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Shah M, Xiao Y, Subbanna N, Francis S, Arnold DL, Collins DL, Arbel T. Evaluating intensity normalization on MRIs of human brain with multiple sclerosis. Med Image Anal 2010; 15:267-82. [PMID: 21233004 DOI: 10.1016/j.media.2010.12.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 12/03/2010] [Accepted: 12/13/2010] [Indexed: 10/18/2022]
Abstract
Intensity normalization is an important pre-processing step in the study and analysis of Magnetic Resonance Images (MRI) of human brains. As most parametric supervised automatic image segmentation and classification methods base their assumptions regarding the intensity distributions on a standardized intensity range, intensity normalization takes on a very significant role. One of the fast and accurate approaches proposed for intensity normalization is that of Nyul and colleagues. In this work, we present, for the first time, an extensive validation of this approach in real clinical domain where even after intensity inhomogeneity correction that accounts for scanner-specific artifacts, the MRI volumes can be affected from variations such as data heterogeneity resulting from multi-site multi-scanner acquisitions, the presence of multiple sclerosis (MS) lesions and the stage of disease progression in the brain. Using the distributional divergence criteria, we evaluate the effectiveness of the normalization in rendering, under the distributional assumptions of segmentation approaches, intensities that are more homogenous for the same tissue type while simultaneously resulting in better tissue type separation. We also demonstrate the advantage of the decile based piece-wise linear approach on the task of MS lesion segmentation against a linear normalization approach over three image segmentation algorithms: a standard Bayesian classifier, an outlier detection based approach and a Bayesian classifier with Markov Random Field (MRF) based post-processing. Finally, to demonstrate the independence of the effectiveness of normalization from the complexity of segmentation algorithm, we evaluate the Nyul method against the linear normalization on Bayesian algorithms of increasing complexity including a standard Bayesian classifier with Maximum Likelihood parameter estimation and a Bayesian classifier with integrated data priors, in addition to the above Bayesian classifier with MRF based post-processing to smooth the posteriors. In all relevant cases, the observed results are verified for statistical relevance using significance tests.
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Derakhshan M, Caramanos Z, Giacomini PS, Narayanan S, Maranzano J, Francis SJ, Arnold DL, Collins DL. Evaluation of automated techniques for the quantification of grey matter atrophy in patients with multiple sclerosis. Neuroimage 2010; 52:1261-7. [DOI: 10.1016/j.neuroimage.2010.05.029] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 04/16/2010] [Accepted: 05/12/2010] [Indexed: 11/28/2022] Open
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Godfrey SAC, Mansfield JW, Corry DS, Lovell HC, Jackson RW, Arnold DL. Confocal imaging of Pseudomonas syringae pv. phaseolicola colony development in bean reveals reduced multiplication of strains containing the genomic island PPHGI-1. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:1294-1302. [PMID: 20672876 DOI: 10.1094/mpmi-05-10-0114] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Pseudomonas syringae pv. phaseolicola is the seed borne causative agent of halo blight in the common bean Phaseolus vulgaris. Pseudomonas syringae pv. phaseolicola race 4 strain 1302A contains the avirulence gene hopAR1 (located on a 106-kb genomic island, PPHGI-1, and earlier named avrPphB), which matches resistance gene R3 in P. vulgaris cultivar Tendergreen (TG) and causes a rapid hypersensitive reaction (HR). Here, we have fluorescently labeled selected Pseudomonas syringae pv. phaseolicola 1302A and 1448A strains (with and without PPHGI-1) to enable confocal imaging of in-planta colony formation within the apoplast of resistant (TG) and susceptible (Canadian Wonder [CW]) P. vulgaris leaves. Temporal quantification of fluorescent Pseudomonas syringae pv. phaseolicola colony development correlated with in-planta bacterial multiplication (measured as CFU/ml) and is, therefore, an effective means of monitoring Pseudomonas syringae pv. phaseolicola endophytic colonization and survival in P. vulgaris. We present advances in the application of confocal microscopy for in-planta visualization of Pseudomonas syringae pv. phaseolicola colony development in the leaf mesophyll to show how the HR defense response greatly affects colony morphology and bacterial survival. Unexpectedly, the presence of PPHGI-1 was found to cause a reduction of colony development in susceptible P. vulgaris CW leaf tissue. We discuss the evolutionary consequences that the acquisition and retention of PPHGI-1 brings to Pseudomonas syringae pv. phaseolicola in planta.
