175 results on '"Peters AC"'
Search Results
2. An evaluation of HACCP implementation status in UK small and medium enterprises in food manufacturing
- Author
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Fielding, LM, primary, Ellis, L, additional, Beveridge, C, additional, and Peters, AC, additional
- Published
- 2005
- Full Text
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3. Long-term prognosis of cerebral venous sinus thrombosis in childhood
- Author
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De Schryver, Els LLM, primary, Blom, Ingrid, additional, Braun, Kees PJ, additional, Jaap Kappelle, L, additional, Rinkel, Gabriël JE, additional, Boudewyn Peters, AC, additional, and Jennekens-Schinkel, Aag, additional
- Published
- 2004
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4. Paediatric Neurology in Clinical General Practice
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Appleton, Richard, primary and Peters, AC, additional
- Published
- 2002
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5. LEVELS OF MESSENGER-RNA CODING FOR DNA TOPOISOMERASE-II ISOFORMS DO NOT CORRELATE WITH IN-VITRO DRUG-SENSITIVITY
- Author
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PETERS, AC, primary, SMYTHE, AM, additional, WU, L, additional, MONKS, A, additional, BOYD, MR, additional, and SHOEMAKER, RH, additional
- Published
- 1994
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6. Fukuyama type congenital muscular dystrophy—Two Dutch siblings—
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Peters, AC Boudewyn, primary, Bote, Gerard Th AM, additional, Roos, Raymund AC, additional, and van Gelderen, Hans H, additional
- Published
- 1984
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7. Barriers and pathways to environmental surveillance of antibiotic resistance in middle- and low-income settings: a qualitative exploratory key expert study.
- Author
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Peters AC, Larsson DGJ, Laxminarayan R, and Munthe C
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- Humans, Developing Countries, Environmental Monitoring methods, Interviews as Topic, Global Health, Grounded Theory, Qualitative Research, Drug Resistance, Microbial
- Abstract
Background: Local and global surveillance of antibiotic resistance (ABR) has proven a challenge to implement effectively in low- and middleincome (LMI) settings. Environmental surveillance solutions are increasingly highlighted as a strategy to help overcome such problems, and thus to promote global health as well as the local management of ABR in LMI countries. While technical and scientific aspects of such solutions are being probed continuously, no study has investigated their practical feasibility., Objective: Explore practical barriers for environmental surveillance of ABR in LMI countries, and pathways for surveillance experts to manage these., Methods: To start charting this unknown territory, we conducted an explorative, qualitative interview study with key informants, applying a constructivist grounded theory approach to analyze the results., Results: Barriers were identified across infrastructural, institutional and social dimensions, and pathways to manage them were mostly counterproductive from an ABR management perspective, including avoiding entire regions, applying substandard methods and failing to include local collaborators., Conclusion: The research community as well as international agencies, organizations and states have key roles and responsibilities for improving the prospects of feasible environmental ABR surveillance in LMI-settings.
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- 2024
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8. Echocardiographic parameters associated with less reverse left ventricular remodeling after transcatheter aortic valve implant in subjects with prosthesis patient mismatch.
- Author
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Peters AC, Gong FF, Ramesh A, Andrei A, Jankowski M, Cantey E, Chen V, Thomas JD, Flaherty JD, Malaisrie SC, and Maganti K
- Subjects
- Humans, Aortic Valve diagnostic imaging, Aortic Valve surgery, Retrospective Studies, Ventricular Remodeling, Treatment Outcome, Echocardiography, Aortic Valve Stenosis, Heart Valve Prosthesis, Heart Valve Prosthesis Implantation, Transcatheter Aortic Valve Replacement
- Abstract
Background: Transaortic valve implant (TAVI) is the treatment of choice for severe aortic stenosis (AS). Some patients develop prosthesis patient mismatch (PPM) after TAVI. It is challenging to determine which patients are at risk for clinical deterioration., Methods: We retrospectively measured echocardiographic parameters of left ventricular (LV) morphology and function, prosthetic aortic valve effective orifice area (iEOA) and hemodynamics in 313 patients before and 1 year after TAVI. Our objective was to compare the change in echocardiographic parameters associated with left ventricular reverse modeling in subjects with and without PPM. Our secondary objective was to evaluate echo parameters associated with PPM and the relationship to patient functional status and survival post-TAVI., Results: We found that 82 (26.2%) of subjects had moderate and 37 (11.8%) had severe PPM post-TAVI. There was less relative improvement in LVEF with PPM (1.9 ± 21.3% vs. 8.2 + 30.1%, p = .045). LV GLS also exhibited less relative improvement in those with PPM (13.4 + 34.1% vs. 30.9 + 73.3%, p = .012). NYHA functional class improved in 84.3% of subjects by one grade or more. Echocardiographic markers of PPM were worse in those without improvement in NYHA class (mean AT/ET was .29 vs. .27, p = .05; DVI was .46 vs. .51, p = .021; and iEOA was .8 cm/m
2 vs. .9 cm/m2 , p = .025). There was no association with PPM and survival., Conclusions: There was no improvement in LVEF and less improvement in LV GLS in those with PPM post-TAVI. Echocardiographic markers of PPM were present in those with lack of improvement in NYHA functional class., (© 2023 The Authors. Echocardiography published by Wiley Periodicals LLC.)- Published
- 2024
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9. Relationship between left atrial reservoir strain, volumes, and geometry: Insights from simple theoretical model.
- Author
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Peters AC, Lee J, Jankowski M, and Thomas JD
- Subjects
- Humans, Heart Atria diagnostic imaging, Echocardiography methods, Models, Theoretical, Atrial Fibrillation, Atrial Appendage
- Abstract
Background: Left atrial (LA) volume is related to LA reservoir strain (LAS
R ), but the relationship is not fully resolved. We sought to model the relationship between LA end-diastolic and end-systolic volumes (LAEDV and LAESV) and LASR based on a geometrical approach to exploit the relationship between LASR and volume., Methods: Modeling the LA as a hemisphere with radius r, LASR was recognized to vary linearly with r and LA volume with r3 . Expanding this cubic relation as a Taylor series resulted in a simple linear equation: LAESV/LAEDV = 1 + 3 × LASR . To validate this, 52 transthoracic echocardiograms were analyzed from 18 patients who underwent transcatheter edge-to-edge repair (TEER) with MitraClip with serial assessment pre-procedure, 1 month post-clip, and 12 months post-TEER. Linear regression was performed to compare the geometric equation to a statistical model created by a line of best fit to relate LAESV/LAEDV to LASR ., Results: The statistical and geometric model both resulted in a strong correlation (r = .8, p < .001, respectively). The slope of the line in the statistical model was 3.3, which was statistically indistinguishable from the expected slope of 3 based on the geometric model (Figure 2A). Using the geometric model to compare the measured versus calculated LAESV/LAEDV also resulted in a strong correlation (r = .8, p < .001)(Figure 2B)., Conclusion: We describe the relationship between LA volume and strain mathematically by considering the geometry of the LA. This model enhances our understanding of the interaction between atrial strain and volume. Further research is necessary to validate this using 3D atrial volumes in a broader cohort of subjects., (© 2023 Wiley Periodicals LLC.)- Published
- 2023
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10. Pushing forward public mental health agenda and promotion of mental health.
- Author
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Wasserman D, Arango C, Fiorillo A, Levin S, Peters AC, Rao GP, Sylla A, and Sanchez-Villanueva T
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- 2023
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11. Depletion of polyfunctional CD26 high CD8 + T cells repertoire in chronic lymphocytic leukemia.
- Author
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Bozorgmehr N, Hnatiuk M, Peters AC, and Elahi S
- Abstract
Background: CD8
+ T cells play an essential role against tumors but the role of human CD8+ CD26+ T cell subset against tumors, in particular, haematological cancers such as chronic lymphocytic leukemia (CLL) remains unknown. Although CD4+ CD26high T cells are considered for adoptive cancer immunotherapy, the role of CD8+ CD26+ T cells is ill-defined. Therefore, further studies are required to better determine the role of CD8+ CD26+ T cells in solid tumors and haematological cancers., Methods: We studied 55 CLL and 44 age-sex-matched healthy controls (HCs). The expression of CD26 on different T cell subsets (e.g. naïve, memory, effector, and etc.) was analyzed. Also, functional properties of CD8+ CD26+ and CD8+ CD26- T cells were evaluated. Finally, the plasma cytokine/chemokine and Galectin-9 (Gal-9) levels were examined., Results: CD26 expression identifies three CD8+ T cell subsets with distinct immunological properties. While CD26neg CD8+ T cells are mainly transitional, effector memory and effectors, CD26low CD8+ T cells are mainly naïve, stem cell, and central memory but CD26high T cells are differentiated to transitional and effector memory. CD26+ CD8+ T cells are significantly reduced in CLL patients versus HCs. CD26high cells are enriched with Mucosal Associated Invariant T (MAIT) cells co-expressing CD161TVα7.2 and IL-18Rα. Also, CD26high cells have a rich chemokine receptor profile (e.g. CCR5 and CCR6), profound cytokine (TNF-α, IFN-γ, and IL-2), and cytolytic molecules (Granzyme B, K, and perforin) expression upon stimulation. CD26high and CD26low T cells exhibit significantly lower frequencies of CD160, 2B4, TIGIT, ICOS, CD39, and PD-1 but higher levels of CD27, CD28, and CD73 versus CD26neg cells. To understand the mechanism linked to CD26high depletion, we found that malignant B cells by shedding Galectin-9 (Gal-9) contribute to the elevation of plasma Gal-9 in CLL patients. In turn, Gal-9 and the inflammatory milieu (IL-18, IL-12, and IL-15) in CLL patients contribute to increased apoptosis of CD26high T cells., Conclusions: Our results demonstrate that CD26+ T cells possess a natural polyfunctionality to traffic and exhibit effector functions and resist exhaustion. Therefore, they can be proposed for adoptive cancer immunotherapy. Finally, neutralizing and/or inhibiting Gal-9 may preserve CD26high CD8+ T cells in CLL., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)- Published
- 2023
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12. Tumor Infiltrating Lymphocytes Predict Survival in Solid Organ Transplant Recipients With Monomorphic Post-transplant Lymphoproliferative Disorders.
