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Lebwohl B, Ma C, Lagana SM, Pai RK, Baker KA, Zayadi A, Hogan M, Bouma G, Cellier C, Goldsmith JD, Lundin KEA, Pinto-Sanchez MI, Robert ME, Rubio-Tapia A, Sanders DS, Schaeffer DF, Semrad CE, Silvester JA, Verdú EF, Verma R, Wu TT, Feagan BG, Crowley E, Jairath V, Murray JA. Standardizing Randomized Controlled Trials in Celiac Disease: An International Multidisciplinary Appropriateness Study. Gastroenterology 2024; 166:88-102. [PMID: 37704112 DOI: 10.1053/j.gastro.2023.08.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/22/2023] [Accepted: 08/30/2023] [Indexed: 09/15/2023]
Abstract
BACKGROUND & AIMS There is a need to develop safe and effective pharmacologic options for the treatment of celiac disease (CeD); however, consensus on the appropriate design and configuration of randomized controlled trials (RCTs) in this population is lacking. METHODS A 2-round modified Research and Development/University of California Los Angeles Appropriateness Method study was conducted. Eighteen gastroenterologists (adult and pediatric) and gastrointestinal pathologists voted on statements pertaining to the configuration of CeD RCTs, inclusion and exclusion criteria, gluten challenge, and trial outcomes. Two RCT designs were considered, representing the following distinct clinical scenarios for which pharmacotherapy may be used: trials incorporating a gluten challenge to simulate exposure; and trials evaluating reversal of histologic changes, despite attempted adherence to a gluten-free diet. Each statement was rated as appropriate, uncertain, or inappropriate, using a 9-point Likert scale. RESULTS For trials evaluating prevention of relapse after gluten challenge, participants adherent to a gluten-free diet for 12 months or more with normal or near-normal-sized villi should be enrolled. Gluten challenge should be FODMAPS (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) free, and efficacy evaluated using histology with a secondary patient-reported outcome measure. For trials evaluating reversal of villus atrophy, the panel voted it appropriate to enroll participants with a baseline villus height to crypt depth ratio ≤2 and measure efficacy using a primary histologic end point. Guidance for measuring histologic, endoscopic, and patient-reported outcomes in adult and pediatric patients with CeD are provided, along with recommendations regarding the merits and limitations of different end points. CONCLUSIONS We developed standardized recommendations for clinical trial design, eligibility criteria, outcome measures, gluten challenge, and disease evaluations for RCTs in patients with CeD.
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Affiliation(s)
- Benjamin Lebwohl
- Celiac Disease Center, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York.
| | - Christopher Ma
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada; Alimentiv Inc, London, Ontario, Canada.
| | - Stephen M Lagana
- Department of Pathology and Cell Biology, Columbia University, New York, New York
| | - Rish K Pai
- Department of Pathology and Laboratory Medicine, Mayo Clinic Arizona, Scottsdale, Arizona
| | | | | | | | - Gerd Bouma
- Department of Gastroenterology and Hepatology, Amsterdam University Medical Center, Vrije Universiteit Amsterdam, Amsterdam Gastroenterology Endocrinology Metabolism Research Institute, Amsterdam, The Netherlands
| | - Christophe Cellier
- Department of Gastroenterology, University of Paris-Cité, Georges-Pompidou European Hospital, Assistance Publique des Hôpitaux de Paris, Paris, France
| | | | - Knut E A Lundin
- Norwegian Coeliac Disease Research Centre, University of Oslo Faculty of Medicine, Oslo, Norway; Department of Gastroenterology, Oslo University Hospital Rikshospitalet, Oslo, Norway
| | - Maria I Pinto-Sanchez
- Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Marie E Robert
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut
| | - Alberto Rubio-Tapia
- Celiac Disease Program, Division of Gastroenterology, Hepatology, and Nutrition, Digestive Disease and Surgery Institute, Cleveland Clinic, Cleveland, Ohio
| | - David S Sanders
- Academic Unit of Gastroenterology, Royal Hallamshire Hospital, Sheffield, United Kingdom
| | - David F Schaeffer
- Department of Pathology and Laboratory Medicine, Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - Carol E Semrad
- Department of Gastroenterology, University of Chicago, Chicago, Illinois
| | - Jocelyn A Silvester
- Harvard Celiac Research Program, Harvard Medical School, Boston, Massachusetts; Division of Gastroenterology, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts; Celiac Disease Center, Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Elena F Verdú
- Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Ritu Verma
- Department of Pediatrics, Section of Gastroenterology, Hepatology and Nutrition, The University of Chicago, Chicago, Illinois
| | - Tsung-Teh Wu
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Brian G Feagan
- Alimentiv Inc, London, Ontario, Canada; Division of Gastroenterology, Department of Medicine, Western University, London, Ontario, Canada; Department of Epidemiology and Biostatistics, Western University, London, Ontario, Canada
| | - Eileen Crowley
- Alimentiv Inc, London, Ontario, Canada; Division of Pediatric Gastroenterology, Department of Pediatrics, Children's Hospital Western Ontario, London Health Sciences Centre, Western University, London, Ontario, Canada
| | - Vipul Jairath
- Alimentiv Inc, London, Ontario, Canada; Division of Gastroenterology, Department of Medicine, Western University, London, Ontario, Canada; Department of Epidemiology and Biostatistics, Western University, London, Ontario, Canada
| | - Joseph A Murray
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota
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Baker KA, Stabile VJ, Mondloch CJ. Stable individual differences in unfamiliar face identification: Evidence from simultaneous and sequential matching tasks. Cognition 2023; 232:105333. [PMID: 36508992 DOI: 10.1016/j.cognition.2022.105333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 11/14/2022] [Accepted: 11/19/2022] [Indexed: 12/14/2022]
Abstract
Matching identity in images of unfamiliar faces is difficult: Images of the same person can look different and images of different people can look similar. Recent studies have capitalized on individual differences in the ability to distinguish match (same ID) vs. mismatch (different IDs) face pairs to inform models of face recognition. We addressed two significant gaps in the literature by examining the stability of individual differences in both sensitivity to identity and response bias. In Study 1, 210 participants completed a battery of four tasks in each of two sessions separated by one week. Tasks varied in protocol (same/different, lineup, sorting) and stimulus characteristics (low vs. high within-person variability in appearance). In Study 2, 148 participants completed a battery of three tasks in a single session. Stimuli were presented simultaneously on some trials and sequentially on others, introducing short-term memory demands. Principal components analysis revealed two components that were stable across time and tasks: sensitivity to identity and bias. Analyses of response times suggest that individual differences in bias reflect decision-making processes. We discuss the implications of our findings in applied settings and for models of face recognition.
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Maratt JK, Siegel CA, Barkun AN, Bouhnik Y, Bressler B, Calderwood AH, East JE, Fischer M, Grossmann J, Korzenik JR, Menees SB, Panes J, Rex DK, Sey MSL, Allio MK, Baker KA, Guizzetti L, Remillard J, Sedano R, Feagan BG, Ma C, Jairath V. An Expert Consensus to Standardize Assessment of Bowel Cleansing for Clinical Trials of Bowel Preparations for Crohn's Disease. Dig Dis Sci 2022; 68:1718-1727. [PMID: 36436154 DOI: 10.1007/s10620-022-07775-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 11/14/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Despite regular need for colonoscopy in patients with Crohn's disease (CD), the efficacy and tolerability of bowel preparation (BP) agents is rarely assessed in this population. Assessing BP quality with existing scales may be challenging in CD due to presence of inflammation, bowel resection, and strictures. AIMS To provide recommendations for assessing BP quality in clinical trials for CD using a modified Research and Development/University of California, Los Angeles appropriateness process. METHODS Based on systematic reviews and a literature search, 110 statements relating to BP quality assessment in CD were developed. A panel of 15 gastroenterologists rated the statements as appropriate, uncertain, or inappropriate using a 9-point Likert scale. RESULTS Panelists considered it appropriate that central readers, either alone or with local assessment, score BP quality in clinical trials. Central readers should be trained on scoring BP quality and local endoscopists on performing high-quality video recording. Both endoscope insertion and withdrawal phases should be reviewed to score BP quality in each colonic segment and segments should align with endoscopic disease activity indices. The Harefield Cleansing Scale and the Boston Bowel Preparation Scale were considered appropriate. The final score should be calculated as the average of all visualized segments. Both total and worst segment scores should also be assessed. CONCLUSIONS We developed a framework for assessing BP quality in patients with CD based on expert feedback. This framework could support the development or refinement of BP quality scales and the integration of BP quality assessment in future CD studies.
