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Howlett DR, Bate ST, Collier S, Lawman A, Chapman T, Ashmeade T, Marshall I, Anderson PJB, Philpott KL, Richardson JC, Hille CJ. Characterisation of amyloid-induced inflammatory responses in the rat retina. Exp Brain Res 2011; 214:185-97. [PMID: 21850448 DOI: 10.1007/s00221-011-2819-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 07/27/2011] [Indexed: 11/29/2022]
Abstract
Amyloid-induced inflammation is thought to play a critical and early role in the pathophysiology of Alzheimer's disease. As such, robust models with relevant and accessible compartments that provide a means of assessing anti-inflammatory agents are essential for the development of therapeutic agents. In the present work, we have characterised the induction of inflammation in the rat retina following intravitreal administration of amyloid-beta protein (Aβ). Histology and mRNA endpoints in the retina demonstrate Aβ1-42-, but not Aβ42-1-, induced inflammatory responses characterised by increases in markers for microglia and astrocytes (ionised calcium-binding adaptor molecule 1 (iba-1), GFAP and nestin) and increases in mRNA for inflammatory cytokines and chemokines such as IL1-β, MIP1α and TNFα. Likewise, analysis of vitreal cytokines also revealed increases in inflammatory cytokines and chemokines, including IL1-β, MIP1α and MCP1, induced by Aβ1-42 but not Aβ42-1. This profile of pro-inflammatory gene and protein expression is consistent with that observed in the Alzheimer's disease brain and suggest that this preclinical model may provide a useful relevant tool in the development of anti-inflammatory approaches directed towards Alzheimer's disease therapy.
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Kavuru MS, Malur A, Marshall I, Barna BP, Meziane M, Huizar I, Dalrymple H, Karnekar R, Thomassen MJ. An open-label trial of rituximab therapy in pulmonary alveolar proteinosis. Eur Respir J 2011; 38:1361-7. [PMID: 21478218 DOI: 10.1183/09031936.00197710] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Rituximab, a monoclonal antibody directed against the B-lymphocyte antigen CD20, has shown promise in several autoimmune disorders. Pulmonary alveolar proteinosis (PAP) is an autoimmune disorder characterised by autoantibodies to granulocyte-macrophage colony-stimulating factor (GM-CSF). An open-label, proof-of-concept phase II clinical trial was conducted in 10 PAP patients. The intervention consisted of two intravenous infusions of rituximab (1,000 mg) 15 days apart. Bronchoalveolar lavage (BAL) fluid and peripheral blood samples were collected. The primary outcome was improvement in arterial blood oxygenation. Both arterial oxygen tension and alveolar-arterial oxygen tension difference in room air improved in seven out of the nine patients completing the study. Lung function and high-resolution computed tomography scans, which were secondary outcomes, also improved. Peripheral blood CD19+ B-lymphocytes decreased from mean ± sem 15 ± 2% to <0.05% (n = 10) 15 days post-therapy. This decrease persisted for 3 months in all patients; at 6 months, CD19+ B-cells were detected in four out of seven patients (5 ± 2%). Total anti-GM-CSF immunoglobulin (Ig)G levels from baseline to 6 months were decreased in BAL fluids (n = 8) but unchanged in sera (n = 9). In this PAP cohort: 1) rituximab was well-tolerated and effectively ameliorated lung disease; and 2) reduction in anti-GM-CSF IgG levels in the lung correlated with disease changes, suggesting that disease pathogenesis is related to autoantibody levels in the target organ.