- Author
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Stubbins RJ, Lam R, Zhu J, Ghosh S, Mabilangan C, Kuruvilla J, Goswami RS, Lai R, Preiksaitis JK, Jain MD, and Peters AC
- Subjects
- Humans, Lymphocytes, Tumor-Infiltrating pathology, Middle Aged, Prognosis, Retrospective Studies, Tumor Microenvironment, Epstein-Barr Virus Infections complications, Lymphoma complications, Lymphoproliferative Disorders diagnosis, Lymphoproliferative Disorders etiology, Organ Transplantation adverse effects
- Abstract
Introduction: The tumor microenvironment (TME) in post-transplant lymphoproliferative disorders (PTLDs) remains unexplored. Tumor infiltrating lymphocytes (TILs) are prognostic in other lymphomas. We assessed the prognostic impact of TILs in monomorphic B-cell PTLD., Methods: TIL density (CD3+ cells/mm
2 ) was determined by CD3 immunohistochemistry in archived diagnostic biopsies from patients diagnosed with monomorphic B-cell PTLD., Results: Amongst monomorphic PTLDs (N = 107), low TIL-count was associated with inferior 2-year progression-free survival (PFS) (41% versus 86%, P = .003) and 2-year overall survival (OS) (52% versus 93%, P = .003) by Kaplan-Meier analysis. Low TIL-count was significant on Cox univariate regression for inferior PFS (HR 4.5, 95% CI 2.0-9.9, P < .001) and OS (HR 4.6, 95% CI 1.8-11.8, P < .001). Multivariate analysis with clinical variables (age ≥60 years, high LDH, stage III/IV, CNS involvement) and TIL-count showed significance for PFS (HR 3.3, 95% CI 1.3-8.3, P = .010) and a non-significant trend for OS (HR 2.6, 95% CI 0.9-7.3, P = .064). A composite score including TILs and clinical variables (age ≥60 years, high LDH, stage III/IV, CNS involvement) effectively stratified monomorphic PTLD patients by PFS and OS (2-year OS: low-risk 93%, intermediate-risk 61%, high-risk 23%, P < .001)., Conclusions: The TME and TILs are prognostically relevant in monomorphic PTLD. Prognostic models including measures of the TME may improve risk stratification for patients with monomorphic PTLDs., Competing Interests: Declaration of Competing Interest AP has attended advisory boards for Janssen, AstraZenica, Roche, Abbvie, Gilead, an Seattle Genetics. She has received honoraria from Janssen, Gilead, and Abbvie. MJ has acted in advisory and consultancy roles for Kite/Gilead, Novartis, BMS, and Takeda. JK has received honoraria from AbbVie, Bristol Myers Squibb, Amgen, AstraZeneca, Celgene, Gilead Sciences, Janssen, Karyopharm Therapeutics, Merck, Novartis, Roche, and Seattle Genetics; has consultancy or advisory roles with AbbVie, Bristol Myers Squibb, Gilead Sciences, Karyopharm Therapeutics, Merck, Roche/Genentech, and Seattle Genetics; and has received research grants or funding from Janssen and Roche. All other authors did not report any relevant conflict of interest disclosures., (Copyright © 2022. Published by Elsevier Inc.)- Published
- 2022
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13. SemClinBr - a multi-institutional and multi-specialty semantically annotated corpus for Portuguese clinical NLP tasks.
- Author
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Oliveira LESE, Peters AC, da Silva AMP, Gebeluca CP, Gumiel YB, Cintho LMM, Carvalho DR, Al Hasan S, and Moro CMC
- Subjects
- Electronic Health Records, Humans, Portugal, Reproducibility of Results, Medicine, Natural Language Processing
- Abstract
Background: The high volume of research focusing on extracting patient information from electronic health records (EHRs) has led to an increase in the demand for annotated corpora, which are a precious resource for both the development and evaluation of natural language processing (NLP) algorithms. The absence of a multipurpose clinical corpus outside the scope of the English language, especially in Brazilian Portuguese, is glaring and severely impacts scientific progress in the biomedical NLP field., Methods: In this study, a semantically annotated corpus was developed using clinical text from multiple medical specialties, document types, and institutions. In addition, we present, (1) a survey listing common aspects, differences, and lessons learned from previous research, (2) a fine-grained annotation schema that can be replicated to guide other annotation initiatives, (3) a web-based annotation tool focusing on an annotation suggestion feature, and (4) both intrinsic and extrinsic evaluation of the annotations., Results: This study resulted in SemClinBr, a corpus that has 1000 clinical notes, labeled with 65,117 entities and 11,263 relations. In addition, both negation cues and medical abbreviation dictionaries were generated from the annotations. The average annotator agreement score varied from 0.71 (applying strict match) to 0.92 (considering a relaxed match) while accepting partial overlaps and hierarchically related semantic types. The extrinsic evaluation, when applying the corpus to two downstream NLP tasks, demonstrated the reliability and usefulness of annotations, with the systems achieving results that were consistent with the agreement scores., Conclusion: The SemClinBr corpus and other resources produced in this work can support clinical NLP studies, providing a common development and evaluation resource for the research community, boosting the utilization of EHRs in both clinical practice and biomedical research. To the best of our knowledge, SemClinBr is the first available Portuguese clinical corpus., (© 2022. The Author(s).)
- Published
- 2022
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14. Temporal trends in right heart strain in patients undergoing pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension.
- Author
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Peters AC, Madhan AS, Kislitsina O, Elenbaas C, Nishtala A, Freed B, Schimmel D, Thomas JD, Cuttica M, and Malaisrie SC
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- Endarterectomy, Humans, Vascular Resistance, Ventricular Function, Right, Hypertension, Pulmonary diagnostic imaging, Hypertension, Pulmonary surgery, Pulmonary Embolism complications, Pulmonary Embolism diagnostic imaging, Pulmonary Embolism surgery, Ventricular Dysfunction, Right
- Abstract
Background: Pulmonary thromboendarterectomy (PTE) is a curative procedure for chronic thromboembolic pulmonary hypertension (CTEPH). Right ventricular free wall strain (RV FWS) and right atrial strain (RAS) are not well studied in a CTEPH population. We sought to determine temporal trends in RAS and RV FWS in patients post-PTE., Methods: 28 patients undergoing PTE for CTEPH were prospectively enrolled in a surgical database. Comprehensive echocardiographic assessment of the right heart was performed including RV FWS, right atrial volume, and the three components of RAS: reservoir, conduit, and booster strain., Results: Patients undergoing PTE demonstrated improvement in NYHA functional class (P < 0.001). Hemodynamic assessment showed improvement in mean pulmonary artery pressure from 49.7 ± 8.5 mm Hg to 23.9 ± 6.5 mm Hg (P < 0.001) and pulmonary vascular resistance decreased from 7.8 ± 3.2 wu to 2.4 ± 1.3 wu (P < 0.001). Tricuspid annular plane systolic excursion (TAPSE) and lateral S` declined immediately post-op. RV FWS improved from -14.4 ± 4% to -19 ± 3.4% post-op and -21.2 ± 4.7% at long-term follow-up (P < 0.001). Improvement in RV FWS post-op was driven primarily by increases in the apical and mid segments. RA volume declined significantly during the study period. RA reservoir and conduit strain improved after PTE., Conclusion: Patients undergoing PTE for CTEPH had significant improvement in right heart hemodynamics immediately post-op. Traditional echo metrics of RV performance including TAPSE and lateral S` did not improve. RV FWS improved, which was driven by changes in the apical and mid segments. This highlights that RV FWS is a viable and useful metric to follow in CTEPH patients post-PTE., (© 2021 Wiley Periodicals LLC.)
- Published
- 2021
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15. Expanded antigen-experienced CD160 + CD8 + effector T cells exhibit impaired effector functions in chronic lymphocytic leukemia.
- Author
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Bozorgmehr N, Okoye I, Oyegbami O, Xu L, Fontaine A, Cox-Kennett N, Larratt LM, Hnatiuk M, Fagarasanu A, Brandwein J, Peters AC, and Elahi S
- Subjects
- Aged, Aged, 80 and over, Case-Control Studies, Cell Proliferation, Cells, Cultured, Cytokines blood, Extracellular Vesicles immunology, Extracellular Vesicles metabolism, Female, GPI-Linked Proteins metabolism, Humans, Leukemia, Lymphocytic, Chronic, B-Cell immunology, Lymphocyte Activation, Lymphocytes, Tumor-Infiltrating immunology, Male, Middle Aged, Phenotype, Receptors, Antigen, T-Cell metabolism, Signal Transduction, T-Lymphocytes immunology, Antigens, CD metabolism, Leukemia, Lymphocytic, Chronic, B-Cell metabolism, Lymphocytes, Tumor-Infiltrating metabolism, Receptors, Immunologic metabolism, T-Lymphocytes metabolism
- Abstract
Background: T cell exhaustion compromises antitumor immunity, and a sustained elevation of co-inhibitory receptors is a hallmark of T cell exhaustion in solid tumors. Similarly, upregulation of co-inhibitory receptors has been reported in T cells in hematological cancers such as chronic lymphocytic leukemia (CLL). However, the role of CD160, a glycosylphosphatidylinositol-anchored protein, as one of these co-inhibitory receptors has been contradictory in T cell function. Therefore, we decided to elucidate how CD160 expression and/or co-expression with other co-inhibitory receptors influence T cell effector functions in patients with CLL., Methods: We studied 56 patients with CLL and 25 age-matched and sex-matched healthy controls in this study. The expression of different co-inhibitory receptors was analyzed in T cells obtained from the peripheral blood or the bone marrow. Also, we quantified the properties of extracellular vesicles (EVs) in the plasma of patients with CLL versus healthy controls. Finally, we measured 29 different cytokines, chemokines or other biomarkers in the plasma specimens of patients with CLL and healthy controls., Results: We found that CD160 was the most upregulated co-inhibitory receptor in patients with CLL. Its expression was associated with an exhausted T cell phenotype. CD160
+ CD8+ T cells were highly antigen-experienced/effector T cells, while CD160+ CD4+ T cells were more heterogeneous. In particular, we identified EVs as a source of CD160 in the plasma of patients with CLL that can be taken up by T cells. Moreover, we observed a dominantly proinflammatory cytokine profile in the plasma of patients with CLL. In particular, interleukin-16 (IL-16) was highly elevated and correlated with the advanced clinical stage (Rai). Furthermore, we observed that the incubation of T cells with IL-16 results in the upregulation of CD160., Conclusions: Our study provides a novel insight into the influence of CD160 expression/co-expression with other co-inhibitory receptors in T cell effector functions in patients with CLL. Besides, IL-16-mediated upregulation of CD160 expression in T cells highlights the importance of IL-16/CD160 as potential immunotherapy targets in patients with CLL. Therefore, our findings propose a significant role for CD160 in T cell exhaustion in patients with CLL., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)- Published
- 2021
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16. Gene Methylation and Silencing of WIF1 Is a Frequent Genetic Abnormality in Mantle Cell Lymphoma.