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Narayanan S, Carmel-Veilleux A, Araújo D, Chen J, Arnold DL. P2‐449: Precision of longitudinal measures of cortical grey matter thickness change and ventricular volume change: comparison to the difference of cross‐sectional measures, using multicenter scan‐reposition‐rescan MRI data. Alzheimers Dement 2010. [DOI: 10.1016/j.jalz.2010.08.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Narayanan S, Carmel-Veilleux A, Araújo D, Chen J, Arnold DL. IC‐P‐055: Precision of Longitudinal Measures of Cortical Grey Matter Thickness Change and Ventricular Volume Change: Comparison to the Difference of Cross‐Sectional Measures, Using Multicenter Scan‐Reposition‐Rescan MRI Data. Alzheimers Dement 2010. [DOI: 10.1016/j.jalz.2010.05.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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231
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Fonov VS, Arnold DL, Collins DL. P1‐397: Robust automatic segmentation and characterization of lateral ventricle size in the ADNI cohort. Alzheimers Dement 2010. [DOI: 10.1016/j.jalz.2010.05.951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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232
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Dudani A, Ghassemi R, Narayanan S, Arnold DL, Sled JG, Banwell B, Till C. Pediatric Multiple Sclerosis and Executive Function. Paediatr Child Health 2010. [DOI: 10.1093/pch/15.suppl_a.60ab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Pasquini MC, Griffith LM, Arnold DL, Atkins HL, Bowen JD, Chen JT, Freedman MS, Kraft GH, Mancardi GL, Martin R, Muraro PA, Nash RA, Racke MK, Storek J, Saccardi R. Hematopoietic stem cell transplantation for multiple sclerosis: collaboration of the CIBMTR and EBMT to facilitate international clinical studies. Biol Blood Marrow Transplant 2010; 16:1076-83. [PMID: 20304084 DOI: 10.1016/j.bbmt.2010.03.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Accepted: 03/10/2010] [Indexed: 12/29/2022]
Abstract
Clinical investigation of autologous hematopoietic stem cell transplantation (HSCT) as therapy for multiple sclerosis (MS) has been ongoing for over a decade. While several phase II studies have been finalized or are in progress, no definitive prospective randomized studies comparing HSCT versus alternative therapies for MS have been completed. In this conference report of North American and European experts who are involved in the care of MS patients, including neurologists and HSCT physicians, and representatives of the Center for International Blood and Marrow Transplant Research (CIBMTR) and European Group for Blood and Marrow Transplantation (EBMT), we (1) critically review progress to date in HSCT for MS; (2) describe current registry based projects including long-term follow-up studies in HSCT for MS and harmonization of the MS disease-specific research forms that will be used in future by both databases; (3) discuss challenges in study design for a prospective randomized clinical trial of HSCT versus alternative therapy for MS such as feasibility, and the importance of multidisciplinary clinical teams, need for a large sample size and duration of observation required for outcomes assessment; and (4) address future directions in HSCT therapy for MS. To undertake a definitive multicenter clinical trial in autologous HSCT for MS, it will be important to begin well in advance to assemble the team, evaluate proposals for study design, and consider options for the infrastructure and logistical support that will be needed. International collaboration, including partnership with the CIBMTR and EBMT, may be desirable and may in fact be critical for successful completion of a definitive comparative study.