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Hawkins J, Harrison DC, Ahmed S, Davis RP, Chapman T, Marshall I, Smith B, Mead TL, Medhurst A, Giblin GMP, Hall A, Gonzalez MI, Richardson J, Hussain I. Dynamics of Aβ42 reduction in plasma, CSF and brain of rats treated with the γ-secretase modulator, GSM-10h. NEURODEGENER DIS 2011; 8:455-64. [PMID: 21389687 DOI: 10.1159/000324511] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 01/21/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Allosteric modulation of γ-secretase is an attractive therapeutic approach for the treatment of Alzheimer's disease. We recently identified a novel γ-secretase modulator, GSM-10h, which effectively lowers Aβ42 production in cells and in amyloid precursor protein transgenic mice. OBJECTIVE Here, we describe the in vivo characterization of GSM-10h in a model of endogenous Aβ production. METHODS Rats were administered orally with GSM-10h, and the effect on Aβ levels in peripheral and central compartments was determined. In addition, the effect of GSM-10h on Notch processing was assessed. RESULTS Acute administration of GSM-10h to rats causes a dose-dependent decrease in the level of Aβ42 in plasma, CSF and brain, with little effect on the level of Aβ40 in these compartments. The magnitude of Aβ42 lowering in the CSF and brain was further enhanced upon sub-chronic administration of GSM-10h. No deleterious effect on Notch processing was evident in either of these studies. To further explore the dynamics of Aβ42 reduction in peripheral and CNS compartments, a time course study was conducted. In all compartments, the decrease in Aβ42 was greatest at 6 h after administration of GSM-10h. This decrease in Aβ42 was maintained for 9-15 h, after which time Aβ42 levels returned to baseline levels. Encouragingly, no rebound in Aβ42 levels beyond baseline levels was observed. CONCLUSIONS These findings support the γ-secretase modulator profile of GSM-10h, and highlight the utility of the rat for assessing the pre-clinical efficacy of γ-secretase modulators.
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Hussain I, Harrison DC, Hawkins J, Chapman T, Marshall I, Facci L, Ahmed S, Brackenborough K, Skaper SD, Mead TL, Smith BB, Giblin GM, Hall A, Gonzalez MI, Richardson JC. TASTPM Mice Expressing Amyloid Precursor Protein and Presenilin-1 Mutant Transgenes Are Sensitive to γ-Secretase Modulation and Amyloid-β 42 Lowering by GSM-10h. NEURODEGENER DIS 2011; 8:15-24. [DOI: 10.1159/000313903] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 04/15/2010] [Indexed: 11/19/2022] Open
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Gradin V, Gountouna VE, Waiter G, Ahearn TS, Brennan D, Condon B, Marshall I, McGonigle DJ, Murray AD, Whalley H, Cavanagh J, Hadley D, Lymer K, McIntosh A, Moorhead TW, Job D, Wardlaw J, Lawrie SM, Steele JD. Between- and within-scanner variability in the CaliBrain study n-back cognitive task. Psychiatry Res 2010; 184:86-95. [PMID: 20880670 DOI: 10.1016/j.pscychresns.2010.08.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2009] [Revised: 08/15/2010] [Accepted: 08/19/2010] [Indexed: 10/19/2022]
Abstract
Psychiatric neuroimaging techniques are likely to improve understanding of the brain in health and disease, but studies tend to be small, based in one imaging centre and of unclear generalisability. Multicentre studies have great appeal but face problems if functional magnetic resonance imaging (fMRI) data from different centres are to be combined. Fourteen healthy volunteers had two brain scans on different days at three scanners. Considerable effort was first made to use similar scanning sequences and standardise task implementation across centres. The n-back cognitive task was used to investigate between- and within-scanner reproducibility and reliability. Both the functional imaging and behavioural results were in good accord with the existing literature. We found no significant differences in the activation/deactivation maps between scanners, or between repeat visits to the same scanners. Between- and within-scanner reproducibility and reliability was very similar. However, the smoothness of images from the scanners differed, suggesting that smoothness equalization might further reduce inter-scanner variability. Our results for the n-back task suggest it is possible to acquire fMRI data from different scanners which allows pooling across centres, when the same field strength scanners are used and scanning sequences and paradigm implementations are standardised.