- Author
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Alshareef A, Peters AC, Gélébart P, Chen W, and Lai R
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- Cell Line, Tumor, Cell Proliferation genetics, DNA Methylation genetics, Decitabine pharmacology, Demethylation drug effects, Epigenesis, Genetic genetics, Gene Expression Regulation, Neoplastic genetics, Gene Silencing, Humans, Lymphoma, Mantle-Cell pathology, Wnt Signaling Pathway genetics, Adaptor Proteins, Signal Transducing genetics, Glycogen Synthase Kinase 3 beta genetics, Lymphoma, Mantle-Cell genetics, beta Catenin genetics
- Abstract
We have previously shown that the Wnt canonical pathway (WCP) is constitutively active in most cases of mantle cell lymphoma (MCL). Here, we aimed to elucidate the mechanisms underlying this biochemical deregulation. We hypothesized that gene methylation/silencing of WIF1 (Wnt inhibitory factor-1), a physiologic inhibitor of WCP, contributes to the deregulation of WCP and promotes cell growth in MCL. In support of this hypothesis, we found that the expression of WIF1 was detectable in none of the 4 MCL cell lines, and in only 2 of 5 tumors (40%) examined. Using methylation-specific PCR, we found evidence of gene methylation of WIF1 in 4 of 5 cell lines (80%) and in 24 of 29 (82%) tumors. The addition of the demethylation agent 5-aza-2'-deoxycytidine to Mino and JeKo-1, two WIF1-negative cell lines, restored the expression of WIF1 mRNA in these cells. Gene transfection of WIF1 into JeKo-1 and Mino cells significantly reduced cell growth, and this finding correlated with substantial downregulations of various proteins in WCP, such as β-catenin and pGSK-3β. In conclusion, our results support the concept that gene methylation/silencing of WIF1 is a frequent event in MCL, and this abnormality contributes to the aberrant activation of WCP. These results have provided further evidence that aberrant Wnt signaling is pathogenetically important in MCL and it may represent a potential therapeutic target.
- Published
- 2021
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17. Classic Hodgkin lymphoma post-transplant lymphoproliferative disorders (PTLD) are often preceded by discordant PTLD subtypes.
- Author
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Stubbins RJ, Mabilangan C, Rojas-Vasquez M, Lai RL, Zhu J, Preiksaitis JP, and Peters AC
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- Humans, Risk Factors, Epstein-Barr Virus Infections complications, Epstein-Barr Virus Infections diagnosis, Hodgkin Disease complications, Hodgkin Disease diagnosis, Lymphoproliferative Disorders diagnosis, Lymphoproliferative Disorders etiology, Myeloproliferative Disorders
- Abstract
Classic Hodgkin lymphoma (CHL) is the rarest post-transplant lymphoproliferative disorder (PTLD) subtype. Few cases of patients with metachronous discordant PTLD episodes including CHL-PTLD have been reported, but the incidence of and risk factors for this phenomenon are unknown. Patients with CHL-PTLD were identified from an institutional PTLD database. Of 13 patients identified with CHL-PTLD six (46%) had antecedent non-CHL-PTLD: three had polymorphic PTLD, two monomorphic PTLD, and one nondestructive PTLD. Patients with prior metachronous non-CHL-PTLD were younger at transplant and had a longer latency time to CHL-PTLD post-transplant. The prevalence of EBV seronegativity at transplant was high in both groups, but prolonged high-level EBV DNAemia only occurred in some with metachronous non-CHL-PTLD. In conclusion, patients with CHL-PTLD have metachronous non-CHL-PTLD diagnoses with discordant histology more commonly than previously recognized. Primary EBV infection with chronically elevated EBV viral loads may represent unique risk factors for CHL-PTLD following an initial non-CHL-PTLD event.
- Published
- 2020
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18. Identification of human papillomavirus in oral rinse specimens from women with and without cervical intraepithelial lesions.
- Author
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Nemesio I, Cury F, Longatto-Filho A, Fregnani JH, Musselwhite L, Vazquez F, Peters AC, and Oliveira C
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- Adolescent, Adult, Aged, Aged, 80 and over, Brazil epidemiology, Female, Human papillomavirus 16, Human papillomavirus 18, Humans, Middle Aged, Papillomavirus Infections virology, Sexual Behavior statistics & numerical data, Sexual Partners, Smoking epidemiology, Uterine Cervical Neoplasms virology, Young Adult, Uterine Cervical Dysplasia virology, Mouth virology, Papillomavirus Infections epidemiology, Uterine Cervical Neoplasms epidemiology, Uterine Cervical Dysplasia epidemiology
- Abstract
Objectives: The objective of this study was to evaluate the frequency of human papillomavirus (HPV) in the oral cavity of women with and without abnormal cervical cytology and to determine whether there is an association of oral HPV infection with infection of the cervix or with cervical cancer precursor lesions., Methods: The present study was conducted among 406 women, aged 18-82 years, who attended the Prevention Department of Barretos Cancer Hospital (HCB), Brazil due to a previous altered cervical cytology result. Oral rinse, cervical cytology and biopsy were collected at the same day. The participants also answered a questionnaire about socioeconomic characteristics and risk factors for cervical cancer. Molecular screening for HPV16, HPV18 and 12 other high-risk HPV types was performed on cervical and oral rinse specimens using Cobas 4800 (Roche Molecular Systems, USA)., Results: HPV was detected in the oral rinse of 3.9% of participants. Infection of the oral cavity with a non-HPV16 or 18 type was most frequent (81.2%), followed by HPV16 (18.7%). Infection with HPV in the cervix and oral cavity was present in 11 (2.7%) of participants. There were no differences observed in the smoking status (p value 0.62), mean age of first sexual intercourse (p value 0.25), mean age of the first oral sex (p value 0.90) or mean lifetime number of sexual partners (p value 0.08) between the participants with oral HPV infection or not., Conclusion: The presence of HPV infection in the oral cavity was low in the group of women with abnormal cervical cancer screening findings and a high rate of cervical HPV infection., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2020
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19. Optimal Imaging Guidance During Transcatheter Mitral Valve-in-Valve Replacement in Bioprostheses With Radiolucent Sewing Rings.
- Author
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Gong FF, Peters AC, Malaisrie SC, Davidson CJ, Flaherty JD, Mehlman DJ, Narang A, and Puthumana JJ
- Abstract
Transcatheter mitral valve-in-valve replacement (TMVR) offers a less invasive strategy for managing bioprosthetic mitral valve dysfunction. TMVR positioning is challenging in the setting of a radiolucent bioprosthetic sewing ring. We present 2 cases demonstrating the roles of fluoroscopy and echocardiography in guiding TMVR placement within bioprostheses with radiolucent sewing rings. ( Level of Difficulty: Intermediate. )., (© 2020 The Authors.)
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- 2020
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20. Multimodality imaging to guide transcatheter treatment of severe degenerative tricuspid regurgitation with tricuspid valve-in-ring implantation and paravalvular leak closure.
- Author
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Peters AC, Unger E, Gong FF, El Hangouche N, Puthumana JJ, Thomas JD, Fusari M, Davidson CJ, Ricciardi MJ, Pham D, Flaherty JD, and Narang A
- Subjects
- Cardiac Catheterization, Echocardiography, Transesophageal, Humans, Mitral Valve surgery, Treatment Outcome, Tricuspid Valve diagnostic imaging, Tricuspid Valve surgery, Heart Valve Prosthesis adverse effects, Heart Valve Prosthesis Implantation adverse effects, Tricuspid Valve Insufficiency diagnostic imaging, Tricuspid Valve Insufficiency surgery
- Abstract
Tricuspid valve (TV) degeneration after surgical repair with an annuloplasty ring is problematic as redo operation carries high mortality. This can be addressed with transcatheter therapies to implant a valve within in prior ring (tricuspid valve-in-ring). When an incomplete ring is present, paravalvular leak is commonly encountered after tricuspid valve-in-ring (TViR) implant; however, this can be addressed with paravalvular leak closure devices. Multimodality imaging including cardiac computed tomography and three-dimensional (3D) transesophageal echocardiography (TEE) are important for successful TViR implant. We report a case of tricuspid regurgitation after tricuspid repair with an incomplete annuloplasty ring and subsequent paravalvular leak closure., (© 2020 Wiley Periodicals LLC.)
- Published
- 2020
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21. Three-dimensional echocardiography for the assessment of the tricuspid valve.
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Peters AC, Gong FF, and Rigolin VH
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- Echocardiography, Transesophageal, Humans, Tricuspid Valve diagnostic imaging, Echocardiography, Three-Dimensional, Heart Valve Diseases diagnostic imaging, Tricuspid Valve Insufficiency diagnostic imaging
- Abstract
Tricuspid valve pathology is increasingly recognized as an important contributor to patient morbidity. Accordingly, interest in transcatheter interventions for tricuspid valve disease has continued to grow. Echocardiographic imaging of the tricuspid valve has therefore become an integral component of patient assessment and the essential imaging modality for interventional procedures. The need for improved tricuspid valve imaging has highlighted the variability in tricuspid valve anatomy and the difficulties of using two-dimensional (2D) echocardiography alone to determine the location and type of tricuspid valve disease. Here, three-dimensional (3D) imaging using tools such as biplane imaging, multiplanar reconstruction and live 3D acquisition allow a more accurate and efficient evaluation of the tricuspid valve. The 3D imaging of the tricuspid valve is often focused on transesophageal echocardiography, but the more anterior location of the tricuspid valve also lends itself to assessment with transthoracic echocardiography. In this review, we will examine how 3D imaging can complement and enhance the information obtained from 2D echocardiography, and present novel applications for the quantitation of valvular disease and its utility in intraprocedural imaging., (© 2020 Wiley Periodicals, Inc.)
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- 2020
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22. Failure of rituximab is associated with a poor outcome in diffuse large B cell lymphoma-type post-transplant lymphoproliferative disorder.
