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Sample records for brain slice invasion

  1. Geometry Processing of Conventionally Produced Mouse Brain Slice Images.

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    Agarwal, Nitin; Xu, Xiangmin; Gopi, M

    2018-04-21

    Brain mapping research in most neuroanatomical laboratories relies on conventional processing techniques, which often introduce histological artifacts such as tissue tears and tissue loss. In this paper we present techniques and algorithms for automatic registration and 3D reconstruction of conventionally produced mouse brain slices in a standardized atlas space. This is achieved first by constructing a virtual 3D mouse brain model from annotated slices of Allen Reference Atlas (ARA). Virtual re-slicing of the reconstructed model generates ARA-based slice images corresponding to the microscopic images of histological brain sections. These image pairs are aligned using a geometric approach through contour images. Histological artifacts in the microscopic images are detected and removed using Constrained Delaunay Triangulation before performing global alignment. Finally, non-linear registration is performed by solving Laplace's equation with Dirichlet boundary conditions. Our methods provide significant improvements over previously reported registration techniques for the tested slices in 3D space, especially on slices with significant histological artifacts. Further, as one of the application we count the number of neurons in various anatomical regions using a dataset of 51 microscopic slices from a single mouse brain. To the best of our knowledge the presented work is the first that automatically registers both clean as well as highly damaged high-resolutions histological slices of mouse brain to a 3D annotated reference atlas space. This work represents a significant contribution to this subfield of neuroscience as it provides tools to neuroanatomist for analyzing and processing histological data. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Establishment and Characterization of a Tumor Stem Cell-Based Glioblastoma Invasion Model.

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    Stine Skov Jensen

    Full Text Available Glioblastoma is the most frequent and malignant brain tumor. Recurrence is inevitable and most likely connected to tumor invasion and presence of therapy resistant stem-like tumor cells. The aim was therefore to establish and characterize a three-dimensional in vivo-like in vitro model taking invasion and tumor stemness into account.Glioblastoma stem cell-like containing spheroid (GSS cultures derived from three different patients were established and characterized. The spheroids were implanted in vitro into rat brain slice cultures grown in stem cell medium and in vivo into brains of immuno-compromised mice. Invasion was followed in the slice cultures by confocal time-lapse microscopy. Using immunohistochemistry, we compared tumor cell invasion as well as expression of proliferation and stem cell markers between the models.We observed a pronounced invasion into brain slice cultures both by confocal time-lapse microscopy and immunohistochemistry. This invasion closely resembled the invasion in vivo. The Ki-67 proliferation indexes in spheroids implanted into brain slices were lower than in free-floating spheroids. The expression of stem cell markers varied between free-floating spheroids, spheroids implanted into brain slices and tumors in vivo.The established invasion model kept in stem cell medium closely mimics tumor cell invasion into the brain in vivo preserving also to some extent the expression of stem cell markers. The model is feasible and robust and we suggest the model as an in vivo-like model with a great potential in glioma studies and drug discovery.

  3. Brain slice on a chip: opportunities and challenges of applying microfluidic technology to intact tissues.

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    Huang, Yu; Williams, Justin C; Johnson, Stephen M

    2012-06-21

    Isolated brain tissue, especially brain slices, are valuable experimental tools for studying neuronal function at the network, cellular, synaptic, and single channel levels. Neuroscientists have refined the methods for preserving brain slice viability and function and converged on principles that strongly resemble the approach taken by engineers in developing microfluidic devices. With respect to brain slices, microfluidic technology may 1) overcome the traditional limitations of conventional interface and submerged slice chambers and improve oxygen/nutrient penetration into slices, 2) provide better spatiotemporal control over solution flow/drug delivery to specific slice regions, and 3) permit successful integration with modern optical and electrophysiological techniques. In this review, we highlight the unique advantages of microfluidic devices for in vitro brain slice research, describe recent advances in the integration of microfluidic devices with optical and electrophysiological instrumentation, and discuss clinical applications of microfluidic technology as applied to brain slices and other non-neuronal tissues. We hope that this review will serve as an interdisciplinary guide for both neuroscientists studying brain tissue in vitro and engineers as they further develop microfluidic chamber technology for neuroscience research.

  4. Establishment and Characterization of a Tumor Stem Cell-Based Glioblastoma Invasion Model

    DEFF Research Database (Denmark)

    Jensen, Stine Skov; Meyer, Morten; Petterson, Stine Asferg

    2016-01-01

    AIMS: Glioblastoma is the most frequent and malignant brain tumor. Recurrence is inevitable and most likely connected to tumor invasion and presence of therapy resistant stem-like tumor cells. The aim was therefore to establish and characterize a three-dimensional in vivo-like in vitro model taking...... invasion and tumor stemness into account. METHODS: Glioblastoma stem cell-like containing spheroid (GSS) cultures derived from three different patients were established and characterized. The spheroids were implanted in vitro into rat brain slice cultures grown in stem cell medium and in vivo into brains...... of immuno-compromised mice. Invasion was followed in the slice cultures by confocal time-lapse microscopy. Using immunohistochemistry, we compared tumor cell invasion as well as expression of proliferation and stem cell markers between the models. RESULTS: We observed a pronounced invasion into brain slice...

  5. Novel culturing platform for brain slices and neuronal cells

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith; Al Atraktchi, Fatima Al-Zahraa; Bakmand, Tanya

    2015-01-01

    In this paper we demonstrate a novel culturing system for brain slices and neuronal cells, which can control the concentration of nutrients and the waste removal from the culture by adjusting the fluid flow within the device. The entire system can be placed in an incubator. The system has been...... tested successfully with brain slices and PC12 cells. The culture substrate can be modified using metal electrodes and/or nanostructures for conducting electrical measurements while culturing and for better mimicking the in vivo conditions....

  6. Fluidic system for long-term in vitro culturing and monitoring of organotypic brain slices

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    Bakmand, Tanya; Troels-Smith, Ane R.; Dimaki, Maria

    2015-01-01

    Brain slice preparations cultured in vitro have long been used as a simplified model for studying brain development, electrophysiology, neurodegeneration and neuroprotection. In this paper an open fluidic system developed for improved long term culturing of organotypic brain slices is presented....... The positive effect of continuous flow of growth medium, and thus stability of the glucose concentration and waste removal, is simulated and compared to the effect of stagnant medium that is most often used in tissue culturing. Furthermore, placement of the tissue slices in the developed device was studied...... by numerical simulations in order to optimize the nutrient distribution. The device was tested by culturing transverse hippocampal slices from 7 days old NMRI mice for a duration of 14 days. The slices were inspected visually and the slices cultured in the fluidic system appeared to have preserved...

  7. Long-term brain slice culturing in a microfluidic platform

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    Vedarethinam, Indumathi; Avaliani, N.; Tønnesen, J.

    2011-01-01

    In this work, we present the development of a transparent poly(methyl methacrylate) (PMMA) based microfluidic culture system for handling long-term brain slice cultures independent of an incubator. The different stages of system development have been validated by culturing GFP producing brain sli...

  8. Neuropeptide processing in regional brain slices: Effect of conformation and sequence

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    Li, Z.W.; Bijl, W.A.; van Nispen, J.W.; Brendel, K.; Davis, T.P. (Univ. of Arizona, Tucson (USA))

    1990-05-01

    The central enzymatic stability of des-enkephalin-gamma-endorphin and its synthetic analogs (cycloN alpha 6, C delta 11)beta-endorphin-(6-17) and (Pro7, Lys(Ac)9)-beta-endorphin(6-17) was studied in vitro using a newly developed, regionally dissected rat brain slice, time course incubation procedure. Tissue slice viability was estimated as the ability of the brain slice to take up or release gamma-(3H)aminobutyric acid after high K+ stimulation. Results demonstrated stability of uptake/release up to 5 hr of incubation, suggesting tissue viability over this period. The estimated half-life of peptides based on the results obtained in our incubation protocol suggest that the peptides studied are metabolized at different rates in the individual brain regions tested. A good correlation exists between the high enzyme activity of neutral endopeptidase and the rapid degradation of des-enkephalin-gamma-endorphin and (cycloN alpha 6, C delata 11)beta-endorphin-(6-17) in caudate putamen. Proline substitution combined with lysine acetylation appears to improve resistance to enzymatic metabolism in caudate putamen and hypothalamus. However, cyclization of des-enkephalin-gamma-endorphin forming an amide bond between the alpha-NH2 of the N-terminal threonine and the gamma-COOH of glutamic acid did not improve peptide stability in any brain region tested. The present study has shown that the brain slice technique is a valid and unique approach to study neuropeptide metabolism in small, discrete regions of rat brain where peptides, peptidases and receptors are colocalized and that specific structural modifications can improve peptide stability.

  9. Organotypic hippocampal slice cultures for studies of brain damage, neuroprotection and neurorepair

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    Noraberg, Jens; Poulsen, Frantz Rom; Blaabjerg, Morten

    2005-01-01

    Slices of developing brain tissue can be grown for several weeks as so-called organotypic slice cultures. Here we summarize and review studies using hippocampal slice cultures to investigate mechanisms and treatment strategies for the neurodegenerative disorders like stroke (cerebral ischemia......), Alzheimer's disease (AD) and epilepsia. Studies of non-excitotoxic neurotoxic compounds and the experimental use of slice cultures in studies of HIV neurotoxicity, traumatic brain injury (TBI) and neurogenesis are included. For cerebral ischemia, experimental models with oxygen-glucose deprivation (OGD......) and exposure to glutamate receptor agonists (excitotoxins) are reviewed. For epilepsia, focus is on induction of seizures with effects on neuronal loss, axonal sprouting and neurogenesis. For Alzheimer's disease, the review centers on the use of beta-amyloid (Abeta) in different models, while the section...

  10. Diagnostic accuracy of non-invasive 64-slice CT coronary angiography in patients with stable angina pectoris

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    Pugliese, Francesca; Krestin, Gabriel P. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Mollet, Nico R.A.; deFeyter, Pim J. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands); Runza, Giuseppe [University of Palermo, Department of Radiology, Palermo (Italy); Azienda Ospedaliera di Parma, Department of Radiology, Parma (Italy); Mieghem, Carlos van; Meijboom, Willem B.; Baks, Timo [Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands); Malagutti, Patrizia [Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands); University of Ferrara, Department of Cardiology, Ferrara (Italy); Cademartiri, Filippo [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Azienda Ospedaliera di Parma, Department of Radiology, Parma (Italy)

    2006-03-15

    Multislice computed tomography (CT) is an emerging technique for the non-invasive detection of coronary stenoses. While the diagnostic accuracy of 4-slice scanners was limited, 16-slice CT imagers showed promising results due to increased temporal and spatial resolution. These technical advances prompted us to evaluate the diagnostic performance of 64-slice CT coronary angiography in the detection of significant stenoses (defined as {>=} 50% luminal diameter reduction) versus invasive quantitative coronary angiography (QCA). Thirty-five patients with stable angina pectoris underwent CT coronary angiography performed with a 64-slice scanner (gantry rotation time 330 ms, individual detector width 0.6 mm) prior to conventional coronary angiography. Patients with heart rates >70 beats/min received 100 mg metoprolol orally. One hundred millilitres of contrast agent with an iodine concentration of 400 mgl/ml were injected at a rate of 5 ml/s into the antecubital vein. The CT scan was triggered with the bolus tracking technique. The sensitivity, specificity and the positive and negative predictive values of 64-slice CT were 99%, 96%, 78% and 99%, respectively, on a per-segment basis. The values obtained on a per-patient basis were 100%, 90%, 96% and 100%, respectively. When referral to catheterisation is questionable, CT coronary angiography may identify subjects with normal angiograms and consistently decrease the number of unnecessary invasive procedures. (orig.)

  11. Diagnostic accuracy of non-invasive 64-slice CT coronary angiography in patients with stable angina pectoris

    International Nuclear Information System (INIS)

    Pugliese, Francesca; Krestin, Gabriel P.; Mollet, Nico R.A.; DeFeyter, Pim J.; Runza, Giuseppe; Mieghem, Carlos van; Meijboom, Willem B.; Baks, Timo; Malagutti, Patrizia; Cademartiri, Filippo

    2006-01-01

    Multislice computed tomography (CT) is an emerging technique for the non-invasive detection of coronary stenoses. While the diagnostic accuracy of 4-slice scanners was limited, 16-slice CT imagers showed promising results due to increased temporal and spatial resolution. These technical advances prompted us to evaluate the diagnostic performance of 64-slice CT coronary angiography in the detection of significant stenoses (defined as ≥ 50% luminal diameter reduction) versus invasive quantitative coronary angiography (QCA). Thirty-five patients with stable angina pectoris underwent CT coronary angiography performed with a 64-slice scanner (gantry rotation time 330 ms, individual detector width 0.6 mm) prior to conventional coronary angiography. Patients with heart rates >70 beats/min received 100 mg metoprolol orally. One hundred millilitres of contrast agent with an iodine concentration of 400 mgl/ml were injected at a rate of 5 ml/s into the antecubital vein. The CT scan was triggered with the bolus tracking technique. The sensitivity, specificity and the positive and negative predictive values of 64-slice CT were 99%, 96%, 78% and 99%, respectively, on a per-segment basis. The values obtained on a per-patient basis were 100%, 90%, 96% and 100%, respectively. When referral to catheterisation is questionable, CT coronary angiography may identify subjects with normal angiograms and consistently decrease the number of unnecessary invasive procedures. (orig.)

  12. Rat brain sagittal organotypic slice cultures as an ex vivo dopamine cell loss system.

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    McCaughey-Chapman, Amy; Connor, Bronwen

    2017-02-01

    Organotypic brain slice cultures are a useful tool to study neurological function as they provide a more complex, 3-dimensional system than standard 2-dimensional in vitro cell cultures. Building on a previously developed mouse brain slice culture protocol, we have developed a rat sagittal brain slice culture system as an ex vivo model of dopamine cell loss. We show that rat brain organotypic slice cultures remain viable for up to 6 weeks in culture. Using Fluoro-Gold axonal tracing, we demonstrate that the slice 3-dimensional cytoarchitecture is maintained over a 4 week culturing period, with particular focus on the nigrostriatal pathway. Treatment of the cultures with 6-hydroxydopamine and desipramine induces a progressive loss of Fluoro-Gold-positive nigral cells with a sustained loss of tyrosine hydroxylase-positive nigral cells. This recapitulates the pattern of dopaminergic degeneration observed in the rat partial 6-hydroxydopamine lesion model and, most importantly, the progressive pathology of Parkinson's disease. Our slice culture platform provides an advance over other systems, as we demonstrate for the first time 3-dimensional cytoarchitecture maintenance of rat nigrostriatal sagittal slices for up to 6 weeks. Our ex vivo organotypic slice culture system provides a long term cellular platform to model Parkinson's disease, allowing for the elucidation of mechanisms involved in dopaminergic neuron degeneration and the capability to study cellular integration and plasticity ex vivo. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Organotypic brain slice cultures of adult transgenic P301S mice--a model for tauopathy studies.

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    Agneta Mewes

    Full Text Available BACKGROUND: Organotypic brain slice cultures represent an excellent compromise between single cell cultures and complete animal studies, in this way replacing and reducing the number of animal experiments. Organotypic brain slices are widely applied to model neuronal development and regeneration as well as neuronal pathology concerning stroke, epilepsy and Alzheimer's disease (AD. AD is characterized by two protein alterations, namely tau hyperphosphorylation and excessive amyloid β deposition, both causing microglia and astrocyte activation. Deposits of hyperphosphorylated tau, called neurofibrillary tangles (NFTs, surrounded by activated glia are modeled in transgenic mice, e.g. the tauopathy model P301S. METHODOLOGY/PRINCIPAL FINDINGS: In this study we explore the benefits and limitations of organotypic brain slice cultures made of mature adult transgenic mice as a potential model system for the multifactorial phenotype of AD. First, neonatal (P1 and adult organotypic brain slice cultures from 7- to 10-month-old transgenic P301S mice have been compared with regard to vitality, which was monitored with the lactate dehydrogenase (LDH- and the MTT (3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assays over 15 days. Neonatal slices displayed a constant high vitality level, while the vitality of adult slice cultures decreased significantly upon cultivation. Various preparation and cultivation conditions were tested to augment the vitality of adult slices and improvements were achieved with a reduced slice thickness, a mild hypothermic cultivation temperature and a cultivation CO(2 concentration of 5%. Furthermore, we present a substantial immunohistochemical characterization analyzing the morphology of neurons, astrocytes and microglia in comparison to neonatal tissue. CONCLUSION/SIGNIFICANCE: Until now only adolescent animals with a maximum age of two months have been used to prepare organotypic brain slices. The current study

  14. Modelling glioblastoma tumour-host cell interactions using adult brain organotypic slice co-culture

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    Maria Angeles Marques-Torrejon

    2018-02-01

    Full Text Available Glioblastoma multiforme (GBM is an aggressive incurable brain cancer. The cells that fuel the growth of tumours resemble neural stem cells found in the developing and adult mammalian forebrain. These are referred to as glioma stem cells (GSCs. Similar to neural stem cells, GSCs exhibit a variety of phenotypic states: dormant, quiescent, proliferative and differentiating. How environmental cues within the brain influence these distinct states is not well understood. Laboratory models of GBM can be generated using either genetically engineered mouse models, or via intracranial transplantation of cultured tumour initiating cells (mouse or human. Unfortunately, these approaches are expensive, time-consuming, low-throughput and ill-suited for monitoring live cell behaviours. Here, we explored whole adult brain coronal organotypic slices as an alternative model. Mouse adult brain slices remain viable in a serum-free basal medium for several weeks. GSCs can be easily microinjected into specific anatomical sites ex vivo, and we demonstrate distinct responses of engrafted GSCs to diverse microenvironments in the brain tissue. Within the subependymal zone – one of the adult neural stem cell niches – injected tumour cells could effectively engraft and respond to endothelial niche signals. Tumour-transplanted slices were treated with the antimitotic drug temozolomide as proof of principle of the utility in modelling responses to existing treatments. Engraftment of mouse or human GSCs onto whole brain coronal organotypic brain slices therefore provides a simplified, yet flexible, experimental model. This will help to increase the precision and throughput of modelling GSC-host brain interactions and complements ongoing in vivo studies. This article has an associated First Person interview with the first author of the paper.

  15. Automated fetal brain segmentation from 2D MRI slices for motion correction.

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    Keraudren, K; Kuklisova-Murgasova, M; Kyriakopoulou, V; Malamateniou, C; Rutherford, M A; Kainz, B; Hajnal, J V; Rueckert, D

    2014-11-01

    Motion correction is a key element for imaging the fetal brain in-utero using Magnetic Resonance Imaging (MRI). Maternal breathing can introduce motion, but a larger effect is frequently due to fetal movement within the womb. Consequently, imaging is frequently performed slice-by-slice using single shot techniques, which are then combined into volumetric images using slice-to-volume reconstruction methods (SVR). For successful SVR, a key preprocessing step is to isolate fetal brain tissues from maternal anatomy before correcting for the motion of the fetal head. This has hitherto been a manual or semi-automatic procedure. We propose an automatic method to localize and segment the brain of the fetus when the image data is acquired as stacks of 2D slices with anatomy misaligned due to fetal motion. We combine this segmentation process with a robust motion correction method, enabling the segmentation to be refined as the reconstruction proceeds. The fetal brain localization process uses Maximally Stable Extremal Regions (MSER), which are classified using a Bag-of-Words model with Scale-Invariant Feature Transform (SIFT) features. The segmentation process is a patch-based propagation of the MSER regions selected during detection, combined with a Conditional Random Field (CRF). The gestational age (GA) is used to incorporate prior knowledge about the size and volume of the fetal brain into the detection and segmentation process. The method was tested in a ten-fold cross-validation experiment on 66 datasets of healthy fetuses whose GA ranged from 22 to 39 weeks. In 85% of the tested cases, our proposed method produced a motion corrected volume of a relevant quality for clinical diagnosis, thus removing the need for manually delineating the contours of the brain before motion correction. Our method automatically generated as a side-product a segmentation of the reconstructed fetal brain with a mean Dice score of 93%, which can be used for further processing. Copyright

  16. Analysis of lipid raft molecules in the living brain slices.

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    Kotani, Norihiro; Nakano, Takanari; Ida, Yui; Ito, Rina; Hashizume, Miki; Yamaguchi, Arisa; Seo, Makoto; Araki, Tomoyuki; Hojo, Yasushi; Honke, Koichi; Murakoshi, Takayuki

    2017-08-24

    Neuronal plasma membrane has been thought to retain a lot of lipid raft components which play important roles in the neural function. Although the biochemical analyses of lipid raft using brain tissues have been extensively carried out in the past 20 years, many of their experimental conditions do not coincide with those of standard neuroscience researches such as neurophysiology and neuropharmacology. Hence, the physiological methods for lipid raft analysis that can be compatible with general neuroscience have been required. Herein, we developed a system to physiologically analyze ganglioside GM1-enriched lipid rafts in brain tissues using the "Enzyme-Mediated Activation of Radical Sources (EMARS)" method that we reported (Kotani N. et al. Proc. Natl. Acad. Sci. U S A 105, 7405-7409 (2008)). The EMARS method was applied to acute brain slices prepared from mouse brains in aCSF solution using the EMARS probe, HRP-conjugated cholera toxin subunit B, which recognizes ganglioside GM1. The membrane molecules present in the GM1-enriched lipid rafts were then labeled with fluorescein under the physiological condition. The fluorescein-tagged lipid raft molecules called "EMARS products" distributed differentially among various parts of the brain. On the other hand, appreciable differences were not detected among segments along the longitudinal axis of the hippocampus. We further developed a device to label the lipid raft molecules in acute hippocampal slices under two different physiological conditions to detect dynamics of the lipid raft molecules during neural excitation. Using this device, several cell membrane molecules including Thy1, known as a lipid raft resident molecule in neurons, were confirmed by the EMARS method in living hippocampal slices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. 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

  18. 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 ...

  19. 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.

  20. 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...

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. The energy demand of fast neuronal network oscillations: insights from brain slice preparations

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    Oliver eKann

    2012-01-01

    Full Text Available Fast neuronal network oscillations in the gamma range (30-100 Hz in the cerebral cortex have been implicated in higher cognitive functions such as sensual perception, working memory, and, perhaps, consciousness. However, little is known about the energy demand of gamma oscillations. This is mainly caused by technical limitations that are associated with simultaneous recordings of neuronal activity and energy metabolism in small neuronal networks and at the level of mitochondria in vivo. Thus recent studies have focused on brain slice preparations to address the energy demand of gamma oscillations in vitro. Here, reports will be summarized and discussed that combined electrophysiological recordings, oxygen sensor microelectrodes and live-cell fluorescence imaging in acutely prepared slices and organotypic slice cultures of the hippocampus from both, mouse and rat. These reports consistently show that gamma oscillations can be reliably induced in hippocampal slice preparations by different pharmacological tools. They suggest that gamma oscillations are associated with high energy demand, requiring both rapid adaptation of oxidative energy metabolism and sufficient supply with oxygen and nutrients. These findings might help to explain the exceptional vulnerability of higher cognitive functions during pathological processes of the brain, such as circulatory disturbances, genetic mitochondrial diseases, and neurodegeneration.

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

    Science.gov (United States)

    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

  7. 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.

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

    Science.gov (United States)

    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

  9. A brain slice bath for physiology and compound microscopy, with dual-sided perifusion.

    Science.gov (United States)

    Heyward, P M

    2010-12-01

    Contemporary in vitro brain slice studies can employ compound microscopes to identify individual neurons or their processes for physiological recording or imaging. This requires that the bath used to maintain the tissue fits within the working distances of a water-dipping objective and microscope condenser. A common means of achieving this is to maintain thin tissue slices on the glass floor of a recording bath, exposing only one surface of the tissue to oxygenated bathing medium. Emerging evidence suggests that physiology can be compromised by this approach. Flowing medium past both sides of submerged brain slices is optimal, but recording baths utilizing this principle are not readily available for use on compound microscopes. This paper describes a tissue bath designed specifically for microscopy and physiological recording, in which temperature-controlled medium flows past both sides of the slices. A particular feature of this design is the use of concentric mesh rings to support and transport the live tissue without mechanical disturbance. The design is also easily adapted for use with thin acute slices, cultured slices, and acutely dispersed or cultured cells maintained either on cover slips or placed directly on the floor of the bath. The low profile of the bath provides a low angle of approach for electrodes, and allows use of standard condensers, nosepieces and water-dipping objective lenses. If visualization of individual neurons is not required, the bath can be mounted on a simple stand and used with a dissecting microscope. Heating is integral to the bath, and any temperature controller capable of driving a resistive load can be used. The bath is robust, readily constructed and requires minimal maintenance. Full construction and operation details are given. © 2010 The Author Journal of Microscopy © 2010 The Royal Microscopical Society.

  10. 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...

  11. Intersection Based Motion Correction of Multi-Slice MRI for 3D 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

    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

  12. 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

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

    Science.gov (United States)

    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.

  14. 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....

  15. Targeting neurotransmitter receptors with nanoparticles in vivo allows single-molecule tracking in acute brain slices

    Science.gov (United States)

    Varela, Juan A.; Dupuis, Julien P.; Etchepare, Laetitia; Espana, Agnès; Cognet, Laurent; Groc, Laurent

    2016-03-01

    Single-molecule imaging has changed the way we understand many biological mechanisms, particularly in neurobiology, by shedding light on intricate molecular events down to the nanoscale. However, current single-molecule studies in neuroscience have been limited to cultured neurons or organotypic slices, leaving as an open question the existence of fast receptor diffusion in intact brain tissue. Here, for the first time, we targeted dopamine receptors in vivo with functionalized quantum dots and were able to perform single-molecule tracking in acute rat brain slices. We propose a novel delocalized and non-inflammatory way of delivering nanoparticles (NPs) in vivo to the brain, which allowed us to label and track genetically engineered surface dopamine receptors in neocortical neurons, revealing inherent behaviour and receptor activity regulations. We thus propose a NP-based platform for single-molecule studies in the living brain, opening new avenues of research in physiological and pathological animal models.

  16. 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)

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

    Science.gov (United States)

    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.

  18. 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....

  19. 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

  20. 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.

  1. 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

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

    Science.gov (United States)

    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.

  3. Non-invasive brain-to-brain interface (BBI: establishing functional links between two brains.

    Directory of Open Access Journals (Sweden)

    Seung-Schik Yoo

    Full Text Available Transcranial focused ultrasound (FUS is capable of modulating the neural activity of specific brain regions, with a potential role as a non-invasive computer-to-brain interface (CBI. In conjunction with the use of brain-to-computer interface (BCI techniques that translate brain function to generate computer commands, we investigated the feasibility of using the FUS-based CBI to non-invasively establish a functional link between the brains of different species (i.e. human and Sprague-Dawley rat, thus creating a brain-to-brain interface (BBI. The implementation was aimed to non-invasively translate the human volunteer's intention to stimulate a rat's brain motor area that is responsible for the tail movement. The volunteer initiated the intention by looking at a strobe light flicker on a computer display, and the degree of synchronization in the electroencephalographic steady-state-visual-evoked-potentials (SSVEP with respect to the strobe frequency was analyzed using a computer. Increased signal amplitude in the SSVEP, indicating the volunteer's intention, triggered the delivery of a burst-mode FUS (350 kHz ultrasound frequency, tone burst duration of 0.5 ms, pulse repetition frequency of 1 kHz, given for 300 msec duration to excite the motor area of an anesthetized rat transcranially. The successful excitation subsequently elicited the tail movement, which was detected by a motion sensor. The interface was achieved at 94.0±3.0% accuracy, with a time delay of 1.59±1.07 sec from the thought-initiation to the creation of the tail movement. Our results demonstrate the feasibility of a computer-mediated BBI that links central neural functions between two biological entities, which may confer unexplored opportunities in the study of neuroscience with potential implications for therapeutic applications.

  4. 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)

  5. 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...

  6. 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

  7. 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.

  8. Multi-modal brain imaging software for guiding invasive treatment of epilepsy

    NARCIS (Netherlands)

    Ossenblok, P.P.W.; Marien, S.; Meesters, S.P.L.; Florack, L.M.J.; Hofman, P.; Schijns, O.E.M.G.; Colon, A.

    2017-01-01

    Purpose: The surgical treatment of patients with complex epilepsies is changing more and more from open, invasive surgery towards minimally invasive, image guided treatment. Multi-modal brain imaging procedures are developed to delineate preoperatively the region of the brain which is responsible

  9. Conscious brain-to-brain communication in humans using non-invasive technologies.

    Science.gov (United States)

    Grau, Carles; Ginhoux, Romuald; Riera, Alejandro; Nguyen, Thanh Lam; Chauvat, Hubert; Berg, Michel; Amengual, Julià L; Pascual-Leone, Alvaro; Ruffini, Giulio

    2014-01-01

    Human sensory and motor systems provide the natural means for the exchange of information between individuals, and, hence, the basis for human civilization. The recent development of brain-computer interfaces (BCI) has provided an important element for the creation of brain-to-brain communication systems, and precise brain stimulation techniques are now available for the realization of non-invasive computer-brain interfaces (CBI). These technologies, BCI and CBI, can be combined to realize the vision of non-invasive, computer-mediated brain-to-brain (B2B) communication between subjects (hyperinteraction). Here we demonstrate the conscious transmission of information between human brains through the intact scalp and without intervention of motor or peripheral sensory systems. Pseudo-random binary streams encoding words were transmitted between the minds of emitter and receiver subjects separated by great distances, representing the realization of the first human brain-to-brain interface. In a series of experiments, we established internet-mediated B2B communication by combining a BCI based on voluntary motor imagery-controlled electroencephalographic (EEG) changes with a CBI inducing the conscious perception of phosphenes (light flashes) through neuronavigated, robotized transcranial magnetic stimulation (TMS), with special care taken to block sensory (tactile, visual or auditory) cues. Our results provide a critical proof-of-principle demonstration for the development of conscious B2B communication technologies. More fully developed, related implementations will open new research venues in cognitive, social and clinical neuroscience and the scientific study of consciousness. We envision that hyperinteraction technologies will eventually have a profound impact on the social structure of our civilization and raise important ethical issues.

  10. Conscious brain-to-brain communication in humans using non-invasive technologies.

    Directory of Open Access Journals (Sweden)

    Carles Grau

    Full Text Available Human sensory and motor systems provide the natural means for the exchange of information between individuals, and, hence, the basis for human civilization. The recent development of brain-computer interfaces (BCI has provided an important element for the creation of brain-to-brain communication systems, and precise brain stimulation techniques are now available for the realization of non-invasive computer-brain interfaces (CBI. These technologies, BCI and CBI, can be combined to realize the vision of non-invasive, computer-mediated brain-to-brain (B2B communication between subjects (hyperinteraction. Here we demonstrate the conscious transmission of information between human brains through the intact scalp and without intervention of motor or peripheral sensory systems. Pseudo-random binary streams encoding words were transmitted between the minds of emitter and receiver subjects separated by great distances, representing the realization of the first human brain-to-brain interface. In a series of experiments, we established internet-mediated B2B communication by combining a BCI based on voluntary motor imagery-controlled electroencephalographic (EEG changes with a CBI inducing the conscious perception of phosphenes (light flashes through neuronavigated, robotized transcranial magnetic stimulation (TMS, with special care taken to block sensory (tactile, visual or auditory cues. Our results provide a critical proof-of-principle demonstration for the development of conscious B2B communication technologies. More fully developed, related implementations will open new research venues in cognitive, social and clinical neuroscience and the scientific study of consciousness. We envision that hyperinteraction technologies will eventually have a profound impact on the social structure of our civilization and raise important ethical issues.

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Non-invasive Brain Stimulation: A Paradigm Shift in Understanding Brain Oscillations

    Directory of Open Access Journals (Sweden)

    Johannes Vosskuhl

    2018-05-01

    Full Text Available Cognitive neuroscience set out to understand the neural mechanisms underlying cognition. One central question is how oscillatory brain activity relates to cognitive processes. Up to now, most of the evidence supporting this relationship was correlative in nature. This situation changed dramatically with the recent development of non-invasive brain stimulation (NIBS techniques, which open up new vistas for neuroscience by allowing researchers for the first time to validate their correlational theories by manipulating brain functioning directly. In this review, we focus on transcranial alternating current stimulation (tACS, an electrical brain stimulation method that applies sinusoidal currents to the intact scalp of human individuals to directly interfere with ongoing brain oscillations. We outline how tACS can impact human brain oscillations by employing different levels of observation from non-invasive tACS application in healthy volunteers and intracranial recordings in patients to animal studies demonstrating the effectiveness of alternating electric fields on neurons in vitro and in vivo. These findings likely translate to humans as comparable effects can be observed in human and animal studies. Neural entrainment and plasticity are suggested to mediate the behavioral effects of tACS. Furthermore, we focus on mechanistic theories about the relationship between certain cognitive functions and specific parameters of brain oscillaitons such as its amplitude, frequency, phase and phase coherence. For each of these parameters we present the current state of testing its functional relevance by means of tACS. Recent developments in the field of tACS are outlined which include the stimulation with physiologically inspired non-sinusoidal waveforms, stimulation protocols which allow for the observation of online-effects, and closed loop applications of tACS.

  18. 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.

  19. 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.

  20. Invasive and non-invasive brain stimulation for treatment of neuropathic pain in patients with spinal cord injury: a review.

    Science.gov (United States)

    Nardone, Raffaele; Höller, Yvonne; Leis, Stefan; Höller, Peter; Thon, Natasha; Thomschewski, Aljoscha; Golaszewski, Stefan; Brigo, Francesco; Trinka, Eugen

    2014-01-01

    Past evidence has shown that invasive and non-invasive brain stimulation may be effective for relieving central pain. To perform a topical review of the literature on brain neurostimulation techniques in patients with chronic neuropathic pain due to traumatic spinal cord injury (SCI) and to assess the current evidence for their therapeutic efficacy. A MEDLINE search was performed using following terms: "Spinal cord injury", "Neuropathic pain", "Brain stimulation", "Deep brain stimulation" (DBS), "Motor cortex stimulation" (MCS), "Transcranial magnetic stimulation" (TMS), "Transcranial direct current stimulation" (tDCS), "Cranial electrotherapy stimulation" (CES). Invasive neurostimulation therapies, in particular DBS and epidural MCS, have shown promise as treatments for neuropathic and phantom limb pain. However, the long-term efficacy of DBS is low, while MCS has a relatively higher potential with lesser complications that DBS. Among the non-invasive techniques, there is accumulating evidence that repetitive TMS can produce analgesic effects in healthy subjects undergoing laboratory-induced pain and in chronic pain conditions of various etiologies, at least partially and transiently. Another very safe technique of non-invasive brain stimulation - tDCS - applied over the sensory-motor cortex has been reported to decrease pain sensation and increase pain threshold in healthy subjects. CES has also proved to be effective in managing some types of pain, including neuropathic pain in subjects with SCI. A number of studies have begun to use non-invasive neuromodulatory techniques therapeutically to relieve neuropathic pain and phantom phenomena in patients with SCI. However, further studies are warranted to corroborate the early findings and confirm different targets and stimulation paradigms. The utility of these protocols in combination with pharmacological approaches should also be explored.

  1. 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...

  2. What limits the performance of current invasive Brain Machine Interfaces?

    Directory of Open Access Journals (Sweden)

    Gytis eBaranauskas

    2014-04-01

    Full Text Available The concept of a brain-machine interface (BMI or a computer-brain interface is simple: BMI creates a communication pathway for a direct control by brain of an external device. In reality BMIs are very complex devices and only recently the increase in computing power of microprocessors enabled a boom in BMI research that continues almost unabated to this date, the high point being the insertion of electrode arrays into the brains of 5 human patients in a clinical trial run by Cyberkinetics with few other clinical tests still in progress. Meanwhile several EEG-based BMI devices (non-invasive BMIs were launched commercially. Modern electronics and dry electrode technology made possible to drive the cost of some of these devices below few hundred dollars. However, the initial excitement of the direct control by brain waves of a computer or other equipment is dampened by large efforts required for learning, high error rates and slow response speed. All these problems are directly related to low information transfer rates typical for such EEG-based BMIs. In invasive BMIs employing multiple electrodes inserted into the brain one may expect much higher information transfer rates than in EEG-based BMIs because, in theory, each electrode provides an independent information channel. However, although invasive BMIs require more expensive equipment and have ethical problems related to the need to insert electrodes in the live brain, such financial and ethical costs are often not offset by a dramatic improvement in the information transfer rate. Thus the main topic of this review is why in invasive BMIs an apparently much larger information content obtained with multiple extracellular electrodes does not translate into much higher rates of information transfer? This paper explores possible answers to this question by concluding that more research on what movement parameters are encoded by neurons in motor cortex is needed before we can enjoy the next

  3. 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.

  4. Calorie restriction as an anti-invasive therapy for malignant brain cancer in the VM mouse.

    Science.gov (United States)

    Shelton, Laura M; Huysentruyt, Leanne C; Mukherjee, Purna; Seyfried, Thomas N

    2010-07-23

    GBM (glioblastoma multiforme) is the most aggressive and invasive form of primary human brain cancer. We recently developed a novel brain cancer model in the inbred VM mouse strain that shares several characteristics with human GBM. Using bioluminescence imaging, we tested the efficacy of CR (calorie restriction) for its ability to reduce tumour size and invasion. CR targets glycolysis and rapid tumour cell growth in part by lowering circulating glucose levels. The VM-M3 tumour cells were implanted intracerebrally in the syngeneic VM mouse host. Approx. 12-15 days post-implantation, brains were removed and both ipsilateral and contralateral hemispheres were imaged to measure bioluminescence of invading tumour cells. CR significantly reduced the invasion of tumour cells from the implanted ipsilateral hemisphere into the contralateral hemisphere. The total percentage of Ki-67-stained cells within the primary tumour and the total number of blood vessels was also significantly lower in the CR-treated mice than in the mice fed ad libitum, suggesting that CR is anti-proliferative and anti-angiogenic. Our findings indicate that the VM-M3 GBM model is a valuable tool for studying brain tumour cell invasion and for evaluating potential therapeutic approaches for managing invasive brain cancer. In addition, we show that CR can be effective in reducing malignant brain tumour growth and invasion.

  5. Calorie Restriction as an Anti-Invasive Therapy for Malignant Brain Cancer in the VM Mouse

    Directory of Open Access Journals (Sweden)

    Laura M Shelton

    2010-07-01

    Full Text Available GBM (glioblastoma multiforme is the most aggressive and invasive form of primary human brain cancer. We recently developed a novel brain cancer model in the inbred VM mouse strain that shares several characteristics with human GBM. Using bioluminescence imaging, we tested the efficacy of CR (calorie restriction for its ability to reduce tumour size and invasion. CR targets glycolysis and rapid tumour cell growth in part by lowering circulating glucose levels. The VM-M3 tumour cells were implanted intracerebrally in the syngeneic VM mouse host. Approx. 12-15 days post-implantation, brains were removed and both ipsilateral and contralateral hemispheres were imaged to measure bioluminescence of invading tumour cells. CR significantly reduced the invasion of tumour cells from the implanted ipsilateral hemisphere into the contralateral hemisphere. The total percentage of Ki-67-stained cells within the primary tumour and the total number of blood vessels was also significantly lower in the CR-treated mice than in the mice fed ad libitum, suggesting that CR is anti-proliferative and anti-angiogenic. Our findings indicate that the VM-M3 GBM model is a valuable tool for studying brain tumour cell invasion and for evaluating potential therapeutic approaches for managing invasive brain cancer. In addition, we show that CR can be effective in reducing malignant brain tumour growth and invasion.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  7. 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)

  8. Non-invasive assessment of coronary artery bypass graft patency using 16-slice computed tomography angiography

    Directory of Open Access Journals (Sweden)

    Uren Neal G

    2007-06-01

    Full Text Available Abstract Background Invasive coronary angiography is the gold standard means of imaging bypass vessels and carries a small but potentially serious risk of local vascular complications, including myocardial infarction, stroke and death. We evaluated computed tomography as a non-invasive means of assessing graft patency. Methods Fifty patients with previous coronary artery bypass surgery who were listed for diagnostic coronary angiography underwent contrast enhanced computed tomography angiography using a 16-slice computed tomography scanner. Images were retrospectively gated to the electrocardiogram and two dimensional axial, multiplanar and three dimensional reconstructions acquired. Sensitivity, specificity, positive and negative predictive value, accuracy and level of agreement for detection of graft patency by multidetector computed tomography. Results A total of 116 grafts were suitable for analysis. The specificity of CT for the detection of graft patency was 100%, with a sensitivity of 92.8%, positive predictive value 100%, negative predictive value 85.8% and an accuracy of 94.8%. The kappa value of agreement between the two means of measuring graft patency was 0.9. Mean radiation dose was 9.0 ± 7.2 mSv for coronary angiography and 18.5 ± 4 mSv for computed tomography. Pooled analysis of eight studies, incorporating 932 grafts, confirmed a 97% accuracy for the detection of graft patency by multidetector computed tomography. Conclusion Computed tomography is an accurate, rapid and non-invasive method of assessing coronary artery bypass graft patency. However, this was achieved at the expense of an increase in radiation dose.

  9. Smart moves: effects of relative brain size on establishment success of invasive amphibians and reptiles.

    Science.gov (United States)

    Amiel, Joshua J; Tingley, Reid; Shine, Richard

    2011-04-06

    Brain size relative to body size varies considerably among animals, but the ecological consequences of that variation remain poorly understood. Plausibly, larger brains confer increased behavioural flexibility, and an ability to respond to novel challenges. In keeping with that hypothesis, successful invasive species of birds and mammals that flourish after translocation to a new area tend to have larger brains than do unsuccessful invaders. We found the same pattern in ectothermic terrestrial vertebrates. Brain size relative to body size was larger in species of amphibians and reptiles reported to be successful invaders, compared to species that failed to thrive after translocation to new sites. This pattern was found in six of seven global biogeographic realms; the exception (where relatively larger brains did not facilitate invasion success) was Australasia. Establishment success was also higher in amphibian and reptile families with larger relative brain sizes. Future work could usefully explore whether invasion success is differentially associated with enlargement of specific parts of the brain (as predicted by the functional role of the forebrain in promoting behavioural flexibility), or with a general size increase (suggesting that invasion success is facilitated by enhanced perceptual and motor skills, as well as cognitive ability).

  10. 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.)

  11. 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...

  12. Smart Moves: Effects of Relative Brain Size on Establishment Success of Invasive Amphibians and Reptiles

    Science.gov (United States)

    Amiel, Joshua J.; Tingley, Reid; Shine, Richard

    2011-01-01

    Brain size relative to body size varies considerably among animals, but the ecological consequences of that variation remain poorly understood. Plausibly, larger brains confer increased behavioural flexibility, and an ability to respond to novel challenges. In keeping with that hypothesis, successful invasive species of birds and mammals that flourish after translocation to a new area tend to have larger brains than do unsuccessful invaders. We found the same pattern in ectothermic terrestrial vertebrates. Brain size relative to body size was larger in species of amphibians and reptiles reported to be successful invaders, compared to species that failed to thrive after translocation to new sites. This pattern was found in six of seven global biogeographic realms; the exception (where relatively larger brains did not facilitate invasion success) was Australasia. Establishment success was also higher in amphibian and reptile families with larger relative brain sizes. Future work could usefully explore whether invasion success is differentially associated with enlargement of specific parts of the brain (as predicted by the functional role of the forebrain in promoting behavioural flexibility), or with a general size increase (suggesting that invasion success is facilitated by enhanced perceptual and motor skills, as well as cognitive ability). PMID:21494328

  13. Smart moves: effects of relative brain size on establishment success of invasive amphibians and reptiles.

    Directory of Open Access Journals (Sweden)

    Joshua J Amiel

    2011-04-01

    Full Text Available Brain size relative to body size varies considerably among animals, but the ecological consequences of that variation remain poorly understood. Plausibly, larger brains confer increased behavioural flexibility, and an ability to respond to novel challenges. In keeping with that hypothesis, successful invasive species of birds and mammals that flourish after translocation to a new area tend to have larger brains than do unsuccessful invaders. We found the same pattern in ectothermic terrestrial vertebrates. Brain size relative to body size was larger in species of amphibians and reptiles reported to be successful invaders, compared to species that failed to thrive after translocation to new sites. This pattern was found in six of seven global biogeographic realms; the exception (where relatively larger brains did not facilitate invasion success was Australasia. Establishment success was also higher in amphibian and reptile families with larger relative brain sizes. Future work could usefully explore whether invasion success is differentially associated with enlargement of specific parts of the brain (as predicted by the functional role of the forebrain in promoting behavioural flexibility, or with a general size increase (suggesting that invasion success is facilitated by enhanced perceptual and motor skills, as well as cognitive ability.

  14. MR imaging of brain surface structures

    International Nuclear Information System (INIS)

    Katada, Kazuhiro; Anno, Hirofumi; Takesita, Gen; Koga, Sukehiko; Kanno, Tetuo; Sakakibara, Tatuo; Yamada, Kazuhiro; Suzuki, Hirokazu; Saito, Sigeki.

    1989-01-01

    An imaging technique that permits direct and non-invasive visualization of brain surface structures was proposed. This technique (Surface anatomy scanning, SAS) consists of long TE-long TR spin echo sequence, thick slice and surface coil. Initial clinical trials in 31 patients with various cerebral pathology showed excellent visualization of sulci, gyri and major cortical veins on the lateral surface of the brain together with cortical and subcortical lesions. Our preliminary results indicate that the SAS is an effective method for the diagnosis and localization of cortical and subcortical pathology, and the possible application of SAS to the surgical and the radiation therapy planning is sugessted. (author)

  15. Nitrosoureas inhibit the stathmin-mediated migration and invasion of malignant glioma cells.

    Science.gov (United States)

    Liang, Xing-Jie; Choi, Yong; Sackett, Dan L; Park, John K

    2008-07-01

    Malignant gliomas are the most common primary intrinsic brain tumors and are highly lethal. The widespread migration and invasion of neoplastic cells from the initial site of tumor formation into the surrounding brain render these lesions refractory to definitive surgical treatment. Stathmin, a microtubule-destabilizing protein that mediates cell cycle progression, can also regulate directed cell movement. Nitrosoureas, traditionally viewed as DNA alkylating agents, can also covalently modify proteins such as stathmin. We therefore sought to establish a role for stathmin in malignant glioma cell motility, migration, and invasion and determine the effects of nitrosoureas on these cell movement-related processes. Scratch wound-healing recovery, Boyden chamber migration, Matrigel invasion, and organotypic slice invasion assays were performed before and after the down-regulation of cellular stathmin levels and in the absence and presence of sublethal nitrosourea ([1-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea]; CCNU) concentrations. We show that decreases in stathmin expression lead to significant decreases in malignant glioma cell motility, migration, and invasion. CCNU, at a concentration of 10 micromol/L, causes similar significant decreases, even in the absence of any effects on cell viability. The direct inhibition of stathmin by CCNU is likely a contributing factor. These findings suggest that the inhibition of stathmin expression and function may be useful in limiting the spread of malignant gliomas within the brain, and that nitrosoureas may have therapeutic benefits in addition to their antiproliferative effects.

  16. Nitrosoureas Inhibit the Stathmin Mediated Migration and Invasion of Malignant Glioma Cells

    Science.gov (United States)

    Liang, Xing-Jie; Choi, Yong; Sackett, Dan L.; Park, John K.

    2008-01-01

    Malignant gliomas are the most common primary intrinsic brain tumors and are highly lethal. The widespread migration and invasion of neoplastic cells from the initial site of tumor formation into the surrounding brain render these lesions refractory to definitive surgical treatment. Stathmin, a microtubule destabilizing protein that mediates cell cycle progression, can also regulate directed cell movement. Nitrosoureas, traditionally viewed as DNA alkylating agents, can also covalently modify proteins such as stathmin. We therefore sought to establish a role for stathmin in malignant glioma cell motility, migration, and invasion and determine the effects of nitrosoureas on these cell movement related processes. Scratch-wound healing recovery, Boyden chamber migration, Matrigel invasion, and organotypic slice invasion assays were performed before and after the down regulation of cellular stathmin levels and in the absence and presence of sub-lethal nitrosourea (CCNU; [1-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea]) concentrations. We demonstrate that decreases in stathmin expression lead to significant decreases in malignant glioma cell motility, migration, and invasion. CCNU, at a concentration of 10 μM, causes similar significant decreases, even in the absence of any effects on cell viability. The direct inhibition of stathmin by CCNU is likely a contributing factor. These findings suggest that the inhibition of stathmin expression and function may be useful in limiting the spread of malignant gliomas within the brain and that nitrosoureas may have therapeutic benefits in addition to their anti-proliferative effects. PMID:18593927

  17. 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...

  18. 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)

  19. 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.

  20. 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

  1. 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.

  2. 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...

  3. 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

  4. 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.

  5. A novel pre-clinical in vivo mouse model for malignant brain tumor growth and invasion.

    Science.gov (United States)

    Shelton, Laura M; Mukherjee, Purna; Huysentruyt, Leanne C; Urits, Ivan; Rosenberg, Joshua A; Seyfried, Thomas N

    2010-09-01

    Glioblastoma multiforme (GBM) is a rapidly progressive disease of morbidity and mortality and is the most common form of primary brain cancer in adults. Lack of appropriate in vivo models has been a major roadblock to developing effective therapies for GBM. A new highly invasive in vivo GBM model is described that was derived from a spontaneous brain tumor (VM-M3) in the VM mouse strain. Highly invasive tumor cells could be identified histologically on the hemisphere contralateral to the hemisphere implanted with tumor cells or tissue. Tumor cells were highly expressive for the chemokine receptor CXCR4 and the proliferation marker Ki-67 and could be identified invading through the pia mater, the vascular system, the ventricular system, around neurons, and over white matter tracts including the corpus callosum. In addition, the brain tumor cells were labeled with the firefly luciferase gene, allowing for non-invasive detection and quantitation through bioluminescent imaging. The VM-M3 tumor has a short incubation time with mortality occurring in 100% of the animals within approximately 15 days. The VM-M3 brain tumor model therefore can be used in a pre-clinical setting for the rapid evaluation of novel anti-invasive therapies.