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Affiliation(s)
- Jennifer K Maratt
- Division of Gastroenterology and Hepatology, Indiana University School of Medicine, 340 W 10Th St, Indianapolis, IN, 46202, USA.,Richard L. Roudebush Veterans Affairs Medical Center, 1481 W 10Th St, Indianapolis, IN, 46202, USA.,Regenstrief Institute, Inc, 1101 W 10Th St, Indianapolis, IN, 46202, USA
| | - Corey A Siegel
- Department of Medicine, Section of Gastroenterology and Hepatology, Dartmouth-Hitchcock Medical Center, 1 Medical Center Dr, Lebanon, NH, 03766, USA
| | - Alan N Barkun
- Division of Gastroenterology, McGill University and McGill University Health Centre, 1001 Decarie Blvd, Montreal, QC, H4A 3J1, Canada
| | - Yoram Bouhnik
- Gastroenterology and Nutrition Support Department, Department of Gastroenterology, Beaujon Hospital, 100 Bd du Général Leclerc, 92110, Clichy, France
| | - Brian Bressler
- Division of Gastroenterology, Department of Medicine, St Paul's Hospital, University of British Columbia, 1081 Burrard St, Vancouver, BC, V6Z 1Y6, Canada
| | - Audrey H Calderwood
- Department of Medicine, Section of Gastroenterology and Hepatology, Dartmouth-Hitchcock Medical Center, 1 Medical Center Dr, Lebanon, NH, 03766, USA.,The Geisel School of Medicine at Dartmouth, 1 Rope Ferry Rd, Hanover, NH, 03755, USA.,Dartmouth Institute of Health Policy and Clinical Practice, 1 Medical Center Dr, Lebanon, NH, 03766, USA
| | - James E East
- Translational Gastroenterology Unit, John Radcliffe Hospital, Headley Way, Headington, Oxford, OX3 9DU, UK.,Division of Gastroenterology and Hepatology, Mayo Clinic Healthcare London, 15 Portland Pl, London, W1B 1PT, UK
| | - Monika Fischer
- Division of Gastroenterology and Hepatology, Indiana University School of Medicine, 340 W 10Th St, Indianapolis, IN, 46202, USA
| | - Johannes Grossmann
- Department of Internal Medicine I, Bethesda Hospital, Glindersweg 80, 21029, Hamburg, Germany.,Johanniter GmbH, Ludwig-Weber-Straße 15, 41061, Mönchengladbach, Germany
| | - Joshua R Korzenik
- Division of Gastroenterology, Hepatology and Endoscopy, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA.,Harvard Medical School, 25 Shattuck St, Boston, MA, 02115, USA
| | - Stacy B Menees
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Michigan, 500 S State St, Ann Arbor, MI, 48109, USA.,Veterans Affairs Ann Arbor Healthcare System, 2215 Fuller Rd, Ann Arbor, MI, 48105, USA
| | - Julian Panes
- Inflammatory Bowel Disease Unit, Department of Gastroenterology, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigaciones Biomédicas en Red en Enfermedades Hepáticas y Digestivas (CIBEREHD), Hospital Clínic de Barcelona, C. de Villarroel, 170, 08036, Barcelona, Spain
| | - Douglas K Rex
- Division of Gastroenterology and Hepatology, Indiana University School of Medicine, 340 W 10Th St, Indianapolis, IN, 46202, USA
| | - Michael S L Sey
- Division of Gastroenterology, Department of Medicine, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada
| | - Michael K Allio
- ColonaryConcepts LLC, 103 San Marco Dr, Palm Beach Gardens, FL, 33418, USA
| | - K Adam Baker
- Alimentiv Inc, 100 Dundas St Suite 200, London, ON, N6A 5B6, Canada
| | | | - Julie Remillard
- Alimentiv Inc, 100 Dundas St Suite 200, London, ON, N6A 5B6, Canada
| | - Rocio Sedano
- Division of Gastroenterology, Department of Medicine, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada.,Alimentiv Inc, 100 Dundas St Suite 200, London, ON, N6A 5B6, Canada
| | - Brian G Feagan
- Division of Gastroenterology, Department of Medicine, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada.,Alimentiv Inc, 100 Dundas St Suite 200, London, ON, N6A 5B6, Canada.,Department of Epidemiology and Biostatistics, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada
| | - Christopher Ma
- Alimentiv Inc, 100 Dundas St Suite 200, London, ON, N6A 5B6, Canada.,Division of Gastroenterology and Hepatology, Departments of Medicine and Community Health Sciences, University of Calgary, 2500 University Dr NW, Calgary, AB, T2N 1N4, Canada
| | - Vipul Jairath
- Division of Gastroenterology, Department of Medicine, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada. .,Alimentiv Inc, 100 Dundas St Suite 200, London, ON, N6A 5B6, Canada. .,Department of Epidemiology and Biostatistics, Western University, 1151 Richmond St, London, ON, N6A 3K7, Canada. .,Department of Medicine, Western University, 399 Windermere Road, London, ON, N6A 5A5, Canada.
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Jairath V, Guizzetti L, Baker KA, Williamson LA, Sedano R, Thompson H, Ma C. Impact of COVID-19 on Inflammatory Bowel Disease Clinical Trial Recruitment: A Global Survey of Principal Investigators. Inflamm Bowel Dis 2021; 27:e98. [PMID: 33988238 PMCID: PMC8244581 DOI: 10.1093/ibd/izab111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Affiliation(s)
- Vipul Jairath
- Alimentiv Inc. (formerly Robarts Clinical Trials,
Inc.), London, Ontario, Canada
- Department of Medicine, Division of Gastroenterology,
Western University, London, Ontario,
Canada
- Department of Epidemiology and Biostatistics, Western
University, London, Ontario, Canada
- Address correspondence to: Vipul Jairath, MBChB, DPhil, Western
University, London, Ontario, Canada ()
| | - Leonardo Guizzetti
- Alimentiv Inc. (formerly Robarts Clinical Trials,
Inc.), London, Ontario, Canada
| | - K Adam Baker
- Alimentiv Inc. (formerly Robarts Clinical Trials,
Inc.), London, Ontario, Canada
| | - Lee Anne Williamson
- Alimentiv Inc. (formerly Robarts Clinical Trials,
Inc.), London, Ontario, Canada
| | - Rocio Sedano
- Alimentiv Inc. (formerly Robarts Clinical Trials,
Inc.), London, Ontario, Canada
- Department of Medicine, Division of Gastroenterology,
Western University, London, Ontario,
Canada
| | - Hershell Thompson
- Alimentiv Inc. (formerly Robarts Clinical Trials,
Inc.), London, Ontario, Canada
| | - Christopher Ma
- Alimentiv Inc. (formerly Robarts Clinical Trials,
Inc.), London, Ontario, Canada
- Division of Gastroenterology and Hepatology, Departments
of Medicine and Community Health Sciences, Cumming School of Medicine,
University of Calgary, Calgary, Alberta,
Canada
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5
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Baker KA, Mondloch CJ. Two Sides of Face Learning: Improving Between-Identity Discrimination While Tolerating More Within-Person Variability in Appearance. Perception 2019; 48:1124-1145. [PMID: 31483735 DOI: 10.1177/0301006619867862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Two photos of an unfamiliar face are often perceived as belonging to different people—an error that disappears when a face is familiar. Face learning has been characterized as increased tolerance of within-person variability in appearance and is facilitated by exposure to such variability (e.g., differences in expression, lighting, and aesthetics). We hypothesized that increased tolerance of variability in appearance might lead to reduced discrimination and that misidentifications would be reduced if a face was learned in the context of a similar-looking identity. After validating our stimuli (Experiments 1a and 1b), we conducted three experiments investigating face learning. In two of these, participants learned three faces (Experiment 2: 15 images/identity and Experiment 3: 5 images/identity), two of which were similar. In a recognition task, misidentifications did not change as a function of similarity, although participants recognized more images of the target in Experiment 2 (i.e., after learning 15 images). In Experiment 4, participants learned one identity and the number of images studied varied across groups. Recognition of new images increased with the number of images studied, with no changes in false alarms; sensitivity (A′) marginally increased. The results suggest that recognition and discrimination reflect separable processes with minimal influence of between-person similarity on discrimination.
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Affiliation(s)
- K A Baker
- Department of Psychology, Brock University, St. Catharines, Ontario, Canada
| | - C J Mondloch
- Department of Psychology, Brock University, St. Catharines, Ontario, Canada
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Gulliver WP, MacDonald D, Gladney N, Alaghehbandan R, Rahman P, Baker KA. Long-Term Prognosis and Comorbidities Associated with Psoriasis in the Newfoundland and Labrador Founder Population. J Cutan Med Surg 2011; 15:37-47. [DOI: 10.2310/7750.2010.10013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Background: Psoriasis is a common chronic immune-mediated inflammatory disorder of the skin with several associated comorbidities. Objective: To assess the prevalence of comorbidities in a cohort of psoriasis patients within the Canadian province of Newfoundland and Labrador (NL). Methods: This cross-sectional observational study investigated hospital-coded comorbidities associated with psoriasis in comparison to the general NL hospitalized population. Results: Patients died significantly younger than the general population, with patients having an earlier disease onset (≤ 25 years) dying at a younger age than those with a later onset (> 25 years; 59.3 vs 71.2; p = .001). Patients were hospitalized more frequently for several system disorders than the general population, and a potential association was observed between prognostic factors such as age at onset, disease severity, and HLA-Cw6 genotype and certain comorbid conditions. Conclusion: This study supports an association between psoriasis and other conditions, such as circulatory and endocrine diseases.