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Jain MD, Lam R, Liu Z, Stubbins RJ, Kahlon A, Kansara R, Goswami R, Humar A, Prica A, Sehn LH, Slack GW, Crump M, Savage KJ, Peters AC, and Kuruvilla J
- Subjects
- Adult, Aged, Antineoplastic Combined Chemotherapy Protocols administration & dosage, Antineoplastic Combined Chemotherapy Protocols adverse effects, Cyclophosphamide administration & dosage, Cyclophosphamide adverse effects, Disease-Free Survival, Doxorubicin administration & dosage, Doxorubicin adverse effects, Female, Humans, Male, Middle Aged, Prednisone administration & dosage, Prednisone adverse effects, Retrospective Studies, Survival Rate, Vincristine administration & dosage, Vincristine adverse effects, Lymphoma, Large B-Cell, Diffuse drug therapy, Lymphoma, Large B-Cell, Diffuse etiology, Lymphoma, Large B-Cell, Diffuse mortality, Organ Transplantation adverse effects, Postoperative Complications drug therapy, Postoperative Complications etiology, Postoperative Complications mortality, Rituximab administration & dosage, Rituximab adverse effects
- Abstract
Post-transplant lymphoproliferative disorder (PTLD) may arise after solid organ transplantation, and the most common subtype resembles diffuse large B cell lymphoma (DLBCL). In DLBCL-type PTLD, the anti-CD20 antibody rituximab (R) may be combined with chemotherapy (R-CHOP) or use a strategy (R-primary; similar to the PTLD-1 clinical trial) consisting of induction with four weekly doses of R-alone, without any chemotherapy or sequential R-CHOP follow-up. Here we report on a multicentre retrospective cohort of solid organ transplant patients with DLBCL-type PTLD that were treated with R. In 168 adults, two-year overall survival (OS) was 63·7% [95% CI (confidence interval) 56·6-71·7%]. No difference in OS was observed, whether patients were treated with R-CHOP versus the R-primary strategy. In the 109 patients treated with R-primary, multivariate analysis found that baseline IPI score and the response to R-induction predicted OS. Patients who responded to R-induction had durable remissions without the addition of chemotherapy. Conversely, of the 46 patients who had stable or progressive disease after R-induction (R-failure), those who received R-CHOP had an only marginally improved outcome, with a two-year OS of 45% (23·1-65·3%) vs. no R-CHOP at 32% (14·7-49·8%). In real-world patients, R-failure and high IPI scores predict a poor outcome in DLBCL-type PTLD., (© 2020 British Society for Haematology and John Wiley & Sons Ltd.)
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- 2020
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23. Epstein-Barr virus associated smooth muscle tumors in solid organ transplant recipients: Incidence over 31 years at a single institution and review of the literature.
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Stubbins RJ, Alami Laroussi N, Peters AC, Urschel S, Dicke F, Lai RL, Zhu J, Mabilangan C, and Preiksaitis JK
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- Age Factors, Epstein-Barr Virus Infections virology, Female, Graft Rejection prevention & control, Humans, Immunocompromised Host, Immunosuppressive Agents adverse effects, Incidence, Infant, Postoperative Complications virology, Smooth Muscle Tumor virology, Transplant Recipients, Epstein-Barr Virus Infections epidemiology, Herpesvirus 4, Human isolation & purification, Organ Transplantation adverse effects, Postoperative Complications epidemiology, Smooth Muscle Tumor epidemiology
- Abstract
Introduction: Epstein-Barr virus (EBV) associated smooth muscle tumors (EBV-SMT) are a rare complication of solid organ transplantation (SOT). Incidence data related to this EBV-SMT are limited. EBV DNA is universally present in these tumors. How these cells get infected with EBV, whether this is a result of primary EBV infection vs reactivation, and how persistent active EBV infection post-transplant influences EBV-SMT pathogenesis remains unknown., Methods: Among 5006 SOT recipients (474 pediatric, 4532 adult) receiving SOT at our center between Jan 1984 and Dec 2015, three cases of post-transplant EBV-SMT were identified., Results: All cases were pediatric heart transplants who were EBV seronegative prior to transplant, and experienced primary EBV infection with persistently elevated EBV viral loads, despite antiviral therapy. Two are deceased at 3.2 and 0.9 years post-diagnosis, while one remains alive 6.2 years post diagnosis. The overall local incidence of post-transplant EBV-SMT at our institution was 0.7 (95% CI, 0.2-1.7) per 1000 patient years, and 2.6 (95% CI, 0.6-6.7) per 1000 patient years in pediatric heart transplants. A literature review identified 36 pediatric and 51 adult cases of post-transplant EBV-SMT., Conclusions: We hypothesize that pre-transplant EBV seronegativity, followed by primary EBV infection and persistently high EBV viral loads, represents a unique risk factor for post-transplant EBV-SMT. Pediatric heart transplant recipients were found to be disproportionately affected by post-transplant EBV-SMT at our institution., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
- Published
- 2019
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24. The Adverse Consequences of Initial Watchful Waiting for Patients With Follicular Lymphoma.
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Davies GA, Ghosh S, Oh DH, Manna M, Peters AC, Stewart CA, and Stewart DA
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- Adolescent, Adult, Aged, Cell Transformation, Neoplastic, Disease Management, Disease Progression, Female, Follow-Up Studies, Humans, Incidence, Lymphoma, Follicular epidemiology, Lymphoma, Follicular etiology, Male, Middle Aged, Neoplasm Grading, Organ Dysfunction Scores, Proportional Hazards Models, Survival Analysis, Tumor Burden, Watchful Waiting, Young Adult, Lymphoma, Follicular diagnosis
- Abstract
Background: Patients with low tumor burden follicular lymphoma (FL) are commonly managed with watchful waiting (WW). The incidence of organ dysfunction and/or transformation at disease progression, and subsequent impact on outcomes is poorly understood., Patients and Methods: Patients managed with WW during 1994 to 2011 were identified through the Alberta Lymphoma Database. Individuals receiving immediate rituximab (R)-chemotherapy were identified as a comparator group to those on WW who received R-chemotherapy at progression. Endpoints included transformation, organ dysfunction, time to progression, time to next treatment, progression-free survival (PFS) after chemotherapy, and overall survival (OS)., Results: We identified 238 patients managed with WW (28.9% of registry patients) during this 17-year period. The median follow up was 8.2 years. At a median of 29.9 months, 58 (24.4%) of these patients developed organ dysfunction and/or transformation. Of 169 (71%) patients who required therapy, 10-year OS was inferior for those with transformation (hazard ratio, 2.88; P = .002) and organ dysfunction (hazard ratio, 2.10; P = .028). PFS after R-chemotherapy and OS in patients without organ dysfunction and/or transformation was not affected by the initial WW period, compared with immediate R-chemotherapy. WW resulted in increased high risk FL International Prognostic Index scores at initiation of R-chemotherapy (45% vs. 20%), and more frequent transformation at progression (5-year risk, 17.8% vs. 3.5%; P < .001). Baseline characteristics did not predict organ dysfunction., Conclusion: Patients with FL accepting initial WW should be aware of the 1 in 4 risk of organ dysfunction and/or transformation, and subsequent inferior OS. Physicians should consider surveillance for progression to consider early therapy., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
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25. The Changing Epidemiology of Posttransplant Lymphoproliferative Disorder in Adult Solid Organ Transplant Recipients Over 30 Years: A Single-center Experience.
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Peters AC, Akinwumi MS, Cervera C, Mabilangan C, Ghosh S, Lai R, Iafolla M, Doucette K, and Preiksaitis JK
- Subjects
- Adolescent, Adult, Alberta epidemiology, Antiviral Agents administration & dosage, Epstein-Barr Virus Infections diagnosis, Epstein-Barr Virus Infections prevention & control, Epstein-Barr Virus Infections virology, Female, Humans, Immunosuppressive Agents adverse effects, Incidence, Lymphoproliferative Disorders diagnosis, Lymphoproliferative Disorders prevention & control, Lymphoproliferative Disorders virology, Male, Middle Aged, Opportunistic Infections diagnosis, Opportunistic Infections prevention & control, Opportunistic Infections virology, Protective Factors, Retrospective Studies, Risk Assessment, Risk Factors, Time Factors, Treatment Outcome, Viral Load, Young Adult, Epstein-Barr Virus Infections epidemiology, Lymphoproliferative Disorders epidemiology, Opportunistic Infections epidemiology, Organ Transplantation adverse effects
- Abstract
Background: Posttransplant lymphoproliferative disorders (PTLD) are a complication of solid organ transplantation (SOT) associated with Epstein-Barr virus (EBV)., Methods: We analyzed the incidence of and risk factors for PTLD among adult SOT recipients at our center over 30 years (1984-2013). We also compared PTLD incidence before and after a prevention strategy of EBV viral load monitoring in EBV serology mismatched patients was adapted in 2001 (ie, transplant era 1 [1983-2001] vs era 2 [2002-2013])., Results: Among 4171 SOT patients, 109 developed PTLD. Cumulative incidence at 1, 10, and 20 years posttransplant was 0.95, 2.3, and 3.5 per 100 person-years, respectively. Beyond the first year peak of almost exclusively EBV-positive PTLD, a lower incidence of PTLD, predominantly EBV negative, persisted for 20 years. Thoracic transplant (hazard ratio [HR], 2.1; P = 0.007) and negative EBV serology (HR, 7.7; P < 0.001) were independent risk factors for PTLD on multivariate Cox regression analysis. EBV seronegativity significantly increased risk of early (HR, 18.5) and EBV-positive PTLD (HR, 14.2), as well as late (HR, 4.9) and EBV-negative PTLD (HR, 3.6) on univariate analyses. Risk of early PTLD was significantly reduced in the recent transplant era (0.8% era 2 vs 1.9% era 1 at 5 years, P = 0.002); this reduction was seen in recent era EBV seropositive (P = 0.035 at 5 years) but not seronegative recipients (P = 0.90 year 5), suggesting lack of impact of viral load monitoring., Conclusions: Adult SOT recipients face a prolonged risk of late PTLD, whereas risk of early PTLD may have declined in recent years.
- Published
- 2018
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26. Constitutive Activation of STAT3 in Myeloma Cells Cultured in a Three-Dimensional, Reconstructed Bone Marrow Model.
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Huang YH, Molavi O, Alshareef A, Haque M, Wang Q, Chu MP, Venner CP, Sandhu I, Peters AC, Lavasanifar A, and Lai R
- Abstract
Malignant cells cultured in three-dimensional (3D) models have been found to be phenotypically and biochemically different from their counterparts cultured conventionally. Since most of these studies employed solid tumor types, how 3D culture affects multiple myeloma (MM) cells is not well understood. Here, we compared MM cells (U266 and RPMI8226) in a 3D culture model with those in conventional culture. While the conventionally cultured cells were present in single cells or small clusters, MM-3D cells grew in large spheroids. We discovered that STAT3 was the pathway that was more activated in 3D in both cell lines. The active form of STAT3 (phospho-STAT3 or pSTAT3), which was absent in MM cells cultured conventionally, became detectable after 1⁻2 days in 3D culture. This elevated pSTAT3 level was dependent on the 3D environment, since it disappeared after transferring to conventional culture. STAT3 inhibition using a pharmacological agent, Stattic, significantly decreased the cell viability of MM cells and sensitized them to bortezomib in 3D culture. Using an oligonucleotide array, we found that 3D culture significantly increased the expression of several known STAT3 downstream genes implicated in oncogenesis. Since most primary MM tumors are naturally STAT3-active, studies of MM in 3D culture can generate results that are more representative of the disease.
- Published
- 2018
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27. The role of the law in reducing tuberculosis transmission in Botswana, South Africa and Zambia.