  6. Role of KCNMA1 gene in breast cancer invasion and metastasis to brain

    Directory of Open Access Journals (Sweden)

    Couraud Pierre-Olivier

    2009-07-01

    Full Text Available Abstract Background The prognosis for patients with breast tumor metastases to brain is extremely poor. Identification of prognostic molecular markers of the metastatic process is critical for designing therapeutic modalities for reducing the occurrence of metastasis. Although ubiquitously present in most human organs, large-conductance calcium- and voltage-activated potassium channel (BKCa channels are significantly upregulated in breast cancer cells. In this study we investigated the role of KCNMA1 gene that encodes for the pore-forming α-subunit of BKCa channels in breast cancer metastasis and invasion. Methods We performed Global exon array to study the expression of KCNMA1 in metastatic breast cancer to brain, compared its expression in primary breast cancer and breast cancers metastatic to other organs, and validated the findings by RT-PCR. Immunohistochemistry was performed to study the expression and localization of BKCa channel protein in primary and metastatic breast cancer tissues and breast cancer cell lines. We performed matrigel invasion, transendothelial migration and membrane potential assays in established lines of normal breast cells (MCF-10A, non-metastatic breast cancer (MCF-7, non-brain metastatic breast cancer cells (MDA-MB-231, and brain-specific metastatic breast cancer cells (MDA-MB-361 to study whether BKCa channel inhibition attenuates breast tumor invasion and metastasis using KCNMA1 knockdown with siRNA and biochemical inhibition with Iberiotoxin (IBTX. Results The Global exon array and RT-PCR showed higher KCNMA1 expression in metastatic breast cancer in brain compared to metastatic breast cancers in other organs. Our results clearly show that metastatic breast cancer cells exhibit increased BKCa channel activity, leading to greater invasiveness and transendothelial migration, both of which could be attenuated by blocking KCNMA1. Conclusion Determining the relative abundance of BKCa channel expression in breast

  7. Role of KCNMA1 gene in breast cancer invasion and metastasis to brain

    International Nuclear Information System (INIS)

    Khaitan, Divya; Sankpal, Umesh T; Weksler, Babette; Meister, Edward A; Romero, Ignacio A; Couraud, Pierre-Olivier; Ningaraj, Nagendra S

    2009-01-01

    The prognosis for patients with breast tumor metastases to brain is extremely poor. Identification of prognostic molecular markers of the metastatic process is critical for designing therapeutic modalities for reducing the occurrence of metastasis. Although ubiquitously present in most human organs, large-conductance calcium- and voltage-activated potassium channel (BK Ca ) channels are significantly upregulated in breast cancer cells. In this study we investigated the role of KCNMA1 gene that encodes for the pore-forming α-subunit of BK Ca channels in breast cancer metastasis and invasion. We performed Global exon array to study the expression of KCNMA1 in metastatic breast cancer to brain, compared its expression in primary breast cancer and breast cancers metastatic to other organs, and validated the findings by RT-PCR. Immunohistochemistry was performed to study the expression and localization of BK Ca channel protein in primary and metastatic breast cancer tissues and breast cancer cell lines. We performed matrigel invasion, transendothelial migration and membrane potential assays in established lines of normal breast cells (MCF-10A), non-metastatic breast cancer (MCF-7), non-brain metastatic breast cancer cells (MDA-MB-231), and brain-specific metastatic breast cancer cells (MDA-MB-361) to study whether BK Ca channel inhibition attenuates breast tumor invasion and metastasis using KCNMA1 knockdown with siRNA and biochemical inhibition with Iberiotoxin (IBTX). The Global exon array and RT-PCR showed higher KCNMA1 expression in metastatic breast cancer in brain compared to metastatic breast cancers in other organs. Our results clearly show that metastatic breast cancer cells exhibit increased BK Ca channel activity, leading to greater invasiveness and transendothelial migration, both of which could be attenuated by blocking KCNMA1. Determining the relative abundance of BK Ca channel expression in breast cancer metastatic to brain and the mechanism of its

  8. 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.)

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

    Science.gov (United States)

    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.

  10. Non-invasive measurement of brain glycogen by NMR spectroscopy and its application to the study of brain metabolism

    Science.gov (United States)

    Tesfaye, Nolawit; Seaquist, Elizabeth R.; Öz, Gülin

    2011-01-01

    Glycogen is the reservoir for glucose in the brain. Beyond the general agreement that glycogen serves as an energy source in the central nervous system, its exact role in brain energy metabolism has yet to be elucidated. Experiments performed in cell and tissue culture and animals have shown that glycogen content is affected by several factors including glucose, insulin, neurotransmitters, and neuronal activation. The study of in vivo glycogen metabolism has been hindered by the inability to measure glycogen non-invasively, but in the past several years, the development of a non-invasive localized 13C nuclear magnetic resonance (NMR) spectroscopy method has enabled the study of glycogen metabolism in the conscious human. With this technique, 13C-glucose is administered intravenously and its incorporation into and wash-out from brain glycogen is tracked. One application of this method has been to the study of brain glycogen metabolism in humans during hypoglycemia: data have shown that mobilization of brain glycogen is augmented during hypoglycemia and, after a single episode of hypoglycemia, glycogen synthesis rate is increased, suggesting that glycogen stores rebound to levels greater than baseline. Such studies suggest glycogen may serve as a potential energy reservoir in hypoglycemia and may participate in the brain's adaptation to recurrent hypoglycemia and eventual development of hypoglycemia unawareness. Beyond this focused area of study, 13C NMR spectroscopy has a broad potential for application in the study of brain glycogen metabolism and carries the promise of a better understanding of the role of brain glycogen in diabetes and other conditions. PMID:21732401

  11. 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...

  12. 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.)

  13. 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.)

  14. Non-invasive brain stimulation for Parkinson's disease: Current concepts and outlook 2015.

    Science.gov (United States)

    Benninger, David H; Hallett, Mark

    2015-01-01

    In advanced Parkinson's disease (PD), the emergence of symptoms refractory to conventional therapy poses a therapeutic challenge. The success of deep brain stimulation (DBS) and advances in the understanding of the pathophysiology of PD have raised interest in non-invasive brain stimulation as an alternative therapeutic tool. The rationale for its use draws from the concept that reversing abnormalities in brain activity and physiology thought to cause the clinical deficits may restore normal functioning. Currently the best evidence in support of this concept comes from DBS, which improves motor deficits, and modulates brain activity and motor cortex physiology, though whether a causal interaction exists remains largely undetermined. Most trials of non-invasive brain stimulation in PD have applied repetitive transcranial magnetic stimulation (rTMS) targeting the primary motor cortex and cortical areas of the motor circuit. Published studies suggest a possible therapeutic potential of rTMS and transcranial direct current stimulation (tDCS), but clinical effects so far have been small and negligible regarding functional independence and quality of life. Approaches to potentiate the efficacy of rTMS, including increasing stimulation intensity and novel stimulation parameters, derive their rationale from studies of brain physiology. These novel parameters simulate normal firing patterns or act on the hypothesized role of oscillatory activity in the motor cortex and basal ganglia in motor control. There may also be diagnostic potential of TMS in characterizing individual traits for personalized medicine.

  15. 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

  16. Reducing proactive aggression through non-invasive brain stimulation

    Science.gov (United States)

    Schuhmann, Teresa; Lobbestael, Jill; Arntz, Arnoud; Brugman, Suzanne; Sack, Alexander T.

    2015-01-01

    Aggressive behavior poses a threat to human collaboration and social safety. It is of utmost importance to identify the functional mechanisms underlying aggression and to develop potential interventions capable of reducing dysfunctional aggressive behavior already at a brain level. We here experimentally shifted fronto-cortical asymmetry to manipulate the underlying motivational emotional states in both male and female participants while assessing the behavioral effects on proactive and reactive aggression. Thirty-two healthy volunteers received either anodal transcranial direct current stimulation to increase neural activity within right dorsolateral prefrontal cortex, or sham stimulation. Aggressive behavior was measured with the Taylor Aggression Paradigm. We revealed a general gender effect, showing that men displayed more behavioral aggression than women. After the induction of right fronto-hemispheric dominance, proactive aggression was reduced in men. This study demonstrates that non-invasive brain stimulation can reduce aggression in men. This is a relevant and promising step to better understand how cortical brain states connect to impulsive actions and to examine the causal role of the prefrontal cortex in aggression. Ultimately, such findings could help to examine whether the brain can be a direct target for potential supportive interventions in clinical settings dealing with overly aggressive patients and/or violent offenders. PMID:25680991

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

    Science.gov (United States)

    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.

  18. 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.

  19. Non-invasive brain stimulation for the treatment of brain diseases in childhood and adolescence: state of the art, current limits and future challenges

    Directory of Open Access Journals (Sweden)

    Carmelo Mario Vicario

    2013-11-01

    Full Text Available In the last decades interest in application of non-invasive brain stimulation for enhancing neural functions is growing continuously. However, the use of such techniques in pediatric populations remains rather limited and mainly confined to the treatment of severe neurological and psychiatric diseases. In this article we provide a complete review of non-invasive brain stimulation studies conducted in pediatric populations. We also provide a brief discussion about the current limitations and future directions in a field of research still very young and full of issues to be explored.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. 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)

  2. 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...

  3. Effect of Anti-Sticking Nanostructured Surface Coating on Minimally Invasive Electrosurgical Device in Brain.

    Science.gov (United States)

    Cheng, Han-Yi; Ou, Keng-Liang; Chiang, Hsi-Jen; Lin, Li-Hsiang

    2015-10-01

    The purpose of the present study was to examine the extent of thermal injury in the brain after the use of a minimally invasive electrosurgical device with a nanostructured copper-doped diamond-like carbon (DLC-Cu) surface coating. To effectively utilize an electrosurgical device in clinical surgery, it is important to decrease the thermal injury to the adjacent tissues. The surface characteristics and morphology of DLC-Cu thin film was evaluated using a contact angle goniometer, scanning electron microscopy, and atomic force microscopy. Three-dimensional biomedical brain models were reconstructed using magnetic resonance images to simulate the electrosurgical procedure. Results indicated that the temperature was reduced significantly when a minimally invasive electrosurgical device with a DLC-Cu thin film coating (DLC-Cu-SS) was used. Temperatures decreased with the use of devices with increasing film thickness. Thermographic data revealed that surgical temperatures in an animal model were significantly lower with the DLC-Cu-SS electrosurgical device compared to an untreated device. Furthermore, the DLC-Cu-SS device created a relatively small region of injury and lateral thermal range. As described above, the biomedical nanostructured film reduced excessive thermal injury with the use of a minimally invasive electrosurgical device in the brain.

  4. 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

  5. A simple non-invasive method for measuring gross brain size in small live fish with semi-transparent heads

    Directory of Open Access Journals (Sweden)

    Joacim Näslund

    2014-09-01

    Full Text Available This paper describes a non-invasive method for estimating gross brain size in small fish with semi-transparent heads, using system camera equipment. Macro-photographs were taken from above on backlit free-swimming fish undergoing light anaesthesia. From the photographs, the width of the optic tectum was measured. This measure (TeO-measure correlates well with the width of the optic tectum as measured from out-dissected brains in both brown trout fry and zebrafish (Pearson r > 0.90. The TeO-measure also correlates well with overall brain wet weight in brown trout fry (r = 0.90, but less well for zebrafish (r = 0.79. A non-invasive measure makes it possible to quickly assess brain size from a large number of individuals, as well as repeatedly measuring brain size of live individuals allowing calculation of brain growth.

  6. 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...

  7. 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)

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

    Science.gov (United States)

    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.

  9. 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...

  10. Metabolic targeting of lactate efflux by malignant glioma inhibits invasiveness and induces necrosis: an in vivo study.

    Science.gov (United States)

    Colen, Chaim B; Shen, Yimin; Ghoddoussi, Farhad; Yu, Pingyang; Francis, Todd B; Koch, Brandon J; Monterey, Michael D; Galloway, Matthew P; Sloan, Andrew E; Mathupala, Saroj P

    2011-07-01

    Glioblastoma multiforme (GBM) are the most malignant among brain tumors. They are frequently refractory to chemotherapy and radiotherapy with mean patient survival of approximately 6 months, despite surgical intervention. The highly glycolytic nature of glioblastomas describes their propensity to metabolize glucose to lactic acid at an elevated rate. To survive, GBMs efflux lactic acid to the tumor microenvironment through transmembrane transporters denoted monocarboxylate transporters (MCTs). We hypothesized that inhibition of MCT function would impair the glycolytic metabolism and affect both glioma invasiveness and survival. We examined the effect on invasiveness with α-cyano-4-hydroxy-cinnamic acid (ACCA, 4CIN, CHCA), a small-molecule inhibitor of lactate transport, through Matrigel-based and organotypic (brain) slice culture invasive assays using U87-MG and U251-MG glioma cells. We then conducted studies in immunodeficient rats by stereotaxic intracranial implantation of the glioma cells followed by programmed orthotopic application of ACCA through osmotic pumps. Effect on the implanted tumor was monitored by small-animal magnetic resonance imaging. Our assays indicated that glioma invasion was markedly impaired when lactate efflux was inhibited. Convection-enhanced delivery of inhibitor to the tumor bed caused tumor necrosis, with 50% of the animals surviving beyond the experimental end points (3 months after inhibitor exhaustion). Most importantly, control animals did not display any adverse neurologic effects during orthotopic administration of ACCA to brain through programmed delivery. These results indicate the clinical potential of targeting lactate efflux in glioma through delivery of small-molecule inhibitors of MCTs either to the tumor bed or to the postsurgical resection cavity.

  11. Metabolic Targeting of Lactate Efflux by Malignant Glioma Inhibits Invasiveness and Induces Necrosis: An In Vivo Study

    Directory of Open Access Journals (Sweden)

    Chaim B Colen

    2011-07-01

    Full Text Available Glioblastoma multiforme (GBM are the most malignant among brain tumors. They are frequently refractory to chemotherapy and radiotherapy with mean patient survival of approximately 6 months, despite surgical intervention. The highly glycolytic nature of glioblastomas describes their propensity to metabolize glucose to lactic acid at an elevated rate. To survive, GBMs efflux lactic acid to the tumor microenvironment through transmembrane transporters denoted monocarboxylate transporters (MCTs. We hypothesized that inhibition of MCT function would impair the glycolytic metabolism and affect both glioma invasiveness and survival. We examined the effect on invasiveness with α-cyano-4-hydroxy-cinnamic acid (ACCA, 4CIN, CHCA, a small-molecule inhibitor of lactate transport, through Matrigel-based and organotypic (brain slice culture invasive assays using U87-MG and U251-MG glioma cells. We then conducted studies in immunodeficient rats by stereotaxic intracranial implantation of the glioma cells followed by programmed orthotopic application of ACCA through osmotic pumps. Effect on the implanted tumor was monitored by small-animal magnetic resonance imaging. Our assays indicated that glioma invasion was markedly impaired when lactate efflux was inhibited. Convection-enhanced delivery of inhibitor to the tumor bed caused tumor necrosis, with 50% of the animals surviving beyond the experimental end points (3 months after inhibitor exhaustion. Most importantly, control animals did not display any adverse neurologic effects during orthotopic administration of ACCA to brain through programmed delivery. These results indicate the clinical potential of targeting lactate efflux in glioma through delivery of small-molecule inhibitors of MCTs either to the tumor bed or to the postsurgical resection cavity.

  12. A technical guide to tDCS, and related non-invasive brain stimulation tools

    Science.gov (United States)

    Woods, AJ; Antal, A; Bikson, M; Boggio, PS; Brunoni, AR; Celnik, P; Cohen, LG; Fregni, F; Herrmann, CS; Kappenman, ES; Knotkova, H; Liebetanz, D; Miniussi, C; Miranda, PC; Paulus, W; Priori, A; Reato, D; Stagg, C; Wenderoth, N; Nitsche, MA

    2015-01-01

    Transcranial electrical stimulation (tES), including transcranial direct and alternating current stimulation (tDCS, tACS) are non-invasive brain stimulation techniques increasingly used for modulation of central nervous system excitability in humans. Here we address methodological issues required for tES application. This review covers technical aspects of tES, as well as applications like exploration of brain physiology, modelling approaches, tES in cognitive neurosciences, and interventional approaches. It aims to help the reader to appropriately design and conduct studies involving these brain stimulation techniques, understand limitations and avoid shortcomings, which might hamper the scientific rigor and potential applications in the clinical domain. PMID:26652115

  13. 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…

  14. Towards Effective Non-Invasive Brain-Computer Interfaces Dedicated to Gait Rehabilitation Systems

    Directory of Open Access Journals (Sweden)

    Thierry Castermans

    2013-12-01

    Full Text Available In the last few years, significant progress has been made in the field of walk rehabilitation. Motor cortex signals in bipedal monkeys have been interpreted to predict walk kinematics. Epidural electrical stimulation in rats and in one young paraplegic has been realized to partially restore motor control after spinal cord injury. However, these experimental trials are far from being applicable to all patients suffering from motor impairments. Therefore, it is thought that more simple rehabilitation systems are desirable in the meanwhile. The goal of this review is to describe and summarize the progress made in the development of non-invasive brain-computer interfaces dedicated to motor rehabilitation systems. In the first part, the main principles of human locomotion control are presented. The paper then focuses on the mechanisms of supra-spinal centers active during gait, including results from electroencephalography, functional brain imaging technologies [near-infrared spectroscopy (NIRS, functional magnetic resonance imaging (fMRI, positron-emission tomography (PET, single-photon emission-computed tomography (SPECT] and invasive studies. The first brain-computer interface (BCI applications to gait rehabilitation are then presented, with a discussion about the different strategies developed in the field. The challenges to raise for future systems are identified and discussed. Finally, we present some proposals to address these challenges, in order to contribute to the improvement of BCI for gait rehabilitation.

  15. 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....

  16. 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

  17. Metabolic Targeting of Lactate Efflux by Malignant Glioma Inhibits Invasiveness and Induces Necrosis: An In Vivo Study1

    Science.gov (United States)

    Colen, Chaim B; Shen, Yimin; Ghoddoussi, Farhad; Yu, Pingyang; Francis, Todd B; Koch, Brandon J; Monterey, Michael D; Galloway, Matthew P; Sloan, Andrew E; Mathupala, Saroj P

    2011-01-01

    Glioblastoma multiforme (GBM) are the most malignant among brain tumors. They are frequently refractory to chemotherapy and radiotherapy with mean patient survival of approximately 6 months, despite surgical intervention. The highly glycolytic nature of glioblastomas describes their propensity to metabolize glucose to lactic acid at an elevated rate. To survive, GBMs efflux lactic acid to the tumor microenvironment through transmembrane transporters denoted monocarboxylate transporters (MCTs). We hypothesized that inhibition of MCT function would impair the glycolytic metabolism and affect both glioma invasiveness and survival. We examined the effect on invasiveness with α-cyano-4-hydroxy-cinnamic acid (ACCA, 4CIN, CHCA), a small-molecule inhibitor of lactate transport, through Matrigel-based and organotypic (brain) slice culture invasive assays using U87-MG and U251-MG glioma cells. We then conducted studies in immunodeficient rats by stereotaxic intracranial implantation of the glioma cells followed by programmed orthotopic application of ACCA through osmotic pumps. Effect on the implanted tumor was monitored by small-animal magnetic resonance imaging. Our assays indicated that glioma invasion was markedly impaired when lactate efflux was inhibited. Convection-enhanced delivery of inhibitor to the tumor bed caused tumor necrosis, with 50% of the animals surviving beyond the experimental end points (3 months after inhibitor exhaustion). Most importantly, control animals did not display any adverse neurologic effects during orthotopic administration of ACCA to brain through programmed delivery. These results indicate the clinical potential of targeting lactate efflux in glioma through delivery of small-molecule inhibitors of MCTs either to the tumor bed or to the postsurgical resection cavity. PMID:21750656

  18. 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

  19. Facilitate insight by non-invasive brain stimulation.

    Directory of Open Access Journals (Sweden)

    Richard P Chi

    Full Text Available Our experiences can blind us. Once we have learned to solve problems by one method, we often have difficulties in generating solutions involving a different kind of insight. Yet there is evidence that people with brain lesions are sometimes more resistant to this so-called mental set effect. This inspired us to investigate whether the mental set effect can be reduced by non-invasive brain stimulation. 60 healthy right-handed participants were asked to take an insight problem solving task while receiving transcranial direct current stimulation (tDCS to the anterior temporal lobes (ATL. Only 20% of participants solved an insight problem with sham stimulation (control, whereas 3 times as many participants did so (p = 0.011 with cathodal stimulation (decreased excitability of the left ATL together with anodal stimulation (increased excitability of the right ATL. We found hemispheric differences in that a stimulation montage involving the opposite polarities did not facilitate performance. Our findings are consistent with the theory that inhibition to the left ATL can lead to a cognitive style that is less influenced by mental templates and that the right ATL may be associated with insight or novel meaning. Further studies including neurophysiological imaging are needed to elucidate the specific mechanisms leading to the enhancement.

  20. Reactivity of dogs' brain oscillations to visual stimuli measured with non-invasive electroencephalography.

    Directory of Open Access Journals (Sweden)

    Miiamaaria V Kujala

    Full Text Available Studying cognition of domestic dogs has gone through a renaissance within the last decades. However, although the behavioral studies of dogs are beginning to be common in the field of animal cognition, the neural events underlying cognition remain unknown. Here, we employed a non-invasive electroencephalography, with adhesive electrodes attached to the top of the skin, to measure brain activity of from 8 domestic dogs (Canis familiaris while they stayed still to observe photos of dog and human faces. Spontaneous oscillatory activity of the dogs, peaking in the sensors over the parieto-occipital cortex, was suppressed statistically significantly during visual task compared with resting activity at the frequency of 15-30 Hz. Moreover, a stimulus-induced low-frequency (~2-6 Hz suppression locked to the stimulus onset was evident at the frontal sensors, possibly reflecting a motor rhythm guiding the exploratory eye movements. The results suggest task-related reactivity of the macroscopic oscillatory activity in the dog brain. To our knowledge, the study is the first to reveal non-invasively measured reactivity of brain electrophysiological oscillations in healthy dogs, and it has been based purely on positive operant conditional training, without the need for movement restriction or medication.

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

    Directory of Open Access Journals (Sweden)

    Laurent Chazalviel

    2016-01-01

    Full Text Available 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 oxygen diffusion effects of NBO and HBO on acute ischemic stroke independently of their effects at the vascular level, we used acute brain slices exposed to oxygen and glucose deprivation, an ex vivo model of brain ischemia that allows investigating the acute effects of NBO (partial pressure of oxygen (pO 2 = 1 atmospheres absolute (ATA = 0.1 MPa and HBO (pO 2 = 2.5 ATA = 0.25 MPa through tissue oxygenation on ischemia-induced cell injury as measured by the release of lactate dehydrogenase. We found that HBO, but not NBO, reduced oxygen and glucose deprivation-induced cell injury, indicating that passive tissue oxygenation (i.e. without vascular support of the brain parenchyma requires oxygen partial pressure higher than 1 ATA.

  2. 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...

  3. 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)

  4. Adolescent Kawasaki disease: usefulness of 64-slice CT coronary angiography for follow-up investigation

    Energy Technology Data Exchange (ETDEWEB)

    Carbone, Iacopo; Cannata, David; Algeri, Emanuela; Galea, Nicola; Napoli, Alessandro; Catalano, Carlo; Passariello, Roberto; Francone, Marco [Sapienza University of Rome, Department of Radiological, Onchological and Anatomopathological Sciences, Policlinico Umberto I, Rome (Italy); De Zorzi, Andrea [Bambino Gesu Hospital, Cardiology Division, Rome (Italy); Bosco, Giovanna; D' Agostino, Rita [Sapienza University of Rome, Unit of Paediatric Cardiology, Policlinico Umberto I, Rome (Italy); Menezes, Leon [University College of London, Institute of Nuclear Medicine, London (United Kingdom)

    2011-09-15

    Kawasaki disease (KD) is a systemic vasculitis that mainly affects coronary arteries in children, and requires regular follow-up from the time of diagnosis. To evaluate the feasibility of 64-slice CT angiography (CTA) for follow-up of patients with KD using previously performed invasive catheter coronary angiography (CCA) as reference standard. The study group comprised 12 patients (age 17.6 {+-} 2.9 years, mean{+-}SD) with a diagnosis of KD and a previously performed CCA (interval, 32.6 {+-} 13.5 months) who underwent 64-slice cardiac CTA. The quality of the images for establishing the presence of coronary abnormalities was determined by two observers. The CTA findings were compared with those from the prior CCA. Adequate image quality was obtained in all patients. Mean effective dose for CTA was 6.56 {+-} 0.95 mSv. CTA allowed accurate identification, characterization and measurement of all coronary aneurysms (n = 32), stenoses (n = 3) and occlusions (n = 9) previously demonstrated by CCA. One patient with disease progression went on to have percutaneous coronary intervention. Coronary lesions were reliably evaluated by 64-slice CTA in the follow-up of compliant patients with KD, reducing the need for repeated diagnostic invasive CCA. Hence, in an adequately selected patient population, the role of CCA could be limited almost only to therapeutic procedures. (orig.)

  5. 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)

  6. 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...

  7. Comparison of 64-slice computed tomography angiography and coronary angiography for the detection and assessment of coronary artery disease in patients with angina: A systematic review

    International Nuclear Information System (INIS)

    Powell, H.; Cosson, P.

    2013-01-01

    Background: Coronary artery disease (CAD) is the leading cause of death in Western countries. It presents itself in various ways, the commonest being angina. According to the Royal College of Radiologist referral guidelines, Coronary Angiography (CA) is currently the gold standard for diagnosis and evaluation of CAD. However, due to the invasive nature and expense of CA there is a perceived need for a primary non-invasive imaging modality to supersede it. Computed tomography angiography (CTA), utilising 64-slice technology, may be a less invasive alternative to CA. Aim: To consider the research evidence for the current gold standard diagnostic test for CAD. Specifically, which is more sensitive and specific for detecting CAD in patients with angina; 64-slice CTA or CA? Inclusion Criteria: Prospective, non-randomised control trials and diagnostic accuracy studies comparing 64-slice CTA and CA were included. Participants were adults with angina with suspected or known CAD. Method: An electronic search of the databases; AMED, CINAHL, Cochrane Library, EMBASE, MEDLINE and Science Direct, was conducted between January 2004 and April 2012. Secondary hand-searching of grey literature was undertaken. Two reviewers independently determined studies for inclusion, assessed quality, using SIGN50, and extracted data. Diagnostic value of 64-slice CTA and CA was compared and analysed at patient and segment level. Results: Ten studies were included in the critical review enrolling 1188 patients. At patient level sensitivity for 64-slice CTA ranged from 88% to 100%, specificity 64–92%, PPV 86–97% and NPV 76.9–100%. At segment level sensitivity for 64-slice CTA ranged from 73% to 100%, specificity 83–98%, PPV 47–90% and NPV 89–100% Conclusion: At both patient and segment level, 64-slice CTA is a highly sensitive and specific non-invasive alternative to CA for diagnosis of significant stenosis in patients with angina. For standalone diagnosis of CAD current research would

  8. BrainStorm: a psychosocial game suite design for non-invasive cross-generational cognitive capabilities data collection

    Science.gov (United States)

    Ahmad, Faizan; Chen, Yiqiang; Hu, Lisha; Wang, Shuangquan; Wang, Jindong; Chen, Zhenyu; Jiang, Xinlong; Shen, Jianfei

    2017-11-01

    Currently available traditional as well as videogame-based cognitive assessment techniques are inappropriate due to several reasons. This paper presents a novel psychosocial game suite, BrainStorm, for non-invasive cross-generational cognitive capabilities data collection, which additionally provides cross-generational social support. A motivation behind the development of presented game suite is to provide an entertaining and exciting platform for its target users in order to collect gameplay-based cognitive capabilities data in a non-invasive manner. An extensive evaluation of the presented game suite demonstrated high acceptability and attraction for its target users. Besides, the data collection process is successfully reported as transparent and non-invasive.

  9. 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.

  10. Non-invasive electrical and magnetic stimulation of the brain, spinal cord, roots and peripheral nerves

    DEFF Research Database (Denmark)

    Rossini, P M; Burke, D; Chen, R

    2015-01-01

    These guidelines provide an up-date of previous IFCN report on "Non-invasive electrical and magnetic stimulation of the brain, spinal cord and roots: basic principles and procedures for routine clinical application" (Rossini et al., 1994). A new Committee, composed of international experts, some...

  11. All-optical functional synaptic connectivity mapping in acute brain slices using the calcium integrator CaMPARI.

    Science.gov (United States)

    Zolnik, Timothy A; Sha, Fern; Johenning, Friedrich W; Schreiter, Eric R; Looger, Loren L; Larkum, Matthew E; Sachdev, Robert N S

    2017-03-01

    The genetically encoded fluorescent calcium integrator calcium-modulated photoactivatable ratiobetric integrator (CaMPARI) reports calcium influx induced by synaptic and neural activity. Its fluorescence is converted from green to red in the presence of violet light and calcium. The rate of conversion - the sensitivity to activity - is tunable and depends on the intensity of violet light. Synaptic activity and action potentials can independently initiate significant CaMPARI conversion. The level of conversion by subthreshold synaptic inputs is correlated to the strength of input, enabling optical readout of relative synaptic strength. When combined with optogenetic activation of defined presynaptic neurons, CaMPARI provides an all-optical method to map synaptic connectivity. The calcium-modulated photoactivatable ratiometric integrator (CaMPARI) is a genetically encoded calcium integrator that facilitates the study of neural circuits by permanently marking cells active during user-specified temporal windows. Permanent marking enables measurement of signals from large swathes of tissue and easy correlation of activity with other structural or functional labels. One potential application of CaMPARI is labelling neurons postsynaptic to specific populations targeted for optogenetic stimulation, giving rise to all-optical functional connectivity mapping. Here, we characterized the response of CaMPARI to several common types of neuronal calcium signals in mouse acute cortical brain slices. Our experiments show that CaMPARI is effectively converted by both action potentials and subthreshold synaptic inputs, and that conversion level is correlated to synaptic strength. Importantly, we found that conversion rate can be tuned: it is linearly related to light intensity. At low photoconversion light levels CaMPARI offers a wide dynamic range due to slower conversion rate; at high light levels conversion is more rapid and more sensitive to activity. Finally, we employed Ca

  12. 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.

  13. 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...

  14. Diagnostic potential of virtual bronchoscopy: advantages in comparison with axial CT slices, MPR and mIP?

    International Nuclear Information System (INIS)

    Rapp-Bernhardt, U.; Doehring, W.; Bernhardt, T.M.; Welte, T.; Kropf, S.

    2000-01-01

    The aim of this study was to evaluate the diagnostic potential of virtual endoscopy (VE) and to compare it with axial CT slices, multiplanar reconstructions (MPR), minimal intensity projections (mIP), and bronchoscopy in patients diagnosed with bronchogenic carcinoma. Thirty patients underwent a spiral CT. Axial CT images were transferred to an Onyx workstation (Silicon Graphics, Sun Microsystems, Mountain View, Calif.) for performing virtual endoscopy. Accuracy for this procedure was tested by three radiologists on a monitor in comparison with axial CT slices, MPR, mIP, and bronchoscopy concerning the localization and degree of stenoses. Endoluminal tumors were identified by virtual bronchoscopy with no statistically significant difference of localization or grading of stenosis in comparison with bronchoscopy, axial CT slices, MPR and mIP. Axial CT slices, MPR, and mIP showed poorer results with over- or underestimation of stenoses compared with VE and bronchoscopy. Passing of stenoses was only possible with VE in 5 patients. Virtual endoscopy is a non-invasive method for identification of endoluminal tumors and is comparable to real bronchoscopy. (orig.)

  15. Diagnostic potential of virtual bronchoscopy: advantages in comparison with axial CT slices, MPR and mIP?

    Energy Technology Data Exchange (ETDEWEB)

    Rapp-Bernhardt, U.; Doehring, W.; Bernhardt, T.M. [Department of Diagnostic Radiology, Otto-von-Guericke University, Magdeburg (Germany); Welte, T. [Department of Cardiology, Angiology, and Pneumology, Otto-von-Guericke University, Magdeburg (Germany); Kropf, S. [Department of Biometrics and Medical Informatics, Otto-von-Guericke University, Magdeburg (Germany)

    2000-06-01

    The aim of this study was to evaluate the diagnostic potential of virtual endoscopy (VE) and to compare it with axial CT slices, multiplanar reconstructions (MPR), minimal intensity projections (mIP), and bronchoscopy in patients diagnosed with bronchogenic carcinoma. Thirty patients underwent a spiral CT. Axial CT images were transferred to an Onyx workstation (Silicon Graphics, Sun Microsystems, Mountain View, Calif.) for performing virtual endoscopy. Accuracy for this procedure was tested by three radiologists on a monitor in comparison with axial CT slices, MPR, mIP, and bronchoscopy concerning the localization and degree of stenoses. Endoluminal tumors were identified by virtual bronchoscopy with no statistically significant difference of localization or grading of stenosis in comparison with bronchoscopy, axial CT slices, MPR and mIP. Axial CT slices, MPR, and mIP showed poorer results with over- or underestimation of stenoses compared with VE and bronchoscopy. Passing of stenoses was only possible with VE in 5 patients. Virtual endoscopy is a non-invasive method for identification of endoluminal tumors and is comparable to real bronchoscopy. (orig.)

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. Using non-invasive brain stimulation to augment motor training-induced plasticity

    Directory of Open Access Journals (Sweden)

    Pascual-Leone Alvaro

    2009-03-01

    Full Text Available Abstract Therapies for motor recovery after stroke or traumatic brain injury are still not satisfactory. To date the best approach seems to be the intensive physical therapy. However the results are limited and functional gains are often minimal. The goal of motor training is to minimize functional disability and optimize functional motor recovery. This is thought to be achieved by modulation of plastic changes in the brain. Therefore, adjunct interventions that can augment the response of the motor system to the behavioural training might be useful to enhance the therapy-induced recovery in neurological populations. In this context, noninvasive brain stimulation appears to be an interesting option as an add-on intervention to standard physical therapies. Two non-invasive methods of inducing electrical currents into the brain have proved to be promising for inducing long-lasting plastic changes in motor systems: transcranial magnetic stimulation (TMS and transcranial direct current stimulation (tDCS. These techniques represent powerful methods for priming cortical excitability for a subsequent motor task, demand, or stimulation. Thus, their mutual use can optimize the plastic changes induced by motor practice, leading to more remarkable and outlasting clinical gains in rehabilitation. In this review we discuss how these techniques can enhance the effects of a behavioural intervention and the clinical evidence to date.

  1. 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

  2. Cardiac CT angiography after coronary artery surgery in children using 64-slice CT scan

    International Nuclear Information System (INIS)

    Marini, Davide; Agnoletti, Gabriella; Brunelle, Francis; Sidi, Daniel; Bonnet, Damien; Ou, Phalla

    2009-01-01

    Objective: The purpose of this study was to compare the diagnostic accuracy of 64-slice CT with that of invasive angiography in the detection of graft and/or coronary angioplasty stenosis in children who had undergone coronary artery surgery. Population and methods: Fifteen consecutive children (8 male and 7 female; age 9.2 ± 6.1 years) underwent 64-slice CT because of chest pain or ECG changes mean 4.8 ± 3.7 years after surgical coronary artery surgery; 10 patients had coronary angioplasty using a patch from the saphenous vein, four had mammary artery bypass, and one had saphenous vein bypass. Six main segments of the coronary arteries and all the bypass graft considered as a single segment were analyzed and compared with invasive angiography used as the reference standard. Results: CT correctly identified the four children with coronary angioplasty and mammary graft lesions that were confirmed by conventional angiography: one patient had a significant stenosis (>50% stenosis) at the mammary bypass graft anastomosis site; three other had non-significant stenosis (<50% stenosis) including a mild lesion of the saphenous vein patch in two patients and a mild lesion at the anastomosis site of the mammary bypass in one. All segments identified as normal by CT in the other 11 children were also found to be normal by conventional angiography. Conclusion: In centers expert in this technique, 64-slice CT scanning is a promising, rapid, and useful diagnostic technique for evaluating both coronary angioplasty and bypass graft lesions in children who had undergone coronary artery surgery.

  3. Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives

    DEFF Research Database (Denmark)

    Bergmann, Til Ole; Karabanov, Anke; Hartwigsen, Gesa

    2016-01-01

    Non-invasive transcranial brain stimulation (NTBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial current stimulation (TCS) are important tools in human systems and cognitive neuroscience because they are able to reveal the relevance of certain brain structures...... are technically demanding. We argue that the benefit from this combination is twofold. Firstly, neuroimaging and electrophysiology can inform subsequent NTBS, providing the required information to optimize where, when, and how to stimulate the brain. Information can be achieved both before and during the NTBS...... experiment, requiring consecutive and concurrent applications, respectively. Secondly, neuroimaging and electrophysiology can provide the readout for neural changes induced by NTBS. Again, using either concurrent or consecutive applications, both "online" NTBS effects immediately following the stimulation...

  4. 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.

  5. Non-invasive, MRI-compatible fibreoptic device for functional near-IR reflectometry of human brain

    International Nuclear Information System (INIS)

    Sorvoja, H.S.S.; Myllylae, T S; Myllylae, Risto A; Kirillin, M Yu; Sergeeva, Ekaterina A; Elseoud, A A; Nikkinen, J; Tervonen, O; Kiviniemi, V

    2011-01-01

    A non-invasive device for measuring blood oxygen variations in human brain is designed, implemented, and tested for MRI compatibility. The device is based on principles of near-IR reflectometry; power LEDs serve as sources of probing radiation delivered to patient skin surface through optical fibres. Numerical Monte Carlo simulations of probing radiation propagation in a multilayer brain model are performed to evaluate signal levels at different source - detector separations at three operation wavelengths and an additional wavelength of 915 nm. It is shown that the device can be applied for brain activity studies using power LEDs operating at 830 and 915 nm, while employment of wavelength of 660 nm requires an increased probing power. Employment of the wavelength of 592 nm in the current configuration is unreasonable. (application of lasers and laser-optical methods in life sciences)

  6. 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.

  7. 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

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

    Science.gov (United States)

    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

  9. 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).***

  10. Non-invasive brain stimulation of the aging brain: State of the art and future perspectives.

    Science.gov (United States)

    Tatti, Elisa; Rossi, Simone; Innocenti, Iglis; Rossi, Alessandro; Santarnecchi, Emiliano

    2016-08-01

    Favored by increased life expectancy and reduced birth rate, worldwide demography is rapidly shifting to older ages. The golden age of aging is not only an achievement but also a big challenge because of the load of the elderly on social and medical health care systems. Moreover, the impact of age-related decline of attention, memory, reasoning and executive functions on self-sufficiency emphasizes the need of interventions to maintain cognitive abilities at a useful degree in old age. Recently, neuroscientific research explored the chance to apply Non-Invasive Brain Stimulation (NiBS) techniques (as transcranial electrical and magnetic stimulation) to healthy aging population to preserve or enhance physiologically-declining cognitive functions. The present review will update and address the current state of the art on NiBS in healthy aging. Feasibility of NiBS techniques will be discussed in light of recent neuroimaging (either structural or functional) and neurophysiological models proposed to explain neural substrates of the physiologically aging brain. Further, the chance to design multidisciplinary interventions to maximize the efficacy of NiBS techniques will be introduced as a necessary future direction. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Flat slices in Minkowski space

    Science.gov (United States)

    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.

  12. 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...

  13. Workbench surface editor of brain cortical surface

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  15. Synchronisation signatures in the listening brain: a perspective from non-invasive neuroelectrophysiology.

    Science.gov (United States)

    Weisz, Nathan; Obleser, Jonas

    2014-01-01

    Human magneto- and electroencephalography (M/EEG) are capable of tracking brain activity at millisecond temporal resolution in an entirely non-invasive manner, a feature that offers unique opportunities to uncover the spatiotemporal dynamics of the hearing brain. In general, precise synchronisation of neural activity within as well as across distributed regions is likely to subserve any cognitive process, with auditory cognition being no exception. Brain oscillations, in a range of frequencies, are a putative hallmark of this synchronisation process. Embedded in a larger effort to relate human cognition to brain oscillations, a field of research is emerging on how synchronisation within, as well as between, brain regions may shape auditory cognition. Combined with much improved source localisation and connectivity techniques, it has become possible to study directly the neural activity of auditory cortex with unprecedented spatio-temporal fidelity and to uncover frequency-specific long-range connectivities across the human cerebral cortex. In the present review, we will summarise recent contributions mainly of our laboratories to this emerging domain. We present (1) a more general introduction on how to study local as well as interareal synchronisation in human M/EEG; (2) how these networks may subserve and influence illusory auditory perception (clinical and non-clinical) and (3) auditory selective attention; and (4) how oscillatory networks further reflect and impact on speech comprehension. This article is part of a Special Issue entitled Human Auditory Neuroimaging. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Portable non-invasive brain-computer interface: challenges and opportunities of optical modalities

    Science.gov (United States)

    Scholl, Clara A.; Hendrickson, Scott M.; Swett, Bruce A.; Fitch, Michael J.; Walter, Erich C.; McLoughlin, Michael P.; Chevillet, Mark A.; Blodgett, David W.; Hwang, Grace M.

    2017-05-01

    The development of portable non-invasive brain computer interface technologies with higher spatio-temporal resolution has been motivated by the tremendous success seen with implanted devices. This talk will discuss efforts to overcome several major obstacles to viability including approaches that promise to improve spatial and temporal resolution. Optical approaches in particular will be highlighted and the potential benefits of both Blood-Oxygen Level Dependent (BOLD) and Fast Optical Signal (FOS) will be discussed. Early-stage research into the correlations between neural activity and FOS will be explored.

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

    Science.gov (United States)

    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.

  18. 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

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

    Science.gov (United States)

    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.

  20. 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

  1. 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.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. 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...

  5. 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.

  6. Brain Volume Estimation Enhancement by Morphological Image Processing Tools

    Directory of Open Access Journals (Sweden)

    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.

  7. A non-invasive method for fractionated steriotactic irradiation of brain tumors with linear accelerator

    International Nuclear Information System (INIS)

    Hariz, M.I.; Laitinen, L.V.; Henriksson, R.; Saeterborg, N.-E.; Loefroth, P.-O.

    1990-01-01

    A new technique for fractionated stereotactic irradiation of intracranial lesions is described. The treatment is based on a versatile, non-invasive interface for stereotactic localization of the brain target imaged by computed tomography (CT), angiography or magnetic resonance tomography (MRT), and subsequent repetitive stereotactic irradiation of the target using a linear accelerator. The fractionation of the stereotactic irradiation was intended to meet the requirements of the basic principles of radiobiology. The radiophysical evaluation using phantoms, and the clinical results in a small number of patients, demonstrated a good reproducibilit between repeated positionings of the target in the isocenter of the accelerator, and a high degree of accuracy in the treatment of brain lesions. (authors). 28 refs.; 11 figs.; 1 tab

  8. 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.

  9. EGFRvIII-specific chimeric antigen receptor T cells migrate to and kill tumor deposits infiltrating the brain parenchyma in an invasive xenograft model of glioblastoma.

    Science.gov (United States)

    Miao, Hongsheng; Choi, Bryan D; Suryadevara, Carter M; Sanchez-Perez, Luis; Yang, Shicheng; De Leon, Gabriel; Sayour, Elias J; McLendon, Roger; Herndon, James E; Healy, Patrick; Archer, Gary E; Bigner, Darell D; Johnson, Laura A; Sampson, John H

    2014-01-01

    Glioblastoma (GBM) is the most common primary malignant brain tumor in adults and is uniformly lethal. T-cell-based immunotherapy offers a promising platform for treatment given its potential to specifically target tumor tissue while sparing the normal brain. However, the diffuse and infiltrative nature of these tumors in the brain parenchyma may pose an exceptional hurdle to successful immunotherapy in patients. Areas of invasive tumor are thought to reside behind an intact blood brain barrier, isolating them from effective immunosurveillance and thereby predisposing the development of "immunologically silent" tumor peninsulas. Therefore, it remains unclear if adoptively transferred T cells can migrate to and mediate regression in areas of invasive GBM. One barrier has been the lack of a preclinical mouse model that accurately recapitulates the growth patterns of human GBM in vivo. Here, we demonstrate that D-270 MG xenografts exhibit the classical features of GBM and produce the diffuse and invasive tumors seen in patients. Using this model, we designed experiments to assess whether T cells expressing third-generation chimeric antigen receptors (CARs) targeting the tumor-specific mutation of the epidermal growth factor receptor, EGFRvIII, would localize to and treat invasive intracerebral GBM. EGFRvIII-targeted CAR (EGFRvIII+ CAR) T cells demonstrated in vitro EGFRvIII antigen-specific recognition and reactivity to the D-270 MG cell line, which naturally expresses EGFRvIII. Moreover, when administered systemically, EGFRvIII+ CAR T cells localized to areas of invasive tumor, suppressed tumor growth, and enhanced survival of mice with established intracranial D-270 MG tumors. Together, these data demonstrate that systemically administered T cells are capable of migrating to the invasive edges of GBM to mediate antitumor efficacy and tumor regression.

  10. EGFRvIII-specific chimeric antigen receptor T cells migrate to and kill tumor deposits infiltrating the brain parenchyma in an invasive xenograft model of glioblastoma.

    Directory of Open Access Journals (Sweden)

    Hongsheng Miao

    Full Text Available Glioblastoma (GBM is the most common primary malignant brain tumor in adults and is uniformly lethal. T-cell-based immunotherapy offers a promising platform for treatment given its potential to specifically target tumor tissue while sparing the normal brain. However, the diffuse and infiltrative nature of these tumors in the brain parenchyma may pose an exceptional hurdle to successful immunotherapy in patients. Areas of invasive tumor are thought to reside behind an intact blood brain barrier, isolating them from effective immunosurveillance and thereby predisposing the development of "immunologically silent" tumor peninsulas. Therefore, it remains unclear if adoptively transferred T cells can migrate to and mediate regression in areas of invasive GBM. One barrier has been the lack of a preclinical mouse model that accurately recapitulates the growth patterns of human GBM in vivo. Here, we demonstrate that D-270 MG xenografts exhibit the classical features of GBM and produce the diffuse and invasive tumors seen in patients. Using this model, we designed experiments to assess whether T cells expressing third-generation chimeric antigen receptors (CARs targeting the tumor-specific mutation of the epidermal growth factor receptor, EGFRvIII, would localize to and treat invasive intracerebral GBM. EGFRvIII-targeted CAR (EGFRvIII+ CAR T cells demonstrated in vitro EGFRvIII antigen-specific recognition and reactivity to the D-270 MG cell line, which naturally expresses EGFRvIII. Moreover, when administered systemically, EGFRvIII+ CAR T cells localized to areas of invasive tumor, suppressed tumor growth, and enhanced survival of mice with established intracranial D-270 MG tumors. Together, these data demonstrate that systemically administered T cells are capable of migrating to the invasive edges of GBM to mediate antitumor efficacy and tumor regression.

  11. The virtual slice setup.

    Science.gov (United States)

    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.

  12. Determining the proportion of coronary segments assessable on 16-slice CT coronary angiography: a brief report

    International Nuclear Information System (INIS)

    Soon, K. H.; Cox, N.; Eccleston, D.; Lim, Y.; Chaitowitz, I.; Bell, K. W.; Kelly, A-M.

    2007-01-01

    Computed tomography coronary angiography (CT-CA) is becoming a popular non-invasive coronary imaging method. We aimed to determine the proportion of coronary segments assessable on a 16-slice CT in comparison with conventional selective coronary angiography (SCA). We identified all patients who had both 16-slice CT-CA and recent SCA (less than 12 months) from March 2004 to July 2005. Two CT reporters blinded to SCA independently classified coronary segment assessability on CT-CA. A cardiologist blinded to CT findings classified assess-ability of coronary segments on SCA. Data were analysed using descriptive statistics and proportion of agreement. Ninety-five study pairs were included in the analysis. Of those, 1161 coronary segments were deemed assessable on SCA and 1103 segments (95%) were also assessable on CT-CA. Nonassessable segments on CT-CA were predominantly in the distal segments and branches of coronary arteries. Reasons for nonassessability were small calibre (48.3%), motion artefacts (20.7%) and poorly reconstructed segments (22.4%). The 16-slice CT was able to assess a high proportion of but not all coronary segments. Nonassessable segments were predominantly distal segments or branches of coronary arteries. Motion artefacts due to heart-rate changes, small calibre and poorly reconstructed images were main causes of nonassessability on 16-slice CT-CA

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

  15. Multi-slice and dual-source CT in cardiac imaging. Principles - protocols - indications - outlook. 2. ed.

    International Nuclear Information System (INIS)

    Ohnesorge, B.M.; Flohr, T.G.; Becker, C.R.; Reiser, M.F.; Knez, A

    2007-01-01

    Cardiac diseases, and in particular coronary artery disease, are the leading cause of death and morbidity in industrialized countries. The development of non-invasive imaging techniques for the heart and the coronary arteries has been considered a key element in improving patient care. A breakthrough in cardiac imaging using CT occurred in 1998, with the introduction of multi-slice computed tomography (CT). Since then, amazing advances in performance have taken place with scanners that acquire up to 64 slices per rotation. This book discusses the state-of-the-art developments in multi-slice CT for cardiac imaging as well as those that can be anticipated in the future. It serves as a comprehensive work that covers all aspects of this technology, from the technical fundamentals and image evaluation all the way to clinical indications and protocol recommendations. This fully reworked second edition draws on the most recent clinical experience obtained with 16- and 64-slice CT scanners by world-leading experts from Europe and the United States. It also includes ''hands-on'' experience in the form of 10 representative clinical case studies, which are included on the accompanying CD. As a further highlight, the latest results of the very recently introduced dual-source CT, which may soon represent the CT technology of choice for cardiac applications, are presented. This book will not only convince the reader that multi-slice cardiac CT has arrived in clinical practice, it will also make a significant contribution to the education of radiologists, cardiologists, technologists, and physicists-whether newcomers, experienced users, or researchers. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Stereological estimation of nuclear mean volume in invasive meningiomas

    DEFF Research Database (Denmark)

    Madsen, C; Schrøder, H D

    1996-01-01

    A stereological estimation of nuclear mean volume in bone and brain invasive meningiomas was made. For comparison the nuclear mean volume of benign meningiomas was estimated. The aim was to investigate whether this method could discriminate between these groups. We found that the nuclear mean...... volume in the bone and brain invasive meningiomas was larger than in the benign tumors. The difference was significant and moreover it was seen that there was no overlap between the two groups. In the bone invasive meningiomas the nuclear mean volume appeared to be larger inside than outside the bone....... No significant difference in nuclear mean volume was found between brain and bone invasive meningiomas. The results demonstrate that invasive meningiomas differ from benign meningiomas by an objective stereological estimation of nuclear mean volume (p

  18. Integrated semiconductor optical sensors for chronic, minimally-invasive imaging of brain function.

    Science.gov (United States)

    Lee, Thomas T; Levi, Ofer; Cang, Jianhua; Kaneko, Megumi; Stryker, Michael P; Smith, Stephen J; Shenoy, Krishna V; Harris, James S

    2006-01-01

    Intrinsic optical signal (IOS) imaging is a widely accepted technique for imaging brain activity. We propose an integrated device consisting of interleaved arrays of gallium arsenide (GaAs) based semiconductor light sources and detectors operating at telecommunications wavelengths in the near-infrared. Such a device will allow for long-term, minimally invasive monitoring of neural activity in freely behaving subjects, and will enable the use of structured illumination patterns to improve system performance. In this work we describe the proposed system and show that near-infrared IOS imaging at wavelengths compatible with semiconductor devices can produce physiologically significant images in mice, even through skull.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  2. Non-invasive determination of the absorption coefficient of the brain from time-resolved reflectance using a neural network

    International Nuclear Information System (INIS)

    Jaeger, Marion; Kienle, Alwin

    2011-01-01

    We investigated the performance of a neural network for derivation of the absorption coefficient of the brain from simulated non-invasive time-resolved reflectance measurements on the head. A five-layered geometry was considered assuming that the optical properties (except the absorption coefficient of the brain) and the thickness of all layers were known with an uncertainty. A solution of the layered diffusion equation was used to train the neural network. We determined the absorption coefficient of the brain with an RMS error of <6% from reflectance data at a single distance calculated by diffusion theory. By applying the neural network to reflectance curves obtained from Monte Carlo simulations, similar errors were found. (note)

  3. 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)

  4. 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)

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

    Science.gov (United States)

    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.

