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Coull G, Morris PG. The clinical effectiveness of CBT-based guided self-help interventions for anxiety and depressive disorders: a systematic review. Psychol Med 2011; 41:2239-2252. [PMID: 21672297 DOI: 10.1017/s0033291711000900] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Cognitive-behavioural therapy (CBT)-based guided self-help (GSH) has been suggested to be an effective intervention for mild to moderate anxiety and depression, yet the evidence seems inconclusive, with some studies reporting that GSH is effective and others finding that GSH is ineffective. GSH differs in important respects from other levels of self-help, yet the literature regarding exclusively guided self-help interventions for anxiety and depression has not been reviewed systematically. METHOD A literature search for randomized controlled trials (RCTs) examining CBT-based GSH interventions for anxiety and depressive disorders was conducted. Multiple electronic databases were searched; several journals spanning key disciplines were hand-searched; reference lists of included review articles were scanned and relevant first authors were contacted. RESULTS Thirteen studies met the inclusion criteria. Meta-analysis indicated the effectiveness of GSH at post-treatment, although GSH was found to have limited effectiveness at follow-up or among more clinically representative samples. Studies that reported greater effectiveness of GSH tended to be of lower methodological quality and generally involved participants who were self-selected rather than recruited through clinical referrals. CONCLUSIONS Although there is support for the effectiveness of CBT-based GSH among media-recruited individuals, the finding that the reviewed RCTs had limited effectiveness within routine clinical practice demonstrates that the evidence is not conclusive. Further rigorous evidence based on clinical populations that examines longer-term outcomes is required before CBT-based GSH interventions can be deemed effective for adults accessing primary care services for treatment of anxiety and depression.
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Hall EL, Driver ID, Croal PL, Francis ST, Gowland PA, Morris PG, Brookes MJ. The effect of hypercapnia on resting and stimulus induced MEG signals. Neuroimage 2011; 58:1034-43. [DOI: 10.1016/j.neuroimage.2011.06.073] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 06/01/2011] [Accepted: 06/24/2011] [Indexed: 10/18/2022] Open
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Stephenson MC, Gunner F, Napolitano A, Greenhaff PL, MacDonald IA, Saeed N, Vennart W, Francis ST, Morris PG. Applications of multi-nuclear magnetic resonance spectroscopy at 7T. World J Radiol 2011; 3:105-13. [PMID: 21532871 PMCID: PMC3084434 DOI: 10.4329/wjr.v3.i4.105] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 04/02/2011] [Accepted: 04/09/2011] [Indexed: 02/06/2023] Open
Abstract
AIM: To discuss the advantages of ultra-high field (7T) for 1H and 13C magnetic resonance spectroscopy (MRS) studies of metabolism.
METHODS: Measurements of brain metabolites were made at both 3 and 7T using 1H MRS. Measurements of glycogen and lipids in muscle were measured using 13C and 1H MRS respectively.
RESULTS: In the brain, increased signal-to-noise ratio (SNR) and dispersion allows spectral separation of the amino-acids glutamate, glutamine and γ-aminobutyric acid (GABA), without the need for sophisticated editing sequences. Improved quantification of these metabolites is demonstrated at 7T relative to 3T. SNR was 36% higher, and measurement repeatability (% coefficients of variation) was 4%, 10% and 10% at 7T, vs 8%, 29% and 21% at 3T for glutamate, glutamine and GABA respectively. Measurements at 7T were used to compare metabolite levels in the anterior cingulate cortex (ACC) and insula. Creatine and glutamate levels were found to be significantly higher in the insula compared to the ACC (P < 0.05). In muscle, the increased SNR and spectral resolution at 7T enables interleaved studies of glycogen (13C) and intra-myocellular lipid (IMCL) and extra-myocellular lipid (EMCL) (1H) following exercise and re-feeding. Glycogen levels were significantly decreased following exercise (-28% at 50% VO2 max; -58% at 75% VO2 max). Interestingly, levels of glycogen in the hamstrings followed those in the quadriceps, despite reduce exercise loading. No changes in IMCL and EMCL were found in the study.
CONCLUSION: The demonstrated improvements in brain and muscle MRS measurements at 7T will increase the potential for use in investigating human metabolism and changes due to pathologies.
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Stevenson CM, Brookes MJ, Morris PG. β-Band correlates of the fMRI BOLD response. Hum Brain Mapp 2011; 32:182-97. [PMID: 21229612 DOI: 10.1002/hbm.21016] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Oscillatory activity in the β-band (15-30 Hz) has been studied in detail in the sensorimotor cortex. It has been postulated that β-activity acts as a localized gating of cortical activity. Here, the induced oscillatory response in the β-band is measured by magnetoencephalography, and the hemodynamic response is measured by fMRI. We assess the linearity of the responses to stimuli of varying duration in the primary motor cortex and to a sinusoidal drifting grating of varying contrast amplitude and drift frequency in the visual cortex. In this way, we explore the nature of β-oscillations and their relationship with hemodynamic effects. Excellent spatial colocalization of BOLD and β-activity in both central and lateral (MT) visual areas and sensorimotor areas suggests that the two are intimately related. In contrast to the BOLD response, the level of β-desynchronization is not modulated by stimulus contrast or by stimulus duration, consistent with a gating role. The amplitude of β-desynchronization in the central visual area is however modulated by drift frequency, and this seems to parallel the modulation in BOLD amplitude at the same location.
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Tallantyre EC, Dixon JE, Donaldson I, Owens T, Morgan PS, Morris PG, Evangelou N. Ultra-high-field imaging distinguishes MS lesions from asymptomatic white matter lesions. Neurology 2011; 76:534-9. [PMID: 21300968 DOI: 10.1212/wnl.0b013e31820b7630] [Citation(s) in RCA: 152] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES To investigate whether multiple sclerosis (MS) and non-MS white matter brain lesions can be distinguished by their appearance on 7 T T2*-weighted MRI. METHODS This was an observational study of 28 patients with MS and 17 patients with cerebral white matter lesions who did not have MS. Subjects were imaged using 7 T T2*-weighted imaging. White matter lesions were identified and analyzed for volume, location, and perivenous appearance. RESULTS Out of 901 lesions identified in patients with MS, 80% were perivenous. In comparison, 19% of 428 lesions identified in patients without MS had a perivenous appearance. Seven-Tesla T2*-weighted MRI reliably distinguished all patients with clinically definite MS (>40% lesions appeared perivenous) from those without clinical MS (<40% lesions appeared perivenous). Perivenous lesion appearance was more predictive of MS (odds ratio [OR] 14, p < 0.001) than subcortical or periventricular lesion location (OR 4.5, p < 0.001, and OR 2.4, p = 0.009). Perivenous lesion appearance was observed with a similar frequency in patients with clinically isolated syndrome of demyelination and in early (gadolinium-enhancing) MS lesions. CONCLUSION Perivenous lesion location on 7 T T2*-weighted imaging is predictive of the presence of demyelination. Optimization of this imaging technique at lower magnetic resonance field strengths would offer benefit for the diagnosis of MS.
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Fornier MN, Morris PG, Abbruzzi A, D'Andrea G, Gilewski T, Bromberg J, Dang C, Dickler M, Modi S, Seidman AD, Sklarin N, Chang J, Norton L, Hudis CA. A phase I study of dasatinib and weekly paclitaxel for metastatic breast cancer. Ann Oncol 2011; 22:2575-2581. [PMID: 21406471 DOI: 10.1093/annonc/mdr018] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND SRC plays an important role in the pathogenesis of metastatic breast cancer (MBC). In preclinical models, paclitaxel and the oral SRC inhibitor dasatinib showed greater antitumor activity than either agent. To determine the maximum tolerated dose of this combination, we conducted a phase I study. PATIENTS AND METHODS Patients with MBC; Eastern Cooperative Oncology Group performance status of zero to one; normal hepatic, renal and marrow function were eligible. Paclitaxel 80 mg/m(2) was given 3 weeks of 4. The starting dasatinib dose was 70 mg and was increased, using a standard 3 + 3 dose-escalation scheme. RESULTS Fifteen patients enrolled (median age 54 years, range 35-74). No dose-limiting toxic effects (DLTs) occurred at dasatinib doses of 70-120 mg. One DLT (grade 3 fatigue) occurred in the dasatinib 150-mg cohort, which was expanded (six patients) with no further DLTs. However, due to cumulative toxic effects (rash, fatigue, diarrhea), the recommended phase II dose is dasatinib 120 mg. Of 13 assessable patients, a partial response was seen in 4 patients (31%), including 2 patients previously treated with taxanes; all received ≥120 mg dasatinib. An additional five patients (29%) had stable disease. CONCLUSION In combination with weekly paclitaxel, the recommended phase II dose of dasatinib is 120 mg daily and preliminary activity has been seen in patients with MBC.