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Marshall I. Computational simulations and experimental studies of 3D phase-contrast imaging of fluid flow in carotid bifurcation geometries. J Magn Reson Imaging 2010; 31:928-34. [PMID: 20373438 DOI: 10.1002/jmri.22096] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To evaluate the use of computational fluid dynamic (CFD)-based magnetic resonance imaging (MRI) simulations to predict the image appearance and velocity measurement of fluid flow in human carotid bifurcation geometries, and to compare the results with images from experimental MRI studies. MATERIALS AND METHODS Simulated particle paths were calculated from available CFD datasets of normal and moderately stenosed carotid bifurcation geometries. An MRI simulator based on the spin isochromat method was used to generate images corresponding to a 3D phase-contrast sequence with velocity encoding in three orthogonal directions. The resulting images were compared qualitatively with experimental MRI scans of the corresponding physical models. RESULTS The simulations predicted the main features observed in experimental studies, such as the low image intensity in regions of complex flow and the position and bright appearance of the jet in the stenosed bifurcation. Simulated velocity images also agreed well with experimental results. The effects of sequence parameters such as repetition time (TR) and echo time (TE) were readily demonstrated by the simulations. CONCLUSION CFD-based MRI simulations can be used to predict the appearance of MRI images of regions of physiological flow, and may be useful in the development of improved pulse sequences for flow measurement.
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Karaszewski B, Thomas RGR, Chappell FM, Armitage PA, Carpenter TK, Lymer GKS, Dennis MS, Marshall I, Wardlaw JM. Brain choline concentration. Early quantitative marker of ischemia and infarct expansion? Neurology 2010; 75:850-6. [PMID: 20819997 DOI: 10.1212/wnl.0b013e3181f11bf1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Better prediction of tissue prognosis in acute stroke might improve treatment decisions. We hypothesized that there are metabolic ischemic disturbances measurable noninvasively by proton magnetic resonance spectroscopy ((1)H MRS) that occur earlier than any structural changes visible on diffusion-tensor imaging (DTI), which may therefore serve for territorial identification of tissue at risk. METHODS We performed multivoxel (1)H MRS plus DTI within a maximum of 26 hours, and DTI at 3-7 days, after ischemic stroke. We compared choline, lactate, N-acetylaspartate, and creatine concentrations in normal-appearing voxels that became infarcted (infarct expansion) with normal-appearing voxels around the infarct that remained "healthy" (nonexpansion) on follow-up DTI. Each infarct expansion voxel was additionally classified as either complete infarct expansion (infarcted tissue on follow-up DTI covered > or =50% of the voxel) or partial infarct expansion (<50% of voxel). RESULTS In 31 patients (NIH Stroke Scale score 0-28), there were 108 infarct nonexpansion voxels and 113 infarct expansion voxels (of which 80 were complete expansion and 33 partial expansion voxels). Brain choline concentration increased for each change in expansion category from nonexpansion, via partial expansion to complete expansion (2,423, 3,843, 4,158 IU; p < 0.05). Changes in lactate, N-acetylaspartate, and creatine concentrations in expansion category were insignificant although for lactate there was a tendency to such association. CONCLUSIONS Choline concentration measurable with (1)H MRS was elevated in peri-ischemic normal-appearing brain that became infarcted by 3-7 days. The degree of elevation was associated with the amount of infarct expansion. (1)H MRS might identify DTI-normal-appearing tissue at risk of conversion to infarction in early stroke.
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Chakrabarti S, Marshall I. Another unusual presentation of McCune Albright syndrome with fibrous dysplasia, unilateral testicular enlargement, and testicular microlithiasis. J Pediatr Endocrinol Metab 2010; 23:513-5. [PMID: 20662352 DOI: 10.1515/jpem.2010.084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We report on a 9-year-old boy with atypical McCune Albright syndrome who presented with polyostotic fibrous dysplasia, unilateral testicular enlargement without signs of sexual precocity, and bilateral testicular microlithiasis on sonography. This is the first report of a patient with an atypical form of MAS presenting with unilateral testicular enlargement not associated with sexual precocity, and with testicular microlithiasis.
