1
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Horton A, Loban K, Nugus P, Fortin MC, Gunaratnam L, Knoll G, Mucsi I, Chaudhury P, Landsberg D, Paquet M, Cantarovich M, Sandal S. Health System-Level Barriers to Living Donor Kidney Transplantation: Protocol for a Comparative Case Study Analysis. JMIR Res Protoc 2023; 12:e44172. [PMID: 36881454 PMCID: PMC10031444 DOI: 10.2196/44172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/24/2023] [Accepted: 01/25/2023] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Living donor kidney transplantation (LDKT) is the best treatment option for patients with kidney failure and offers significant medical and economic advantages for both patients and health systems. Despite this, rates of LDKT in Canada have stagnated and vary significantly across Canadian provinces, the reasons for which are not well understood. Our prior work has suggested that system-level factors may be contributing to these differences. Identifying these factors can help inform system-level interventions to increase LDKT. OBJECTIVE Our objective is to generate a systemic interpretation of LDKT delivery across provincial health systems with variable performance. We aim to identify the attributes and processes that facilitate the delivery of LDKT to patients, and those that create barriers and compare these across systems with variable performance. These objectives are contextualized within our broader goal of increasing rates of LDKT in Canada, particularly in lower-performing provinces. METHODS This research takes the form of a qualitative comparative case study analysis of 3 provincial health systems in Canada that have high, moderate, and low rates of LDKT performance (the percentage of LDKT to all kidney transplantations performed). Our approach is underpinned by an understanding of health systems as complex adaptive systems that are multilevel and interconnected, and involve nonlinear interactions between people and organizations, operating within a loosely bounded network. Data collection will comprise semistructured interviews, document reviews, and focus groups. Individual case studies will be conducted and analyzed using inductive thematic analysis. Following this, our comparative analysis will operationalize resource-based theory to compare case study data and generate explanations for our research question. RESULTS This project was funded from 2020 to 2023. Individual case studies were carried out between November 2020 and August 2022. The comparative case analysis will begin in December 2022 and is expected to conclude in April 2023. Submission of the publication is projected for June 2023. CONCLUSIONS By investigating health systems as complex adaptive systems and making comparisons across provinces, this study will identify how health systems can improve the delivery of LDKT to patients with kidney failure. Our resource-based theory framework will provide a granular analysis of the attributes and processes that facilitate or create barriers to LDKT delivery across multiple organizations and levels of practice. Our findings will have practice and policy implications and help inform transferrable competencies and system-level interventions conducive to increasing LDKT. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/44172.
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Affiliation(s)
- Anna Horton
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Katya Loban
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Peter Nugus
- Department of Family Medicine and the Institute of Health Sciences Education, McGill University, Montreal, QC, Canada
| | - Marie-Chantal Fortin
- Centre de recherche du Centre hospitalier de l'Université de Montréal, Montreal, QC, Canada
- Division of Nephrology, Department of Medicine, Centre hospitalier de l'Université de Montréal, Montreal, QC, Canada
| | - Lakshman Gunaratnam
- Matthew Mailing Centre for Translational Transplant Studies, Lawson Health Research Institute, London Health Sciences Centre, London, ON, Canada
- Division of Nephrology, Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Greg Knoll
- Division of Nephrology, Department of Medicine, University of Ottawa, Ottawa, ON, Canada
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Istvan Mucsi
- Ajmera Transplant Center and Division of Nephrology, University Health Network, Toronto, ON, Canada
- Division of Nephrology, University of Toronto, Toronto, ON, Canada
| | - Prosanto Chaudhury
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- Department of Surgery, McGill University Health Centre, Montreal, QC, Canada
| | - David Landsberg
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Michel Paquet
- Centre de recherche du Centre hospitalier de l'Université de Montréal, Montreal, QC, Canada
- Division of Nephrology, Department of Medicine, Centre hospitalier de l'Université de Montréal, Montreal, QC, Canada
| | - Marcelo Cantarovich
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Shaifali Sandal
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- Division of Experimental Medicine, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
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2
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Horton A, Loban K, Nugus P, Fortin M, Gunaratnam L, Knoll G, Mucsi I, Chaudhury P, Landsberg D, Paquet M, Cantarovich M, Sandal S. Health System–Level Barriers to Living Donor Kidney Transplantation: Protocol for a Comparative Case Study Analysis (Preprint).. [DOI: 10.2196/preprints.44172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
Abstract
BACKGROUND
Living donor kidney transplantation (LDKT) is the best treatment option for patients with kidney failure and offers significant medical and economic advantages for both patients and health systems. Despite this, rates of LDKT in Canada have stagnated and vary significantly across Canadian provinces, the reasons for which are not well understood. Our prior work has suggested that system-level factors may be contributing to these differences. Identifying these factors can help inform system-level interventions to increase LDKT.