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Affiliation(s)
- Wayne P. Gulliver
- From the Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland; NewLab Life Sciences, Incorporated; and Research and Evaluation Department, Newfoundland and Labrador Centre for Health Information, St. John's, NL
| | - Don MacDonald
- From the Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland; NewLab Life Sciences, Incorporated; and Research and Evaluation Department, Newfoundland and Labrador Centre for Health Information, St. John's, NL
| | - Neil Gladney
- From the Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland; NewLab Life Sciences, Incorporated; and Research and Evaluation Department, Newfoundland and Labrador Centre for Health Information, St. John's, NL
| | - Reza Alaghehbandan
- From the Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland; NewLab Life Sciences, Incorporated; and Research and Evaluation Department, Newfoundland and Labrador Centre for Health Information, St. John's, NL
| | - Proton Rahman
- From the Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland; NewLab Life Sciences, Incorporated; and Research and Evaluation Department, Newfoundland and Labrador Centre for Health Information, St. John's, NL
| | - K. Adam Baker
- From the Discipline of Medicine, Faculty of Medicine, Memorial University of Newfoundland; NewLab Life Sciences, Incorporated; and Research and Evaluation Department, Newfoundland and Labrador Centre for Health Information, St. John's, NL
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Rajasekharan S, Baker KA, Horn KE, Jarjour AA, Antel JP, Kennedy TE. Netrin 1 and Dcc regulate oligodendrocyte process branching and membrane extension via Fyn and RhoA. Development 2009; 136:415-26. [PMID: 19141671 DOI: 10.1242/dev.018234] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The molecular mechanisms underlying the elaboration of branched processes during the later stages of oligodendrocyte maturation are not well understood. Here we describe a novel role for the chemotropic guidance cue netrin 1 and its receptor deleted in colorectal carcinoma (Dcc) in the remodeling of oligodendrocyte processes. Postmigratory, premyelinating oligodendrocytes express Dcc but not netrin 1, whereas mature myelinating oligodendrocytes express both. We demonstrate that netrin 1 promotes process extension by premyelinating oligodendrocytes in vitro and in vivo. Addition of netrin 1 to mature oligodendrocytes in vitro evoked a Dcc-dependent increase in process branching. Furthermore, expression of netrin 1 and Dcc by mature oligodendrocytes was required for the elaboration of myelin-like membrane sheets. Maturation of oligodendrocyte processes requires intracellular signaling mechanisms involving Fyn, focal adhesion kinase (FAK), neuronal Wiscott-Aldrich syndrome protein (N-WASP) and RhoA; however, the extracellular cues upstream of these proteins in oligodendrocytes are poorly defined. We identify a requirement for Src family kinase activity downstream of netrin-1-dependent process extension and branching. Using oligodendrocytes derived from Fyn knockout mice, we demonstrate that Fyn is essential for netrin-1-induced increases in process branching. Netrin 1 binding to Dcc on mature oligodendrocytes recruits Fyn to a complex with the Dcc intracellular domain that includes FAK and N-WASP, resulting in the inhibition of RhoA and inducing process remodeling. These findings support a novel role for netrin 1 in promoting oligodendrocyte process branching and myelin-like membrane sheet formation. These essential steps in oligodendroglial maturation facilitate the detection of target axons, a key step towards myelination.
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Affiliation(s)
- Sathyanath Rajasekharan
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H3A 2B4, Canada
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Baker KA, Nakashima S, Hagg T. Dorsal column sensory axons lack TrkC and are not rescued by local neurotrophin-3 infusions following spinal cord contusion in adult rats. Exp Neurol 2007; 205:82-91. [PMID: 17316612 DOI: 10.1016/j.expneurol.2007.01.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2006] [Revised: 12/14/2006] [Accepted: 01/19/2007] [Indexed: 11/17/2022]
Abstract
By reducing the progressive degeneration and disconnection of axons following spinal cord injury the functional outcome should improve. After direct transection of dorsal column sensory axons, neurotrophin-3 (NT-3) treatment can reduce degeneration and promote regeneration of the proximal stumps. Here, we tested in adult rats whether NT-3 infusion at the site of a moderate T9 spinal cord contusion would rescue sensory connections to the gracile nucleus in the medulla. Sensory projections were anterogradely traced bilaterally with injections of cholera toxin B (CTB) into the sciatic nerve 3 days before analysis. Seven days after the contusion plus intrathecal (subarachnoid) vehicle infusion as a control, the CTB-positive innervation of the gracile nucleus was reduced to approximately 25% of sham-operated rats. Intrathecal infusion of 10 microg/day of NT-3 did not affect this reduced innervation. To ensure good tissue penetration and high concentrations of NT-3 early after the injury, other rats received intraparenchymal infusions of vehicle or NT-3 near the injury site starting 2 days before until 7 days after the injury. This NT-3 treatment also did not affect the reduced innervation. This suggests that local NT-3 treatments cannot protect sensory axons from secondary degeneration after a contusive spinal cord injury. These results are likely because TrkC is not present in axons of the dorsal columns or gracile nucleus, or in other dorsal column cell types, even after the contusion. Together with published results, our data suggest that NT-3 is a peripherally--but not centrally--derived neurotrophic factor for sensory neurons.
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Affiliation(s)
- K Adam Baker
- Kentucky Spinal Cord Injury Research Center, Department of Neurological Surgery, MDR Building, Room 616, University of Louisville, Louisville, KY 40292, USA
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9
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Baker KA, Hagg T. Developmental and injury-induced expression of alpha1beta1 and alpha6beta1 integrins in the rat spinal cord. Brain Res 2006; 1130:54-66. [PMID: 17161391 PMCID: PMC1794000 DOI: 10.1016/j.brainres.2006.10.072] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Revised: 10/20/2006] [Accepted: 10/26/2006] [Indexed: 12/27/2022]
Abstract
Loss and damage to blood vessels are thought to contribute to secondary tissue loss after spinal cord injury. Integrins might be therapeutic targets to protect the vasculature and/or promote angiogenesis, as their activation can promote tubule formation and survival of endothelial cells in vitro. Here, we show that immunostaining with an antibody against the alpha1beta1 integrin heterodimer is present only in blood vessels from postnatal day 1 (P1) through adulthood in Sprague-Dawley rats. After a spinal cord contusion at T9 in adults, the area of alpha1beta1 integrin positive blood vessels increases within 11 mm from the injury site at 3 days post-injury and remains prominent within the injured core only at 7 days. Staining for the alpha6beta1 integrin heterodimer increases in blood vessels between P10 and adulthood and is present in preganglionic neurons of the intermediolateral cell column (IML) at all ages. The alpha6beta1 integrin is also expressed by motor neurons postnatally, and oligodendrocyte precursors (OPCs), as previously reported. After the contusion, the area of alpha6beta1-stained blood vessels is increased at 3 days and most prominently, 1 mm from the injury site, followed by a significant reduction at 7 days, when alpha6beta1 integrin staining is most prominent around the injured core. Staining is also present in a subset of microglia and/or macrophages. These results raise the possibility that alpha1beta1 and alpha6beta1 integrins in blood vessels might be targeted to reduce blood vessel loss and promote angiogenesis, which may promote tissue sparing after spinal cord injury.
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Affiliation(s)
- K Adam Baker
- Kentucky Spinal Cord Injury Research Center, Department of Neurological Surgery, MDR Building, Room 616, University of Louisville, Louisville, KY, USA
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10
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Baker KA, Moore SW, Jarjour AA, Kennedy TE. When a diffusible axon guidance cue stops diffusing: roles for netrins in adhesion and morphogenesis. Curr Opin Neurobiol 2006; 16:529-34. [PMID: 16935486 DOI: 10.1016/j.conb.2006.08.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Accepted: 08/17/2006] [Indexed: 10/24/2022]
Abstract
Netrins are a small family of secreted proteins that are best known for their role as secreted long-range chemotropic guidance cues. Extracellular gradients of netrin protein, established by diffusion, are thought to direct cell and axon migration during neural development. In addition to this long-range role, recent findings provide increasing support for short-range functions, in which secreted netrin protein remains closely associated with its cellular source. Emerging evidence for short-range actions of netrins suggests that they contribute to tissue morphogenesis by regulating cell-cell and cell-matrix adhesion.