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Verani AR, Emerson CN, Lederer P, Lipke G, Kapata N, Lanje S, Peters AC, Zulu I, Marston BJ, and Miller B
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- Africa, Southern epidemiology, Health Policy, Humans, Tuberculosis epidemiology, Public Health legislation & jurisprudence, Tuberculosis prevention & control, Tuberculosis transmission
- Abstract
Objective: To determine whether laws and regulations in Botswana, South Africa and Zambia - three countries with a high tuberculosis and HIV infection burden - address elements of the World Health Organization (WHO) policy on tuberculosis infection control., Methods: An online desk review of laws and regulations that address six selected elements of the WHO policy on tuberculosis infection control in the three countries was conducted in November 2015 using publicly available domestic legal databases. The six elements covered: (i) national policy and legal framework; (ii) health facility design, construction and use; (iii) tuberculosis disease surveillance among health workers; (iv) patients' and health workers' rights; (v) monitoring of infection control measures; and (vi) relevant research., Findings: The six elements were found to be adequately addressed in the three countries' laws and regulations. In all three, tuberculosis case-reporting is required, as is tuberculosis surveillance among health workers. Each country's legal and regulatory framework also addresses the need to respect individuals' rights and privacy while safeguarding public health. These laws and regulations create a strong foundation for tuberculosis infection control. Although the legal and regulatory frameworks thoroughly address tuberculosis infection control, their dissemination, implementation and enforcement were not assessed, nor was their impact on public health., Conclusion: Laws and regulations in Botswana, South Africa and Zambia address all six selected elements of the WHO policy on tuberculosis infection control. However, the lack of data on their implementation is a limitation. Future research should assess the implementation and public health impact of laws and regulations.
- Published
- 2016
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28. Voting rights for Associates (trainees) and Affiliates at RANZCP annual general meeting and in Board elections.
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Peters AC and Hain L
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- Australia, Humans, New Zealand, Governing Board organization & administration, Mental Health education, Psychiatry education, Schools, Medical
- Published
- 2015
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29. Lymphoproliferative disorders in inflammatory bowel disease patients on immunosuppression: Lessons from other inflammatory disorders.
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Lam GY, Halloran BP, Peters AC, and Fedorak RN
- Abstract
Immunosuppressive agents, such as thiopurines, methotrexate, and biologics, have revolutionized the treatment of inflammatory bowel disease (IBD). However, a number of case reports, case control studies and retrospective studies over the last decade have identified a concerning link between immunosuppression and lymphoproliferative disorders (LPDs), the oncological phenomenon whereby lymphocytes divide uncontrollably. These LPDs have been associated with Epstein-Barr virus (EBV) infection in which the virus provides the impetus for malignant transformation while immunosuppression hampers the immune system's ability to detect and clear these malignant cells. As such, the use of immunosuppressive agents may come at the cost of increased risk of developing LPD. While little is known about the LPD risk in IBD, more is known about immunosuppression in the post-transplantation setting and the development of EBV associated post-transplantation lymphoproliferative disorders (PTLD). In review of the PTLD literature, evidence is available to demonstrate that certain immune suppressants such as cyclosporine and T-lymphocyte modulators in particular are associated with an increased risk of PTLD development. As well, high doses of immunosuppressive agents and multiple immunosuppressive agent use are also linked to increased PTLD development. Here, we discuss these findings in context of IBD and what future studies can be taken to understand and reduce the risk of EBV-associated LPD development from immunosuppression use in IBD.
- Published
- 2015
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30. One night of partial sleep deprivation affects habituation of hypothalamus and skin conductance responses.
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Peters AC, Blechert J, Sämann PG, Eidner I, Czisch M, and Spoormaker VI
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- Adult, Anxiety physiopathology, Association Learning, Conditioning, Classical, Fear, Female, Humans, Male, Galvanic Skin Response, Habituation, Psychophysiologic, Hypothalamus physiopathology, Sleep Deprivation physiopathology
- Abstract
Sleep disturbances are prevalent in clinical anxiety, but it remains unclear whether they are cause and/or consequence of this condition. Fear conditioning constitutes a valid laboratory model for the acquisition of normal and pathological anxiety. To explore the relationship between disturbed sleep and anxiety in more detail, the present study evaluated the effect of partial sleep deprivation (SD) on fear conditioning in healthy individuals. The neural correlates of 1) nonassociative learning and physiological processing and 2) associative learning (differential fear conditioning) were addressed. Measurements entailed simultaneous functional MRI, EEG, skin conductance response (SCR), and pulse recordings. Regarding nonassociative learning, partial SD resulted in a generalized failure to habituate during fear conditioning, as evidenced by reduced habituation of SCR and hypothalamus responses to all stimuli. Furthermore, SCR and hypothalamus activity were correlated, supporting their functional relationship. Regarding associative learning, effects of partial SD on the acquisition of conditioned fear were weaker and did not reach statistical significance. The hypothalamus plays an integral role in the regulation of sleep and autonomic arousal. Thus sleep disturbances may play a causal role in the development of normal and possibly pathological fear by increasing the susceptibility of the sympathetic nervous system to stressful experiences., (Copyright © 2014 the American Physiological Society.)
- Published
- 2014
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31. The Effect of Articular Reduction After Fractures on Posttraumatic Degenerative Arthritis: A Critical Analysis Review.
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Peters AC, Lafferty PM, Jacobson AR, and Cole PA
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- 2013
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32. Durable event-free survival following autologous stem cell transplant for relapsed or refractory follicular lymphoma: positive impact of recent rituximab exposure and low-risk Follicular Lymphoma International Prognostic Index score.
- Author
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Peters AC, Duan Q, Russell JA, Duggan P, Owen C, and Stewart DA
- Subjects
- Adult, Aged, Antibodies, Monoclonal, Murine-Derived administration & dosage, Antibodies, Monoclonal, Murine-Derived adverse effects, Antineoplastic Combined Chemotherapy Protocols adverse effects, Combined Modality Therapy, Disease-Free Survival, Dose-Response Relationship, Drug, Drug Resistance, Neoplasm, Female, Humans, Infections etiology, International Cooperation, Male, Middle Aged, Multivariate Analysis, Neutropenia etiology, Prognosis, Recurrence, Retrospective Studies, Rituximab, Stem Cell Transplantation adverse effects, Transplantation, Autologous, Treatment Outcome, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Lymphoma, Follicular drug therapy, Lymphoma, Follicular surgery, Stem Cell Transplantation methods
- Abstract
Published studies have provided conflicting results regarding the curative potential of high dose chemotherapy and autologous stem cell transplant (HDT/ASCT) for follicular lymphoma (FL). Our objectives were to evaluate the long-term event-free (EFS) and overall (OS) survival rates following ASCT for FL, and to identify predictors of improved outcome. We conducted a retrospective analysis of the first 100 consecutive patients with relapsed or refractory FL treated with HDT/ASCT in Calgary from 1993 to 2008. With a median follow-up of 65 months (range 16-178) post-ASCT, 5-year EFS and OS rates were 56% (95% confidence interval [CI] 46-66%) and 70% (95% CI 61-79%), respectively. A plateau on the EFS curve is evident starting 6 years post-ASCT. Also, the EFS post-ASCT was markedly longer than the 12-month median EFS from last therapy prior to ASCT (p < 0.0001). Failure of rituximab pre-ASCT was not associated with EFS or OS. Severe toxicities included two early treatment-related deaths, and four late deaths from secondary leukemia. Independent predictors of EFS and OS in multivariate analysis were rituximab therapy within 6 months of ASCT, chemosensitivity and FLIPI (FL International Prognostic Index) score 0-1. In conclusion, our data suggest that over 50% of patients with relapsed/refractory FL who have failed 1-2 prior chemotherapy regimens achieve long-term EFS following HDT/ASCT.
- Published
- 2011
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33. Long term outcome of benign childhood epilepsy with centrotemporal spikes: Dutch Study of Epilepsy in Childhood.
- Author
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Callenbach PM, Bouma PA, Geerts AT, Arts WF, Stroink H, Peeters EA, van Donselaar CA, Peters AC, and Brouwer OF
- Subjects
- Age of Onset, Child, Child, Preschool, Female, Follow-Up Studies, Humans, Infant, Male, Netherlands, Predictive Value of Tests, Prognosis, Remission Induction, Surveys and Questionnaires, Treatment Outcome, Anticonvulsants therapeutic use, Developmental Disabilities etiology, Epilepsy, Rolandic complications, Epilepsy, Rolandic drug therapy, Epilepsy, Rolandic physiopathology
- Abstract
Purpose: To determine long-term outcome in a cohort of children with newly diagnosed benign childhood epilepsy with centrotemporal spikes (BECTS)., Methods: 29 children with BECTS were included in the Dutch Study of Epilepsy in Childhood. Each child was followed for 5 years, and subsequently contacted 12-17 years after enrolment to complete a structured questionnaire. Twenty children had typical BECTS, nine had atypical BECTS (age at onset <4 years, developmental delay or learning difficulties at inclusion, other seizure types, atypical EEG abnormalities)., Results: Mean age at onset of epilepsy was 8.0 years with slight male preponderance. Most common seizure-types before enrolment were generalized tonic-clonic seizures (GTCS) and simple partial seizures; in 86% of the children seizures occurred during sleep. After 12-17 years, 96% had a terminal remission (TR(F)) of more than 5 years and 89% of more than 10 years. Mean duration of epilepsy was 2.7 years; mean age at reaching TR(F) was 10.6 years. Many children (63%) had experienced one or more (secondary) GTCS. Antiepileptic drugs were used by 79% of the children with a mean duration of 3.0 years. None of the children seemed to have developed learning problems or an arrest of cognitive development during follow-up. No significant differences were observed in patient characteristics or outcome between children with typical BECTS and children with atypical BECTS., Conclusions: All children in our cohort, both those with typical and atypical BECTS, had a very good prognosis with high remission rates after 12-17 years. None of the predictive factors for disease course and outcome observed in earlier studies (other seizure types, age at onset, multiple seizures at onset) were prognostic in our cohort., (Copyright © 2010 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2010
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34. Biological and clinical significance of GSK-3beta in mantle cell lymphoma--an immunohistochemical study.