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Brookes MJ, Hale JR, Zumer JM, Stevenson CM, Francis ST, Barnes GR, Owen JP, Morris PG, Nagarajan SS. Measuring functional connectivity using MEG: methodology and comparison with fcMRI. Neuroimage 2011; 56:1082-104. [PMID: 21352925 PMCID: PMC3224862 DOI: 10.1016/j.neuroimage.2011.02.054] [Citation(s) in RCA: 319] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 01/21/2011] [Accepted: 02/17/2011] [Indexed: 01/08/2023] Open
Abstract
Functional connectivity (FC) between brain regions is thought to be central to the way in which the brain processes information. Abnormal connectivity is thought to be implicated in a number of diseases. The ability to study FC is therefore a key goal for neuroimaging. Functional connectivity (fc) MRI has become a popular tool to make connectivity measurements but the technique is limited by its indirect nature. A multimodal approach is therefore an attractive means to investigate the electrodynamic mechanisms underlying hemodynamic connectivity. In this paper, we investigate resting state FC using fcMRI and magnetoencephalography (MEG). In fcMRI, we exploit the advantages afforded by ultra high magnetic field. In MEG we apply envelope correlation and coherence techniques to source space projected MEG signals. We show that beamforming provides an excellent means to measure FC in source space using MEG data. However, care must be taken when interpreting these measurements since cross talk between voxels in source space can potentially lead to spurious connectivity and this must be taken into account in all studies of this type. We show good spatial agreement between FC measured independently using MEG and fcMRI; FC between sensorimotor cortices was observed using both modalities, with the best spatial agreement when MEG data are filtered into the β band. This finding helps to reduce the potential confounds associated with each modality alone: while it helps reduce the uncertainties in spatial patterns generated by MEG (brought about by the ill posed inverse problem), addition of electrodynamic metric confirms the neural basis of fcMRI measurements. Finally, we show that multiple MEG based FC metrics allow the potential to move beyond what is possible using fcMRI, and investigate the nature of electrodynamic connectivity. Our results extend those from previous studies and add weight to the argument that neural oscillations are intimately related to functional connectivity and the BOLD response.
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Tallantyre EC, Morgan PS, Dixon JE, Al-Radaideh A, Brookes MJ, Morris PG, Evangelou N. 3 Tesla and 7 Tesla MRI of multiple sclerosis cortical lesions. J Magn Reson Imaging 2011; 32:971-7. [PMID: 20882628 DOI: 10.1002/jmri.22115] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cortical lesions are prevalent in multiple sclerosis but are poorly detected using MRI. The double inversion recovery (DIR) sequence is increasingly used to explore the clinical relevance of cortical demyelination. Here we evaluate the agreement between imaging sequences at 3 Tesla (T) and 7T for the presence and appearance of individual multiple sclerosis cortical lesions. Eleven patients with demyelinating disease and eight healthy volunteers underwent MR imaging at 3T (fluid attenuated inversion recovery [FLAIR], DIR, and T(1)-weighted magnetization prepared rapid acquisition gradient echo [MP-RAGE] sequences) and 7T (T(1)-weighted MP-RAGE). There was good agreement between images for the presence of mixed cortical lesions (involving both gray and white matter). However, agreement between imaging sequences was less good for purely intracortical lesions. Even after retrospective analysis, 25% of cortical lesions could only be visualized on a single MRI sequence. Several DIR hyperintensities thought to represent cortical lesions were found to correspond to signal arising from extracortical blood vessels. High-resolution 7T imaging appeared useful for confidently classifying the location of lesions in relation to the cortical/subcortical boundary. We conclude that DIR, FLAIR, and MP-RAGE imaging sequences appear to provide complementary information during the detection of multiple sclerosis cortical lesions. High resolution 7T imaging may facilitate anatomical localization of lesions in relation to the cortical boundary.
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Morris PG, Abbruzzi A, D'Andrea G, Gilewski T, Lake D, Bromberg J, Dang C, Dickler M, Modi S, Seidman AD, Sklarin N, Chang J, Patil S, Norton L, Hudis CA, Fornier MN. Abstract P6-12-09: A Phase I-II Trial of Dasatinib (D) in Combination with Weekly (w) Paclitaxel (P) for Patients (Pts) with Metastatic Breast Carcinoma (MBC). Cancer Res 2010. [DOI: 10.1158/0008-5472.sabcs10-p6-12-09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Inhibition of SRC is a novel approach for MBC. D is an inhibitor of multiple tyrosine kinases, including the SRC family. Pre-clinical data show D inhibits multiple breast cancer cell lines, including those of “basal-like” subtype. In preclinical models D + P had superior antitumor activity to either agent alone. We designed this phase I-II study to translate this observation.
Methods: For phase I: pts with MBC, ECOG PS 0-1, normal hepatic, renal, marrow function were eligible. Pts with pleural/pericardial effusions were excluded. For phase II: pts had measurable, HER2-negative MBC, ≥2 prior rx for MBC. Prior taxanes, stable brain metastases and baseline neuropathy grade ≥1 were allowed. Cycle (C) consisted of wP 80 mg/m2 IV 3/4 weeks + D 70mg orally daily; escalating to 100 mg, 120 mg and 150 mg in cohorts of 3pts. Toxicity was assessed by CTCAE v3.0, response by RECIST.
Results: 17 pts enrolled (15 phase I; 2 phase II); median age 54 (range 35-74), median PS=1 (range 0-1). 12 (71%) pts rcvd prior adjuvant chemoRx. Pts rcvd a median of 3 prior rx for MBC (range 0-12). Pts rcvd median of 2 C of D + P (range 1-14). One DLT occurred at 150mg (G3 fatigue); this cohort was expanded with no further DLTs. However 3 pts on this dose level withdrew;1 pt delayed hypersensitivity rash (grade 1), 1 pt febrile neutropenia (grade 3), 1 pt paclitaxel pneumonitis (grade 3). Therefore the phase II dose is D 120mg. Overall the most common toxicities have been hematologic and low G (table). 13 pts are assessable for response; 4 patients (31%) had a PR, including 3 patients previously treated with taxanes. 5 pts (29%) had stable disease.
Toxicities > Grade 1
Conclusion: Treatment with wP and D is feasible in pts with MBC. In the phase I study, 1 DLT occurred at D 150mg but due to cumulative toxicities the recommended dose for the ongoing phase II study is 120mg. Preliminary evidence of activity has been seen in taxane-pretreated pts at the phase II dose. Identification of biomarkers to select appropriate pts for this therapeutic approach is the subject of ongoing correlative studies.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-12-09.
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Brookes MJ, Wood JR, Stevenson CM, Zumer JM, White TP, Liddle PF, Morris PG. Changes in brain network activity during working memory tasks: a magnetoencephalography study. Neuroimage 2010; 55:1804-15. [PMID: 21044687 DOI: 10.1016/j.neuroimage.2010.10.074] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 10/16/2010] [Accepted: 10/26/2010] [Indexed: 11/16/2022] Open
Abstract
In this study, we elucidate the changes in neural oscillatory processes that are induced by simple working memory tasks. A group of eight subjects took part in modified versions of the N-back and Sternberg working memory paradigms. Magnetoencephalography (MEG) data were recorded, and subsequently processed using beamformer based source imaging methodology. Our study shows statistically significant increases in θ oscillations during both N-back and Sternberg tasks. These oscillations were shown to originate in the medial frontal cortex, and further to scale with memory load. We have also shown that increases in θ oscillations are accompanied by decreases in β and γ band oscillations at the same spatial coordinate. These decreases were most prominent in the 20-40 Hz frequency range, although spectral analysis showed that γ band power decrease extends up to at least 80 Hz. β/γ Power decrease also scales with memory load. Whilst θ increases were predominately observed in the medial frontal cortex, β/γ decreases were associated with other brain areas, including nodes of the default mode network (for the N-back task) and areas associated with language processing (for the Sternberg task). These observations are in agreement with intracranial EEG and fMRI studies. Finally, we have shown an intimate relationship between changes in β/γ band oscillatory power at spatially separate network nodes, implying that activity in these nodes is not reflective of uni-modal task driven changes in spatially separate brain regions, but rather represents correlated network activity. The utility of MEG as a non-invasive means to measure neural oscillatory modulation has been demonstrated and future studies employing this technology have the potential to gain a better understanding of neural oscillatory processes, their relationship to functional and effective connectivity, and their correspondence to BOLD fMRI.