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Affiliation(s)
- K Adam Baker
- Centre for Neuronal Survival, Montréal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, H3A 2B4, Canada
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Yang P, Baker KA, Hagg T. The ADAMs family: coordinators of nervous system development, plasticity and repair. Prog Neurobiol 2006; 79:73-94. [PMID: 16824663 DOI: 10.1016/j.pneurobio.2006.05.001] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Revised: 05/18/2006] [Accepted: 05/23/2006] [Indexed: 10/24/2022]
Abstract
A disintegrin and metalloprotease (ADAM) transmembrane proteins have metalloprotease, integrin-binding, intracellular signaling and cell adhesion activities. In contrast to other metalloproteases, ADAMs are particularly important for cleavage-dependent activation of proteins such as Notch, amyloid precursor protein (APP) and transforming growth factor alpha (TGFalpha), and can bind integrins. Not surprisingly, ADAMs have been shown or suggested to play important roles in the development of the nervous system, where they regulate proliferation, migration, differentiation and survival of various cells, as well as axonal growth and myelination. On the eleventh anniversary of the naming of this family of proteins, the relatively unknown ADAMs are emerging as potential therapeutic targets for neural repair. For example, over-expression of ADAM10, one of the alpha-secretases for APP, can prevent amyloid formation and hippocampal defects in an Alzheimer mouse model. Another example of this potential neural repair role is the finding that ADAM21 is uniquely associated with neurogenesis and growing axons of the adult brain. This comprehensive review will discuss the growing literature about the roles of ADAMs in the developing and adult nervous system, and their potential roles in neurological disorders. Most excitingly, the expanding understanding of their normal roles suggests that they can be manipulated to promote neural repair in the degenerating and injured adult nervous system.
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Affiliation(s)
- Peng Yang
- Kentucky Spinal Cord Injury Research Center, Department of Neurological Surgery, University of Louisville, Louisville, KY 40292, USA
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Yang P, Baker KA, Hagg T. A disintegrin and metalloprotease 21 (ADAM21) is associated with neurogenesis and axonal growth in developing and adult rodent CNS. J Comp Neurol 2005; 490:163-79. [PMID: 16052496 DOI: 10.1002/cne.20659] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We have reported that alpha6beta1 integrin regulates the directed migration of neuroblasts from the adult rodent subventricular zone (SVZ) through the rostral migratory stream (RMS). ADAM (a disintegrin and metalloprotease) proteins bind integrins. Here, we show that ADAM21, but not ADAM2, -3, -9, -10, -12, -15, or -17, is expressed in adult rats and mice by ependyma and SVZ cells with long basal processes, and in radial glia at early postnatal times. ADAM21-positive processes projected into the RMS, contacted blood vessels, and were present within the RMS intermingled with neuroblasts up to where neuroblasts start their radial migration and differentiation in the olfactory bulb. Tissue inhibitors of metalloproteases (TIMPs) 1, 2, and 3 are present in the ependymal layer but not in the SVZ and RMS. Thus, ADAM21 could regulate neurogenesis and guide neuroblast migration through cleavage-dependent activation of proteins and integrin binding. ADAM21 is also present in growing axonal tracts during postnatal development and in growing primary olfactory axons in adults. In the olfactory nerve layer, ADAM21 often, but not always, colocalizes with OMP, a marker of mature olfactory neurons, but is not colocalized with the immature marker betaIII-tubulin. This suggests that ADAM21 is involved in the final axonal outgrowth phase and/or synapse formation. TIMP3 is present in periglomerular neurons, where it could restrict ADAM21-mediated axonal growth to the glomeruli. ADAM21's unique disintegrin and metalloprotease sequences and its restricted expression suggest that it might be a good target for influencing neurogenesis and neuronal plasticity.
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Affiliation(s)
- Peng Yang
- Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, 511 S. Floyd Street, Louisville, KY 40292, USA
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Baker KA, Hagg T. An adult rat spinal cord contusion model of sensory axon degeneration: the estrus cycle or a preconditioning lesion do not affect outcome. J Neurotrauma 2005; 22:415-28. [PMID: 15853460 DOI: 10.1089/neu.2005.22.415] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A therapeutic strategy for acute spinal cord injury would be to reduce the progressive degeneration and disconnection of axons from their targets. Here, we describe a model to evaluate degeneration of the ascending sensory projections to the nuclei in the medulla following graded spinal cord contusions in adult female Sprague-Dawley rats. Cholera toxin B (CTB) labeling from the sciatic nerve of naive rats revealed effective labeling of the terminal fibers in the gracile nucleus at 3 days post-injection and a subpopulation of rapidly transporting fibers after 1 day. Seven days after contusions using the Infinite Horizon impactor the area of CTB-labeled terminal fibers had a negative correlation with increasing impact force. Moderate spinal contusions of around 150 kilodyne (kdyn or 0.15 x 10(-3) newton) caused a reduction to 40% in the fiber area which will enable the identification of protective as well as detrimental drugs and post-injury mechanisms. A preconditioning injury of the sciatic nerve reportedly can enhance growth of sensory axons but did not affect the terminal fiber area in the gracile nucleus. Estrogen and progesterone are protective in various systems and could therefore influence experimental outcomes when using females. However, the phase of the estrus cycle at the time of contusion or during the post-injury time did not affect the outcome of the contusion, indicating that female rats may be used without consideration of the estrus cycle. This model can readily be used to evaluate pharmacological agents for protection of sensory axons and pathophysiological mechanisms of their degeneration.
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Affiliation(s)
- K Adam Baker
- Departments of Neurological Surgery, Anatomical Sciences and Neurobiology, Kentucky Spinal Cord Injury Research Center, University of Louisville, 511 S. Floyd Street, Louisville, KY 40292, USA
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Abstract
Terminally differentiated neurons derived from a human teratocarcinoma cell line (NT2N or hNT neurons) are promising as a cell source for transplantation, as they have been shown to be safe for transplantation in humans. We have shown previously that hNT neurons can express a catecholaminergic phenotype in a rat Parkinson model. In this study, we investigated the long-term survival and ability of hNT neurons to express tyrosine hydroxylase and reconstruct the dopamine-denervated nigrostriatal pathway. Hemiparkinsonian rats received grafts of 400,000 viable hNT neurons into each of the denervated striatum and substantia nigra. Robust hNT grafts were detected up to 24 weeks posttransplantation, although few cells expressed tyrosine hydroxylase. Many hNT fibers were often associated with ipsilateral and contralateral white matter tracts--corpus callosum, rostral migratory stream, optic tract, and external capsule. Fewer fibers were associated with the superior cerebellar peduncle, medial lemniscus, and nigrostriatal pathway. Axons also projected into the frontal cortex and extended parallel to the surface of the brain in the superficial cortical layers. These pathways were seen in all grafted animals, suggesting that specific guidance cues exist in the adult brain governing hNT fiber outgrowth. Injured adult axons and transplanted embryonic neuronal axons rarely extend for such distances in the adult nervous system. We propose that elucidating the factors promoting and guiding hNT axonal outgrowth could provide important clues to enhancing regeneration and target reinnervation in the adult brain, two factors of critical importance for cell restoration strategies aimed at brain repair.
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Affiliation(s)
- K Adam Baker
- Neural Transplantation Laboratory, Department of Anatomy, Dalhousie University, Halifax, Nova Scotia, Canada
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Hagg T, Baker KA, Emsley JG, Tetzlaff W. Prolonged local neurotrophin-3 infusion reduces ipsilateral collateral sprouting of spared corticospinal axons in adult rats. Neuroscience 2005; 130:875-87. [PMID: 15652986 DOI: 10.1016/j.neuroscience.2004.10.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2004] [Indexed: 01/24/2023]
Abstract
The corticospinal tract is widely used to study regeneration and is essential for voluntary movements in humans. In young rats, corticospinal axons on the uninjured side sprout and grow into the denervated side. Neurotrophin-3 (NT-3) induces such crossed collateral sprouting in adults. We investigated whether local intraspinal NT-3 infusions would promote collateral sprouting of spared corticospinal terminals from within a partially denervated side, as this would be more appropriate for enhancing function of unilateral and specific movements. Adult rats received a partial bilateral transection of the pyramids, leaving approximately 40% of each tract intact. Vehicle or vehicle plus NT-3 (3 or 10 microg/day) was infused for 14 days into the left side of the cervical (C5/6) or lumbar (L2) cord. The corticospinal processes on the left side were anterogradely traced with cholera toxin B (CTB; which labeled gray matter processes more robustly than biotinylated dextran amine) injected into the front or hind limb area of the right sensorimotor cortex, respectively, 3 days before analysis. Unexpectedly, approximately 40% fewer CTB-labeled corticospinal processes were detectable in the cervical or lumbar gray matter of NT-3-treated rats than in vehicle-infused ones. Vehicle-infused injured rats had more corticospinal processes in the center of the cord than normal rats, evidence for lesion-induced collateral sprouting. NT-3 caused sprouting of local calcitonin gene-related peptide-positive fibers. These results suggest that NT-3 reduces collateral sprouting of spared corticospinal axons from within the denervated regions, possibly because of the injury environment or by increasing sprouting of local afferents. They identify an unexpected context-dependent outgrowth inhibitory effect of NT-3.
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Affiliation(s)
- T Hagg
- Department of Neurological Surgery, Kentucky Spinal Cord Injury Research Center, 511 South Floyd Street, MDR Room 616, University of Louisville, Louisville, KY 40292, USA.