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Johnson KP, Fox RJ, Arnold DL. Seeing injectable ms therapies differently: they are more similar than different. Neurology 2010; 74:702. [PMID: 20177129 DOI: 10.1212/wnl.0b013e3181c77773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Caramanos Z, Fonov VS, Francis SJ, Narayanan S, Pike GB, Collins DL, Arnold DL. Corrigendum to “Gradient distortions in MRI: Characterizing and correcting for their effects on SIENA-generated measures of brain volume change” [NeuroImage 49 (2010) 1601–1611]. Neuroimage 2010. [DOI: 10.1016/j.neuroimage.2009.12.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Fonov VS, Janke A, Caramanos Z, Arnold DL, Narayanan S, Pike GB, Collins DL. Improved Precision in the Measurement of Longitudinal Global and Regional Volumetric Changes via a Novel MRI Gradient Distortion Characterization and Correction Technique. LECTURE NOTES IN COMPUTER SCIENCE 2010. [DOI: 10.1007/978-3-642-15699-1_34] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Caramanos Z, Fonov VS, Francis SJ, Narayanan S, Pike GB, Collins DL, Arnold DL. Gradient distortions in MRI: Characterizing and correcting for their effects on SIENA-generated measures of brain volume change. Neuroimage 2010; 49:1601-11. [DOI: 10.1016/j.neuroimage.2009.08.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 06/22/2009] [Accepted: 08/05/2009] [Indexed: 11/30/2022] Open
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Kemp AS, Grossberg GT, Romano SJ, Arnold DL, Ryan JM, Bullock R, Streiner DL. Trial designs likely to meet valid long-term Alzheimer's disease progression effects: learning from the past, preparing for the future. Int J Alzheimers Dis 2009; 2009. [PMID: 20798873 PMCID: PMC2925210 DOI: 10.4061/2009/949271] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Accepted: 09/21/2009] [Indexed: 11/25/2022] Open
Abstract
The International Society for CNS Clinical Trials and Methodology (ISCTM) held its 4th Annual Autumn Conference in Toronto, Ontario, October 6-7, 2008. The purpose of the present report is to provide an overview of one of the sessions at the conference which focused on the designs and methodologies to be applied in clinical trials of new treatments for Alzheimer's disease (AD) with purported “disease-modifying” effects. The session began with a discussion of how neuroimaging has been applied in multiple sclerosis clinical trials (another condition for which disease modification claims have been achieved). The next two lectures provided a pharmaceutical industry perspective on some of the specific challenges and possible solutions for designing trials to measure disease progression and/or modification. The final lecture provided an academic viewpoint and the closing discussion included additional academic and regulatory perspectives on trial designs, methodologies, and statistical issues relevant to the disease modification concept.
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Trojan DA, Arnold DL, Shapiro S, Bar-Or A, Robinson A, Le Cruguel JP, Narayanan S, Tartaglia MC, Caramanos Z, Da Costa D. Fatigue in post-poliomyelitis syndrome: association with disease-related, behavioral, and psychosocial factors. PM R 2009; 1:442-9. [PMID: 19627931 DOI: 10.1016/j.pmrj.2009.03.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2008] [Revised: 02/26/2009] [Accepted: 03/08/2009] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To determine the biopsychosocial correlates of general, physical, and mental fatigue in patients with postpoliomyelitis syndrome (PPS) by assessing the additional contribution of potentially modifiable factors after accounting for important nonmodifiable disease-related factors. It was hypothesized that disease-related, behavioral, and psychosocial factors would contribute in different ways to general, physical, and mental fatigue in PPS and that a portion of fatigue would be determined by potentially modifiable factors. DESIGN Cross-sectional study. SETTING A tertiary university-affiliated hospital post-polio clinic. PATIENTS Fifty-two ambulatory patients with PPS who were not severely depressed were included. ASSESSMENT OF RISK FACTORS Potential correlates for fatigue included disease-related factors (acute polio weakness, time since acute polio, PPS duration, muscle strength, pain, forced vital capacity, maximum inspiratory pressure, maximum expiratory pressure, body mass index, disability, fibromyalgia), behavioral factors (physical activity, sleep quality), and psychosocial factors (depression, stress, self-efficacy). MAIN OUTCOME MEASUREMENTS Fatigue was assessed with the Multidimensional Fatigue Inventory (MFI; assesses fatigue on 5 subscales) and the Fatigue Severity Scale (FSS). RESULTS Multivariate models were computed for MFI General, Physical, and Mental Fatigue. Age-adjusted multivariate models with nonmodifiable factors included the following predictors of (1) MFI General Fatigue: maximum inspiratory pressure, fibromyalgia, muscle strength; (2) MFI Physical Fatigue: maximum expiratory pressure, muscle strength, age, time since acute polio; and (3) MFI Mental Fatigue: none. The following potentially modifiable predictors made an additional contribution to the models: (1) MFI General Fatigue: stress, depression; (2) MFI Physical Fatigue: physical activity, pain; and (3) MFI Mental Fatigue: stress. CONCLUSIONS PPS fatigue is multidimensional. Different types of fatigue are determined by different variables. Potentially modifiable factors account for a portion of fatigue in PPS.
