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Dive into the research topics where Edward S. Johnson is active.

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Featured researches published by Edward S. Johnson.


Annals of Neurology | 2008

Mutations in TPM3 are a common cause of congenital fiber type disproportion

Nigel F. Clarke; Hannah Kolski; Danielle E. Dye; Esther Lim; Robert L. Smith; Rakesh Patel; Michael Fahey; Remi Bellance; Norma B. Romero; Edward S. Johnson; Annick Labarre-Vila; Nicole Monnier; Nigel G. Laing; Kathryn N. North

Congenital fiber type disproportion (CFTD) is a rare form of congenital myopathy in which the principal histological abnormality is hypotrophy of type 1 (slow‐twitch) fibers compared with type 2 (fast‐twitch) fibers. To date, mutation of ACTA1 and SEPN1 has been associated with CFTD, but the genetic basis in most patients is unclear. The gene encoding α‐tropomyosinslow (TPM3) is a rare cause of nemaline myopathy, previously reported in only five families. We investigated whether mutation of TPM3 is a cause of CFTD.


International Journal of Radiation Oncology Biology Physics | 1984

Misonidazole combined with hyperfractionation in the management of malignant glioma

Dorcas Fulton; Raul C. Urtasun; Kyu H. Shin; Peter H.S. Geggie; H. Thomas; Paul J. Muller; J. Moody; Hilary Tanasichuk; Bruce Mielke; Edward S. Johnson; B. Curry

Multiple daily fractionated radiation therapy (MDF) may be more effective than conventionally fractionated radiation therapy (CF) in the treatment of malignant glioma. The hypoxic cell sensitizer misonidazole (MISO) could be more effective when employed with small fractions of radiation every 4 hours to take advantage of the long half-life of the drug. To evaluate MDF and MDF in combination with MISO, a randomized prospective trial was initiated. Between January 1981, and December 1982, patients with histologically verified astrocytoma with anaplastic foci or glioblastoma multiforme were randomized to CF (5800 cGy, 30 fractions, 6 weeks), MDF (6141 cGy, 69 fractions, 4 1/2 weeks, at 89 cGy every 4 hours 3 times daily) and MDF in combination with MISO (1.25 gm/M2 three times weekly for the first 3 weeks). In January 1983, the CF arm was dropped and a high dose MDF arm added (7120 cGy, 80 fractions, 5 1/2 weeks, at 89 cGy per fraction every 4 hours 3 times daily). CCNU chemotherapy was given at the time of tumor progression. One hundred and twenty-eight patients were evaluated (38 CF, 42 MDF, 37 MDF plus MISO, and 11 high dose MDF). Median survival was 29 weeks for CF, 45 weeks for MDF and 50 weeks for MDF plus MISO. Survival was significantly improved for patients treated with MDF compared to patients treated with CF (p less than .002). The addition of MISO to MDF did not result in further improvement in survival. Acute toxicity was acceptable. No clinically apparent delayed toxicity was observed.


Radiology | 2013

Multiple Sclerosis: Validation of MR Imaging for Quantification and Detection of Iron

Andrew J. Walsh; R. Marc Lebel; Amir Eissa; Gregg Blevins; Ingrid Catz; Jian-Qiang Lu; Lothar Resch; Edward S. Johnson; Derek Emery; Kenneth G. Warren; Alan H. Wilman

PURPOSE To investigate the relationship between iron staining and magnetic resonance (MR) imaging measurements in postmortem subjects with multiple sclerosis (MS). MATERIALS AND METHODS Institutional ethical approval was obtained, and informed consent was obtained from the subjects and/or their families. Four MR imaging methods based on transverse relaxation (T2 weighting, R2 mapping, and R2* mapping) and phase imaging were performed by using a 4.7-T system in three in situ postmortem patients with MS less than 28 hours after death and in one in vivo patient 1 year before death. Iron staining with the Perls iron reaction was performed after brain extraction. Region-of-interest measurements from six subcortical gray matter structures were obtained from MR imaging and then correlated with corresponding locations on photographs of iron-stained pathologic slices by using a separate linear least-squares regression in each subject. Iron status of white matter lesions, as determined by staining, was compared with appearance on MR images. RESULTS R2* mapping had the highest intrasubject correlations with iron in subcortical gray matter (R(2) = 0.857, 0.628, and 0.685; all P < .001), while R2 mapping (R(2) = 0.807, 0.615, 0.628, and 0.489; P < .001 and P = .001, .034, and .001, respectively), phase imaging (R(2) = 0.672, 0.441, 0.596, 0.548; all P ≤ .001), and T2-weighted imaging (R(2) = 0.463, 0.582, 0.650, and 0.551; all P < .001) had lower but still strong correlations. Within lesions, hypointense areas on phase images did not always represent iron. A hyperintense rim surrounding lesions on R2* maps was only present with iron staining, yet not all iron-staining lesions had R2* rim hyperintensity. CONCLUSION All four MR imaging methods had significant linear correlations with iron and could potentially be used to determine iron status of subcortical gray matter structures in MS, with R2* mapping being preferred. A reliable method of determining iron status within MS lesions was not established.