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Baker SA, Baker KA, Hagg T. D3 dopamine receptors do not regulate neurogenesis in the subventricular zone of adult mice. Neurobiol Dis 2005; 18:523-7. [PMID: 15755679 DOI: 10.1016/j.nbd.2005.01.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2004] [Revised: 12/22/2004] [Accepted: 01/04/2005] [Indexed: 10/25/2022] Open
Abstract
Testing the effects of drugs that stimulate endogenous neurogenesis in different species is important for the development of neural repair strategies in humans. We have previously shown in adult rats that a 14-day intracerebroventricular infusion of the D3 preferential agonist 7-hydroxydipropyl-amino-tetraline (7-OH-DPAT) increases BrdU labeling of neural precursors in the subventricular zone of the anterior lateral ventricle (SVZ). Here, we show that such a treatment failed to affect neurogenesis in C57Bl/6 and FVB mice, even at a high dose or when infused into the neostriatum. We confirmed that such a treatment was effective in adult rats. Moreover, D3 receptor inhibition or genetic knockout failed to affect the neurogenesis in mice. These results raise the possibilities that neurogenesis is not regulated by D3 receptors in all species and, therefore, that D3 agonists like pramipexole may not be useful to harness endogenous neurogenesis in cell replacement strategies for Parkinson's disease.
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Affiliation(s)
- Sarah A Baker
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY 40292, USA
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Abstract
An understanding of the regulators of neurogenesis in the normal and diseased brain is necessary in order to recruit endogenously produced neural precursors for cell replacement in neurodegenerative disorders such as Parkinson's disease. The location of dopaminergic projections from the midbrain to the neostriatum and nucleus accumbens overlaps with the most active region of neurogenesis in the adult brain, the subventricular zone of the anterior lateral ventricle. This suggests that dopamine may contribute to regulation of the subventricular niche of adult neurogenesis. Here, we show in adult mice that destruction of the dopaminergic neurons in the substantia nigra and ventral tegmental area in a 6-hydroxydopamine model of Parkinson's disease reduced the number of proliferating neural precursors in the subventricular zone of the anterior lateral ventricle by approximately 40%. The effect on neural precursor proliferation correlated with the extent of dopaminergic denervation in the neighboring neostriatum. This identifies dopamine as one of the few known endogenous regulators of adult neurogenesis with implications for the potential use of endogenous neural precursors in cell replacement strategies for Parkinson's disease.
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Affiliation(s)
- Sarah A Baker
- Kentucky Spinal Cord Injury Research Center, University of Louisville, 511 S Floyd Street, MDR Room 616, Louisville, KY 40292, USA
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Baker KA, Purdy MB, Sadi D, Mukhida K, Mendez I. A sequential intrastriatal dopaminergic graft strategy in the rodent model for Parkinson's disease: implications for graft survival and targeting. Cell Transplant 2003; 11:185-93. [PMID: 12075984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
Optimal placement of intrastriatal dopaminergic grafts is likely crucial to optimize clinical recovery in Parkinson's disease (PD). The target sites of dopaminergic grafts vary among clinical trials and may partially explain the variable results in clinical efficacy reported thus far. In this study we hypothesized that a subsequent dopaminergic graft may promote functional recovery following a suboptimal initial graft. To test this hypothesis, rats with unilateral 6-hydroxydopamine lesions of the right nigrostriatal pathway were randomly divided into three groups. The first group received 900,000 fetal nigral cells in the medial striatum only (n = 6). The second group received 900,000 cells in both the medial and lateral striatum simultaneously (1.8 million total; n = 8). The final group received a second graft of 900,000 cells in the lateral striatum 6 weeks following initial transplantation of a medial graft (n = 6). Amphetamine-induced circling behavior was significantly reduced in both simultaneous and sequential graft groups at 9 and 12 weeks following transplantation of the initial graft. However, no recovery was noted in the single medial graft group at those time points. Furthermore, increased survival of dopaminergic cells was observed in the lateral graft of sequentially grafted animals compared with the medial graft. We conclude that a well-positioned subsequent graft can restore function in animals with a suboptimal initial graft and that the initial graft may improve survival of the second graft. These results are further discussed in relation to their important clinical implication for neural transplantation in PD.
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Affiliation(s)
- K A Baker
- Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada
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Alemdar AY, Baker KA, Sadi D, McAlister VC, Mendez I. Liposomal tacrolimus administered systemically and within the donor cell suspension improves xenograft survival in hemiparkinsonian rats. Exp Neurol 2001; 172:416-24. [PMID: 11716565 DOI: 10.1006/exnr.2001.7801] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The most widely used immunosuppressant in neural transplantation is cyclosporine- A (CsA). However, CsA has significant toxic effects when administered systemically. Tacrolimus (FK506), is a more potent immunosuppressant than CsA and can be prepared in lipid micelles (LTAC). This liposomal preparation allows for the administration of tacrolimus to the site of transplantation, possibly reducing the systemic side effects of immunosuppression. In this study we investigated the ability of LTAC to promote graft survival in hemiparkinsonian rats implanted with fetal mouse xenografts when LTAC is administered systemically to the host, when added to the donor cell suspension, or in combination. Rats with unilateral 6-hydroxydopamine lesions were transplanted with 800,000 fetal mouse ventral mesencephalic (VM) cells and were randomly divided into four groups. Group 1 was not immunosuppressed; Group 2 received daily systemic injections of LTAC; Group 3 received LTAC within the cell suspensions of mouse VM cells; and Group 4 received LTAC in the cell suspensions along with daily systemic administration of LTAC. Transplanted rats were assessed for rotational behavior 3 and 6 weeks posttransplantation. Cell survival was assessed using tyrosine hydroxylase (TH) immunohistochemistry. A significant reduction in rotational scores was observed only in the group of animals receiving the combination of LTAC-treated donor cells and systemic LTAC administration. This functional improvement correlated with a significantly greater survival of TH-immunoreactive cells in this group of animals. The other groups had poor cell survival and no significant functional improvement. We conclude that a combination of systemic immunosuppression and treatment of the cell suspension with LTAC may be a superior strategy to optimize xenograft survival. This strategy may have important implications for clinical neural transplantation.
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Affiliation(s)
- A Y Alemdar
- Neural Transplantation Laboratory, Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada
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Bernhardt MK, Southard KA, Batterson KD, Logan HL, Baker KA, Jakobsen JR. The effect of preemptive and/or postoperative ibuprofen therapy for orthodontic pain. Am J Orthod Dentofacial Orthop 2001; 120:20-7. [PMID: 11455373 DOI: 10.1067/mod.2001.115616] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The control of pain during orthodontic treatment is of vital interest to both clinicians and patients. Surprisingly, there has been limited research into the control of orthodontic pain, and there is no standard of care for controlling this discomfort. The purpose of this study was to compare the effectiveness of preemptive ibuprofen therapy, postoperative ibuprofen therapy, and a combination of the 2 therapies. Forty-one orthodontic patients aged 9 years 3 months to 16 years 11 months who were to undergo separator placement were enrolled in this prospective study. Patients were randomly assigned to 1 of 3 experimental conditions: (1) 400 mg ibuprofen taken orally 1 hour before separator placement and 400 mg ibuprofen taken orally 6 hours after the initial dose, (2) 400 mg ibuprofen taken orally 1 hour before separator placement and a lactose capsule taken orally 6 hours after the initial dose, or (3) a lactose capsule taken orally 1 hour before separator placement and 400 mg ibuprofen taken 6 hours after the initial placebo. The results revealed that preemptive ibuprofen therapy significantly decreased pain that was experienced 2 hours after separator placement and at bedtime. Beginning on day 2, there was a trend for patients who had taken both preemptive and postoperative ibuprofen doses to have lower pain scores compared with the other 2 groups. In conclusion, these data indicate that ibuprofen taken 60 minutes before separator placement alleviates pain at 2 hours and at bedtime after treatment. Further study with the use of additional postoperative doses is warranted.
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Mukhida K, Baker KA, Sadi D, Mendez I. Enhancement of sensorimotor behavioral recovery in hemiparkinsonian rats with intrastriatal, intranigral, and intrasubthalamic nucleus dopaminergic transplants. J Neurosci 2001; 21:3521-30. [PMID: 11331381 PMCID: PMC6762505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
One of the critical variables that influences the efficacy of clinical neural transplantation for Parkinson's disease (PD) is optimal graft placement. The current transplantation paradigm that focuses on ectopic placement of fetal grafts in the striatum (ST) fails to reconstruct the basal ganglia circuitry or normalize neuronal activity in important basal ganglia structures, such as the substantia nigra (SN) and the subthalamic nucleus (STN). The aim of this study was to investigate a multitarget neural transplantation strategy for PD by assessing whether simultaneous dopaminergic transplants in the ST, SN, and STN induce functional recovery in hemiparkinsonian rats. Forty-six female Wistar rats with unilateral 6-hydroxydopamine lesions of the nigrostriatal pathway were randomly divided into eight groups and received lesions only or injections of 900,000 embryonic rat ventral mesencephalic cells in the (1) ST, (2) SN, (3) STN, (4) ST and SN, (5) ST, SN, and STN, (6) ST and STN, or (7) SN and STN. The number of cells transplanted was equally divided among grafting sites. Animals with two grafts received 450,000 cells in each structure, and animals with three grafts received 300,000 cells per structure. Recovery was assessed by amphetamine-induced rotations and the stepping tests. Graft survival was assessed using tyrosine hydroxylase immunohistochemistry. At 8 weeks after transplantation, simultaneous dopaminergic transplants in the ST, SN, and STN induced significant improvement in rotational behavior and stepping test scores. Intrastriatal transplants were associated with significant recovery of rotational asymmetry, whereas SN and STN transplants were associated with improved forelimb function scores. These results suggest that restoration of dopaminergic activity to multiple basal ganglia targets, such as the ST and SN, or the ST and STN, promotes a more complete functional recovery of complex sensorimotor behaviors. A multitarget transplant strategy aimed at optimizing dopaminergic reinnervation of the basal ganglia may be crucial in improving clinical outcomes in PD patients.