  6. 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.)

  7. 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.)

  8. Inter-subject and Inter-session Variability of Plasticity Induction by Non-invasive Brain Stimulation

    DEFF Research Database (Denmark)

    Ziemann, Ulf; Siebner, Hartwig R

    2015-01-01

    in human cortex well beyond the time of stimulation. These aftereffects have been termed long-term potentiation (LTP)-like and long-term depression (LTD)-like plasticity because indirect evidence supported the notion that synaptic strengthening or weakening similar to LTP/D at the cellular level underlies......Non-invasive brain stimulation (NIBS) protocols such as regular repetitive transcranial magnetic stimulation (rTMS), theta-burst stimulation (TBS), paired associative stimulation (PAS) and transcranial direct current stimulation (tDCS) can change the excitability of the stimulated neuronal network...

  9. Clinical application of 16-slice spiral CT in reconstruction imaging of coronary artery for diagnosing coronary disense

    International Nuclear Information System (INIS)

    Mao Xinbo; Zhu Xinjin; Zeng Huiliang; Chen Xueguang

    2005-01-01

    Objective: An evaluation of the reconstructed imaging of coronary arteries with 16-slice spiral CT in diagnosis of coronary disease. Methods: The reconstructed images of coronary arteries obtained on a 16-slice spiral CT scanner were reviewed in 60 cases, on which the following techniques were applied: retrospective ECG-gating, Segment method with 75% R-R interval, volume rendering technique (VRT), maximum intensity projection (MIP), mulfiplanar reconstruction (MPR), curved planar reconstruction (CPR) and CT virtual endoscopy (CTVE). Results: In all 60 cases, different stages of CHD were revealed in 21 cases; none abnormality was found in 33; and images were in poor quality in 2 cases, which was available for diagnosis. There were 4 stents planted in 4 cases: soft plaque suspected in lcase, patent in 2 and occlude in 1. Conclusion: The reconstructed imaging of coronary arteries with 16-slice spiral CT is superior modality in evaluation of severe coronary stenosis, plaques, and the pantency of the intra-luminal stents, which is an efficient and non-invasive imaging in diagnosis of early-stage CHD and screening in high risk population. (authors)

  10. Non-invasive brain stimulation of motor cortex induces embodiment when integrated with virtual reality feedback.

    Science.gov (United States)

    Bassolino, M; Franza, M; Bello Ruiz, J; Pinardi, M; Schmidlin, T; Stephan, M A; Solcà, M; Serino, A; Blanke, O

    2018-04-01

    Previous evidence highlighted the multisensory-motor origin of embodiment - that is, the experience of having a body and of being in control of it - and the possibility of experimentally manipulating it. For instance, an illusory feeling of embodiment towards a fake hand can be triggered by providing synchronous visuo-tactile stimulation to the hand of participants and to a fake hand or by asking participants to move their hand and observe a fake hand moving accordingly (rubber hand illusion). Here, we tested whether it is possible to manipulate embodiment not through stimulation of the participant's hand, but by directly tapping into the brain's hand representation via non-invasive brain stimulation. To this aim, we combined transcranial magnetic stimulation (TMS), to activate the hand corticospinal representation, with virtual reality (VR), to provide matching (as contrasted to non-matching) visual feedback, mimicking involuntary hand movements evoked by TMS. We show that the illusory embodiment occurred when TMS pulses were temporally matched with VR feedback, but not when TMS was administered outside primary motor cortex, (over the vertex) or when stimulating motor cortex at a lower intensity (that did not activate peripheral muscles). Behavioural (questionnaires) and neurophysiological (motor-evoked-potentials, TMS-evoked-movements) measures further indicated that embodiment was not explained by stimulation per se, but depended on the temporal coherence between TMS-induced activation of hand corticospinal representation and the virtual bodily feedback. This reveals that non-invasive brain stimulation may replace the application of external tactile hand cues and motor components related to volition, planning and anticipation. © 2018 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  11. Microwave beamforming for non-invasive patient-specific hyperthermia treatment of pediatric brain cancer

    International Nuclear Information System (INIS)

    Burfeindt, Matthew J; Zastrow, Earl; Hagness, Susan C; Van Veen, Barry D; Medow, Joshua E

    2011-01-01

    We present a numerical study of an array-based microwave beamforming approach for non-invasive hyperthermia treatment of pediatric brain tumors. The transmit beamformer is designed to achieve localized heating-that is, to achieve constructive interference and selective absorption of the transmitted electromagnetic waves at the desired focus location in the brain while achieving destructive interference elsewhere. The design process takes into account patient-specific and target-specific propagation characteristics at 1 GHz. We evaluate the effectiveness of the beamforming approach using finite-difference time-domain simulations of two MRI-derived child head models from the Virtual Family (IT'IS Foundation). Microwave power deposition and the resulting steady-state thermal distribution are calculated for each of several randomly chosen focus locations. We also explore the robustness of the design to mismatch between the assumed and actual dielectric properties of the patient. Lastly, we demonstrate the ability of the beamformer to suppress hot spots caused by pockets of cerebrospinal fluid (CSF) in the brain. Our results show that microwave beamforming has the potential to create localized heating zones in the head models for focus locations that are not surrounded by large amounts of CSF. These promising results suggest that the technique warrants further investigation and development.

  12. Recent Advances in Non-invasive Brain Stimulation for Major Depressive Disorder

    Directory of Open Access Journals (Sweden)

    Shui Liu

    2017-11-01

    Full Text Available Non-invasive brain stimulation (NBS is a promising treatment for major depressive disorder (MDD, which is an affective processing disorder involving abnormal emotional processing. Many studies have shown that repetitive transcranial magnetic stimulation (rTMS and transcranial direct current stimulation (tDCS over the prefrontal cortex can play a regulatory role in affective processing. Although the clinical efficacy of NBS in MDD has been demonstrated clinically, the precise mechanism of action remains unclear. Therefore, this review article summarizes the current status of NBS methods, including rTMS and tDCS, in the treatment of MDD. The article explores possible correlations between depressive symptoms and affective processing, highlighting the relevant affective processing mechanisms. Our review provides a reference for the safety and efficacy of NBS methods in the clinical treatment of MDD.

  13. A potential non-invasive glioblastoma treatment: Nose-to-brain delivery of farnesylthiosalicylic acid incorporated hybrid nanoparticles.

    Science.gov (United States)

    Sekerdag, Emine; Lüle, Sevda; Bozdağ Pehlivan, Sibel; Öztürk, Naile; Kara, Aslı; Kaffashi, Abbas; Vural, Imran; Işıkay, Ilkay; Yavuz, Burҫin; Oguz, Kader Karlı; Söylemezoğlu, Figen; Gürsoy-Özdemir, Yasemin; Mut, Melike

    2017-09-10

    New drug delivery systems are highly needed in research and clinical area to effectively treat gliomas by reaching a high antineoplastic drug concentration at the target site without damaging healthy tissues. Intranasal (IN) administration, an alternative route for non-invasive drug delivery to the brain, bypasses the blood-brain-barrier (BBB) and eliminates systemic side effects. This study evaluated the antitumor efficacy of farnesylthiosalicylic acid (FTA) loaded (lipid-cationic) lipid-PEG-PLGA hybrid nanoparticles (HNPs) after IN application in rats. FTA loaded HNPs were prepared, characterized and evaluated for cytotoxicity. Rat glioma 2 (RG2) cells were implanted unilaterally into the right striatum of female Wistar rats. 10days later, glioma bearing rats received either no treatment, or 5 repeated doses of 500μM freshly prepared FTA loaded HNPs via IN or intravenous (IV) application. Pre-treatment and post-treatment tumor sizes were determined with MRI. After a treatment period of 5days, IN applied FTA loaded HNPs achieved a significant decrease of 55.7% in tumor area, equal to IV applied FTA loaded HNPs. Herewith, we showed the potential utility of IN application of FTA loaded HNPs as a non-invasive approach in glioblastoma treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives.

    Science.gov (United States)

    Bergmann, Til Ole; Karabanov, Anke; Hartwigsen, Gesa; Thielscher, Axel; Siebner, Hartwig Roman

    2016-10-15

    Non-invasive transcranial brain stimulation (NTBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial current stimulation (TCS) are important tools in human systems and cognitive neuroscience because they are able to reveal the relevance of certain brain structures or neuronal activity patterns for a given brain function. It is nowadays feasible to combine NTBS, either consecutively or concurrently, with a variety of neuroimaging and electrophysiological techniques. Here we discuss what kind of information can be gained from combined approaches, which often are technically demanding. We argue that the benefit from this combination is twofold. Firstly, neuroimaging and electrophysiology can inform subsequent NTBS, providing the required information to optimize where, when, and how to stimulate the brain. Information can be achieved both before and during the NTBS experiment, requiring consecutive and concurrent applications, respectively. Secondly, neuroimaging and electrophysiology can provide the readout for neural changes induced by NTBS. Again, using either concurrent or consecutive applications, both "online" NTBS effects immediately following the stimulation and "offline" NTBS effects outlasting plasticity-inducing NTBS protocols can be assessed. Finally, both strategies can be combined to close the loop between measuring and modulating brain activity by means of closed-loop brain state-dependent NTBS. In this paper, we will provide a conceptual framework, emphasizing principal strategies and highlighting promising future directions to exploit the benefits of combining NTBS with neuroimaging or electrophysiology. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  15. 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...

  16. Appearance and impact of post-operative intracranial clips and coils on whole-brain CT angiography and perfusion

    International Nuclear Information System (INIS)

    Roach, Cayce J.; Russell, Cheryl L.; Hanson, Eric H.; Bluett, Brent; Orrison, William W.

    2012-01-01

    Background: To evaluate the effect of vascular clips and endovascular coils placed for intracranial aneurysms and arteriovenous malformations on whole-brain computed tomography (CT) angiography and perfusion. Methods: A 320-detector row dynamic volume CT system imaged 11 patients following surgical placement of vascular clips or endovascular coils. The extent of clip and coil subtraction by automated software was evaluated using CT digital subtraction angiography and CT perfusion. Impact on CT perfusion values by retained intracranial devices was compared to age- and gender-matched controls. Results: Clip and coil subtraction on CT angiography was graded as good in 8 and moderate in 3 cases. A residual neck and additional aneurysm were noted in 1 of 11 patients. Post-procedural axial slice level CT perfusion values decreased in reliability with increasing proximity to the metallic devices secondary to beam hardening. However, the intracranial devices did not affect axial slice level CTP values of cerebral blood volume, cerebral blood flow and mean transit time outside of the level of the device. Time to peak values was globally decreased outside of the immediate vascular intervention region. Conclusions: Advances in CT technology have provided clinically useful subtraction of intracranial clips and coils. While CT perfusion values were altered in device subtraction areas and within beam hardening artifact areas; they can provide valuable postoperative information on whole-brain hemodynamics. In selected cases, the combination of CT angiography and whole-brain CT perfusion can offer an alternative to conventional angiography that is a more invasive option.

  17. "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…

  18. 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

  19. 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

  20. Electrophysiology of Hypothalamic Magnocellular Neurons In vitro: A Rhythmic Drive in Organotypic Cultures and Acute Slices.

    Science.gov (United States)

    Israel, Jean-Marc; Oliet, Stéphane H; Ciofi, Philippe

    2016-01-01

    Hypothalamic neurohormones are released in a pulsatile manner. The mechanisms of this pulsatility remain poorly understood and several hypotheses are available, depending upon the neuroendocrine system considered. Among these systems, hypothalamo-neurohypophyseal magnocellular neurons have been early-considered models, as they typically display an electrical activity consisting of bursts of action potentials that is optimal for the release of boluses of the neurohormones oxytocin and vasopressin. The cellular mechanisms underlying this bursting behavior have been studied in vitro, using either acute slices of the adult hypothalamus, or organotypic cultures of neonatal hypothalamic tissue. We have recently proposed, from experiments in organotypic cultures, that specific central pattern generator networks, upstream of magnocellular neurons, determine their bursting activity. Here, we have tested whether a similar hypothesis can be derived from in vitro experiments in acute slices of the adult hypothalamus. To this aim we have screened our electrophysiological recordings of the magnocellular neurons, previously obtained from acute slices, with an analysis of autocorrelation of action potentials to detect a rhythmic drive as we recently did for organotypic cultures. This confirmed that the bursting behavior of magnocellular neurons is governed by central pattern generator networks whose rhythmic drive, and thus probably integrity, is however less satisfactorily preserved in the acute slices from adult brains.

  1. Electrophysiology of hypothalamic magnocellular neurons in vitro: a rhythmic drive in organotypic cultures and acute slices

    Directory of Open Access Journals (Sweden)

    Jean-Marc eIsrael

    2016-03-01

    Full Text Available Hypothalamic neurohormones are released in a pulsatile manner. The mechanisms of this pulsatility remain poorly understood and several hypotheses are available, depending upon the neuroendocrine system considered. Among these systems, hypothalamo-neurohypophyseal magnocellular neurons have been early-considered models, as they typically display an electrical activity consisting of bursts of action potentials that is optimal for the release of boluses of the neurohormones oxytocin and vasopressin. The cellular mechanisms underlying this bursting behavior have been studied in vitro, using either acute slices of the adult hypothalamus, or organotypic cultures of neonatal hypothalamic tissue. We have recently proposed, from experiments in organotypic cultures, that specific central pattern generator networks, upstream of magnocellular neurons, determine their bursting activity. Here, we have tested whether a similar hypothesis can be derived from in vitro experiments in acute slices of the adult hypothalamus. To this aim we have screened our electrophysiological recordings of the magnocellular neurons, previously obtained from acute slices, with an analysis of autocorrelation of action potentials to detect a rhythmic drive as we recently did for organotypic cultures. This confirmed that the bursting behavior of magnocellular neurons is governed by central pattern generator networks whose rhythmic drive, and thus probably integrity, is however less satisfactorily preserved in the acute slices from adult brains.

  2. 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

  3. 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

  4. Non-invasive detection and quantification of brain microvascular deficits by near-infrared spectroscopy in a rat model of Vascular Cognitive Impairment

    Science.gov (United States)

    Hallacoglu, Bertan; Sassaroli, Angelo M.; Rosenberg, Irwin H.; Troen, Aron; Fantini, Sergio

    2011-02-01

    Structural abnormalities in brain microvasculature are commonly associated with Alzheimer's Disease and other dementias. However, the extent to which structural microvascular abnormalities cause functional impairments in brain circulation and thereby to cognitive impairment is unclear. Non-invasive, near-infrared spectroscopy (NIRS) methods can be used to determine the absolute hemoglobin concentration and saturation in brain tissue, from which additional parameters such as cerebral blood volume (a theoretical correlate of brain microvascular density) can be derived. Validating such NIRS parameters in animal models, and understanding their relationship to cognitive function is an important step in the ultimate application of these methods to humans. To this end we applied a non-invasive multidistance NIRS method to determine the absolute concentration and saturation of cerebral hemoglobin in rat, by separately measuring absorption and reduced scattering coefficients without relying on pre- or post-correction factors. We applied this method to study brain circulation in folate deficient rats, which express brain microvascular pathology1 and which we have shown to develop cognitive impairment.2 We found absolute brain hemoglobin concentration ([HbT]) and oxygen saturation (StO2) to be significantly lower in folate deficient rats (n=6) with respect to control rats (n=5) (for [HbT]: 73+/-10 μM vs. 95+/-14 μM for StO2: 55%+/-7% vs. 66% +/-4%), implicating microvascular pathology and diminished oxygen delivery as a mechanism of cognitive impairment. More generally, our study highlights how noninvasive, absolute NIRS measurements can provide unique insight into the pathophysiology of Vascular Cognitive Impairment. Applying this method to this and other rat models of cognitive impairment will help to validate physiologically meaningful NIRS parameters for the ultimate goal of studying cerebral microvascular disease and cognitive decline in humans.

  5. Non-invasive brain stimulation: an interventional tool for enhancing behavioral training after stroke

    Directory of Open Access Journals (Sweden)

    Maximilian Jonas Wessel

    2015-05-01

    Full Text Available Stroke is the leading cause of disability among adults. Motor deficit is the most common impairment after stroke. Especially, deficits in fine motor skills impair numerous activities of daily life. Re-acquisition of motor skills resulting in improved or more accurate motor performance is paramount to regain function, and is the basis of behavioral motor therapy after stroke. Within the past years, there has been a rapid technological and methodological development in neuroimaging leading to a significant progress in the understanding of the neural substrates that underlie motor skill acquisition and functional recovery in stroke patients. Based on this and the development of novel non-invasive brain stimulation techniques, new adjuvant interventional approaches that augment the response to behavioral training have been proposed. Transcranial direct current (tDCS, transcranial magnetic (TMS and paired associative (PAS stimulation are noninvasive brain stimulation techniques that can modulate cortical excitability, neuronal plasticity and interact with learning and memory in both healthy individuals and stroke patients. These techniques can enhance the effect of practice and facilitate the retention of tasks that mimic daily life activities. The purpose of the present review is to provide a comprehensive overview of neuroplastic phenomena in the motor system during learning of a motor skill, recovery after brain injury, and of interventional strategies to enhance the beneficial effects of customarily used neurorehabilitation after stroke.

  6. Fourier analysis of heart SPECT slices: from remodelation to function?

    International Nuclear Information System (INIS)

    Zigman, M.; Prpic, H.; Lokner, V.

    1994-01-01

    The aim of this study was to determine character of the spatial distribution of marked erythrocytes in heart chambers, lungs and great blood vessels in relation to function of the left and right heart. Investigation included total of 142 subjects, 28 of which were without subjective and clinical signs of heart disease as well as 56 after myocardial infarction (30 of anterior localization, 26 of inferior infarction), 35 with predominant left heart disease (aortic valve disease, dilatative myocardiopathy, etc.) and 23 with predominant right heart disease (atrial septal defect, mitral valve disease). Radionuclide ventriculography (RNV) at rest, and thorax SPECT were performed in all subjects with 740 MBq Tc-99m after in vivo erythrocyte labelling with pyrophosphate. Ultrasound investigation was performed on all the subjects with heart disease and 87 of them underwent invasive cardiac investigation. RNV analysis revealed scintigraphic data on left and right ventricle: global ejection fraction (GEF), end-systolic volume (ESV), end-diastolic volume (EDV), fast tilling rate (FFR), fast emptying rate (FER) as well as regional wall motion shortening. Reconstruction of 64x64x8 SPECT images resulted in 3x64 slices (transversal, coronal and sagittal slices). Fourier analysis of 20-32 reconstructed slices in all three dimensions gave amplitude image of the intensity distribution of marked erythrocytes in heart chambers lungs and great blood vessels as well as phase display of spatial localization of regional amplitude values. Results of joint ROC curves constructed for detection, localization and character of heart disease in all subjects revealed significant clinical information content of SPECT data. Evaluation of RI retention using amplitude images in 3D provides insight in regional changes of volume, particular for atrial and lung involvement. (author)

  7. 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.

  8. Targeting neural endophenotypes of eating disorders with non-invasive brain stimulation

    Directory of Open Access Journals (Sweden)

    Katharine A Dunlop

    2016-02-01

    Full Text Available The term eating disorders (ED encompasses a wide variety of disordered eating and compensatory behaviors, and so the term is associated with considerable clinical and phenotypic heterogeneity. This heterogeneity makes optimizing treatment techniques difficult. One class of treatments is non-invasive brain stimulation (NIBS. NIBS, including repetitive transcranial magnetic stimulation (rTMS and transcranial direct current stimulation (tDCS are accessible forms of neuromodulation that alter the cortical excitability of a target brain region. It is crucial for NIBS to be successful that the target is well selected for the patient population in question. Targets may best be selected by stepping back from conventional DSM-5 diagnostic criteria to identify neural substrates of more basic phenotypes, including behavior related rewards and punishment cognitive control, and social processes. These phenotypic dimensions have been recently laid out by the Research Domain Criteria (RDoC initiative. Consequently, this review is intended to identify potential dimensions as outlined by the RDoC and their underlying behavioral and neurobiological targets associated with ED as potential candidates for NIBS and review the available literature on rTMS and tDCS in ED. This review systematically reviews abnormal neural circuitry in ED within the RDoC framework, and also systematically reviews the available literature investigating NIBS as a treatment for ED.

  9. Non-Invasive Brain Stimulation to Enhance Post-Stroke Recovery.

    Science.gov (United States)

    Kubis, Nathalie

    2016-01-01

    Brain plasticity after stroke remains poorly understood. Patients may improve spontaneously within the first 3 months and then more slowly in the coming year. The first day, decreased edema and reperfusion of the ischemic penumbra may possibly account for these phenomena, but the improvement during the next weeks suggests plasticity phenomena and cortical reorganization of the brain ischemic areas and of more remote areas. Indeed, the injured ischemic motor cortex has a reduced cortical excitability at the acute phase and a suspension of the topographic representation of affected muscles, whereas the contralateral motor cortex has an increased excitability and an enlarged somatomotor representation; furthermore, contralateral cortex exerts a transcallosal interhemispheric inhibition on the ischemic cortex. This results from the imbalance of the physiological reciprocal interhemispheric inhibition of each hemisphere on the other, contributing to worsening of neurological deficit. Cortical excitability is measurable through transcranial magnetic stimulation (TMS) and prognosis has been established according to the presence of motor evoked potentials (MEP) at the acute phase of stroke, which is predictive of better recovery. Conversely, the lack of response to early stimulation is associated with a poor functional outcome. Non-invasive stimulation techniques such as repetitive TMS (rTMS) or transcranial direct current stimulation (tDCS) have the potential to modulate brain cortical excitability with long lasting effects. In the setting of cerebrovascular disease, around 1000 stroke subjects have been included in placebo-controlled trials so far, most often with an objective of promoting motor recovery of the upper limb. High frequency repetitive stimulation (>3 Hz) rTMS, aiming to increase excitability of the ischemic cortex, or low frequency repetitive stimulation (≤1 Hz), aiming to reduce excitability of the contralateral homonymous cortex, or combined therapies

  10. Non invasive brain stimulation to enhance post-stroke recovery

    Directory of Open Access Journals (Sweden)

    Nathalie Kubis

    2016-07-01

    Full Text Available Brain plasticity after stroke remains poorly understood. Patients may improve spontaneously within the first 3 months and then more slowly in the coming year. The first days, decreased edema and reperfusion of the ischemic penumbra may possibly account for these phenomena, but the improvement during the next weeks suggests plasticity phenomena and cortical reorganization of the brain ischemic areas and of more remote areas. Indeed, the injured ischemic motor cortex has a reduced cortical excitability at the acute phase and a suspension of the topographic representation of affected muscles, whereas the contralateral motor cortex has an increased excitability and an enlarged somatomotor representation; furthermore, contralateral cortex exerts a transcallosal interhemispheric inhibition on the ischemic cortex. This results from the imbalance of the physiological reciprocal interhemispheric inhibition of each hemisphere on the other, contributing to worsening of neurological deficit. Cortical excitability is measurable through transcranial magnetic stimulation (TMS and prognosis has been established according to the presence of motor evoked potentials (MEP at the acute phase of stroke, which is predictive of better recovery. Conversely, the lack of response to early stimulation is associated with a poor functional outcome. Non-invasive stimulation techniques such as repetitive TMS (rTMS or transcranial direct current stimulation (tDCS have the potential to modulate brain cortical excitability with long lasting effects. In the setting of cerebrovascular disease, around 1000 stroke subjects have been included in placebo-controlled trials so far, most often with an objective of promoting motor recovery of the upper limb. High frequency repetitive stimulation (> 3 Hz rTMS, aiming to increase excitability of the ischemic cortex, or low frequency repetitive stimulation (≤ 1 Hz, aiming to reduce excitability of the contralateral homonymous cortex, or

  11. 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

  12. Wireless brain-machine interface using EEG and EOG: brain wave classification and robot control

    Science.gov (United States)

    Oh, Sechang; Kumar, Prashanth S.; Kwon, Hyeokjun; Varadan, Vijay K.

    2012-04-01

    A brain-machine interface (BMI) links a user's brain activity directly to an external device. It enables a person to control devices using only thought. Hence, it has gained significant interest in the design of assistive devices and systems for people with disabilities. In addition, BMI has also been proposed to replace humans with robots in the performance of dangerous tasks like explosives handling/diffusing, hazardous materials handling, fire fighting etc. There are mainly two types of BMI based on the measurement method of brain activity; invasive and non-invasive. Invasive BMI can provide pristine signals but it is expensive and surgery may lead to undesirable side effects. Recent advances in non-invasive BMI have opened the possibility of generating robust control signals from noisy brain activity signals like EEG and EOG. A practical implementation of a non-invasive BMI such as robot control requires: acquisition of brain signals with a robust wearable unit, noise filtering and signal processing, identification and extraction of relevant brain wave features and finally, an algorithm to determine control signals based on the wave features. In this work, we developed a wireless brain-machine interface with a small platform and established a BMI that can be used to control the movement of a robot by using the extracted features of the EEG and EOG signals. The system records and classifies EEG as alpha, beta, delta, and theta waves. The classified brain waves are then used to define the level of attention. The acceleration and deceleration or stopping of the robot is controlled based on the attention level of the wearer. In addition, the left and right movements of eye ball control the direction of the robot.

  13. Non-invasive assessment of congenital pulmonary vein stenosis in children using cardiac-non-gated CT with 64-slice technology

    International Nuclear Information System (INIS)

    Ou, Phalla; Marini, Davide; Celermajer, David S.; Agnoletti, Gabriella; Vouhe, Pascal; Sidi, Daniel; Bonnet, Damien; Brunelle, Francis

    2009-01-01

    Background: Management of congenital pulmonary vein stenosis is a diagnostic challenge. Echocardiography may be insufficient and thus cardiac catheterization remains the reference standard in this setting. The aim of the study was to investigate the accuracy of cardiac-non-gated CT using 64-slice technology in detecting congenital pulmonary vein stenosis in children. Materials and methods: CT examinations were consecutively performed from May 2005 to December 2006 in 13 children aged 1.5-12 months (median 5 months) for suspected congenital pulmonary vein stenosis. Cardiac-non-gated CT acquisitions were performed after the peripheral injection of contrast agent. Pulmonary veins were evaluated for their pattern of connectivity from the lung to the left atrium and for the presence of stenosis. CT findings of pulmonary vein stenosis were compared with combined findings available from echocardiography, catheterization and surgery. Results: Pulmonary veins from the right lung (n = 29) and left lung (n = 26) were evaluated as separate structures (N = 55). Of the 55 structures, 32 had surgical and/or catheterization data and 45 had echocardiography for comparison. CT visualized 100% (55/55) of the investigated structures, while echocardiography visualized 82% (45/55). In the 13 subjects CT identified 10 stenotic pulmonary veins. CT confirmed the echocardiography suspicion of pulmonary vein stenosis in 100% (7/7) and established a new diagnosis in 3 other patients. CT agreed with surgery/catheterization in 100% (10/10) of the available comparisons. Conclusion: Cardiac-non-gated CT assessed the pulmonary veins more completely than echocardiography and should be considered as a viable alternative for invasive pulmonary venography for detecting pulmonary vein stenosis in children.

  14. Alteration of political belief by non- invasive brain stimulation

    Directory of Open Access Journals (Sweden)

    Caroline eChawke

    2016-01-01

    Full Text Available People generally have imperfect introspective access to the mechanisms underlying their political beliefs, yet can confidently communicate the reasoning that goes into their decision making process. An innate desire for certainty and security in ones beliefs may play an important and somewhat automatic role in motivating the maintenance or rejection of partisan support. The aim of the current study was to clarify the role of the DLPFC in the alteration of political beliefs. Recent neuroimaging studies have focused on the association between the DLPFC (a region involved in the regulation of cognitive conflict and error feedback processing and reduced affiliation with opposing political candidates. As such, this study used a method of non- invasive brain simulation (tRNS to enhance activity of the bilateral DLPFC during the incorporation of political campaign information. These findings indicate a crucial role for this region in political belief formation. However, enhanced activation of DLPFC does not necessarily result in the specific rejection of political beliefs. In contrast to the hypothesis the results appear to indicate a significant increase in conservative values regardless of participant’s initial political orientation and the political campaign advertisement they were exposed to.

  15. Alteration of Political Belief by Non-invasive Brain Stimulation

    Science.gov (United States)

    Chawke, Caroline; Kanai, Ryota

    2016-01-01

    People generally have imperfect introspective access to the mechanisms underlying their political beliefs, yet can confidently communicate the reasoning that goes into their decision making process. An innate desire for certainty and security in ones beliefs may play an important and somewhat automatic role in motivating the maintenance or rejection of partisan support. The aim of the current study was to clarify the role of the DLPFC in the alteration of political beliefs. Recent neuroimaging studies have focused on the association between the DLPFC (a region involved in the regulation of cognitive conflict and error feedback processing) and reduced affiliation with opposing political candidates. As such, this study used a method of non-invasive brain simulation (tRNS) to enhance activity of the bilateral DLPFC during the incorporation of political campaign information. These findings indicate a crucial role for this region in political belief formation. However, enhanced activation of DLPFC does not necessarily result in the specific rejection of political beliefs. In contrast to the hypothesis the results appear to indicate a significant increase in conservative values regardless of participant's initial political orientation and the political campaign advertisement they were exposed to. PMID:26834603

  16. 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.

  17. 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.

  18. Non-invasive brain stimulation enhances the effects of Melodic Intonation Therapy

    Directory of Open Access Journals (Sweden)

    Bradley W. Vines

    2011-09-01

    Full Text Available Research has suggested that a fronto-temporal network in the right hemisphere may be responsible for mediating Melodic Intonation Therapy’s positive effects on speech recovery. We investigated the potential for a non-invasive brain stimulation technique, transcranial direct current stimulation (tDCS, to augment the benefits of MIT in patients with non-fluent aphasia by modulating neural activity in the brain during treatment with MIT. The polarity of the current applied to the scalp determines the effects of tDCS on the underlying tissue: anodal tDCS increases excitability, whereas cathodal tDCS decreases excitability. We applied anodal tDCS to the posterior inferior frontal gyrus (IFG of the right hemisphere, an area that has been shown to both contribute to singing through the mapping of sounds to ariculatory actions and serve as a key region in the process of recovery from aphasia, particularly in patients with large left hemispheric lesions. The stimulation was applied while patients were treated with MIT by a trained therapist. Six patients with moderate to severe non-fluent aphasia underwent three consecutive days of anodal-tDCS+MIT, and an equivalent series of sham-tDCS+MIT. The two treatment series were separated by one week, and the order in which the treatments were administered was randomized. Compared to the effects of sham-tDCS+MIT, anodal-tDCS+MIT led to significant improvements in fluency of speech. These results support the hypothesis that, as the brain seeks to reorganize and compensate for damage to left-hemisphere language centers, combining anodal-tDCS with MIT may further recovery from post-stroke aphasia by enhancing activity in a right-hemisphere sensorimotor network for articulation.

  19. Non-invasive brain stimulation to promote motor and functional recovery following spinal cord injury

    Directory of Open Access Journals (Sweden)

    Aysegul Gunduz

    2017-01-01

    Full Text Available We conducted a systematic review of studies using non-invasive brain stimulation (NIBS: repetitive transcranial magnetic stimulation (rTMS and transcranial direct current stimulation (tDCS as a research and clinical tool aimed at improving motor and functional recovery or spasticity in patients following spinal cord injury (SCI under the assumption that if the residual corticospinal circuits could be stimulated appropriately, the changes might be accompanied by functional recovery or an improvement in spasticity. This review summarizes the literature on the changes induced by NIBS in the motor and functional recovery and spasticity control of the upper and lower extremities following SCI.

  20. 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.

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

    Science.gov (United States)

    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.

  2. 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.

  3. Induction of neuroplasticity and recovery in post-stroke aphasia by non-invasive brain stimulation.

    Science.gov (United States)

    Shah, Priyanka P; Szaflarski, Jerzy P; Allendorfer, Jane; Hamilton, Roy H

    2013-12-24

    Stroke victims tend to prioritize speaking, writing, and walking as the three most important rehabilitation goals. Of note is that two of these goals involve communication. This underscores the significance of developing successful approaches to aphasia treatment for the several hundred thousand new aphasia patients each year and over 1 million stroke survivors with chronic aphasia in the U.S. alone. After several years of growth as a research tool, non-invasive brain stimulation (NBS) is gradually entering the arena of clinical aphasiology. In this review, we first examine the current state of knowledge of post-stroke language recovery including the contributions from the dominant and non-dominant hemispheres. Next, we briefly discuss the methods and the physiologic basis of the use of inhibitory and excitatory repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) as research tools in patients who experience post-stroke aphasia. Finally, we provide a critical review of the most influential evidence behind the potential use of these two brain stimulation methods as clinical rehabilitative tools.

  4. 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.

  5. 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

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  8. Trypanosoma brucei Invasion and T-Cell Infiltration of the Brain Parenchyma in Experimental Sleeping Sickness: Timing and Correlation with Functional Changes.

    Directory of Open Access Journals (Sweden)

    Claudia Laperchia

    2016-12-01

    Full Text Available The timing of Trypanosoma brucei entry into the brain parenchyma to initiate the second, meningoencephalitic stage of human African trypanosomiasis or sleeping sickness is currently debated and even parasite invasion of the neuropil has been recently questioned. Furthermore, the relationship between neurological features and disease stage are unclear, despite the important diagnostic and therapeutic implications.Using a rat model of chronic Trypanosoma brucei brucei infection we determined the timing of parasite and T-cell neuropil infiltration and its correlation with functional changes. Parasite DNA was detected using trypanosome-specific PCR. Body weight and sleep structure alterations represented by sleep-onset rapid eye movement (SOREM periods, reported in human and experimental African trypanosomiasis, were monitored. The presence of parasites, as well as CD4+ and CD8+ T-cells in the neuropil was assessed over time in the brain of the same animals by immunocytochemistry and quantitative analyses.Trypanosome DNA was present in the brain at day 6 post-infection and increased more than 15-fold by day 21. Parasites and T-cells were observed in the parenchyma from day 9 onwards. Parasites traversing blood vessel walls were observed in the hypothalamus and other brain regions. Body weight gain was reduced from day 7 onwards. SOREM episodes started in most cases early after infection, with an increase in number and duration after parasite neuroinvasion.These findings demonstrate invasion of the neuropil over time, after an initial interval, by parasites and lymphocytes crossing the blood-brain barrier, and show that neurological features can precede this event. The data thus challenge the current clinical and cerebrospinal fluid criteria of disease staging.

  9. Trypanosoma brucei Invasion and T-Cell Infiltration of the Brain Parenchyma in Experimental Sleeping Sickness: Timing and Correlation with Functional Changes.

    Science.gov (United States)

    Laperchia, Claudia; Palomba, Maria; Seke Etet, Paul F; Rodgers, Jean; Bradley, Barbara; Montague, Paul; Grassi-Zucconi, Gigliola; Kennedy, Peter G E; Bentivoglio, Marina

    2016-12-01

    The timing of Trypanosoma brucei entry into the brain parenchyma to initiate the second, meningoencephalitic stage of human African trypanosomiasis or sleeping sickness is currently debated and even parasite invasion of the neuropil has been recently questioned. Furthermore, the relationship between neurological features and disease stage are unclear, despite the important diagnostic and therapeutic implications. Using a rat model of chronic Trypanosoma brucei brucei infection we determined the timing of parasite and T-cell neuropil infiltration and its correlation with functional changes. Parasite DNA was detected using trypanosome-specific PCR. Body weight and sleep structure alterations represented by sleep-onset rapid eye movement (SOREM) periods, reported in human and experimental African trypanosomiasis, were monitored. The presence of parasites, as well as CD4+ and CD8+ T-cells in the neuropil was assessed over time in the brain of the same animals by immunocytochemistry and quantitative analyses. Trypanosome DNA was present in the brain at day 6 post-infection and increased more than 15-fold by day 21. Parasites and T-cells were observed in the parenchyma from day 9 onwards. Parasites traversing blood vessel walls were observed in the hypothalamus and other brain regions. Body weight gain was reduced from day 7 onwards. SOREM episodes started in most cases early after infection, with an increase in number and duration after parasite neuroinvasion. These findings demonstrate invasion of the neuropil over time, after an initial interval, by parasites and lymphocytes crossing the blood-brain barrier, and show that neurological features can precede this event. The data thus challenge the current clinical and cerebrospinal fluid criteria of disease staging.

  10. Intraoperative detection of glioma invasion beyond MRI enhancement with Raman spectroscopy in humans

    Science.gov (United States)

    Jermyn, Michael; Mok, Kelvin; Mercier, Jeanne; Desroches, Joannie; Pichette, Julien; Saint-Arnaud, Karl; Guiot, Marie-Christine; Petrecca, Kevin; Leblond, Frédéric

    2015-03-01

    Cancer tissue is frequently impossible to distinguish from normal brain during surgery. Gliomas are a class of brain cancer which invade into the normal brain. If left unresected, these invasive cancer cells are the source of glioma recurrence. Moreover, these invasion areas do not show up on standard-of-care pre-operative Magnetic Resonance Imaging (MRI). This inability to fully visualize invasive brain cancers results in subtotal surgical resections, negatively impacting patient survival. To address this issue, we have demonstrated the efficacy of single-point in vivo Raman spectroscopy using a contact hand-held fiber optic probe for rapid detection of cancer invasion in 8 patients with low and high grade gliomas. Using a supervised machine learning algorithm to analyze the Raman spectra obtained in vivo, we were able to distinguish normal brain from the presence of cancer cells with sensitivity and specificity greater than 90%. Moreover, by correlating these results with pre-operative MRI we demonstrate the ability to detect low density cancer invasion up to 1.5cm beyond the cancer extent visible using MRI. This represents the potential for significant improvements in progression-free and overall patient survival, by identifying previously undetectable residual cancer cell populations and preventing the resection of normal brain tissue. While the importance of maximizing the volume of tumor resection is important for all grades of gliomas, the impact for low grade gliomas can be dramatic because surgery can even be curative. This convenient technology can rapidly classify cancer invasion in real-time, making it ideal for intraoperative use in brain tumor resection.

  11. Brain injury impairs working memory and prefrontal circuit function

    Directory of Open Access Journals (Sweden)

    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.

  12. Current status and future of non-invasive studies of human brain functions

    International Nuclear Information System (INIS)

    Shibasaki, Hiroshi

    2008-01-01

    Currently available non-invasive studies are divided into two groups: electrophysiological studies and functional neuroimaging based on the hemodynamic principle. The former includes electroencephalography (EEG), magnetoencephalography (MEG) and transcranial magnetic stimulation, and the latter includes functional MRI, positron emission tomography (PET), single photon emission computed tomography (SPECT) and near-infrared spectroscopy. The hemodynamic response has been shown to be correlated with neuronal electrical activity, especially with synaptic activity rather than spiking activity, within a certain range. Since each technique has advantage and disadvantage, it is important to apply the most appropriate technique to solve each specific question. The combined use of more than one techniques of different principles, if possible, provides data of higher spatial and temporal resolution. Functional connectivity among different brain areas can be studied by using some of these techniques either alone or in combination. (author)

  13. 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.

  14. Co-registration of pre-operative CT with ex vivo surgically excised ground glass nodules to define spatial extent of invasive adenocarcinoma on in vivo imaging: a proof-of-concept study

    Energy Technology Data Exchange (ETDEWEB)

    Rusu, Mirabela [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); GE Global Research, Niskayuna, NY (United States); Rajiah, Prabhakar [UT Southwestern Medical Center, Dallas, TX (United States); Cleveland Medical Center and Case Western Reserve University, University Hospitals, Cleveland, OH (United States); Gilkeson, Robert; Yang, Michael; Donatelli, Christopher; Linden, Philip [Cleveland Medical Center and Case Western Reserve University, University Hospitals, Cleveland, OH (United States); Thawani, Rajat; Madabhushi, Anant [Case Western Reserve University, Department of Biomedical Engineering, Cleveland, OH (United States); Jacono, Frank J. [Cleveland Medical Center and Case Western Reserve University, University Hospitals, Cleveland, OH (United States); Louis Stokes Cleveland VA Medical Center, Cleveland, OH (United States)

    2017-10-15

    To develop an approach for radiology-pathology fusion of ex vivo histology of surgically excised pulmonary nodules with pre-operative CT, to radiologically map spatial extent of the invasive adenocarcinomatous component of the nodule. Six subjects (age: 75 ± 11 years) with pre-operative CT and surgically excised ground-glass nodules (size: 22.5 ± 5.1 mm) with a significant invasive adenocarcinomatous component (>5 mm) were included. The pathologist outlined disease extent on digitized histology specimens; two radiologists and a pulmonary critical care physician delineated the entire nodule on CT (in-plane resolution: <0.8 mm, inter-slice distance: 1-5 mm). We introduced a novel reconstruction approach to localize histology slices in 3D relative to each other while using CT scan as spatial constraint. This enabled the spatial mapping of the extent of tumour invasion from histology onto CT. Good overlap of the 3D reconstructed histology and the nodule outlined on CT was observed (65.9 ± 5.2%). Reduction in 3D misalignment of corresponding anatomical landmarks on histology and CT was observed (1.97 ± 0.42 mm). Moreover, the CT attenuation (HU) distributions were different when comparing invasive and in situ regions. This proof-of-concept study suggests that our fusion method can enable the spatial mapping of the invasive adenocarcinomatous component from 2D histology slices onto in vivo CT. (orig.)

  15. Co-registration of pre-operative CT with ex vivo surgically excised ground glass nodules to define spatial extent of invasive adenocarcinoma on in vivo imaging: a proof-of-concept study

    International Nuclear Information System (INIS)

    Rusu, Mirabela; Rajiah, Prabhakar; Gilkeson, Robert; Yang, Michael; Donatelli, Christopher; Linden, Philip; Thawani, Rajat; Madabhushi, Anant; Jacono, Frank J.

    2017-01-01

    To develop an approach for radiology-pathology fusion of ex vivo histology of surgically excised pulmonary nodules with pre-operative CT, to radiologically map spatial extent of the invasive adenocarcinomatous component of the nodule. Six subjects (age: 75 ± 11 years) with pre-operative CT and surgically excised ground-glass nodules (size: 22.5 ± 5.1 mm) with a significant invasive adenocarcinomatous component (>5 mm) were included. The pathologist outlined disease extent on digitized histology specimens; two radiologists and a pulmonary critical care physician delineated the entire nodule on CT (in-plane resolution: <0.8 mm, inter-slice distance: 1-5 mm). We introduced a novel reconstruction approach to localize histology slices in 3D relative to each other while using CT scan as spatial constraint. This enabled the spatial mapping of the extent of tumour invasion from histology onto CT. Good overlap of the 3D reconstructed histology and the nodule outlined on CT was observed (65.9 ± 5.2%). Reduction in 3D misalignment of corresponding anatomical landmarks on histology and CT was observed (1.97 ± 0.42 mm). Moreover, the CT attenuation (HU) distributions were different when comparing invasive and in situ regions. This proof-of-concept study suggests that our fusion method can enable the spatial mapping of the invasive adenocarcinomatous component from 2D histology slices onto in vivo CT. (orig.)

  16. Invasive brain-machine interfaces: a survey of paralyzed patients’ attitudes, knowledge and methods of information retrieval

    Science.gov (United States)

    Lahr, Jacob; Schwartz, Christina; Heimbach, Bernhard; Aertsen, Ad; Rickert, Jörn; Ball, Tonio

    2015-08-01

    Objective. Brain-machine interfaces (BMI) are an emerging therapeutic option that can allow paralyzed patients to gain control over assistive technology devices (ATDs). BMI approaches can be broadly classified into invasive (based on intracranially implanted electrodes) and noninvasive (based on skin electrodes or extracorporeal sensors). Invasive BMIs have a favorable signal-to-noise ratio, and thus allow for the extraction of more information than noninvasive BMIs, but they are also associated with the risks related to neurosurgical device implantation. Current noninvasive BMI approaches are typically concerned, among other issues, with long setup times and/or intensive training. Recent studies have investigated the attitudes of paralyzed patients eligible for BMIs, particularly patients affected by amyotrophic lateral sclerosis (ALS). These studies indicate that paralyzed patients are indeed interested in BMIs. Little is known, however, about the degree of knowledge among paralyzed patients concerning BMI approaches or about how patients retrieve information on ATDs. Furthermore, it is not yet clear if paralyzed patients would accept intracranial implantation of BMI electrodes with the premise of decoding improvements, and what the attitudes of a broader range of patients with diseases such as stroke or spinal cord injury are towards this new kind of treatment. Approach. Using a questionnaire, we surveyed 131 paralyzed patients for their opinions on invasive BMIs and their attitude toward invasive BMI treatment options. Main results. The majority of the patients knew about and had a positive attitude toward invasive BMI approaches. The group of ALS patients was especially open to the concept of BMIs. The acceptance of invasive BMI technology depended on the improvements expected from the technology. Furthermore, the survey revealed that for paralyzed patients, the Internet is an important source of information on ATDs. Significance. Websites tailored to

  17. 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.

  18. 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.

  19. Noninvasive detection of coronary abnormalities in pediatric patients with Kawassaki disease using multi-slice spiral CT

    International Nuclear Information System (INIS)

    Hou Yang; Guo Wenli; Yue Yong; Chen Liying; Guo Qiyong; Yu Xianyi; Wang Hong

    2006-01-01

    Objective: To evaluate the feasibility and value of detecting coronary artery lesions in Kawasaki disease using multi-slice computed tomography (MSCT). Methods: Thirty-four pediatric patients underwent 16-slice or 64-slice CT coronary, angiography. 18 patients were also examined with 2 dimension echocardiography (2DE). In all cases, visibility of coronary artery segment was recorded. The diameter of the LCA, RCA were measured in MSCTA and compared with 2DE. Correlation coefficient of dimension and coincidence rate of two methods were calculated. Results: Coronary artery lesions were found in 14 patients (22 branches) of the 34 cases with KD on MSCT. Six cases were dialated, 3 cases were dialated with aneurysms, 2 cases had aneurysms without dialation. Coronary artery stenosis in 1 eases, calcification in 2 cases. Three cases had multiple aneurysms with the presence of alternate stenosis that made the artery a bead-like appearance. CC of LM and RCA were 0.85, 0.91, respectively (P>0.05). Three coronary artery aneurysm in the distal RCA was missed by 2DE. MSCT could not detect slight or moderate mitral regurgitation in 2 patients and artery wall thickening in 5 patients. Conclusion: MSCT would be an effective complementary or alternative method for CDEC to evaluate coronary artery lesions non-invasively in pediatric patients with Kawasaki disease. (authors)

  20. 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).

  1. 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.

  2. Non-invasive optical monitoring of the newborn piglet brain using continuous-wave and frequency-domain spectroscopy

    International Nuclear Information System (INIS)

    Fantini, S.; Franceschini, M.A.; Gratton, E.; Hueber, D.; Rosenfeld, W.; Maulik, D.; Stubblefield, P.G.; Stankovic, M.R.

