The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform

Caroline Rae - One of the best experts on this subject based on the ideXlab platform.

  • Brain gene expression, metabolism, and bioenergetics: interrelationships in murine models of cerebral and noncerebral malaria
    FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 2004
    Co-Authors: Caroline Rae, William A. Bubb, James A. Mcquillan, Sapan B. Parekh, Silvia Weiser, Vladimir J. Balcar, Anna M. Hansen, Helen J. Ball, Nicholas H. Hunt
    Abstract:

    Malaria infection can cause cerebral symptoms without parasite invasion of Brain tissue. We examined the relationships between Brain Biochemistry, bioenergetics, and gene expression in murine models of cerebral (Plasmodium berghei ANKA) and noncerebral (P. berghei K173) malaria using multinuclear NMR spectroscopy, neuropharmacological approaches, and real-time RT-PCR. In cerebral malaria caused by P. berghei ANKA infection, we found biochemical changes consistent with increased glutamatergic activity and decreased flux through the Krebs cycle, followed by increased production of the hypoxia markers lactate and alanine. This was accompanied by compromised Brain bioenergetics. There were few significant changes in expression of mRNA for metabolic enzymes or transporters or in the rate of transport of glutamate or glucose. However, in keeping with a role for endogenous cytokines in malaria cerebral pathology, there was significant up-regulation of mRNAs for TNF-α, interferon-γ, and lymphotoxin. These changes...

  • Abnormalities in Brain Biochemistry associated with lack of dystrophin: studies of the mdx mouse
    Neuromuscular disorders : NMD, 2002
    Co-Authors: Caroline Rae, Julian L Griffin, Duncan H Blair, John H. F. Bothwell, William A. Bubb, Annie Maitland, Stewart I. Head
    Abstract:

    Biochemical abnormalities have been reported in dystrophin-deficient muscle of boys with Duchenne (severe Xp21) muscular dystrophy or in the murine (mdx) model of the disease. These abnormalities include altered energy metabolism and responses to osmotic shock. In contrast, the situation in Brain is less well understood and it is probable that dystrophin is playing a different role (or roles) in this organ. In this study we conclude that the elevation in choline-containing compounds reported in mdx Brain is confined to cerebellum and hippocampus in older (> 6 months) mice. We report alterations in glucose metabolism in mdx Brain under normal, awake conditions, and a reduced response of Brain metabolism to the gamma-aminobutyric acid(A) receptor agonist muscimol. Using Brain cortical slices we found no difference in the response of dystrophic tissue to hypoosmotic shock, but increased, substrate-dependent oxygen consumption rates at low oxygen partial pressures.

  • Brain Biochemistry in Duchenne muscular dystrophy: A 1H magnetic resonance and neuropsychological study
    Journal of the neurological sciences, 1998
    Co-Authors: Caroline Rae, Richard B. Scott, Campbell H. Thompson, Ruth Dixon, Ishbel Dumughn, Graham J. Kemp, Alison Male, Michael Pike, Peter Styles, George K. Radda
    Abstract:

    Abstract Duchenne muscular dystrophy (DMD) is a progressive muscle disorder associated with an intellectual deficit which is non-progressive. We obtained localised 1H magnetic resonance spectra from the left frontal lobe and left cerebellum of 15 boys with DMD (mean age 106 months±32) and 15 similarly aged control boys (mean age 115 months±31); all boys underwent a battery of neuropsychological tests. We found a significant (P 0.80) revealed a significant difference in ability on the MAT (P

  • Brain Biochemistry in Williams syndrome Evidence for a role of the cerebellum in cognition
    Neurology, 1998
    Co-Authors: Caroline Rae, Campbell H. Thompson, Ruth Dixon, Peter Styles, Annette Karmiloff-smith, M A Lee, Julia Grant, Andrew M. Blamire, G. K. Radda
    Abstract:

    Objective: To determine what biochemical changes may occur in the Brain in Williams syndrome (WS) and whether these changes may be related to the cognitive deficits. Background: WS is a rare, congenital disorder with a characteristic physical, linguistic, and behavioral phenotype with known cognitive deficits. Methods: We obtained 31 P magnetic resonance spectra (MRS) from a region consisting of mostly frontal and parietal lobe of 14 patients with WS (age, 8 to 37 years) and 48 similarly-aged controls. 1 H MRS (27 cm 3 ) localized to the left cerebellum obtained from the WS cohort were compared with those from 16 chronological age- and sex-matched normal controls. A battery of cognitive tests were administered to all subjects undergoing 1 H MRS. Results: WS Brains exhibited significant biochemical abnormalities. All 31 P MRS ratios containing the phosphomonoester (PME) peak were significantly altered in WS, suggesting that PME is significantly decreased. Ratios of choline-containing compounds and creatine-containing compounds to N-acetylaspartate (Cho/NA and Cre/NA) were significantly elevated in the cerebellum in WS cf. controls, whereas the ratio of Cho/Cre was not altered. This suggests a decrease in the neuronal marker N-acetylaspartate in the cerebellum. Significant correlations were found between the cerebellar ratios Cho/NA and Cre/NA and the ability of all subjects at various neuropsychological tests, including Verbal and Performance IQ, British Picture Vocabulary Scale, Ravens Progressive Matrices, and Inspection Time. Conclusions: The correlations can be interpreted in two ways: 1) Our sampling of cerebellar Biochemistry reflects a measure of "global" cerebral Biochemistry and is unrelated to cerebellar function, or 2) The relations indicate that cerebellar neuronal integrity is a requirement (on a developmental time scale or in real-time) for ability on a variety of cognitive tests.