OBJECTIVE
Our objective is to generate a systemic interpretation of LDKT delivery across provincial health systems with variable performance. We aim to identify the attributes and processes that facilitate the delivery of LDKT to patients, and those that create barriers and compare these across systems with variable performance. These objectives are contextualized within our broader goal of increasing rates of LDKT in Canada, particularly in lower-performing provinces.
METHODS
This research takes the form of a qualitative comparative case study analysis of 3 provincial health systems in Canada that have high, moderate, and low rates of LDKT performance (the percentage of LDKT to all kidney transplantations performed). Our approach is underpinned by an understanding of health systems as complex adaptive systems that are multilevel and interconnected, and involve nonlinear interactions between people and organizations, operating within a loosely bounded network. Data collection will comprise semistructured interviews, document reviews, and focus groups. Individual case studies will be conducted and analyzed using inductive thematic analysis. Following this, our comparative analysis will operationalize resource-based theory to compare case study data and generate explanations for our research question.
RESULTS
This project was funded from 2020 to 2023. Individual case studies were carried out between November 2020 and August 2022. The comparative case analysis will begin in December 2022 and is expected to conclude in April 2023. Submission of the publication is projected for June 2023.
CONCLUSIONS
By investigating health systems as complex adaptive systems and making comparisons across provinces, this study will identify how health systems can improve the delivery of LDKT to patients with kidney failure. Our resource-based theory framework will provide a granular analysis of the attributes and processes that facilitate or create barriers to LDKT delivery across multiple organizations and levels of practice. Our findings will have practice and policy implications and help inform transferrable competencies and system-level interventions conducive to increasing LDKT.
INTERNATIONAL REGISTERED REPORT
DERR1-10.2196/44172
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3
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Humbert O, Cadour N, Paquet M, Schiappa R, Poudenx M, Chardin D, Borchiellini D, Benisvy D, Ouvrier MJ, Zwarthoed C, Schiazza A, Ilie M, Ghalloussi H, Koulibaly PM, Darcourt J, Otto J. 18FDG PET/CT in the early assessment of non-small cell lung cancer response to immunotherapy: frequency and clinical significance of atypical evolutive patterns. Eur J Nucl Med Mol Imaging 2019; 47:1158-1167. [PMID: 31760467 DOI: 10.1007/s00259-019-04573-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 10/10/2019] [Indexed: 12/11/2022]
Abstract
PURPOSE This prospective study aimed (1) to assess the non-small cell lung cancer (NSCLC) evolutive patterns to immunotherapy using FDG-PET and (2) to describe their association with clinical outcome. DESIGN Fifty patients with metastatic NSCLC were included before pembrolizumab or nivolumab initiation. FDG-PET scan was performed at baseline and after 7 weeks of treatment (PETinterim1) and different criteria/parameters of tumor response were assessed, including PET response criteria in solid tumors (PERCIST). If a first PERCIST progressive disease (PD) without clinical worsening was observed, treatment was continued and a subsequent FDG-PET (PETinterim2) was performed at 3 months of treatment. Pseudo-progression (PsPD) was defined as a PERCIST response/stability on PETinterim2 after an initial PD. If a second PERCIST PD was assessed on PETinterim2, a homogeneous progression of lesions (termed immune homogeneous progressive-disease: iPDhomogeneous) was distinguished from a heterogeneous evolution (termed immune dissociated-response: iDR). A durable clinical benefit (DCB) of immunotherapy was defined as treatment continuation over a 6-month period. The association between PET evolutive profiles and DCB was assessed. RESULTS Using PERCIST on PETinterim1, 42% (21/50) of patients showed a response or stable disease, most of them (18/21) reached a DCB. In contrast, 58% (29/50) showed a PD, but more than one-third (11/29) were misclassified