    1999-01-01

    We have used continuous-wave (CW) and frequency-domain spectroscopy to investigate the optical properties of the newborn piglet brain in vivo and non-invasively. Three anaesthetized, intubated, ventilated and instrumented newborn piglets were placed into a stereotaxic instrument for optimal experimental stability, reproducible probe-to-scalp optical contact and 3D adjustment of the optical probe. By measuring the absolute values of the brain absorption and reduced scattering coefficients at two wavelengths (758 and 830 nm), frequency-domain spectroscopy provided absolute readings (in contrast to the relative readings of CW spectroscopy) of cerebral haemoglobin concentration and saturation during experimentally induced perturbations in cerebral haemodynamics and oxygenation. Such perturbations included a modulation of the inspired oxygen concentration, transient brain asphyxia, carotid artery occlusion and terminal brain asphyxia. The baseline cerebral haemoglobin saturation and concentration, measured with frequency-domain spectroscopy, were about 60% and 42 μM respectively. The cerebral saturation values ranged from a minimum of 17% (during transient brain asphyxia) to a maximum of 80% (during recovery from transient brain asphyxia). To analyse the CW optical data, we have (a) derived a mathematical relationship between the cerebral optical properties and the differential pathlength factor and (b) introduced a method based on the spatial dependence of the detected intensity (dc slope method). The analysis of the cerebral optical signals associated with the arterial pulse and with respiration demonstrates that motion artefacts can significantly affect the intensity recorded from a single optode pair. Motion artefacts can be strongly reduced by combining data from multiple optodes to provide relative readings in the dc slope method. We also report significant biphasic changes (initial decrease and successive increase) in the reduced scattering coefficient measured

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  4. 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

  5. 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.

  6. Multi-slice spiral CT detects spread of small laryngeal tumors

    International Nuclear Information System (INIS)

    Bruening, R.; Schoepf, U.; Becker, C.; Reiser, M.; Hong, C.; Sturm, C.; Wollenberg, B.

    1999-01-01

    The purpose of the study was to preoperatively investigate small laryngeal carcinomas using multi-slice spiral CT (MSCT) and subsequent multiplanar reconstructions (MPR) and to compare the results to the detailed spread found a surgery and histology. Nine patients with small (T1, T2) laryngeal cancer were investigated on a MSCT scanner (Siemens plus 4 Volume Zoom, Siemens). A 4x1 mm collimation, 120 kV, 200 mAs and a 0.5 seconds rotation time were used, allowing a coverage of the entire larynx in approximately 10 seconds within a single breathhold. Multiplanar reconstruction's (MPR) in sagittal and coronal plane were reconstructed in all patients and rated in consensus reading. In 8 of nine patients, the glottic spread was detected by MSCT, in one case of a supraglottic tumor a glottic invasion was excluded. The infiltration of the anterior commissure, the infiltration into the subglottic space and the extension into the hypo-pharynx was correctly assessed in all patients. MSCT was not able to predict infiltration of the arythnoids in two patients. The use of multi-slice CT for the preoperative assessment of small laryngeal tumors shows great promise. The detection or exclusion of subtle spread of these tumors into the supra- or subglottic space and along the glottic level was possible with high accuracy. As the examination time is short, artifacts are rare and multiplanar reconstructions gain in clinical importance. (orig.) [de

  7. 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

  8. 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...

  9. A non-invasive method of quantifying pancreatic volume in mice using micro-MRI.

    Directory of Open Access Journals (Sweden)

    Jose L Paredes

    Full Text Available In experimental models of pancreatic growth and recovery, changes in pancreatic size are assessed by euthanizing a large cohort of animals at varying time points and measuring organ mass. However, to ascertain this information in clinical practice, patients with pancreatic disorders routinely undergo non-invasive cross-sectional imaging of the pancreas using magnetic resonance imaging (MRI or computed tomography (CT. The aim of the current study was to develop a thin-sliced, optimized sequence protocol using a high field MRI to accurately calculate pancreatic volumes in the most common experimental animal, the mouse. Using a 7 Telsa Bruker micro-MRI system, we performed abdominal imaging in whole-fixed mice in three standard planes: axial, sagittal, and coronal. The contour of the pancreas was traced using Vitrea software and then transformed into a 3-dimensional (3D reconstruction, from which volumetric measurements were calculated. Images were optimized using heart perfusion-fixation, T1 sequence analysis, and 0.2 to 0.4 mm thick slices. As proof of principle, increases in pancreatic volume among mice of different ages correlated tightly with increasing body weight. In summary, this is the first study to measure pancreatic volumes in mice, using a high field 7 Tesla micro-MRI and a thin-sliced, optimized sequence protocol. We anticipate that micro-MRI will improve the ability to non-invasively quantify changes in pancreatic size and will dramatically reduce the number of animals required to serially assess pancreatic growth and recovery.

  10. 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.

  11. 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.

  12. 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.)

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

    Science.gov (United States)

    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.

  14. 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.

  15. 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

  16. 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.

  17. 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)

  18. Actinic keratosis in the en-face and slice imaging mode of high-definition optical coherence tomography and comparison with histology.

    Science.gov (United States)

    Maier, T; Braun-Falco, M; Laubender, R P; Ruzicka, T; Berking, C

    2013-01-01

    Optical coherence tomography (OCT) allows real-time, in vivo examination of nonmelanoma skin cancer. An innovative high-definition (HD)-OCT with a horizontal (en-face) and vertical (slice) imaging mode offers additional information in the diagnosis of actinic keratosis (AK) and may potentially replace invasive diagnostic biopsies.  To define the characteristic morphological features of AK by using HD-OCT in the two imaging modes compared with histopathology as gold standard.  In total, 20 AKs were examined by HD-OCT in the en-face and slice imaging modes and characteristic features were described and evaluated in comparison with the histopathological findings. Furthermore, the HD-OCT images of a subgroup of AKs were compared with those of the clinically normal adjacent skin.  The preoperative in vivo diagnostics showed the following features in the en-face imaging mode of HD-OCT: disruption of stratum corneum, architectural disarray, cellular/nuclear polymorphism in the stratum granulosum/stratum spinosum, and bright irregular bundles in the superficial dermis. In the vertical slice imaging mode the following characteristics were found: irregular entrance signal, destruction of layering, white streaks and dots, and grey areas. In contrast, the clinically healthy adjacent skin showed mainly a regular epidermal 'honeycomb' pattern in the en-face mode and distinct layering of the skin in the slice mode.  HD-OCT with both the en-face and slice imaging modes offers additional information in the diagnosis of AK compared with conventional OCT and might enhance the possibility of the noninvasive diagnosis of AK prior to treatment procedures and possibly in the monitoring of noninvasive treatment strategies. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.

  19. 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

  20. 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 ...

  1. Invasive Glioblastoma Cells Acquire Stemness and Increased Akt Activation

    Directory of Open Access Journals (Sweden)

    Jennifer R. Molina

    2010-06-01

    Full Text Available Glioblastoma multiforme (GBM is the most frequent and most aggressive brain tumor in adults. The dismal prognosis is due to postsurgery recurrences arising from escaped invasive tumor cells. The signaling pathways activated in invasive cells are under investigation, and models are currently designed in search for therapeutic targets. We developed here an in vivo model of human invasive GBM in mouse brain from a GBM cell line with moderate tumorigenicity that allowed simultaneous primary tumor growth and dispersal of tumor cells in the brain parenchyma. This strategy allowed for the first time the isolation and characterization of matched sets of tumor mass (Core and invasive (Inv cells. Both cell populations, but more markedly Inv cells, acquired stem cell markers, neurosphere renewal ability, and resistance to rapamycin-induced apoptosis relative to parental cells. The comparative phenotypic analysis between Inv and Core cells showed significantly increased tumorigenicity in vivo and increased invasion with decreased proliferation in vitro for Inv cells. Examination of a large array of signaling pathways revealed extracellular signal-regulated kinase (Erk down-modulation and Akt activation in Inv cells and an opposite profile in Core cells. Akt activation correlated with the increased tumorigenicity, stemness, and invasiveness, whereas Erk activation correlated with the proliferation of the cells. These results underscore complementary roles of the Erk and Akt pathways for GBM proliferation and dispersal and raise important implications for a concurrent inhibitory therapy.

  2. Early invasion of brain parenchyma by African trypanosomes.

    Directory of Open Access Journals (Sweden)

    Ute Frevert

    Full Text Available Human African trypanosomiasis or sleeping sickness is a vector-borne parasitic disease that has a major impact on human health and welfare in sub-Saharan countries. Based mostly on data from animal models, it is currently thought that trypanosome entry into the brain occurs by initial infection of the choroid plexus and the circumventricular organs followed days to weeks later by entry into the brain parenchyma. However, Trypanosoma brucei bloodstream forms rapidly cross human brain microvascular endothelial cells in vitro and appear to be able to enter the murine brain without inflicting cerebral injury. Using a murine model and intravital brain imaging, we show that bloodstream forms of T. b. brucei and T. b. rhodesiense enter the brain parenchyma within hours, before a significant level of microvascular inflammation is detectable. Extravascular bloodstream forms were viable as indicated by motility and cell division, and remained detectable for at least 3 days post infection suggesting the potential for parasite survival in the brain parenchyma. Vascular inflammation, as reflected by leukocyte recruitment and emigration from cortical microvessels, became apparent only with increasing parasitemia at later stages of the infection, but was not associated with neurological signs. Extravascular trypanosomes were predominantly associated with postcapillary venules suggesting that early brain infection occurs by parasite passage across the neuroimmunological blood brain barrier. Thus, trypanosomes can invade the murine brain parenchyma during the early stages of the disease before meningoencephalitis is fully established. Whether individual trypanosomes can act alone or require the interaction from a quorum of parasites remains to be shown. The significance of these findings for disease development is now testable.

  3. 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.

  4. Non-Invasive Brain Stimulation: A New Strategy in Mild Cognitive Impairment?

    Science.gov (United States)

    Birba, Agustina; Ibáñez, Agustín; Sedeño, Lucas; Ferrari, Jesica; García, Adolfo M.; Zimerman, Máximo

    2017-01-01

    Non-invasive brain stimulation (NIBS) techniques can significantly modulate cognitive functions in healthy subjects and patients with neuropsychiatric disorders. Recently, they have been applied in patients with mild cognitive impairment (MCI) and subjective cognitive impairment (SCI) to prevent or delay the development of Alzheimer’s disease (AD). Here we review this emerging empirical corpus and discuss therapeutic effects of NIBS on several target functions (e.g., memory for face-name associations and non-verbal recognition, attention, psychomotor speed, everyday memory). Available studies have yielded mixed results, possibly due to differences among their tasks, designs, and samples, let alone the latter’s small sizes. Thus, the impact of NIBS on cognitive performance in MCI and SCI remains to be determined. To foster progress in this direction, we outline methodological approaches that could improve the efficacy and specificity of NIBS in both conditions. Furthermore, we discuss the need for multicenter studies, accurate diagnosis, and longitudinal approaches combining NIBS with specific training regimes. These tenets could cement biomedical developments supporting new treatments for MCI and preventive therapies for AD. PMID:28243198

  5. 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.

  6. 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)

  7. [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)

  8. 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.)

  9. 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.

  10. 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

  11. Diagnostic performance of 64-slice multidetector coronary computed tomographic angiography in women.

    Science.gov (United States)

    Jug, Borut; Gupta, Mohit; Papazian, Jenny; Li, Dong; Tsang, Janet; Bhatia, Harpreet; Karlsberg, Ronald; Budoff, Matthew

    2012-12-01

    Diagnostic approach to chest pain in women is challenging, but still under-investigated. The purpose of this study was to assess the diagnostic performance of 64-slice multidetector coronary computed tomographic angiography (CCTA) in women with chest pain. We included 606 patients--255 women and 351 men (mean age 61 ± 12 years for both)--who had been referred for a CCTA and an invasive coronary angiography (diagnostic standard) because of chest pain, either as part of clinical work-up in two urban medical centers or as part of the multicenter ACCURACY trial. On a patient-based model, the sensitivity, specificity, and positive predictive value (PPV) and negative predictive value to detect ≥50% and ≥70% stenosis were 98%, 84%, 87%, and 97% and 96%, 83%, 77%, and 97%, respectively, for women and 97%, 83%, 89%, and 95% and 94%, 91%, 90%, and 94%, respectively, for men. There were no statistically significant differences between men and women in diagnostic performance measures except for the PPV of detecting a ≥70% stenosis (P = .007). In women with chest pain, 64-slice multidetector CCTA is at least as sensitive and specific as in men. Our findings suggest that CCTA is a promising diagnostic tool for timely detection and/or exclusion of CAD in symptomatic intermediate-risk female populations.

  12. 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)

  13. Minimally Invasive Technique for PMMA Augmentation of Fenestrated Screws

    Directory of Open Access Journals (Sweden)

    Jan-Helge Klingler

    2015-01-01

    Full Text Available Purpose. To describe the minimally invasive technique for cement augmentation of cannulated and fenestrated screws using an injection cannula as well as to report its safety and efficacy. Methods. A total of 157 cannulated and fenestrated pedicle screws had been cement-augmented during minimally invasive posterior screw-rod spondylodesis in 35 patients from January to December 2012. Retrospective evaluation of cement extravasation and screw loosening was carried out in postoperative plain radiographs and thin-sliced triplanar computed tomography scans. Results. Twenty-seven, largely prevertebral cement extravasations were detected in 157 screws (17.2%. None of the cement extravasations was causing a clinical sequela like a new neurological deficit. One screw loosening was noted (0.6% after a mean follow-up of 12.8 months. We observed no cementation-associated complication like pulmonary embolism or hemodynamic insufficiency. Conclusions. The presented minimally invasive cement augmentation technique using an injection cannula facilitates convenient and safe cement delivery through polyaxial cannulated and fenestrated screws during minimally invasive screw-rod spondylodesis. Nevertheless, the optimal injection technique and design of fenestrated screws have yet to be identified. This trial is registered with German Clinical Trials DRKS00006726.

  14. 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

  15. 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

  16. 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.

    1992-03-01

    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.

  17. 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.

  18. Non-invasive brain stimulation: an interventional tool for enhancing behavioral training after stroke.

    Science.gov (United States)

    Wessel, Maximilian J; Zimerman, Máximo; Hummel, Friedhelm C

    2015-01-01

    Stroke is the leading cause of disability among adults. Motor deficit is the most common impairment after stroke. Especially, deficits in fine motor skills impair numerous activities of daily life. Re-acquisition of motor skills resulting in improved or more accurate motor performance is paramount to regain function, and is the basis of behavioral motor therapy after stroke. Within the past years, there has been a rapid technological and methodological development in neuroimaging leading to a significant progress in the understanding of the neural substrates that underlie motor skill acquisition and functional recovery in stroke patients. Based on this and the development of novel non-invasive brain stimulation (NIBS) techniques, new adjuvant interventional approaches that augment the response to behavioral training have been proposed. Transcranial direct current, transcranial magnetic, and paired associative (PAS) stimulation are NIBS techniques that can modulate cortical excitability, neuronal plasticity and interact with learning and memory in both healthy individuals and stroke patients. These techniques can enhance the effect of practice and facilitate the retention of tasks that mimic daily life activities. The purpose of the present review is to provide a comprehensive overview of neuroplastic phenomena in the motor system during learning of a motor skill, recovery after brain injury, and of interventional strategies to enhance the beneficial effects of customarily used neurorehabilitation after stroke.

  19. Sensitivity analysis of brain morphometry based on MRI-derived surface models

    Science.gov (United States)

    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

  20. Brain size and urbanization in birds

    Institute of Scientific and Technical Information of China (English)

    Anders; Pape; M?ller; Johannes; Erritz?e

    2015-01-01

    Background: Brain size may affect the probability of invasion of urban habitats if a relatively larger brain entails superior ability to adapt to novel environments. However, once urbanized urban environments may provide poor quality food that has negative consequences for normal brain development resulting in an excess of individuals with small brains.Methods: Here we analyze the independent effects of mean, standard deviation and skewness in brain mass for invasion of urban habitats by 108 species of birds using phylogenetic multiple regression analyses weighted by sample size.Results: There was no significant difference in mean brain mass between urbanized and non-urbanized species or between urban and rural populations of the same species, and mean brain mass was not significantly correlated with time since urbanization. Bird species that became urbanized had a greater standard deviation in brain mass than non-urbanized species, and the standard deviation in brain mass increased with time since urbanization. Brain mass was significantly left skewed in species that remained rural, while there was no significant skew in urbanized species. The degree of left skew was greater in urban than in rural populations of the same species, and successfully urbanized species decreased the degree of left skew with time since urbanization. This is consistent with the hypothesis that sub-optimal brain development was more common in rural habitats resulting in disproportionately many individuals with very smal brains.Conclusions: These findings do not support the hypothesis that large brains promote urbanization, but suggest that skewness has played a role in the initial invasion of urban habitats, and that variance and skew in brain mass have increased as species have become urbanized.

  1. Brain size and urbanization in birds

    Institute of Scientific and Technical Information of China (English)

    Anders Pape Mller; Johannes Erritze

    2015-01-01

    Background:Brain size may affect the probability of invasion of urban habitats if a relatively larger brain entails superior ability to adapt to novel environments. However, once urbanized urban environments may provide poor quality food that has negative consequences for normal brain development resulting in an excess of individuals with small brains. Methods:Here we analyze the independent effects of mean, standard deviation and skewness in brain mass for invasion of urban habitats by 108 species of birds using phylogenetic multiple regression analyses weighted by sample size. Results:There was no significant difference in mean brain mass between urbanized and non-urbanized species or between urban and rural populations of the same species, and mean brain mass was not significantly correlated with time since urbanization. Bird species that became urbanized had a greater standard deviation in brain mass than non-urbanized species, and the standard deviation in brain mass increased with time since urbanization. Brain mass was significantly left skewed in species that remained rural, while there was no significant skew in urbanized species. The degree of left skew was greater in urban than in rural populations of the same species, and successfully urbanized species decreased the degree of left skew with time since urbanization. This is consistent with the hypothesis that sub-optimal brain development was more common in rural habitats resulting in disproportionately many individuals with very smal brains. Conclusions:These findings do not support the hypothesis that large brains promote urbanization, but suggest that skewness has played a role in the initial invasion of urban habitats, and that variance and skew in brain mass have increased as species have become urbanized.

  2. Precision analysis of a multi-slice ultrasound sensor for non-invasive 3D kinematic analysis of knee joints.

    Science.gov (United States)

    Masum, Md Abdullah; Lambert, Andrew J; Pickering, Mark R; Scarvell, J M; Smith, P N

    2012-01-01

    Currently the standard clinical practice for measuring the motion of bones in a knee joint with sufficient precision involves implanting tantalum beads into the bones to act as fiducial markers prior to imaging using X-ray equipment. This procedure is invasive in nature and exposure to ionizing radiation imposes a cancer risk and the patient's movements are confined to a narrow field of view. In this paper, an ultrasound based system for non-invasive kinematic evaluation of knee joints is proposed. The results of an initial analysis show that this system can provide the precision required for non-invasive motion analysis while the patient performs normal physical activities.

  3. Non-invasive detection of aortic and coronary atherosclerosis in homozygous familial hypercholesterolemia by 64 slice multi-detector row computed tomography angiography

    Science.gov (United States)

    Homozygous familial hypercholesterolemia (HoFH) is a rare disorder characterized by the early onset of atherosclerosis, often at the ostia of coronary arteries. In this study we document for the first time that aortic and coronary atherosclerosis can be detected using 64 slice multiple detector row ...

  4. 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

  5. Unraveling the complexities of invasive multimodality neuromonitoring.

    Science.gov (United States)

    Sinha, Saurabh; Hudgins, Eric; Schuster, James; Balu, Ramani

    2017-11-01

    Acute brain injuries are a major cause of death and disability worldwide. Survivors of life-threatening brain injury often face a lifetime of dependent care, and novel approaches that improve outcome are sorely needed. A delayed cascade of brain damage, termed secondary injury, occurs hours to days and even weeks after the initial insult. This delayed phase of injury provides a crucial window for therapeutic interventions that could limit brain damage and improve outcome. A major barrier in the ability to prevent and treat secondary injury is that physicians are often unable to target therapies to patients' unique cerebral physiological disruptions. Invasive neuromonitoring with multiple complementary physiological monitors can provide useful information to enable this tailored, precision approach to care. However, integrating the multiple streams of time-varying data is challenging and often not possible during routine bedside assessment. The authors review and discuss the principles and evidence underlying several widely used invasive neuromonitors. They also provide a framework for integrating data for clinical decision making and discuss future developments in informatics that may allow new treatment paradigms to be developed.

  6. 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.)

  7. 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)

  8. 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.

  9. 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

  10. 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.

  11. Combined use of 64-slice computed tomography angiography and gated myocardial perfusion SPECT for the detection of functionally relevant coronary artery stenoses. First results in a clinical setting concerning patients with stable angina

    International Nuclear Information System (INIS)

    Hacker, M.; Hack, N.; Tiling, R.; Jakobs, T.; Nikolaou, K.; Becker, C.; Ziegler, F. von; Knez, A.; Koenig, A.; Klauss, V.

    2007-01-01

    Aim: In patients with stable angina pectoris both morphological and functional information about the coronary artery tree should be present before revascularization therapy is performed. High accuracy was shown for spiral computed tomography (MDCT) angiography acquired with a 64-slice CT scanner compared to invasive coronary angiography (ICA) in detecting obstructive'' coronary artery disease (CAD). Gated myocardial SPECT (MPI) is an established method for the noninvasive assessment of functional significance of coronary stenoses. Aim of the study was to evaluate the combination of 64-slice CT angiography plus MPI in comparison to ICA plus MPI in the detection of hemodynamically relevant coronary artery stenoses in a clinical setting. Patients, methods: 30 patients (63 ± 10.8 years, 23 men) with stable angina (21 with suspected, 9 with known CAD) were investigated. MPI, 64-slice CT angiography and ICA were performed, reversible and fixed perfusion defects were allocated to determining lesions separately for MDCT angiography and ICA. The combination of MDCT angiography plus MPI was compared to the results of ICA plus MPI. Results: Sensitivity, specificity, negative and positive predictive value for the combination of MDCT angiography plus MPI was 85%, 97%, 98% and 79%, respectively, on a vessel-based and 93%, 87%, 93% and 88%, respectively, on a patient-based level. 19 coronary arteries with stenoses =50% in both ICA and MDCT angiography showed no ischemia in MPI. Conclusion: The combination of 64-slice CT angiography and gated myocardial SPECT enabled a comprehensive non-invasive view of the anatomical and functional status of the coronary artery tree. (orig.)

  12. Combined use of 64-slice computed tomography angiography and gated myocardial perfusion SPECT for the detection of functionally relevant coronary artery stenoses. First results in a clinical setting concerning patients with stable angina

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, M.; Hack, N.; Tiling, R. [Klinikum Grosshadern (Germany). Dept. of Nuclear Medicine; Jakobs, T.; Nikolaou, K.; Becker, C. [Klinikum Grosshadern (Germany). Dept. of Clinical Radiology; Ziegler, F. von; Knez, A. [Klinikum Grosshadern (Germany). Dept. of Cardiology; Koenig, A.; Klauss, V. [Medizinische Poliklinik-Innenstadt, Univ. of Munich (Germany). Dept. of Cardiology

    2007-07-01

    Aim: In patients with stable angina pectoris both morphological and functional information about the coronary artery tree should be present before revascularization therapy is performed. High accuracy was shown for spiral computed tomography (MDCT) angiography acquired with a 64-slice CT scanner compared to invasive coronary angiography (ICA) in detecting ''obstructive'' coronary artery disease (CAD). Gated myocardial SPECT (MPI) is an established method for the noninvasive assessment of functional significance of coronary stenoses. Aim of the study was to evaluate the combination of 64-slice CT angiography plus MPI in comparison to ICA plus MPI in the detection of hemodynamically relevant coronary artery stenoses in a clinical setting. Patients, methods: 30 patients (63 {+-} 10.8 years, 23 men) with stable angina (21 with suspected, 9 with known CAD) were investigated. MPI, 64-slice CT angiography and ICA were performed, reversible and fixed perfusion defects were allocated to determining lesions separately for MDCT angiography and ICA. The combination of MDCT angiography plus MPI was compared to the results of ICA plus MPI. Results: Sensitivity, specificity, negative and positive predictive value for the combination of MDCT angiography plus MPI was 85%, 97%, 98% and 79%, respectively, on a vessel-based and 93%, 87%, 93% and 88%, respectively, on a patient-based level. 19 coronary arteries with stenoses =50% in both ICA and MDCT angiography showed no ischemia in MPI. Conclusion: The combination of 64-slice CT angiography and gated myocardial SPECT enabled a comprehensive non-invasive view of the anatomical and functional status of the coronary artery tree. (orig.)

  13. Non-invasive brain-computer interface system: towards its application as assistive technology.

    Science.gov (United States)

    Cincotti, Febo; Mattia, Donatella; Aloise, Fabio; Bufalari, Simona; Schalk, Gerwin; Oriolo, Giuseppe; Cherubini, Andrea; Marciani, Maria Grazia; Babiloni, Fabio

    2008-04-15

    The quality of life of people suffering from severe motor disabilities can benefit from the use of current assistive technology capable of ameliorating communication, house-environment management and mobility, according to the user's residual motor abilities. Brain-computer interfaces (BCIs) are systems that can translate brain activity into signals that control external devices. Thus they can represent the only technology for severely paralyzed patients to increase or maintain their communication and control options. Here we report on a pilot study in which a system was implemented and validated to allow disabled persons to improve or recover their mobility (directly or by emulation) and communication within the surrounding environment. The system is based on a software controller that offers to the user a communication interface that is matched with the individual's residual motor abilities. Patients (n=14) with severe motor disabilities due to progressive neurodegenerative disorders were trained to use the system prototype under a rehabilitation program carried out in a house-like furnished space. All users utilized regular assistive control options (e.g., microswitches or head trackers). In addition, four subjects learned to operate the system by means of a non-invasive EEG-based BCI. This system was controlled by the subjects' voluntary modulations of EEG sensorimotor rhythms recorded on the scalp; this skill was learnt even though the subjects have not had control over their limbs for a long time. We conclude that such a prototype system, which integrates several different assistive technologies including a BCI system, can potentially facilitate the translation from pre-clinical demonstrations to a clinical useful BCI.

  14. Non-invasive electrical brain stimulation: from acute to late-stage treatment of central nervous system damage

    Directory of Open Access Journals (Sweden)

    Petra Henrich-Noack

    2017-01-01

    Full Text Available Non-invasive brain current stimulation (NIBS is a promising and versatile tool for inducing neuroplasticity, protection and functional rehabilitation of damaged neuronal systems. It is technically simple, requires no surgery, and has significant beneficial effects. However, there are various technical approaches for NIBS which influence neuronal networks in significantly different ways. Transcranial direct current stimulation (tDCS, alternating current stimulation (ACS and repetitive transcranial magnetic stimulation (rTMS all have been applied to modulate brain activity in animal experiments under normal and pathological conditions. Also clinical trials have shown that tDCS, rTMS and ACS induce significant behavioural effects and can – depending on the parameters chosen – enhance or decrease brain excitability and influence performance and learning as well as rehabilitation and protective mechanisms. The diverse phaenomena and partially opposing effects of NIBS are not yet fully understood and mechanisms of action need to be explored further in order to select appropriate parameters for a given task, such as current type and strength, timing, distribution of current densities and electrode position. In this review, we will discuss the various parameters which need to be considered when designing a NIBS protocol and will put them into context with the envisaged applications in experimental neurobiology and medicine such as vision restoration, motor rehabilitation and cognitive enhancement.

  15. 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.

  16. 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

  17. 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

  18. Accuracy assessment of Tri-plane B-mode ultrasound for non-invasive 3D kinematic analysis of knee joints.

    Science.gov (United States)

    Masum, Md Abdullah; Pickering, Mark; Lambert, Andrew; Scarvell, Jennie; Smith, Paul

    2014-08-26

    Currently the clinical standard for measuring the motion of the bones in knee joints with sufficient precision involves implanting tantalum beads into the bones. These beads appear as high intensity features in radiographs and can be used for precise kinematic measurements. This procedure imposes a strong coupling between accuracy and invasiveness. In this paper, a tri-plane B-mode ultrasound (US) based non-invasive approach is proposed for use in kinematic analysis of knee joints in 3D space. The 3D analysis is performed using image processing procedures on the 2D US slices. The novelty of the proposed procedure and its applicability to the unconstrained 3D kinematic analysis of knee joints is outlined. An error analysis for establishing the method's feasibility is included for different artificial compositions of a knee joint phantom. Some in-vivo and in-vitro scans are presented to demonstrate that US scans reveal enough anatomical details, which further supports the experimental setup used using knee bone phantoms. The error between the displacements measured by the registration of the US image slices and the true displacements of the respective slices measured using the precision mechanical stages on the experimental apparatus is evaluated for translation and rotation in two simulated environments. The mean and standard deviation of errors are shown in tabular form. This method provides an average measurement precision of less than 0.1 mm and 0.1 degrees, respectively. In this paper, we have presented a novel non-invasive approach to measuring the motion of the bones in a knee using tri-plane B-mode ultrasound and image registration. In our study, the image registration method determines the position of bony landmarks relative to a B-mode ultrasound sensor array with sub-pixel accuracy. The advantages of our proposed system over previous techniques are that it is non-invasive, does not require the use of ionizing radiation and can be used conveniently if

  19. A simple method for multiday imaging of slice cultures.

    Science.gov (United States)

    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.

  20. 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....

  1. Vascular Endothelial Growth Factor Receptor 1 Contributes to Escherichia coli K1 Invasion of Human Brain Microvascular Endothelial Cells through the Phosphatidylinositol 3-Kinase/Akt Signaling Pathway▿ †

    OpenAIRE

    Zhao, Wei-Dong; Liu, Wei; Fang, Wen-Gang; Kim, Kwang Sik; Chen, Yu-Hua

    2010-01-01

    Escherichia coli is the most common Gram-negative organism causing neonatal meningitis. Previous studies demonstrated that E. coli K1 invasion of brain microvascular endothelial cells (BMEC) is required for penetration into the central nervous system, but the microbe-host interactions that are involved in this process remain incompletely understood. Here we report the involvement of vascular endothelial growth factor receptor 1 (VEGFR1) expressed on human brain microvascular endothelial cells...

  2. Molecular and Microenvironmental Determinants of Glioma Stem-Like Cell Survival and Invasion

    Directory of Open Access Journals (Sweden)

    Alison Roos

    2017-06-01

    Full Text Available Glioblastoma multiforme (GBM is the most frequent primary brain tumor in adults with a 5-year survival rate of 5% despite intensive research efforts. The poor prognosis is due, in part, to aggressive invasion into the surrounding brain parenchyma. Invasion is a complex process mediated by cell-intrinsic pathways, extrinsic microenvironmental cues, and biophysical cues from the peritumoral stromal matrix. Recent data have attributed GBM invasion to the glioma stem-like cell (GSC subpopulation. GSCs are slowly dividing, highly invasive, therapy resistant, and are considered to give rise to tumor recurrence. GSCs are localized in a heterogeneous cellular niche, and cross talk between stromal cells and GSCs cultivates a fertile environment that promotes GSC invasion. Pro-migratory soluble factors from endothelial cells, astrocytes, macrophages, microglia, and non-stem-like tumor cells can stimulate peritumoral invasion of GSCs. Therefore, therapeutic efforts designed to target the invasive GSCs may enhance patient survival. In this review, we summarize the current understanding of extrinsic pathways and major stromal and immune players facilitating GSC maintenance and survival.

  3. Central Administration of Lipopolysaccharide Induces Depressive-like Behavior in Vivo and Activates Brain Indoleamine 2,3 Dioxygenase In Murine Organotypic Hippocampal Slice Cultures

    Directory of Open Access Journals (Sweden)

    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

  4. 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

  5. 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)

  6. 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).

  7. Preliminary experience with interactive guided brain biopsies using a vertically opened 0.5-T MR system

    International Nuclear Information System (INIS)

    Schneider, J.P.; Dietrich, J.; Lieberenz, S.; Schmidt, F.; Sorge, O.; Trantakis, C.; Seifert, V.; Kellermann, S.; Schober, R.; Franke, P.

    1999-01-01

    The purpose of our study was to evaluate the feasibility and accuracy of brain biopsies performed within a vertically opened MR system. We worked with the interventional 0.5-T MR ''SIGNA SP'' (General Electric Medical Systems, Milwaukee, Wis.) with an integrated tracking device ''Flashpoint Position Encoder'' (Image Guided Technologies, USA). As a holding device for this instrument we constructed a special frame. The whole system allows an exact adjustment of an optimum biopsy direction and guidance of the biopsy in a non-stereotactic, interactive mode in near real-time. As biopsy tools we used MR-compatible aspiration and specially made side-cut needles (Daum, Germany; E-Z-EM, USA). We performed a prospective diagnostic brain biopsy study in 18 patients. Guidance of the needle was carried out using gradient-echo single-slice technique. The sample was taken after controlling the exact position of the needle tip on spin-echo images. In 12 cases an exact neuropathological diagnosis was possible. In 6 cases of negative biopsy (4 aspiration biopsies) the samples were not representative. Our results demonstrate the feasibility of interactive MR-guided minimally invasive brain biopsies in an open MR system. The best results were achieved using cut needles for biopsies of contrast-enhancing lesions visible on T1-weighted gradient-echo guidance sequence. (orig.)

  8. 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.

  9. Gastric metastasis of triple negative invasive lobular carcinoma

    OpenAIRE

    Caglayan Geredeli; Osman Dogru; Ethem Omeroglu; Farise Yilmaz; Faruk Cicekci

    2015-01-01

    Invasive lobular carcinomas are the second most common type (5% to 15%) of invasive breast carcinomas. The most frequent sites of breast cancer metastasis are the local and distant lymph nodes, brain, lung, liver, and bones; metastasis to the gastrointestinal system, especially to the stomach, is rare. When a mass is detected in an unusual place in a patient with invasive lobular carcinoma, it should be kept in mind that such a mass may be either a second primary carcinoma or the metastasis o...

  10. 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.

  11. 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

  12. Modeling and Realization of a Bearingless Flux-Switching Slice Motor

    Directory of Open Access Journals (Sweden)

    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.

  13. 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

  14. 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

  15. Non invasive Brain-Computer Interface system: towards its application as assistive technology

    Science.gov (United States)

    Cincotti, Febo; Mattia, Donatella; Aloise, Fabio; Bufalari, Simona; Schalk, Gerwin; Oriolo, Giuseppe; Cherubini, Andrea; Marciani, Maria Grazia; Babiloni, Fabio

    2010-01-01

    The quality of life of people suffering from severe motor disabilities can benefit from the use of current assistive technology capable of ameliorating communication, house-environment management and mobility, according to the user's residual motor abilities. Brain Computer Interfaces (BCIs) are systems that can translate brain activity into signals that control external devices. Thus they can represent the only technology for severely paralyzed patients to increase or maintain their communication and control options. Here we report on a pilot study in which a system was implemented and validated to allow disabled persons to improve or recover their mobility (directly or by emulation) and communication within the surrounding environment. The system is based on a software controller that offers to the user a communication interface that is matched with the individual's residual motor abilities. Patients (n=14) with severe motor disabilities due to progressive neurodegenerative disorders were trained to use the system prototype under a rehabilitation program carried out in a house-like furnished space. All users utilized regular assistive control options (e.g., microswitches or head trackers). In addition, four subjects learned to operate the system by means of a non-invasive EEG-based BCI. This system was controlled by the subjects' voluntary modulations of EEG sensorimotor rhythms recorded on the scalp; this skill was learnt even though the subjects have not had control over their limbs for a long time. We conclude that such a prototype system, which integrates several different assistive technologies including a BCI system, can potentially facilitate the translation from pre-clinical demonstrations to a clinical useful BCI. PMID:18394526

  16. 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

  17. 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%.

  18. 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

  19. 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 ...

  20. Whole-Genome Sequencing of Invasion-Resistant Cells Identifies Laminin α2 as a Host Factor for Bacterial Invasion

    DEFF Research Database (Denmark)

    van Wijk, Xander M.; Döhrmann, Simon; Hallstrom, Bjorn

    2017-01-01

    cells. Whole-genome sequencing and transcriptome sequencing (RNA-Seq) uncovered a deletion in the gene encoding the laminin subunit α2 (Lama2) that eliminated much of domain L4a. Silencing of the long Lama2 isoform in wild-type cells strongly reduced bacterial invasion, whereas transfection with human...... LAMA2 cDNA significantly enhanced invasion in pgsA745 cells. The addition of exogenous laminin-α2β1γ1/laminin-α2β2γ1 strongly increased bacterial invasion in CHO cells, as well as in human alveolar basal epithelial and human brain microvascular endothelial cells. Thus, the L4a domain in laminin α2...

  1. [Anatomy of the skull base and the cranial nerves in slice imaging].

    Science.gov (United States)

    Bink, A; Berkefeld, J; Zanella, F

    2009-07-01

    Computed tomography (CT) and magnetic resonance imaging (MRI) are suitable methods for examination of the skull base. Whereas CT is used to evaluate mainly bone destruction e.g. for planning surgical therapy, MRI is used to show pathologies in the soft tissue and bone invasion. High resolution and thin slice thickness are indispensible for both modalities of skull base imaging. Detailed anatomical knowledge is necessary even for correct planning of the examination procedures. This knowledge is a requirement to be able to recognize and interpret pathologies. MRI is the method of choice for examining the cranial nerves. The total path of a cranial nerve can be visualized by choosing different sequences taking into account the tissue surrounding this cranial nerve. This article summarizes examination methods of the skull base in CT and MRI, gives a detailed description of the anatomy and illustrates it with image examples.

  2. Anatomy of the skull base and the cranial nerves in slice imaging

    International Nuclear Information System (INIS)

    Bink, A.; Berkefeld, J.; Zanella, F.

    2009-01-01

    Computed tomography (CT) and magnetic resonance imaging (MRI) are suitable methods for examination of the skull base. Whereas CT is used to evaluate mainly bone destruction e.g. for planning surgical therapy, MRI is used to show pathologies in the soft tissue and bone invasion. High resolution and thin slice thickness are indispensible for both modalities of skull base imaging. Detailed anatomical knowledge is necessary even for correct planning of the examination procedures. This knowledge is a requirement to be able to recognize and interpret pathologies. MRI is the method of choice for examining the cranial nerves. The total path of a cranial nerve can be visualized by choosing different sequences taking into account the tissue surrounding this cranial nerve. This article summarizes examination methods of the skull base in CT and MRI, gives a detailed description of the anatomy and illustrates it with image examples. (orig.) [de

  3. 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.

  4. 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

  5. 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

  6. Registration-based approach for reconstruction of high-resolution in utero fetal MR brain images.

    Science.gov (United States)

    Rousseau, Francois; Glenn, Orit A; Iordanova, Bistra; Rodriguez-Carranza, Claudia; Vigneron, Daniel B; Barkovich, James A; Studholme, Colin

    2006-09-01

    This paper describes a novel approach to forming high-resolution MR images of the human fetal brain. It addresses the key problem of fetal motion by proposing a registration-refined compounding of multiple sets of orthogonal fast two-dimensional MRI slices, which are currently acquired for clinical studies, into a single high-resolution MRI volume. A robust multiresolution slice alignment is applied iteratively to the data to correct motion of the fetus that occurs between two-dimensional acquisitions. This is combined with an intensity correction step and a super-resolution reconstruction step, to form a single high isotropic resolution volume of the fetal brain. Experimental validation on synthetic image data with known motion types and underlying anatomy, together with retrospective application to sets of clinical acquisitions, are included. Results indicate that this method promises a unique route to acquiring high-resolution MRI of the fetal brain in vivo allowing comparable quality to that of neonatal MRI. Such data provide a highly valuable window into the process of normal and abnormal brain development, which is directly applicable in a clinical setting.

  7. On the relative merits of invasive and non-invasive pre-surgical brain mapping: New tools in ablative epilepsy surgery.

    Science.gov (United States)

    Papanicolaou, Andrew C; Rezaie, Roozbeh; Narayana, Shalini; Choudhri, Asim F; Abbas-Babajani-Feremi; Boop, Frederick A; Wheless, James W

    2018-05-01

    Cortical Stimulation Mapping (CSM) and the Wada procedure have long been considered the gold standard for localizing motor and language-related cortical areas and for determining the language and memory-dominant hemisphere, respectively. In recent years, however, non-invasive methods such as magnetoencephalography (MEG), functional magnetic resonance imaging (fMRI), and transcranial magnetic stimulation (TMS) have emerged as promising alternatives to the aforementioned procedures, particularly in cases where the invasive localization of eloquent cortex has proven to be challenging. To illustrate this point, we will first introduce the evidence of the compatibility of invasive and non-invasive methods and subsequently outline the rationale and the conditions where the latter methods are applicable. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Gd-DTPA T1 relaxivity in brain tissue obtained by convection-enhanced delivery, magnetic resonance imaging and emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Haar, Peter J [Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA (United States); Broaddus, William C; Chen Zhijian; Gillies, George T [Department of Neurosurgery, Virginia Commonwealth University, Richmond, VA (United States); Fatouros, Panos P; Corwin, Frank D, E-mail: wbroaddus@mcvh-vcu.ed [Department of Radiology, Virginia Commonwealth University, Richmond, VA (United States)

    2010-06-21

    A common approach to quantify gadolinium (Gd) contrast agents involves measuring the post-contrast change in T1 rate and then using the constant T1 relaxivity R to determine the contrast agent concentration. Because this method is fast and non-invasive, it could be potentially valuable in many areas of brain research. However, to accurately measure contrast agent concentrations in the brain, the T1 relaxivity R of the specific agent must be accurately known. Furthermore, the macromolecular content and compartmentalization of the brain extracellular space (ECS) are expected to significantly alter R from values measured in aqueous solutions. In this study, the T1 relaxivity R of gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) was measured following direct interstitial infusions of three different contrast agent concentrations to the parenchyma of rat brains. Changes in magnetic resonance (MR) T1 values were compared to brain slice concentrations determined with inductively coupled plasma atomic emission spectroscopy (ICP-AES) to determine R in 15 rats. Additionally, samples of cerebrospinal fluid, blood and urine were analyzed to evaluate possible Gd-DTPA clearance from the brain. The T1 relaxivity R of Gd-DTPA in the brain ECS was measured to be 5.35 (mM s){sup -1} in a 2.4 T field. This value is considerably higher than estimations used in studies by other groups. Measurements of brain Gd-DTPA tissue concentrations using MRI and ICP-AES demonstrated a high degree of coincidence. Clearance of Gd-DTPA was minimal at the time point immediately after infusion. These results suggest that the environment of the brain does in fact significantly affect Gd T1 relaxivity, and that MRI can accurately measure contrast agent concentrations when this relaxivity is well characterized.

  9. Gd-DTPA T1 relaxivity in brain tissue obtained by convection-enhanced delivery, magnetic resonance imaging and emission spectroscopy

    Science.gov (United States)

    Haar, Peter J.; Broaddus, William C.; Chen, Zhi-jian; Fatouros, Panos P.; Gillies, George T.; Corwin, Frank D.

    2010-06-01

    A common approach to quantify gadolinium (Gd) contrast agents involves measuring the post-contrast change in T1 rate and then using the constant T1 relaxivity R to determine the contrast agent concentration. Because this method is fast and non-invasive, it could be potentially valuable in many areas of brain research. However, to accurately measure contrast agent concentrations in the brain, the T1 relaxivity R of the specific agent must be accurately known. Furthermore, the macromolecular content and compartmentalization of the brain extracellular space (ECS) are expected to significantly alter R from values measured in aqueous solutions. In this study, the T1 relaxivity R of gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) was measured following direct interstitial infusions of three different contrast agent concentrations to the parenchyma of rat brains. Changes in magnetic resonance (MR) T1 values were compared to brain slice concentrations determined with inductively coupled plasma atomic emission spectroscopy (ICP-AES) to determine R in 15 rats. Additionally, samples of cerebrospinal fluid, blood and urine were analyzed to evaluate possible Gd-DTPA clearance from the brain. The T1 relaxivity R of Gd-DTPA in the brain ECS was measured to be 5.35 (mM s)-1 in a 2.4 T field. This value is considerably higher than estimations used in studies by other groups. Measurements of brain Gd-DTPA tissue concentrations using MRI and ICP-AES demonstrated a high degree of coincidence. Clearance of Gd-DTPA was minimal at the time point immediately after infusion. These results suggest that the environment of the brain does in fact significantly affect Gd T1 relaxivity, and that MRI can accurately measure contrast agent concentrations when this relaxivity is well characterized.

  10. Gd-DTPA T1 relaxivity in brain tissue obtained by convection-enhanced delivery, magnetic resonance imaging and emission spectroscopy

    International Nuclear Information System (INIS)

    Haar, Peter J; Broaddus, William C; Chen Zhijian; Gillies, George T; Fatouros, Panos P; Corwin, Frank D

    2010-01-01

    A common approach to quantify gadolinium (Gd) contrast agents involves measuring the post-contrast change in T1 rate and then using the constant T1 relaxivity R to determine the contrast agent concentration. Because this method is fast and non-invasive, it could be potentially valuable in many areas of brain research. However, to accurately measure contrast agent concentrations in the brain, the T1 relaxivity R of the specific agent must be accurately known. Furthermore, the macromolecular content and compartmentalization of the brain extracellular space (ECS) are expected to significantly alter R from values measured in aqueous solutions. In this study, the T1 relaxivity R of gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) was measured following direct interstitial infusions of three different contrast agent concentrations to the parenchyma of rat brains. Changes in magnetic resonance (MR) T1 values were compared to brain slice concentrations determined with inductively coupled plasma atomic emission spectroscopy (ICP-AES) to determine R in 15 rats. Additionally, samples of cerebrospinal fluid, blood and urine were analyzed to evaluate possible Gd-DTPA clearance from the brain. The T1 relaxivity R of Gd-DTPA in the brain ECS was measured to be 5.35 (mM s) -1 in a 2.4 T field. This value is considerably higher than estimations used in studies by other groups. Measurements of brain Gd-DTPA tissue concentrations using MRI and ICP-AES demonstrated a high degree of coincidence. Clearance of Gd-DTPA was minimal at the time point immediately after infusion. These results suggest that the environment of the brain does in fact significantly affect Gd T1 relaxivity, and that MRI can accurately measure contrast agent concentrations when this relaxivity is well characterized.

  11. Control of synthesis and release of radioactive acetylcholine in brain slices from the rat. Effects of neurotropic drugs

    Science.gov (United States)

    Grewaal, D. S.; Quastel, J. H.

    1973-01-01

    1. Studies of the synthesis and release of radioactive acetylcholine in rat brain-cortex slices incubated in Locke–bicarbonate–[U-14C]glucose media, containing paraoxon as cholinesterase inhibitor, revealed the following phenomena: (a) dependence of K+-or protoveratrine-stimulated acetylcholine synthesis and release on the presence of Na+ and Ca2+ in the incubation medium, (b) enhanced release of radioactive acetylcholine by substances that promote depolarization at the nerve cell membrane (e.g. high K+, ouabain, protoveratrine, sodium l-glutamate, high concentration of acetylcholine), (c) failure of acetylcholine synthesis to keep pace with acetylcholine release under certain conditions (e.g. the presence of ouabain or lack of Na+). 2. Stimulation by K+ of radioactive acetylcholine synthesis was directly proportional to the external concentration of Na+, but some synthesis and release of radioactive acetylcholine occurred in the absence of Na+ as well as in the absence of Ca2+. 3. The Na+ dependence of K+-stimulated acetylcholine synthesis was partly due to suppression of choline transport, as addition of small concentrations of choline partly neutralized the effect of Na+ lack, and partly due to the suppression of the activity of the Na+ pump. 4. Protoveratrine caused a greatly increased release of radioactive acetylcholine without stimulating total radioactive acetylcholine synthesis. Protoveratrine was ineffective in the absence of Ca2+ from the incubation medium. It completely blocked K+ stimulation of acetylcholine synthesis and release. 5. Tetrodotoxin abolished the effects of protoveratrine on acetylcholine release. It had blocking effects (partial or complete) on the action of high K+, sodium l-glutamate and lack of Ca2+ on acetylcholine synthesis and release. 6. Unlabelled exogenous acetylcholine did not diminish the content of labelled tissue acetylcholine, derived from labelled glucose, suggesting that no exchange with vesicular acetylcholine took

  12. Surface-associated plasminogen binding of Cryptococcus neoformans promotes extracellular matrix invasion.

    Directory of Open Access Journals (Sweden)

    Jamal Stie

    2009-06-01

    Full Text Available The fungal pathogen Cryptococcus neoformans is a leading cause of illness and death in persons with predisposing factors, including: malignancies, solid organ transplants, and corticosteroid use. C. neoformans is ubiquitous in the environment and enters into the lungs via inhalation, where it can disseminate through the bloodstream and penetrate the central nervous system (CNS, resulting in a difficult to treat and often-fatal infection of the brain, called meningoencephalitis. Plasminogen is a highly abundant protein found in the plasma component of blood and is necessary for the degradation of fibrin, collagen, and other structural components of tissues. This fibrinolytic system is utilized by cancer cells during metastasis and several pathogenic species of bacteria have been found to manipulate the host plasminogen system to facilitate invasion of tissues during infection by modifying the activation of this process through the binding of plasminogen at their surface.The invasion of the brain and the central nervous system by penetration of the protective blood-brain barrier is a prerequisite to the establishment of meningoencephalitis by the opportunistic fungal pathogen C. neoformans. In this study, we examined the ability of C. neoformans to subvert the host plasminogen system to facilitate tissue barrier invasion. Through a combination of biochemical, cell biology, and proteomic approaches, we have shown that C. neoformans utilizes the host plasminogen system to cross tissue barriers, providing support for the hypothesis that plasminogen-binding may contribute to the invasion of the blood-brain barrier by penetration of the brain endothelial cells and underlying matrix. In addition, we have identified the cell wall-associated proteins that serve as plasminogen receptors and characterized both the plasminogen-binding and plasmin-activation potential for this significant human pathogen.The results of this study provide evidence for the

  13. White matter segmentation by estimating tissue optical attenuation from volumetric OCT massive histology of whole rodent brains

    Science.gov (United States)

    Lefebvre, Joël.; Castonguay, Alexandre; Lesage, Frédéric

    2017-02-01

    A whole rodent brain was imaged using an automated massive histology setup and an Optical Coherence Tomography (OCT) microscope. Thousands of OCT volumetric tiles were acquired, each covering a size of about 2.5x2.5x0.8 mm3 with a sampling resolution of 4.9x4.9x6.5 microns. This paper shows the techniques for reconstruction, attenuation compensation and segmentation of the sliced brains. The tile positions within the mosaic were evaluated using a displacement model of the motorized stage and pairwise coregistration. Volume blending was then performed by solving the 3D Laplace equation, and consecutive slices were assembled using the cross-correlation of their 2D image gradient. This reconstruction algorithm resulted in a 3D map of optical reflectivity for the whole brain at micrometric resolution. OCT tissue slices were then used to estimate the local attenuation coefficient based on a single scattering photon model. The attenuation map obtained exhibits a high contrast for all white matter fibres, regardless of their orientation. The tissue optical attenuation from the intrinsic OCT reflectivity contributes to better white matter tissue segmentation. The combined 3D maps of reflectivity and attenuation is a step toward the study of white matter at a microscopic scale for the whole brain in small animals.

