significantly damaged both the function and the structure of myelinated axons but not the unmyelinated axons in brain slices. Toxicity of bilirubin in vitro was prevented by dimethyl sulfoxide. Bilirubin oxidation products (BOXes) may be responsible for the toxicity of bilirubin. In in vivo experiments, unmyelinated axons were found more susceptible to damage from bilirubin injection. These results suggest that unmyelinated axons may have a major role in white-matter damage in vivo. Since bilirubin and BOXes appear in a delayed manner after ICH, preventing their toxic effects may be worth investigating therapeutically. Dimethyl sulfoxide or its structurally related derivatives may have a potential therapeutic value at antagonizing axonal damage after hemorrhagic stroke. PMID:25160671

Cholinesterase modulations in patients with acute bacterial meningitis

DEFF Research Database (Denmark)

Berg, Ronan M G; Ofek, Keren; Qvist, Tavs

2011-01-01

The circulating cholinesterases acetyl- and butyrylcholinesterase may be suppressed and subsequently released from the brain in acute bacterial meningitis.......The circulating cholinesterases acetyl- and butyrylcholinesterase may be suppressed and subsequently released from the brain in acute bacterial meningitis....

Relationship of radiation dose and spiral pitch for multi-slice CT system

International Nuclear Information System (INIS)

Song Shaojuan; Wang Wei; Liu Chuanya

2006-01-01

Objective: To study the relations of radiation dose and spiral pitch for multi-slice CT system. Methods: 16 mm dose phantom with solidose 300/400 pen-style ion chamber inserted into each of five holes in turn was scanned with different spiral pitch by LightSpeed 16-slice CT and Sensation 16-slice and 64-slice CT and radiation dose. Results: CTDI vol of axial scan and spiral scan for the three types of CT system are: (1) LightSpeed 16-slice CT: 28.9 (axial), 51.4 (pitch 0.562), 30.8 (pitch 0.938) and 16.5 ( pitch 1.75 ); (2) Sensation 16-slice CT: 41.2(axial) and 40.3(pitch 0.5) ,41.5(pitch 1) and 43.2(pitch 1.5); (3) Sensation 64- slice CT: 41.2(axial) and 40.3(pitch 0.5),41.5(pitch 1),43.2(pitch 1.5). Conclusions: For LightSpeed 16-slice CT, the measured radiation dose decreased with the increase of spiral pitch, the image quality could keep constant only if we increase mAs. While for Sensation 16-slice and 64-slice CT system, the measured radiation dose was identical for different pitch, and the image quality was identical because of the use of mAs auto control technique The mAs should be adjusted in different way according to the type of CT system when the pitch is changed in daily operation. (authors)

Quantitative multivoxel {sup 1}H MR spectroscopy of the brain in children with acute liver failure

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Sijens, Paul E.; Alkefaji, Heyder; Meiners, Linda C.; Oudkerk, Matthijs [University Medical Center Groningen and University of Groningen, Department of Radiology, Beatrix Children' s Hospital, Groningen (Netherlands); Lunsing, Roelineke J. [University Medical Center Groningen and University of Groningen, Department of Child Neurology, Beatrix Children' s Hospital, Groningen (Netherlands); Spronsen, Francjan J. van; Verkade, Henkjan J. [University Medical Center Groningen and University of Groningen, Department of Pediatrics, Beatrix Children' s Hospital, Groningen (Netherlands)

2008-11-15

Acute liver failure (ALF)-related encephalopathy was previously characterized by MR spectroscopy of single voxels containing both grey and white matter brain tissue. Quantitative multivoxel MRS was used here to compare grey and white matter brain tissue concentrations of glutamate/glutamine (Glx) and lactate in ALF and associate the results with other liver function parameters. Five pediatric patients with ALF-related encephalopathy and five controls, examined after successful liver transplantation, were examined by brain MRI/MRS. ALF patients had higher Glx and lactate concentrations in brain white matter than controls (Glx + 125%: P < 0.01; lactate + 33%, P < 0.05) and higher Glx in grey matter (Glx + 125%: P < 0.01). Within the group of ALF patients positive correlations were found between grey or white matter lactate concentration and serum ammonia (P < 0.05), and negative correlations between grey or white matter Glx and venous pH (P < 0.001). This is the first study presenting evidence of high Glx levels in both white and grey matter brain tissue in ALF-related encephalopathy. The elevations in CNS Glx and lactate concentrations appear to relate to hepatic detoxification (ammonia, venous pH), rather than to liver parenchymal integrity (aspartate aminotransferase, alanine aminotransferase) or biliary cholestasis (bilirubin, {gamma}-glutamyl transpeptidase, alkaline phosphatase). (orig.)