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Hale JR, Brookes MJ, Hall EL, Zumer JM, Stevenson CM, Francis ST, Morris PG. Comparison of functional connectivity in default mode and sensorimotor networks at 3 and 7T. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2010; 23:339-49. [PMID: 20625794 DOI: 10.1007/s10334-010-0220-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 05/28/2010] [Accepted: 06/18/2010] [Indexed: 11/26/2022]
Abstract
OBJECT The objective of this work was to assess functional connectivity measurements at ultra-high field (7T), given BOLD contrast to noise ratio increases with magnetic field strength but physiological noise also increases. MATERIALS AND METHODS Resting state BOLD data were acquired at 3 and 7T to assess connectivity in the sensorimotor network (SMN) and default mode network (DMN) at different spatial smoothing levels. RESULTS At 3 and 7T positive correlation is observed between a right sensorimotor seed and left sensorimotor cortex. For the DMN, a seed in posterior cingulate cortex results in a high correlation in inferior parietal lobes and medial prefrontal cortex. We show higher temporal correlation coefficients for both the SMN and DMN at 7T compared to 3T for all smoothing levels. A spatial correlation between connectivity maps revealed no significant differences for the SMN, whilst the DMN showed increased spatial correlation dependent on SNR. The maximum physiological noise contribution was found to be higher at 7T, but noise in both seed and network nodes was not significantly increased, as shown by no significant difference in the spatial correlation of maps following physiological correction. CONCLUSION 7T can improve spatial specificity of connectivity maps and facilitate measurement of connectivity in areas of lower intrinsic network correlation.
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Brookes MJ, Zumer JM, Stevenson CM, Hale JR, Barnes GR, Vrba J, Morris PG. Investigating spatial specificity and data averaging in MEG. Neuroimage 2009; 49:525-38. [PMID: 19635575 PMCID: PMC3224863 DOI: 10.1016/j.neuroimage.2009.07.043] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2009] [Revised: 07/09/2009] [Accepted: 07/13/2009] [Indexed: 11/25/2022] Open
Abstract
This study shows that the spatial specificity of MEG beamformer estimates of electrical activity can be affected significantly by the way in which covariance estimates are calculated. We define spatial specificity as the ability to extract independent timecourse estimates of electrical brain activity from two separate brain locations in close proximity. Previous analytical and simulated results have shown that beamformer estimates are affected by narrowing the time frequency window in which covariance estimates are made. Here we build on this by both experimental validation of previous results, and investigating the effect of data averaging prior to covariance estimation. In appropriate circumstances, we show that averaging has a marked effect on spatial specificity. However the averaging process results in ill-conditioned covariance matrices, thus necessitating a suitable matrix regularisation strategy, an example of which is described. We apply our findings to an MEG retinotopic mapping paradigm. A moving visual stimulus is used to elicit brain activation at different retinotopic locations in the visual cortex. This gives the impression of a moving electrical dipolar source in the brain. We show that if appropriate beamformer optimisation is applied, the moving source can be tracked in the cortex. In addition to spatial reconstruction of the moving source, we show that timecourse estimates can be extracted from neighbouring locations of interest in the visual cortex. If appropriate methodology is employed, the sequential activation of separate retinotopic locations can be observed. The retinotopic paradigm represents an ideal platform to test the spatial specificity of source localisation strategies. We suggest that future comparisons of MEG source localisation techniques (e.g. beamformer, minimum norm, Bayesian) could be made using this retinotopic mapping paradigm.
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Zumer JM, Stevenson CM, Brookes MJ, Francis ST, Morris PG. Deconvolved fMRI correlates with source-localised MEG as a function of neural frequency oscillation. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)71719-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Brookes MJ, Stevenson CM, Zumer JM, Morris PG. Imaging non-stationary brain sources using MEG. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70594-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Morris PG, O'Connor M, O'Rafferty C, Sheikh R, Gray J, McDermott R, Boyle T, Kennedy MJ. The excessive cost of baseline diagnostic imaging in early breast cancer. IRISH MEDICAL JOURNAL 2009; 102:149-152. [PMID: 19623811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Many patients with newly diagnosed breast cancer undergo multiple staging investigations. We aimed to assess the use and yield of baseline diagnostic imaging in early-stage breast cancer. A review of all patients diagnosed with breast cancer over five years at a single institution was carried out. 781 patients were included. At diagnosis 266 (34%) patients underwent a bone scan, which showed metastases in 42 (15.8%), of whom 26 (61.9%) were symptomatic with pain. Only two asymptomatic patients had incidental skeletal metastases detected at an estimated cost of euro 50,850 per case. 261 (33.4%) patients underwent hepatic ultrasonography, which showed metastases in 23 (8.8%), of whom 19 (82.6%) had abnormal liver blood tests. Only two patients had incidental hepatic metastases detected at an estimated cost of euro 29,400 per case. The routine use of these imaging modalities to detect metastases in asymptomatic early-stage breast cancer patients is not justified.
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Brookes MJ, Vrba J, Mullinger KJ, Geirsdóttir GB, Yan WX, Stevenson CM, Bowtell R, Morris PG. Source localisation in concurrent EEG/fMRI: Applications at 7T. Neuroimage 2009; 45:440-52. [DOI: 10.1016/j.neuroimage.2008.10.047] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 10/14/2008] [Accepted: 10/24/2008] [Indexed: 10/21/2022] Open
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Jones KL, Finn DP, Governo RJM, Prior MJ, Morris PG, Kendall DA, Marsden CA, Chapman V. Identification of discrete sites of action of chronic treatment with desipramine in a model of neuropathic pain. Neuropharmacology 2008; 56:405-13. [PMID: 18930746 DOI: 10.1016/j.neuropharm.2008.09.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2008] [Revised: 09/11/2008] [Accepted: 09/12/2008] [Indexed: 12/19/2022]
Abstract
Tricyclic antidepressants (TCAs) are an important analgesic treatment for neuropathic pain, though the neural substrates mediating these effects are poorly understood. We have used an integrative approach combining behavioural pharmacology with functional magnetic resonance imaging (fMRI) to investigate the effects of chronic treatment with the TCA desipramine, on touch-evoked pain (mechanical allodynia) and brain regional activity in the selective spinal nerve ligation (SNL) model of neuropathic pain. SNL and sham-operated rats received once daily i.p. administration of 10 mg/kg DMI, or saline, for 14 days. Withdrawal responses to the application of a normally non-noxious (10 g) stimulus were recorded in SNL and sham-operated rats over this period. On the final day of the study, SNL and sham-operated rats received a final challenge dose of DMI (10 mg/kg i.p.) during fMRI scanning. Chronic administration of desipramine (DMI) significantly attenuated mechancial allodynia in SNL rats. DMI challenge in chronic DMI-treated neuropathic rats produced significantly greater activation of the deep mesencephalic nucleus, primary somatosensory cortex, insular cortex, medial globus pallidus, inferior colliculus, perirhinal cortex and cerebellum compared to sham-operated rats and saline controls. By contrast, the spatial pattern of brain regional activation by chronic DMI treatment in sham controls encompassed a number of other areas including those associated with learning and memory processes. These novel findings identify key brain regions implicated in the analgesic and mood altering effects associated with chronic treatment with DMI.
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Tallantyre EC, Brookes MJ, Dixon JE, Morgan PS, Evangelou N, Morris PG. Demonstrating the perivascular distribution of MS lesions in vivo with 7-Tesla MRI. Neurology 2008; 70:2076-8. [PMID: 18505982 DOI: 10.1212/01.wnl.0000313377.49555.2e] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Brookes MJ, Vrba J, Robinson SE, Stevenson CM, Peters AM, Barnes GR, Hillebrand A, Morris PG. Optimising experimental design for MEG beamformer imaging. Neuroimage 2007; 39:1788-802. [PMID: 18155612 DOI: 10.1016/j.neuroimage.2007.09.050] [Citation(s) in RCA: 195] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Revised: 09/19/2007] [Accepted: 09/22/2007] [Indexed: 11/17/2022] Open
Abstract
In recent years, the use of beamformers for source localisation has significantly improved the spatial accuracy of magnetoencephalography. In this paper, we examine techniques by which to optimise experimental design, and ensure that the application of beamformers yields accurate results. We show that variation in the experimental duration, or variation in the bandwidth of a signal of interest, can significantly affect the accuracy of a beamformer reconstruction of source power. Specifically, power will usually be underestimated if covariance windows are made too short, or bandwidths too narrow. The accuracy of spatial localisation may also be reduced. We conclude that for optimum accuracy, experimenters should aim to collect as much data as possible, and use a bandwidth spanning the entire frequency distribution of the signal of interest. This minimises distortion to reconstructed source images, time courses and power estimation. In the case where experimental duration is short, and small covariance windows are therefore used, we show that accurate power estimation can be achieved by matrix regularisation. However, large amounts of regularisation cause a loss in the spatial resolution of the MEG beamformer, hence regularisation should be used carefully, particularly if multiple sources in close proximity are expected.