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Papadopoulos D, Rundle J, Patel R, Marshall I, Stretton J, Eaton R, Richardson JC, Gonzalez MI, Philpott KL, Reynolds R. FTY720 ameliorates MOG-induced experimental autoimmune encephalomyelitis by suppressing both cellular and humoral immune responses. J Neurosci Res 2010; 88:346-59. [PMID: 19658199 DOI: 10.1002/jnr.22196] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
FTY720, an oral sphingosine 1-phosphate (S1P) receptor modulator, has shown efficacy in phase II trials in patients with relapsing-remitting multiple sclerosis (MS). Although this molecule is thought to immunosuppress by inhibiting lymphocyte egress from the lymph nodes, the full spectrum of FTY720's actions has not yet been uncovered. In this study, we investigated the effects of FTY720 treatment on disease severity and histopathology of MOG-induced experimental autoimmune encephalomyelitis (EAE) in the dark agouti (DA) rat, a model that closely mimics several features of MS. The effects of FTY720 on T-cell subsets, anti-MOG antibody production, and mRNA expression of a number of cytokines and other genes were also examined. Commencement of treatment before disease onset prevented the appearance of clinical disease. Therapeutic treatment after established disease reduced clinical scores and substantially attenuated inflammation, demyelination, and axon loss. EAE suppression was associated with a reduction in all measured T-cell subsets in blood and spleen and a significant decrease in serum IgG(2a) levels. However, in the lymph nodes, all T-cell subsets except for naïve T cells and recent thymic emigrants remained unaffected. In addition, FTY720 treatment led to a significant inhibition in interferon-gamma, inducible nitric oxide synthase, and glial cell line-derived neurotrophic factor mRNA expression in the MOG-EAE spinal cord. In conclusion, our findings indicate that FTY720-mediated S1P receptor modulation ameliorates chronic relapsing MOG-EAE by suppressing both cellular and humoral immune responses.
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Cvoro V, Marshall I, Armitage PA, Bastin ME, Carpenter T, Rivers CS, Dennis MS, Wardlaw JM. MR diffusion and perfusion parameters: relationship to metabolites in acute ischaemic stroke. J Neurol Neurosurg Psychiatry 2010; 81:185-91. [PMID: 19687025 DOI: 10.1136/jnnp.2008.168393] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Magnetic resonance (MR) diffusion and perfusion imaging are used to identify ischaemic penumbra, but there are few comparisons with neuronal loss and ischaemia in vivo. The authors compared N-acetyl aspartate (NAA, found in intact neurons) and lactate (anaerobic metabolism) with diffusion/perfusion parameters. METHODS The authors prospectively recruited patients with acute ischaemic stroke and performed MR diffusion tensor, perfusion (PWI) and proton chemical shift spectroscopic imaging (CSI). We superimposed a 0.5 cm voxel grid on the diffusion-weighted images (DWI) and classified voxels as 'definitely abnormal,' 'possibly abnormal' or normal on DWI appearance, and 'mismatch' for voxels in DWI/PWI mismatch areas. The authors compared metabolite (NAA, lactate), perfusion and apparent diffusion coefficient (ADC) values in each voxel type. RESULTS NAA differentiated 'definitely' from 'possibly abnormal,' and 'possibly abnormal' from 'mismatch' (both comparisons p<0.01) voxels, but not 'mismatch' from 'normal' voxels. Lactate was highest in 'definitely abnormal,' and progressively lower in 'possibly abnormal,' 'mismatch,' than 'normal' voxels (all differences p<0.01). There was no correlation between NAA and ADC or PWI values, but high lactate correlated with low ADC (Spearman r=-0.41, p=0.02) and prolonged mean transit time (Spearman r=0.42, p=0.02). CONCLUSION ADC and mean transit time indicate the presence of ischaemia (lactate) but not cumulative total neuronal damage (NAA) in acute ischaemic stroke, suggesting that caution is required if using ADC and PWI parameters to differentiate salvageable from non-salvageable tissue. Further refinement of the DWI/PWI concept is required prior to more widespread use.