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Bar-Or A, Oger J, Gibbs E, Niino M, Aziz T, Renoux C, Alatab S, Shi FD, Campagnolo D, Jalili F, Rhodes S, Yamashita T, Fan B, Freedman MS, Panitch H, Arnold DL, Vollmer T. Serial combination therapy: is immune modulation in multiple sclerosis enhanced by initial immune suppression? Mult Scler 2009; 15:959-64. [DOI: 10.1177/1352458509106230] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background Although the concept that an initial course of immune-suppression facilitates subsequent immune-modulation (such as Th1 to Th2 deviation) is attractive for several autoimmune diseases, such a mechanism for serial-combination therapy has never been formally demonstrated. Recently, brief mitoxantrone induction-chemotherapy followed by immune-modulation with glatiramer acetate (GA) was significantly more effective at reducing multiple sclerosis disease activity than with GA alone. Objective To examine whether the benefit of initial immune suppression with mitoxantrone before GA treatment is associated with more efficient immune modulation. Methods IgG1/IgG4 GA-reactive antibody profiles, previously established as markers of GA-induced Th2 immune-deviation, were prospectively measured in vivo in patients treated with GA alone or with mitoxantrone induction therapy followed by GA. Results Significant and sustained increase in IgG4 antibodies (and the anticipated reversal of the IgG1/IgG4 ratio) was seen in patients treated with GA alone. Combination therapy resulted in lesser IgG4 induction (and no reversal of IgG1/IgG4 ratio). Thus, the enhanced efficacy of mitoxantrone–GA combination regimen was associated with decreased, rather than increased, efficiency of shifting the GA-reactive IgG1/IgG4 antibody profile. Conclusion These results provide important insights into mechanisms of combination therapy and therapeutic strategies for autoimmune diseases.
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Mehta LR, Schwid SR, Arnold DL, Cutter GR, Aradhye S, Balcer LJ, Calabresi PA, Cohen JA, Cole PE, Glanzman R, Goelz S, Inglese M, Kapoor R, Kappos L, Kreitman R, Lublin FD, Mann A, Marrie RA, O'Looney P, Polman CH, Ravina BM, Reingold SC, Richert JR, Sandrock AW, Waubant E. Proof of concept studies for tissue-protective agents in multiple sclerosis. Mult Scler 2009; 15:542-6. [PMID: 19389749 DOI: 10.1177/1352458508101939] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND There is considerable interest in tissue-protective treatments for multiple sclerosis (MS). METHODS AND OBJECTIVES We convened a group of MS clinical trialists and related researchers to discuss designs for proof of concept studies utilizing currently available data and assessment methods. RESULTS Our favored design was a randomized, double-blind, parallel-group study of active treatment versus placebo focusing on changes in brain volume from a post-baseline scan (3-6 months after starting treatment) to the final visit 1 year later. Study designs aimed at reducing residual deficits following acute exacerbations are less straightforward, depending greatly on the anticipated rapidity of treatment effect onset. CONCLUSIONS The next step would be to perform one or more studies of potential tissue-protective agents with these designs in mind, creating the longitudinal data necessary to refine endpoint selection, eligibility criteria, and sample size estimates for future trials.