Generalized Fourier slice theorem for cone-beam image reconstruction.

Science.gov (United States)

Zhao, Shuang-Ren; Jiang, Dazong; Yang, Kevin; Yang, Kang

2015-01-01

The cone-beam reconstruction theory has been proposed by Kirillov in 1961, Tuy in 1983, Feldkamp in 1984, Smith in 1985, Pierre Grangeat in 1990. The Fourier slice theorem is proposed by Bracewell 1956, which leads to the Fourier image reconstruction method for parallel-beam geometry. The Fourier slice theorem is extended to fan-beam geometry by Zhao in 1993 and 1995. By combining the above mentioned cone-beam image reconstruction theory and the above mentioned Fourier slice theory of fan-beam geometry, the Fourier slice theorem in cone-beam geometry is proposed by Zhao 1995 in short conference publication. This article offers the details of the derivation and implementation of this Fourier slice theorem for cone-beam geometry. Especially the problem of the reconstruction from Fourier domain has been overcome, which is that the value of in the origin of Fourier space is 0/0. The 0/0 type of limit is proper handled. As examples, the implementation results for the single circle and two perpendicular circle source orbits are shown. In the cone-beam reconstruction if a interpolation process is considered, the number of the calculations for the generalized Fourier slice theorem algorithm is O(N^4), which is close to the filtered back-projection method, here N is the image size of 1-dimension. However the interpolation process can be avoid, in that case the number of the calculations is O(N5).

Improved biochemical preservation of lung slices during cold storage.

Science.gov (United States)

Bull, D A; Connors, R C; Reid, B B; Albanil, A; Stringham, J C; Karwande, S V

2000-05-15

Development of lung preservation solutions typically requires whole-organ models which are animal and labor intensive. These models rely on physiologic rather than biochemical endpoints, making accurate comparison of the relative efficacy of individual solution components difficult. We hypothesized that lung slices could be used to assess preservation of biochemical function during cold storage. Whole rat lungs were precision cut into slices with a thickness of 500 microm and preserved at 4 degrees C in the following solutions: University of Wisconsin (UW), Euro-Collins (EC), low-potassium-dextran (LPD), Kyoto (K), normal saline (NS), or a novel lung preservation solution (NPS) developed using this model. Lung biochemical function was assessed by ATP content (etamol ATP/mg wet wt) and capacity for protein synthesis (cpm/mg protein) immediately following slicing (0 h) and at 6, 12, 18, and 24 h of cold storage. Six slices were assayed at each time point for each solution. The data were analyzed using analysis of variance and are presented as means +/- SD. ATP content was significantly higher in the lung slices stored in NPS compared with all other solutions at each time point (P cold storage. Copyright 2000 Academic Press.

Atypical PKC, PKCλ/ι, activates β-secretase and increases Aβ1-40/42 and phospho-tau in mouse brain and isolated neuronal cells, and may link hyperinsulinemia and other aPKC activators to development of pathological and memory abnormalities in Alzheimer's disease.

Science.gov (United States)

Sajan, Mini P; Hansen, Barbara C; Higgs, Margaret G; Kahn, C Ron; Braun, Ursula; Leitges, Michael; Park, Collin R; Diamond, David M; Farese, Robert V

2018-01-01

Hyperinsulinemia activates brain Akt and PKC-λ/ι and increases Aβ 1-40/42 and phospho-tau in insulin-resistant animals. Here, we examined underlying mechanisms in mice, neuronal cells, and mouse hippocampal slices. Like Aβ 1-40/42 , β-secretase activity was increased in insulin-resistant mice and monkeys. In insulin-resistant mice, inhibition of hepatic PKC-λ/ι sufficient to correct hepatic abnormalities and hyperinsulinemia simultaneously reversed increases in Akt, atypical protein kinase C (aPKC), β-secretase, and Aβ 1-40/42 , and restored acute Akt activation. However, 2 aPKC inhibitors additionally blocked insulin's ability to activate brain PKC-λ/ι and thereby increase β-secretase and Aβ 1-40/42 . Furthermore, direct blockade of brain aPKC simultaneously corrected an impairment in novel object recognition in high-fat-fed insulin-resistant mice. In neuronal cells and/or mouse hippocampal slices, PKC-ι/λ activation by insulin, metformin, or expression of constitutive PKC-ι provoked increases in β-secretase, Aβ 1-40/42 , and phospho-thr-231-tau that were blocked by various PKC-λ/ι inhibitors, but not by an Akt inhibitor. PKC-λ/ι provokes increases in brain β-secretase, Aβ 1-40/42 , and phospho-thr-231-tau. Excessive signaling via PKC-λ/ι may link hyperinsulinemia and other PKC-λ/ι activators to pathological and functional abnormalities in Alzheimer's disease. Published by Elsevier Inc.