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Brookes MJ, Morris PG, Gowland PA, Francis ST. Noninvasive measurement of arterial cerebral blood volume using Look-Locker EPI and arterial spin labeling. Magn Reson Med 2007; 58:41-54. [PMID: 17659615 DOI: 10.1002/mrm.21199] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This paper describes a method of noninvasively measuring regional arterial cerebral blood volume fractions (CBV(a)) in vivo using the combination of Look-Locker echo-planar imaging (LL-EPI) with arterial spin labeling (ASL). Using this technique the arterial inflow curve is rapidly sampled and the regional CBV(a) is measured, while tissue perfusion signals are suppressed. Two methods of spin labeling (LL-EPI flow-sensitive alternating inversion recovery (LL-EPI-FAIR) and LL-EPI signal targeting using alternating radiofrequency (LL-EPI-STAR)) are assessed and their advantages discussed. The application of vascular crushing to LL-EPI-FAIR is described and used to validate the insensitivity of the sequence to the perfusion difference signal. LL-EPI-STAR is used to assess changes in CBV(a) in response to a finger-tapping task. LL-EPI-STAR signal difference curves are shown to have a shortened vascular transit delay and increased peak signal change on activation. A 33 +/- 14% increase in CBV(a) on activation is found. CBV(a) is measured with a 6-s temporal resolution and the temporal response is compared with the BOLD signal change. CBV(a) is shown to increase more rapidly and return to baseline significantly faster than the BOLD signal change, which supports the suggestion that a change in CBV(a) is an input to the BOLD response.
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Morris PG, Davenport C, O'dwyer D, O'callaghan C, Breathnach OS, Grogan L. Practical problems and resource implications with the use of warfarin for venous thromboembolism in patients with cancer. Ir J Med Sci 2007; 176:165-8. [PMID: 17638061 DOI: 10.1007/s11845-007-0064-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2006] [Accepted: 06/22/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND Oral anticoagulants present multiple practical problems for patients undergoing chemotherapy. To assess the practice implications of anticoagulation therapy, a review was carried out. METHODS A review of all patients with cancer treated with warfarin for venous thromboembolism (VTE) over a 1-year-period was carried out. Adverse events and therapeutic efficacy were assessed and the extra volume of work involved in monitoring was quantified. RESULTS Fifty-five patients with cancer and VTE were treated with warfarin from 07/04 to 06/05. Twenty-one invasive interventions required disruption of anticoagulation. There were eight admissions for haemorrhage. Nine patients died while on warfarin. A total of 1,379 coagulation tests were performed. There were 382 extra dayward visits attributable to warfarin monitoring. On treatment, 13 patients (24%) were changed from warfarin therapy to low molecular weight heparin (LMWH). CONCLUSIONS This study identifies and quantifies the extra resource utilization with warfarin therapy in patients undergoing chemotherapy.
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Morris PG, Kelly R, Horgan A, Nasim S, Kehily D, Grogan L, Breathnach OS. Patterns of participation of patients in cancer clinical trials in Ireland. Ir J Med Sci 2007; 176:153-6. [PMID: 17619093 DOI: 10.1007/s11845-007-0058-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Accepted: 06/07/2007] [Indexed: 10/23/2022]
Abstract
BACKGROUND In the United States the overall participation in cancer clinical trials (CCT) is less than 3% [Avis et al. in J Clin Oncol 24:1860-1867 (2006); Lara et al. in J Clin Oncol 19:1728-1733 (2001)]. In Europe there is little data on participation in such trials. AIM We aim to gather information on factors influencing CCT enrolment in Ireland. METHODS From November 2005 to 28 February 2006 all consecutive patients considered for systemic therapy were assessed for eligibility re participation in available CCTs. RESULTS A total of 290 patients were included. Overall 2.4% of patients were recruited to one of the available CCTs. The main reasons for failure of trial recruit were: no trial for cancer type (60%), no trial for stage (21%), ineligible by trial criteria (16.1%), patient declined (0.3%), and physician discretion (2.6%). Only one patient, who was otherwise eligible, declined entry into a clinical trial. CONCLUSIONS Irish patients with cancer are very willing to participate in CCTs. Current levels of recruitment compare favourably with international levels.
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Peters AM, Brookes MJ, Hoogenraad FG, Gowland PA, Francis ST, Morris PG, Bowtell R. T2* measurements in human brain at 1.5, 3 and 7 T. Magn Reson Imaging 2007; 25:748-53. [PMID: 17459640 DOI: 10.1016/j.mri.2007.02.014] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Indexed: 12/30/2022]
Abstract
Measurements have been carried out in six subjects at magnetic fields of 1.5, 3 and 7 T, with the aim of characterizing the variation of T2* with field strength in human brain. Accurate measurement of T2* in the presence of macroscopic magnetic field inhomogeneity is problematic due to signal decay resulting from through-slice dephasing. The approach employed here allowed the signal decay due to through-slice dephasing to be characterized and removed from data, thus facilitating an accurate measurement of T2* even at ultrahigh field. Using double inversion recovery turbo spin-echo images for tissue classification, an analysis of T2* relaxation times in cortical grey matter and white matter was carried out, along with an evaluation of the variation of T2* with field strength in the caudate nucleus and putamen. The results show an approximately linear increase in relaxation rate R2* with field strength for all tissues, leading to a greater range of relaxation times across tissue types at 7 T that can be exploited in high-resolution T2*-weighted imaging.
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Brookes MJ, Stevenson CM, Barnes GR, Hillebrand A, Simpson MIG, Francis ST, Morris PG. Beamformer reconstruction of correlated sources using a modified source model. Neuroimage 2007; 34:1454-65. [PMID: 17196835 DOI: 10.1016/j.neuroimage.2006.11.012] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Revised: 10/20/2006] [Accepted: 11/02/2006] [Indexed: 11/17/2022] Open
Abstract
This paper introduces a lead field formulation for use in beamformer analysis of MEG data. This 'dual source beamformer' is a technique to image two temporally correlated sources using beamformer methodology. We show that while the standard, single source beamformer suppresses the reconstructed power of two spatially separate but temporally correlated sources, the dual source beamformer allows for their accurate reconstruction. The technique is proven to be accurate using simulations. We also show that it can be used to image accurately the auditory steady state response, which is correlated between the left and right auditory cortices. We suggest that this technique represents a useful way of locating correlated sources, particularly if a seed location can be defined a priori for one of the two sources. Such a priori information could be based on previous studies using similar paradigms, or from other functional neuroimaging techniques.
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Francis ST, Head K, Morris PG, Macdonald IA. The Effect of Flavanol-rich Cocoa on the fMRI Response to a Cognitive Task in Healthy Young People. J Cardiovasc Pharmacol 2006; 47 Suppl 2:S215-20. [PMID: 16794461 DOI: 10.1097/00005344-200606001-00018] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Flavanols are the main flavonoids found in cocoa and chocolate, and can be especially abundant in certain cocoas. Research over the past decade has identified flavanols as showing diverse beneficial physiologic and antioxidant effects, particularly in context of vascular function. The present study employed functional magnetic resonance imaging based on blood oxygenation level-dependent (BOLD) contrast to explore the effect of flavanols on the human brain. Magnetic resonance imaging was used to measure BOLD responses to a cognitive task in 16 healthy young subjects. The data presented show an increase in the BOLD signal intensity in response to a cognitive task following ingestion of flavanol-rich cocoa (5 days of 150 mg of cocoa flavanols). This may arise either as a result of altered neuronal activity, or a change in vascular responsiveness, or both--the net effect then being dependent on which of the two effects is dominant. No significant effects were evident in behavioral reaction times, switch cost, and heart rate after consumption of this moderate dose of cocoa flavanols. A pilot study evaluated the relationship between cerebral blood flow and a single acute dose (450 mg flavanols) of flavanol-rich cocoa and showed that flavanol-rich cocoa can increase the cerebral blood flow to gray matter, suggesting the potential of cocoa flavanols for treatment of vascular impairment, including dementia and strokes, and thus for maintaining cardiovascular health.