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Affiliation(s)
- K Mukhida
- Neural Transplantation Laboratory, Departments of Anatomy and Neurobiology and Surgery (Division of Neurosurgery), Dalhousie University, Halifax, Nova Scotia, Canada B3H 4H7
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Baker KA, Sadi D, Hong M, Mendez I. Simultaneous intrastriatal and intranigral dopaminergic grafts in the parkinsonian rat model: role of the intranigral graft. J Comp Neurol 2000; 426:106-16. [PMID: 10980486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The current transplantation strategy in experimental and clinical Parkinson's disease (PD) has been to place nigral dopaminergic grafts not in their ontogenic site (substantia nigra) but in their target area (striatum). Although intrastriatal dopaminergic grafts are capable of reinnervating the striatum, they fail to reinnervate the nigra, which may be an important factor limiting the efficacy of fetal tissue transplantation in parkinsonian patients. We have previously shown that simultaneous intrastriatal and intranigral dopaminergic grafts (double grafts) may provide a more complete restoration of the nigrostriatal circuitry (Mendez et al. [1996] J Neurosci 16:7216-7227; Mendez and Hong [1997] Brain Res 778:194-205). In the present study, we investigated the contribution of the intranigral graft to functional recovery in double-grafted hemiparkinsonian rats. Twenty Wistar rats with unilateral 6-hydroxydopamine (6-OHDA) lesions of the nigrostriatal pathway were divided into two groups and received either double grafts (n = 10) or intrastriatal grafts alone (n = 10). Following transplantation, both intrastriatally and double-grafted animals had a significant decrease in rotational behavior. However, only animals with double grafts exhibited a significant increase in contralateral adjusting step performance. The intranigral graft was subsequently lesioned by a second 6-OHDA injection. Following the second lesion, animals with double grafts exhibited a significant reversal of rotational behavior and a 51% reduction in contralateral adjusting step performance. The reversal in functional recovery correlated with a significant loss of intranigral grafted neurons. These results suggest that the intranigral graft has an important role in the functional recovery of double-grafted animals. Restoration of dopaminergic innervation to both the nigra and the striatum may be crucial for optimizing graft efficacy and may be a superior strategy in neural transplantation for PD.
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Affiliation(s)
- K A Baker
- Neural Transplantation Laboratory, Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada
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Baker KA. Antibiotic prophylaxis for selected implants and devices. J Calif Dent Assoc 2000; 28:620-6. [PMID: 11324123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Certain implants or devices are widely believed to put patients at risk from oral bacteremia. They include but are not limited to intravascular access devices, solid organ transplants, vascular grafts, coronary artery stents, breast implants, and penile prostheses. The purpose of this article is to review the risk of implant or device infection from transient bacteremia of oral origin and to provide recommendations for appropriate dental management. Since dental treatment bacteremias are a very rare cause of metastatic infections, attributing causality to dental treatment procedures can be viewed as unfounded in almost all cases.
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Affiliation(s)
- K A Baker
- University of Iowa Colleges of Dentistry and Pharmacy, USA.
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Flaitz CM, Baker KA. Treatment approaches to common symptomatic oral lesions in children. Dent Clin North Am 2000; 44:671-96. [PMID: 10925777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
A variety of oral mucosal lesions can be symptomatic in children. This article describes the classic clinical appearance of the most common oral diseases and provides treatment recommendations that are tailored to the pediatric age group. When possible, more than one drug alternative is given for each of the different oral conditions for an improved success rate. It is essential for the clinician to understand that this article should be used as a guide for managing oral and perioral lesions in children and adolescents. Specific dosages and formularies of drugs may require modification in the young child. Consultation with a primary care physician and pharmacist often is needed to ensure the best possible outcome, especially when immunosuppressive drugs are indicated. Most importantly, oral lesions that do not respond to therapeutic protocols should be referred to the appropriate specialist for definitive diagnosis and treatment.
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Affiliation(s)
- C M Flaitz
- Department of Oral and Maxillofacial Pathology, University of Texas Health Science Center at Houston, USA.
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Abstract
The clinical findings on neural transplantation for Parkinson's disease (PD) reported thus far are promising but many issues must be addressed before neural transplantation can be considered a routine therapeutic option for PD. The future of neural transplantation for the treatment of neurological disorders may rest in the discovery of a suitable alternative cell type for fetal tissue. One such alternative may be neurons derived from a human teratocarcinoma (hNT). hNT neurons have been shown to survive and integrate within the host brain following transplantation and provide functional recovery in animal models of stroke and Huntington's disease. In this study, we describe the transplantation of hNT neurons in the substantia nigra (SN) and striatum of the rat model for PD. Twenty-seven rats were grafted with one of three hNT neuronal products; hNT neurons, hNT-DA neurons, or lithium chloride (LiCl) pretreated hNT-DA neurons. Robust hNT grafts could be seen with anti-neural cell adhesion molecule and anti-neuron-specific enolase immunostaining. Immunostaining for tyrosine hydroxylase (TH) expression revealed no TH-immunoreactive (THir) neurons in any animals with hNT neuronal grafts. THir cells were observed in 43% of animals with hNT-DA neuronal grafts and all animals with LiCl pretreated hNT-DA neuronal grafts (100%). The number of THir neurons in these animals was low and not sufficient to produce significant functional recovery. In summary, this study has demonstrated that hNT neurons survive transplantation and express TH in the striatum and SN. Although hNT neurons are promising as an alternative to fetal tissue and may have potential clinical applications in the future, further improvements in enhancing TH expression are needed.
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Affiliation(s)
- K A Baker
- Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, B3H 4H7, Canada
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Mendez I, Baker KA, Hong M. Simultaneous intrastriatal and intranigral grafting (double grafts) in the rat model of Parkinson's disease. Brain Res Brain Res Rev 2000; 32:328-39. [PMID: 10751681 DOI: 10.1016/s0165-0173(99)00091-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Experimental and clinical studies of neural transplantation in Parkinson's disease have focused on the placement of fetal dopaminergic grafts not in their ontogenic site (substantia nigra) but in the main nigral target area (striatum). The reason for this is the apparent inability of intranigral nigral grafts to extend axons for long distances reinnervating the ipsilateral striatum. This review presents previous work by our laboratory [I. Mendez, M. Hong, Reconstruction of the striato-nigro-striatal circuitry by simultaneous double dopaminergic grafts: a tracer study using fluorogold and horseradish peroxidase, Brain Res. 778 (1997) 194-205; I. Mendez, D. Sadi, M. Hong., Reconstruction of the nigrostriatal pathway by simultaneous intrastriatal and intranigral dopaminergic transplants, J. Neurosci. 16 (1996) 7216-7227] using a new transplantation strategy aimed at restoring dopaminergic innervation of the nigra and striatum by simultaneous dopaminergic transplants placed in the substantia nigra and ipsilateral striatum (double grafts) in the 6-hydroxydopamine lesioned adult rat brain. These double grafts achieve not only greater striatal reinnervation than the standard intrastriatal grafts but also produce a faster and more complete behavioural recovery six weeks after transplantation. Injection of the retrograde tracer fluorogold into the striatum and nigra resulted in fluorescent labeled cells within the intranigral graft and the intrastriatal graft and surrounding striatum, respectively suggesting that these double grafts promote at least partial reconstruction of the nigrostriatal dopaminergic pathway. This double graft strategy may have potential implications in clinical neural transplantation for Parkinson's disease.
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Affiliation(s)
- I Mendez
- Neural Transplantation Laboratory, Departments of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada.
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Abstract
RSV is the most important respiratory pathogen in infants and young children. About 1% of primary RSV infections result in hospitalization. The virus is spread by large droplets of secretions or contact with contaminated secretions. Infants infected with RSV may demonstrate poor feeding, rhinorrhea, apnea, lethargy, wheezing, and respiratory distress. Diagnosis may be made by clinical signs and symptoms (especially those observed during epidemics), by chest radiographs showing hyperinflation, or by rapid antigen detection with immunofluorescence of nasopharyngeal aspirates. Risk factors for severe disease accompanied by complications include chronic heart disease, chronic lung disease, immunodeficiency, HIV, and prematurity. Immunity is incomplete and of short duration, and reinfection is common. Treatment remains supportive and consists of oxygen administration, hydration, and diligent monitoring. Use of corticosteroids, bronchodilators, antibiotics, and ribavirin is controversial and is dependent largely on physician preference. Use of ribavirin should be reserved for patients who have severe underlying conditions associated with increased mortality rates. Intravenous RSV Ig has been replaced by palivizumab, which is generally recommended for infants at high risk for severe RSV, including those with a history of prematurity and those with chronic lung disease.