Continuous Slice Functional Calculus in Quaternionic Hilbert Spaces

Science.gov (United States)

Ghiloni, Riccardo; Moretti, Valter; Perotti, Alessandro

2013-04-01

The aim of this work is to define a continuous functional calculus in quaternionic Hilbert spaces, starting from basic issues regarding the notion of spherical spectrum of a normal operator. As properties of the spherical spectrum suggest, the class of continuous functions to consider in this setting is the one of slice quaternionic functions. Slice functions generalize the concept of slice regular function, which comprises power series with quaternionic coefficients on one side and that can be seen as an effective generalization to quaternions of holomorphic functions of one complex variable. The notion of slice function allows to introduce suitable classes of real, complex and quaternionic C*-algebras and to define, on each of these C*-algebras, a functional calculus for quaternionic normal operators. In particular, we establish several versions of the spectral map theorem. Some of the results are proved also for unbounded operators. However, the mentioned continuous functional calculi are defined only for bounded normal operators. Some comments on the physical significance of our work are included.

Thermoluminescence results on slices from a Hiroshima tile UHFSFT03

International Nuclear Information System (INIS)

Stoneham, Doreen

1987-01-01

As was reported at the May 1984 Utah thermoluminescence (TL) workshop, high fired tiles and porcelain fragments can be sliced into 200 μm sections with constant surface area. When conventional pre-dose measurements were carried out on these slices the doses evaluated were in good agreement with results obtained by other workers using conventional quartz separation techniques. There are several advantages in using slices. First, less sample is needed as about 50 consecutive slices can be cut from a block measuring typically 1 cm 2 cross section and 2 cm in length. There are no problems with securing grains to the plate or loss of grains during measurement. Hypothetically there is less damage to the grains when they are cut slowly under cold water than when they are crushed. The disadvantage is that other minerals besides quartz are present in the slice and the signal is weaker than that obtained using quartz inclusions

Modeling and Realization of a Bearingless Flux-Switching Slice Motor

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Wolfgang Gruber

2017-03-01

Full Text Available This work introduces a novel bearingless slice motor design: the bearingless flux-switching slice motor. In contrast to state-of-the-art bearingless slice motors, the rotor in this new design does not include any permanent rotor magnets. This offers advantages for disposable devices, such as those used in the medical industry, and extends the range of bearingless slice motors toward high-temperature applications. In this study, our focus is on the analytical modeling of the suspension force torque generation of a single coil and the bearingless motor. We assessed motor performance in relation to motor topology by applying performance factors. A prototype motor was optimized, designed, and manufactured. We also presented the state-of-the-art nonlinear feedback control scheme used. The motor was operated, and both static and dynamic measurements were taken on a test bench, thus successfully demonstrating the functionality and applicability of the novel bearingless slice motor concept.

Assessment of oxidative stress parameters of brain-derived neurotrophic factor heterozygous mice in acute stress model

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Gulay Hacioglu

2016-04-01

Full Text Available Objective(s: Exposing to stress may be associated with increased production of reactive oxygen species (ROS. Therefore, high level of oxidative stress may eventually give rise to accumulation of oxidative damage and development of numerous neurodegenerative diseases. It has been presented that brain-derived neurotrophic factor (BDNF supports neurons against various neurodegenerative conditions. Lately, there has been growing evidence that changes in the cerebral neurotrophic support and especially in the BDNF expression and its engagement with ROS might be important in various disorders and neurodegenerative diseases. Hence, we aimed to investigate protective effects of BDNF against stress-induced oxidative damage. Materials and Methods: Five- to six-month-old male wild-type and BDNF knock-down mice were used in this study. Activities of catalase (CAT and superoxide dismutase (SOD enzymes, and the amount of malondialdehyde (MDA were assessed in the cerebral homogenates of studied groups in response to acute restraint stress. Results: Exposing to acute physiological stress led to significant elevation in the markers of oxidative stress in the cerebral cortexes of experimental groups. Conclusion: As BDNF-deficient mice were observed to be more susceptible to stress-induced oxidative damage, it can be suggested that there is a direct interplay between oxidative stress indicators and BDNF levels in the brain.