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Auchus R, Witchel S, Leight K, Aisenberg J, Azziz R, Bachega T, Baker L, Baratz A, Baskin L, Berenbaum S, Breault D, Cerame B, Conway G, Eugster E, Fracassa S, Gearhart J, Geffner M, Harris K, Hurwitz R, Katz A, Kalro B, Lee P, Alger Lin G, Loechner K, Marshall I, Merke D, Migeon C, Miller W, Nenadovich T, Oberfield S, Pass K, Poppas D, Lloyd-Puryear M, Quigley C, Riepe F, Rink R, Rivkees S, Sandberg D, Schaeffer T, Schlussel R, Schneck F, Seely E, Snyder D, Speiser P, Therrell B, VanRyzin C, Vogiatzi M, Wajnrajch M, White P, Zuckerman A. Guidelines for the Development of Comprehensive Care Centers for Congenital Adrenal Hyperplasia: Guidance from the CARES Foundation Initiative. INTERNATIONAL JOURNAL OF PEDIATRIC ENDOCRINOLOGY 2010. [DOI: 10.1186/1687-9856-2010-275213] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Macritchie KAN, Lloyd AJ, Bastin ME, Vasudev K, Gallagher P, Eyre R, Marshall I, Wardlaw JM, Ferrier IN, Moore PB, Young AH. White matter microstructural abnormalities in euthymic bipolar disorder. Br J Psychiatry 2010; 196:52-8. [PMID: 20044661 DOI: 10.1192/bjp.bp.108.058586] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Abnormal diffusion parameters are reported in specific brain regions and white matter tracts in bipolar disorder. AIMS To investigate whether these abnormalities are generalised, and thus evident in large regions of white matter. METHOD Diffusion parameters were measured at several regions in the corpus callosum and in deep/periventricular white matter in 28 currently euthymic patients with bipolar disorder and controls. White matter hyperintensity loads were assessed. RESULTS Comparing the whole data-sets using the sign test, in the group with bipolar disorder, mean diffusivity was greater at all 15 sites (P<0.001) and fractional anisotropy was reduced at 13 (P<0.01). The effect of diagnosis was significant for callosal mean diffusivity and fractional anisotropy and for deep/periventricular mean diffusivity (MANCOVA). Comparing individual regions (Mann-Whitney U-test), prefrontal and periventricular mean diffusivity were significantly increased; callosal and occipital fractional anisotropy were significantly reduced. Former substance use and lithium were possible confounding factors. Periventricular white matter hyperintensities were associated with significantly increased periventricular mean diffusivity in individuals with bipolar disorder. CONCLUSIONS Generalised white matter microstructural abnormalities may exist in bipolar disorder, possibly exacerbated by past substance use and ameliorated by lithium.
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Schwindack C, Siminotto E, Meyer M, McNamara A, Marshall I, Wardlaw JM, Whittle IR. Real-time functional magnetic resonance imaging (rt-fMRI) in patients with brain tumours: preliminary findings using motor and language paradigms. Br J Neurosurg 2009; 19:25-32. [PMID: 16147579 DOI: 10.1080/02688690500089621] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Functional MRI (fMRI) shows areas of the brain that are active during a task, but the standard approach (offline analysis after the imaging has finished) precludes tailoring of the imaging to the individual patient, e.g. for assessing normal function around an individual lesion. The aims of the study were to explore the technical feasibility of acquiring functional images in real-time (rt-fMRI), develop the necessary software interfaces and protocols for image acquisition, and to compare images of functional activation acquired in real-time with the standard offline statistical parametric method in patients with solitary brain tumours. Patients with a solitary supratentorial lesion were studied. The rt-fMRI paradigms were sequential finger opposition, ankle movement and language function (correct recognition of grammatically violated sentences). Datasets were analysed using AFNI software (National Institute of Mental Health, Bethesda, Maryland, USA) for the real-time analysis and SPM99 (Functional Imaging Laboratory, University College, London, UK) for the offline analysis. From 11 patients, useful data were obtained in nine. The finger tapping task produced most consistent activation between real-time and offline analysis with good anatomic localization to the primary motor cortex contralateral to the tapping finger. Ankle movement produced weaker activation and correlation with real-time analysis. For the language task the offline analysis provided reproducible activation patterns, but the real-time method showed no activation at the chosen threshold of p = 0.001. Tumourous areas of brain did not show any activation with either method of analysis during any task. rt-fMRI is feasible and could be a valuable functional evaluation tool in the planning of surgery for tumours in motor regions of the brain. Further paradigm development is required for evaluation of language, and possibly other more complex executive functions.