- Author
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Chung R, Peters AC, Armanious H, Anand M, Gelebart P, and Lai R
- Subjects
- Adult, Aged, Aged, 80 and over, Cyclin D1 metabolism, Female, Glycogen Synthase Kinase 3 beta, Humans, Lymphoma, Mantle-Cell mortality, Male, Middle Aged, Prognosis, Regression Analysis, Retrospective Studies, Survival Rate, beta Catenin metabolism, Glycogen Synthase Kinase 3 metabolism, Lymphoma, Mantle-Cell metabolism, Lymphoma, Mantle-Cell pathology
- Abstract
GSK-3beta, a biologically important signalling protein, is regulated by the Wnt canonical and the PI3K/Akt pathways. We recently reported that mantle cell lymphoma (MCL) frequently shows evidence of GSK-3beta inactivation, since GSK-3beta is phoshorylated at its functionally critical serine 9 residue in all MCL cell lines and the majority of MCL tumors examined. To further assess the clinical and biological significance of GSK-3beta inactivation in MCL, we employed immunohistochemistry to assess the expression of the phosphorylated/inactive form of GSK-3beta (pGSK-3beta) in 83 paraffin-embedded tumors, and correlated its expression with various biological and clinical parameters. Dichotomizing pGSK-3beta into 2 groups produced twenty-seven (32.5%) tumors assessed as negative and fifty-six (67.5%) as positive. Positive pGSK-3beta expression correlated significantly with positive nuclear expression of beta-catenin and high expression of cyclin D1 (p = 0.0025, 0.0032 Fisher's exact, respectively), both of which have been previously shown to be regulated by GSK-3beta regarding their expression levels and/or sub cellular localization in-vitro. However, no significant correlation was found between pGSK-3beta and Ki67. Of the clinical parameters, continuous pGSK-3beta status had a significant correlation with absolute lymphocyte count in blood (p = 0.0011, Spearman) and negative pGSK-3beta expression was significantly correlated with a longer overall survival (p= 0.045, HR = 1.89), but not with age at diagnosis, clinical stage or the international prognostic index. To conclude, our results support the concept that GSK-3beta inactivation, found in approximately two-thirds of MCL tumors, is biologically and clinically important in MCL.
- Published
- 2010
35. Long-term outcome of childhood absence epilepsy: Dutch Study of Epilepsy in Childhood.
- Author
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Callenbach PM, Bouma PA, Geerts AT, Arts WF, Stroink H, Peeters EA, van Donselaar CA, Peters AC, and Brouwer OF
- Subjects
- Adolescent, Age Factors, Child, Child, Preschool, Epilepsy, Absence drug therapy, Female, Humans, Infant, Infant, Newborn, Longitudinal Studies, Male, Netherlands epidemiology, Recurrence, Retrospective Studies, Electroencephalography methods, Epilepsy, Absence epidemiology, Epilepsy, Absence physiopathology
- Abstract
Summary: We determined long-term outcome and the predictive value of baseline and EEG characteristics on seizure activity evolution in 47 children with newly diagnosed childhood absence epilepsy (CAE) included in the Dutch Study of Epilepsy in Childhood. All children were followed for 12-17 years. The children were subdivided in three groups for the analyses: those becoming seizure-free (I) within 1 month after enrolment; (II) 1-6 months after enrolment; and (III) more than 6 months after enrolment or having seizures continuing during follow-up. No significant differences were observed between groups in sex, age at onset, occurrence of febrile seizures, and positive first-degree family history for epilepsy. All groups had high remission rates after 12-17 years. Significantly more relapses occurred in group III than in group I. Total duration of epilepsy and mean age at final remission were 3.9 and 9.5 years, respectively, being significantly longer and higher in group III than in groups I and II. In all groups only a small number of children (total 13%) developed generalized tonic-clonic seizures. In conclusion, our children with CAE had an overall good prognosis with few children (7%) still having seizures after 12-17 years. Remission rate in children with CAE cannot be predicted on the basis of baseline and EEG characteristics. The early clinical course (i.e. the first 6 months) has some predictive value with respect to the total duration of absence epilepsy.
- Published
- 2009
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36. A quarter century of the analysis of verbal behavior: an analysis of impact.
- Author
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Petursdottir AI, Peterson SP, and Peters AC
- Abstract
The Analysis of Verbal Behavior (TAVB) has been published since 1982, and during this time, interest in verbal behavior research appears to have increased substantially within behavior analysis. The purpose of the present analysis was to assess the influence of TAVB on the field by (a) counting citations of TAVB articles in the Journal of the Experimental Analysis of Behavior (JEAB) and the Journal of Applied Behavior Analysis (JABA) from 1983 through 2007, (b) examining which other journals cite TAVB, and (c) calculating impact-factor estimates for 2003 through 2007. Citations of TAVB articles began to appear in JEAB and JABA in the late 1980s to early 1990s, and by the end of 2007, almost a third of all articles published in TAVB had been cited in either JEAB or JABA. Other journals that cite TAVB include The Behavior Analyst and The Psychological Record. The estimated impact factor ranged from 0.267 to 0.600. Strategies for increasing the impact of TAVB are discussed.
- Published
- 2009
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37. Constitutive activation of the Wnt canonical pathway in mantle cell lymphoma.
- Author
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Gelebart P, Anand M, Armanious H, Peters AC, Dien Bard J, Amin HM, and Lai R
- Subjects
- Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Glycogen Synthase Kinase 3 genetics, Humans, Lymphoma, Mantle-Cell etiology, Tumor Cells, Cultured, Wnt Proteins genetics, Wnt3 Protein, beta Catenin genetics, Glycogen Synthase Kinase 3 metabolism, Lymphoma, Mantle-Cell metabolism, Signal Transduction genetics, Wnt Proteins metabolism, beta Catenin metabolism
- Abstract
Aberrations of the Wnt canonical pathway (WCP) are known to contribute to the pathogenesis of various types of cancer. We hypothesize that these defects may exist in mantle cell lymphoma (MCL). Both the upstream and downstream aspects of WCP were examined in MCL cell lines and tumors. Using WCP-specific oligonucleotide arrays, we found that MCL highly and consistently expressed Wnt3 and Wnt10. beta-catenin, a transcriptional factor that is a downstream target of WCP, is localized to the nucleus and transcriptionally active in all 3 MCL cell lines examined. By immunohistochemistry, 33 (52%) of 64 MCL tumors showed nuclear localization of beta-catenin, which significantly correlated with the expression of the phosphorylated/inactive form of GSK3beta (p-GSK3beta; P = .011, Fisher). GSK3beta inactivation is directly linked to WCP stimulation, since addition of recombinant sFRP proteins (a naturally occurring decoy for the Wnt receptors) resulted in a significant decrease in p-GSK3beta. Down-regulation of DvL-2 (an upstream signaling protein in WCP) by siRNA or selective inhibition of beta-catenin using quercetin significantly decreased cell growth in MCL cell lines. To conclude, WCP is constitutively activated in a subset of MCL and it appears to promote tumorigenesis in MCL.
- Published
- 2008
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38. Validation of two prognostic models predicting outcome at two years after diagnosis in a new cohort of children with epilepsy: the Dutch Study of Epilepsy in Childhood.
- Author
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Geerts AT, Arts WF, Brouwer OF, Peters AC, Peeters EA, Stroink H, and van Donselaar CA
- Subjects
- Adolescent, Child, Child, Preschool, Cohort Studies, Electroencephalography statistics & numerical data, Epilepsy epidemiology, Female, Follow-Up Studies, Hospitalization statistics & numerical data, Humans, Infant, Male, Models, Statistical, Netherlands epidemiology, Predictive Value of Tests, Prognosis, ROC Curve, Referral and Consultation, Reproducibility of Results, Treatment Outcome, Epilepsy diagnosis, Outcome Assessment, Health Care statistics & numerical data
- Abstract
Purpose: To validate two prognostic models for childhood-onset epilepsy designed to predict a terminal remission of <6 months at 2 years after diagnosis in children referred to the hospital., Methods: A hospital-based cohort of children with newly diagnosed epilepsy was recruited and followed up for 2 years to validate previously developed models. One model was based on variables collected at intake, and the other was based on intake variables plus variables collected during the first 6 months of follow-up. The accuracy of both models was estimated by measuring the area under the receiver-operant-characteristic curves (ROC area)., Results: The ROC area of the model developed with intake variables was 0.69 [95% confidence interval (CI), 0.64-0.74] for the original cohort and 0.62 (95% CI, 0.55-0.69) for the validation cohort. The best combination of sensitivity and specificity for the original cohort was 61.6% and 69.1%, whereas it was 60.0% and 61.4% for the validation cohort. For the model with intake and 6-month variables combined, the ROC area was 0.78 (95% CI, 0.73-0.82) for the original cohort and 0.71 (95% CI, 0.64-0.78) for the validation cohort. The sensitivity and specificity were 72.6% and 73.1%, respectively, for the original cohort and 67.4% and 60.2%, respectively, for the validation cohort., Conclusions: Although both models predict outcome better than chance, they are insufficiently accurate to be of practical value. Both models performed marginally less well with the validation cohort than with the original cohort, but in both instances, the model based on intake and 6-month variables was more accurate.
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- 2006
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39. Effect of educational outreach to nurses on tuberculosis case detection and primary care of respiratory illness: pragmatic cluster randomised controlled trial.
- Author
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Fairall LR, Zwarenstein M, Bateman ED, Bachmann M, Lombard C, Majara BP, Joubert G, English RG, Bheekie A, van Rensburg D, Mayers P, Peters AC, and Chapman RD
- Subjects
- Adolescent, Adrenal Cortex Hormones administration & dosage, Adult, Aged, Anti-Bacterial Agents therapeutic use, Case Management, Cluster Analysis, Female, Humans, Lung Diseases, Obstructive diagnosis, Lung Diseases, Obstructive drug therapy, Lung Diseases, Obstructive nursing, Male, Middle Aged, Primary Health Care, Prognosis, Referral and Consultation statistics & numerical data, Respiration Disorders drug therapy, South Africa, Tuberculosis, Pulmonary diagnosis, Tuberculosis, Pulmonary drug therapy, Education, Nursing methods, Nurse Practitioners education, Respiration Disorders nursing, Tuberculosis, Pulmonary nursing
- Abstract
Objectives: To develop and implement an educational outreach programme for the integrated case management of priority respiratory diseases (practical approach to lung health in South Africa; PALSA) and to evaluate its effects on respiratory care and detection of tuberculosis among adults attending primary care clinics., Design: Pragmatic cluster randomised controlled trial, with clinics as the unit of randomisation., Setting: 40 primary care clinics, staffed by nurse practitioners, in the Free State province, South Africa., Participants: 1999 patients aged 15 or over with cough or difficult breathing (1000 in intervention clinics, 999 in control clinics)., Intervention: Between two and six educational outreach sessions delivered to nurse practitioners by usual trainers from the health department. The emphasis was on key messages drawn from the customised clinical practice guideline for the outreach programme, with illustrative support materials., Main Outcome Measures: Sputum screening for tuberculosis, tuberculosis case detection, inhaled corticosteroid prescriptions for obstructive lung disease, and antibiotic prescriptions for respiratory tract infections., Results: All clinics and almost all patients (92.8%, 1856/1999) completed the trial. Although sputum testing for tuberculosis was similar between the groups (22.6% in outreach group v 19.3% in control group; odds ratio 1.22, 95% confidence interval 0.83 to 1.80), the case detection of tuberculosis was higher in the outreach group (6.4% v 3.8%; 1.72, 1.04 to 2.85). Prescriptions for inhaled corticosteroids were also higher (13.7% v 7.7%; 1.90, 1.14 to 3.18) but the number of antibiotic prescriptions was similar (39.7% v 39.4%; 1.01, 0.74 to 1.38)., Conclusions: Combining educational outreach with integrated case management provides a promising model for improving quality of care and control of priority respiratory diseases, without extra staff, in resource poor settings., Trial Registration: Current controlled trials ISRCTN13438073.