  14. A Cross-Platform Smartphone Brain Scanner

    DEFF Research Database (Denmark)

    Larsen, Jakob Eg; Stopczynski, Arkadiusz; Stahlhut, Carsten

    We describe a smartphone brain scanner with a low-costwireless 14-channel Emotiv EEG neuroheadset interfacingwith multiple mobile devices. This personal informaticssystem enables minimally invasive and continuouscapturing of brain imaging data in natural settings. Thesystem applies an inverse...

  15. Insulin and the brain.

    Science.gov (United States)

    Derakhshan, Fatemeh; Toth, Cory

    2013-03-01

    Mainly known for its role in peripheral glucose homeostasis, insulin has also significant impact within the brain, functioning as a key neuromodulator in behavioral, cellular, biochemical and molecular studies. The brain is now regarded as an insulin-sensitive organ with widespread, yet selective, expression of the insulin receptor in the olfactory bulb, hypothalamus, hippocampus, cerebellum, amygdala and cerebral cortex. Insulin receptor signaling in the brain is important for neuronal development, glucoregulation, feeding behavior, body weight, and cognitive processes such as with attention, executive functioning, learning and memory. Emerging evidence has demonstrated insulin receptor signaling to be impaired in several neurological disorders. Moreover, insulin receptor signaling is recognized as important for dendritic outgrowth, neuronal survival, circuit development, synaptic plasticity and postsynaptic neurotransmitter receptor trafficking. We review the multiple roles of insulin in the brain, as well as its endogenous trafficking to the brain or its exogenous intervention. Although insulin can be directly targeted to the brain via intracerebroventricular (ICV) or intraparenchymal delivery, these invasive techniques are with significant risk, necessitating repeated surgical intervention and providing potential for systemic hypoglycemia. Another method, intranasal delivery, is a non-invasive, safe, and alternative approach which rapidly targets delivery of molecules to the brain while minimizing systemic exposure. Over the last decades, the delivery of intranasal insulin in animal models and human patients has evolved and expanded, permitting new hope for associated neurodegenerative and neurovascular disorders.

  16. Ketamine attenuates the glutamatergic neurotransmission in the ventral posteromedial nucleus slices of rats.

    Science.gov (United States)

    Fu, Bao; Liu, Chengxi; Zhang, Yajun; Fu, Xiaoyun; Zhang, Lin; Yu, Tian

    2017-08-23

    Ketamine is a frequently used intravenous anesthetic, which can reversibly induce loss of consciousness (LOC). Previous studies have demonstrated that thalamocortical system is critical for information transmission and integration in the brain. The ventral posteromedial nucleus (VPM) is a critical component of thalamocortical system. Glutamate is an important excitatory neurotransmitter in the brain and may be involved in ketamine-induced LOC. The study used whole-cell patch-clamp to observe the effect of ketamine (30 μM-1000 μM) on glutamatergic neurotransmission in VPM slices. Ketamine significantly decreased the amplitude of glutamatergic spontaneous excitatory postsynaptic currents (sEPSCs), but only higher concentration of ketamine (300 μM and 1000 μM) suppressed the frequency of sEPSCs. Ketamine (100 μM-1000 μM) also decreased the amplitude of glutamatergic miniature excitatory postsynaptic currents (mEPSCs), without altering the frequency. In VPM neurons, ketamine attenuates the glutamatergic neurotransmission mainly through postsynaptic mechanism and action potential may be involved in the process.

  17. Invasive aspergillosis in near drowning nonneutropenic patient.

    Science.gov (United States)

    Munta, Kartik; Gopal, Palepu B N; Vigg, Ajit

    2015-12-01

    Invasive aspergillosis in immunosuppressed people has been well documented, but to diagnose and treat in an immunocompetent individual after near drowning, it requires early suspicion and proper empirical treatment. We report a case diagnosed to have invasive aspergillosis with systemic dissemination of the infection to the brain, gluteal muscles, and kidneys after a fall in a chemical tank of a paper manufacturing company. He was ventilated for acute respiratory distress syndrome and managed with antibiotics and vasopressors. Due to nonresolving pneumonia and positive serum galactomannan, trans-tracheal biopsy was performed which confirmed invasive aspergillosis and was treated with antifungals. With the availability of galactomannan assay and better radiological investigative modalities, occurrence of such invasive fungal infections in cases of drowning patients should be considered early in such patients and treated with appropriate antifungals.

  18. Cells in human postmortem brain tissue slices remain alive for several weeks in culture

    NARCIS (Netherlands)

    Verwer, Ronald W. H.; Hermens, Wim T. J. M. C.; Dijkhuizen, PaulaA; ter Brake, Olivier; Baker, Robert E.; Salehi, Ahmad; Sluiter, Arja A.; Kok, Marloes J. M.; Muller, Linda J.; Verhaagen, Joost; Swaab, Dick F.

    2002-01-01

    Animal models for human neurological and psychiatric diseases only partially mimic the underlying pathogenic processes. Therefore, we investigated the potential use of cultured postmortem brain tissue from adult neurological patients and controls. The present study shows that human brain tissue

  19. Resource slicing in virtual wireless networks: a survey

    OpenAIRE

    Richart, Matias; Baliosian De Lazzari, Javier Ernesto; Serrat Fernández, Juan; Gorricho Moreno, Juan Luis

    2016-01-01

    New architectural and design approaches for radio access networks have appeared with the introduction of network virtualization in the wireless domain. One of these approaches splits the wireless network infrastructure into isolated virtual slices under their own management, requirements, and characteristics. Despite the advances in wireless virtualization, there are still many open issues regarding the resource allocation and isolation of wireless slices. Because of the dynamics and share...

  20. A testbed to explore the optimal electrical stimulation parameters for suppressing inter-ictal spikes in human hippocampal slices.

    Science.gov (United States)

    Min-Chi Hsiao; Pen-Ning Yu; Dong Song; Liu, Charles Y; Heck, Christi N; Millett, David; Berger, Theodore W

    2014-01-01

    New interventions using neuromodulatory devices such as vagus nerve stimulation, deep brain stimulation and responsive neurostimulation are available or under study for the treatment of refractory epilepsy. Since the actual mechanisms of the onset and termination of the seizure are still unclear, most researchers or clinicians determine the optimal stimulation parameters through trial-and-error procedures. It is necessary to further explore what types of electrical stimulation parameters (these may include stimulation frequency, amplitude, duration, interval pattern, and location) constitute a set of optimal stimulation paradigms to suppress seizures. In a previous study, we developed an in vitro epilepsy model using hippocampal slices from patients suffering from mesial temporal lobe epilepsy. Using a planar multi-electrode array system, inter-ictal activity from human hippocampal slices was consistently recorded. In this study, we have further transferred this in vitro seizure model to a testbed for exploring the possible neurostimulation paradigms to inhibit inter-ictal spikes. The methodology used to collect the electrophysiological data, the approach to apply different electrical stimulation parameters to the slices are provided in this paper. The results show that this experimental testbed will provide a platform for testing the optimal stimulation parameters of seizure cessation. We expect this testbed will expedite the process for identifying the most effective parameters, and may ultimately be used to guide programming of new stimulating paradigms for neuromodulatory devices.

  1. Verification-Driven Slicing of UML/OCL Models

    DEFF Research Database (Denmark)

    Shaikh, Asadullah; Clarisó Viladrosa, Robert; Wiil, Uffe Kock

    2010-01-01

    computational complexity can limit their scalability. In this paper, we consider a specific static model (UML class diagrams annotated with unrestricted OCL constraints) and a specific property to verify (satisfiability, i.e., “is it possible to create objects without violating any constraint?”). Current...... approaches to this problem have an exponential worst-case runtime. We propose a technique to improve their scalability by partitioning the original model into submodels (slices) which can be verified independently and where irrelevant information has been abstracted. The definition of the slicing procedure...

  2. Brain anti-cytoxic edema agents.

    Science.gov (United States)

    Kimelberg, H K; Barron, K D; Bourke, R S; Nelson, L R; Cragoe, E J

    1990-01-01

    The work described in this chapter has indicated that improved outcome from an experimental head injury model can be achieved by drugs which are non-diuretic derivatives of loop diuretics, namely indanyl and fluorenyl compounds which are derivatives of ethacrynic acid. These drugs were originally identified by us on the basis of their efficacy in inhibiting [K+]-stimulated, HCO3(-)-dependent swelling of brain cerebrocortical slices. Swelling of glial cells (astrocytes) has long been known to be associated with such slice swelling and astrocyte swelling is a major locus of cytotoxic or cellular brain edema. Qualitative and quantitative electron microscope studies have shown that L644,711, a particularly effective member of the fluorenyl class of drugs, inhibits astrocytic swelling associated with an experimental animal head injury model. We have suggested that astrocytic swelling in pathological states may be partly due to activation of Cl-/HCO3- and Na+/H+ exchange systems driven by increased astrocytic intracellular hydration of CO2, and recent work has indeed shown that the ability of the indanyl and fluorenyl drugs to inhibit brain slice swelling and protect against head injury correlates closely with their ability to inhibit Cl-/HCO3- exchange. All these data suggest that astrocytic swelling, which seems to precede neuronal degeneration and breakdown of the blood-brain barrier, is deleterious and that prevention of such swelling can lead to effective therapy. We have used primary astrocytic cultures to explore reasons why astrocytic swelling could be harmful. Exposing such astrocytes to hypotonic medium causes rapid swelling with a slower return to normal volume in the continued presence of hypotonic medium, a process known as regulatory volume decrease or RVD. Such RVD is associated with marked release of several amino acids, including L-glutamate. L644,711 and other Cl-/HCO3- transport inhibitors such as SITS and furosemide, but not the selective Na+ + K+ + 2

  3. One-stop shop assessment for atrial septal defect closure using 256-slice coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Yamasaki, Yuzo; Kamitani, Takeshi; Sagiyama, Koji; Yamanouchi, Torahiko; Honda, Hiroshi [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka (Japan); Nagao, Michinobu; Kawanami, Satoshi [Kyushu University, Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Fukuoka (Japan); Sakamoto, Ichiro [Kyushu University, Department of Cardiovascular Medicine, Graduate School of Medical Sciences, Fukuoka (Japan); Yamamura, Kenichiro [Kyushu University, Department of Pediatrics, Graduate School of Medical Sciences, Fukuoka (Japan); Yabuuchi, Hidetake [Kyushu University, Department of Health Sciences, Graduate School of Medical Sciences, Fukuoka (Japan)

    2017-02-15

    To investigate the feasibility and accuracy of measurement of the pulmonary to systemic blood flow ratio (Qp/Qs) and defect and rim sizes in secundum atrial septal defects (ASDs) using 256-slice CT, compared to the reference transoesophageal echocardiography (TEE) and right heart catheterization (RHC) measurements. Twenty-three consecutive adult patients with secundum ASDs who underwent retrospective ECG-gated coronary CT angiography (CCTA), TEE and RHC were enrolled in this study. Right ventricular (RV) and left ventricular (LV) stroke volumes (SV) were calculated by biventricular volumetry of CCTA. Qp/Qs-CT was defined as RVSV/LVSV. The sizes of the defect and rim were measured by multi-planar reconstruction CT images. Correlations between Qp/Qs-CT and Qp/Qs-RHC and between the defect diameter obtained by CT and TEE were analyzed by Pearson's coefficient analysis. Rim sizes by CT and TEE were compared by paired t-test. Qp/Qs-CT was significantly correlated with Qp/Qs-RHC (r = 0.83, p < 0.0001), and the defect diameter by CT was significantly correlated with that by TEE (r = 0.95, p < 0.0001). There was no significant difference between CT and TEE in measurements of rim size. 256-slice CCTA allows measuring Qp/Qs and size of defects and rims in patients with secundum ASDs, accomplishing pretreatment evaluation non-invasively and comprehensively. (orig.)

  4. One-stop shop assessment for atrial septal defect closure using 256-slice coronary CT angiography

    International Nuclear Information System (INIS)

    Yamasaki, Yuzo; Kamitani, Takeshi; Sagiyama, Koji; Yamanouchi, Torahiko; Honda, Hiroshi; Nagao, Michinobu; Kawanami, Satoshi; Sakamoto, Ichiro; Yamamura, Kenichiro; Yabuuchi, Hidetake

    2017-01-01

    To investigate the feasibility and accuracy of measurement of the pulmonary to systemic blood flow ratio (Qp/Qs) and defect and rim sizes in secundum atrial septal defects (ASDs) using 256-slice CT, compared to the reference transoesophageal echocardiography (TEE) and right heart catheterization (RHC) measurements. Twenty-three consecutive adult patients with secundum ASDs who underwent retrospective ECG-gated coronary CT angiography (CCTA), TEE and RHC were enrolled in this study. Right ventricular (RV) and left ventricular (LV) stroke volumes (SV) were calculated by biventricular volumetry of CCTA. Qp/Qs-CT was defined as RVSV/LVSV. The sizes of the defect and rim were measured by multi-planar reconstruction CT images. Correlations between Qp/Qs-CT and Qp/Qs-RHC and between the defect diameter obtained by CT and TEE were analyzed by Pearson's coefficient analysis. Rim sizes by CT and TEE were compared by paired t-test. Qp/Qs-CT was significantly correlated with Qp/Qs-RHC (r = 0.83, p < 0.0001), and the defect diameter by CT was significantly correlated with that by TEE (r = 0.95, p < 0.0001). There was no significant difference between CT and TEE in measurements of rim size. 256-slice CCTA allows measuring Qp/Qs and size of defects and rims in patients with secundum ASDs, accomplishing pretreatment evaluation non-invasively and comprehensively. (orig.)

  5. Slice through an LHC bending magnet

    CERN Multimedia

    Slice through an LHC superconducting dipole (bending) magnet. The slice includes a cut through the magnet wiring (niobium titanium), the beampipe and the steel magnet yokes. Particle beams in the Large Hadron Collider (LHC) have the same energy as a high-speed train, squeezed ready for collision into a space narrower than a human hair. Huge forces are needed to control them. Dipole magnets (2 poles) are used to bend the paths of the protons around the 27 km ring. Quadrupole magnets (4 poles) focus the proton beams and squeeze them so that more particles collide when the beams’ paths cross. There are 1232 15m long dipole magnets in the LHC.

  6. Preparation of positional renal slices for study of cell-specific toxicity.

    Science.gov (United States)

    Ruegg, C E; Gandolfi, A J; Nagle, R B; Krumdieck, C L; Brendel, K

    1987-04-01

    To reduce structural complexity, rabbit kidneys were sliced perpendicular to their cortical-papillary axis to isolate four distinct cell groupings. This positional orientation allows identification of each renal cell type based on its location within the slice. A mechanical slicer was used to make several precision-cut slices rapidly from an oriented cylindrical core of renal tissue, with minimal tissue trauma. Slices were then submerged under a gently circulating oxygenated media in a fritted glass support system that maintains viability (intracellular K+/DNA ratio) and structural integrity (histology) for at least 30 h. A high dose of mercuric chloride (10(-3) M) was used to demonstrate the structural and biochemical changes of intoxicated slices. This method provides a controlled subchronic in vitro system for the study of the individual cell types involved in cell-specific renal toxicities and may also be a useful tool for addressing other pharmacological and physiological research questions.

  7. “...those left behind.” Biology and Oncology of Invasive Glioma Cells

    Directory of Open Access Journals (Sweden)

    Michael E Berens

    1999-08-01

    Full Text Available Although significant technical advances in surgical and radiation treatment for brain tumors have emerged in recent years, their impact on clinical outcome for patients has been disappointing. A fundamental source of the management challenge presented by glioma patients is the insidious propensity of the malignant cells to invade into adjacent normal brain. Invasive tumor cells escape surgical removal and geographically dodge lethal radiation exposure. Recent improved understanding of the biochemistry and molecular determinants of glioma cell invasion provide valuable insight to the underlying biological features of the disease, as well as illuminating possible new therapeutic targets. Heightened commitment to migrate and invade is accompanied by a glioma cell's reduced proliferative activity. The microenvironmental manipulations coincident to invasion and migration may also impact the glioma cell's response to cytotoxic treatments. These collateral aspects of the glioma cell invasive phenotype should be further explored and exploited as novel antiglioma therapies.

  8. Microchromatographic study of hippocampal area CA3 proteins during prolonged post-tetanic potentiation in surviving slices

    International Nuclear Information System (INIS)

    Pankova, T.M.; Mikichur, N.I.; Ratushayak, A.S.; Shtark, M.B.

    1985-01-01

    This paper studies the synthesis of proteins and, in particular, of brain-specific proteins in a homogeneous population of postsynaptic cells during the development of prolonged post-tetanic potentiation (PPTP). By using a system of synaptic connections incorporation of tritium-leucine into water-soluble protein of this zone has been investigated during the development of PPTP (in surviving slices after stimulation of mossy fibers). During statistical analysis of the results mean values of deviation of relative radioactivity compared with the control in each fraction was expressed as a percentage. The results were analyzed by Student's test, at the 95% level of significance

  9. An overview of 5G network slicing architecture

    Science.gov (United States)

    Chen, Qiang; Wang, Xiaolei; Lv, Yingying

    2018-05-01

    With the development of mobile communication technology, the traditional single network model has been unable to meet the needs of users, and the demand for differentiated services is increasing. In order to solve this problem, the fifth generation of mobile communication technology came into being, and as one of the key technologies of 5G, network slice is the core technology of network virtualization and software defined network, enabling network slices to flexibly provide one or more network services according to users' needs[1]. Each slice can independently tailor the network functions according to the requirements of the business scene and the traffic model and manage the layout of the corresponding network resources, to improve the flexibility of network services and the utilization of resources, and enhance the robustness and reliability of the whole network [2].

  10. N-terminal pro-brain natriuretic peptide in relation to inflammation, myocardial necrosis, and the effect of an invasive strategy in unstable coronary artery disease.

    Science.gov (United States)

    Jernberg, Tomas; Lindahl, Bertil; Siegbahn, Agneta; Andren, Bertil; Frostfeldt, Gunnar; Lagerqvist, Bo; Stridsberg, Mats; Venge, Per; Wallentin, Lars

    2003-12-03

    We sought to examine whether measurements of N-terminal pro-brain natriuretic peptide (NT-proBNP), in addition to cardiac troponin T (cTnT) and interleukin-6 (IL-6), improve the ability to identify high-risk patients who benefit from an early invasive strategy. Biochemical indicators of cardiac performance (e.g., NT-proBNP), inflammation (e.g., IL-6), and myocardial damage (e.g., cTnT) predict mortality in unstable coronary artery disease (UCAD) (i.e., unstable angina or non-ST-segment elevation myocardial infarction [MI]). In these patients, an early invasive treatment strategy improves the outcome. Levels of NT-proBNP, cTnT, and IL-6 were measured in 2,019 patients with UCAD randomized to an invasive or non-invasive strategy in the FRagmin and fast revascularization during InStability in Coronary artery disease (FRISC-II) trial. Patients were followed up for two years to determine death and MI. Patients in the third NT-proBNP tertile had a 4.1-fold (95% confidence interval [CI] 2.4 to 7.2) and 3.5-fold (95% CI 1.8 to 6.8) increased mortality in the non-invasive and invasive groups, respectively. An increased NT-proBNP level was independently associated with mortality. In patients with increased levels of both NT-proBNP and IL-6, an early invasive strategy reduced mortality by 7.3% (risk ratio 0.46, 95% CI 0.21 to 1.00). In patients with lower NT-proBNP or IL-6 levels, the mortality was not reduced. Only elevated cTnT was independently associated with future MI and a reduction of MI by means of an invasive strategy. N-terminal proBNP is independently associated with mortality. The combination of NT-proBNP and IL-6 seems to be a useful tool in the identification of patients with a definite survival benefit from an early invasive strategy. Only cTnT is independently associated with future MI and a reduction of MI by an invasive strategy.

  11. A novel lung slice system with compromised antioxidant defenses

    Energy Technology Data Exchange (ETDEWEB)

    Hardwick, S.J.; Adam, A.; Cohen, G.M. (Univ. of London (England)); Smith, L.L. (Imperial Chemical Industries PLC, Cheshire (England))

    1990-04-01

    In order to facilitate the study of oxidative stress in lung tissue, rat lung slices with impaired antioxidant defenses were prepared and used. Incubation of lung slices with the antineoplastic agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) (100 {mu}M) in an amino acid-rich medium for 45 min produced a near-maximal (approximately 85%), irreversible inhibition of glutathione reductase, accompanied by only a modest (approximately 15%) decrease in pulmonary nonprotein sulfhydryls (NPSH) and no alteration in intracellular ATP, NADP{sup +}, and NADPH levels. The amounts of NADP(H), ATP, and NPSH were stable over a 4-hr incubation period following the removal from BCNU. The viability of the system was further evaluated by measuring the rate of evolution of {sup 14}CO{sub 2} from D-({sup 14}C(U))-glucose. The rates of evolution were almost identical in the compromised system when compared with control slices over a 4-hr time period. By using slices with compromised oxidative defenses, preliminary results have been obtained with paraquat, nitrofurantoin, and 2,3-dimethoxy-1,4-naphthoquinone.

  12. A novel lung slice system with compromised antioxidant defenses

    International Nuclear Information System (INIS)

    Hardwick, S.J.; Adam, A.; Cohen, G.M.; Smith, L.L.

    1990-01-01

    In order to facilitate the study of oxidative stress in lung tissue, rat lung slices with impaired antioxidant defenses were prepared and used. Incubation of lung slices with the antineoplastic agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) (100 μM) in an amino acid-rich medium for 45 min produced a near-maximal (approximately 85%), irreversible inhibition of glutathione reductase, accompanied by only a modest (approximately 15%) decrease in pulmonary nonprotein sulfhydryls (NPSH) and no alteration in intracellular ATP, NADP + , and NADPH levels. The amounts of NADP(H), ATP, and NPSH were stable over a 4-hr incubation period following the removal from BCNU. The viability of the system was further evaluated by measuring the rate of evolution of 14 CO 2 from D-[ 14 C(U)]-glucose. The rates of evolution were almost identical in the compromised system when compared with control slices over a 4-hr time period. By using slices with compromised oxidative defenses, preliminary results have been obtained with paraquat, nitrofurantoin, and 2,3-dimethoxy-1,4-naphthoquinone

  13. Mathematical modeling of human glioma growth based on brain topological structures: study of two clinical cases.

    Directory of Open Access Journals (Sweden)

    Cecilia Suarez

    Full Text Available Gliomas are the most common primary brain tumors and yet almost incurable due mainly to their great invasion capability. This represents a challenge to present clinical oncology. Here, we introduce a mathematical model aiming to improve tumor spreading capability definition. The model consists in a time dependent reaction-diffusion equation in a three-dimensional spatial domain that distinguishes between different brain topological structures. The model uses a series of digitized images from brain slices covering the whole human brain. The Talairach atlas included in the model describes brain structures at different levels. Also, the inclusion of the Brodmann areas allows prediction of the brain functions affected during tumor evolution and the estimation of correlated symptoms. The model is solved numerically using patient-specific parametrization and finite differences. Simulations consider an initial state with cellular proliferation alone (benign tumor, and an advanced state when infiltration starts (malign tumor. Survival time is estimated on the basis of tumor size and location. The model is used to predict tumor evolution in two clinical cases. In the first case, predictions show that real infiltrative areas are underestimated by current diagnostic imaging. In the second case, tumor spreading predictions were shown to be more accurate than those derived from previous models in the literature. Our results suggest that the inclusion of differential migration in glioma growth models constitutes another step towards a better prediction of tumor infiltration at the moment of surgical or radiosurgical target definition. Also, the addition of physiological/psychological considerations to classical anatomical models will provide a better and integral understanding of the patient disease at the moment of deciding therapeutic options, taking into account not only survival but also life quality.

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

    Science.gov (United States)

    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.

  15. Spatial Mapping of Protein Abundances in the Mouse Brain by Voxelation Integrated with High-Throughput Liquid Chromatography ? Mass Spectrometry

    International Nuclear Information System (INIS)

    Petyuk, Vladislav A.; Qian, Weijun; Chin, Mark H.; Wang, Haixing H.; Livesay, Eric A.; Monroe, Matthew E.; Adkins, Joshua N.; Jaitly, Navdeep; Anderson, David J.; Camp, David G.; Smith, Desmond J.; Smith, Richard D.

    2007-01-01

    Temporally and spatially resolved mapping of protein abundance patterns within the mammalian brain is of significant interest for understanding brain function and molecular etiologies of neurodegenerative diseases; however, such imaging efforts have been greatly challenged by complexity of the proteome, throughput and sensitivity of applied analytical methodologies, and accurate quantitation of protein abundances across the brain. Here, we describe a methodology for comprehensive spatial proteome mapping that addresses these challenges by employing voxelation integrated with automated microscale sample processing, high-throughput LC system coupled with high resolution Fourier transform ion cyclotron mass spectrometer and a ''universal'' stable isotope labeled reference sample approach for robust quantitation. We applied this methodology as a proof-of-concept trial for the analysis of protein distribution within a single coronal slice of a C57BL/6J mouse brain. For relative quantitation of the protein abundances across the slice, an 18O-isotopically labeled reference sample, derived from a whole control coronal slice from another mouse, was spiked into each voxel sample and stable isotopic intensity ratios were used to obtain measures of relative protein abundances. In total, we generated maps of protein abundance patterns for 1,028 proteins. The significant agreement of the protein distributions with previously reported data supports the validity of this methodology, which opens new opportunities for studying the spatial brain proteome and its dynamics during the course of disease progression and other important biological and associated health aspects in a discovery-driven fashion

  16. Non-iterative relative bias correction for 3D reconstruction of in utero fetal brain MR imaging.

    Science.gov (United States)

    Kim, Kio; Habas, Piotr; Rajagopalan, Vidya; Scott, Julia; Corbett-Detig, James; Rousseau, Francois; Glenn, Orit; Barkovich, James; Studholme, Colin

    2010-01-01

    The slice intersection motion correction (SIMC) method is a powerful tool to compensate for motion that occurs during in utero acquisition of the multislice magnetic resonance (MR) images of the human fetal brain. The SIMC method makes use of the slice intersection intensity profiles of orthogonally planned slice pairs to simultaneously correct for the relative motion occurring between all the acquired slices. This approach is based on the assumption that the bias field is consistent between slices. However, for some clinical studies where there is a strong bias field combined with significant fetal motion relative to the coils, this assumption is broken and the resulting motion estimate and the reconstruction to a 3D volume can both contain errors. In this work, we propose a method to correct for the relative differences in bias field between all slice pairs. For this, we define the energy function as the mean square difference of the intersection profiles, that is then minimized with respect to the bias field parameters of the slices. A non iterative method which considers the relative bias between each slice simultaneously is used to efficiently remove inconsistencies. The method, when tested on synthetic simulations and actual clinical imaging studies where bias was an issue, brought a significant improvement to the final reconstructed image.

  17. Gastric Metastasis of Triple Negative Invasive Lobular Carcinoma.

    Science.gov (United States)

    Geredeli, Caglayan; Dogru, Osman; Omeroglu, Ethem; Yilmaz, Farise; Cicekci, Faruk

    2015-05-05

    Invasive lobular carcinomas are the second most common type (5% to 15%) of invasive breast carcinomas. The most frequent sites of breast cancer metastasis are the local and distant lymph nodes, brain, lung, liver, and bones; metastasis to the gastrointestinal system, especially to the stomach, is rare. When a mass is detected in an unusual place in a patient with invasive lobular carcinoma, it should be kept in mind that such a mass may be either a second primary carcinoma or the metastasis of an invasive lobular carcinoma. In this report, we present a case of gastric metastasis from triple-negative invasive lobular breast cancer. It is important to make an accurate diagnosis by distinguishing gastric metastasis from breast cancer in order to select the best initial treatment for systemic diseases of breast cancer. Considering our case, healthcare professionals should take into account that cases with invasive lobular breast cancer may experience unusual metastases.

  18. Equilibrium initial data for moving puncture simulations: the stationary 1 + log slicing

    International Nuclear Information System (INIS)

    Baumgarte, T W; Matera, K; Etienne, Z B; Liu, Y T; Shapiro, S L; Taniguchi, K; Murchadha, N O

    2009-01-01

    We discuss a 'stationary 1 + log' slicing condition for the construction of solutions to Einstein's constraint equations. For stationary spacetimes, these initial data give a stationary foliation when evolved with 'moving puncture' gauge conditions that are often used in black hole evolutions. The resulting slicing is time independent and agrees with the slicing generated by being dragged along a timelike Killing vector of the spacetime. When these initial data are evolved with moving puncture gauge conditions, numerical errors arising from coordinate evolution should be minimized. While these properties appear very promising, suggesting that this slicing condition should be an attractive alternative to, for example, maximal slicing, we demonstrate in this paper that solutions can be constructed only for a small class of problems. For binary black hole initial data, in particular, it is often assumed that there exists an approximate helical Killing vector that generates the binary's orbit. We show that 1 + log slices that are stationary with respect to such a helical Killing vector cannot be asymptotically flat, unless the spacetime possesses an additional axial Killing vector.

  19. Electron slicing for the generation of tunable femtosecond soft x-ray pulses from a free electron laser and slice diagnostics

    Directory of Open Access Journals (Sweden)

    S. Di Mitri

    2013-04-01

    Full Text Available We present the experimental results of femtosecond slicing an ultrarelativistic, high brightness electron beam with a collimator. In contrast to some qualitative considerations reported in Phys. Rev. Lett. 92, 074801 (2004PRLTAO0031-900710.1103/PhysRevLett.92.074801, we first demonstrate that the collimation process preserves the slice beam quality, in agreement with our theoretical expectations, and that the collimation is compatible with the operation of a linear accelerator in terms of beam transport, radiation dose, and collimator heating. Accordingly, the collimated beam can be used for the generation of stable femtosecond soft x-ray pulses of tunable duration, from either a self-amplified spontaneous emission or an externally seeded free electron laser. The proposed method also turns out to be a more compact and cheaper solution for electron slice diagnostics than the commonly used radio frequency deflecting cavities and has minimal impact on the machine design.

  20. Non-invasive neural stimulation

    Science.gov (United States)

    Tyler, William J.; Sanguinetti, Joseph L.; Fini, Maria; Hool, Nicholas

    2017-05-01

    Neurotechnologies for non-invasively interfacing with neural circuits have been evolving from those capable of sensing neural activity to those capable of restoring and enhancing human brain function. Generally referred to as non-invasive neural stimulation (NINS) methods, these neuromodulation approaches rely on electrical, magnetic, photonic, and acoustic or ultrasonic energy to influence nervous system activity, brain function, and behavior. Evidence that has been surmounting for decades shows that advanced neural engineering of NINS technologies will indeed transform the way humans treat diseases, interact with information, communicate, and learn. The physics underlying the ability of various NINS methods to modulate nervous system activity can be quite different from one another depending on the energy modality used as we briefly discuss. For members of commercial and defense industry sectors that have not traditionally engaged in neuroscience research and development, the science, engineering and technology required to advance NINS methods beyond the state-of-the-art presents tremendous opportunities. Within the past few years alone there have been large increases in global investments made by federal agencies, foundations, private investors and multinational corporations to develop advanced applications of NINS technologies. Driven by these efforts NINS methods and devices have recently been introduced to mass markets via the consumer electronics industry. Further, NINS continues to be explored in a growing number of defense applications focused on enhancing human dimensions. The present paper provides a brief introduction to the field of non-invasive neural stimulation by highlighting some of the more common methods in use or under current development today.

  1. (Non)perturbative gravity, nonlocality, and nice slices

    International Nuclear Information System (INIS)

    Giddings, Steven B.

    2006-01-01

    Perturbative dynamics of gravity is investigated for high-energy scattering and in black hole backgrounds. In the latter case, a straightforward perturbative analysis fails, in a close parallel to the failure of the former when the impact parameter reaches the Schwarzschild radius. This suggests a flaw in a semiclassical description of physics on spatial slices that intersect both outgoing Hawking radiation and matter that has carried information into a black hole; such slices are instrumental in a general argument for black hole information loss. This indicates a possible role for the proposal that nonperturbative gravitational physics is intrinsically nonlocal

  2. The clinical efficacy of 1 mm-slice CT of the middle ear

    International Nuclear Information System (INIS)

    Noda, Kazuhiro; Noiri, Teruhisa; Doi, Katsumi; Koizuka, Izumi; Tanaka, Hisashi; Mishiro, Yasuo; Okumura, Shin-ichi; Kubo, Takeshi

    2000-01-01

    The efficacy of the preoperative 1 mm-slice CT for evaluating the condition of the ossicular chain and the facial canal was assessed. CT findings were compared with the operative findings of middle ears in 120 cases of chronic otitis media or cholesteatoma that underwent tympanoplasty. The reliability of 1 mm-slice CT in detecting any defect of the ossicular chain was much superior to those of 2 mm-slice CT previously reported, and the difference between them is essential for preoperative information. On the other hand, thinner slice than 1 mm may be unnecessary, especially in routine use. (author)

  3. The clinical efficacy of 1 mm-slice CT of the middle ear

    Energy Technology Data Exchange (ETDEWEB)

    Noda, Kazuhiro; Noiri, Teruhisa [Kawanishi Municipal Hospital, Hyogo (Japan); Doi, Katsumi; Koizuka, Izumi; Tanaka, Hisashi; Mishiro, Yasuo; Okumura, Shin-ichi; Kubo, Takeshi

    2000-02-01

    The efficacy of the preoperative 1 mm-slice CT for evaluating the condition of the ossicular chain and the facial canal was assessed. CT findings were compared with the operative findings of middle ears in 120 cases of chronic otitis media or cholesteatoma that underwent tympanoplasty. The reliability of 1 mm-slice CT in detecting any defect of the ossicular chain was much superior to those of 2 mm-slice CT previously reported, and the difference between them is essential for preoperative information. On the other hand, thinner slice than 1 mm may be unnecessary, especially in routine use. (author)

  4. CT coronary angiography vs. invasive coronary angiography in CHD

    Directory of Open Access Journals (Sweden)

    Anja Hagen

    2012-04-01

    Full Text Available Scientific background: Various diagnostic tests including conventional invasive coronary angiography and non-invasive computed tomography (CT coronary angiography are used in the diagnosis of coronary heart disease (CHD. Research questions: The present report aims to evaluate the clinical efficacy, diagnostic accuracy, prognostic value cost-effectiveness as well as the ethical, social and legal implications of CT coronary angiography versus invasive coronary angiography in the diagnosis of CHD. Methods: A systematic literature search was conducted in electronic data bases (MEDLINE, EMBASE etc. in October 2010 and was completed with a manual search. The literature search was restricted to articles published from 2006 in German or English. Two independent reviewers were involved in the selection of the relevant publications. The medical evaluation was based on systematic reviews of diagnostic studies with invasive coronary angiography as the reference standard and on diagnostic studies with intracoronary pressure measurement as the reference standard. Study results were combined in a meta-analysis with 95 % confidence intervals (CI. Additionally, data on radiation doses from current non-systematic reviews were taken into account. A health economic evaluation was performed by modelling from the social perspective with clinical assumptions derived from the meta-analysis and economic assumptions derived from contemporary German sources. Data on special indications (bypass or in-stent-restenosis were not included in the evaluation. Only data obtained using CT scanners with at least 64 slices were considered. Results: No studies were found regarding the clinical efficacy or prognostic value of CT coronary angiography versus conventional invasive coronary angiography in the diagnosis of CHD. Overall, 15 systematic reviews with data from 44 diagnostic studies using invasive coronary angiography as the reference standard (identification of obstructive

  5. Brain-Computer Interfaces Revolutionizing Human-Computer Interaction

    CERN Document Server

    Graimann, Bernhard; Allison, Brendan

    2010-01-01

    A brain-computer interface (BCI) establishes a direct output channel between the human brain and external devices. BCIs infer user intent via direct measures of brain activity and thus enable communication and control without movement. This book, authored by experts in the field, provides an accessible introduction to the neurophysiological and signal-processing background required for BCI, presents state-of-the-art non-invasive and invasive approaches, gives an overview of current hardware and software solutions, and reviews the most interesting as well as new, emerging BCI applications. The book is intended not only for students and young researchers, but also for newcomers and other readers from diverse backgrounds keen to learn about this vital scientific endeavour.

  6. Slice through an LHC focusing magnet

    CERN Multimedia

    Slice through an LHC superconducting quadrupole (focusing) magnet. The slice includes a cut through the magnet wiring (niobium titanium), the beampipe and the steel magnet yokes. Particle beams in the Large Hadron Collider (LHC) have the same energy as a high-speed train, squeezed ready for collision into a space narrower than a human hair. Huge forces are needed to control them. Dipole magnets (2 poles) are used to bend the paths of the protons around the 27 km ring. Quadrupole magnets (4 poles) focus the proton beams and squeeze them so that more particles collide when the beams’ paths cross. Bringing beams into collision requires a precision comparable to making two knitting needles collide, launched from either side of the Atlantic Ocean.

  7. Mechanisms of Glioma Formation: Iterative Perivascular Glioma Growth and Invasion Leads to Tumor Progression, VEGF-Independent Vascularization, and Resistance to Antiangiogenic Therapy

    Directory of Open Access Journals (Sweden)

    Gregory J. Baker

    2014-07-01

    Full Text Available As glioma cells infiltrate the brain they become associated with various microanatomic brain structures such as blood vessels, white matter tracts, and brain parenchyma. How these distinct invasion patterns coordinate tumor growth and influence clinical outcomes remain poorly understood. We have investigated how perivascular growth affects glioma growth patterning and response to antiangiogenic therapy within the highly vascularized brain. Orthotopically implanted rodent and human glioma cells are shown to commonly invade and proliferate within brain perivascular space. This form of brain tumor growth and invasion is also shown to characterize de novo generated endogenous mouse brain tumors, biopsies of primary human glioblastoma (GBM, and peripheral cancer metastasis to the human brain. Perivascularly invading brain tumors become vascularized by normal brain microvessels as individual glioma cells use perivascular space as a conduit for tumor invasion. Agent-based computational modeling recapitulated biological perivascular glioma growth without the need for neoangiogenesis. We tested the requirement for neoangiogenesis in perivascular glioma by treating animals with angiogenesis inhibitors bevacizumab and DC101. These inhibitors induced the expected vessel normalization, yet failed to reduce tumor growth or improve survival of mice bearing orthotopic or endogenous gliomas while exacerbating brain tumor invasion. Our results provide compelling experimental evidence in support of the recently described failure of clinically used antiangiogenics to extend the overall survival of human GBM patients.

  8. Feasibility study of 2D thick-slice MR digital subtraction angiography

    International Nuclear Information System (INIS)

    Ishimori, Yoshiyuki; Takeuchi, Miho; Higashimura, Kyouji; Komuro, Hiroyuki

    2000-01-01

    Conditions required to perform contrast MR digital subtraction angiography using a two-dimensional thick-slice high-speed gradient echo were investigated. The conditions in the phantom experiment included: slice profile, flip angle, imaging matrix, fat suppression, duration of IR pulse and frequency selectivity, flip angle of IR pulse and inversion time. Based on the results of the experiment, 2D thick-slice MRDSA was performed in volunteers. Under TR/TE=5.3-9/1.3-1.8 ms conditions, the requirements were a slice thick enough to include the target region, a flip angle of 10 degrees, and a phase matrix of 96 or more. Fat suppression was required for adipose-tissue-rich regions, such as the abdomen. The optimal conditions for applying the IR preparation pulse of the IR prepped fast gradient recalled echo as spectrally selective inversion recovery appeared to be: duration of IR pulse =20 ms, flip angle =100 degrees, and inversion time =40 ms. The authors concluded that it was feasible to perform 2D thick-slice MRDSA with time resolution within 1 second. (K.H.)

  9. Free-breathing cardiac MR stress perfusion with real-time slice tracking.

    Science.gov (United States)

    Basha, Tamer A; Roujol, Sébastien; Kissinger, Kraig V; Goddu, Beth; Berg, Sophie; Manning, Warren J; Nezafat, Reza

    2014-09-01

    To develop a free-breathing cardiac MR perfusion sequence with slice tracking for use after physical exercise. We propose to use a leading navigator, placed immediately before each 2D slice acquisition, for tracking the respiratory motion and updating the slice location in real-time. The proposed sequence was used to acquire CMR perfusion datasets in 12 healthy adult subjects and 8 patients. Images were compared with the conventional perfusion (i.e., without slice tracking) results from the same subjects. The location and geometry of the myocardium were quantitatively analyzed, and the perfusion signal curves were calculated from both sequences to show the efficacy of the proposed sequence. The proposed sequence was significantly better compared with the conventional perfusion sequence in terms of qualitative image scores. Changes in the myocardial location and geometry decreased by 50% in the slice tracking sequence. Furthermore, the proposed sequence had signal curves that are smoother and less noisy. The proposed sequence significantly reduces the effect of the respiratory motion on the image acquisition in both rest and stress perfusion scans. Copyright © 2013 Wiley Periodicals, Inc.

  10. Study of Energy Consumption of Potato Slices During Drying Process

    Directory of Open Access Journals (Sweden)

    Hafezi Negar

    2015-06-01

    Full Text Available One of the new methods of food drying using infrared heating under vacuum is to increase the drying rate and maintain the quality of dried product. In this study, potato slices were dried using vacuum-infrared drying. Experiments were performed with the infrared lamp power levels 100, 150 and 200 W, absolute pressure levels 20, 80, 140 and 760 mmHg, and with three thicknesses of slices 1, 2 and 3 mm, in three repetitions. The results showed that the infrared lamp power, absolute pressure and slice thickness have important effects on the drying of potato. With increasing the radiation power, reducing the absolute pressure (acts of vacuum in the dryer chamber and also reducing the thickness of potato slices, drying time and the amount of energy consumed is reduced. In relation to thermal utilization efficiency, results indicated that with increasing the infrared radiation power and decreasing the absolute pressure, thermal efficiency increased.

  11. 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.

  12. Techniques for Non-Invasive Monitoring of Arterial Blood Pressure

    Directory of Open Access Journals (Sweden)

    Agnes S. Meidert

    2018-01-01

    Full Text Available Since both, hypotension and hypertension, can potentially impair the function of vital organs such as heart, brain, or kidneys, monitoring of arterial blood pressure (BP is a mainstay of hemodynamic monitoring in acutely or critically ill patients. Arterial BP can either be obtained invasively via an arterial catheter or non-invasively. Non-invasive BP measurement provides either intermittent or continuous readings. Most commonly, an occluding upper arm cuff is used for intermittent non-invasive monitoring. BP values are then obtained either manually (by auscultation of Korotkoff sounds or palpation or automatically (e.g., by oscillometry. For continuous non-invasive BP monitoring, the volume clamp method or arterial applanation tonometry can be used. Both techniques enable the arterial waveform and BP values to be obtained continuously. This article describes the different techniques for non-invasive BP measurement, their advantages and limitations, and their clinical applicability.

  13. Excitatory and inhibitory pathways modulate kainate excitotoxicity in hippocampal slice cultures

    DEFF Research Database (Denmark)

    Casaccia-Bonnefil, P; Benedikz, Eirikur; Rai, R

    1993-01-01

    In organotypic hippocampal slice cultures, kainate (KA) specifically induces cell loss in the CA3 region while N-methyl-D-aspartate induces cell loss in the CA1 region. The sensitivity of slice cultures to KA toxicity appears only after 2 weeks in vitro which parallels the appearance of mossy...... fibers. KA toxicity is potentiated by co-application with the GABA-A antagonist, picrotoxin. These data suggest that the excitotoxicity of KA in slice cultures is modulated by both excitatory and inhibitory synapses....

  14. Sixty-four slice spiral CT angiography does not predict the functional relevance of coronary artery stenoses in patients with stable angina

    International Nuclear Information System (INIS)

    Hacker, Marcus; Hack, Nicolas; Hahn, Klaus; Tiling, Reinhold; Jakobs, Tobias; Nikolaou, Konstantin; Becker, Christoph; Reiser, Maximilian; Ziegler, Franz von; Knez, Andreas; Koenig, Andreas; Klauss, Volker

    2007-01-01

    The aim of this study was to evaluate spiral multidetector computed tomography (MDCT) angiography using 64-slice technique in the detection of functionally relevant coronary artery stenoses (CAS). Thirty-eight patients (62±11 years, 28 men) with stable angina (26 with suspected and 12 with known coronary artery disease) were investigated using 64-slice MDCT angiography and gated myocardial perfusion SPECT (gated SPECT); a subgroup of 30 patients had additional invasive coronary angiography (ICA). Stenoses with luminal narrowing of ≥50% were defined as ''significant'' in MDCT angiography and ICA. MDCT angiography was compared with gated SPECT and the combination of gated SPECT plus ICA with respect to the detection of functionally relevant CAS. The sensitivity, specificity and negative and positive predictive values of MDCT angiography in detecting reversible perfusion defects on gated SPECT were 63%, 80%, 94% and 32%, respectively, in vessel-based analysis and 71%, 62%, 72% and 60%, respectively, in patient-based analysis. If only reversible perfusion defects on gated SPECT with CAS ≥50% on ICA were considered, the sensitivity, specificity and negative and positive predictive values were, respectively, 85%, 79%, 98% and 33% for vessel-based analysis and 85%, 59%, 83% and 61% for patient-based analysis. Sixty-four slice MDCT angiography failed to predict the functional relevance of CAS, but had a high negative predictive value in the exclusion of functionally relevant CAS in symptomatic patients. (orig.)

  15. Sixty-four slice spiral CT angiography does not predict the functional relevance of coronary artery stenoses in patients with stable angina

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, Marcus; Hack, Nicolas; Hahn, Klaus; Tiling, Reinhold [Ludwig-Maximilians-University, Department of Nuclear Medicine, Munich (Germany); Jakobs, Tobias; Nikolaou, Konstantin; Becker, Christoph; Reiser, Maximilian [Ludwig-Maximilians-University, Department of Clinical Radiology, Munich (Germany); Ziegler, Franz von; Knez, Andreas [Ludwig-Maximilians-University, Department of Cardiology, Klinikum Grosshadern, Munich (Germany); Koenig, Andreas; Klauss, Volker [Ludwig-Maximilians-University, Department of Cardiology, Medizinische Poliklinik-Innenstadt, Munich (Germany)

    2007-01-15

    The aim of this study was to evaluate spiral multidetector computed tomography (MDCT) angiography using 64-slice technique in the detection of functionally relevant coronary artery stenoses (CAS). Thirty-eight patients (62{+-}11 years, 28 men) with stable angina (26 with suspected and 12 with known coronary artery disease) were investigated using 64-slice MDCT angiography and gated myocardial perfusion SPECT (gated SPECT); a subgroup of 30 patients had additional invasive coronary angiography (ICA). Stenoses with luminal narrowing of {>=}50% were defined as ''significant'' in MDCT angiography and ICA. MDCT angiography was compared with gated SPECT and the combination of gated SPECT plus ICA with respect to the detection of functionally relevant CAS. The sensitivity, specificity and negative and positive predictive values of MDCT angiography in detecting reversible perfusion defects on gated SPECT were 63%, 80%, 94% and 32%, respectively, in vessel-based analysis and 71%, 62%, 72% and 60%, respectively, in patient-based analysis. If only reversible perfusion defects on gated SPECT with CAS {>=}50% on ICA were considered, the sensitivity, specificity and negative and positive predictive values were, respectively, 85%, 79%, 98% and 33% for vessel-based analysis and 85%, 59%, 83% and 61% for patient-based analysis. Sixty-four slice MDCT angiography failed to predict the functional relevance of CAS, but had a high negative predictive value in the exclusion of functionally relevant CAS in symptomatic patients. (orig.)

  16. Cochlear Implant Electrode Localization Using an Ultra-High Resolution Scan Mode on Conventional 64-Slice and New Generation 192-Slice Multi-Detector Computed Tomography.

    Science.gov (United States)

    Carlson, Matthew L; Leng, Shuai; Diehn, Felix E; Witte, Robert J; Krecke, Karl N; Grimes, Josh; Koeller, Kelly K; Bruesewitz, Michael R; McCollough, Cynthia H; Lane, John I

    2017-08-01

    A new generation 192-slice multi-detector computed tomography (MDCT) clinical scanner provides enhanced image quality and superior electrode localization over conventional MDCT. Currently, accurate and reliable cochlear implant electrode localization using conventional MDCT scanners remains elusive. Eight fresh-frozen cadaveric temporal bones were implanted with full-length cochlear implant electrodes. Specimens were subsequently scanned with conventional 64-slice and new generation 192-slice MDCT scanners utilizing ultra-high resolution modes. Additionally, all specimens were scanned with micro-CT to provide a reference criterion for electrode position. Images were reconstructed according to routine temporal bone clinical protocols. Three neuroradiologists, blinded to scanner type, reviewed images independently to assess resolution of individual electrodes, scalar localization, and severity of image artifact. Serving as the reference standard, micro-CT identified scalar crossover in one specimen; imaging of all remaining cochleae demonstrated complete scala tympani insertions. The 192-slice MDCT scanner exhibited improved resolution of individual electrodes (p implant imaging compared with conventional MDCT. This technology provides important feedback regarding electrode position and course, which may help in future optimization of surgical technique and electrode design.