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Marshall I, Maccormick I, Sellar R, Whittle I. Assessment of factors affecting MRI measurement of intracranial volume changes and elastance index. Br J Neurosurg 2009; 22:389-97. [DOI: 10.1080/02688690801911598] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Karaszewski B, Wardlaw JM, Marshall I, Cvoro V, Wartolowska K, Haga K, Armitage PA, Bastin ME, Dennis MS. Early brain temperature elevation and anaerobic metabolism in human acute ischaemic stroke. Brain 2009; 132:955-64. [PMID: 19346327 DOI: 10.1093/brain/awp010] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Early after acute ischaemic stroke, elevation of brain temperature might augment tissue metabolic rate and conversion of ischaemic but viable tissue to infarction. This might explain the observed link between pyrexia, severe stroke and poor outcome. We tested this hypothesis by measuring brain temperature and lactate concentration with multi-voxel magnetic resonance spectroscopic imaging across the acute ischaemic stroke lesion and normal brain as determined on diffusion imaging. We compared patterns of lactate concentration (reported in 'institutional units') and temperature elevation in diffusion lesion core, potential penumbra, ipsilateral and contralateral normal brain and with stroke severity. Amongst 40 patients with moderate to severe acute stroke imaged up to 26 h after onset, lactate concentration was highest in the ischaemic lesion core (42 versus 26 units in potential penumbra, P < 0.05), whereas temperature was highest in the potential penumbra (37.7 versus 37.3 degrees C in lesion core, P < 0.05). Neither sub-regional temperature nor lactate concentration correlated with stroke severity. With increasing time after stroke, ipsilateral brain temperature did not change, but contralateral hemisphere temperature was higher in patients scanned at later times; lactate remained elevated in the lesion core, but declined in potential penumbral and ipsilateral normal tissue at later times. We conclude that early brain temperature elevation after stroke is not directly related to lactate concentration, therefore augmented metabolism is unlikely to explain the relationship between early pyrexia, severe stroke and poor outcome. Early brain temperature elevation may result from different mechanisms to those which raise body temperature after stroke. Further studies are required to determine why early brain temperature elevation is highest in potential penumbral tissue.
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Cvoro V, Wardlaw JM, Marshall I, Armitage PA, Rivers CS, Bastin ME, Carpenter TK, Wartolowska K, Farrall AJ, Dennis MS. Associations between diffusion and perfusion parameters, N-acetyl aspartate, and lactate in acute ischemic stroke. Stroke 2009; 40:767-72. [PMID: 19150873 DOI: 10.1161/strokeaha.108.525626] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE In acute ischemic stroke, the amount of neuronal damage in hyperintense areas on MR diffusion imaging (DWI) is unclear. We used spectroscopic imaging to measure N-acetyl aspartate (NAA, a marker of normal neurons) and lactate (a marker of ischemia) to compare with diffusion and perfusion values in the diffusion lesion in acute ischemic stroke. METHODS We recruited patients with acute ischemic stroke prospectively and performed MR diffusion weighted (DWI), perfusion, and spectroscopic imaging. We coregistered the images, outlined the visible diffusion lesion, and extracted metabolite, perfusion, and apparent diffusion coefficient (ADC) values from the diffusion lesion. RESULTS 42 patients were imaged, from 1.5 to 24 hours after stroke. In the DWI lesion, although NAA was reduced, there was no correlation between NAA and ADC or perfusion values. However, raised lactate correlated with reduced ADC (Spearman rho=0.32, P=0.04) and prolonged mean transit time (MTT, rho=0.31, P=0.04). Increasing DWI lesion size was associated with lower NAA and higher lactate (rho=-0.44, P=0.003; rho=0.49, P=0.001 respectively); NAA fell with increasing times to imaging (rho=-0.3, P=0.03), but lactate did not change. CONCLUSIONS Although larger confirmatory studies are needed, the correlation of ADC and MTT with lactate but not NAA suggests that ADC and MTT are better markers of the presence of ischemia than of cumulative neuronal loss. Further studies should define more precisely the rate of neuronal loss and relationship to diffusion and perfusion parameters with respect to the depth and duration of ischemia.