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- 2005
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40. Three to four years after diagnosis: cognition and behaviour in children with 'epilepsy only'. A prospective, controlled study.
- Author
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Oostrom KJ, van Teeseling H, Smeets-Schouten A, Peters AC, and Jennekens-Schinkel A
- Subjects
- Adaptation, Psychological, Adolescent, Case-Control Studies, Chi-Square Distribution, Child, Female, Follow-Up Studies, Humans, Male, Neuropsychological Tests, Parenting, Prospective Studies, Schools, Time Factors, Child Behavior, Cognition, Epilepsy psychology
- Abstract
A 3.5-year follow-up study of cognition and behaviour in 42 children with newly diagnosed idiopathic or cryptogenic epilepsy ('epilepsy only') attending mainstream education and 30 healthy gender-matched classmate controls was carried out to identify differences between groups, to detect factors that contribute to the difference and its change over time, and to establish the proportion of poorly performing children. The neuropsychological battery covered the major domains of cognition, mental and motor speed and academic language skills. Children were tested at the time of diagnosis (before any anti-epileptic drug treatment started) and 3, 12 and approximately 42 months later. Parents and teachers completed behaviour checklists, for which the scoring was adapted to prevent any influence of epilepsy-related ambiguity. Based on parental interviews at the time of diagnosis, children with epilepsy were categorized as having longstanding behavioural and/or learning problems, as belonging to a troubled family, as being exposed to 'off-balance' parenting starting at the time of epilepsy onset and/or as reacting maladaptively to the changes in relation to the onset of epilepsy. Throughout follow-up, the group of children with epilepsy only performed less well than healthy classmates on measures of learning, memory span for words, attention and behaviour. After controlling for school delay, proactive interference (number of responses to the same images as in the learning trials, but now presented in reordered locations) was the only remaining variable that distinguished the group of children with epilepsy only. Group-wise, no changes in cognitive and behavioural differences over time were found, but instability in individual performances appeared to characterize children with epilepsy only. Rather than intrinsically epilepsy-related variables, such as idiopathic versus cryptogenic aetiology, seizure control or anti-epileptic drug treatment, the child's prediagnostic learning and behavioural histories and the parents' ability to continue their habitual parenting in the face of the diagnosis of epilepsy only were shown by both group-wise and case-by-case analyses to be important for understanding the cognitive and behavioural functioning of the children with epilepsy only.
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- 2005
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41. Four-year outcome after early withdrawal of antiepileptic drugs in childhood epilepsy.
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Geerts AT, Niermeijer JM, Peters AC, Arts WF, Brouwer OF, Stroink H, Peeters EA, and van Donselaar CA
- Subjects
- Adolescent, Anticonvulsants administration & dosage, Brain drug effects, Brain physiopathology, Child, Child, Preschool, Drug Administration Schedule, Electroencephalography, Epilepsy prevention & control, Female, Follow-Up Studies, Humans, Infant, Male, Models, Neurological, Predictive Value of Tests, Prognosis, Remission Induction, Secondary Prevention, Time, Time Factors, Withholding Treatment trends, Anticonvulsants adverse effects, Epilepsy chemically induced, Epilepsy drug therapy, Substance Withdrawal Syndrome diagnosis, Withholding Treatment statistics & numerical data
- Abstract
Four-year follow-up of children with epilepsy included in a randomized trial of early withdrawal of antiepileptic drugs showed that 51% achieved a terminal remission of at least 2 years without medication and 21% with medication; 15% had seizures during the fourth year. Early medication withdrawal is not recommended as standard practice in children with a rapid response to medication. The authors developed a model to predict outcome if withdrawal is considered.
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- 2005
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42. Course and prognosis of childhood epilepsy: 5-year follow-up of the Dutch study of epilepsy in childhood.
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Arts WF, Brouwer OF, Peters AC, Stroink H, Peeters EA, Schmitz PI, van Donselaar CA, and Geerts AT
- Subjects
- Adolescent, Analysis of Variance, Anticonvulsants therapeutic use, Child, Child, Preschool, Epilepsy drug therapy, Female, Follow-Up Studies, Humans, Infant, Male, Models, Statistical, Prognosis, Remission Induction, Risk Factors, Treatment Outcome, Epilepsy diagnosis
- Abstract
Knowing the prognosis of epilepsy will undoubtedly influence the treatment strategy. This study aimed to define the prospects of newly diagnosed childhood epilepsy, assess the dynamics of its course, identify relevant variables and develop models to assess the individual prognosis. Four hundred and fifty-three children with newly diagnosed epilepsy were followed for 5 years. Terminal remission at 5 years (TR5) was compared with terminal remission at 2 years (TR2) and with the longest remission during follow-up. Variables defined at intake and at 6 months of follow-up were analysed for their prognostic relevance. In multivariate analyses, combinations of variables were tested to develop reliable models for the calculation of the individual prognosis. Data on treatment, course during follow-up and epilepsy syndromes were also studied. Three hundred and forty-five children (76%) had a TR5 >1 year, 290 (64%) >2 years and 65 (14%) had not had any seizure during the entire follow-up. Out of 108 children (24%) with TR5 <1 year, 27 were actually intractable at 5 years. Medication was started in 388 children (86%). In 227 of these (59%), anti-epileptic drugs (AEDs) could be withdrawn. A TR5 >1 year was attained by 46% on one AED, on the second AED by 19%, and by 9% on all additional AED regimes. Almost 60% of the children treated with a second or additional AED regime had a TR5 >1 year. Variables predicting the outcome at intake were aetiology, history of febrile seizures and age. For intake and 6-month variables combined, sex, aetiology, postictal signs, history of febrile seizures and TR at 6 months were significant. The model derived from intake variables only predicted TR5 <1 year correctly in 36% and TR5 >1 year in 85% (sensitivity 0.65, specificity 0.64). The corresponding values for the model derived from intake and 6-month variables were 43 and 88% (sensitivity 0.69, specificity 0.71). The course of the epilepsy was constantly favourable in 51%, steadily poor in 17%, improving in 25% and deteriorating in 6%. Intractability was in part only a temporary phenomenon. The outcome at 5 years in this cohort of children with newly diagnosed epilepsy was favourable in 76%; 64% were off medication at that time. Almost a third of the children had a fluctuating course; improvement was clearly more common than deterioration. After failure of the first AED, treatment can still be successful. Models predicting the outcome have fewer misclassifications when predicting a long terminal remission than when predicting continuing seizures.
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- 2004
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43. Interrater agreement of the diagnosis and classification of a first seizure in childhood. The Dutch Study of Epilepsy in Childhood.
- Author
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Stroink H, van Donselaar CA, Geerts AT, Peters AC, Brouwer OF, van Nieuwenhuizen O, de Coo RF, Geesink H, and Arts WF
- Subjects
- Child, Child, Preschool, Female, Humans, Male, Observer Variation, Severity of Illness Index, Epilepsy classification, Epilepsy diagnosis, Epilepsy epidemiology
- Abstract
Objective: To assess the interrater agreement of the diagnosis and the classification of a first paroxysmal event in childhood., Methods: The descriptions of 100 first paroxysmal events were submitted to two panels each consisting of three experienced paediatric neurologists. Each observer independently made a diagnosis based on clinical judgment and thereafter a diagnosis based on predefined descriptive criteria. Then, the observers discussed all patients within their panel. The agreement between the six individual observers was assessed before discussion within each panel and after that, between the two panels., Results: Using their clinical judgement, the individual observers reached only fair to moderate agreement on the diagnosis of a first seizure (mean (SE) kappa 0.41 (0.03)). With use of defined descriptive criteria the mean (SE) kappa was 0.45 (0.03). The kappa for agreement between both panels after intra-panel discussion increased to 0.60 (0.06). The mean (SE) kappa for the seizure classification by individual observers was 0.46 (0.02) for clinical judgment and 0.57 (0.03) with use of criteria. After discussion within each panel the kappa between the panels was 0.69 (0.06). In 24 out of 51 children considered to have had a seizure, agreement was reached between the panels on a syndrome diagnosis. However, the epileptic syndromes were in most cases only broadly defined., Conclusions: The interrater agreement on the diagnosis of a first seizure in childhood is just moderate. This phenomenon hampers the interpretation of studies on first seizures in which the diagnosis is only made by one observer. The use of a panel increased the interrater agreement considerably. This approach is recommended at least for research purposes. Classification into clinically relevant syndromes is possible only in a very small minority of children with a single seizure.
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- 2004
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44. Not only a matter of epilepsy: early problems of cognition and behavior in children with "epilepsy only"--a prospective, longitudinal, controlled study starting at diagnosis.
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Oostrom KJ, Smeets-Schouten A, Kruitwagen CL, Peters AC, and Jennekens-Schinkel A
- Subjects
- Adolescent, Child, Child Behavior Disorders etiology, Cognition Disorders etiology, Educational Measurement, Educational Status, Female, Humans, Longitudinal Studies, Male, Risk Factors, Child Behavior Disorders epidemiology, Cognition Disorders epidemiology, Epilepsy complications
- Abstract
Objective: To understand early educational and behavioral predicament in childhood "epilepsy only.", Methods: A multicenter, prospective, longitudinal study was conducted of 51 outpatient schoolchildren with newly diagnosed idiopathic or cryptogenic epilepsy and 48 sex-matched classmate control subjects. All children underwent neuropsychological assessment 3 times within the first year after diagnosis; parents and teachers completed behavior questionnaires, and patients' parents were interviewed to inventory contextual adversity. Principal components analysis of cognition and behavior disclosed 6 major components that were related with the interview data (repeated measures analysis of variance)., Results: Despite similar intelligence and educational background, significantly more patients (51%) than control subjects (27%) required special educational assistance. Patients obtained worse scores across components of cognition and behavior. Parents and teachers perceived patients to have more behavioral problems. Differences between groups existed at pretreatment baseline. Over time, notwithstanding stable percentages of poor scores in both groups, nonpersistence of poor scores was impressive (each time other children scored poorly in other domains). Rather than epilepsy characteristics, contextual adversities were significant risk factors., Conclusion: Already in the earliest stage of the illness, children with epilepsy are liable to vicissitudes in cognitive and behavioral functioning. Contextual variables are all-important.