as they finally reached a DCB. No standard PETinterim1 criteria could accurately distinguished responding from non-responding patients. Treatment was continued in 19/29 of patients with a first PERCIST PD; the subsequent PETinterim2 demonstrated iPDhomogeneous, iDR and PsPD in 42% (8/19), 26% (5/19), and 32% (6/19), respectively. Whereas no patients with iPDhomogeneous experienced a DCB, all patients with iDR and PsPD reached a clinical benefit to immunotherapy. CONCLUSION In patients with a first PD on PERCIST and treatment continuation, a subsequent PET identifies more than half of them with iDR and PsPD, both patterns being strongly associated with a clinical benefit of immunotherapy.
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Affiliation(s)
- O Humbert
- Department of Nuclear Medicine, Centre Antoine-Lacassagne, Université Côte d'Azur (UCA), 33 Avenue de Valombrose, 06189, Nice, France. .,Laboratory Transporter in Imaging and Radiotherapy in Oncology (TIRO), UMR E 4320, CEA, UCA, Nice, France.
| | - N Cadour
- Department of Nuclear Medicine, Centre Antoine-Lacassagne, Université Côte d'Azur (UCA), 33 Avenue de Valombrose, 06189, Nice, France
| | - M Paquet
- Department of Nuclear Medicine, Centre Antoine-Lacassagne, Université Côte d'Azur (UCA), 33 Avenue de Valombrose, 06189, Nice, France
| | - R Schiappa
- Department of Biostatistics, Centre Antoine-Lacassagne, UCA, Nice, France
| | - M Poudenx
- Department of Medical Oncology, Centre Antoine-Lacassagne, UCA, Nice, France
| | - D Chardin
- Department of Nuclear Medicine, Centre Antoine-Lacassagne, Université Côte d'Azur (UCA), 33 Avenue de Valombrose, 06189, Nice, France.,Laboratory Transporter in Imaging and Radiotherapy in Oncology (TIRO), UMR E 4320, CEA, UCA, Nice, France
| | - D Borchiellini
- Department of Medical Oncology, Centre Antoine-Lacassagne, UCA, Nice, France.,Clinical Research and Innovation Office, Centre Antoine-Lacassagne, UCA, Nice, France
| | - D Benisvy
- Department of Nuclear Medicine, Centre Antoine-Lacassagne, Université Côte d'Azur (UCA), 33 Avenue de Valombrose, 06189, Nice, France
| | - M J Ouvrier
- Department of Nuclear Medicine, Centre Antoine-Lacassagne, Université Côte d'Azur (UCA), 33 Avenue de Valombrose, 06189, Nice, France
| | - C Zwarthoed
- Department of Nuclear Medicine, Centre Antoine-Lacassagne, Université Côte d'Azur (UCA), 33 Avenue de Valombrose, 06189, Nice, France
| | - A Schiazza
- Department of Nuclear Medicine, Centre Antoine-Lacassagne, Université Côte d'Azur (UCA), 33 Avenue de Valombrose, 06189, Nice, France
| | - M Ilie
- Laboratory of Clinical and Experimental Pathology, Hospital-Integrated Biobank (BB-0033-00025), Nice Hospital University, FHU OncoAge, UCA, Nice, France
| | - H Ghalloussi
- Department of Medical Oncology, Centre Antoine-Lacassagne, UCA, Nice, France
| | - P M Koulibaly
- Department of Nuclear Medicine, Centre Antoine-Lacassagne, Université Côte d'Azur (UCA), 33 Avenue de Valombrose, 06189, Nice, France
| | - J Darcourt
- Department of Nuclear Medicine, Centre Antoine-Lacassagne, Université Côte d'Azur (UCA), 33 Avenue de Valombrose, 06189, Nice, France.,Laboratory Transporter in Imaging and Radiotherapy in Oncology (TIRO), UMR E 4320, CEA, UCA, Nice, France
| | - J Otto
- Department of Medical Oncology, Centre Antoine-Lacassagne, UCA, Nice, France
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Petit M, Paquet M, Paulhac L, Kitchener P. Impact of serum on calcium transient assays performed on human-induced pluripotent stem cell-derived cardiomyocytes. Toxicol Lett 2018. [DOI: 10.1016/j.toxlet.2018.06.994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Paquet M, Shivappa N, Hebert J, Truong T, Guenel P. Dietary inflammatory potential and differentiated thyroid carcinoma: A population-based case-control study in New Caledonia. Rev Epidemiol Sante Publique 2018. [DOI: 10.1016/j.respe.2018.05.319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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6
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Levesque E, Paquet M, Ducharme A, Albert M, Denault A, Cartier R, Lamarche Y. CONTEMPORARY OUTCOMES OF EXTRACORPOREAL OXYGENATION USE IN CARDIAC SUPPORT. Can J Cardiol 2016. [DOI: 10.1016/j.cjca.2016.07.411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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7