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Munoz Maniega S, Cvoro V, Chappell FM, Armitage PA, Marshall I, Bastin ME, Wardlaw JM. Changes in NAA and lactate following ischemic stroke: A serial MR spectroscopic imaging study. Neurology 2008; 71:1993-9. [DOI: 10.1212/01.wnl.0000336970.85817.4a] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Diaczok D, Romero C, Zunich J, Marshall I, Radovick S. A novel dominant negative mutation of OTX2 associated with combined pituitary hormone deficiency. J Clin Endocrinol Metab 2008; 93:4351-9. [PMID: 18728160 PMCID: PMC2582563 DOI: 10.1210/jc.2008-1189] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
CONTEXT Combined pituitary hormone deficiency (CPHD) is characterized by deficiencies in more than one anterior pituitary hormone. Mutations in developmental factors responsible for pituitary cell specification and gene expression have been found in CPHD patients. OTX2, a bicoid class homeodomain protein, is necessary for both forebrain development and transactivation of the HESX1 promoter, but as of yet, has not been associated with CPHD. OBJECTIVE The goal of this study was to identify and characterize novel mutations in pituitary specific transcription factors from CPHD patients. DESIGN Genomic DNA was isolated from patients with hypopituitarism to amplify and sequence eight pituitary specific transcription factors (HESX1, LHX3, LHX4, OTX2, PITX2, POU1F1, PROP1, and SIX6). Characterization of novel mutations is based on structural and functional studies. RESULTS We describe two unrelated children with CPHD who presented with neonatal hypoglycemia, and deficiencies of GH, TSH, LH, FSH, and ACTH. Magnetic resonance imaging revealed anterior pituitary hypoplasia with an ectopic posterior pituitary. A novel heterozygous OTX2 mutation (N233S) was identified. Wild-type and mutant OTX2 proteins bind equivalently to bicoid binding sites, whereas mutant OTX2 revealed decreased transactivation. CONCLUSIONS A novel mutation in OTX2 binds normally to target genes and acts as a dominant negative inhibitor of HESX1 gene expression. This suggests that the expression of HESX1, required for spaciotemporal development of anterior pituitary cell types, when disrupted, results in an absent or underdeveloped anterior pituitary with diminished hormonal expression. These results demonstrate a novel mechanism for CPHD and extend our knowledge of the spectrum of gene mutations causing CPHD.
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Muñoz Maniega S, Cvoro V, Armitage PA, Marshall I, Bastin ME, Wardlaw JM. Choline and creatine are not reliable denominators for calculating metabolite ratios in acute ischemic stroke. Stroke 2008; 39:2467-9. [PMID: 18617668 DOI: 10.1161/strokeaha.107.507020] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Choline and creatine are commonly used as denominators for other metabolites in ischemic stroke spectroscopy, assuming that they do not change. We investigated their concentration variation over time after stroke. METHODS Choline and creatine concentrations were measured by proton MR spectroscopic imaging in 51 patients at 5 times up to 3 months after stroke. RESULTS Choline and creatine levels changed significantly in the ischemic region. Choline was significantly reduced during the first 2 weeks after stroke onset (P=0.034). Creatine was significantly reduced during the whole period of the study (P=0.011). CONCLUSIONS Choline and creatine concentrations are not reliable denominators for metabolite ratios in acute stroke because their levels vary significantly in ischemic brain regions.
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Harris B, Andrews P, Marshall I, Robinson T, Murray G. Forced convective head cooling device reduces human cross-sectional brain temperature measured by magnetic resonance: a non-randomized healthy volunteer pilot study. Br J Anaesth 2008; 100:365-72. [DOI: 10.1093/bja/aem405] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Abstract
BACKGROUND Of the eight trials conducted since 1984 investigating the use of zinc in the treatment of the common cold, four have shown some benefit while the remainder have shown no benefit. Treatment masking and reduced bioavailability of zinc from some formulations have been claimed to influence the results reported. This review was undertaken to assess the overall usefulness of zinc as a treatment for the common cold. OBJECTIVES Interest in zinc as a treatment for the common cold has grown following the recent publication of several controlled trials. The objective of this review was to assess the effects of zinc lozenges for cold symptoms. SEARCH STRATEGY A search was made of the Cochrane Controlled Trials Register, MEDLINE, EMBASE and reference lists of articles. Searches were run to the end of 1997. SELECTION CRITERIA Randomised double blind placebo-controlled trials of zinc for acute upper respiratory tract infection or cold. DATA COLLECTION AND ANALYSIS Two reviewers independently extracted data and assessed trial quality. MAIN RESULTS Seven trials involving 754 cases were included. With the exception of one study, the methodological quality was rated as medium to high. For most outcome measures different summary estimates were used across the studies to describe the duration, incidence and severity of respiratory symptoms. This limited the ability to pool results. Results from two trials (04 - Mossad; 08 - Smith) suggested zinc lozenges reduced the severity and duration of cold symptoms. However, there was significant potential for bias, and further research is required to substantiate these findings. Overall, the results suggest that treatment with zinc lozenges did not reduce the duration of cold symptoms. AUTHORS' CONCLUSIONS Evidence of the effects of zinc lozenges for treating the common cold is inconclusive. Given the potential for treatment to produce side effects, the use of zinc lozenges to treat cold symptoms deserves further study.[This abstract has been prepared centrally.].