K. R. R. Krishnan - One of the best experts on this subject based on the ideXlab platform.

  • Reproducibility of high spatial resolution proton magnetic resonance spectroscopic imaging in the human Brain
    Magnetic resonance in medicine, 1996
    Co-Authors: H. C. Charles, François Lazeyras, Larry A. Tupler, K. R. R. Krishnan
    Abstract:

    The application of proton (1H) magnetic resonance spectroscopic imaging (MRSI) allows for noninvasive, localized analyses of Brain Biochemistry; however, minimal work has been devoted to the evaluation of 1H MRSI reproducibility. This study examined the reproducibility of 1H MRSI from five normal subjects on two occasions, separated by 10 days. Reproducibility of the MR signal was evaluated in the context of automated shimming, automated processing, and accurate subject repositioning. Reliability measures for physicochemical indices (choline moieties, creatine, N-acetylaspartate, and myo-inositol) were moderately concordant across repeat studies. Gain variation and repositioning results were excellent. It has been concluded that 1H MRSI reproducibility is adequate for serial studies of Brain metabolism.

N. Van Bruggen - One of the best experts on this subject based on the ideXlab platform.

  • Applications of magnetic resonance spectroscopy and diffusion-weighted imaging to the study of Brain Biochemistry and pathology
    Trends in neurosciences, 1993
    Co-Authors: Risto A. Kauppinen, Stephen R. Williams, A.l. Busza, N. Van Bruggen
    Abstract:

    The first practical demonstration that nuclear magnetic resonance (NMR) spectroscopy could be applied to the study of Brain Biochemistry in vivo came in 1980, with the studies of the rat Brain using a surface coil. Since then the technique has been rapidly and extensively developed into a versatile, non-invasive tool for the investigation of various aspects of Brain Biochemistry, physiology and disease. NMR is non-destructive and can be used to examine a wide variety of samples, ranging from localized regions within the whole Brain in humans or animals, through tissue preparations (perfused organ, tissue slices and homogenates), to isolated cells and aqueous solutions, such as tissue extracts. 31P and 1H NMR spectra deriving from endogenous compounds of the Brain in situ allow assessment of tissue metabolites and provide information about high-energy phosphates, lactate, certain amino acids, intracellular pH and ionic concentrations. Exogenous substrates or probes labelled with stable isotopes can also be introduced into the Brain and used to monitor metabolism. Animal models of Brain diseases have given some impetus to rapid progress in clinical NMR spectroscopy and also magnetic imaging techniques. The purpose of this article is to highlight the type of information available from these NMR techniques, and to present this in a neuroscience context, emphasizing the biochemical, physiological and pathological information that can be obtained using these methods.

Edson Bor-seng-shu - One of the best experts on this subject based on the ideXlab platform.

  • Cerebral Microdialysis in Traumatic Brain Injury and Subarachnoid Hemorrhage: State of the Art
    Neurocritical Care, 2014
    Co-Authors: Marcelo Lima Oliveira, Ana Carolina Kairalla, Erich Talamoni Fonoff, Raquel Chacon Ruiz Martinez, Manoel Jacobsen Teixeira, Edson Bor-seng-shu
    Abstract:

    Cerebral microdialysis (CMD) is a laboratory tool that provides on-line analysis of Brain Biochemistry via a thin, fenestrated, double-lumen dialysis catheter that is inserted into the interstitium of the Brain. A solute is slowly infused into the catheter at a constant velocity. The fenestrated membranes at the tip of the catheter permit free diffusion of molecules between the Brain interstitium and the perfusate, which is subsequently collected for laboratory analysis. The major molecules studied using this method are glucose, lactate, pyruvate, glutamate, and glycerol. The collected substances provide insight into the neurochemical features of secondary injury following traumatic Brain injury (TBI) and subarachnoid hemorrhage (SAH) and valuable information about changes in Brain metabolism within a short time frame. In this review, the authors detail the CMD technique and its associated markers and then describe pertinent findings from the literature about the clinical application of CMD in TBI and SAH.

Graham N. George - One of the best experts on this subject based on the ideXlab platform.

  • In situ biospectroscopic investigation of rapid ischemic and postmortem induced biochemical alterations in the rat Brain.
    ACS chemical neuroscience, 2014
    Co-Authors: Mark J. Hackett, Carter J. Britz, Phyllis G. Paterson, Helen Nichol, Ingrid J. Pickering, Graham N. George
    Abstract:

    Rapid advances in imaging technologies have pushed novel spectroscopic modalities such as Fourier transform infrared spectroscopy (FTIR) and X-ray absorption spectroscopy (XAS) at the sulfur K-edge to the forefront of direct in situ investigation of Brain Biochemistry. However, few studies have examined the extent to which sample preparation artifacts confound results. Previous investigations using traditional analyses, such as tissue dissection, homogenization, and biochemical assay, conducted extensive research to identify biochemical alterations that occur ex vivo during sample preparation. In particular, altered metabolism and oxidative stress may be caused by animal death. These processes were a concern for studies using biochemical assays, and protocols were developed to minimize their occurrence. In this investigation, a similar approach was taken to identify the biochemical alterations that are detectable by two in situ spectroscopic methods (FTIR, XAS) that occur as a consequence of ischemic cond...