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Knoll GA, Fergusson D, Chassé M, Hebert P, Wells G, Tibbles LA, Treleaven D, Holland D, White C, Muirhead N, Cantarovich M, Paquet M, Kiberd B, Gourishankar S, Shapiro J, Prasad R, Cole E, Pilmore H, Cronin V, Hogan D, Ramsay T, Gill J. Ramipril versus placebo in kidney transplant patients with proteinuria: a multicentre, double-blind, randomised controlled trial. Lancet Diabetes Endocrinol 2016; 4:318-26. [PMID: 26608067 DOI: 10.1016/s2213-8587(15)00368-x] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 09/14/2015] [Accepted: 09/15/2015] [Indexed: 01/13/2023]
Abstract
BACKGROUND Angiotensin-converting enzyme inhibitors have been shown to reduce the risk of end-stage renal disease and death in non-transplant patients with proteinuria. We examined whether ramipril would have a similar beneficial effect on important clinical outcomes in kidney transplant recipients with proteinuria. METHODS In this double-blind, placebo-controlled, randomised trial, conducted at 14 centres in Canada and New Zealand, we enrolled adult renal transplant recipients at least 3-months post-transplant with an estimated glomerular filtration rate (GFR) of 20 mL/min/1·73m(2) or greater and proteinuria 0·2 g per day or greater and randomly assigned them to receive either ramipril (5 mg orally twice daily) or placebo for up to 4 years. Patients completing the final 4-year study visit were invited to participate in a trial extension phase. Treatment was assigned by centrally generated randomisation with permuted variable blocks of 2 and 4, stratified by centre and estimated GFR (above or below 40 mL/min/1·73 m(2)). The primary outcome was a composite consisting of doubling of serum creatinine, end-stage renal disease, or death in the intention-to-treat population. The principal secondary outcome was the change in measured GFR. We ascertained whether any component of the primary outcome had occurred at each study visit (1 month and 6 months post-randomisation, then every 6 months thereafter). This trial is registered with ISRCTN, number 78129473. FINDINGS Between Aug 23, 2006, and March 28, 2012, 213 patients were randomised. 109 were allocated to placebo and 104 were allocated to ramipril, of whom 109 patients in the placebo group and 103 patients in the ramipril group were analysed and the trial is now complete. The intention to treat population (placebo n=109, ramipril n=103) was used for the primary analysis and the trial extension phase analysis. The primary outcome occurred in 19 (17%) of 109 patients in the placebo group and 14 (14%) of 103 patients in the ramipril group (hazard ratio [HR] 0·76 [95% CI 0·38-1·51]; absolute risk difference -3·8% [95% CI -13·6 to 6·1]). With extended follow-up (mean 48 months), the primary outcome occurred in 27 patients (25%) in the placebo group and 25 (24%) patients in the ramipril group (HR 0·96 [95% CI 0·55-1·65]); absolute risk difference: -0·5% (95% CI -12·0 to 11·1). There was no significant difference in the rate of measured GFR decline between the two groups (mean difference per 6-month interval: -0·16 mL/min/1·73m(2) (SE 0·24); p=0·49). 14 (14%) of patients died in the ramipril group and 11 (10%) in the placebo group, but the difference between groups was not statistically significant (HR 1·45 [95% CI 0·66 to 3·21]). Adverse events were more common in the ramipril group (39 [38%]) than in the placebo group (24 [22%]; p=0·02). INTERPRETATION Treatment with ramipril compared with placebo did not lead to a significant reduction in doubling of serum creatinine, end-stage renal disease, or death in kidney transplant recipients with proteinuria. These results do not support the use of angiotensin-converting enzyme inhibitors with the goal of improving clinical outcomes in this population. FUNDING Canadian Institutes of Health Research.
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Affiliation(s)
- Greg A Knoll
- Department of Medicine, University of Ottawa, Ottawa, ON, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute and Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, ON, Canada; Kidney Research Centre, Ottawa Hospital Research Institute and University of Ottawa, Ottawa, ON, Canada.
| | - Dean Fergusson