ROC [Receiver Operating Characteristics] study of maximum likelihood estimator human brain image reconstructions in PET [Positron Emission Tomography] clinical practice

International Nuclear Information System (INIS)

Llacer, J.; Veklerov, E.; Nolan, D.; Grafton, S.T.; Mazziotta, J.C.; Hawkins, R.A.; Hoh, C.K.; Hoffman, E.J.

1990-10-01

This paper will report on the progress to date in carrying out Receiver Operating Characteristics (ROC) studies comparing Maximum Likelihood Estimator (MLE) and Filtered Backprojection (FBP) reconstructions of normal and abnormal human brain PET data in a clinical setting. A previous statistical study of reconstructions of the Hoffman brain phantom with real data indicated that the pixel-to-pixel standard deviation in feasible MLE images is approximately proportional to the square root of the number of counts in a region, as opposed to a standard deviation which is high and largely independent of the number of counts in FBP. A preliminary ROC study carried out with 10 non-medical observers performing a relatively simple detectability task indicates that, for the majority of observers, lower standard deviation translates itself into a statistically significant detectability advantage in MLE reconstructions. The initial results of ongoing tests with four experienced neurologists/nuclear medicine physicians are presented. Normal cases of 18 F -- fluorodeoxyglucose (FDG) cerebral metabolism studies and abnormal cases in which a variety of lesions have been introduced into normal data sets have been evaluated. We report on the results of reading the reconstructions of 90 data sets, each corresponding to a single brain slice. It has become apparent that the design of the study based on reading single brain slices is too insensitive and we propose a variation based on reading three consecutive slices at a time, rating only the center slice. 9 refs., 2 figs., 1 tab

Identification and two-photon imaging of oligodendrocyte in CA1 region of hippocampal slices

International Nuclear Information System (INIS)

Zhou Wei; Ge Wooping; Zeng Shaoqun; Duan Shumin; Luo Qingming

2007-01-01

Oligodendrocyte (OL) plays a critical role in myelination and axon maintenance in central nervous system. Recent studies show that OL can also express NMDA receptors in development and pathological situations in white matter. There is still lack of studies about OL properties and function in gray matter of brain. Here we reported that some glial cells in CA1 region of rat hippocampal slices (P15-23) had distinct electrophysiological characteristics from the other glia cells in this region, while they displayed uniform properties with OL from white matter in previous report; therefore, they were considered as OL in hippocampus. By loading dye in recording pipette and imaging with two-photon laser scanning microscopy, we acquired the high spatial resolution, three-dimension images of these special cells in live slices. The OL in hippocampus shows a complex process-bearing shape and the distribution of several processes is parallel to Schaffer fiber in CA1 region. When stimulating Schaffer fiber, OL displays a long duration depolarization mediated by inward rectifier potassium channel. This suggested that the OL in CA1 region could sense the neuronal activity and contribute to potassium clearance

Characterization and localization of 3H-arginine8-vasopressin binding to rat kidney and brain tissue

International Nuclear Information System (INIS)

Dorsa, D.M.; Majumdar, L.A.; Petracca, F.M.; Baskin, D.G.; Cornett, L.E.

1983-01-01

Anatomic, behavioral and pharmacologic evidence suggests that arginine8-vasopressin (AVP) serves as a CNS neurotransmitter or neuromodulator. AVP binding to membrane and tissue slice preparations from brain and kidney was characterized, and the anatomical distribution of these binding sites was examined. Conditions for the binding assay were optimized using kidney medullary tissue. Binding of 3 H-AVP (S.A. . 30-51 Ci/mmol, NEN) to brain and kidney membranes and tissue slices was saturable, temperature dependent, linearly related to protein concentration (or number of tissue slices), reversible, and specific since the ability of cold AVP to displace 3 H-AVP from binding was greater than oxytocin and other related peptide fragments. Autoradiographic localization of 3 H-AVP binding was restricted to kidney medullary tissue. In brain tissue, 3 H-AVP binding was found to occur in concentrated foci. Brainstem areas such as the nucleus tractus solitarius (NTS) showed a high density of AVP binding sites. Since local injections of AVP into the NTS have been shown to influence blood pressure, the present study presents the first anatomical evidence for the presence of AVP specific binding sites which might mediate this effect

Design and Development of a tomato Slicing Machine

OpenAIRE

Kamaldeen Oladimeji Salaudeen; Awagu E. F.