Cancer | 1985

Multiple daily fractionated radiation therapy and misonidazole in the management of malignant astrocytoma. A preliminary report

Kyu H. Shin; Raul C. Urtasun; Dorcus Fulton; Peter H.S. Geggie; Hilary Tanasichuk; Harvy Thomas; Paul J. Muller; Burnadette Curry; Bruce Mielke; Edward S. Johnson; Michael Feldstein

Various attempts have been made to improve the effectiveness of radiation in the treatment of cerebral malignant astrocytomas. A trend favoring multiple daily fractionated (MDF) radiation therapy over conventional single daily fractionated (CF) radiation therapy was identified in our previous study. In order to assess the effect of MDF with and without misonidazole, a province‐wide prospective randomized trial was initiated in January 1981. By March 1984, 124 patients with histologically verified grade III and IV astrocytomas were randomized to CF (5800 cGy/6 weeks/30 fractions) MDF (6141 cGy/4.5 weeks/69 fractions at 89 cGy every 3–4 hours, three times a day) and MDF in combination with misonidazole (1.25 g/m2 three times weekly for the first 3 weeks). Thirty‐eight patients were randomized to CF, 43 patients to MDF, and 43 patients to MDF and misonidazole. At the preliminary assessment in July 1984, the median survival time was 27 weeks for the CF group, 39 weeks for the MDF group and 49 weeks for MDF and misonidazole group. The 1‐year actuarial survival rate from surgery was 20% for CF group, 41% for MDF group, and 45% for MDF and misonidazole group. There is a statistically significant difference (P < 0.001) between the CF and MDF group. However, the addition of misonidazole does not significantly alter survival.


Journal of Neuro-oncology | 1992

Increasing radiation dose intensity using hyperfractionation in patients with malignant glioma

Dorcas Fulton; Raul C. Urtasun; I. Scott-Brown; Edward S. Johnson; Bruce Mielke; B. Curry; D. Huyser-Wierenga; J. Hanson; M. Feldstein

We attempted to show a dose effect relationship for radiation therapy by treating patients harbouring malignant glioma with increasing doses of radiation in a step-wise fashion. We postulated that no increase in delayed toxicity would be seen because we used hyperfractionation technique. Between January 1981 and December 1988 we treated 280 patients three times daily at 4 hour intervals. 100 patients received a total dose of 6141 cGy, 73 patients received 7120 cGy, and 107 patients received 8000 cGy. CCNU was given at the time of tumor progression following radiotherapy. Median time to tumor progression was 28 weeks for patients who received 6141 cGy, 27 weeks for patients who received 7120 cGy and 36 weeks for patients who received 8000 cGy. Median survival was 46 weeks for patients who received 6141 cGy, 38 weeks for patients who received 7120 cGy and 45 weeks for patients who received 8000 cGy. There was no statistically significant difference in either time to tumor progression or survival among the three treatment arms and no dose response effect was seen. There was no increase in delayed radiation toxicity when the total radiation dose was increased up to 8000 cGy.


Clinical Infectious Diseases | 2004

First Report of Schistosoma mekongi Infection with Brain Involvement

Stan Houston; Kinga Kowalewska-Grochowska; Sandeep Naik; John McKean; Edward S. Johnson; Ken Warren

We describe, to our knowledge, the first reported case of Schistosoma mekongi infection with brain involvement. S. mekongi is a distinct species most closely related to Schistosoma japonicum that is endemic in a defined area of the Mekong River in Laos and Cambodia and characteristically associated with hepatosplenic disease. The patient had an excellent response to praziquantel therapy but required repeated courses of corticosteroid therapy to suppress recrudescent neurological symptoms.


Journal of Neuroinflammation | 2013

Inflammasome induction in Rasmussen's encephalitis: cortical and associated white matter pathogenesis.

Vijay Ramaswamy; John G. Walsh; D. Barry Sinclair; Edward S. Johnson; Richard Tang-Wai; B. Matt Wheatley; William Branton; Ferdinand Maingat; Thomas Snyder; Donald W. Gross; Christopher Power