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- 2003
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45. DNA mismatch repair protein Msh6 is required for optimal levels of ultraviolet-B-induced apoptosis in primary mouse fibroblasts.
- Author
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Young LC, Peters AC, Maeda T, Edelmann W, Kucherlapati R, Andrew SE, and Tron VA
- Subjects
- Animals, Apoptosis radiation effects, Cell Survival physiology, Cell Survival radiation effects, Cells, Cultured, Fibroblasts cytology, Fibroblasts radiation effects, Mice, Mice, Knockout, Skin Neoplasms prevention & control, Tumor Suppressor Protein p53 genetics, Ultraviolet Rays adverse effects, Apoptosis physiology, DNA Repair physiology, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Fibroblasts physiology
- Abstract
Recent data support a role for DNA mismatch repair in the cellular response to some forms of exogenous DNA damage beyond that of DNA repair; cells with defective DNA mismatch repair have partial or complete failure to undergo apoptosis and/or G2M arrest following specific types of damage. We propose that the DNA mismatch repair Msh2/Msh6 heterodimer, responsible for the detection of DNA damage, promotes apoptosis in normal cells, thus protecting mammals from ultraviolet-induced malignant transformation. Using primary mouse embryonic fibroblasts derived from Msh6+/+ and Msh6-/- mice, we compare the response of DNA-mismatch repair-proficient and -deficient cells to ultraviolet B radiation. In the wild-type mouse embryonic fibroblasts, ultraviolet-B-induced increases in Msh6 protein levels were not dependent on p53. Msh6-/- mouse embryonic fibroblasts were significantly less sensitive to the cytotoxic effects of ultraviolet B radiation. Further comparison of the Msh6+/+ and Msh6-/- mouse embryonic fibroblasts revealed that Msh6-/- mouse embryonic fibroblasts undergo significantly less apoptosis following ultraviolet B irradiation, thus indicating that ultraviolet-B-induced apoptosis is partially Msh6 dependent. These data support a role for Msh6 in protective cellular responses of primary cells to ultraviolet-B-induced mutagenesis and, hence, the prevention of skin cancer.
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- 2003
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46. Case report: severe central nervous system involvement in juvenile dermatomyositis.
- Author
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Elst EF, Kamphuis SS, Prakken BJ, Wulffraat NM, van der Net J, Peters AC, and Kuis W
- Subjects
- Angiokeratoma complications, Central Nervous System Diseases complications, Central Nervous System Diseases therapy, Child, Child, Preschool, Dermatomyositis complications, Dermatomyositis therapy, Disease Progression, Fatal Outcome, Humans, Magnetic Resonance Angiography methods, Magnetic Resonance Imaging methods, Male, Risk Assessment, Seizures complications, Severity of Illness Index, Vasculitis complications, Angiokeratoma diagnosis, Central Nervous System Diseases diagnosis, Dermatomyositis diagnosis, Seizures diagnosis, Vasculitis diagnosis
- Abstract
We present 3 patients with juvenile dermatomyositis (JDM) and severe central nervous system (CNS) complications. All patients had at least 4 positive criteria of Bohan and Peter, which confirmed a definite diagnosis of JDM. They were all male, and had a relatively high creatinine kinase value at admission (1532-4260 U/l). Besides, progressive proximal muscle weakness and rash, one patient presented with rapid irreversible decline of vision. Ophthalmologic examination showed active vasculitis of the retina. After 2 weeks of treatment with immunosuppressive drugs and being in improved, relatively stable clinical condition, all 3 patients developed generalized tonic-clonic convulsions. Other causes of the neurological symptoms could be excluded. In all 3 patients, the course of JDM was fatal. The clinical symptoms and further investigations in our patients show CNS involvement in JDM. Although rarely reported, CNS vasculopathy can be a serious and life-threatening complication of JDM.
- Published
- 2003
47. [Developmental disorder in girls due to Rett syndrome].
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Pruissen DM, Sinke RJ, Terhal PA, Beemer FA, and Peters AC
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- Child, Developmental Disabilities genetics, Female, Genotype, Humans, Methyl-CpG-Binding Protein 2, Phenotype, Chromosomal Proteins, Non-Histone, DNA-Binding Proteins genetics, Mutation, Repressor Proteins, Rett Syndrome genetics
- Abstract
Three girls with Rett syndrome are presented. Patients A and B had initially exhibited normal development, patient C showed severe developmental delay from birth on. In all three stereotypical hand movements arose which led to Rett syndrome being suspected. For patients A and B the clinical diagnosis was further supported by the identification of mutations in the MECP2-gene. In patient C, the mutation found turned out to be a neutral variant. Rett syndrome is a X-linked developmental disorder, which is particularly prevalent in girls. In 70-90% of clinically diagnosed RS patients a mutation is detected. MECP2-mutations result in a far wider range of phenotypes than classic RS. Mutations of this gene also occur in boys, with or without Rett-syndrome type phenotypes.
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- 2003
48. Mammalian DNA mismatch repair protects cells from UVB-induced DNA damage by facilitating apoptosis and p53 activation.
- Author
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Peters AC, Young LC, Maeda T, Tron VA, and Andrew SE
- Subjects
- Animals, Mice, MutS Homolog 2 Protein, Phosphorylation, Proto-Oncogene Proteins genetics, Proto-Oncogene Proteins metabolism, Ultraviolet Rays adverse effects, Apoptosis physiology, DNA Damage radiation effects, DNA Repair, DNA-Binding Proteins, Tumor Suppressor Protein p53 physiology
- Abstract
DNA mismatch repair (MMR) is integral to the maintenance of genomic stability and more recently has been demonstrated to affect apoptosis and cell cycle arrest in response to a variety of adducts induced by exogenous agents. Comparing Msh2-null and wildtype mouse embryonic fibroblasts (MEFs), both primary and transformed, we show that Msh2 deficiency results in increased survival post-UVB, and that UVB-induced apoptosis is significantly reduced in Msh2-deficient cells. Furthermore, p53 phosphorylation at serine 15 is delayed or diminished in Msh2-deficient cells, suggesting that Msh2 may act upstream of p53 in a post-UVB apoptosis or growth arrest response pathway. Taken together, these data suggest that MMR heterodimers containing Msh2 may function as a sensor of UVB-induced DNA damage and influence the initiation of UVB-induced apoptosis, thus implicating MMR in protecting against UV-induced tumorigenesis.
- Published
- 2003
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49. Prognosis of haemorrhagic stroke in childhood: a long-term follow-up study.
- Author
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Blom I, De Schryver EL, Kappelle LJ, Rinkel GJ, Jennekens-Schinkel A, and Peters AC
- Subjects
- Adolescent, Adult, Brain diagnostic imaging, Brain pathology, Child, Child, Preschool, Female, Follow-Up Studies, Hematoma, Epidural, Cranial diagnosis, Humans, Infant, Magnetic Resonance Imaging, Male, Memory Disorders diagnosis, Memory Disorders etiology, Neuropsychological Tests, Prognosis, Quality of Life, Retrospective Studies, Subarachnoid Hemorrhage diagnosis, Time Factors, Tomography, X-Ray Computed, Cognition Disorders diagnosis, Cognition Disorders etiology, Hematoma, Epidural, Cranial complications, Subarachnoid Hemorrhage complications
- Abstract
Little is known about long-term physical sequelae, cognitive functioning, and quality of life of children who have had a haemorrhagic stroke. Fifty-six patients (29 females, 27 males) under 16 years of age at time of the bleeding were studied. Mean age at time of bleeding was 7.7 years (range 1 month to 15.9 years). The primary site and cause of the bleeding at baseline were determined. Occurrences of death, re-bleedings, and seizures during follow-up were recorded. Patients who survived were invited for a follow-up examination including physical check-up, general screening of cognition, and an inventory of subjective health perception. Thirteen children died directly as a result of the haemorrhage; nine experienced a recurrent bleeding, which was fatal in three; six children developed epileptic seizures. At follow-up 36 of 56 patients were still alive. Mean follow-up time was 10.3 years (range 1.3 to 19.9 years) and mean age was 18.6 years (range 1.8 to 34.1 years). There was no patient lost to follow-up. Five patients declined to visit the hospital. In 15 out of 31 patients who could be examined, no physical impairment was observed, 11 had a hemiparesis of varying severity, and three had symptoms of cerebellar ataxia. One child had persisting tetraparesis and one persisting paraparesis. Signs of cognitive deficits were found in 15 patients. Of the children who survive haemorrhagic stroke, the physical and functional prognosis is relatively good, as almost all children were independent at follow-up. However, only a quarter of the surviving children had no physical or cognitive deficit after a mean follow-up period of 10 years. The majority had low self-esteem as well as emotional, behavioural, and health problems.
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- 2003
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50. Immunoglobulins in children with epilepsy: the Dutch Study of Epilepsy in Childhood.
- Author
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Callenbach PM, Jol-Van Der Zijde CM, Geerts AT, Arts WF, Van Donselaar CA, Peters AC, Stroink H, Brouwer OF, and Van Tol MJ
- Subjects
- Adolescent, Anticonvulsants therapeutic use, Carbamazepine therapeutic use, Case-Control Studies, Chi-Square Distribution, Child, Child, Preschool, Epilepsy drug therapy, Female, Humans, Immunoglobulin A blood, Immunoglobulin G blood, Infant, Male, Netherlands, Statistics, Nonparametric, Valproic Acid therapeutic use, Epilepsy immunology, Immunoglobulins blood
- Abstract
In an unselected cohort of 282 children, serum immunoglobulin (Ig) concentrations were determined shortly after the first presentation with one or more unprovoked epileptic seizures and before the start of treatment with anti-epileptic drugs (AEDs), and after 9-18 months of AEDs use. At intake, IgA, IgG1, IgG2 and IgG4 concentrations were significantly higher than published reference values in healthy age-matched controls. In a subset of 127 children, Ig levels at intake were compared with those after AEDs use for 9-18 months. IgA and IgG4 levels had decreased significantly to normal concentrations, but IgG1 and IgG3 levels increased significantly. To determine the influence of AEDs, Ig levels in children who used carbamazepine or valproic acid monotherapy were analysed separately. The use of carbamazepine was associated with a significant decrease of IgA and IgG4 levels, and the use of valproic acid with a significant decrease of IgA and increase of IgG1 levels. In conclusion, humoral immunity is already altered in children shortly after the first presentation with epileptic seizures. Whether this is the consequence of an exogenous event, and to what extent this is related to an interaction of the central nervous system and the immune system, remains to be evaluated. Treatment with AEDs, such as carbamazepine and valproic acid, is associated with significant changes of Ig (sub)class concentrations.
- Published
- 2003
- Full Text
- View/download PDF
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