- Department of Medicine, University of Ottawa, Ottawa, ON, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute and Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Michaël Chassé
- Clinical Epidemiology Program, Ottawa Hospital Research Institute and Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Paul Hebert
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada
| | - George Wells
- Clinical Epidemiology Program, Ottawa Hospital Research Institute and Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Lee Anne Tibbles
- Division of Nephrology, Department of Medicine, University of Calgary, Calgary, AB, Canada
| | - Darin Treleaven
- Division of Nephrology, Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - David Holland
- Division of Nephrology, Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Christine White
- Division of Nephrology, Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Norman Muirhead
- Division of Nephrology, Department of Medicine, Western University, London, ON, Canada
| | - Marcelo Cantarovich
- Division of Nephrology, Department of Medicine, McGill University, Montreal, QC, Canada
| | - Michel Paquet
- Division of Nephrology, Department of Medicine, Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada
| | - Bryce Kiberd
- Division of Nephrology, Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Sita Gourishankar
- Division of Nephrology, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Jean Shapiro
- Division of Nephrology, Department of Medicine, Vancouver General Hospital, Vancouver, BC, Canada
| | - Ramesh Prasad
- Division of Nephrology, Department of Medicine, St Michael's Hospital, Toronto, ON, Canada
| | - Edward Cole
- Division of Nephrology, Department of Medicine, University Health Network, Toronto, ON, Canada
| | - Helen Pilmore
- Department of Renal Medicine, Auckland City Hospital and Department of Medicine, Auckland University, Auckland, New Zealand
| | - Valerie Cronin
- Kidney Research Centre, Ottawa Hospital Research Institute and University of Ottawa, Ottawa, ON, Canada
| | - Debora Hogan
- Clinical Epidemiology Program, Ottawa Hospital Research Institute and Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Tim Ramsay
- Clinical Epidemiology Program, Ottawa Hospital Research Institute and Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, ON, Canada
| | - John Gill
- Division of Nephrology, Department of Medicine, St Paul's Hospital, Vancouver, BC, Canada
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Falk A, Hébert C, Paquet M, Tran A, Peyrade F, Saada E, Reure J, Dassonville O, Poissonnet G, Bozec A, Thariat J, Leysalle A, Chand M, Benezery K. EP-1084: Elderly patients concomitant radiotherapy + cetuximab in locally advanced head and neck cancer. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32334-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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9
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Lee T, Paquet M, Larsson O, Pelletier J. Tumor cell survival dependence on the DHX9 DExH-box helicase. Oncogene 2016; 35:5093-105. [PMID: 26973242 PMCID: PMC5023453 DOI: 10.1038/onc.2016.52] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 01/13/2016] [Accepted: 02/01/2016] [Indexed: 12/23/2022]
Abstract
The ATP-dependent DExH/D-box helicase DHX9 is a key participant in a number of gene regulatory steps, including transcriptional, translational, microRNA-mediated control, DNA replication, and maintenance of genomic stability. DHX9 has also been implicated in tumor cell maintenance and drug response. Here, we report that inhibition of DHX9 expression is lethal to human cancer cell lines and murine Eµ−Myc lymphomas. Using a novel conditional shDHX9 mouse model, we demonstrate that sustained and prolonged (6 months) suppression of DHX9 does not result in any deleterious effects at the organismal level. Body weight, blood biochemistry, and histology of various tissues were comparable to control mice. Global gene expression profiling revealed that although reduction of DHX9 expression resulted in multiple transcriptome changes, these were relatively benign and did not lead to any discernible phenotype. Our results demonstrate a robust tolerance for systemic DHX9 suppression in vivo and support the targeting of DHX9 as an effective and specific chemotherapeutic approach.