2012-01-01

Principle of slicing was reviewed and tomato slicing machine was developed based on appropriate technology. Locally available materials like wood, stainless steel and mild steel were used in the fabrication. The machine was made to cut tomatoes in 2cm thickness. The capacity of the machine is 540.09g per minute and its performance efficiency is 70%.

Sugar uptake and starch biosynthesis by slices of developing maize endosperm

International Nuclear Information System (INIS)

Felker, F.C.; Liu, Kangchien; Shannon, J.C.

1990-01-01

14 C-Sugar uptake and incorporation into starch by slices of developing maize (Zea mays L.) endosperm were examined and compared with sugar uptake by maize endosperm-derived suspension cultures. Rates of sucrose, fructose, and D- and L-glucose uptake by slices were similar, whereas uptake rates for these sugars differed greatly in suspension cultures. Concentration dependence of sucrose, fructose, and D-glucose uptake was biphasic (consisting of linear plus saturable components) with suspension cultures but linear with slices. These and other differences suggest that endosperm slices are freely permeable to sugars. After diffusion into the slices, sugars were metabolized and incorporated into starch. Starch synthesis, but not sugar accumulation, was greatly reduced by 2.5 millimolar p-chloromercuribenzenesulfonic acid and 0.1 millimolar carbonyl cyanide m-chlorophenylhydrazone. Starch synthesis was dependent on kernel age and incubation temperature, but not on external pH (5 through 8). Competing sugars generally did not affect the distribution of 14 C among the soluble sugars extracted from endosperm slices incubated in 14 C-sugars. Competing hexoses reduced the incorporation of 14 C into starch, but competing sucrose did not, suggesting that sucrose is not a necessary intermediate in starch biosynthesis. The bidirectional permeability of endosperm slices to sugars makes the characterization of sugar transport into endosperm slices impossible, however the model system is useful for experiments dealing with starch biosynthesis which occurs in the metabolically active tissue

Pattern of brain computed tomography findings of adult patients with ...

African Journals Online (AJOL)

two adult head injured patients referred to the Radiology department for brain CT over a 3-year period was done. The patients were scanned using Toshiba Aquilion 64 slice spiral CT scan machine, data was collected using a proforma and ...

Sub-acute nickel exposure impairs behavior, alters neuronal microarchitecture, and induces oxidative stress in rats' brain.

Science.gov (United States)

Ijomone, Omamuyovwi Meashack; Okori, Stephen Odey; Ijomone, Olayemi Kafilat; Ebokaiwe, Azubike Peter

2018-02-26

Nickel (Ni) is a heavy metal with wide industrial uses. Environmental and occupational exposures to Ni are potential risk factors for neurological symptoms in humans. The present study investigated the behavior and histomorphological alterations in brain of rats sub-acutely exposed to nickel chloride (NiCl 2 ) and the possible involvement of oxidative stress. Rats were administered with 5, 10 or 20 mg/kg NiCl 2 via intraperitoneal injections for 21 days. Neurobehavioral assessment was performed using the Y-maze and open field test (OFT). Histomorphological analyses of brain tissues, as well as biochemical determination of oxidative stress levels were performed. Results showed that Ni treatments significantly reduced body weight and food intake. Cognitive and motor behaviors on the Y-maze and OFT, respectively, were compromised following Ni treatments. Administration of Ni affected neuronal morphology in the brain and significantly reduced percentage of intact neurons in both hippocampus and striatum. Additionally, markers of oxidative stress levels and nitric oxide (NO) levels were significantly altered following Ni treatments. These data suggest that compromised behavior and brain histomorphology following Ni exposures is associated with increase in oxidative stress.