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Jones NC, Prior MJW, Burden-Teh E, Marsden CA, Morris PG, Murphy S. Antagonism of the interleukin-1 receptor following traumatic brain injury in the mouse reduces the number of nitric oxide synthase-2-positive cells and improves anatomical and functional outcomes. Eur J Neurosci 2005; 22:72-8. [PMID: 16029197 DOI: 10.1111/j.1460-9568.2005.04221.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Interleukin (IL)-1beta plays an important role in the inflammatory response that results from traumatic brain injury and antagonism of the actions of this cytokine can affect outcome. We subjected male mice to aseptic cryogenic injury and assessed recovery through anatomical, histological and functional measures following treatment with recombinant mouse IL-1 receptor antagonist (IL-1ra). A single dose (1 microg, i.c.v.) at the time of injury reduced lesion volume 3 days later, as assessed by Nissl staining, and also the number (30%) of FluoroJade-positive degenerating neurones. Mice treated with IL-1ra performed better on the beam balance and in the grid test as compared with vehicle-treated animals. Furthermore, IL-1ra-treated animals showed fewer (40%) nitric oxide synthase-2-positive cells in and around the lesion. These data suggest that activation of the IL-1 receptor following trauma contributes to the pathology and that antagonism can reduce both anatomical and functional consequences of neuroinflammation.
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Gibson AM, Brookes MJ, Kim SS, Francis ST, Morris PG. A new quantitative analysis of significant timing differences between externally cued and self-initiated motor tasks in an fMRI study. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2005; 28:258-65. [PMID: 16360581 DOI: 10.1016/j.ssnmr.2005.10.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Indexed: 05/05/2023]
Abstract
It is generally accepted that the temporal resolution of blood oxygenation level dependent functional MRI is limited due to the inherent latency and longevity of the haemodynamic response. However, in this study we introduce a technique for measurement of timing differences from within the same brain region in two (or more) separate tasks that allows accurate determination of cortical timing differences 200 ms. Our technique, based on a novel use of linear regression analysis, is shown to yield accurate results both in simulated and experimental data. We show that cortical timing differences measured using fMRI are consistent with published electrophysiological results. Measurement of timing differences using this technique could prove a useful strategy for identifying neural network components in a wide range of cognitive paradigms.
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Hewitt KN, Shah YB, Prior MJW, Morris PG, Hollis CP, Fone KCF, Marsden CA. Behavioural and pharmacological magnetic resonance imaging assessment of the effects of methylphenidate in a potential new rat model of attention deficit hyperactivity disorder. Psychopharmacology (Berl) 2005; 180:716-23. [PMID: 15864553 DOI: 10.1007/s00213-005-2272-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Accepted: 03/11/2005] [Indexed: 02/02/2023]
Abstract
RATIONALE The psychomotor stimulant methylphenidate is used in the treatment of attention deficit hyperactivity disorder (ADHD). Whereas the mechanism is not fully understood it is suggested to involve restoration of impaired dopamine function found in ADHD. OBJECTIVES The aim of this study was to determine the effects of methylphenidate on brain region activation in vivo using pharmacological magnetic resonance imaging (phMRI) in a potential rat model of ADHD. METHODS Rats were treated bi-daily [from postnatal day (PND) 24] for 4 days with the dopamine re-uptake inhibitor GBR 12909 (30 mg/kg i.p) or vehicle (control). On PND 57 rats were administered methylphenidate (4 mg/kg i.p) and locomotor activity measured. In a separate group of animals, blood oxygen level dependent (BOLD) response was measured using phMRI to determine changes in brain region activation produced by methylphenidate (4 mg/kg i.p.) in GBR 12909-pretreated or control rats. RESULTS Methylphenidate produced a greater locomotor-stimulant response in controls compared with GBR 12909 rats. Pretreatment with GBR 12909 reduced the BOLD response produced by methylphenidate compared with that in control animals. The main effects of methylphenidate on the BOLD response were seen in the caudate, frontal cortex, hippocampus and hypothalamus. CONCLUSIONS Short-term treatment with GBR 12909 in young rats causes long-term changes in dopaminergic systems, altering the methylphenidate-induced behavioural response and brain region activation compared with that in vehicle-pretreated rats. The results further support the view that altered dopaminergic function may be an important factor in ADHD and the value of animal models with this functional neurochemical deficit.
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Steward CA, Marsden CA, Prior MJW, Morris PG, Shah YB. Methodological considerations in rat brain BOLD contrast pharmacological MRI. Psychopharmacology (Berl) 2005; 180:687-704. [PMID: 15778890 DOI: 10.1007/s00213-005-2213-7] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2004] [Accepted: 02/14/2005] [Indexed: 02/02/2023]
Abstract
RATIONALE AND OBJECTIVES Blood oxygen level dependent (BOLD) contrast pharmacological magnetic resonance imaging (phMRI) is an increasingly popular technique that allows the non-invasive investigation of spatial and temporal changes in rat brain function in response to pharmacological stimulation in vivo. Rat brain BOLD contrast phMRI is, at present, established in few neuropharmacological laboratories, and various issues associated with the technique require attention. The present review is primarily aimed at psychopharmacologists with no previous experience of phMRI, who are interested in the practical aspects that phMRI studies entail. RESULTS AND DISCUSSION Experimental and analytical considerations, including anaesthesia, physiological monitoring, drug dose and delivery, scanning protocols, statistical approaches and the interpretation of phMRI data, are discussed.
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Shah YB, Haynes L, Prior MJW, Marsden CA, Morris PG, Chapman V. Functional magnetic resonance imaging studies of opioid receptor-mediated modulation of noxious-evoked BOLD contrast in rats. Psychopharmacology (Berl) 2005; 180:761-73. [PMID: 15778889 DOI: 10.1007/s00213-005-2214-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Accepted: 02/11/2005] [Indexed: 01/29/2023]
Abstract
RATIONALE Functional magnetic resonance imaging (fMRI) in rats can non-invasively identify brain regions activated by physiological stimuli and the effects of pharmacological intervention on these responses. OBJECTIVES This study was conducted to investigate the effects of systemic administration of the mu-opioid receptor agonist morphine on whole brain functional signal intensity in anaesthetised rats; to investigate whether pre-treatment with the opioid receptor antagonist naloxone blocks the effects of morphine; to determine whether pre-treatment with morphine attenuates noxious-evoked changes in whole brain functional signal intensity. METHODS Continuous whole brain fMRI scanning was used to study brain signal intensity prior to, and following, systemic administration of morphine (5 mg/kg, n=7), systemic administration of naloxone (1 mg/kg) and morphine (n=8). Effects of pre-treatment with saline (n=5) or morphine (5 mg/kg, n=5) on formalin (5%, intraplantar)-evoked changes in signal intensity were determined. Data were processed using SMP99 with fixed-effects analysis (p<0.05). RESULTS Morphine produced significant positive bilateral increases in signal intensity in the cingulate cortex, amygdala, thalamus, hypothalamus and PAG (p<0.05), and these effects were blocked by naloxone. Intraplantar injection of formalin produced a significant positive increase in signal intensity in the cingulate cortex, somatosensory cortex, amygdala, thalamus, hypothalamus and PAG (p<0.05). Morphine attenuated formalin-evoked increases in signal intensity in the PAG, amygdala, hypothalamus and cingulate cortex. CONCLUSION Our data demonstrate that morphine modulates noxious-evoked changes in signal intensity in discrete brain regions. fMRI studies in rats are able to identify specific brain regions involved in the pharmacological modification of physiologically evoked changes in regional brain activation.
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Jones NC, Constantin D, Prior MJW, Morris PG, Marsden CA, Murphy S. The neuroprotective effect of progesterone after traumatic brain injury in male mice is independent of both the inflammatory response and growth factor expression. Eur J Neurosci 2005; 21:1547-54. [PMID: 15845082 DOI: 10.1111/j.1460-9568.2005.03995.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Previous studies suggest that progesterone may possess neuroprotective properties after traumatic insult but, with the exception of reduced formation of cerebral oedema, limited experimental evidence has been presented to support this claim. In the present study we focused on the effect of progesterone treatment on structural and functional deficits in an experimental model of traumatic brain injury. Female mice exhibited significantly (P = 0.0445) reduced lesion volumes compared with males after aseptic cryogenic cerebral injury (ACI), suggesting that female sex steroids provide protection against this injury. In male mice, progesterone treatment after injury (three intraperitoneal doses of 8 mg/kg) reduced lesion volume (P = 0.0429) and improved performance in a spatial cognitive task (Morris water maze; P = 0.0014). However, progesterone had no demonstrable effect on the formation of oedema as measured using T2-weighted magnetic resonance imaging, nor did it affect brain water content. The pro-inflammatory cytokines TNF-alpha and IL-1beta, and growth factors BDNF and G-CSF, were all strongly transcriptionally activated after ACI. However, progesterone administration did not affect expression of these genes. This study provides strong evidence that progesterone possesses neuroprotective properties in a mouse model of traumatic brain injury, but suggests that the steroid achieves this effect through mechanism(s) independent of the inflammatory response or growth factor up-regulation.