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Affiliation(s)
- T Lee
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - M Paquet
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec
| | - O Larsson
- Department of Oncology-Pathology, Karolinska Institute, Stockholm, Sweden
| | - J Pelletier
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada.,Department of Oncology, McGill University, Montreal, Quebec, Canada.,Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Quebec, Canada
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10
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Acker P, Grégoire A, Rat M, Spottiswoode CN, van Dijk RE, Paquet M, Kaden JC, Pradel R, Hatchwell BJ, Covas R, Doutrelant C. Disruptive viability selection on a black plumage trait associated with dominance. J Evol Biol 2015; 28:2027-41. [PMID: 26249359 PMCID: PMC4949555 DOI: 10.1111/jeb.12717] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 07/26/2015] [Accepted: 08/01/2015] [Indexed: 11/30/2022]
Abstract
Traits used in communication, such as colour signals, are expected to have positive consequences for reproductive success, but their associations with survival are little understood. Previous studies have mainly investigated linear relationships between signals and survival, but both hump-shaped and U-shaped relationships can also be predicted, depending on the main costs involved in trait expression. Furthermore, few studies have taken the plasticity of signals into account in viability selection analyses. The relationship between signal expression and survival is of particular interest in melanin-based traits, because their main costs are still debated. Here, we first determined the main factors explaining variability in a melanin-based trait linked to dominance: the bib size of a colonial bird, the sociable weaver Philetairus socius. We then used these analyses to obtain a measure representative of the individual mean expression of bib size. Finally, we used capture-recapture models to study how survival varied in relation to bib size. Variation in bib size was strongly affected by year and moderately affected by age, body condition and colony size. In addition, individuals bearing small and large bibs had higher survival than those with intermediate bibs, and this U-shaped relationship between survival and bib size appeared to be more pronounced in some years than others. These results constitute a rare example of disruptive viability selection, and point towards the potential importance of social costs incurred by the dominance signalling function of badges of status.