Early CT signs of progressive hemorrhagic injury following acute traumatic brain injury

Energy Technology Data Exchange (ETDEWEB)

Tong, Wu-song; Zheng, Ping; Xu, Jun-fa; Guo, Yi-jun; Zeng, Jing-song; Yang, Wen-jin; Li, Gao-yi; He, Bin; Yu, Hui [Pudong New Area People' s Hospital, Department of Neurosurgery, Shanghai (China)

2011-05-15

Since progressive hemorrhagic injury (PHI) was introduced in neurosurgical literatures, several studies have been performed, the results of which have influenced doctors but do not define guidelines for the best treatment of PHI. PHI may be confirmed by a serial computerized tomography (CT) scan, and it has been shown to be associated with a fivefold increase in the risk of clinical worsening and is a significant cause of morbidity and mortality as well. So, early detection of PHI is practically important in a clinical situation. To analyze the early CT signs of progressive hemorrhagic injury following acute traumatic brain injury (TBI) and explore their clinical significances, PHI was confirmed by comparing the first and repeated CT scans. Data were analyzed and compared including times from injury to the first CT and signs of the early CT scan. Logistic regression analysis was used to show the risk factors related to PHI. A cohort of 630 TBI patients was evaluated, and there were 189 (30%) patients who suffered from PHI. For patients with their first CT scan obtained as early as 2 h post-injury, there were 116 (77.25%) cases who suffered from PHI. The differences between PHIs and non-PHIs were significant in the initial CT scans showing fracture, subarachnoid hemorrhage (SAH), brain contusion, epidural hematoma (EDH), subdural hematoma (SDH), and multiple hematoma as well as the times from injury to the first CT scan (P < 0.01). Logistic regression analysis showed that early CT scans (EDH, SDH, SAH, fracture, and brain contusion) were predictors of PHI (P < 0.01). For patients with the first CT scan obtained as early as 2 h post-injury, a follow-up CT scan should be performed promptly. If the initial CT scan shows SAH, brain contusion, and primary hematoma with brain swelling, an earlier and dynamic CT scan should be performed for detection of PHI as early as possible and the medical intervention would be enforced in time. (orig.)

Early CT signs of progressive hemorrhagic injury following acute traumatic brain injury

International Nuclear Information System (INIS)

Tong, Wu-song; Zheng, Ping; Xu, Jun-fa; Guo, Yi-jun; Zeng, Jing-song; Yang, Wen-jin; Li, Gao-yi; He, Bin; Yu, Hui

2011-01-01

Since progressive hemorrhagic injury (PHI) was introduced in neurosurgical literatures, several studies have been performed, the results of which have influenced doctors but do not define guidelines for the best treatment of PHI. PHI may be confirmed by a serial computerized tomography (CT) scan, and it has been shown to be associated with a fivefold increase in the risk of clinical worsening and is a significant cause of morbidity and mortality as well. So, early detection of PHI is practically important in a clinical situation. To analyze the early CT signs of progressive hemorrhagic injury following acute traumatic brain injury (TBI) and explore their clinical significances, PHI was confirmed by comparing the first and repeated CT scans. Data were analyzed and compared including times from injury to the first CT and signs of the early CT scan. Logistic regression analysis was used to show the risk factors related to PHI. A cohort of 630 TBI patients was evaluated, and there were 189 (30%) patients who suffered from PHI. For patients with their first CT scan obtained as early as 2 h post-injury, there were 116 (77.25%) cases who suffered from PHI. The differences between PHIs and non-PHIs were significant in the initial CT scans showing fracture, subarachnoid hemorrhage (SAH), brain contusion, epidural hematoma (EDH), subdural hematoma (SDH), and multiple hematoma as well as the times from injury to the first CT scan (P < 0.01). Logistic regression analysis showed that early CT scans (EDH, SDH, SAH, fracture, and brain contusion) were predictors of PHI (P < 0.01). For patients with the first CT scan obtained as early as 2 h post-injury, a follow-up CT scan should be performed promptly. If the initial CT scan shows SAH, brain contusion, and primary hematoma with brain swelling, an earlier and dynamic CT scan should be performed for detection of PHI as early as possible and the medical intervention would be enforced in time. (orig.)

Quantitative parameters to compare image quality of non-invasive coronary angiography with 16-slice, 64-slice and dual-source computed tomography

International Nuclear Information System (INIS)

Burgstahler, Christof; Reimann, Anja; Brodoefel, Harald; Tsiflikas, Ilias; Thomas, Christoph; Heuschmid, Martin; Daferner, Ulrike; Drosch, Tanja; Schroeder, Stephen; Herberts, Tina