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Affiliation(s)
- K A Baker
- Department of Pediatrics, Penn State Geisinger Health System, Danville, USA
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MacDonald RC, Ashley GW, Shida MM, Rakhmanova VA, Tarahovsky YS, Pantazatos DP, Kennedy MT, Pozharski EV, Baker KA, Jones RD, Rosenzweig HS, Choi KL, Qiu R, McIntosh TJ. Physical and biological properties of cationic triesters of phosphatidylcholine. Biophys J 1999; 77:2612-29. [PMID: 10545361 PMCID: PMC1300535 DOI: 10.1016/s0006-3495(99)77095-5] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The properties of a new class of phospholipids, alkyl phosphocholine triesters, are described. These compounds were prepared from phosphatidylcholines through substitution of the phosphate oxygen by reaction with alkyl trifluoromethylsulfonates. Their unusual behavior is ascribed to their net positive charge and absence of intermolecular hydrogen bonding. The O-ethyl, unsaturated derivatives hydrated to generate large, unilamellar liposomes. The phase transition temperature of the saturated derivatives is very similar to that of the precursor phosphatidylcholine and quite insensitive to ionic strength. The dissociation of single molecules from bilayers is unusually facile, as revealed by the surface activity of aqueous liposome dispersions. Vesicles of cationic phospholipids fused with vesicles of anionic lipids. Liquid crystalline cationic phospholipids such as 1, 2-dioleoyl-sn-glycero-3-ethylphosphocholine triflate formed normal lipid bilayers in aqueous phases that interacted with short, linear DNA and supercoiled plasmid DNA to form a sandwich-structured complex in which bilayers were separated by strands of DNA. DNA in a 1:1 (mol) complex with cationic lipid was shielded from the aqueous phase, but was released by neutralizing the cationic charge with anionic lipid. DNA-lipid complexes transfected DNA into cells very effectively. Transfection efficiency depended upon the form of the lipid dispersion used to generate DNA-lipid complexes; in the case of the O-ethyl derivative described here, large vesicle preparations in the liquid crystalline phase were most effective.
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Affiliation(s)
- R C MacDonald
- Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, Illinois 60208, USA.
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Abstract
Paramyxoviruses are responsible for significant human mortality and disease worldwide, but the molecular mechanisms underlying their entry into host cells remain poorly understood. We have solved the crystal structure of a fragment of the simian parainfluenza virus 5 fusion protein (SV5 F), revealing a 96 A long coiled coil surrounded by three antiparallel helices. This structure places the fusion and transmembrane anchor of SV5 F in close proximity with a large intervening domain at the opposite end of the coiled coil. Six amino acids, potentially part of the fusion peptide, form a segment of the central coiled coil, suggesting that this structure extends into the membrane. Deletion mutants of SV5 F indicate that putative flexible tethers between the coiled coil and the viral membrane are dispensable for fusion. The lack of flexible tethers may couple a final conformational change in the F protein directly to the fusion of two bilayers.
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Affiliation(s)
- K A Baker
- Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, Illinois 60208-3500, USA
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31
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Abstract
Systemic therapy emphasizes the importance of understanding each relationship in the context of its ecosystem. Considerations such as the influence of social agencies, culture, and the therapist's self-awareness are described in the literature as amplifying lenses within the therapeutic relationship. When a minority client is caught in the web of larger system agencies and is mandated to family therapy, systemic family therapy, which incorporates multiple lenses and attends to the context of social background, may provide a better understanding of the client's reality. Clinical cases show that therapists may slip into veiled racist and discriminatory attitudes with minority clients. Self-awareness, "soul searching," and appropriate supervision may be of tremendous help in learning from such experiences. A case example illustrates the application of this approach.
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Affiliation(s)
- K A Baker
- Department of Behavioral Sciences, Yezreel Academic College, Akko, Israel
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Galant SP, Lawrence M, Meltzer EO, Tomasko M, Baker KA, Kellerman DJ. Fluticasone propionate compared with theophylline for mild-to-moderate asthma. Ann Allergy Asthma Immunol 1996; 77:112-8. [PMID: 8760776 DOI: 10.1016/s1081-1206(10)63496-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The inhaled corticosteroid, fluticasone propionate, was compared with the oral bronchodilator theophylline in the maintenance treatment of asthma. OBJECTIVE The objective of the present study was to compare the efficacy and safety of twice-daily inhaled fluticasone propionate, 50 micrograms, and fluticasone propionate, 100 micrograms, with that of theophylline in the maintenance treatment of mild-to-moderate asthma. METHODS In this randomized, double-blind, placebo-controlled, parallel-group study, 353 adult and adolescent patients with asthma inadequately controlled with inhaled beta-agonist therapy alone received fluticasone propionate, 50 micrograms, or fluticasone propionate, 100 micrograms, by metered-dose inhaler; theophylline capsules; or placebo twice daily for 12 weeks. Only inhaled albuterol was permitted as needed for acute symptoms. RESULTS Both fluticasone propionate groups had a significantly greater probability of remaining in the study (ie, meeting asthma stability criteria) than did either the theophylline or placebo group (P < or = .008); 39% and 51% in the theophylline and placebo groups, respectively, were withdrawn due to lack of treatment efficacy compared with 14% and 21% in the fluticasone propionate, 50 micrograms, and fluticasone propionate, 100 micrograms, groups. Both fluticasone propionate groups experienced significantly greater improvement in FEV1 and PEF compared with patients in the theophylline or placebo group (P < or = .004). The incidence of potentially drug-related adverse events was significantly greater in the theophylline group (25%) than in the placebo group (11%) (P = .031), while there were no differences between placebo and fluticasone propionate, 50 micrograms, (18%) or fluticasone propionate 100 micrograms, (22%). CONCLUSION Twice daily treatment with inhaled fluticasone propionate 50 micrograms or 100 micrograms was significantly more effective than theophylline in the treatment of mild-to-moderate asthma.
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Affiliation(s)
- S P Galant
- Adult and Pediatric Allergy and Clinical Immunology, Orange, California, USA
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33
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Zaplatin AN, Baker KA, Kleinhans FW. Effectiveness and toxicity of several DTPA broadening agents for biological ESR spectroscopy. J Magn Reson B 1996; 110:249-54. [PMID: 8867440 DOI: 10.1006/jmrb.1996.0040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The effectiveness of a standard ESR broadening agent, potassium trioxalatochromiate (CrOx), for use with the spin-label tempone, was compared to that of diethylenetriaminepentaacetic acid (DTPA) containing an ion (Gd, Cr, Mn, Fe) with a large magnetic moment. Signal attenuation, line broadening, toxicity, and cell membrane permeability were compared. As a broadening agent, CrOx was most effective, followed by Fe-DTPA. CrOx proved mildly toxic while Gd-DTPA and Fe-DTPA were virtually non-toxic. The human red blood cell membrane was tested for permeability to Fe- and Gd-DTPA and found to be impermeable to both. In situations where toxicity to cells is critical, the DTPA chelates, particularly Fe-DTPA, may prove an acceptable substitute for CrOx.
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Affiliation(s)
- A N Zaplatin
- Department of Physics, IUPUI, Indianapolis, Indiana 46202, USA
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Baker KA, DeVos D. Safety considerations with high field MRI. Radiol Technol 1996; 67:251-2. [PMID: 8850258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Affiliation(s)
- K A Baker
- Department of Oral and Maxillofacial Surgery, College of Dentistry, University of Iowa, Iowa City, USA
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Baker KA, Fotos PG. The management of odontogenic infections. A rationale for appropriate chemotherapy. Dent Clin North Am 1994; 38:689-706. [PMID: 7805942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Odontogenic infections are one of the most frequently occurring infectious processes known to health practice. Significant changes have occurred in the use of antibiotics and antimicrobials since the use of chemotherapeutic agents became widespread. This article provides some important considerations for selecting appropriate chemotherapeutic agents during the management of odontogenic infections.
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Affiliation(s)
- K A Baker
- Department of Oral Pathology, Radiology, and Medicine, University of Iowa College of Dentistry, Iowa City
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Vincent SD, Lilly GE, Baker KA. Clinical, historic, and therapeutic features of cicatricial pemphigoid. A literature review and open therapeutic trial with corticosteroids. Oral Surg Oral Med Oral Pathol 1993; 76:453-9. [PMID: 8233425 DOI: 10.1016/0030-4220(93)90012-s] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Cicatricial pemphigoid is at present an incurable, autoimmune disease that involves mucosa and skin. We have documented the clinical, microscopic, and therapeutic features of 23 patients with cicatricial pemphigoid and added these to reports of past literature. The mean age at the time of diagnosis was 63 years, and women were involved twice as often as men. Eighty-three percent of patients had oral mucosal involvement, 70% had conjunctival involvement, and 22% had skin involved. Direct immunologic evaluation revealed IgG at the basement membrane in 57% of cases and C3 in 66%. We have been able to manage the disease adequately in most patients with topical or systemic corticosteroids. The most commonly encountered side effect was oral candidiasis.