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Brookes MJ, Gibson AM, Hall SD, Furlong PL, Barnes GR, Hillebrand A, Singh KD, Holliday IE, Francis ST, Morris PG. GLM-beamformer method demonstrates stationary field, alpha ERD and gamma ERS co-localisation with fMRI BOLD response in visual cortex. Neuroimage 2005; 26:302-8. [PMID: 15862231 DOI: 10.1016/j.neuroimage.2005.01.050] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2004] [Revised: 12/22/2004] [Accepted: 01/12/2005] [Indexed: 11/30/2022] Open
Abstract
Recently, we introduced a new 'GLM-beamformer' technique for MEG analysis that enables accurate localisation of both phase-locked and non-phase-locked neuromagnetic effects, and their representation as statistical parametric maps (SPMs). This provides a useful framework for comparison of the full range of MEG responses with fMRI BOLD results. This paper reports a 'proof of principle' study using a simple visual paradigm (static checkerboard). The five subjects each underwent both MEG and fMRI paradigms. We demonstrate, for the first time, the presence of a sustained (DC) field in the visual cortex, and its co-localisation with the visual BOLD response. The GLM-beamformer analysis method is also used to investigate the main non-phase-locked oscillatory effects: an event-related desynchronisation (ERD) in the alpha band (8-13 Hz) and an event-related synchronisation (ERS) in the gamma band (55-70 Hz). We show, using SPMs and virtual electrode traces, the spatio-temporal covariance of these effects with the visual BOLD response. Comparisons between MEG and fMRI data sets generally focus on the relationship between the BOLD response and the transient evoked response. Here, we show that the stationary field and changes in oscillatory power are also important contributors to the BOLD response, and should be included in future studies on the relationship between neuronal activation and the haemodynamic response.
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Jain K, Morris PG. A clinical study to evaluate the usefulness of the MAST test in diagnosing pre-labour rupture of membranes. J OBSTET GYNAECOL 2005; 18:33-6. [PMID: 15511998 DOI: 10.1080/01443619868235] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
An open study was performed to evaluate the efficiency of insulin-like growth factor binding protein-1 as a marker for the detection of pre-labour rupture of membranes and to assess whether it aided the subsequent clinical management. One hundred women between 24 and 42 weeks' gestation with a history suggestive of pre-labour rupture of membranes were studied. There were 11 false positive and no false negative results and the sensitivity and specificity were 100% and 89% respectively. The presence of infection, blood or semen did not interfere with the accuracy of the results.
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Ravikumar B, Carey PE, Snaar JEM, Deelchand DK, Cook DB, Neely RDG, English PT, Firbank MJ, Morris PG, Taylor R. Real-time assessment of postprandial fat storage in liver and skeletal muscle in health and type 2 diabetes. Am J Physiol Endocrinol Metab 2005; 288:E789-97. [PMID: 15572652 DOI: 10.1152/ajpendo.00557.2004] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Liver and skeletal muscle triglyceride stores are elevated in type 2 diabetes and correlate with insulin resistance. As postprandial handling of dietary fat may be a critical determinant of tissue triglyceride levels, we quantified postprandial fat storage in normal and type 2 diabetes subjects. Healthy volunteers (n = 8) and diet-controlled type 2 diabetes subjects (n = 12) were studied using a novel 13C magnetic resonance spectroscopy protocol to measure the postprandial increment in liver and skeletal muscle triglyceride following ingestion of 13C-labeled fatty acids given with a standard mixed meal. The postprandial increment in hepatic triglyceride was rapid in both groups (peak increment controls: +7.3 +/- 1.5 mmol/l at 6 h, P = 0.002; peak increment diabetics: +10.8 +/- 3.4 mmol/l at 4 h, P = 0.009). The mean postprandial incremental AUC of hepatic 13C enrichment between the first and second meals (0 and 4 h) was significantly higher in the diabetes group (6.1 +/- 1.4 vs. 1.7 +/- 0.6 mmol x l(-1) x h(-1), P = 0.019). Postprandial increment in skeletal muscle triglyceride in the control group was small compared with the diabetic group, the mean 24-h postprandial incremental AUC being 0.2 +/- 0.3 vs. 1.7 +/- 0.4 mmol x l(-1) x h(-1) (P = 0.009). We conclude that the postprandial uptake of fatty acids by liver and skeletal muscle is increased in type 2 diabetes and may underlie the elevated tissue triglyceride stores and consequent insulin resistance.
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Brookes MJ, Gibson AM, Hall SD, Furlong PL, Barnes GR, Hillebrand A, Singh KD, Holliday IE, Francis ST, Morris PG. A general linear model for MEG beamformer imaging. Neuroimage 2004; 23:936-46. [PMID: 15528094 DOI: 10.1016/j.neuroimage.2004.06.031] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2003] [Revised: 04/14/2004] [Accepted: 06/22/2004] [Indexed: 11/17/2022] Open
Abstract
A new general linear model (GLM) beamformer method is described for processing magnetoencephalography (MEG) data. A standard nonlinear beamformer is used to determine the time course of neuronal activation for each point in a predefined source space. A Hilbert transform gives the envelope of oscillatory activity at each location in any chosen frequency band (not necessary in the case of sustained (DC) fields), enabling the general linear model to be applied and a volumetric T statistic image to be determined. The new method is illustrated by a two-source simulation (sustained field and 20 Hz) and is shown to provide accurate localization. The method is also shown to locate accurately the increasing and decreasing gamma activities to the temporal and frontal lobes, respectively, in the case of a scintillating scotoma. The new method brings the advantages of the general linear model to the analysis of MEG data and should prove useful for the localization of changing patterns of activity across all frequency ranges including DC (sustained fields).
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Abstract
The objective of this study was to quantify the incidence of underlying cervical intraepithelial neoplasia (CIN) among women referred for colposcopy with three consecutive inadequate smears. The design was a retrospective cohort study analysing data from a regional colposcopy database at Cervical Screening Wales. Women who were referred to all the colposcopy clinics in Wales with three consecutive inadequate smears, the third inadequate smear being taken between 1 April 2001 and 31 March 2002 constituted the study population. The results of the fourth smear taken at the colposcopy clinic after three consecutive inadequate smears, the worst biopsy results from any of the subsequent colposcopies and the relationship between the result of the fourth smear taken at colposcopy clinic and any histology result were the main outcome measures. The accuracy of the colposcopic opinion was also examined. Of the 433 women identified as having been referred because of three consecutive inadequate smears, 302 were linked to either a subsequent smear and/or a biopsy result. An adequate smear result was available for 85% of these women when the smear was taken in the colposcopy clinic; 77% were reported as negative and 8% were abnormal. Of the 347 women seen in the colposcopy clinic, high-grade CIN was seen in 3% and low-grade lesion in 8%. The sensitivity and specificity of the fourth inadequate smear test in predicting underlying CIN were 15% and 84% respectively, with a positive predictive value of 8%. The sensitivity and specificity of colposcopy in predicting histological CIN among patients with three inadequate smears was 70% and 49%, respectively, and the positive predictive value was 44%. This study raises the question as to whether three consecutive inadequate smears should be considered as an indication for colposcopy, or merely for a further smear to be taken in circumstances where there is a greater likelihood getting an adequate result.
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Jones NC, Constantin D, Gibson CL, Prior MJW, Morris PG, Marsden CA, Murphy S. A detrimental role for nitric oxide synthase-2 in the pathology resulting from acute cerebral injury. J Neuropathol Exp Neurol 2004; 63:708-20. [PMID: 15290896 DOI: 10.1093/jnen/63.7.708] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Nitric oxide (NO) synthesized from the inducible isoform of nitric oxide synthase (NOS-2) has been suggested to play both beneficial and deleterious roles in various neuropathologies. To define the role of nitric oxide in traumatic brain injury, we subjected male mice lacking a functional NOS-2 gene (NOS-2-/-) and their wild-type littermates (NOS-2+/+) to mild or severe aseptic cryogenic cerebral injury. Expression of NOS-2 mRNA and protein was observed in NOS-2+/+ animals following injury. Lesion volume (as measured by histology and brain imaging) and neurological outcome (using motor and cognitive behavioral paradigms) were assessed at various times after injury. While magnetic resonance imaging revealed the extent of edema of the 2 genotypes to be similar, histology showed a reduced (32%) lesion volume in severely injured NOS-2-/- compared with NOS-2+/+ mice. In addition, NOS-2-/- mice showed significant improvements in both contralateral sensorimotor deficits (grid test: p = 0.011) and cognitive function (Morris water maze: p = 0.009) after severe injury compared to their wild-type littermates. This indicates that lesion volume is reduced and neurological recovery is improved after acute traumatic injury in mice lacking a functional NOS-2 gene, and strongly suggests that the post-trauma production of NO from this source contributes to neuropathology.