2009-01-01

Multi-slice computed tomography (MSCT) is a non-invasive modality to visualize coronary arteries with an overall good image quality. Improved spatial and temporal resolution of 64-slice and dual-source computed tomography (DSCT) scanners are supposed to have a positive impact on diagnostic accuracy and image quality. However, quantitative parameters to compare image quality of 16-slice, 64-slice MSCT and DSCT are missing. A total of 256 CT examinations were evaluated (Siemens, Sensation 16: n=90; Siemens Sensation 64: n=91; Siemens Definition: n=75). Mean Hounsfield units (HU) were measured in the cavum of the left ventricle (LV), the ascending aorta (Ao), the left ventricular myocardium (My) and the proximal part of the left main (LM), the left anterior descending artery (LAD), the right coronary artery (RCA) and the circumflex artery (CX). Moreover, the ratio of intraluminal attenuation (HU) to myocardial attenuation was assessed for all coronary arteries. Clinical data [body mass index (BMI), gender, heart rate] were accessible for all patients. Mean attenuation (CA) of the coronary arteries was significantly higher for DSCT in comparison to 64- and 16-slice MSCT within the RCA [347±13 vs. 254±14 (64-MSCT) vs. 233±11 (16-MSCT) HU], LM (362±11/275 ± 12/262±9), LAD (332±17/248±19/219±14) and LCX (310±12/210±13/221±10, all p<0.05), whereas there was no significant difference between DSCT and 64-MSCT for the LV, the Ao and My. Heart rate had a significant impact on CA ratio in 16-slice and 64-slice CT only (p<0.05). BMI had no impact on the CA ratio in DSCT only (p<0.001). Improved spatial and temporal resolution of dual-source CT is associated with better opacification of the coronary arteries and a better contrast with the myocardium, which is independent of heart rate. In comparison to MSCT, opacification of the coronary arteries at DSCT is not affected by BMI. The main advantage of DSCT lies with the heart rate independency, which might have a

Pathophysiological aspects of acute hepatic encephalopathy in the rat

International Nuclear Information System (INIS)

Deutz, N.E.P.

1988-01-01

The aim of the present thesis is to elucidate the pathogenesis of acute hepatic encephalopathy (HE). In order to study acute HE, plasma and brain concentrations were measured of ammonia, aminoacids, lactate and polyamines as well as brain energy rich phosphates. In addition new techniques of brain research were developed and applied. 277 refs.; 29 figs.; 18 tabs

Improved biochemical preservation of heart slices during cold storage.

Science.gov (United States)

Bull, D A; Reid, B B; Connors, R C; Albanil, A; Stringham, J C; Karwande, S V

2000-01-01

Development of myocardial preservation solutions requires the use of whole organ models which are animal and labor intensive. These models rely on physiologic rather than biochemical endpoints, making accurate comparison of the relative efficacy of individual solution components difficult. We hypothesized that myocardial slices could be used to assess preservation of biochemical function during cold storage. Whole rat hearts were precision cut into slices with a thickness of 200 microm and preserved at 4 degrees C in one of the following solutions: Columbia University (CU), University of Wisconsin (UW), D5 0.2% normal saline with 20 meq/l KCL (QNS), normal saline (NS), or a novel cardiac preservation solution (NPS) developed using this model. Myocardial biochemical function was assessed by ATP content (etamoles ATP/mg wet weight) and capacity for protein synthesis (counts per minute (cpm)/mg protein) immediately following slicing (0 hours), and at 6, 12, 18, and 24 hours of cold storage. Six slices were assayed at each time point for each solution. The data were analyzed using analysis of variance and are presented as the mean +/- standard deviation. ATP content was higher in the heart slices stored in the NPS compared to all other solutions at 6, 12, 18 and 24 hours of cold storage (p cold storage (p cold storage.

The impact of dietary isoflavonoids on malignant brain tumors

International Nuclear Information System (INIS)

Sehm, Tina; Fan, Zheng; Weiss, Ruth; Schwarz, Marc; Engelhorn, Tobias; Hore, Nirjhar; Doerfler, Arnd; Buchfelder, Michael; Eyüpoglu, IIker Y; Savaskan, Nic E