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Affiliation(s)
- S D Vincent
- Department of Oral Pathology, Radiology, and Medicine, University of Iowa College of Dentistry, Iowa City
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St John RE, Baker KA. Pressure-controlled inverse-ratio ventilation. Crit Care Nurs Clin North Am 1991; 3:621-7. [PMID: 1777198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The routine use of PCIRV in adult critical illness remains an area of considerable controversy and debate. This stems in large part from a lack of well-controlled studies demonstrating improved patient outcome over conventional mechanical ventilation techniques. Although it is unlikely that clinicians will stop using PCIRV until such data are available, nurses and other caregivers should exercise caution whenever this form of therapy is employed.
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Abstract
The institutionalized elderly use more drugs per capita than do other segments of the population and are more likely than other population groups to have adverse drug reactions. Many of these drugs could affect oral health or dental treatment. This paper provides data on the frequency with which a population of nursing home residents took medications with possible oral effects. Information regarding prescription and nonprescription drug use was obtained from nursing home records of 481 subjects. Nine medication effect categories of possible significance in dentistry were established. Dentists treating institutionalized patients must be knowledgeable about patient drug use because 94% of this institutionalized population were taking medications that could alter oral health or dental treatment.
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Affiliation(s)
- K A Baker
- Department of Oral and Maxillofacial Surgery, University of Iowa, Iowa City 52242
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Brodine WN, Baker KA, Kirchmer JT, Chiarelli TE. Simultaneous, multiple point mapping during surgery for Wolff-Parkinson-White syndrome without the use of a computer. Pacing Clin Electrophysiol 1990; 13:1096-100. [PMID: 1700382 DOI: 10.1111/j.1540-8159.1990.tb02164.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Epicardial mapping of patients undergoing surgical correction of the Wolff-Parkinson-White syndrome is usually accomplished by using a single point probe. This somewhat tedious and time consuming method has been streamlined by computer-based systems allowing multiple simultaneous point maps to be developed either by electrodes applied as a band around the atrioventricular groove or a sock over the ventricle. Because the computer technology required to access, analyze, and display this data is not widely available, a system was devised to display ten simultaneous electrograms from a wrap of ten electrodes placed about the atrial or ventricular side of the atrioventricular groove. Using this technique three patients undergoing surgery for accessory pathway removal were accurately and quickly mapped allowing surgical cure of the preexcitation in each case.
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Affiliation(s)
- W N Brodine
- Cardiac Electrophysiology Laboratory, Research Medical Center, Kansas City, Missouri
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41
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Vincent SD, Fotos PG, Baker KA, Williams TP. Oral lichen planus: the clinical, historical, and therapeutic features of 100 cases. Oral Surg Oral Med Oral Pathol 1990; 70:165-71. [PMID: 2290644 DOI: 10.1016/0030-4220(90)90112-6] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Lichen planus is a chronic inflammatory epidermal and mucosal disease, the cause of which is poorly understood. We reviewed the clinical and historic features of 100 patients referred to our clinic for diagnosis and management of lichen planus. The age, gender, chief complaint, duration of the chief complaint, medical history, medications, and clinical findings were recorded. Past therapeutic modalities were reviewed. Of therapeutic significance, 25 patients with oral lichen planus had a secondary oral candidiasis. Management of symptomatic lichen planus with topical and systemic steroid is discussed. The pharmacology of topical and systemic steroid usage and the rationale for treatment are discussed.
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Affiliation(s)
- S D Vincent
- Department of Oral Pathology and Diagnosis, University of Iowa College of Dentistry, Iowa City
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Levy SM, Baker KA, Semal TP, Kohout FJ. Use of medications with dental significance by a non-institutionalized elderly population. Gerodontics 1988; 4:119-25. [PMID: 3209033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Abstract
Interprofessional contact and consultation among dentists, physicians, and pharmacists can help to optimize patient care. Because pharmacists are readily accessible to the public, their influence is essential for the appropriate prescribing and continued use of systemic fluoride supplements. Pharmacists should be familiar with various aspects of fluoride therapy, such as mechanisms of caries inhibition, dosages associated with acute and chronic toxicity, and recommended daily dosage levels. The impact of breastfeeding, multiple sources of water intake, and changing age of the patient must be considered in determining proper systemic fluoride dosage. Pharmacists should consult with both physicians and dentists to coordinate water fluoride assay and prescribing responsibilities. They also can help to educate both prescribers and patients. Because of frequent patient contact and access to medication records, pharmacists can encourage and monitor patient compliance. Fluoride prescriptions and results of water fluoride assays should be documented on the patients' computerized or card profiles. In addition, pharmacists can counsel patients about the fluoride ion content of various home-use products and make recommendations to ensure that an optimal level of fluoride ingestion is maintained.
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Abstract
A 62-year-old woman with reported allergies to procaine and lidocaine requested dental care. Consultation with the patient, the patient's physicians, and the patient's dentists did not identify the causes of the adverse reactions had occurred only when anesthetic was administered without vasoconstrictor. There were no reactions when vasoconstrictor was used. Skin testing by an allergist disclosed no evidence of true allergic reaction to any of the 'caine drugs. In addition, no evidence of reaction to preservatives was found during patch testing. The adverse reactions were determined to be caused by an idiosyncratic low threshold to toxic side effects of 'caine drugs. The use of vasoconstrictor (epinephrine) apparently promoted the retention of the anesthetic locally and prevented systemic absorption sufficient to cause the toxic reaction. Practitioners must be aware that adverse reactions to dental anesthetic may be a result of true allergy, psychogenic reaction (syncope), normal toxic overdose, or idiosyncratic toxic overdose.
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Baker KA, Ettinger RL. Intra-oral effects of drugs in elderly persons. Gerodontics 1985; 1:111-6. [PMID: 3861442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Baker KA, Taylor JW, Lilly GE. Treatment of trigeminal neuralgia: use of baclofen in combination with carbamazepine. Clin Pharm 1985; 4:93-6. [PMID: 3971692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A patient with trigeminal neuralgia who became refractory to carbamazepine but responded well to the addition of baclofen to his regimen is described, and the drug and surgical treatment of trigeminal neuralgia are discussed. A 57-year-old white man sought medical help following a six-week history of paroxysmal pain in the right jaw. Rubbing the skin in the right third division of the trigeminal nerve produced a paroxysm of pain. Trigeminal neuralgia was diagnosed, and carbamazepine therapy was initiated with good results. Pain recurred upon discontinuation of the therapy, and carbamazepine was restarted. However, debilitating pain persisted despite continuous treatment that produced moderate postdose ataxia. Baclofen was added to the patient's regimen and increased to 60 mg daily with subsequent reductions in the carbamazepine dosages. The patient remained pain-free during the following 10 months. Carbamazepine is considered the drug of choice and is initially very effective in treating trigeminal neuralgia. However, many patients are forced to discontinue drug therapy because of intolerance or ineffectiveness and are faced with surgery as their only option. Baclofen does not appear to be as effective as carbamazepine when used as a single agent. However, its apparent synergism with carbamazepine and phenytoin combined with its low incidence of serious side effects make baclofen a valuable adjunct in the treatment of refractory trigeminal neuralgia.
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Abstract
Salt taste detection thresholds have been measured by a forced-choice, up-down sip method in 146 healthy subjects aged 10-95 years, and in 43 ill elderly patients. Thresholds are shown to increase log linearly with age after the age of 20 years. Thresholds are higher in smokers than non-smokers and the lower thresholds of women are accounted for by their lower prevalence of smoking. Ill patients have higher thresholds than healthy subjects of the same age and this is not specifically associated with any diagnosis. The methodology of taste threshold measurement and earlier studies of taste thresholds are reviewed.
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Kulig SG, Baker KA. Preliminary field-testing of The Physician's Developmental Quick Screen for Speech Disorders ("PDQ"). A 5-minute procedure for testing children six months to six years. Clin Pediatr (Phila) 1976; 15:1146-50. [PMID: 991531 DOI: 10.1177/000992287601501212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
This report describes the development of The Physician's Developmental Quick Screen for Speech Disorders (the PDQ), a screening test designed for use by nonspeech pathologists with children aged six months to six years. Disorders of language, articulation, voice, rhythm of speech, and the speaking mechanism are considered by the PDQ. Validation studies resulted in 90 per cent agreement (p less than .001) between nonspeech pathologists utilizing the PDQ and speech pathologists employing a battery of more established tests.
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Kulig SG, Baker KA, Levine HG. Screening for speech and language disorders: a training program for physicians and allied health professionals. ASHA 1975; 17:507-11. [PMID: 1164444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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