  17. The visibility of mandibular canal on orthoradial and oblique CBCT slices at molar implant sites

    International Nuclear Information System (INIS)

    Alkhader, Mustafa; Jarab, Fadi; Shaweesh, Ashraf; Hudieb, Malik

    2016-01-01

    The aim of the present study was to compare visibility of the mandibular canal on cone beam computed tomography (CBCT)-based orthoradial and oblique slices at molar implant sites. CBCT images for 132 mandibular molar implant sites were selected for the study. After generating orthoradial and oblique slices, two observers evaluated the visibility of the mandibular canal using three-point scoring scale (1-3, good to excellent). Wilcoxon signed-rank test compared the visibility scores of the two slices. Both orthoradial and oblique slices obtained from CBCT had only very good to excellent mandibular canal visibility scores. At 114 mandibular molar implant sites, the visibility score was equal on both orthoradial and oblique slices. Although the visibility score was higher on orthoradial slices for 12 implant sites, the visibility score was higher for six implant sites on oblique slices and the difference was not significant. Therefore, the visibility of the mandibular canal was excellent and comparable on most of orthoradial and oblique slices obtained from CBCT images

  18. Conversion of Synthetic Aβ to In Vivo Active Seeds and Amyloid Plaque Formation in a Hippocampal Slice Culture Model.

    Science.gov (United States)

    Novotny, Renata; Langer, Franziska; Mahler, Jasmin; Skodras, Angelos; Vlachos, Andreas; Wegenast-Braun, Bettina M; Kaeser, Stephan A; Neher, Jonas J; Eisele, Yvonne S; Pietrowski, Marie J; Nilsson, K Peter R; Deller, Thomas; Staufenbiel, Matthias; Heimrich, Bernd; Jucker, Mathias

    2016-05-04

    The aggregation of amyloid-β peptide (Aβ) in brain is an early event and hallmark of Alzheimer's disease (AD). We combined the advantages of in vitro and in vivo approaches to study cerebral β-amyloidosis by establishing a long-term hippocampal slice culture (HSC) model. While no Aβ deposition was noted in untreated HSCs of postnatal Aβ precursor protein transgenic (APP tg) mice, Aβ deposition emerged in HSCs when cultures were treated once with brain extract from aged APP tg mice and the culture medium was continuously supplemented with synthetic Aβ. Seeded Aβ deposition was also observed under the same conditions in HSCs derived from wild-type or App-null mice but in no comparable way when HSCs were fixed before cultivation. Both the nature of the brain extract and the synthetic Aβ species determined the conformational characteristics of HSC Aβ deposition. HSC Aβ deposits induced a microglia response, spine loss, and neuritic dystrophy but no obvious neuron loss. Remarkably, in contrast to in vitro aggregated synthetic Aβ, homogenates of Aβ deposits containing HSCs induced cerebral β-amyloidosis upon intracerebral inoculation into young APP tg mice. Our results demonstrate that a living cellular environment promotes the seeded conversion of synthetic Aβ into a potent in vivo seeding-active form. In this study, we report the seeded induction of Aβ aggregation and deposition in long-term hippocampal slice cultures. Remarkably, we find that the biological activities of the largely synthetic Aβ aggregates in the culture are very similar to those observed in vivo This observation is the first to show that potent in vivo seeding-active Aβ aggregates can be obtained by seeded conversion of synthetic Aβ in a living (wild-type) cellular environment. Copyright © 2016 the authors 0270-6474/16/365084-10$15.00/0.

  19. Magnetohydrodynamics of unsteady viscous fluid on boundary layer past a sliced sphere

    Science.gov (United States)

    Nursalim, Rahmat; Widodo, Basuki; Imron, Chairul

    2017-10-01

    Magnetohydrodynamics (MHD) is important study in engineering and industrial fields. By study on MHD, we can reach the fluid flow characteristics that can be used to minimize its negative effect to an object. In decades, MHD has been widely studied in various geometry forms and fluid types. The sliced sphere is a geometry form that has not been investigated. In this paper we study magnetohydrodynamics of unsteady viscous fluid on boundary layer past a sliced sphere. Assumed that the fluid is incompressible, there is no magnetic field, there is no electrical voltage, the sliced sphere is fix and there is no barrier around the object. In this paper we focus on velocity profile at stagnation point (x = 0°). Mathematical model is governed by continuity and momentum equation. It is converted to non-dimensional, stream function, and similarity equation. Solution of the mathematical model is obtained by using Keller-Box numerical method. By giving various of slicing angle and various of magnetic parameter we get the simulation results. The simulation results show that increasing the slicing angle causes the velocity profile be steeper. Also, increasing the value of magnetic parameter causes the velocity profile be steeper. On the large slicing angle there is no significant effect of magnetic parameter to velocity profile, and on the high the value of magnetic parameter there is no significant effect of slicing angle to velocity profile.

  20. On the way to isotopic spatial resolution: technical principles and applications of 16-slice CT

    International Nuclear Information System (INIS)

    Flohr, T.; Ohnesorge, B.; Stierstorfer, K.

    2005-01-01

    The broad introduction of multi-slice CT by all major vendors in 1998 was a milestone with regard to extended volume coverage, improved axial resolution and better utilization of the tube output. New clinical applications such as CT-examinations of the heart and the coronary arteries became possible. Despite all promising advances, some limitations remain for 4-slice CT systems. They come close to isotropic resolution, but do not fully reach it in routine clinical applications. Cardiac CT-examinations require careful patient selection. The new generation of multi-slice CT-systems offer simultaneous acquisition of up to 16 sub-millimeter slices and improved temporal resolution for cardiac examinations by means of reduced gantry rotation time (0.4 s). In this overview article we present the basic technical principles and potential applications of 16-slice technology for the example of a 16-slice CT-system (SOMATOM Sensation 16, Siemens AG, Forchheim). We discuss detector design and dose efficiency as well as spiral scan- and reconstruction techniques. At comparable slice thickness, 16-slice CT-systems have a better dose efficiency than 4-slice CT-systems. The cone-beam geometry of the measurement rays requires new reconstruction approaches, an example is the adaptive multiple plane reconstruction, AMPR. First clinical experience indicates that sub-millimeter slice width in combination with reduced gantry rotation-time improves the clinical stability of cardiac examinations and expands the spectrum of patients accessible to cardiac CT. 16-slice CT-systems have the potential to cover even large scan ranges with sub-millimeter slices at considerably reduced examination times, thus approaching the goal of routine isotropic imaging [de

  1. D-BRAIN : Anatomically accurate simulated diffusion MRI brain data

    NARCIS (Netherlands)

    Perrone, Daniele; Jeurissen, Ben; Aelterman, Jan; Roine, Timo; Sijbers, Jan; Pizurica, Aleksandra; Leemans, Alexander; Philips, Wilfried

    2016-01-01

    Diffusion Weighted (DW) MRI allows for the non-invasive study of water diffusion inside living tissues. As such, it is useful for the investigation of human brain white matter (WM) connectivity in vivo through fiber tractography (FT) algorithms. Many DW-MRI tailored restoration techniques and FT

  2. Brain morphology imaging by 3D microscopy and fluorescent Nissl staining.

    Science.gov (United States)

    Lazutkin, A A; Komissarova, N V; Toptunov, D M; Anokhin, K V

    2013-07-01

    Modern optical methods (multiphoton and light-sheet fluorescent microscopy) allow 3D imaging of large specimens of the brain with cell resolution. It is therefore essential to refer the resultant 3D pictures of expression of transgene, protein, and other markers in the brain to the corresponding structures in the atlas. This implies counterstaining of specimens with morphological dyes. However, there are no methods for contrasting large samples of the brain without their preliminary slicing. We have developed a method for fluorescent Nissl staining of whole brain samples. 3D reconstructions of specimens of the hippocampus, olfactory bulbs, and cortex were created. The method can be used for morphological control and evaluation of the effects of various factors on the brain using 3D microscopy technique.

  3. MR image-guided portal verification for brain treatment field

    International Nuclear Information System (INIS)

    Yin Fangfang; Gao Qinghuai; Xie Huchen; Nelson, Diana F.; Yu Yan; Kwok, W. Edmund; Totterman, Saara; Schell, Michael C.; Rubin, Philip

    1998-01-01

    Purpose: To investigate a method for the generation of digitally reconstructed radiographs directly from MR images (DRR-MRI) to guide a computerized portal verification procedure. Methods and Materials: Several major steps were developed to perform an MR image-guided portal verification procedure. Initially, a wavelet-based multiresolution adaptive thresholding method was used to segment the skin slice-by-slice in MR brain axial images. Some selected anatomical structures, such as target volume and critical organs, were then manually identified and were reassigned to relatively higher intensities. Interslice information was interpolated with a directional method to achieve comparable display resolution in three dimensions. Next, a ray-tracing method was used to generate a DRR-MRI image at the planned treatment position, and the ray tracing was simply performed on summation of voxels along the ray. The skin and its relative positions were also projected to the DRR-MRI and were used to guide the search of similar features in the portal image. A Canny edge detector was used to enhance the brain contour in both portal and simulation images. The skin in the brain portal image was then extracted using a knowledge-based searching technique. Finally, a Chamfer matching technique was used to correlate features between DRR-MRI and portal image. Results: The MR image-guided portal verification method was evaluated using a brain phantom case and a clinical patient case. Both DRR-CT and DRR-MRI were generated using CT and MR phantom images with the same beam orientation and then compared. The matching result indicated that the maximum deviation of internal structures was less than 1 mm. The segmented results for brain MR slice images indicated that a wavelet-based image segmentation technique provided a reasonable estimation for the brain skin. For the clinical patient case with a given portal field, the MR image-guided verification method provided an excellent match between

  4. [Standardization of production of process Notopterygii Rhizoma et Radix slices].

    Science.gov (United States)

    Sun, Zhen-Yang; Wang, Ying-Zi; Nie, Rui-Jie; Zhang, Jing-Zhen; Wang, Si-Yu

    2017-12-01

    Notopterol, isoimperatorin, volatile oil and extract (water and ethanol) were used as the research objects in this study to investigate the effects of different softening method, slice thickness and drying methods on the quality of Notopterygii Rhizoma et Radix slices, and the experimental data were analyzed by homogeneous distance evaluation method. The results showed that different softening, cutting and drying processes could affect the content of five components in Notopterygii Rhizoma et Radix incisum. The best processing technology of Notopterygii Rhizoma et Radix slices was as follows: non-medicinal parts were removed; mildewed and rot as well as moth-eaten parts were removed; washed by the flowing drinking water; stacked in the drug pool; moistening method was used for softening, where 1/8 volume of water was sprayed for every 1 kg of herbs every 2 h; upper part of herbs covered with clean and moist cotton, and cut into thick slices (2-4 mm) after 12 h moistening until appropriate softness, then received blast drying for 4 h at 50 ℃, and turned over for 2 times during the drying. The process is practical and provides the experimental basis for the standardization of the processing of Notopterygii Rhizoma et Radix, with great significance to improve the quality of Notopterygii Rhizoma et Radix slices. Copyright© by the Chinese Pharmaceutical Association.

  5. Distributing coil elements in three dimensions enhances parallel transmission multiband RF performance: A simulation study in the human brain at 7 Tesla.

    Science.gov (United States)

    Wu, Xiaoping; Tian, Jinfeng; Schmitter, Sebastian; Vaughan, J Tommy; Uğurbil, Kâmil; Van de Moortele, Pierre-François

    2016-06-01

    We explore the advantages of using a double-ring radiofrequency (RF) array and slice orientation to design parallel transmission (pTx) multiband (MB) pulses for simultaneous multislice (SMS) imaging with whole-brain coverage at 7 Tesla (T). A double-ring head array with 16 elements split evenly in two rings stacked in the z-direction was modeled and compared with two single-ring arrays consisting of 8 or 16 elements. The array performance was evaluated by designing band-specific pTx MB pulses with local specific absorption rate (SAR) control. The impact of slice orientations was also investigated. The double-ring array consistently and significantly outperformed the other two single-ring arrays, with peak local SAR reduced by up to 40% at a fixed excitation error of 0.024. For all three arrays, exciting sagittal or coronal slices yielded better RF performance than exciting axial or oblique slices. A double-ring RF array can be used to drastically improve SAR versus excitation fidelity tradeoff for pTx MB pulse design for brain imaging at 7 T; therefore, it is preferable against single-ring RF array designs when pursuing various biomedical applications of pTx SMS imaging. In comparing the stripline arrays, coronal and sagittal slices are more advantageous than axial and oblique slices for pTx MB pulses. Magn Reson Med 75:2464-2472, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  6. Slice image pretreatment for cone-beam computed tomography based on adaptive filter

    International Nuclear Information System (INIS)

    Huang Kuidong; Zhang Dinghua; Jin Yanfang

    2009-01-01

    According to the noise properties and the serial slice image characteristics in Cone-Beam Computed Tomography (CBCT) system, a slice image pretreatment for CBCT based on adaptive filter was proposed. The judging criterion for the noise is established firstly. All pixels are classified into two classes: adaptive center weighted modified trimmed mean (ACWMTM) filter is used for the pixels corrupted by Gauss noise and adaptive median (AM) filter is used for the pixels corrupted by impulse noise. In ACWMTM filtering algorithm, the estimated Gauss noise standard deviation in the current slice image with offset window is replaced by the estimated standard deviation in the adjacent slice image to the current with the corresponding window, so the filtering accuracy of the serial images is improved. The pretreatment experiment on CBCT slice images of wax model of hollow turbine blade shows that the method makes a good performance both on eliminating noises and on protecting details. (authors)

  7. Brain imaging during seizure: ictal brain SPECT

    International Nuclear Information System (INIS)

    Kottamasu, Sambasiva Rao

    1997-01-01

    The role of single photon computed tomography (SPECT) in presurgical localization of medically intractable complex partial epilepsy (CPE) in children is reviewed. 99m Technetium neurolite, a newer lipophylic agent with a high first pass brain extraction and little or no redistribution is injected during a seizure, while the child is monitored with a video recording and continuous EEG and SPECT imaging is performed in the next 1-3 hours with the images representing regional cerebral profusion at the time of injection. On SPECT studies performed with radiopharmaceutical injected during a seizure, ictal focus is generally hypervascular. Other findings on ictal brain SPECT include hypoperfusion of adjacent cerebral cortex and white matter, hyperperfusion of contralateral motor cortex, hyperperfusion of ipsilateral basal ganglia and thalamus, brain stem and contralateral cerebellum. Ictal brain SPECT is non-invasive, cost effective and highly sensitive for localization of epileptic focus in patients with intractable CPE. (author)

  8. Drying characteristics of pumpkin ( Cucurbita moschata) slices in convective and freeze dryer

    Science.gov (United States)

    Caliskan, Gulsah; Dirim, Safiye Nur

    2017-06-01

    This study was intended to determine the drying and rehydration kinetics of convective and freeze dried pumpkin slices (0.5 × 3.5 × 0.5 cm). A pilot scale tray drier (at 80 ± 2 °C inlet temperature, 1 m s-1 air velocity) and freeze drier (13.33 kPa absolute pressure, condenser temperature of -48 ± 2 °C) were used for the drying experiments. Drying curves were fitted to six well-known thin layer drying models. Nonlinear regression analysis was used to evaluate the parameters of the selected models by using statistical software SPSS 16.0 (SPSS Inc., USA). For the convective and freeze drying processes of pumpkin slices, the highest R2 values, and the lowest RMSE as well as χ2 values were obtained from Page model. The effective moisture diffusivity (Deff) of the convective and freeze dried pumpkin slices were obtained from the Fick's diffusion model, and they were found to be 2.233 × 10-7 and 3.040 × 10-9 m2s-1, respectively. Specific moisture extraction rate, moisture extraction rate, and specific energy consumption values were almost twice in freeze drying process. Depending on the results, moisture contents and water activity values of pumpkin slices were in acceptable limits for safe storage of products. The rehydration behaviour of [at 18 ± 2 and 100 ± 2 °C for 1:25, 1:50, 1:75, 1:100, and 1:125 solid:liquid ratios (w:w)] dried pumpkin slices was determined by Peleg's model with the highest R2. The highest total soluble solid loss of pumpkin slices was observed for the rehydration experiment which performed at 1:25 solid: liquid ratio (w:w). Rehydration ratio of freeze dried slices was found 2-3 times higher than convective dried slices.

  9. Diagnostic Value of 64-Slice Dual-Source CT Coronary Angiography in Patients with Atrial Fibrillation: Comparison with Invasive Coronary Angiography

    International Nuclear Information System (INIS)

    Zhang, Jian Jun; Liu, Tie; Feng, Yue; Wu, Wei Feng; Mou, Cai Yun; Zhai, Li Hao

    2011-01-01

    We wanted to evaluate the image quality and diagnostic value of 64-slice dual-source computed tomography (DSCT) coronary angiography in patients with atrial fibrillation (Afib). The coronary arteries of 22 Afib patients seen on DSCT were classified into 15 segments and the imaging quality (excellent, good, moderate and poor) and significant stenoses (≥ 50%) were evaluated by two radiologists who were blinded to the conventional coronary angiography (CAG) results. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting important coronary artery stenosis were calculated. McNemar test was used to determine any significant difference between DSCT and CAG, and Cohen's Kappa statistics were calculated for the intermodality and interobserver agreement. The mean heart rate was 89 ± 8.3 bpm (range: 80-118 bpm). A range from 250 msec to 300 msec within the RR interval was the optimal reconstruction interval for the patients with Afib. The respective overall sensitivity, specificity, PPV and NPV values were 74%, 97%, 81% and 96% for reader 1 and 72%, 98%, 85% and 96% for reader 2. No significant difference between DSCT and CAG was found for detecting a significant stenosis (reader 1, p = 1.0; reader 2, p = 0.727). Cohen's Kappa statistics demonstrated good intermodality and interobserver agreement. 64-slice DSCT coronary angiography provides good image quality in patients with atrial fibrillation without the need for controlling the heart rate. DSCT can be used for ruling out significant stenosis in patients with atrial fibrillation with its high NPV for detecting in important stenosis.

  10. Diagnostic Value of 64-Slice Dual-Source CT Coronary Angiography in Patients with Atrial Fibrillation: Comparison with Invasive Coronary Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jian Jun; Liu, Tie; Feng, Yue; Wu, Wei Feng; Mou, Cai Yun; Zhai, Li Hao [Zhejiang Hospital, Hangzhou (China)

    2011-08-15

    We wanted to evaluate the image quality and diagnostic value of 64-slice dual-source computed tomography (DSCT) coronary angiography in patients with atrial fibrillation (Afib). The coronary arteries of 22 Afib patients seen on DSCT were classified into 15 segments and the imaging quality (excellent, good, moderate and poor) and significant stenoses ({>=} 50%) were evaluated by two radiologists who were blinded to the conventional coronary angiography (CAG) results. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting important coronary artery stenosis were calculated. McNemar test was used to determine any significant difference between DSCT and CAG, and Cohen's Kappa statistics were calculated for the intermodality and interobserver agreement. The mean heart rate was 89 {+-} 8.3 bpm (range: 80-118 bpm). A range from 250 msec to 300 msec within the RR interval was the optimal reconstruction interval for the patients with Afib. The respective overall sensitivity, specificity, PPV and NPV values were 74%, 97%, 81% and 96% for reader 1 and 72%, 98%, 85% and 96% for reader 2. No significant difference between DSCT and CAG was found for detecting a significant stenosis (reader 1, p = 1.0; reader 2, p = 0.727). Cohen's Kappa statistics demonstrated good intermodality and interobserver agreement. 64-slice DSCT coronary angiography provides good image quality in patients with atrial fibrillation without the need for controlling the heart rate. DSCT can be used for ruling out significant stenosis in patients with atrial fibrillation with its high NPV for detecting in important stenosis.

  11. A shape-based statistical method to retrieve 2D TRUS-MR slice correspondence for prostate biopsy

    Science.gov (United States)

    Mitra, Jhimli; Srikantha, Abhilash; Sidibé, Désiré; Martí, Robert; Oliver, Arnau; Lladó, Xavier; Ghose, Soumya; Vilanova, Joan C.; Comet, Josep; Meriaudeau, Fabrice

    2012-02-01

    This paper presents a method based on shape-context and statistical measures to match interventional 2D Trans Rectal Ultrasound (TRUS) slice during prostate biopsy to a 2D Magnetic Resonance (MR) slice of a pre-acquired prostate volume. Accurate biopsy tissue sampling requires translation of the MR slice information on the TRUS guided biopsy slice. However, this translation or fusion requires the knowledge of the spatial position of the TRUS slice and this is only possible with the use of an electro-magnetic (EM) tracker attached to the TRUS probe. Since, the use of EM tracker is not common in clinical practice and 3D TRUS is not used during biopsy, we propose to perform an analysis based on shape and information theory to reach close enough to the actual MR slice as validated by experts. The Bhattacharyya distance is used to find point correspondences between shape-context representations of the prostate contours. Thereafter, Chi-square distance is used to find out those MR slices where the prostates closely match with that of the TRUS slice. Normalized Mutual Information (NMI) values of the TRUS slice with each of the axial MR slices are computed after rigid alignment and consecutively a strategic elimination based on a set of rules between the Chi-square distances and the NMI leads to the required MR slice. We validated our method for TRUS axial slices of 15 patients, of which 11 results matched at least one experts validation and the remaining 4 are at most one slice away from the expert validations.

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

    Science.gov (United States)

    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.

  13. A comparative risk assessment for Listeria monocytogenes in prepackaged versus retail-sliced deli meat.

    Science.gov (United States)

    Endrikat, Sarah; Gallagher, Daniel; Pouillot, Régis; Hicks Quesenberry, Heather; Labarre, David; Schroeder, Carl M; Kause, Janell

    2010-04-01

    Deli meat was ranked as the highest-risk ready-to-eat food vehicle of Listeria monocytogenes within the 2003 U.S. Food and Drug Administration and U.S. Department of Agriculture, Food Safety and Inspection Service risk assessment. The comparative risk of L. monocytogenes in retail-sliced versus prepackaged deli meats was evaluated with a modified version of this model. Other research has found that retail-sliced deli meats have both higher prevalence and levels of L. monocytogenes than have product sliced and packaged at the manufacturer level. The updated risk assessment model considered slicing location as well as the use of growth inhibitors. The per annum comparative risk ratio for the number of deaths from retail-sliced versus prepackaged deli meats was found to be 4.89, and the per-serving comparative risk ratio was 4.27. There was a significant interaction between the use of growth inhibitors and slicing location. Almost 70% of the estimated deaths occurred from retail-sliced product that did not possess a growth inhibitor. A sensitivity analysis, assessing the effect of the model's consumer storage time and shelf life assumptions, found that even if retail-sliced deli meats were stored for a quarter of the time prepackaged deli meats were stored, retail-sliced product is 1.7 times more likely to result in death from listeriosis. Sensitivity analysis also showed that the shelf life assumption had little effect on the comparative risk ratio.

  14. Scanning and contrast enhancement protocols for multi-slice CT in evaluation of the upper abdomen

    International Nuclear Information System (INIS)

    Awai, Kazuo; Onishi, Hiromitsu; Takada, Koichi; Yamaguchi, Yasuo; Eguchi, Nobuko; Hiraishi, Kumiko; Hori, Shinichi

    2000-01-01

    The advent of multi-slice CT is one of the quantum leaps in computed tomography since the introduction of helical CT. Multi-slice CT can rapidly scan a large longitudinal (z-axis) volume with high longitudinal resolution and low image artifacts. The rapid volume coverage speed of multi-slice CT can increase the difficulty in optimizing the delay time between the beginning of contrast material injection and the acquisition of images and we need accurate knowledge about optimal temporal window for adequate contrast enhancement. High z-axis resolution of multi-slice can improve the quality of three-dimensional images and MPR images and we must select adequate slice thickness and slice intervals in each case. We discuss basic considerations for adequate contrast enhancement and scanning protocols by multi-slice CT scanner in the upper abdomen. (author)

  15. Minimally invasive neurosurgery with interventional magnetic resonance. Its present and future

    International Nuclear Information System (INIS)

    Hashimoto, Takuo

    2000-01-01

    We have used X-ray fluoroscopy, ultrasonography, and computed tomography in treatment. However, these methods do not provide precise image. Since magnetic resonance (MR) provides high-resolution images, it is more suitable in treatment. Recently open-type MR has been introduced for clinical diagnosis and treatment. Interventional MR provides a real-time images, high-resolutional images, and thermal distribution. Open MR can be used for minimally invasive neurosurgery. Interventional MR (I-MR) can be used in treatment and is extremely useful for minimally invasive surgery of the brain and spinal cord. We have used an open-type permanent MR scanner (Airis, Hitachi), for minimally invasive neurosurgery. Stereotactic brain tumor biopsy, aspiration of intracerebral hematoma, and percutaneous laser disc hernia ablation under MR guidance has been performed in our department. I-MR provided precise, and less-invasive treatment. Stereotactic biopsy was done in 12 patients with brain tumors. Precise, accurate biopsy is possible with MR fluoroscopic guidance. Hematomas were also aspirated safely and precisely by monitoring real-time image. Percutaneous laser disc hernia ablation (PLDA) was done in 201 patients with lumbar disc herniation (127 at L4/5 and 48 at L5/S1). Patients ranged in age from 17 to 72 years. A MR-compatible 18-gauge 15-cm-long titanium needle was clearly visualized and safety and accurately inserted into the disc herniation from multiple directions. Laser ablation was done (mean, 1,000 J). Signs and symptoms improved immediately after ablation. The overall success rate was 90.5% (MacNab's criteria). Two patients (1.0%) had discitis after PLDA. I-MR and fluoroscopy provide near-real-time images for treatment of brain tumors and hematoma. Precise treatment can be performed with the Patil MR-compatible stereotactic system. PLDA was performed safety and accurately with I-MR. The results were satisfactory. I-MR-PLDA is a safe, precise, and minimally invasive

  16. Minimally invasive neurosurgery with interventional magnetic resonance. Its present and future

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Takuo [Jikei Univ., Tokyo (Japan). School of Medicine

    2000-01-01

    We have used X-ray fluoroscopy, ultrasonography, and computed tomography in treatment. However, these methods do not provide precise image. Since magnetic resonance (MR) provides high-resolution images, it is more suitable in treatment. Recently open-type MR has been introduced for clinical diagnosis and treatment. Interventional MR provides a real-time images, high-resolutional images, and thermal distribution. Open MR can be used for minimally invasive neurosurgery. Interventional MR (I-MR) can be used in treatment and is extremely useful for minimally invasive surgery of the brain and spinal cord. We have used an open-type permanent MR scanner (Airis, Hitachi), for minimally invasive neurosurgery. Stereotactic brain tumor biopsy, aspiration of intracerebral hematoma, and percutaneous laser disc hernia ablation under MR guidance has been performed in our department. I-MR provided precise, and less-invasive treatment. Stereotactic biopsy was done in 12 patients with brain tumors. Precise, accurate biopsy is possible with MR fluoroscopic guidance. Hematomas were also aspirated safely and precisely by monitoring real-time image. Percutaneous laser disc hernia ablation (PLDA) was done in 201 patients with lumbar disc herniation (127 at L4/5 and 48 at L5/S1). Patients ranged in age from 17 to 72 years. A MR-compatible 18-gauge 15-cm-long titanium needle was clearly visualized and safety and accurately inserted into the disc herniation from multiple directions. Laser ablation was done (mean, 1,000 J). Signs and symptoms improved immediately after ablation. The overall success rate was 90.5% (MacNab's criteria). Two patients (1.0%) had discitis after PLDA. I-MR and fluoroscopy provide near-real-time images for treatment of brain tumors and hematoma. Precise treatment can be performed with the Patil MR-compatible stereotactic system. PLDA was performed safety and accurately with I-MR. The results were satisfactory. I-MR-PLDA is a safe, precise, and minimally

  17. Response of avian embryonic brain to spatially segmented x-ray microbeams.

    Science.gov (United States)

    Dilmanian, F A; Morris, G M; Le Duc, G; Huang, X; Ren, B; Bacarian, T; Allen, J C; Kalef-Ezra, J; Orion, I; Rosen, E M; Sandhu, T; Sathé, P; Wu, X Y; Zhong, Z; Shivaprasad, H L

    2001-05-01

    Duck embryo was studied as a model for assessing the effects of microbeam radiation therapy (MRT) on the human infant brain. Because of the high risk of radiation-induced disruption of the developmental process in the immature brain, conventional wide-beam radiotherapy of brain tumors is seldom carried out in infants under the age of three. Other types of treatment for pediatric brain tumors are frequently ineffective. Recent findings from studies in Grenoble on the brain of suckling rats indicate that MRT could be of benefit for the treatment of early childhood tumors. In our studies, duck embryos were irradiated at 3-4 days prior to hatching. Irradiation was carried out using a single exposure of synchrotron-generated X-rays, either in the form of parallel microplanar beams (microbeams), or as non-segmented broad beam. The individual microplanar beams had a width of 27 microm and height of 11 mm, and a center-to-center spacing of 100 microm. Doses to the exposed areas of embryo brain were 40, 80, 160 and 450 Gy (in-slice dose) for the microbeam, and 6, 12 and 18 Gy for the broad beam. The biological end point employed in the study was ataxia. This neurological symptom of radiation damage to the brain developed within 75 days of hatching. Histopathological analysis of brain tissue did not reveal any radiation induced lesions for microbeam doses of 40-160 Gy (in-slice), although some incidences of ataxia were observed in that dose group. However, severe brain lesions did occur in animals in the 450 Gy microbeam dose groups, and mild lesions in the 18 Gy broad beam dose group. These results indicate that embryonic duck brain has an appreciably higher tolerance to the microbeam modality, as compared to the broad beam modality. When the microbeam dose was normalized to the full volume of the irradiated tissue. i.e., the dose averaged over microbeams and the space between the microbeams, brain tolerance was estimated to be about three times higher to microbeam

  18. Significance of MDR1 and multiple drug resistance in refractory human epileptic brain

    Directory of Open Access Journals (Sweden)

    Dini Gabriele

    2004-10-01

    Full Text Available Abstract Background The multiple drug resistance protein (MDR1/P-glycoprotein is overexpressed in glia and blood-brain barrier (BBB endothelium in drug refractory human epileptic tissue. Since various antiepileptic drugs (AEDs can act as substrates for MDR1, the enhanced expression/function of this protein may increase their active extrusion from the brain, resulting in decreased responsiveness to AEDs. Methods Human drug resistant epileptic brain tissues were collected after surgical resection. Astrocyte cell cultures were established from these tissues, and commercially available normal human astrocytes were used as controls. Uptake of fluorescent doxorubicin and radioactive-labeled Phenytoin was measured in the two cell populations, and the effect of MDR1 blockers was evaluated. Frozen human epileptic brain tissue slices were double immunostained to locate MDR1 in neurons and glia. Other slices were exposed to toxic concentrations of Phenytoin to study cell viability in the presence or absence of a specific MDR1 blocker. Results MDR1 was overexpressed in blood vessels, astrocytes and neurons in human epileptic drug-resistant brain. In addition, MDR1-mediated cellular drug extrusion was increased in human 'epileptic' astrocytes compared to 'normal' ones. Concomitantly, cell viability in the presence of cytotoxic compounds was increased. Conclusions Overexpression of MDR1 in different cell types in drug-resistant epileptic human brain leads to functional alterations, not all of which are linked to drug pharmacokinetics. In particular, the modulation of glioneuronal MDR1 function in epileptic brain in the presence of toxic concentrations of xenobiotics may constitute a novel cytoprotective mechanism.

  19. Dosimetric variation due to CT inter-slice spacing in four-dimensional carbon beam lung therapy

    International Nuclear Information System (INIS)

    Kumagai, Motoki; Mori, Shinichiro; Kandatsu, Susumu; Baba, Masayuki; Sharp, Gregory C; Asakura, Hiroshi; Endo, Masahiro

    2009-01-01

    When CT data with thick slice thickness are used in treatment planning, geometrical uncertainty may induce dosimetric errors. We evaluated carbon ion dose variations due to different CT slice thicknesses using a four-dimensional (4D) carbon ion beam dose calculation, and compared results between ungated and gated respiratory strategies. Seven lung patients were scanned in 4D mode with a 0.5 mm slice thickness using a 256-multi-slice CT scanner. CT images were averaged with various numbers of images to simulate reconstructed images with various slice thicknesses (0.5-5.0 mm). Two scenarios were studied (respiratory-ungated and -gated strategies). Range compensators were designed for each of the CT volumes with coarse inter-slice spacing to cover the internal target volume (ITV), as defined from 4DCT. Carbon ion dose distribution was computed for each resulting ITV on the 0.5 mm slice 4DCT data. The accumulated dose distribution was then calculated using deformable registration for 4D dose assessment. The magnitude of over- and under-dosage was found to be larger with the use of range compensators designed with a coarser inter-slice spacing than those obtained with a 0.5 mm slice thickness. Although no under-dosage was observed within the clinical target volume (CTV) region, D95 remained at over 97% of the prescribed dose for the ungated strategy and 95% for the gated strategy for all slice thicknesses. An inter-slice spacing of less than 3 mm may be able to minimize dose variation between the ungated and gated strategies. Although volumes with increased inter-slice spacing may reduce geometrical accuracy at a certain respiratory phase, this does not significantly affect delivery of the accumulated dose to the target during the treatment course.

  20. Electroresponsive properties and membrane potential trajectories of three types of inspiratory neurons in the newborn mouse brain stem in vitro

    DEFF Research Database (Denmark)

    Rekling, J C; Champagnat, J; Denavit-Saubié, M

    1996-01-01

    with the aim of extending the classification of inspiratory neurons to include analysis of active membrane properties. 2. The slice generated a regular rhythmic motor output recorded as burst of action potentials on a XII nerve root with a peak to peak time of 11.5 +/- 3.4 s and a duration of 483 +/- 54 ms......1. The electrophysiological properties of inspiratory neurons were studied in a rhythmically active thick-slice preparation of the newborn mouse brain stem maintained in vitro. Whole cell patch recordings were performed from 60 inspiratory neurons within the rostral ventrolateral part of the slice...

  1. Normal mediastinal and hilar lymph nodes evaluated by 5 mm slice bolus injection CT scan

    International Nuclear Information System (INIS)

    Yamamoto, Takako; Tsukada, Hiroshi; Koizumi, Naoya; Akita, Shinichi; Oda, Junichi; Sakai, Kunio

    1995-01-01

    We evaluated the number and size of normal mediastinal and hilar lymph nodes by 5 mm slice bolus injection CT (12 patients), compared with 10 mm slice CT (12 patients). More lymph nodes were clearly demonstrated by 5 mm slice CT than by 10 mm slice CT. Especially left-sided tracheobronchial (no.4), subaortic (no.5), subcarinal (no.7) and hilar lymph nodes were clearly visible. We concluded 5 mm slice bolus injection CT was useful to evaluate mediastinal and hilar lymph nodes. (author)

  2. Extension of shelf-life of Chickoo slices using hurdle technology

    International Nuclear Information System (INIS)

    Shirodkar, S.; Behere, A.G.; Padwal-Desai, S.R.; Lele, S.S.; Pai, J.S.

    2001-01-01

    An attempt has been made to evolve a protocol to prepare shelf-stable high moisture chickoo slices using Hurdle Technology. The process is based on a slight reduction of water activity (0.98?0.94) by osmosis with a 70 deg Brix sucrose syrup, lowering of pH (5.75 to 4.46) by addition of citric acid, addition of KMS and then subjecting the resulting slices to different doses of gamma radiation ranging from 0.25-1 kGy. Radiation processed chickoo slices remained acceptable for 8 weeks at sub-room temperature (10 ± 2 degC) and for 3 weeks at ambient temperature (28 ± 2 degC) when evaluated by a taste-test panel. (author)

  3. Quantitative parameters of image quality in 64-slice computed tomography angiography of the coronary arteries

    International Nuclear Information System (INIS)

    Ferencik, Maros; Nomura, Cesar H.; Maurovich-Horvat, Pal; Hoffmann, Udo; Pena, Antonio J.; Cury, Ricardo C.; Abbara, Suhny; Nieman, Koen; Fatima, Umaima; Achenbach, Stephan; Brady, Thomas J.

    2006-01-01

    We explored quantitative parameters of image quality in consecutive patients undergoing 64-slice multi-detector computed tomography (MDCT) coronary angiography for clinical reasons. Forty-two patients (36 men, mean age 61 ± 11 years, mean heart rate 63 ± 10 bpm) underwent contrast-enhanced MDCT coronary angiography with a 64-slice scanner (Siemens Sensation 64, 64 mmx 0.6 mm collimation, 330 ms tube rotation, 850 mAs, 120 kV). Two independent observers measured the overall visualized vessel length and the length of the coronary arteries visualized without motion artifacts in curved multiplanar reformatted images. Contrast-to-noise ratio was measured in the proximal and distal segments of the coronary arteries. The mean length of visualized coronary arteries was: left main 12 ± 6 mm, left anterior descending 149 ± 25 mm, left circumflex 89 ± 30 mm, and right coronary artery 161 ± 38 mm. On average, 97 ± 5% of the total visualized vessel length was depicted without motion artifacts (left main 100 ± 0%, left anterior descending 97 ± 6%, left circumflex 98 ± 5%, and right coronary artery 95 ± 6%). In 27 patients with a heart rate ≤65 bpm, 98 ± 4% of the overall visualized vessel length was imaged without motion artifacts, whereas 96 ± 6% of the overall visualized vessel length was imaged without motion artifacts in 15 patients with a heart rate >65 bpm (p < 0.001). The mean contrast-to-noise ratio in all measured coronary arteries was 14.6 ± 4.7 (proximal coronary segments: range 15.1 ± 4.4 to 16.1 ± 5.0, distal coronary segments: range 11.4 ± 4.2 to 15.9 ± 4.9). In conclusion, 64-slice MDCT permits reliable visualization of the coronary arteries with minimal motion artifacts and high CNR in consecutive patients referred for non-invasive MDCT coronary angiography. Low heart rate is an important prerequisite for excellent image quality

  4. Thin-Slice Perception Develops Slowly

    Science.gov (United States)

    Balas, Benjamin; Kanwisher, Nancy; Saxe, Rebecca

    2012-01-01

    Body language and facial gesture provide sufficient visual information to support high-level social inferences from "thin slices" of behavior. Given short movies of nonverbal behavior, adults make reliable judgments in a large number of tasks. Here we find that the high precision of adults' nonverbal social perception depends on the slow…

  5. A z-gradient array for simultaneous multi-slice excitation with a single-band RF pulse.

    Science.gov (United States)

    Ertan, Koray; Taraghinia, Soheil; Sadeghi, Alireza; Atalar, Ergin

    2018-07-01

    Multi-slice radiofrequency (RF) pulses have higher specific absorption rates, more peak RF power, and longer pulse durations than single-slice RF pulses. Gradient field design techniques using a z-gradient array are investigated for exciting multiple slices with a single-band RF pulse. Two different field design methods are formulated to solve for the required current values of the gradient array elements for the given slice locations. The method requirements are specified, optimization problems are formulated for the minimum current norm and an analytical solution is provided. A 9-channel z-gradient coil array driven by independent, custom-designed gradient amplifiers is used to validate the theory. Performance measures such as normalized slice thickness error, gradient strength per unit norm current, power dissipation, and maximum amplitude of the magnetic field are provided for various slice locations and numbers of slices. Two and 3 slices are excited by a single-band RF pulse in simulations and phantom experiments. The possibility of multi-slice excitation with a single-band RF pulse using a z-gradient array is validated in simulations and phantom experiments. Magn Reson Med 80:400-412, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  6. A rapid and simple method for cryopreservation of human liver slices

    NARCIS (Netherlands)

    de Kanter, R; Olinga, Peter; Hof, I.H; de Jager, M.H; Verwillegen, W.A; Slooff, M.JH; Meijer, D.K F; Groothuis, Geny; Koster, H

    1. Precision-cut liver slices represent a suitable and convenient in vitro preparation for studying metabolism and toxicity mechanisms of drugs and toxic chemicals. Particularly in the case of human liver slices, cryopreservation would enable more efficient utilization of this scarce and irregularly

  7. Self-assembled amphiphilic core-shell nanocarriers in line with the modern strategies for brain delivery.

    Science.gov (United States)

    Elezaby, Reham S; Gad, Heba A; Metwally, Abdelkader A; Geneidi, Ahmed S; Awad, Gehanne A

    2017-09-10

    Disorders of the central nervous system (CNS) represent increasing social and economic problems all over the world which makes the effective transport of drugs to the brain a crucial need. In the last decade, many strategies were introduced to deliver drugs to the brain trying to overcome the challenge of the blood brain barrier (BBB) using both invasive and non-invasive methods. Non-invasive strategy represented in the application of nanocarriers became very common. One of the most hopeful nanoscopic carriers for brain delivery is core-shell nanocarriers or polymeric micelles (PMs). They are more advantageous than other nanocarriers. They offer small size, ease of preparation, ease of sterilization and the possibility of surface modification with various ligands. Hence, the aim of this review is to discuss modern strategies for brain delivery, micelles as a successful delivery system for the brain and how micelles could be modified to act as "magic bullets" for brain delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Establishment of multi-slice computed tomography (MSCT) reference level in Johor, Malaysia

    Science.gov (United States)

    Karim, M. K. A.; Hashim, S.; Bakar, K. A.; Muhammad, H.; Sabarudin, A.; Ang, W. C.; Bahruddin, N. A.

    2016-03-01

    Radiation doses from computed tomography (CT) are the highest and most hazardous compared to other imaging modalities. This study aimed to evaluate radiation dose in Johor, Malaysia to patients during computed tomography examinations of the brain, chest and abdomen and to establish the local diagnostic reference levels (DRLs) as are present with the current, state- of-art, multi-slice CT scanners. Survey forms were sent to five centres performing CT to obtain data regarding acquisition parameters as well as the dose information from CT consoles. CT- EXPO (Version 2.3.1, Germany) was used to validate the dose information. The proposed DRLs were indicated by rounding the third quartiles of whole dose distributions where mean values of CTDIw (mGy), CTDIvol (mGy) and DLP (mGy.cm) were comparable with other reference levels; 63, 63, and 1015 respectively for CT Brain; 15, 14, and 450 respectively for CT thorax and 16, 17, and 590 respectively for CT abdomen. The study revealed that the CT practice and dose output were revolutionised, and must keep up with the pace of introductory technology. We suggest that CTDIvol should be included in current national DRLs, as modern CTs are configured with a higher number of detectors and are independent of pitch factors.

  9. Establishment of multi-slice computed tomography (MSCT) reference level in Johor, Malaysia

    International Nuclear Information System (INIS)

    Karim, M K A; Hashim, S; Ang, W C; Bahruddin, N A; Bakar, K A; Muhammad, H; Sabarudin, A

    2016-01-01

    Radiation doses from computed tomography (CT) are the highest and most hazardous compared to other imaging modalities. This study aimed to evaluate radiation dose in Johor, Malaysia to patients during computed tomography examinations of the brain, chest and abdomen and to establish the local diagnostic reference levels (DRLs) as are present with the current, state- of-art, multi-slice CT scanners. Survey forms were sent to five centres performing CT to obtain data regarding acquisition parameters as well as the dose information from CT consoles. CT- EXPO (Version 2.3.1, Germany) was used to validate the dose information. The proposed DRLs were indicated by rounding the third quartiles of whole dose distributions where mean values of CTDI w (mGy), CTDI vol (mGy) and DLP (mGy.cm) were comparable with other reference levels; 63, 63, and 1015 respectively for CT Brain; 15, 14, and 450 respectively for CT thorax and 16, 17, and 590 respectively for CT abdomen. The study revealed that the CT practice and dose output were revolutionised, and must keep up with the pace of introductory technology. We suggest that CTDI vol should be included in current national DRLs, as modern CTs are configured with a higher number of detectors and are independent of pitch factors. (paper)

  10. 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.

  11. Adaptive SLICE method: an enhanced method to determine nonlinear dynamic respiratory system mechanics

    International Nuclear Information System (INIS)

    Zhao, Zhanqi; Möller, Knut; Guttmann, Josef

    2012-01-01

    The objective of this paper is to introduce and evaluate the adaptive SLICE method (ASM) for continuous determination of intratidal nonlinear dynamic compliance and resistance. The tidal volume is subdivided into a series of volume intervals called slices. For each slice, one compliance and one resistance are calculated by applying a least-squares-fit method. The volume window (width) covered by each slice is determined based on the confidence interval of the parameter estimation. The method was compared to the original SLICE method and evaluated using simulation and animal data. The ASM was also challenged with separate analysis of dynamic compliance during inspiration. If the signal-to-noise ratio (SNR) in the respiratory data decreased from +∞ to 10 dB, the relative errors of compliance increased from 0.1% to 22% for the ASM and from 0.2% to 227% for the SLICE method. Fewer differences were found in resistance. When the SNR was larger than 40 dB, the ASM delivered over 40 parameter estimates (42.2 ± 1.3). When analyzing the compliance during inspiration separately, the estimates calculated with the ASM were more stable. The adaptive determination of slice bounds results in consistent and reliable parameter values. Online analysis of nonlinear respiratory mechanics will profit from such an adaptive selection of interval size. (paper)

  12. Lysosome stabilization in slices of rat liver when incubated with vitamin A excess

    International Nuclear Information System (INIS)

    Morre, D.M.; Morre, D.J.; Bowen, S.; Reutter, W.

    1986-01-01

    An organ culture of slices of livers from adult rats was used to study effect of vitamin A (all-trans retinol) on lysosome stability. Lysosomes were purified by centrifugation in Percoll gradients. Preparations were monitored by electron microscopy and evaluated by morphometry and assays of marker enzymes. Enrichments relative to homogenates and crude pellets were estimated from latent (triton X-100) acid p-nitrophenylphosphatase specific activities. Lysosomes prepared from unincubated slices were enriched 50-fold in latent acid phosphatase relative to homogenates. In contrast, lysosomes prepared from slices incubated for 30 min in PBS alone were enriched only 20-fold. When 25 μg/ml retinol was included in the incubation medium, enrichments of 40-fold were obtained. The integrity of the slices was monitored by electron microscopy and their viability was confirmed by a sustained uptake and incorporation of [ 3 H]leucine into protein (up to 2 h in culture). The loss of lysosomes from homogenates of slices incubated in the absence of retinol was accompanied by a loss of acid phosphatase from the lysosomal pellet to the supernatant during purification. Addition of retinol to slices just prior to homogenization was without effect. The results demonstrate a stabilizing influence of vitamin A on lysosomes during incubation of licer slices. The findings contrast earlier reports of retinol-induced lysosome fragility in other in vitro systems

  13. Arterial displacement by the tumor demonstrated by magnetic resonance CT

    International Nuclear Information System (INIS)

    Tsuchiya, Kazuhiro; Yoshikawa, Kohki; Machida, Tohru; Iio, Masahiro.

    1985-01-01

    MR-CT permits visualization of blood vessels non-invasively. Major blood vessels in scan slices are demonstrated as structures with low or no signal intensity. In this report, two cases with brain tumor and spinal tumor are presented in which arterial displacement by the tumor was visualized by MR-CT. MR-CT is considered to be an effective method in detecting blood vessel abnormalities. (author)

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Target recognition of ladar range images using slice image: comparison of four improved algorithms

    Science.gov (United States)

    Xia, Wenze; Han, Shaokun; Cao, Jingya; Wang, Liang; Zhai, Yu; Cheng, Yang

    2017-07-01

    Compared with traditional 3-D shape data, ladar range images possess properties of strong noise, shape degeneracy, and sparsity, which make feature extraction and representation difficult. The slice image is an effective feature descriptor to resolve this problem. We propose four improved algorithms on target recognition of ladar range images using slice image. In order to improve resolution invariance of the slice image, mean value detection instead of maximum value detection is applied in these four improved algorithms. In order to improve rotation invariance of the slice image, three new improved feature descriptors-which are feature slice image, slice-Zernike moments, and slice-Fourier moments-are applied to the last three improved algorithms, respectively. Backpropagation neural networks are used as feature classifiers in the last two improved algorithms. The performance of these four improved recognition systems is analyzed comprehensively in the aspects of the three invariances, recognition rate, and execution time. The final experiment results show that the improvements for these four algorithms reach the desired effect, the three invariances of feature descriptors are not directly related to the final recognition performance of recognition systems, and these four improved recognition systems have different performances under different conditions.

  16. Complex modulation by stress of the effect of seizures on long term potentiation in mouse hippocampal slices.

    Science.gov (United States)

    Maggio, Nicola; Shavit Stein, Efrat; Segal, Menahem

    2017-08-01

    Stress has a profound effect on ability to express neuronal plasticity, learning, and memory. Likewise, epileptic seizures lead to massive changes in brain connectivity, and in ability to undergo long term changes in reactivity to afferent stimulation. In this study, we analyzed possible long lasting interactions between a stressful experience and reactivity to pilocarpine, on the ability to produce long term potentiation (LTP) in a mouse hippocampus. Pilocarpine lowers paired pulse potentiation as well as LTP in CA1 region of the mouse hippocampal slice. When stress experience precedes exposure to pilocarpine, it protects the brain from the lasting effect of pilocarpine. When stress follows pilocarpine, it exacerbates the effect of the drug, to produce a long lasting reduction in LTP. These changes are accompanied by a parallel change in blood corticosterone level. A single exposure to selective mineralo- or gluco-corticosterone (MR and GR, respectively) agonists and antagonists can mimic the stress effects, indicating that GR's underlie the lasting detrimental effects of stress whereas MRs are instrumental in counteracting the effects of stress. These studies open a new avenue of understanding of the interactive effects of stress and epileptic seizures on brain plasticity. © 2017 Wiley Periodicals, Inc.

  17. Color changes and acrylamide formation in fried potato slices

    DEFF Research Database (Denmark)

    Pedreschi, Franco; Moyano, Pedro; Kaack, Karl

    2005-01-01

    The objective of this work was to study the kinetics of browning during deep-fat frying of blanched and unblanched potato chips by using the dynamic method and to find a relationship between browning development and acrylamide formation. Prior to frying, potato slices were blanched in hot water...... at 85degreesC for 3.5 min. Unblanched slices were used as the control. Control and blanched potato slices (Panda variety, diameter: 37 mm, width: 2.2 mm) were fried at 120, 150 and 180degreesC until reaching moisture contents of similar to1.8% (total basis) and their acrylamide content and final color...... were measured. Color changes were recorded at different sampling times during frying at the three mentioned temperatures using the chromatic redness parameter a(*). Experimental data of surface temperature, moisture content and color change in potato chips during frying were fit to empirical...