BackgroundRasmussen’s encephalitis (RE) is an inflammatory encephalopathy of unknown cause defined by seizures with progressive neurological disabilities. Herein, the pathogenesis of RE was investigated focusing on inflammasome activation in the brain.MethodsPatients with RE at the University of Alberta, Edmonton, AB, Canada, were identified and analyzed by neuroimaging, neuropsychological, molecular, and pathological tools. Primary human microglia, astrocytes, and neurons were examined using RT-PCR, enzyme-linked immunosorbent assay (ELISA), and western blotting.ResultsFour patients with RE were identified at the University of Alberta. Magnetic resonance imaging (MRI) disclosed increased signal intensities in cerebral white matter adjacent to cortical lesions of RE patients, accompanied by a decline in neurocognitive processing speed (P <0.05). CD3ϵ, HLA-DRA, and TNFα together with several inflammasome-associated genes (IL-1β, IL-18, NLRP1, NLRP3, and CASP1) showed increased transcript levels in RE brains compared to non-RE controls (n = 6; P <0.05). Cultured human microglia displayed expression of inflammasome-associated genes and responded to inflammasome activators by releasing IL-1β, which was inhibited by the caspase inhibitor, zVAD-fmk. Major histocompatibility complex (MHC) class II, IL-1β, caspase-1, and alanine/serine/cysteine (ASC) immunoreactivity were increased in RE brain tissues, especially in white matter myeloid cells, in conjunction with mononuclear cell infiltration and gliosis. Neuroinflammation in RE brains was present in both white matter and adjacent cortex with associated induction of inflammasome components, which was correlated with neuroimaging and neuropsychological deficits.ConclusionInflammasome activation likely contributes to the disease process underlying RE and offers a mechanistic target for future therapeutic interventions.


JAMA Neurology | 2010

Neuroinflammation and demyelination in multiple sclerosis after allogeneic hematopoietic stem cell transplantation.

Jian-Qiang Lu; Jeffrey T. Joseph; Richard A. Nash; Jan Storek; Anne M. Stevens; Luanne M. Metz; Arthur W. Clark; Edward S. Johnson; V. Wee Yong

OBJECTIVE To evaluate the effects of allogeneic hematopoietic stem cell transplantation (allo-HSCT) on the brains of persons with and without multiple sclerosis (MS) by means of postmortem histopathological examination. DESIGN Postmortem histopathology, case studies, and case-control studies. Patients Four patients with MS who died at a median of 4.5 months (range, 3-9 months) after allo-HSCT for a concomitant hematologic malignant neoplasm; 5 patients without MS who died at a median of 10.0 months (1-29 months) after allo-HSCT; and 5 control subjects without MS who did not undergo allo-HSCT. SETTING Referral centers. Intervention Allogeneic hematopoietic stem cell transplantation. MAIN OUTCOME MEASURES Morphological features and immunohistochemical features, including the quantitative measures of chronic inflammatory cells. RESULTS Demyelinating and inflammatory activities of MS persisted after allo-HSCT in all of the patients with MS. Active and chronic active MS lesions exhibited significantly higher numbers of CD3+ T cells and CD8+ cytotoxic T cells and significantly higher scores of CD68+ microglia/macrophages than did chronic inactive lesions or normal-appearing white matter. The normal-appearing brains of allo-HSCT recipients who did not have MS were found to have significantly higher numbers of CD3+ T cells and CD8+ cytotoxic T cells and higher scores of CD68+ microglia/macrophages compared with the controls; however, no demyelination was identified in these non-MS samples. CONCLUSION Allo-HSCT fails to halt the demyelination and inflammation of MS.


Journal of Child Neurology | 2011

An unusual presentation of copper metabolism disorder and a possible connection with Niemann-Pick type C.

Helly R. Goez; Francois Dominique Jacob; Robert D. Fealey; Marc C. Patterson; Vijay Ramaswamy; Rabin Persad; Edward S. Johnson; Jerome Y. Yager

Abnormal copper metabolism has been linked with neurological disorders, such as Wilson and Menkes disease. Another disorder causing symptoms similar to copper metabolism disorder is Niemann-Pick type C. However, a definite pathophysiological connection between Niemann-Pick type C and copper metabolism disorders has never been established. The authors present an adolescent with an unusual presentation of copper deficiency—dysarthria, ataxia, and vertical gaze paresis, without significant cognitive degeneration or pathological magnetic resonance imaging (MRI). The patient was found to carry 2 mutations in the NPC1 gene. A possible link, explaining how copper deficiency might induce the Niemann-Pick phenotype might involve overproduction of cholesterol and inhibition of acid sphingomyelinase. We suggest that copper metabolism disorders be included in the differential diagnosis for ataxia and dysarthria, even in cases with unusual presentations. Moreover, should the connection between copper and Niemann-Pick be validated, screening for copper metabolism disorders may be advisable in Niemann-Pick type C patients and vice-versa.


American Journal of Neuroradiology | 1986

Demonstration of a symptomatic intraventricular cyst using direct intraventricular metrizamide instillation

Rita Jeannette Marie Blom; Norbert Witt; Edward S. Johnson

A 30-year-old man presented with a “pressure” sensation in the left occipital and frontal regions. For the previous four months he suffered from rage attacks, brief losses of consciousness and occasional numbness of his right side.

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B. Curry

University of Calgary

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