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Shah YB, Prior MJW, Dixon AL, Morris PG, Marsden CA. Detection of cannabinoid agonist evoked increase in BOLD contrast in rats using functional magnetic resonance imaging. Neuropharmacology 2004; 46:379-87. [PMID: 14975693 DOI: 10.1016/j.neuropharm.2003.09.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2003] [Revised: 09/12/2003] [Accepted: 09/24/2003] [Indexed: 10/26/2022]
Abstract
BOLD-contrast functional magnetic resonance imaging (fMRI) was used to investigate the effects of the synthetic cannabinoid agonist HU210 on the rat brain in order to determine potential CNS sites of action for the functional effects of cannabinoids. After obtaining basal data, rats (n=8) were given the cannabinoid agonist HU210 (10 microg/kg i.v.) and volume data sets collected for 85 mins. Significant increases in functional BOLD activity were observed in specific brain regions including those important in pain (PAG), reward (VTA and accumbens) and motor function (striatum). In order to confirm cannabinoid receptor involvement in the HU210 evoked functional BOLD activity, rats (n=8) were pre-treated with the CB1 cannabinoid receptor antagonist SR141716A (100 microg/kg i.v.) prior to HU210. Pretreatment with SR141716A abolished all significant evoked HU210 functional BOLD activity. To exclude the involvement of potential systemic effects induced by the cannabinoid agonist administration on the observed evoked functional BOLD activity a separate experiment investigated the effect of HU210 (10 microg/kg i.v.) on mean arterial pressure and showed that HU210 had no significant effect on pressure under chloral hydrate anaesthesia. In summary, this study demonstrates that the cannabinoid agonist HU210 evokes a significant increase in BOLD functional activity in specific regions and that this was cannabinoid receptor mediated. Furthermore the study indicates the potential value of fMRI in rodents to delineate pharmacologically induced changes in regional brain function.
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Swainson R, Cunnington R, Jackson GM, Rorden C, Peters AM, Morris PG, Jackson SR. Cognitive Control Mechanisms Revealed by ERP and fMRI: Evidence from Repeated Task-Switching. J Cogn Neurosci 2003; 15:785-99. [PMID: 14511532 DOI: 10.1162/089892903322370717] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
We investigated the extent to which a common neural mechanism is involved in task set-switching and response withholding, factors that are frequently confounded in taskswitching and go/no-go paradigms. Subjects' brain activity was measured using event-related electrical potentials (ERPs) and event-related functional MRI (fMRI) neuroimaging in separate studies using the same cognitive paradigm. Subjects made compatible left/right keypress responses to left/right arrow stimuli of 1000 msec duration; they switched every two trials between responding at stimulus onset (GO task—green arrows) and stimulus offset (WAIT task—red arrows). Withholding an immediate response (WAIT vs. GO) elicited an enhancement of the frontal N2 ERP and lateral PFC activation of the right hemisphere, both previously associated with the “nogo” response, but only on switch trials. Task-switching (switch vs. nonswitch) was associated with frontal N2 amplification and right hemisphere ventrolateral PFC activation, but only for the WAIT task. The anterior cingulate cortex (ACC) was the only brain region to be activated for both types of task switch, but this activation was located more rostrally for the WAIT than for the GO switch trials. We conclude that the frontal N2 ERP and lateral PFC activation are not markers for withholding an immediate response or switching tasks per se, but are associated with switching into a response-suppression mode. Different regions within the ACC may be involved in two processes integral to task-switching: processing response conflict (rostral ACC) and overcoming prior response suppression (caudal ACC).
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Carey PE, Halliday J, Snaar JEM, Morris PG, Taylor R. Direct assessment of muscle glycogen storage after mixed meals in normal and type 2 diabetic subjects. Am J Physiol Endocrinol Metab 2003; 284:E688-94. [PMID: 12453829 DOI: 10.1152/ajpendo.00471.2002] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To understand the day-to-day pathophysiology of impaired muscle glycogen storage in type 2 diabetes, glycogen concentrations were measured before and after the consumption of sequential mixed meals (breakfast: 190.5 g carbohydrate, 41.0 g fat, 28.8 g protein, 1253 kcal; lunch: 203.3 g carbohydrate, 48.1 g fat, 44.0 g protein, 1497.5 kcal) by use of natural abundance (13)C magnetic resonance spectroscopy. Subjects with diet-controlled type 2 diabetes (n = 9) and age- and body mass index-matched nondiabetic controls (n = 9) were studied. Mean fasting gastrocnemius glycogen concentration was significantly lower in the diabetic group (57.1 +/- 3.6 vs. 68.9 +/- 4.1 mmol/l; P < 0.05). After the first meal, mean glycogen concentration in the control group rose significantly from basal (97.1 +/- 7.0 mmol/l at 240 min; P = 0.005). After the second meal, the high level of muscle glycogen concentration in the control group was maintained, with a further rise to 108.0 +/- 11.6 mmol/l by 480 min. In the diabetic group, the postprandial rise was markedly lower than that of the control group (65.9 +/- 5.2 mmol/l at 240 min, P < 0.005, and 70.8 +/- 6.7 mmol/l at 480 min, P = 0.01) despite considerably greater serum insulin levels (752.0 +/- 109.0 vs. 372.3 +/- 78.2 pmol/l at 300 min, P = 0.013). This was associated with a significantly greater postprandial hyperglycemia (10.8 +/- 1.3 vs. 5.3 +/- 0.2 mmol/l at 240 min, P < 0.005). Basal muscle glycogen concentration correlated inversely with fasting blood glucose (r = -0.55, P < 0.02) and fasting serum insulin (r = -0.57, P < 0.02). The increment in muscle glycogen correlated with initial increment in serum insulin only in the control group (r = 0.87, P < 0.002). This study quantitates for the first time the subnormal basal muscle glycogen concentration and the inadequate glycogen storage after meals in type 2 diabetes.
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Abstract
The use of functional magnetic resonance imaging (fMRI) to follow random or serial sequences of neural activity is explored and illustrated with examples that include auditory hallucinations and a short-term memory paradigm. Despite the availability of ultra-high-speed fMRI sequences, the inherent latency of the haemodynamic response limits the time resolution of fMRI studies. To access finer time-scales, it can be combined with electromagnetic techniques (MEG or EEG). Functional magnetic resonance spectroscopy (MRS) studies, in which infusion of [1-(13)C]glucose enables rates of the tricarboxylic acid cycle to be determined, demonstrates substantial (50%) increases in this flux on visual activation. Not only does this provide a quantitative estimate of the energy cost of brain activation, it also shows that the extra glucose is consumed essentially oxidatively. In the same studies, measurements of the rate of glutamine synthesis, enable the rate of recycling of neurotransmitter glutamate to be estimated.
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Alwatban AZ, Ludman CN, Mason SM, O'Donoghue GM, Peters AM, Morris PG. A method for the direct electrical stimulation of the auditory system in deaf subjects: a functional magnetic resonance imaging study. J Magn Reson Imaging 2002; 16:6-12. [PMID: 12112497 DOI: 10.1002/jmri.10126] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To develop a safe functional magnetic resonance imaging (fMRI) procedure for auditory assessment of deaf subjects. MATERIALS AND METHODS A gold-plated tungsten electrode has been developed which has zero magnetic susceptibility. Used with carbon leads and a carbon reference pad, it enables safe, distortion-free fMRI studies of deaf subjects following direct electrical stimulation of the acoustic nerve. Minor pickup of the radio frequency (RF) pulses by the electrode assembly is difficult to eliminate, and a SPARSE acquisition sequence is used to avoid any effects of unintentional auditory nerve stimulation. RESULTS The procedure is demonstrated in a deaf volunteer. Activation is observed in the contralateral but not the ipsilateral primary auditory cortex. This is in sharp contrast to studies of auditory processing in hearing subjects, but consistent with the small number of previous positron emission tomography (PET) and MR studies on adult deaf subjects. CONCLUSION The fMRI procedure is able to demonstrate whether the auditory pathway is fully intact, and may provide a useful method for preoperative assessment of candidates for cochlear implantation.