2014-01-01

Poor prognosis and limited therapeutic options render malignant brain tumors one of the most devastating diseases in clinical medicine. Current treatment strategies attempt to expand the therapeutic repertoire through the use of multimodal treatment regimens. It is here that dietary fibers have been recently recognized as a supportive natural therapy in augmenting the body's response to tumor growth. Here, we investigated the impact of isoflavonoids on primary brain tumor cells. First, we treated glioma cell lines and primary astrocytes with various isoflavonoids and phytoestrogens. Cell viability in a dose-dependent manner was measured for biochanin A (BCA), genistein (GST), and secoisolariciresinol diglucoside (SDG). Dose–response action for the different isoflavonoids showed that BCA is highly effective on glioma cells and nontoxic for normal differentiated brain tissues. We further investigated BCA in ex vivo and in vivo experimentations. Organotypic brain slice cultures were performed and treated with BCA. For in vivo experiments, BCA was intraperitoneal injected in tumor-implanted Fisher rats. Tumor size and edema were measured and quantified by magnetic resonance imaging (MRI) scans. In vascular organotypic glioma brain slice cultures (VOGIM) we found that BCA operates antiangiogenic and neuroprotective. In vivo MRI scans demonstrated that administered BCA as a monotherapy was effective in reducing significantly tumor-induced brain edema and showed a trend for prolonged survival. Our results revealed that dietary isoflavonoids, in particular BCA, execute toxicity toward glioma cells, antiangiogenic, and coevally neuroprotective properties, and therefore augment the range of state-of-the-art multimodal treatment approach

Salicylate-Induced Suppression of Electrically Driven Activity in Brain Slices from the Auditory Cortex of Aging Mice

Directory of Open Access Journals (Sweden)

Minoru Namikawa

2017-12-01

Full Text Available The prevalence of tinnitus is known to increase with age. The age-dependent mechanisms of tinnitus may have important implications for the development of new therapeutic treatments. High doses of salicylate can be used experimentally to induce transient tinnitus and hearing loss. Although accumulating evidence indicates that salicylate induces tinnitus by directly targeting neurons in the peripheral and central auditory systems, the precise effect of salicylate on neural networks in the auditory cortex (AC is unknown. Here, we examined salicylate-induced changes in stimulus-driven laminar responses of AC slices with salicylate superfusion in young and aged senescence-accelerated-prone (SAMP and -resistant (SAMR mice. Of the two strains, SAMP1 is known to be a more suitable model of presbycusis. We recorded stimulus-driven laminar local field potential (LFP responses at multi sites in AC slice preparations. We found that for all AC slices in the two strains, salicylate always reduced stimulus-driven LFP responses in all layers. However, for the amplitudes of the LFP responses, the two senescence-accelerated mice (SAM strains showed different laminar properties between the pre- and post-salicylate conditions, reflecting strain-related differences in local circuits. As for the relationships between auditory brainstem response (ABR thresholds and the LFP amplitude ratios in the pre- vs. post-salicylate condition, we found negative correlations in layers 2/3 and 4 for both older strains, and in layer 5 (L5 in older SAMR1. In contrast, the GABAergic agonist muscimol (MSC led to positive correlations between ABR thresholds and LFP amplitude ratios in the pre- vs. post-MSC condition in younger SAM mice from both strains. Further, in younger mice, salicylate decreased the firing rate in AC L4 pyramidal neurons. Thus, salicylate can directly reduce neural excitability of L4 pyramidal neurons and thereby influence AC neural circuit activity. That we

Normalized wall index specific and MRI-based stress analysis of atherosclerotic carotid plaques. A study comparing acutely symptomatic and asymptomatic patients

International Nuclear Information System (INIS)

Zhu, C.; Teng, Z.; Sadat, U.; Young, V.E.; Graves, M.J.; Gillard, J.H.; Li Zhiyong

2010-01-01

Biomechanical stresses play an important role in determining plaque stability. Quantification of these simulated stresses can be potentially used to assess plaque vulnerability and differentiate different patient groups. 54 asymptomatic and 45 acutely symptomatic patients underwent in vivo multicontrast magnetic resonance imaging (MRI) of the carotid arteries. Plaque geometry used for finite element analysis was derived from in vivo MRI at the sites of maximum and minimum plaque burden. In total, 198 slices were used for the computational simulations. A pre-shrink technique was used to refine the simulation. Maximum principle stress at the vulnerable plaque sites (id est (ie), critical stress) was extracted for the selected slices and a comparison was performed between the 2 groups. Critical stress in the slice with maximum plaque burden is significantly higher in acutely symptomatic patients as compared to asymptomatic patients (median, inter quartile range: 198.0 kPa (119.8-359.0 kPa) vs 138.4 kPa (83.8-242.6 kPa), P=0.04). No significant difference was found in the slice with minimum plaque burden between the 2 groups (196.7 kPa (133.3-282.7 kPa) vs 182.4 kPa (117.2-310.6 kPa), P=0.82). Acutely symptomatic carotid plaques have significantly high biomechanical stresses than asymptomatic plaques. This might be potentially useful for establishing a biomechanical risk stratification criteria based on plaque burden in future studies. (author)