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Caramanos Z, Fonov V, Francis SJ, Narayanan S, Collins DL, Arnold DL. P2‐020: The effect of head positioning and repositioning on SIENA‐generated measures of brain volume change: Results from Simulated Z‐shifts. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.04.329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Collins DL, Maranzano J, Li T, Arnold DL. O2‐01‐07: Robust automatic segmentation of hippocampus from multisite MRI data. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.05.322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Caramanos Z, Fonov V, Francis SJ, Narayanan S, Collins DL, Arnold DL. P2‐019: The effect of head positioning and repositioning on SIENA‐generated measures of brain volume change: Results from actual Z‐shifts. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.04.328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Caramanos Z, Fonov V, Francis SJ, Narayanan S, Collins DL, Arnold DL. IC‐P‐134: The effect of head positioning and repositioning on SIENA‐generated measures of brain volume change: Results from actual Z‐shifts. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.05.106] [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]
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Caramanos Z, Fonov V, Francis SJ, Narayanan S, Collins DL, Arnold DL. IC‐P‐135: The effect of head positioning and repositioning on SIENA‐generated measures of brain volume change: Results from simulated Z‐shifts. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.05.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Trojan DA, Arnold DL, Shapiro S, Bar-Or A, Robinson A, Le Cruguel JP, Narayanan S, Tartaglia MC, Caramanos Z, Da Costa D. Fatigue in Post-poliomyelitis Syndrome: Association With Disease-Related, Behavioral, and Psychosocial Factors. PM R 2009. [DOI: 10.1016/j.pmrj.2009.03.003 10.1016/j.pmrj.2009.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Fox RJ, Arnold DL. Seeing injectable MS therapies differently: they are more similar than different. Neurology 2009; 72:1972-3. [PMID: 19439722 DOI: 10.1212/wnl.0b013e3181a92c82] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Giacomini PS, Levesque IR, Ribeiro L, Narayanan S, Francis SJ, Pike GB, Arnold DL. Measuring demyelination and remyelination in acute multiple sclerosis lesion voxels. ACTA ACUST UNITED AC 2009; 66:375-81. [PMID: 19273757 DOI: 10.1001/archneurol.2008.578] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To validate the use of the magnetization transfer ratio (MTR) as a practical imaging marker of demyelination and remyelination in acute multiple sclerosis lesions. DESIGN Case study. SETTING University hospital multiple sclerosis clinic. Patients Six patients with relapsing-remitting multiple sclerosis and acute gadolinium-enhancing lesions were studied serially using a quantitative magnetization transfer examination. MAIN OUTCOME MEASURES Changes in the water content and macromolecular content, a marker of myelin content that, unlike MTR, is not affected by changes in water content (edema) associated with acute inflammation, and changes in MTR of lesions. RESULTS Both the macromolecular content and MTR were lower than normal in acute lesions and recovered over several months. The decrease in macromolecular content relative to contralateral normal-appearing white matter was greater than the decrease in MTR (0.46 vs 0.75 at the time of gadolinium enhancement), likely because edema in the acute lesion increased the T1 relaxation time of water and attenuated the decrease in MTR. Nevertheless, there was still a strong correlation between changes in the relative MTR and macromolecular content (R(2) = 0.70; P < .001). CONCLUSION Our data support the use of MTR as a practical marker of demyelination and remyelination, even in acute lesions where decreases in MTR are attenuated because of the effects of edema.
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Doucet J, Tague B, Arnold DL, Cooke GM, Hayward S, Goodyer CG. Persistent organic pollutant residues in human fetal liver and placenta from Greater Montreal, Quebec: a longitudinal study from 1998 through 2006. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:605-10. [PMID: 19440500 PMCID: PMC2679605 DOI: 10.1289/ehp.0800205] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 12/10/2008] [Indexed: 05/07/2023]
Abstract
BACKGROUND There is general concern that persistent organic pollutants (POPs) found in the environment, wildlife, food, water, house dust, human tissues, and fluids may alter normal human physiologic activities (e.g., fetal development, immune and endocrine systems). Although the levels of some POPs [polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs)] in these matrices have decreased after their ban, others [polybrominated diphenyl ethers (PBDEs)] have increased in recent years. OBJECTIVE To determine the longitudinal trend of specific POPs in human fetal tissues for risk assessment purposes. METHODS We analyzed early to mid-gestation fetal liver (n = 52) and placental (n = 60) tissues, obtained after elective abortions during 1998-2006, for selected PBDEs, PCBs, and OCs using gas chromatography-mass spectroscopy. RESULTS Total PBDEs in fetal liver increased over time (mean +/- SE: 1998, 284.4 +/- 229.8 ng/g lipid; 2006, 1,607.7 +/- 605.9; p < 0.03), whereas placental levels were generally lower, with no clear trend. Low levels of PCBs and OCs varied yearly, with no evident trend. The major analytes in 1998 were OCs (liver, 49%; placenta, 71%), whereas the major analytes in 2006 were PBDEs (liver, 89%; placenta, 98%). The 1998-2006 tissue PBDE congener profile is similar to that of DE-71, a commercial primarily pentabrominated diphenyl ether mixture manufactured in North America. CONCLUSIONS Although commercial production of penta- and octa-brominated diphenyl ethers in North America was halted in 2004, their concentrations in fetal liver and placenta are now greater than the tissue burdens for the analyzed OCs and PCBs. Our findings also demonstrate that PBDEs accumulate within the fetal compartment at a very early stage in gestation.
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