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Thatcher NM, Badar-Goffer RS, Ben-Yoseph O, McLean MA, Morris PG, Prior MJW, Taylor A, Bachelard HS. A comparison of some metabolic effects of N-methylaspartate stereoisomers, glutamate and depolarization: a multinuclear MRS study. Neurochem Res 2002; 27:51-8. [PMID: 11930910 DOI: 10.1023/a:1014898421330] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Exposure of guinea pig brain slices to low concentrations (10 microM) of NMDA caused decreases in PCr and ATP within 30 min, with a slower decrease in NAA and increase in lactate, both detectable after 1 h. Exposure to NMDA for over 1 h or at higher concentrations caused further increases in lactate and decreases in NAA, with no further change in PCr or ATP. The L-isomer, NMLA, and the racemic mixture, NMDLA, caused similar changes in lactate and NAA, but both produced greater decreases in the energy state than NMDA, similar to those caused by prolonged exposure to glutamate. MK-801 prevented the changes in the energy state caused by NMDA, but not those caused by NMLA or by glutamate. The results are compared to previous studies on depolarization and discussed in terms of the role of the NMDA sub-type of glutamate receptor in the excitotoxic hypothesis of neuronal degeneration.
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Chhina N, Kuestermann E, Halliday J, Simpson LJ, Macdonald IA, Bachelard HS, Morris PG. Measurement of human tricarboxylic acid cycle rates during visual activation by (13)C magnetic resonance spectroscopy. J Neurosci Res 2001; 66:737-46. [PMID: 11746397 DOI: 10.1002/jnr.10053] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Measurement by (13)C magnetic resonance spectroscopy (MRS) of the incorporation of label from [1-(13)C] glucose, initially into C4 of glutamate, allows the regional tricarboxylic acid (TCA) cycle flux (F(TCA)) to be determined in the human brain. In this study, a direct (13)C MRS approach was used at 3T, with NOE enhancement and (1)H decoupling with WALTZ16, to determine basal F(TCA) in six volunteers. The values found in the visual cortex are similar to those reported in previous (13)C MRS studies, and consistent with PET measurements of the cerebral metabolic rate for glucose, CMRglc. In two preliminary activation studies using light emitting diode (LED) goggles flashing at 8 Hz, compared to darkness as control, increases in F(TCA) were found from 0.60 +/- 0.10 to 0.94 +/- 0.03 micromol/min/g (56%) and from 0.34 +/- 0.14 to 0.56 +/- 0.07 micromol/min/g (65%). These are upper estimates, but they are similar to the increases in CMRglc reported in PET studies, and strongly suggest, in contrast to these PET studies, that cerebral glucose is metabolized oxidatively, even during intense visual stimulation. This is supported by the observation that very little (13)C label is incorporated into C3 lactate, as would be expected if glucose were metabolized anaerobically. There is evidence for incorporation of glucose into cerebral glycogen, but this is a relatively minor component of cerebral glucose metabolism.
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Clare S, Francis S, Morris PG, Bowtell R. Single-shot T2(*) measurement to establish optimum echo time for fMRI: studies of the visual, motor, and auditory cortices at 3.0 T. Magn Reson Med 2001; 45:930-3. [PMID: 11323822 DOI: 10.1002/mrm.1124] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The signal change in fMRI is dependent on the echo time and the rate of decay of transverse magnetization. The latter factor may vary across regions of the brain as a result of variations in field homogeneity. Previous measurements of the signal change with echo time have generally employed relatively slow multi-echo techniques, which may be sensitive to movement and habituation effects. Here a fast T(2)(*) measurement technique, involving the generation of six low-resolution echo planar images from a single FID, is described, and its use in the evaluation of the optimum echo time for visual, motor, and auditory fMRI experiments at 3.0 T is outlined.
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Frenkiel TA, Jasinski A, Morris PG. Apparatus for generation of magnetic field gradient waveforms for NMR imaging. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0022-3735/21/4/007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Lennox BR, Park SB, Medley I, Morris PG, Jones PB. The functional anatomy of auditory hallucinations in schizophrenia. Psychiatry Res 2000; 100:13-20. [PMID: 11090721 DOI: 10.1016/s0925-4927(00)00068-8] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We used continuous whole brain functional magnetic resonance imaging (fMRI) with a 3-T magnet to map the cerebral activation associated with auditory hallucinations in four subjects with schizophrenia. The subjects experienced episodes of hallucination whilst in the scanner so that periods of hallucination could be compared with periods of rest in the same individuals. Group analysis demonstrated shared areas of activation in right and left superior temporal gyri, left inferior parietal cortex and left middle frontal gyrus. When the data were examined on an individual basis, the temporal cortex and prefrontal cortex areas were activated during episodes of hallucination in all four subjects. These findings support the theory that auditory hallucination reflects abnormal activation of normal auditory pathways.
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Ludman CN, Summerfield AQ, Hall D, Elliott M, Foster J, Hykin JL, Bowtell R, Morris PG. Lip-reading ability and patterns of cortical activation studied using fMRI. BRITISH JOURNAL OF AUDIOLOGY 2000; 34:225-30. [PMID: 10997451 DOI: 10.3109/03005364000000132] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Lip-reading is a complex cognitive skill with large individual differences in performance. The basis of these individual differences remains poorly understood. Functional magnetic resonance imaging (fMRI) techniques allows brain activation accompanying complex cognitive activities to be studied noninvasively. In the present paper, fMRI was used to study the patterns of cortical activation that occur during the silent lip-reading of connected speech and to investigate whether there are detectable differences in activation between subjects with widely differing lip-reading abilities. From a cohort of 26 volunteers, nine subjects who fell into three distinct lip-reading ability groups were selected. Brain activation was measured in two conditions: an experimental condition where subjects attempted to lip-read sentences; and a baseline condition where subjects passively viewed a static image of a talker's face. Relative to the baseline condition, lip-reading induced activation in several cortical areas, including the auditory cortices, despite the lack of an auditory component to the task. In comparison to the better two groups of lip-readers, subjects in the poorest group displayed significantly less activation in superior and middle temporal gyrus, but not inferior temporal gyrus. These preliminary results justify more extensive investigations of the cortical basis of individual differences in lip-reading.
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Casey A, Mann R, Banister K, Fox J, Morris PG, Macdonald IA, Greenhaff PL. Effect of carbohydrate ingestion on glycogen resynthesis in human liver and skeletal muscle, measured by (13)C MRS. Am J Physiol Endocrinol Metab 2000; 278:E65-75. [PMID: 10644538 DOI: 10.1152/ajpendo.2000.278.1.e65] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study investigated the effect of carbohydrate (CHO) ingestion on postexercise glycogen resynthesis, measured simultaneously in liver and muscle (n = 6) by (13)C magnetic resonance spectroscopy, and subsequent exercise capacity (n = 10). Subjects cycled at 70% maximal oxygen uptake for 83 +/- 8 min on six separate occasions. At the end of exercise, subjects ingested 1 g/kg body mass (BM) glucose, sucrose, or placebo (control). Resynthesis of glycogen over a 4-h period after treatment ingestion was measured on the first three occasions, and subsequent exercise capacity was measured on occasions four through six. No glycogen was resynthesized during the control trial. Liver glycogen resynthesis was evident after glucose (13 +/- 8 g) and sucrose (25 +/- 5 g) ingestion, both of which were different from control (P < 0.01). No significant differences in muscle glycogen resynthesis were found among trials. A relationship between the CHO load (g) and change in liver glycogen content (g) was evident after 30, 90, 150, and 210 min of recovery (r = 0.59-0. 79, P < 0.05). Furthermore, a modest relationship existed between change in liver glycogen content (g) and subsequent exercise capacity (r = 0.53, P < 0.05). However, no significant difference in mean exercise time was found (control: 35 +/- 5, glucose: 40 +/- 5, and sucrose: 46 +/- 6 min). Therefore, 1 g/kg BM glucose or sucrose is sufficient to initiate postexercise liver glycogen resynthesis, which contributes to subsequent exercise capacity, but not muscle glycogen resynthesis.
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Morris PG. Magnetic resonance imaging and magnetic resonance spectroscopy assessment of brain function in experimental animals and man. J Psychopharmacol 1999; 13:330-6. [PMID: 10667608 DOI: 10.1177/026988119901300403] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This paper introduces the basic principles and techniques of functional magnetic resonance imaging (fMRI) and spectroscopy (MRS). Examples are given of single event human fMRI studies on control subjects, and a graded activation protocol applied to Parkinsonian patients. Possibilities are discussed for using fMRI techniques to study the neural substrate of various pharmacological agents, including drugs of abuse. The application of these pharmacological MRI (phMRI) studies to animal models and the associated technical issues are also addressed. The use of MRS in studying brain status and function is reviewed, with particular emphasis on 13C isotopic labelling studies.
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