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Lymer K, Haga K, Marshall I, Sailasuta N, Wardlaw J. Reproducibility of GABA measurements using 2D J-resolved magnetic resonance spectroscopy. Magn Reson Imaging 2007; 25:634-40. [PMID: 17540274 DOI: 10.1016/j.mri.2006.10.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 10/01/2006] [Indexed: 10/23/2022]
Abstract
We determined the reproducibility of GABA (gamma-aminobutyric acid) measurements using 2D J-resolved magnetic resonance spectroscopy (MRS) on a clinical 1.5-T MR imaging scanner. Two-dimensional J-resolved spectra were acquired in vitro across five GABA concentrations using a volume head coil and a 5-in. surface coil. Additional spectra using a sixth GABA phantom with a very low concentration and from a healthy volunteer were recorded in the 5-in. surface coil only. In each case, the 3.01-ppm GABA resonance was quantified; for comparison, the peak integrals of choline (3.2 ppm) and creatine (3.03 ppm) were recorded. At a physiological concentration (1.2 mM), in vitro GABA measurement was significantly more reproducible in the surface coil than in the volume coil (P=.005), with coefficients of variation (CVs) being less than 16% with the surface coil and up to 68% with the volume head coil. At the smallest concentration of in vivo GABA reported using other spectroscopy techniques (0.8 mM) and detected only using the surface coil, the CV for GABA was 23% and was less than 10% for choline and creatine, which compare favorably with results from published studies. In vivo, the CV for GABA measurement was 26%, suggesting that 2D J-resolved MRS would be suitable for detecting physiological changes in GABA, similar to those reported using other methods.
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99
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Watts DM, Sutcliffe CJ, Morgan RH, Meagher S, Wardlaw J, Connell M, Bastin ME, Marshall I, Ramnarine KV, Hoskins PR, Black RA. Anatomical flow phantoms of the nonplanar carotid bifurcation, part I: computer-aided design and fabrication. ULTRASOUND IN MEDICINE & BIOLOGY 2007; 33:296-302. [PMID: 17306699 DOI: 10.1016/j.ultrasmedbio.2006.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Revised: 07/28/2006] [Accepted: 08/10/2006] [Indexed: 05/14/2023]
Abstract
Doppler ultrasound is widely used in the diagnosis and monitoring of arterial disease. Current clinical measurement systems make use of continuous and pulsed ultrasound to measure blood flow velocity; however, the uncertainty associated with these measurements is great, which has serious implications for the screening of patients for treatment. Because local blood flow dynamics depend to a great extent on the geometry of the affected vessels, there is a need to develop anatomically accurate arterial flow phantoms with which to assess the accuracy of Doppler blood flow measurements made in diseased vessels. In this paper, we describe the computer-aided design and manufacturing (CAD-CAM) techniques that we used to fabricate anatomical flow phantoms based on images acquired by time-of-flight magnetic resonance imaging (TOF-MRI). Three-dimensional CAD models of the carotid bifurcation were generated from data acquired from sequential MRI slice scans, from which solid master patterns were made by means of stereolithography. Thereafter, an investment casting procedure was used to fabricate identical flow phantoms for use in parallel experiments involving both laser and Doppler ultrasound measurement techniques.
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Harris B, Andrews P, Marshall I, Robinson T, Murray G. Reduction of magnetic resonance spectroscopy brain temperature by convective head cooling in healthy humans. Crit Care 2007. [PMCID: PMC4095384 DOI: 10.1186/cc5491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
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