  18. Thin slices and Sherlock Holmes

    African Journals Online (AJOL)

    based on very little information, and often in a matter of seconds. This is partly based on very narrow slices of our experience, and involves pattern recognition, as well as the memory banks of our senses. It is also partly a heuristic process whereby one rapidly discards ideas or notions, or promotes other hypotheses, as one.

  19. Exploring the brain

    International Nuclear Information System (INIS)

    Bloch, G.; Vernier, P.; Le Bihan, D.; Comtat, C.; Van Wassenhove, V.; Texier, I.; Planat-Chretien, A.; Poher, V.; Dinten, J.M.; Pannetier-lecoeur, M.; Trebossen, R.; Lethimonnier, F.; Eger, E.; Thirion, B.; Dehaene-Lambertz, G.; Piazza, M.; Mangin, J.F.; Dehaene, S.; Pallier, C.; Marti, S.; Klein, E.; Martinot, J.L.; Paillere, M.L.; Artiges, E.; Lemaitre, H.; Karila, L.; Houenou, J.; Sarrazin, S.; Hantraye, P.; Aron Badin, R.; Mergui, S.; Palfi, S.; Bemelmans, A.; Berger, F.; Frouin, V.; Pinel, J.F.; Crivello, F.; Mazoyer, B.; Flury-Herard, A.

    2014-01-01

    CEA (French Alternative Energies and Atomic Energy Commission) has been involved in brain research for over 50 years and this 62. issue of 'Clefs CEA' is the best occasion to come back on the latest advances in this wide field. The purpose is to show how neuroimaging combined with neuro sciences and computational sciences has shed light on various aspects of the brain life and experience such as for instance learning (with highlights on dyslexia and dyscalculia), vision, the feeling of time, consciousness, addictions, ageing, and neuro-degenerative diseases. This document is divided into 6 parts: 1) non-invasive exploration of the brain, 2) development, learning and plasticity of the brain, 3) cognitive architecture and the brain, 4) mental health and vulnerability, 5) neuro-degenerative diseases, and 6) identifying bio-markers for cerebral disorders. (A.C.)

  20. Determination of boron distribution in rat's brain, kidney and liver

    Energy Technology Data Exchange (ETDEWEB)

    Pazirandeh, Ali [Nuclear Engineering Department, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Science and Technology Research Center, AEOI, Tehran (Iran, Islamic Republic of)], E-mail: paziran@khayam.ut.ac.ir; Jameie, Behnam [Neuroscience Lab, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Zargar, Maysam [Nuclear Engineering Department, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2009-07-15

    To determine relative boron distribution in rat's brain, liver and kidney, a mixture of boric acid and borax, was used. After transcardial injection of the solution, the animals were sacrificed and the brain, kidney and liver were removed. The coronal sections of certain areas of the brain were prepared by freezing microtome. The slices were sandwiched within two pieces of CR-39. The samples were bombarded in a thermal neutron field of the TRR pneumatic facility. The alpha tracks are registered on CR-39 after being etched in NaOH. The boron distribution was determined by counting these alpha tracks CR-39 plastics. The distribution showed non-uniformity in brain, liver and kidney.

  1. Using Brain Electrical Activity Mapping to Diagnose Learning Disabilities.

    Science.gov (United States)

    Torello, Michael, W.; Duffy, Frank H.

    1985-01-01

    Cognitive neuroscience assumes that measurement of brain electrical activity should relate to cognition. Brain Electrical Activity Mapping (BEAM), a non-invasive technique, is used to record changes in activity from one brain area to another and is 80 to 90 percent successful in classifying subjects as dyslexic or normal. (MT)

  2. Sporadic meningioangiomatosis-associated atypical meningioma mimicking parenchymal invasion of brain: a case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Luo Bo-ning

    2010-06-01

    Full Text Available Abstract Meningioangiomatosis is a rare hamartomatous lesion or meningiovascular malformation in brain. In extremely rare condition, meningioma may occur together with meningioangiomatosis, and only 19 cases have been described in English literature until now. We now report a case of meningioangiomatosis-associated meningioma with atypical and clear cell variant. A 34-year-old man presented a 3-month history of progressive numbness and weakness of his left lower extremity. He had no stigmata of neurofibromatosis type 2. Magnetic resonance imaging (MRI revealed multifocal lesions in the right frontoparietal lobe. The lesions were totally removed. Microscopically, parts of lesions were atypical and clear cell meningioma corresponding to WHO grade II. The adjacent brain parenchyma showed the histological features of meningioangiomatosis. Neoplastic cells in atypical meningioma area were immunoreactive to epithelial membrane antigen (EMA with high MIB-1 index of up to 20%. However, the spindle cells in meningioangiomatosis area were negative for EMA with low MIB-1 index of up to 1%. The diagnosis of atypical meningioma associated with sporadic meningioangiomatosis was made. To our knowledge, this is the first case of a meningioangiomatosis-associated meningioma with atypical and clear cell variant component to be described. The patient had been followed-up for 11 months without adjuvant radiotherapy or chemotherapy. No tumor recurrence was found during this period. Meningioangiomatosis-associated meningioma is more likely to occur in younger patients and histologically to mimic parenchymal invasion of brain. We suggest that postoperative radiotherapy or chemotherapy should be given careful consideration to avoid over-treatment due to erroneously interpret as malignant meningioma.

  3. Evaluation of spinal cord vessels using multi-slice CT angiography

    International Nuclear Information System (INIS)

    Chen Shuang; Zhu Ruijiang; Feng Xiaoyuan

    2006-01-01

    Objective: To evaluate the value of Multi-slice spiral CT angiography for spinal cord vessels. Methods: 11 adult subjects with suspected of myelopathy were performed with Multi-slice spiral CT angiography, An iodine contrast agent was injected at 3.5 ml/s, for total 100 ml. The parameters were axial 16 slice mode, 0.625 mm slice thickness, 0.8 s rotation, delay time depending on smartprep(15-25 s), multi-phase scan. The coronal and sagittal MPR and SSD were generated on a workstation compared with spinal digital subtraction angiography (DSA) to analyze normal or abnormal spinal cord vessels. Results: Normal findings at spinal CTA and digital subtraction angiography in six adult normal subjects and spinal cord vascular malformations (1 intradural extramedullary AVF, 4 dural AVFs) in five cases, Recognizable intradural vessels corresponding to anterior median (midline) veins and/or anterior spinal arteries were show in six adult normal subjects. Abnormal intradural vessels were detected in all five spinal cord vascular malformation with CT angiography, in comparison with digital subtraction angiography these vessels were primarily enlarged veins of the coronal venous plexus on the cord surface, radiculomedullary-dural arteries could not be clearly shown in four dural AVF, only one anterior spinal artery was detected in one patient with intradural medullary AVF, which direct shunt between anterior spinal artery and perimedullary vein with tortuous draining vessel. Conclusion: Multi-slice CT angiography is able to visualize the normal or abnormal spinal cord vessels. It could be used as a noninvasive method to screen the spinal cord vascular disease. (authors)

  4. Stereotactically Standard Areas: Applied Mathematics in the Service of Brain Targeting in Deep Brain Stimulation.

    Science.gov (United States)

    Mavridis, Ioannis N

    2017-12-11

    The concept of stereotactically standard areas (SSAs) within human brain nuclei belongs to the knowledge of the modern field of stereotactic brain microanatomy. These are areas resisting the individual variability of the nuclear location in stereotactic space. This paper summarizes the current knowledge regarding SSAs. A mathematical formula of SSAs was recently invented, allowing for their robust, reproducible, and accurate application to laboratory studies and clinical practice. Thus, SSAs open new doors for the application of stereotactic microanatomy to highly accurate brain targeting, which is mainly useful for minimally invasive neurosurgical procedures, such as deep brain stimulation.

  5. Stereotactically Standard Areas: Applied Mathematics in the Service of Brain Targeting in Deep Brain Stimulation

    Directory of Open Access Journals (Sweden)

    Ioannis N. Mavridis

    2017-12-01

    Full Text Available The concept of stereotactically standard areas (SSAs within human brain nuclei belongs to the knowledge of the modern field of stereotactic brain microanatomy. These are areas resisting the individual variability of the nuclear location in stereotactic space. This paper summarizes the current knowledge regarding SSAs. A mathematical formula of SSAs was recently invented, allowing for their robust, reproducible, and accurate application to laboratory studies and clinical practice. Thus, SSAs open new doors for the application of stereotactic microanatomy to highly accurate brain targeting, which is mainly useful for minimally invasive neurosurgical procedures, such as deep brain stimulation.

  6. Advanced signal processing theory and implementation for sonar, radar, and non-invasive medical diagnostic systems

    CERN Document Server

    Stergiopoulos, Stergios

    2009-01-01

    Integrates topics of signal processing from sonar, radar, and medical system technologies by identifying their concept similarities. This book covers non-invasive medical diagnostic system applications, including intracranial ultrasound, a technology that attempts to address non-invasive detection on brain injuries and stroke.

  7. Photon Entanglement Through Brain Tissue.

    Science.gov (United States)

    Shi, Lingyan; Galvez, Enrique J; Alfano, Robert R

    2016-12-20

    Photon entanglement, the cornerstone of quantum correlations, provides a level of coherence that is not present in classical correlations. Harnessing it by study of its passage through organic matter may offer new possibilities for medical diagnosis technique. In this work, we study the preservation of photon entanglement in polarization, created by spontaneous parametric down-conversion, after one entangled photon propagates through multiphoton-scattering brain tissue slices with different thickness. The Tangle-Entropy (TS) plots show the strong preservation of entanglement of photons propagating in brain tissue. By spatially filtering the ballistic scattering of an entangled photon, we find that its polarization entanglement is preserved and non-locally correlated with its twin in the TS plots. The degree of entanglement correlates better with structure and water content than with sample thickness.

  8. Clinical application of Half Fourier Acquisition Single Shot Turbo Spin Echo (HASTE) imaging accelerated by simultaneous multi-slice acquisition.

    Science.gov (United States)

    Schulz, Jenni; P Marques, José; Ter Telgte, Annemieke; van Dorst, Anouk; de Leeuw, Frank-Erik; Meijer, Frederick J A; Norris, David G

    2018-01-01

    As a single-shot sequence with a long train of refocusing pulses, Half-Fourier Acquisition Single-Shot Turbo-Spin-Echo (HASTE) suffers from high power deposition limiting use at high resolutions and high field strengths, particularly if combined with acceleration techniques such as simultaneous multi-slice (SMS) imaging. Using a combination of multiband (MB)-excitation and PINS-refocusing pulses will effectively accelerate the acquisition time while staying within the SAR limitations. In particular, uncooperative and young patients will profit from the speed of the MB-PINS HASTE sequence, as clinical diagnosis can be possible without sedation. Materials and MethodsMB-excitation and PINS-refocusing pulses were incorporated into a HASTE-sequence with blipped CAIPIRINHA and TRAPS including an internal FLASH reference scan for online reconstruction. Whole brain MB-PINS HASTE data were acquired on a Siemens 3T-Prisma system from 10 individuals and compared to a clinical HASTE protocol. ResultsThe proposed MB-PINS HASTE protocol accelerates the acquisition by about a factor 2 compared to the clinical HASTE. The diagnostic image quality proved to be comparable for both sequences for the evaluation of the overall aspect of the brain, the detection of white matter changes and areas of tissue loss, and for the evaluation of the CSF spaces although artifacts were more frequently encountered with MB-PINS HASTE. ConclusionsMB-PINS HASTE enables acquisition of slice accelerated highly T2-weighted images and provides good diagnostic image quality while reducing acquisition time. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Taurine Induces Proliferation of Neural Stem Cells and Synapse Development in the Developing Mouse Brain

    Science.gov (United States)

    Shivaraj, Mattu Chetana; Marcy, Guillaume; Low, Guoliang; Ryu, Jae Ryun; Zhao, Xianfeng; Rosales, Francisco J.; Goh, Eyleen L. K.

    2012-01-01

    Taurine is a sulfur-containing amino acid present in high concentrations in mammalian tissues. It has been implicated in several processes involving brain development and neurotransmission. However, the role of taurine in hippocampal neurogenesis during brain development is still unknown. Here we show that taurine regulates neural progenitor cell (NPC) proliferation in the dentate gyrus of the developing brain as well as in cultured early postnatal (P5) hippocampal progenitor cells and hippocampal slices derived from P5 mice brains. Taurine increased cell proliferation without having a significant effect on neural differentiation both in cultured P5 NPCs as well as cultured hippocampal slices and in vivo. Expression level analysis of synaptic proteins revealed that taurine increases the expression of Synapsin 1 and PSD 95. We also found that taurine stimulates the phosphorylation of ERK1/2 indicating a possible role of the ERK pathway in mediating the changes that we observed, especially in proliferation. Taken together, our results demonstrate a role for taurine in neural stem/progenitor cell proliferation in developing brain and suggest the involvement of the ERK1/2 pathways in mediating these actions. Our study also shows that taurine influences the levels of proteins associated with synapse development. This is the first evidence showing the effect of taurine on early postnatal neuronal development using a combination of in vitro, ex-vivo and in vivo systems. PMID:22916184

  10. Non-invasive quantitation of phosphorus metabolites in human brain and brain tumors by magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Naruse, Shoji; Higuchi, Toshihiro; Horikawa, Yoshiharu; Tanaka, Chuzo; Roth, K.; Hubesch, B.; Meyerhoff, D.J.; Weiner, M.W.

    1989-01-01

    In obtaining localized magnetic resonance spectra in the clinical setting, the exact determination of volume of interest (VOI), the relative sensitivity of detection within the VOI, the inhomogeneity of B 1 field, the Q factor of the coil, and saturation factors should be considered. Taking these items into account, a quantitative method for calculating the absolute amount of phosphorus metabolites was developed. Using this method, phosphorus metabolites in the brain were determined in 15 patients with brain tumors - meningioma (8) and astrocytoma (7), and 10 normal volunteers. The integrals for metabolite signals were determined by using the curve-fitting software. The concentrations for ATP, PCr, PDE, inorganic orthophosphate (Pi), and phosphomonosters (PME) were 2.5, 4.9, 11.3, 1.9 and 3.9 mM, respectively, in the normal brain. For the brain tumors, phosphorus metabolites were decreased, except for Pi and PME. These results encourage the clinical use of this method in the quantitative analysis of metabolites of the diseased brain. (Namekawa, K)

  11. Non invasive brain stimulation to enhance post-stroke recovery

    OpenAIRE

    Nathalie Kubis; Nathalie Kubis

    2016-01-01

    Brain plasticity after stroke remains poorly understood. Patients may improve spontaneously within the first 3 months and then more slowly in the coming year. The first days, decreased edema and reperfusion of the ischemic penumbra may possibly account for these phenomena, but the improvement during the next weeks suggests plasticity phenomena and cortical reorganization of the brain ischemic areas and of more remote areas. Indeed, the injured ischemic motor cortex has a reduced cortical exci...

  12. Non-Invasive Brain Stimulation to Enhance Post-Stroke Recovery

    OpenAIRE

    Kubis, Nathalie

    2016-01-01

    Brain plasticity after stroke remains poorly understood. Patients may improve spontaneously within the first 3 months and then more slowly in the coming year. The first day, decreased edema and reperfusion of the ischemic penumbra may possibly account for these phenomena, but the improvement during the next weeks suggests plasticity phenomena and cortical reorganization of the brain ischemic areas and of more remote areas. Indeed, the injured ischemic motor cortex has a reduced cortical excit...

  13. Development of an electrically operated cassava slicing machine

    Directory of Open Access Journals (Sweden)

    I. S. Aji

    2013-08-01

    Full Text Available Labor input in manual cassava chips processing is very high and product quality is low. This paper presents the design and construction of an electrically operated cassava slicing machine that requires only one person to operate. Efficiency, portability, ease of operation, corrosion prevention of slicing component of the machine, force required to slice a cassava tuber, capacity of 10 kg/min and uniformity in the size of the cassava chips were considered in the design and fabrication of the machine. The performance of the machine was evaluated with cassava of average length and diameter of 253 mm and 60 mm respectively at an average speed of 154 rpm. The machine produced 5.3 kg of chips of 10 mm length and 60 mm diameter in 1 minute. The efficiency of the machine was 95.6% with respect to the quantity of the input cassava. The chips were found to be well chipped to the designed thickness, shape and of generally similar size. Galvanized steel sheets were used in the cutting section to avoid corrosion of components. The machine is portable and easy to operate which can be adopted for cassava processing in a medium size industry.

  14. Effect of (+)-amphetamine on the retention of 3H-catecholamines in slices of normal and reserpinized rat brain and heart

    International Nuclear Information System (INIS)

    Ross, S.B.; Renyi, A.L.

    1978-01-01

    The effect of reserpine on the inhibition by (+)-amphetamine and cocaine of the accumulation of 3 H-dopamine (DA) in striatal slices and 3 H-noradrenaline (NA) in slices of cerebral occipital cortex and heart atrium of rats and the release of the 3 H-amines from these tissues were examined. Reserpine (5 mg/kg intraperitoneally) was injected 18 hours before the experiments. It was found that reserpine markedly enhanced the in vitro potency of amphetamine in the striatum and heart but only slightly in the cortex. After administration in vivo (+)-amphetamine was about 10 times more potent in reducing the amine accumulation in the cortex as in the striatum. Reserpine enhanced the effect in both regions. The inhibitory potency of cocaine in vitro was unchanged by reserpine in the striatum but was reduced in the cortex and heart. Reserpine did not change the inhibitory potency of desipramine in the cortex and heart. The release of the 3 H-amines by (+)-amphetamine was enhanced by reserpine in the striatum and heart but the small release produced in the cortex was not increased. The release produced by cocaine was similarly enhanced by reserpine but cocaine was much less active than (+)-amphetamine. The results indicate that (+)-amphetamine and cocaine inhibit the amine accumulation by different mechanisms. (author)

  15. Evaluation of accuracy in target positions of multmodality imaging using brain phantom

    Energy Technology Data Exchange (ETDEWEB)

    Juh, R. H.; Suh, T. S.; Chung, Y. A. [The Catholic University of Korea, Seoul (Korea, Republic of)

    2002-07-01

    Determination of target positions in radiation therapy or radiosurgery is critical to the successful treatment. It is often difficult to recognize the target position only from single image modality since each image modality has unique image pattern and image distortion problem. The purpose of this study is to evaluate the accuracy of target positions with multimodality brain phantom. We obtained CT, MR, and SPECT scan images with the specially designed brain phantom. Brain phantom consists of brain for images and frame for localization. The phantom was a water fillable cylinder containing 58 axial layers of 2.0 mm thickness. Each layer allows water to permeate various regions to match gray matter to white matter of 1:1 ratio. Localization frame with 5mm inner diameter and 150/160 mm length were attached to the outside of the brain slice and inside of the phantom cylinder. The phantom was filled with 0.16 M CuSO{sub 4} solution for MRI scan, and distilled water for CT and 15mCi (555 MBq) Tc-99m for SPECT. Axial slice images and volume images including the targets and localizer were obtained for each modality. To evaluate the errors in target positions, the position of localization and target balls measured in SPECT were compared with MR and CT. Transformation parameters for translation, rotation and scaling were determined by surface matching each SPECT with MR and CT images. Multimodality phantom was very useful to evaluate the accuracy of target positions among the different types of image modality such as CT, MR and SPECT.

  16. Usefulness of simulation with multi-slice CT for laparoscopic nephrectomy

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Yuji; Ishifuro, Minoru; Ookubo, Masaomi [Hiroshima Univ. (Japan). Hospital] (and others)

    2002-12-01

    In recent years, laparoscopic surgery has attracted attention as a minimally invasive type of surgery because of the small surgical wounds and early recovery it provides. We carry out this technique on the basis of volume data that we make use of in multi-slice CT imaging technology in laparoscopic nephrectomy by the retroperitoneal approach, and we have created CT virtual laparoscopy by virtual endoscopic display as an intra-operative navigator with an image analysis system. We provide information on detailed vascular anatomy to form intra-operative images that act as similar support images. With the provision of this volume data, we consider virtual endoscopic display the most suitable method for surgery. When we perform virtual laparoscopy, we simulate the insertion point and angle, the order of vascular structures and their locations, the number of arteries and veins, and their bifurcation points and ligation points in conjunction with the surgeon prior to operation. As the branch patterns of the renal artery are varied, perioperative confusion and surgical mishaps can be avoided through the information that is provided beforehand. Thus surgery is more accurate and proceeds more smoothly, because the surgeon has accurate anatomical information. In addition, the time required for surgery is decreased, reducing risk and the possibility of complications. (author)

  17. Usefulness of simulation with multi-slice CT for laparoscopic nephrectomy

    International Nuclear Information System (INIS)

    Akiyama, Yuji; Ishifuro, Minoru; Ookubo, Masaomi

    2002-01-01

    In recent years, laparoscopic surgery has attracted attention as a minimally invasive type of surgery because of the small surgical wounds and early recovery it provides. We carry out this technique on the basis of volume data that we make use of in multi-slice CT imaging technology in laparoscopic nephrectomy by the retroperitoneal approach, and we have created CT virtual laparoscopy by virtual endoscopic display as an intra-operative navigator with an image analysis system. We provide information on detailed vascular anatomy to form intra-operative images that act as similar support images. With the provision of this volume data, we consider virtual endoscopic display the most suitable method for surgery. When we perform virtual laparoscopy, we simulate the insertion point and angle, the order of vascular structures and their locations, the number of arteries and veins, and their bifurcation points and ligation points in conjunction with the surgeon prior to operation. As the branch patterns of the renal artery are varied, perioperative confusion and surgical mishaps can be avoided through the information that is provided beforehand. Thus surgery is more accurate and proceeds more smoothly, because the surgeon has accurate anatomical information. In addition, the time required for surgery is decreased, reducing risk and the possibility of complications. (author)

  18. A fourth gradient to overcome slice dependent phase effects of voxel-sized coils in planar arrays.

    Science.gov (United States)

    Bosshard, John C; Eigenbrodt, Edwin P; McDougall, Mary P; Wright, Steven M

    2010-01-01

    The signals from an array of densely spaced long and narrow receive coils for MRI are complicated when the voxel size is of comparable dimension to the coil size. The RF coil causes a phase gradient across each voxel, which is dependent on the distance from the coil, resulting in a slice dependent shift of k-space. A fourth gradient coil has been implemented and used with the system's gradient set to create a gradient field which varies with slice. The gradients are pulsed together to impart a slice dependent phase gradient to compensate for the slice dependent phase due to the RF coils. However the non-linearity in the fourth gradient which creates the desired slice dependency also results in a through-slice phase ramp, which disturbs normal slice refocusing and leads to additional signal cancelation and reduced field of view. This paper discusses the benefits and limitations of using a fourth gradient coil to compensate for the phase due to RF coils.

  19. Robust methods to create ex vivo minimum deformation atlases for brain mapping.

    Science.gov (United States)

    Janke, Andrew L; Ullmann, Jeremy F P

    2015-02-01

    Highly detailed ex vivo 3D atlases of average structure are of critical importance to neuroscience and its current push to understanding the global microstructure of the brain. Multiple single slice histology sections can no longer provide sufficient detail of inter-slice microstructure and lack out of plane resolution. Two ex vivo methods have emerged that can create such detailed models. High-field micro MRI with the addition of contrast media has allowed intact whole brain microstructure imaging with an isotropic resolution of 15 μm in mouse. Blockface imaging has similarly evolved to a point where it is now possible to image an entire brain in a rigorous fashion with an out of plane resolution of 10 μm. Despite the destruction of the tissue as part of this process it allows a reconstructed model that is free from cutting artifacts. Both of these methods have been utilised to create minimum deformation atlases that are representative of the respective populations. The MDA atlases allow us unprecedented insight into the commonality and differences in microstructure in cortical structures in specific taxa. In this paper we provide an overview of how to create such MDA models from ex vivo data. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Central coordination difficulty and brain CT in infancy

    International Nuclear Information System (INIS)

    Hiraiwa, Mikio; Nonaka, Chizuru; Abe, Toshiaki; Ohmi, Kazuhiko; Togo, Tomoko

    1980-01-01

    Brain CT (Computed Tomography) was performed in eighteen infants, eight males and ten females, one-month-old to twelve-month-old with central coordination difficulty (CCD) in General Electrics (U.S.A.) model CT/T-8800. Analyses of CT findings were enforced with two dimensional measurement which we previously reported. We measured intracranial area, brain area, ventricular area, and bifrontal fluid collection (low density area between skull and anterior side of the frontal lobe). Each slices we measured were through foramen of Monro by fifteen-degree declined from cantho-meatal line. Patients with CCD had higher amount of accumulated bifrontal fluid collection on the CT compared with those without CCD. Brain area index (brain area x100/intracranial area) also showed diagnostic value for CCD. Patients with CCD had lower brain area index than those without CCD. Ventricular area index (ventricular area x100/intracranial area) was less appropriate index for CCD than accumulated bifrontal fluid collection and brain area index. We thought that CT findings of the patients with CCD in infancy were characteristic in accumulated bifrontal fluid collection and reduced brain area index. (author)

  1. Unsupervised motion-compensation of multi-slice cardiac perfusion MRI

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Ólafsdóttir, Hildur; Larsson, Henrik B. W.

    2005-01-01

    This paper presents a novel method for registration of single and multi-slice cardiac perfusion MRI. Utilising computer intensive analyses of variance and clustering in an annotated training set off-line, the presented method is capable of providing registration without any manual interaction...... in less than a second per frame. Changes in image intensity during the bolus passage are modelled by a slice-coupled active appearance model, which is augmented with a cluster analysis of the training set. Landmark correspondences are optimised using the MDL framework due to Davies et al. Image search...

  2. Age-related brain atrophy and mental deterioration - a study with computed tomography

    International Nuclear Information System (INIS)

    Ito, M.; Hatazawa, J.; Yamaura, H.; Matsuzawa, T.

    1981-01-01

    The relation of brain atrophy measured with computed tomography (CT) to mental deterioration on living people was studied. A newly improved technique for quantitative measurement of brain atrophy was developed. The pixels inside the head slices were divided into three parts; brain skull, and cerebrospinal fluid according to their CT number. The volume of brain, CSF, and cranial cavity were calculated by counting the number of pixels of each tissue. Results from 130 normal brains showed that the CSF volume was constant at about 16 ml through 20-39 years old. After 40 years the mean CSF volume increased drastically and reached 71 ml in the seventies. The volume of the brain was standardized for comparison between different-sized heads (brain volume index: BVI). The mean BVI decreased with statistical significance after 40 years of age. Mental function of these persons were evaluated using Hasegawa's dementia rating scale for the elderly. Progression of brain atrophy accompanied loss of mental activities (p<0.01). (author)

  3. Three-dimensional macroporous nanoelectronic networks as minimally invasive brain probes

    Science.gov (United States)

    Xie, Chong; Liu, Jia; Fu, Tian-Ming; Dai, Xiaochuan; Zhou, Wei; Lieber, Charles M.

    2015-12-01

    Direct electrical recording and stimulation of neural activity using micro-fabricated silicon and metal micro-wire probes have contributed extensively to basic neuroscience and therapeutic applications; however, the dimensional and mechanical mismatch of these probes with the brain tissue limits their stability in chronic implants and decreases the neuron-device contact. Here, we demonstrate the realization of a three-dimensional macroporous nanoelectronic brain probe that combines ultra-flexibility and subcellular feature sizes to overcome these limitations. Built-in strains controlling the local geometry of the macroporous devices are designed to optimize the neuron/probe interface and to promote integration with the brain tissue while introducing minimal mechanical perturbation. The ultra-flexible probes were implanted frozen into rodent brains and used to record multiplexed local field potentials and single-unit action potentials from the somatosensory cortex. Significantly, histology analysis revealed filling-in of neural tissue through the macroporous network and attractive neuron-probe interactions, consistent with long-term biocompatibility of the device.

  4. Fan beam image reconstruction with generalized Fourier slice theorem.

    Science.gov (United States)

    Zhao, Shuangren; Yang, Kang; Yang, Kevin

    2014-01-01

    For parallel beam geometry the Fourier reconstruction works via the Fourier slice theorem (or central slice theorem, projection slice theorem). For fan beam situation, Fourier slice can be extended to a generalized Fourier slice theorem (GFST) for fan-beam image reconstruction. We have briefly introduced this method in a conference. This paper reintroduces the GFST method for fan beam geometry in details. The GFST method can be described as following: the Fourier plane is filled by adding up the contributions from all fanbeam projections individually; thereby the values in the Fourier plane are directly calculated for Cartesian coordinates such avoiding the interpolation from polar to Cartesian coordinates in the Fourier domain; inverse fast Fourier transform is applied to the image in Fourier plane and leads to a reconstructed image in spacial domain. The reconstructed image is compared between the result of the GFST method and the result from the filtered backprojection (FBP) method. The major differences of the GFST and the FBP methods are: (1) The interpolation process are at different data sets. The interpolation of the GFST method is at projection data. The interpolation of the FBP method is at filtered projection data. (2) The filtering process are done in different places. The filtering process of the GFST is at Fourier domain. The filtering process of the FBP method is the ramp filter which is done at projections. The resolution of ramp filter is variable with different location but the filter in the Fourier domain lead to resolution invariable with location. One advantage of the GFST method over the FBP method is in short scan situation, an exact solution can be obtained with the GFST method, but it can not be obtained with the FBP method. The calculation of both the GFST and the FBP methods are at O(N^3), where N is the number of pixel in one dimension.

  5. The role of drebrin in glioma migration and invasion

    Energy Technology Data Exchange (ETDEWEB)

    Terakawa, Yuzo [The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario (Canada); Department of Neurosurgery, Osaka City University Graduate School of Medicine, Osaka (Japan); Agnihotri, Sameer; Golbourn, Brian; Nadi, Mustafa; Sabha, Nesrin; Smith, Christian A. [The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario (Canada); Croul, Sidney E. [The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario (Canada); Division of Neuropathology, University Health Network, Department of Laboratory Medicine and Pathobiology (Canada); Rutka, James T., E-mail: james.rutka@sickkids.ca [The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario (Canada); Department of Surgery, University of Toronto, Toronto, Ontario (Canada)

    2013-02-15

    Glioblastoma (GBM) is the most common primary brain tumor in adults. Despite current advances in therapy consisting of surgery followed by chemotherapy and radiation, the overall survival rate still remains poor. Therapeutic failures are partly attributable to the highly infiltrative nature of tumor adjacent to normal brain parenchyma. Recently, evidence is mounting to suggest that actin cytoskeleton dynamics are critical components of the cell invasion process. Drebrin is an actin-binding protein involved in the regulation of actin filament organization, and plays a significant role in cell motility; however, the role of drebrin in glioma cell invasiveness has not yet been fully elucidated. Therefore, this study was aimed to clarify the role of drebrin in glioma cell morphology and cell motility. Here we show that drebrin is expressed in glioma cell lines and in operative specimens of GBM. We demonstrate that stable overexpression of drebrin in U87 cells leads to alterations in cell morphology, and induces increased invasiveness in vitro while knockdown of drebrin in U87 cells by small interfering RNA (siRNA) decreases invasion and migration. In addition, we show that depletion of drebrin by siRNA alters glioma cell morphology in A172 GBM cell line. Our results suggest that drebrin contributes to the maintenance of cell shape, and may play an important role in glioma cell motility. - Highlights: ► Drebrin is an actin-binding protein aberrantly expressed in several cancers. ► Role of drebrin in glioma cell morphology and motility is previously unknown. ► We demonstrate that drebrin is expressed in 40% of glioblastoma specimens. ► Drebrin plays a significant role in modulating glioma cell migration and invasion.

  6. Relationship between moisture content and electrical impedance of carrot slices during drying

    Science.gov (United States)

    Kertész, Ákos; Hlaváčová, Zuzana; Vozáry, Eszter; Staroňová, Lenka

    2015-01-01

    Electrical properties of food materials can give information about the inner structure and physiological state of biological tissues. Generally, the process of drying of fruits and vegetables is followed by weight loss. The aim of this study was to measure the impedance spectra of carrot slices during drying and to correlate impedance parameters to moisture content in different drying periods. Cylindrical slices were cut out from the carrot root along the axis. The slices were dried in a Venticell 111 air oven at 50°C. The weight of the slices was measured with a Denver SI-603 electronic analytical and precision balance. The weighing of the samples was performed every 30 min at the beginning of drying and every 60 min after the process. The moisture content of the samples was calculated on wet basis. The magnitude and phase angle of electrical impedance of the slices were measured with HP 4284A and 4285A precision LCR meters in the frequency range from 30 Hz to 1 MHz and from 75 kHz to 30 MHz, respectively, at voltage 1 V. The impedance measurement was performed after weighting. The change in the magnitude of impedance during drying showed a good correlation with the change in the moisture content.

  7. A review of the new minimally invasive brain stimulation techniques in psychiatry Revisão de novas técnicas minimamente invasivas de estimulação cerebral em psiquiatria

    Directory of Open Access Journals (Sweden)

    Jeong-Ho Chae

    2001-06-01

    Full Text Available New knowledge about the specific brain regions involved in neuropsychiatric disorders is rapidly evolving due to recent advances in functional neuroimaging techniques. The ability to stimulate the brain in awake alert adults without neurosurgery is a real advance that neuroscientists have long dreamed for. Several novel and minimally invasive techniques to stimulate the brain have recently developed. Among these newer somatic interventions, transcranial magnetic stimulation (TMS, vagus nerve stimulation (VNS and deep brain stimulation (DBS show promise as therapeutic tools in the treatment of neuropsychiatric disorders. This article reviews the history, methodology, and the future of these minimally invasive brain stimulation (MIBS techniques and their emerging research and therapeutic applications in psychiatryO conhecimento acerca de regiões específicas do cérebro envolvidas em transtornos psiquiátricos está em franca expansão como resultado dos avanços recentes em técnicas de neuroimagem funcional. A capacidade de estimular o cérebro em adultos despertos em estado de alerta, sem necessidade de neurocirurgia, é um avanço real sonhado havia muito pelos neurocientistas. Recentemente, desenvolveram-se várias novas técnicas minimamente invasivas para estimular o cérebro. Entre essas novas intervenções somáticas, a estimulação transcraniana magnética (ETM, a estimulação do nervo vago (ENV e a estimulação cerebral profunda (ECP revelam-se promissoras ferramentas terapêuticas no tratamento de transtornos neuropsiquiátricos. Neste artigo se faz uma revisão da história, da metodologia e das perspectivas futuras das técnicas minimamente invasivas de estimulação cerebral (ECMI e das pesquisas e aplicações terapêuticas em psiquiatria

  8. Mechanisms of CNS invasion and damage by parasites.

    Science.gov (United States)

    Kristensson, Krister; Masocha, Willias; Bentivoglio, Marina

    2013-01-01

    Invasion of the central nervous system (CNS) is a most devastating complication of a parasitic infection. Several physical and immunological barriers provide obstacles to such an invasion. In this broad overview focus is given to the physical barriers to neuroinvasion of parasites provided at the portal of entry of the parasites, i.e., the skin and epithelial cells of the gastrointestinal tract, and between the blood and the brain parenchyma, i.e., the blood-brain barrier (BBB). A description is given on how human pathogenic parasites can reach the CNS via the bloodstream either as free-living or extracellular parasites, by embolization of eggs, or within red or white blood cells when adapted to intracellular life. Molecular mechanisms are discussed by which parasites can interact with or pass across the BBB. The possible targeting of the circumventricular organs by parasites, as well as the parasites' direct entry to the brain from the nasal cavity through the olfactory nerve pathway, is also highlighted. Finally, examples are given which illustrate different mechanisms by which parasites can cause dysfunction or damage in the CNS related to toxic effects of parasite-derived molecules or to immune responses to the infection. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Multi-slice ultrasound image calibration of an intelligent skin-marker for soft tissue artefact compensation.

    Science.gov (United States)

    Masum, M A; Pickering, M R; Lambert, A J; Scarvell, J M; Smith, P N

    2017-09-06

    In this paper, a novel multi-slice ultrasound (US) image calibration of an intelligent skin-marker used for soft tissue artefact compensation is proposed to align and orient image slices in an exact H-shaped pattern. Multi-slice calibration is complex, however, in the proposed method, a phantom based visual alignment followed by transform parameters estimation greatly reduces the complexity and provides sufficient accuracy. In this approach, the Hough Transform (HT) is used to further enhance the image features which originate from the image feature enhancing elements integrated into the physical phantom model, thus reducing feature detection uncertainty. In this framework, slice by slice image alignment and calibration are carried out and this provides manual ease and convenience. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Real-time slicing algorithm for Stereolithography (STL) CAD model applied in additive manufacturing industry

    Science.gov (United States)

    Adnan, F. A.; Romlay, F. R. M.; Shafiq, M.

    2018-04-01

    Owing to the advent of the industrial revolution 4.0, the need for further evaluating processes applied in the additive manufacturing application particularly the computational process for slicing is non-trivial. This paper evaluates a real-time slicing algorithm for slicing an STL formatted computer-aided design (CAD). A line-plane intersection equation was applied to perform the slicing procedure at any given height. The application of this algorithm has found to provide a better computational time regardless the number of facet in the STL model. The performance of this algorithm is evaluated by comparing the results of the computational time for different geometry.

  11. Antibrowning and antimicrobial properties of sodium acid sulfate in apple slices.

    Science.gov (United States)

    Fan, Xuetong; Sokorai, Kimberly J B; Liao, Ching-Hsing; Cooke, Peter; Zhang, Howard Q

    2009-01-01

    There are few available compounds that can both control browning and enhance microbial safety of fresh-cut fruits. In the present study, the antibrowning ability of sodium acid sulfate (SAS) on "Granny Smith" apple slices was first investigated in terms of optimum concentration and treatment time. In a separate experiment, the apple slices were treated with water or 3% of SAS, calcium ascorbate, citric acid, or acidified calcium sulfate for 5 min. Total plate count, color, firmness, and tissue damage were assessed during a 21-d storage at 4 degrees C. Results showed that the efficacy of SAS in inhibiting browning of apple slices increased with increasing concentration. A minimum 3% of SAS was needed to achieve 14 d of shelf life. Firmness was not significantly affected by SAS at 3% or lower concentrations. Antibrowning potential of SAS was similar for all treatment times ranging from 2 to 10 min. However, SAS caused some skin discoloration of apple slices. When cut surface of apple slices were stained with a fluorescein diacetate solution, tissue damage could be observed under a microscope even though visual damage was not evident. Among the antibrowning agents tested, SAS was the most effective in inhibiting browning and microbial growth for the first 14 d. Total plate count of samples treated with 3% SAS was significantly lower than those treated with calcium ascorbate, a commonly used antibrowning agent. Our results suggested that it is possible to use SAS to control browning while inhibiting the growth of microorganisms on the apple slices if the skin damage can be minimized. Practical Application: Fresh-cut apples have emerged as one of the popular products in restaurants, schools, and food service establishments as more consumers demand fresh, convenient, and nutritious foods. Processing of fresh-cut apples induces mechanical damage to the fruit and exposes apple tissue to air, resulting in the development of undesirable tissue browning. The fresh

  12. Concept and development of measurement method of time sensitivity profile (TSP) in X-ray CT. Comparison of non-helical, single-slice helical, and multi-slice helical scans

    International Nuclear Information System (INIS)

    Tsujioka, Katsumi; Ida, Yoshihiro; Ohtsubo, Hironori; Takahashi, Yasukata; Niwa, Masayoshi

    2000-01-01

    We focused on the time element contained in a single CT image, and devised the concept of a time-sensitivity profile (TSP) describing how the time element is translated into an image. We calculated the data collection time range when the helical pitch is changed in non helical scans, single slice helical scans, and multi slice helical scans. We then calculated the time sensitivity profile (TSP) from the weighting applied when the data collection time range is translated into an image. TSP was also measured for each scanning method using our self-made moving phantom. TSPs obtained from the calculation and the experiments were very close. TSP showed interesting characteristics with each scanning method, especially in the case of multi slice helical scanning, in which TSP became shorter as helical pitch increased. We referred to the TSP's FWHM as the effective scanning time. When we conducted multi slice helical scanning at helical pitch 3, the effective scanning time increased to about 24% longer than that of a non helical scan. When we conducted multi slice helical scanning at helical pitch 5 or 6, the effective scanning time was about half that of a non helical scan. The time sensitivity profile (TSP) is a totally new concept that we consider an important element in discussing the time resolution of a CT scanner. The results of this review will provide significant data in determining the scanning parameters when scanning a moving object. (author)

  13. Handbook of Brain Connectivity

    CERN Document Server

    Jirsa, Viktor K

    2007-01-01

    Our contemporary understanding of brain function is deeply rooted in the ideas of the nonlinear dynamics of distributed networks. Cognition and motor coordination seem to arise from the interactions of local neuronal networks, which themselves are connected in large scales across the entire brain. The spatial architectures between various scales inevitably influence the dynamics of the brain and thereby its function. But how can we integrate brain connectivity amongst these structural and functional domains? Our Handbook provides an account of the current knowledge on the measurement, analysis and theory of the anatomical and functional connectivity of the brain. All contributors are leading experts in various fields concerning structural and functional brain connectivity. In the first part of the Handbook, the chapters focus on an introduction and discussion of the principles underlying connected neural systems. The second part introduces the currently available non-invasive technologies for measuring struct...

  14. Microbiological quality of sliced and block mozzarella cheese

    Directory of Open Access Journals (Sweden)

    Mariana Fontanetti Marinheiro

    2015-06-01

    Full Text Available The aim of this study was to verify the microbiological quality of mozzarella cheese sold in retail markets of Pelotas, Rio Grande do Sul, Brazil. Forty samples of mozzarella cheese were analyzed, comprising 20 samples of block cheese and 20 of sliced cheese. The cheese samples were analyzed for thermotolerant coliform counts and coagulase positive staphylococci counts, and presence of Salmonella spp and Listeria monocytogenes. The percentage of 12,5% and 5% of the sliced and block cheese samples analyzed, respectively, exceeded the microbiological standards accepted by Brazilian legislation. These results indicate the need for a better product monitoring and more concern with hygiene and sanitary practices during industrial process.

  15. Neural stem cells improve neuronal survival in cultured postmortem brain tissue from aged and Alzheimer patients

    NARCIS (Netherlands)

    Wu, L.; Sluiter, A.A.; Guo, Ho Fu; Balesar, R. A.; Swaab, D. F.; Zhou, Jiang Ning; Verwer, R. W H

    Neurodegenerative diseases are progressive and incurable and are becoming ever more prevalent. To study whether neural stem cell can reactivate or rescue functions of impaired neurons in the human aging and neurodegenerating brain, we co-cultured postmortem slices from Alzheimer patients and control

  16. Is non-invasive neuromuscular electrical stimulation effective in severe chronic neurogenic dysphagia? Reporton a post-traumatic brain injury patient.

    Science.gov (United States)

    Calabrò, Rocco Salvatore; Nibali, Valeria Conti; Naro, Antonino; Floridia, Daniela; Pizzimenti, Maria; Salmeri, Lucia; Salviera, Carlo; Bramanti, Placido

    2016-01-01

    Neurogenic dysphagia is a difficulty in swallowing induced by nervous system disease. It often causes serious complications, which are preventable if dysphagia is properly managed. There is growing debate concerning the usefulness of non-invasive neuromuscular electrical stimulation (NMES) in treating swallowing dysfunction. Aim of this study was to assess the effectiveness of Vitalstim© device, and to investigate the neurophysiological mechanisms underlying functional recovery. A 34-year-old man, affected by severe chronic dysphagia following traumatic brain injury, underwent two different intensive rehabilitation trainings, including either conventional rehabilitation alone or coupled to Vitalstim training. We evaluated patient swallowing function in two separate sessions (i.e. before and after the two trainings) by means of ad hoc swallowing function scales and electrophysiological parameters (rapid paired associative stimulation). The overall Vitalstim program was articulated in 6 weekly sessions for 6 weeks. The patient did not report any side-effect either during or following both the intensive rehabilitation trainings. We observed an important improvement in swallowing function only after Vitalstim training. In fact, the patient was eventually able to safely eat even solid food. This is the first report objectively suggesting (by means of rPAS) a correlation between the brain neuroplastic changes induced by Vitalstim and the swallowing function improvement. It is hypothesizable that Vitalstim may have targeted cortical (and maybe subcortical) brain areas that are recruited during the highly coordinated function of swallowing, and it may have thus potentiated the well-known neuroplastic changes induced by repetitive and intensive swallowing exercises, probably thanks to metaplasticity phenomena.

  17. Pre-sliced fruit in school cafeterias: children's selection and intake.

    Science.gov (United States)

    Wansink, Brian; Just, David R; Hanks, Andrew S; Smith, Laura E

    2013-05-01

    It is often assumed that children avoid fruit in school cafeterias because of higher relative prices and preferences for other foods. Interviews with children reveal that eating whole fresh fruit can be difficult for those with small mouths or braces. Older girls find whole fruits messy and unattractive to eat. To determine the effect of offering pre-sliced fruit in schools on selection and intake. Three of six schools were assigned randomly to serve apples in slices. Three control schools served apples whole. Selection, consumption, and waste of apples were measured prior to and during treatment. Cafeterias in six public middle schools in Wayne County NY in 2011. Participants included all students who purchased lunch on days when data were collected. Treatment schools were provided with a standard commercial fruit slicer, and cafeteria staff members were instructed to use it when students requested apples. Trained researchers recorded how much of each apple was consumed and how much was wasted in both control and treatment schools. Daily apple sales, percentage of an apple serving consumed per student, and percentage of an apple serving wasted per student. Data were analyzed in 2012. Schools that used fruit slicers to pre-slice fruit increased average daily apple sales by 71% compared to control schools (papples and ate more than half increased by 73% (p=0.02) at schools that served pre-sliced fruit, and the percentage that wasted half or more decreased by 48% (p=0.03). Sliced fruit is more appealing to children than whole fruit because it is easier and tidier to eat. This study applies the principle of convenience from behavioral economics and provides an example of a scalable, low-cost environmental change that promotes healthy eating and decreases waste. Copyright © 2013. Published by Elsevier Inc. on behalf of American Journal of Preventive Medicine.

  18. Influence of image slice thickness on rectal dose–response relationships following radiotherapy of prostate cancer

    International Nuclear Information System (INIS)

    Olsson, C; Thor, M; Apte, A; Deasy, J O; Liu, M; Moissenko, V; Petersen, S E; Høyer, M

    2014-01-01

    When pooling retrospective data from different cohorts, slice thicknesses of acquired computed tomography (CT) images used for treatment planning may vary between cohorts. It is, however, not known if varying slice thickness influences derived dose–response relationships. We investigated this for rectal bleeding using dose–volume histograms (DVHs) of the rectum and rectal wall for dose distributions superimposed on images with varying CT slice thicknesses. We used dose and endpoint data from two prostate cancer cohorts treated with three-dimensional conformal radiotherapy to either 74 Gy (N = 159) or 78 Gy (N = 159) at 2 Gy per fraction. The rectum was defined as the whole organ with content, and the morbidity cut-off was Grade ≥2 late rectal bleeding. Rectal walls were defined as 3 mm inner margins added to the rectum. DVHs for simulated slice thicknesses from 3 to 13 mm were compared to DVHs for the originally acquired slice thicknesses at 3 and 5 mm. Volumes, mean, and maximum doses were assessed from the DVHs, and generalized equivalent uniform dose (gEUD) values were calculated. For each organ and each of the simulated slice thicknesses, we performed predictive modeling of late rectal bleeding using the Lyman–Kutcher–Burman (LKB) model. For the most coarse slice thickness, rectal volumes increased (≤18%), whereas maximum and mean doses decreased (≤0.8 and ≤4.2 Gy, respectively). For all a values, the gEUD for the simulated DVHs were ≤1.9 Gy different than the gEUD for the original DVHs. The best-fitting LKB model parameter values with 95% CIs were consistent between all DVHs. In conclusion, we found that the investigated slice thickness variations had minimal impact on rectal dose–response estimations. From the perspective of predictive modeling, our results suggest that variations within 10 mm in slice thickness between cohorts are unlikely to be a limiting factor when pooling multi-institutional rectal dose data that include slice

  19. Dried fruit breadfruit slices by Refractive Window™ technique

    Directory of Open Access Journals (Sweden)

    Diego F. Tirado

    2016-01-01

    Full Text Available A large amount of products are dried due several reasons as preservation, weight reduction and improvement of stability. However, on the market are not offered low-cost and high quality products simultaneously. Although there are effective methods of dehydrating foods such as freeze drying, which preserves the flavor, color and vitamins, they are poor accessibility technologies. Therefore, alternative processes are required to be efficient and economical. The aim of this research was compare drying kinetics of sliced of breadfruit (Artocarpus communis using the technique of Refractive Window® (VR with the tray drying. To carry out this study, sliced of 1 and 2 mm thick were used. Refractive window drying was performed with the water bath temperature to 92 °C; and tray drying at 62 °C and an air velocity of 0.52 m/s. During the Refractive window drying technique, the moisture content reached the lower than tray drying levels. Similarly it happened with samples of 1 mm, which, having a smaller diameter reached lower moisture levels than samples 2 mm. The higher diffusivities were obtained during drying sliced VR 1 and 2 mm with coefficients of 6.13 and 3.90*10-9 m2/s respectively.

  20. Low-frequency electrical stimulation enhances the effectiveness of phenobarbital on GABAergic currents in hippocampal slices of kindled rats.

    Science.gov (United States)

    Asgari, Azam; Semnanian, Saeed; Atapour, Nafiseh; Shojaei, Amir; Moradi-Chameh, Homeira; Ghafouri, Samireh; Sheibani, Vahid; Mirnajafi-Zadeh, Javad

    2016-08-25

    Low frequency stimulation (LFS) has been proposed as a new approach in the treatment of epilepsy. The anticonvulsant mechanism of LFS may be through its effect on GABAA receptors, which are the main target of phenobarbital anticonvulsant action. We supposed that co-application of LFS and phenobarbital may increase the efficacy of phenobarbital. Therefore, the interaction of LFS and phenobarbital on GABAergic inhibitory post-synaptic currents (IPSCs) in kindled and control rats was investigated. Animals were kindled by electrical stimulation of basolateral amygdala in a semi rapid manner (12 stimulations/day). The effect of phenobarbital, LFS and phenobarbital+LFS was investigated on GABAA-mediated evoked and miniature IPSCs in the hippocampal brain slices in control and fully kindled animals. Phenobarbital and LFS had positive interaction on GABAergic currents. In vitro co-application of an ineffective pattern of LFS (100 pulses at afterdischarge threshold intensity) and a sub-threshold dose of phenobarbital (100μM) which had no significant effect on GABAergic currents alone, increased the amplitude and area under curve of GABAergic currents in CA1 pyramidal neurons of hippocampal slices significantly. Interestingly, the sub-threshold dose of phenobarbital potentiated the GABAergic currents when applied on the hippocampal slices of kindled animals which received LFS in vivo. Post-synaptic mechanisms may be involved in observed interactions. Obtained results implied a positive interaction between LFS and phenobarbital through GABAA currents. It may be suggested that a combined therapy of phenobarbital and LFS may be a useful manner for reinforcing the anticonvulsant action of phenobarbital. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Modeling Structural Brain Connectivity

    DEFF Research Database (Denmark)

    Ambrosen, Karen Marie Sandø

    The human brain consists of a gigantic complex network of interconnected neurons. Together all these connections determine who we are, how we react and how we interpret the world. Knowledge about how the brain is connected can further our understanding of the brain’s structural organization, help...... improve diagnosis, and potentially allow better treatment of a wide range of neurological disorders. Tractography based on diffusion magnetic resonance imaging is a unique tool to estimate this “structural connectivity” of the brain non-invasively and in vivo. During the last decade, brain connectivity...... has increasingly been analyzed using graph theoretic measures adopted from network science and this characterization of the brain’s structural connectivity has been shown to be useful for the classification of populations, such as healthy and diseased subjects. The structural connectivity of the brain...

  2. Local vascular CO2 reactivity in the infant brain assessed by functional MRI

    DEFF Research Database (Denmark)

    Toft, P.B.; Leth, H; Lou, H.C.

    1995-01-01

    of the brain slice investigated decreased by 1.2-2.6% per kPa change in PCO2 as a reflection of decreased cerebral blood flow during hyperventilation. Pixel-wise analysis revealed absence of vascular response in the basal ganglia, the thalamus or in the occipital region. In two adult controls, who...

  3. High-resolution brain SPECT imaging by combination of parallel and tilted detector heads.

    Science.gov (United States)

    Suzuki, Atsuro; Takeuchi, Wataru; Ishitsu, Takafumi; Morimoto, Yuichi; Kobashi, Keiji; Ueno, Yuichiro

    2015-10-01

    To improve the spatial resolution of brain single-photon emission computed tomography (SPECT), we propose a new brain SPECT system in which the detector heads are tilted towards the rotation axis so that they are closer to the brain. In addition, parallel detector heads are used to obtain the complete projection data set. We evaluated this parallel and tilted detector head system (PT-SPECT) in simulations. In the simulation study, the tilt angle of the detector heads relative to the axis was 45°. The distance from the collimator surface of the parallel detector heads to the axis was 130 mm. The distance from the collimator surface of the tilted detector heads to the origin on the axis was 110 mm. A CdTe semiconductor panel with a 1.4 mm detector pitch and a parallel-hole collimator were employed in both types of detector head. A line source phantom, cold-rod brain-shaped phantom, and cerebral blood flow phantom were evaluated. The projection data were generated by forward-projection of the phantom images using physics models, and Poisson noise at clinical levels was applied to the projection data. The ordered-subsets expectation maximization algorithm with physics models was used. We also evaluated conventional SPECT using four parallel detector heads for the sake of comparison. The evaluation of the line source phantom showed that the transaxial FWHM in the central slice for conventional SPECT ranged from 6.1 to 8.5 mm, while that for PT-SPECT ranged from 5.3 to 6.9 mm. The cold-rod brain-shaped phantom image showed that conventional SPECT could visualize up to 8-mm-diameter rods. By contrast, PT-SPECT could visualize up to 6-mm-diameter rods in upper slices of a cerebrum. The cerebral blood flow phantom image showed that the PT-SPECT system provided higher resolution at the thalamus and caudate nucleus as well as at the longitudinal fissure of the cerebrum compared with conventional SPECT. PT-SPECT provides improved image resolution at not only upper but also at

  4. Blanching, salting and sun drying of different pumpkin fruit slices.

    Science.gov (United States)

    Workneh, T S; Zinash, A; Woldetsadik, K

    2014-11-01

    The study was aimed at assessing the quality of pumpkin (Cucuribita Spp.) slices that were subjected to pre-drying treatments and drying using two drying methods (uncontrolled sun and oven) fruit accessions. Pre-drying had significant (P ≤ 0.05) effect on the quality of dried pumpkin slices. 10 % salt solution dipped pumpkin fruit slices had good chemical quality. The two-way interaction between drying methods and pre-drying treatments had significant (P ≤ 0.05) effect on chemical qualities. Pumpkin subjected to salt solution dipping treatment and oven dried had higher chemical concentrations. Among the pumpkin fruit accessions, pumpkin accession 8007 had the superior TSS, total sugar and sugar to acid ratio after drying. Among the three pre-drying treatment, salt solution dipping treatment had significant (P ≤ 0.05) effect and the most efficient pre-drying treatment to retain the quality of dried pumpkin fruits without significant chemical quality deterioration. Salt dipping treatment combined with low temperature (60 °C) oven air circulation drying is recommended to maintain quality of dried pumpkin slices. However, since direct sun drying needs extended drying time due to fluctuation in temperature, it is recommended to develop or select best successful solar dryer for use in combination with pre-drying salt dipping or blanching treatments.

  5. Automatic Solitary Lung Nodule Detection in Computed Tomography Images Slices

    Science.gov (United States)

    Sentana, I. W. B.; Jawas, N.; Asri, S. A.

    2018-01-01

    Lung nodule is an early indicator of some lung diseases, including lung cancer. In Computed Tomography (CT) based image, nodule is known as a shape that appears brighter than lung surrounding. This research aim to develop an application that automatically detect lung nodule in CT images. There are some steps in algorithm such as image acquisition and conversion, image binarization, lung segmentation, blob detection, and classification. Data acquisition is a step to taking image slice by slice from the original *.dicom format and then each image slices is converted into *.tif image format. Binarization that tailoring Otsu algorithm, than separated the background and foreground part of each image slices. After removing the background part, the next step is to segment part of the lung only so the nodule can localized easier. Once again Otsu algorithm is use to detect nodule blob in localized lung area. The final step is tailoring Support Vector Machine (SVM) to classify the nodule. The application has succeed detecting near round nodule with a certain threshold of size. Those detecting result shows drawback in part of thresholding size and shape of nodule that need to enhance in the next part of the research. The algorithm also cannot detect nodule that attached to wall and Lung Chanel, since it depend the searching only on colour differences.

  6. Adaptive slices for acquisition of anisotropic BRDF

    Czech Academy of Sciences Publication Activity Database

    Vávra, Radomír; Filip, Jiří

    (2018) ISSN 2096-0433 R&D Projects: GA ČR GA17-18407S Institutional support: RVO:67985556 Keywords : anisotropic BRDF * slice * sampling Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2018/RO/vavra-0486116.pdf

  7. Novel MRI methodology to detect human whole-brain connectivity changes after ingestion of fructose or glucose

    Science.gov (United States)

    Tsao, Sinchai; Wilkins, Bryce; Page, Kathleen A.; Singh, Manbir

    2012-03-01

    A novel MRI protocol has been developed to investigate the differential effects of glucose or fructose consumption on whole-brain functional brain connectivity. A previous study has reported a decrease in the fMRI blood oxygen level dependent (BOLD) signal of the hypothalamus following glucose ingestion, but due to technical limitations, was restricted to a single slice covering the hypothalamus, and thus unable to detect whole-brain connectivity. In another previous study, a protocol was devised to acquire whole-brain fMRI data following food intake, but only after restricting image acquisition to an MR sampling or repetition time (TR) of 20s, making the protocol unsuitable to detect functional connectivity above 0.025Hz. We have successfully implemented a continuous 36-min, 40 contiguous slices, whole-brain BOLD acquisition protocol on a 3T scanner with TR=4.5s to ensure detection of up to 0.1Hz frequencies for whole-brain functional connectivity analysis. Human data were acquired first with ingestion of water only, followed by a glucose or fructose drink within the scanner, without interrupting the scanning. Whole-brain connectivity was analyzed using standard correlation methodology in the 0.01-0.1 Hz range. The correlation coefficient differences between fructose and glucose ingestion among targeted regions were converted to t-scores using the water-only correlation coefficients as a null condition. Results show a dramatic increase in the hypothalamic connectivity to the hippocampus, amygdala, insula, caudate and the nucleus accumben for fructose over glucose. As these regions are known to be key components of the feeding and reward brain circuits, these results suggest a preference for fructose ingestion.

  8. MiR-1254 inhibits proliferation, migration and invasion of human ...

    African Journals Online (AJOL)

    MiR-1254 inhibits proliferation, migration and invasion of human brain tumour cell lines. ... The transcripts were analysed by real-time polymerase chain reaction (RT-PCR) ... Over-expression of miR- 1254 also led to significant decrease in cell ...

  9. Patient-specific metrics of invasiveness reveal significant prognostic benefit of resection in a predictable subset of gliomas.

    Directory of Open Access Journals (Sweden)

    Anne L Baldock

    Full Text Available Malignant gliomas are incurable, primary brain neoplasms noted for their potential to extensively invade brain parenchyma. Current methods of clinical imaging do not elucidate the full extent of brain invasion, making it difficult to predict which, if any, patients are likely to benefit from gross total resection. Our goal was to apply a mathematical modeling approach to estimate the overall tumor invasiveness on a patient-by-patient basis and determine whether gross total resection would improve survival in patients with relatively less invasive gliomas.In 243 patients presenting with contrast-enhancing gliomas, estimates of the relative invasiveness of each patient's tumor, in terms of the ratio of net proliferation rate of the glioma cells to their net dispersal rate, were derived by applying a patient-specific mathematical model to routine pretreatment MR imaging. The effect of varying degrees of extent of resection on overall survival was assessed for cohorts of patients grouped by tumor invasiveness.We demonstrate that patients with more diffuse tumors showed no survival benefit (P = 0.532 from gross total resection over subtotal/biopsy, while those with nodular (less diffuse tumors showed a significant benefit (P = 0.00142 with a striking median survival benefit of over eight months compared to sub-totally resected tumors in the same cohort (an 80% improvement in survival time for GTR only seen for nodular tumors.These results suggest that our patient-specific, model-based estimates of tumor invasiveness have clinical utility in surgical decision making. Quantification of relative invasiveness assessed from routinely obtained pre-operative imaging provides a practical predictor of the benefit of gross total resection.

  10. Shape determinative slice localization for patient-specific masseter modeling using shape-based interpolation

    Energy Technology Data Exchange (ETDEWEB)

    Ng, H.P. [NUS Graduate School for Integrative Sciences and Engineering (Singapore); Biomedical Imaging Lab., Agency for Science Technology and Research (Singapore); Foong, K.W.C. [NUS Graduate School for Integrative Sciences and Engineering (Singapore); Dept. of Preventive Dentistry, National Univ. of Singapore (Singapore); Ong, S.H. [Dept. of Electrical and Computer Engineering, National Univ. of Singapore (Singapore); Div. of Bioengineering, National Univ. of Singapore (Singapore); Liu, J.; Nowinski, W.L. [Biomedical Imaging Lab., Agency for Science Technology and Research (Singapore); Goh, P.S. [Dept. of Diagnostic Radiology, National Univ. of Singapore (Singapore)

    2007-06-15

    The masseter plays a critical role in the mastication system. A hybrid method to shape-based interpolation is used to build the masseter model from magnetic resonance (MR) data sets. The main contribution here is the localizing of determinative slices in the data sets where clinicians are required to perform manual segmentations in order for an accurate model to be built. Shape-based criteria were used to locate the candidates for determinative slices and fuzzy-c-means (FCM) clustering technique was used to establish the determinative slices. Five masseter models were built in our work and the average overlap indices ({kappa}) achieved is 85.2%. This indicates that there is good agreement between the models and the manual contour tracings. In addition, the time taken, as compared to manually segmenting all the slices, is significantly lesser. (orig.)

  11. Shape determinative slice localization for patient-specific masseter modeling using shape-based interpolation

    International Nuclear Information System (INIS)

    Ng, H.P.; Foong, K.W.C.; Ong, S.H.; Liu, J.; Nowinski, W.L.; Goh, P.S.

    2007-01-01

    The masseter plays a critical role in the mastication system. A hybrid method to shape-based interpolation is used to build the masseter model from magnetic resonance (MR) data sets. The main contribution here is the localizing of determinative slices in the data sets where clinicians are required to perform manual segmentations in order for an accurate model to be built. Shape-based criteria were used to locate the candidates for determinative slices and fuzzy-c-means (FCM) clustering technique was used to establish the determinative slices. Five masseter models were built in our work and the average overlap indices (κ) achieved is 85.2%. This indicates that there is good agreement between the models and the manual contour tracings. In addition, the time taken, as compared to manually segmenting all the slices, is significantly lesser. (orig.)

  12. 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...

  13. Imaging by the SSFSE single slice method at different viscosities of bile

    International Nuclear Information System (INIS)

    Kubo, Hiroya; Usui, Motoki; Fukunaga, Kenichi; Yamamoto, Naruto; Ikegami, Toshimi

    2001-01-01

    The single shot fast spin echo single thick slice method (single slice method) is a technique that visualizes the water component alone using a heavy T 2 . However, this method is considered to be markedly affected by changes in the viscosity of the material because a very long TE is used, and changes in the T 2 value, which are related to viscosity, directly affect imaging. In this study, we evaluated the relationship between the effects of TE and the T 2 value of bile in the single slice method and also examined the relationship between the signal intensity of bile on T 1 - and T 2 -weighted images and imaging by MR cholangiography (MRC). It was difficult to image bile with high viscosities at a usual effective TE level of 700-1,500 ms. With regard to the relationship between the signal intensity of bile and MRC imaging, all T 2 values of the bile samples showing relatively high signal intensities on the T 1 -weighted images suggested high viscosities, and MRC imaging of these bile samples was poor. In conclusion, MRC imaging of bile with high viscosities was poor with the single slice method. Imaging by the single slice method alone of bile showing a relatively high signal intensity on T 1 -weighted images should be avoided, and combination with other MRC sequences should be used. (author)

  14. Transcranial magnetic stimulation and the human brain

    Science.gov (United States)

    Hallett, Mark

    2000-07-01

    Transcranial magnetic stimulation (TMS) is rapidly developing as a powerful, non-invasive tool for studying the human brain. A pulsed magnetic field creates current flow in the brain and can temporarily excite or inhibit specific areas. TMS of motor cortex can produce a muscle twitch or block movement; TMS of occipital cortex can produce visual phosphenes or scotomas. TMS can also alter the functioning of the brain beyond the time of stimulation, offering potential for therapy.

  15. [Virtual bronchoscopy in the child using multi-slice CT: initial clinical experiences].

    Science.gov (United States)

    Kirchner, J; Laufer, U; Jendreck, M; Kickuth, R; Schilling, E M; Liermann, D

    2000-01-01

    Virtual bronchoscopy of the pediatric patient has been reported to be more difficult because of artifacts due to breathing or motion. We demonstrate the benefit of the accelerated examination based on multislice spiral CT (MSCT) in the pediatric patient which has not been reported so far. MSCT (tube voltage 120 kV, tube current 110 mA, 4 x 1 mm Slice thickness, 500 ms rotation time, Pitch 6) was performed on a CT scanner of the latest generation (Volume Zoom, Siemens Corp. Forchheim, Germany). In totally we examined 11 patients (median age 48 months, range 2-122 months) suspected of having tracheoesophageal fistula (n = 2), tracheobronchial narrowing (n = 8) due to intrinsic or extrinsic factors or injury of the bronchial system (n = 1). In all patients we obtained sufficient data for 3D reconstruction avoiding general anesthesia. 6/11 examinations were described to be without pathological finding. A definite diagnosis was obtained in 10 patients. Virtual bronchoscopy could avoid other invasive diagnostic examination in 8/11 patients (73%). Helical CT provides 3D-reconstruction and virtual bronchoscopy in the newborn as well as the infant. It avoids additional diagnostic bronchoscopy in a high percentage of all cases.

  16. Alteration of tricarboxylic acid cycle metabolism in rat brain slices by halothane

    International Nuclear Information System (INIS)

    Cheng, S.C.; Brunner, E.A.

    1978-01-01

    Metabolism of [2- 14 C] pyruvate, [1- 14 C] acetate and [5- 14 C] citrate in rat cerebral cortex slices was studied in the presence of halothane. Metabolites assayed include acetylcholine (ACh), citrate, glutamate, glutamineγ-aminobutyrate (GABA) and aspartate. The trichloroacetic acid soluble extract, the trichloracetic acid insoluble precipitate and its lipid extract were also studied. In control experiments, pyruvate preferentially labelled ACh, citrate, glutamate, GABA and aspartate. Acetate labelled ACh, but to a lesser extent than pyruvate. Acetate also labelled lipids and glutamine. Citrate labelled lipids but not ACh and served as a preferential precursor for glutamine. These data support a three-compartment model for cerebral tricarboxylic acid cycle metabolism. Halothane caused increases in GABA and aspartate contents and a decrease in ACh content. It has no effect on the contents of citrate, glutamate and glutamine. Halothane preferentially inhibited the metabolic transfer of radioactivity from pyruvate into almost all metabolites, an effect probably not related to pyruvate permeability. This is interpreted as halothane depression of the large metabolic compartment which includes the nerve endings. Halothane increased the metabolic transfer of radioactivity from acetate into lipids but did not alter such a transfer into the trichloroacetic acid extract. Halothane increased the metabolic transfer of radioactivity from citrate into the trichloroacetic acid precipitate, lipids and especially glutamine. Transfer of citrate radioactivity into GABA was somewhat decreased. The differential effects of halothane on acetate and citrate utilization suggest that the small metabolic compartment should be subdivided. Therefore, at least three metabolic compartments are demonstrated. Halothane did not interfere with the dicarboxylic acid portion of the tricarboxylic acid cycle. (author)

  17. Cryopreservation of Precision-cut Tissue Slices for Application in Drug Metabolism Research

    NARCIS (Netherlands)

    Graaf, Inge Anne Maria de

    2002-01-01

    The research described in this thesis had two important aims. The first was to determine whether tissue slices could be used as an in vitro tool to predict the in vivo metabolism of new drugs. The second aim was to find a manner to store tissue slices for longer time periods by cryopreservation.

  18. Ditection of coronary artery disease: accuracy of 64- slice computed tomography versus converntional invasive angiography

    Directory of Open Access Journals (Sweden)

    Taghizadeh M

    2008-11-01

    Full Text Available "nBackground: Multislice computed tomography (MSCT is a noninvasive method of detecting coronary artery disease (CAD. The purpose of the present study was to investigate the accuracy of 64-slice MSCT (64-MSCT in daily practice, without patient selection. "nMethods: Sixty-four consecutive suspected CAD patients underwent both 64-MSCT and quantitative coronary angiography (QCA. The CT system The mean time span between MSCT and QCA was 7.2±3.9 days. For the 64-MSCT, detection or exclusion of CAD, defined as one or more areas of >50% stenosis within major epicardial coronary arteries, the sensitivity, specificity, diagnostic accuracy, positive predictive value (PPV, and negative predictive value (NPV were evaluated both per patient and per segment. "nResults: Sixty-one of the 64 coronary CT angiograms (95% were of diagnostic image quality. QCA showed significant CAD in 64% (39/61 of the patients, with the other 36% (22/61 showing nonsignificant disease or no disease. Sensitivity, specificity, accuracy, PPV, and NPV of 64-MSCT per patient were 92%, 86%, 90%, 92% and 96%, respectively. By the per-segment analysis, 695 of 791 coronary artery segments were assessable (88%. Of these, 64-MSCT showed a sensitivity of 80%, specificity of 92%, accuracy of 90%, PPV of 65%, and NPV of 96%, respectively, in detecting CAD. "nConclusions: Both per patient and per segment analyses for coronary 64-MSCT showed a higher diagnostic accuracy than QCA. This suggests 64-MSCT should primarily be used for risk stratification on a per patient basis as a noninvasive gate-keeper diagnostic method.

  19. Velocity slice imaging for dissociative electron attachment

    Science.gov (United States)

    Nandi, Dhananjay; Prabhudesai, Vaibhav S.; Krishnakumar, E.; Chatterjee, A.

    2005-05-01

    A velocity slice imaging method is developed for measuring the angular distribution of fragment negative ions arising from dissociative electron attachment (DEA) to molecules. A low energy pulsed electron gun, a pulsed field ion extraction, and a two-dimensional position sensitive detector consisting of microchannel plates and a wedge-and-strip anode are used for this purpose. Detection and storage of each ion separately for its position and flight time allows analysis of the data offline for any given time slice, without resorting to pulsing the detector bias. The performance of the system is evaluated by measuring the angular distribution of O- from O2 and comparing it with existing data obtained using conventional technique. The capability of this technique in obtaining forward and backward angular distribution data is shown to have helped in resolving one of the existing problems in the electron scattering on O2.

  20. Automatic registration of imaging mass spectrometry data to the Allen Brain Atlas transcriptome

    Science.gov (United States)

    Abdelmoula, Walid M.; Carreira, Ricardo J.; Shyti, Reinald; Balluff, Benjamin; Tolner, Else; van den Maagdenberg, Arn M. J. M.; Lelieveldt, B. P. F.; McDonnell, Liam; Dijkstra, Jouke

    2014-03-01

    Imaging Mass Spectrometry (IMS) is an emerging molecular imaging technology that provides spatially resolved information on biomolecular structures; each image pixel effectively represents a molecular mass spectrum. By combining the histological images and IMS-images, neuroanatomical structures can be distinguished based on their biomolecular features as opposed to morphological features. The combination of IMS data with spatially resolved gene expression maps of the mouse brain, as provided by the Allen Mouse Brain atlas, would enable comparative studies of spatial metabolic and gene expression patterns in life-sciences research and biomarker discovery. As such, it would be highly desirable to spatially register IMS slices to the Allen Brain Atlas (ABA). In this paper, we propose a multi-step automatic registration pipeline to register ABA histology to IMS- images. Key novelty of the method is the selection of the best reference section from the ABA, based on pre-processed histology sections. First, we extracted a hippocampus-specific geometrical feature from the given experimental histological section to initially localize it among the ABA sections. Then, feature-based linear registration is applied to the initially localized section and its two neighbors in the ABA to select the most similar reference section. A non-rigid registration yields a one-to-one mapping of the experimental IMS slice to the ABA. The pipeline was applied on 6 coronal sections from two mouse brains, showing high anatomical correspondence, demonstrating the feasibility of complementing biomolecule distributions from individual mice with the genome-wide ABA transcriptome.

  1. Demonstration of the pulmonary interlobar fissures on multiplanar reformatted images with 64-slices spiral CT

    International Nuclear Information System (INIS)

    Wang Yafei; Chen Yerong; Shan Xiuhong; Tang Zhiyang; Ni Enzhen; Huang Hao; Wu Shuchun

    2009-01-01

    Objective: To determine the optimal orientation and slice thickness of reformatted images to visualize the interlobar fissures on multiplanar reformation (MPR) images and to recommend MPR imaging protocal for visualizing interlobar fissures in clinical practise. Methods: 64-slices CT scans of chest were obtained in 300 patients without pulmonary diseases. Axial, sagittal and coronal images were reformatted at 1, 2, 3, 7 mm slice thickness respectively from the raw volume data. Three experienced radiologists evaluated all of the MPR images in the lung window and compared the differences in visualization of the interlohar fissures among the three reformatted orientations and at the different slice thicknesses with Fisher test and Friedman test. Results: Fissures on sagittal MPR images using 1, 2, 3, and 7 mm reformatted slice thickness appeared as a fine line and the preference value analysis showed the MPR images with a 3 mm reformatted slice thickness is the best for visualizing the interlobar fissure. Compared to the sagittal orientation, the coronal was not as good and the axial was the worst among the three orientations. The coronal images with a 3 mm reformatted slice thickness were slightly inferior to sagittal images. The right horizontal fissures were observed as a fine line in all coronal image in 94.0% (282)of cases and in some of the images in 6.0% (18) of cases, the right oblique fissures were displayed as a fine line in coronal images in 2.3% (7) of cases and in some images in 85.0% (255) of cases, the left oblique fissures were displayed as a fine line in some coronal images in 35.7% (107) of cases and displayed as a coarse line in 64.3% (193) of cases. On axial MPR images using 3 mm reformation slice thickness, the right oblique fissures and the left oblique fissures were displayed as a fine line in some axial images in 79.3% (238) and 81.0% (243) of cases respectively, none of the images showed horizontal fissures as a fine line. There was

  2. A STUDY ON PERITUMORAL BRAIN EDEMA AROUND MENINGIOMAS BY MRI AND CONTRAST CT

    NARCIS (Netherlands)

    GO, KG; KAMMAN, RL; WILMINK, JT; MOOYAART, EL

    1994-01-01

    In the present study upon 9 meningiomas, the volume of peritumoral brain edema was calculated by integration of the cross-sectional edematous areas on serial MRI slices. It was zero in 3 cases and ranged from 11 to 176.4 ml in the other cases. There was disruption of the cortex in all cases, ranging

  3. Respiratory sinus arrhythmia as a non-invasive index of ′brain-heart′ interaction in stress

    Directory of Open Access Journals (Sweden)

    Ingrid Tonhajzerova

    2016-01-01

    Full Text Available Respiratory sinus arrhythmia (RSA is accepted as a peripheral marker of cardiac-linked parasympathetic regulation. According to polyvagal theory, the RSA is also considered as the index of emotion regulation. The neurovisceral integration model posits that parasympathetic modulation of the heart marked by RSA is related to complex nervous regulation associated with emotional and cognitive processing. From this perspective, high resting RSA amplitude associated with a greater withdrawal during stressors and subsequent recovery could represent a flexible and adaptive physiological response system to a challenge. Conversely, low resting RSA accompanied by an inadequate reactivity to stress might reflect maladaptive regulatory mechanisms. The RSA reactivity is different with various types of stressors: while the RSA decreases to cognitive tasks indicating a vagal withdrawal, the RSA magnitude increases to emotional challenge indicating an effective cognitive processing of emotional stimuli. The RSA reactivity to stress could have important implications for several mental disorders, e.g. depressive or anxiety disorder. It seems that the study of the RSA, as a non-invasive index of ′brain-heart′ communication, could provide important information on the pathway linked to mental and physical health.

  4. Live cell imaging of cytosolic NADH/NAD+ ratio in hepatocytes and liver slices.

    Science.gov (United States)

    Masia, Ricard; McCarty, William J; Lahmann, Carolina; Luther, Jay; Chung, Raymond T; Yarmush, Martin L; Yellen, Gary

    2018-01-01

    Fatty liver disease (FLD), the most common chronic liver disease in the United States, may be caused by alcohol or the metabolic syndrome. Alcohol is oxidized in the cytosol of hepatocytes by alcohol dehydrogenase (ADH), which generates NADH and increases cytosolic NADH/NAD + ratio. The increased ratio may be important for development of FLD, but our ability to examine this question is hindered by methodological limitations. To address this, we used the genetically encoded fluorescent sensor Peredox to obtain dynamic, real-time measurements of cytosolic NADH/NAD + ratio in living hepatocytes. Peredox was expressed in dissociated rat hepatocytes and HepG2 cells by transfection, and in mouse liver slices by tail-vein injection of adeno-associated virus (AAV)-encoded sensor. Under control conditions, hepatocytes and liver slices exhibit a relatively low (oxidized) cytosolic NADH/NAD + ratio as reported by Peredox. The ratio responds rapidly and reversibly to substrates of lactate dehydrogenase (LDH) and sorbitol dehydrogenase (SDH). Ethanol causes a robust dose-dependent increase in cytosolic NADH/NAD + ratio, and this increase is mitigated by the presence of NAD + -generating substrates of LDH or SDH. In contrast to hepatocytes and slices, HepG2 cells exhibit a relatively high (reduced) ratio and show minimal responses to substrates of ADH and SDH. In slices, we show that comparable results are obtained with epifluorescence imaging and two-photon fluorescence lifetime imaging (2p-FLIM). Live cell imaging with Peredox is a promising new approach to investigate cytosolic NADH/NAD + ratio in hepatocytes. Imaging in liver slices is particularly attractive because it allows preservation of liver microanatomy and metabolic zonation of hepatocytes. NEW & NOTEWORTHY We describe and validate a new approach for measuring free cytosolic NADH/NAD + ratio in hepatocytes and liver slices: live cell imaging with the fluorescent biosensor Peredox. This approach yields dynamic, real

  5. MR image-guided portal verification for brain treatment field

    International Nuclear Information System (INIS)

    Yin, F.-F.; Gao, Q.H.; Xie, H.; Nelson, D.F.; Yu, Y.; Kwok, W.E.; Totterman, S.; Schell, M.C.; Rubin, P.

    1996-01-01

    Purpose/Objective: Although MR images have been extensively used for the treatment planning of radiation therapy of cancers, especially for brain cancers, they are not effectively used for the portal verification due to lack of bone/air information in MR images and geometric distortions. Typically, MR images are utilized through correlation with CT images, and this procedure is usually very labor and time consuming. For many brain cancer patients to be treated using conventional external beam radiation, MR images with proper distortion correction provide sufficient information for treatment planning and dose calculation, and a projection images may be generated for each specific treatment port and to be used as a reference image for treatment verification. The question is how to transfer anatomical features in MR images to the projection image as landmarks which could be correlated automatically to those in the portal image. The goal of this study is to generate digitally reconstructed projection images from MR brain images with some important anatomical features (brain contour, skull and gross tumor) as well as their relative locations to be used as references for the development of computerized portal verification scheme. Materials/Methods: Compared to conventional digital reconstructed radiograph from CT images, generation of digitally reconstructed projection images from MR images is heavily involved with pixel manipulation of MR images to correlate information from two types of images (MR, portal x-ray images) which are produced based on totally different imaging principles. Initially a wavelet based multi-resolution adaptive thresholding method is used to segment the skull slice-by-slice in MR brain axial images, and identified skull pixels are re-assigned to relatively higher intensities so that projection images will have comparable grey-level information as that in typical brain portal images. Both T1- and T2-weighted images are utilized to eliminate fat

  6. Confocal fluorescence microscopy for minimal-invasive tumor diagnosis

    International Nuclear Information System (INIS)

    Zenzinger, M.; Bille, J.

    2000-01-01

    The goal of the project ''stereotactic laser-neurosurgery'' is the development of a system for careful and minimal-invasive resection of brain tumors with ultrashort laser pulses through a thin probe. A confocal laser-scanning-microscope is integrated in the probe. In this paper, the simulation of its optical properties by a laboratory setup and the expansion by the ability for fluorescence microscopy are reported. For a valuation of the imaging properties, the point-spread-function in three dimensions and the axial depth-transfer-function were measured and thus, among other things, the resolving power and the capacity for depth discrimination were analysed. The microscope will enable intra-operative detection of tumor cells by the method of immunofluorescence. As a first model of the application in the brain, cell cultures, that fluorescein-labelled antibodies were bound to specifically, were used in this work. Due to the fluorescence signal, it was possible to detect and identify clearly the areas that had been marked in this manner, proving the suitability of the setup for minimal-invasive tumor diagnosis. (orig.)

  7. Analysis of aliasing artifacts in 16-slice helical CT

    International Nuclear Information System (INIS)

    Chen Wei; Liu Jingkang; Ou Xiaoguang; Li Wenzheng; Liao Weihua; Yan Ang

    2006-01-01

    Objective: To recognize the features of aliasing artifacts on CT images, and to investigate the effects of imaging parameters on the magnitude of this artifacts. Methods: An adult dry skull was placed in a plastic water-filled container and scanned with a PHILIPS 16-slice helical CT. All the acquired transaxial images by using several different acquisition or reconstruction parameters were examined for comparative assessment of the aliasing artifacts. Results: The aliasing artifacts could be seen in most instances and characterized as the spokewise patterns emanating from the edges of high contrast structure as its radius varies sharply in the longitudinal direction. The images that scanned with pitch of 0.3, 0.6 and 0.9, respectively, showed aliasing artifacts, and its severities increased with pitches escalated (detector combination 16 x 1.5, reconstruction thickness 2 mm); There were more significant aliasing artifacts on the images reconstructed with 0.8 mm slice width compared with 1-mm slice width, and no aliasing artifacts were observed on the images reconstructed with 2-mm slice width (detector combination 16 x 0.75, pitch 0.6); No artifacts were perceived on the images scanned with detector combination 16 x 0.75, while presented evidently with the use of detector combination 16 x 1.5 (pitch 0.6, reconstruction thickness 2 mm); The degrees of aliasing artifacts were unaltered when reconstruction interval and tube current changed. Conclusions: Aliasing artifacts are caused by undersampling. When the operator choose the thinner sampling thickness, lower pitch and a much wider reconstruction thickness judiciously, aliasing artifacts could be effectively mitigated or suppressed. (authors)

  8. Influence of image slice thickness on rectal dose-response relationships following radiotherapy of prostate cancer

    Science.gov (United States)

    Olsson, C.; Thor, M.; Liu, M.; Moissenko, V.; Petersen, S. E.; Høyer, M.; Apte, A.; Deasy, J. O.

    2014-07-01

    When pooling retrospective data from different cohorts, slice thicknesses of acquired computed tomography (CT) images used for treatment planning may vary between cohorts. It is, however, not known if varying slice thickness influences derived dose-response relationships. We investigated this for rectal bleeding using dose-volume histograms (DVHs) of the rectum and rectal wall for dose distributions superimposed on images with varying CT slice thicknesses. We used dose and endpoint data from two prostate cancer cohorts treated with three-dimensional conformal radiotherapy to either 74 Gy (N = 159) or 78 Gy (N = 159) at 2 Gy per fraction. The rectum was defined as the whole organ with content, and the morbidity cut-off was Grade ≥2 late rectal bleeding. Rectal walls were defined as 3 mm inner margins added to the rectum. DVHs for simulated slice thicknesses from 3 to 13 mm were compared to DVHs for the originally acquired slice thicknesses at 3 and 5 mm. Volumes, mean, and maximum doses were assessed from the DVHs, and generalized equivalent uniform dose (gEUD) values were calculated. For each organ and each of the simulated slice thicknesses, we performed predictive modeling of late rectal bleeding using the Lyman-Kutcher-Burman (LKB) model. For the most coarse slice thickness, rectal volumes increased (≤18%), whereas maximum and mean doses decreased (≤0.8 and ≤4.2 Gy, respectively). For all a values, the gEUD for the simulated DVHs were ≤1.9 Gy different than the gEUD for the original DVHs. The best-fitting LKB model parameter values with 95% CIs were consistent between all DVHs. In conclusion, we found that the investigated slice thickness variations had minimal impact on rectal dose-response estimations. From the perspective of predictive modeling, our results suggest that variations within 10 mm in slice thickness between cohorts are unlikely to be a limiting factor when pooling multi-institutional rectal dose data that include slice thickness

  9. Impact of whey protein coating incorporated with Bifidobacterium and Lactobacillus on sliced ham properties.

    Science.gov (United States)

    Odila Pereira, Joana; Soares, José; J P Monteiro, Maria; Gomes, Ana; Pintado, Manuela

    2018-05-01

    Edible coatings/films with functional ingredients may be a solution to consumers' demands for high-quality food products and an extended shelf-life. The aim of this work was to evaluate the antimicrobial efficiency of edible coatings incorporated with probiotics on sliced ham preservation. Coatings was developed based on whey protein isolates with incorporation of Bifidobacterium animalis Bb-12® or Lactobacillus casei-01. The physicochemical analyses showed that coating decreased water and weight loss on the ham. Furthermore, color analysis showed that coated sliced ham, exhibited no color change, comparatively to uncoated slices. The edible coatings incorporating the probiotic strains inhibited detectable growth of Staphylococcus spp., Pseudomonas spp., Enterobacteriaceae and yeasts/molds, at least, for 45days of storage at 4°C. The sensory evaluation demonstrated that there was a preference for the sliced coated ham. Probiotic bacteria viable cell numbers were maintained at ca. 10 8 CFU/g throughout storage time, enabling the slice of ham to act as a suitable carrier for the beneficial bacteria. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Characterization of the effects of serotonin on the release of [3H]dopamine from rat nucleus accumbens and striatal slices

    International Nuclear Information System (INIS)

    Nurse, B.; Russell, V.A.; Taljaard, J.J.

    1988-01-01

    The effect of serotonin agonists on the depolarization (K+)-induced, calcium-dependent, release of [ 3 H]dopamine (DA) from rat nucleus accumbens and striatal slices was investigated. Serotonin enhanced basal 3 H overflow and reduced K+-induced release of [ 3 H]DA from nucleus accumbens slices. The effect of serotonin on basal 3 H overflow was not altered by the serotonin antagonist, methysergide, or the serotonin re-uptake blocker, chlorimipramine, but was reversed by the DA re-uptake carrier inhibitors nomifensine and benztropine. With the effect on basal overflow blocked, serotonin did not modulate K+-induced release of [ 3 H]DA in the nucleus accumbens or striatum. The serotonin agonists, quipazine (in the presence of nomifensine) and 5-methoxytryptamine, did not significantly affect K+-induced release of [ 3 H]DA in the nucleus accumbens. This study does not support suggestions that serotonin receptors inhibit the depolarization-induced release of dopamine in the nucleus accumbens or striatum of the rat brain. The present results do not preclude the possibility that serotonin may affect the mesolimbic reward system at a site which is post-synaptic to dopaminergic terminals in the nucleus accumbens

  11. Pitch dependence of longitudinal sampling and aliasing effects in multi-slice helical computed tomography (CT)

    International Nuclear Information System (INIS)

    La Riviere, Patrick J.; Pan Xiaochuan

    2002-01-01

    In this work, we investigate longitudinal sampling and aliasing effects in multi-slice helical CT. We demonstrate that longitudinal aliasing can be a significant, complicated, and potentially detrimental effect in multi-slice helical CT reconstructions. Multi-slice helical CT scans are generally undersampled longitudinally for all pitches of clinical interest, and the resulting aliasing effects are spatially variant. As in the single-slice case, aliasing is shown to be negligible at the isocentre for circularly symmetric objects due to a fortuitous aliasing cancellation phenomenon. However, away from the isocentre, aliasing effects can be significant, spatially variant, and highly pitch dependent. This implies that measures more sophisticated than isocentre slice sensitivity profiles are needed to characterize longitudinal properties of multi-slice helical CT systems. Such measures are particularly important in assessing the question of whether there are preferred pitches in helical CT. Previous analyses have generally focused only on isocentre sampling patterns, and our more global analysis leads to somewhat different conclusions than have been reached before, suggesting that pitches 3, 4, 5, and 6 are favourable, and that half-integer pitches are somewhat suboptimal. (author)

  12. Slicing Method for curved façade and window extraction from point clouds

    Science.gov (United States)

    Iman Zolanvari, S. M.; Laefer, Debra F.

    2016-09-01

    Laser scanning technology is a fast and reliable method to survey structures. However, the automatic conversion of such data into solid models for computation remains a major challenge, especially where non-rectilinear features are present. Since, openings and the overall dimensions of the buildings are the most critical elements in computational models for structural analysis, this article introduces the Slicing Method as a new, computationally-efficient method for extracting overall façade and window boundary points for reconstructing a façade into a geometry compatible for computational modelling. After finding a principal plane, the technique slices a façade into limited portions, with each slice representing a unique, imaginary section passing through a building. This is done along a façade's principal axes to segregate window and door openings from structural portions of the load-bearing masonry walls. The method detects each opening area's boundaries, as well as the overall boundary of the façade, in part, by using a one-dimensional projection to accelerate processing. Slices were optimised as 14.3 slices per vertical metre of building and 25 slices per horizontal metre of building, irrespective of building configuration or complexity. The proposed procedure was validated by its application to three highly decorative, historic brick buildings. Accuracy in excess of 93% was achieved with no manual intervention on highly complex buildings and nearly 100% on simple ones. Furthermore, computational times were less than 3 sec for data sets up to 2.6 million points, while similar existing approaches required more than 16 hr for such datasets.

  13. Acetyl-L-carnitine improves aged brain function.

    Science.gov (United States)

    Kobayashi, Satoru; Iwamoto, Machiko; Kon, Kazuo; Waki, Hatsue; Ando, Susumu; Tanaka, Yasukazu

    2010-07-01

    The effects of acetyl-L-carnitine (ALCAR), an acetyl derivative of L-carnitine, on memory and learning capacity and on brain synaptic functions of aged rats were examined. Male Fischer 344 rats were given ALCAR (100 mg/kg bodyweight) per os for 3 months and were subjected to the Hebb-Williams tasks and AKON-1 task to assess their learning capacity. Cholinergic activities were determined with synaptosomes isolated from brain cortices of the rats. Choline parameters, the high-affinity choline uptake, acetylcholine (ACh) synthesis and depolarization-evoked ACh release were all enhanced in the ALCAR group. An increment of depolarization-induced calcium ion influx into synaptosomes was also evident in rats given ALCAR. Electrophysiological studies using hippocampus slices indicated that the excitatory postsynaptic potential slope and population spike size were both increased in ALCAR-treated rats. These results indicate that ALCAR increases synaptic neurotransmission in the brain and consequently improves learning capacity in aging rats.

  14. 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...

  15. Reduction of acrylamide formation in potato slices during frying

    DEFF Research Database (Denmark)

    Pedreschi, Franco; Kaack, K.; Granby, Kit

    2004-01-01

    and 40 min; 90degreesC for 2 and 9 min); (iii) immersed in citric acid solutions of different concentrations (10 and 20 g/l) for half an hour. Glucose and asparagine concentration was determined in potato slices before frying, whereas acrylamide content was determined in the resultant fried potato chips...... on average 76% and 68% of the glucose and asparagine content compared to the control. Potato slices blanched at 50degreesC for 70 min surprisingly had a very low acrylamide content (28 mum/kg) even when they were fried at 190degreesC. Potato immersion in citric acid solutions of 10 and 20 g/l reduced...

  16. HUMAN LIVER SLICES EXPRESS THE SAME LIDOCAINE BIOTRANSFORMATION RATE AS ISOLATED HUMAN HEPATOCYTES

    NARCIS (Netherlands)

    OLINGA, P; MEIJER, DKF; SLOOFF, MJH; GROOTHUIS, GMM; Merema, M.T.

    1993-01-01

    In order to investigate whether liver slices are a valuable tool for the assessment of drug metabolism in human liver, we compared the phase I metabolism of lidocaine in human liver slices and hepatocytes prepared from three human livers. Lidocaine is mainly metabolised to monoethylglycinexylidide

  17. Does slice thickness affect diagnostic performance of 64-slice CT coronary angiography in stable and unstable angina patients with a positive calcium score?

    Energy Technology Data Exchange (ETDEWEB)

    Meijs, Matthijs F.L.; Vos, Alexander M. de; Cramer, Maarten J.; Doevendans, Pieter A.; Vries, Jan J.J. de; Rutten, Annemarieke; Budde, Ricardo P.J.; Prokop, Mathias (Dept. of Radiology, Univ. Medical Center Utrecht, Utrecht (Netherlands)), e-mail: m.meijs@umcutrecht.nl; Meijboom, W. Bob; Feyter, Pim J. de (Dept. of Cardiology, Erasmus Medical Center, Rotterdam (Netherlands))

    2010-05-15

    Background: Coronary calcification can lead to over-estimation of the degree of coronary stenosis. Purpose: To evaluate whether thinner reconstruction thickness improves the diagnostic performance of 64-slice CT coronary angiography (CTCA) in angina patients with a positive calcium score. Material and Methods: We selected 20 scans from a clinical study comparing CTCA to conventional coronary angiography (CCA) in stable and unstable angina patients based on a low number of motion artifacts and a positive calcium score. All images were acquired at 64 x 0.625 mm and each CTCA scan was reconstructed at slice thickness/increment 0.67 mm/0.33 mm, 0.9 mm/0.45 mm, and 1.4 mm/0.7 mm. Two reviewers blinded for CCA results independently evaluated the scans for the presence of significant coronary artery disease (CAD) in three randomly composed series, with =2 weeks in between series. The diagnostic performance of CTCA was compared for the different slice thicknesses using a pooled analysis of both reviewers. Significant CAD was defined as >50% diameter narrowing on quantitative CCA. Image noise (standard deviation of CT numbers) was measured in all scans. Inter-observer variability was assessed with kappa. Results: Significant CAD was present in 8% of 304 available segments. Median total Agatston calcium score was 181.8 (interquartile range 34.9-815.6). Sensitivity at 0.67 mm, 0.9 mm, and 1.4 mm slice thickness was 70% (95% confidence interval 57-83%), 74% (62-86%), and 70% (57-83%), respectively. Specificity was 85% (82-88%), 84% (81-87%), and 84% (81-87%), respectively. The positive predictive value was 30 (21-38%), 29 (21-37%), and 28 (20-36%), respectively. The negative predictive value was 97% (95-98%), 97% (96-99%), and 97% (96-99%), respectively. Kappa for inter-observer agreement was 0.56, 0.58, and 0.59. Noise decreased from 32.9 HU at 0.67 mm, to 23.2 HU at 1.4 mm (P<0.001). Conclusion: Diagnostic performance of CTCA in angina patients with a positive calcium score

  18. Evaluating Changes to Blood-Brain Barrier Integrity in Brain Metastasis over Time and after Radiation Treatment

    Directory of Open Access Journals (Sweden)

    Donna H. Murrell

    2016-06-01

    Full Text Available INTRODUCTION: The incidence of brain metastasis due to breast cancer is increasing, and prognosis is poor. Treatment is challenging because the blood-brain barrier (BBB limits efficacy of systemic therapies. In this work, we develop a clinically relevant whole brain radiotherapy (WBRT plan to investigate the impact of radiation on brain metastasis development and BBB permeability in a murine model. We hypothesize that radiotherapy will decrease tumor burden and increase tumor permeability, which could offer a mechanism to increase drug uptake in brain metastases. METHODS: Contrast-enhanced magnetic resonance imaging (MRI and high-resolution anatomical MRI were used to evaluate BBB integrity associated with brain metastases due to breast cancer in the MDA-MB-231-BR-HER2 model during their natural development. Novel image-guided microirradiation technology was employed to develop WBRT treatment plans and to investigate if this altered brain metastatic growth or permeability. Histology and immunohistochemistry were performed on whole brain slices corresponding with MRI to validate and further investigate radiological findings. RESULTS: Herein, we show successful implementation of microirradiation technology that can deliver WBRT to small animals. We further report that WBRT following diagnosis of brain metastasis can mitigate, but not eliminate, tumor growth in the MDA-MB-231-BR-HER2 model. Moreover, radiotherapy did not impact BBB permeability associated with metastases. CONCLUSIONS: Clinically relevant WBRT is not curative when delivered after MRI-detectable tumors have developed in this model. A dose of 20 Gy in 2 fractions was not sufficient to increase tumor permeability such that it could be used as a method to increase systemic drug uptake in brain metastasis.

  19. In vitro imaging of coronary artery stents: Are there differences between 16- and 64-slice CT scanners?

    International Nuclear Information System (INIS)

    Wolf, Florian; Feuchtner, Gudrun M.; Homolka, Peter; Langenberger, Herbert; Stadler, Alfred; Bader, Till R.; Weber, Michael; Lammer, Johannes; Loewe, Christian

    2008-01-01

    Purpose: To compare the performance of 64-slice with 16-slice CT scanners for the in vitro evaluation of coronary artery stents. Methods and materials: Twelve different coronary artery stents were placed in the drillings of a combined heart and chest phantom, which was scanned with a 16- and 64-slice CT scanner. Coronal reformations were evaluated for artificial lumen narrowing, intraluminal attenuation values, and false widening of the outer stent diameter as an indicator of artifacts outside the stent. Results: Mean artificial lumen narrowing was not significantly different between the 16- and 64-slice CT scanner (44% versus 39%; p = 0.408). The differences between the Hounsfield Units (HU) measurements inside and outside the stents were significantly lower (p = 0.001) with 64- compared to 16-slice CT. The standard deviation of the HU measurements inside the stents was significantly (p = 0.002) lower with 64- than with 16-slice CT. Artifacts outside the stents were not significantly different between the scanners (p = 0.866). Conclusion: Visualization of the in-stent lumen is improved with 64-slice CT when compared with 16-slice CT as quantified by significantly lesser intraluminal image noise and less artificial rise in intraluminal HU measurement, which is the most important parameter for the evaluation of stent patency in vivo

  20. Imaging by the SSFSE single slice method at different viscosities of bile

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Hiroya; Usui, Motoki; Fukunaga, Kenichi; Yamamoto, Naruto; Ikegami, Toshimi [Kawasaki Hospital, Kobe (Japan)

    2001-11-01

    The single shot fast spin echo single thick slice method (single slice method) is a technique that visualizes the water component alone using a heavy T{sub 2}. However, this method is considered to be markedly affected by changes in the viscosity of the material because a very long TE is used, and changes in the T{sub 2} value, which are related to viscosity, directly affect imaging. In this study, we evaluated the relationship between the effects of TE and the T{sub 2} value of bile in the single slice method and also examined the relationship between the signal intensity of bile on T{sub 1}- and T{sub 2}-weighted images and imaging by MR cholangiography (MRC). It was difficult to image bile with high viscosities at a usual effective TE level of 700-1,500 ms. With regard to the relationship between the signal intensity of bile and MRC imaging, all T{sub 2} values of the bile samples showing relatively high signal intensities on the T{sub 1}-weighted images suggested high viscosities, and MRC imaging of these bile samples was poor. In conclusion, MRC imaging of bile with high viscosities was poor with the single slice method. Imaging by the single slice method alone of bile showing a relatively high signal intensity on T{sub 1}-weighted images should be avoided, and combination with other MRC sequences should be used. (author)