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Affiliation(s)
- P Acker
- CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, Montpellier Cedex 05, France.,Laboratoire Évolution & Diversité Biologique (UMR 5174 EDB), Université Toulouse 3 Paul Sabatier - CNRS - ENFA, Toulouse, France
| | - A Grégoire
- CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, Montpellier Cedex 05, France
| | - M Rat
- Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
| | - C N Spottiswoode
- Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa.,Department of Zoology, University of Cambridge, Cambridge, UK
| | - R E van Dijk
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - M Paquet
- CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, Montpellier Cedex 05, France.,Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
| | - J C Kaden
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.,The Royal Zoological Society of Scotland, Edinburgh Zoo, Edinburgh, UK
| | - R Pradel
- CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, Montpellier Cedex 05, France
| | - B J Hatchwell
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - R Covas
- Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa.,CIBIO, University of Porto, Vairão, Portugal.,Biology Department, Science Faculty, University of Porto, Porto, Portugal
| | - C Doutrelant
- CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, Montpellier Cedex 05, France.,Percy FitzPatrick Institute, DST-NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa
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11
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Werner R, Stockfleth E, Connolly S, Correia O, Erdmann R, Foley P, Gupta A, Jacobs A, Kerl H, Lim H, Martin G, Paquet M, Pariser D, Rosumeck S, Röwert-Huber HJ, Sahota A, Sangueza O, Shumack S, Sporbeck B, Swanson N, Torezan L, Nast A. Evidence- and consensus-based (S3) Guidelines for the Treatment of Actinic Keratosis - International League of Dermatological Societies in cooperation with the European Dermatology Forum - Short version. J Eur Acad Dermatol Venereol 2015; 29:2069-79. [DOI: 10.1111/jdv.13180] [Citation(s) in RCA: 188] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 04/02/2015] [Indexed: 12/22/2022]
Affiliation(s)
- R.N. Werner
- Division of Evidence Based Medicine (dEBM), Department of Dematology, Venerology and Allergology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - E. Stockfleth
- Department of Dermatology, Venerology and Allergology; Skin Cancer Center (HTCC); Charité - Universitätsmedizin Berlin; Berlin Germany
| | - S.M. Connolly
- Department of Dermatology; Mayo Clinic; Scottsdale Arizona USA
| | - O. Correia
- Centro Dermatologia Epidermis; Instituto CUF and Faculty of Medicine of University of Porto; Porto Portugal
| | - R. Erdmann
- Division of Evidence Based Medicine (dEBM), Department of Dematology, Venerology and Allergology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - P. Foley
- Skin and Cancer Foundation Victoria; Carlton Victoria Australia
- St. Vincent's Hospital Melbourne; Fitzroy Victoria Australia
- The University of Melbourne; Melbourne Victoria Australia
| | - A.K. Gupta
- Division of Dermatology; Department of Medicine; University of Toronto; Toronto Ontario Canada
- Mediprobe Research Inc.; London Ontario Canada
| | - A. Jacobs
- Division of Evidence Based Medicine (dEBM), Department of Dematology, Venerology and Allergology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - H. Kerl
- Department of Dermatology; Medical University of Graz; Graz Austria
| | - H.W. Lim
- Department of Dermatology; Henry Ford Hospital; Detroit Michigan USA
| | - G. Martin
- Dermatology Laser Center of Maui; Kihei Hawaii USA
| | - M. Paquet
- Mediprobe Research Inc.; London Ontario Canada
| | - D.M. Pariser
- Division of Dermatology and Virginia Clinical Research Inc; Eastern Virginia Medical School; Norfolk Virginia USA
| | - S. Rosumeck
- Division of Evidence Based Medicine (dEBM), Department of Dematology, Venerology and Allergology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - H.-J. Röwert-Huber
- Division of Dermatopathology; Department of Dermatology, Venerology and Allergology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - A. Sahota
- Department of Dermatology; Whipps Cross University Hospital; London UK
| | - O.P. Sangueza
- Department of Pathology; Wake Forest Baptist Medical Center; Winston-Salem North Carolina USA
- Department of Dermatology; Wake Forest Baptist Medical Center; Winston-Salem North Carolina USA
| | - S. Shumack
- Department of Dermatology; Northern Medical School; University of Sydney; Sydney New South Wales Australia
| | - B. Sporbeck
- Division of Evidence Based Medicine (dEBM), Department of Dematology, Venerology and Allergology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - N.A. Swanson
- Dermatology, Surgery, and Otolaryngology; Oregon Health and Science University; Portland Oregon USA
- Surgical and Cosmetic Dermatology and Clinical Operations; Oregon Health and Science University Knight Cancer Institute; Portland Oregon USA
| | - L. Torezan
- Faculty of Medicine; Hospital das Clínicas; Universidade de São Paulo; São Paulo Brazil
| | - A. Nast
- Division of Evidence Based Medicine (dEBM), Department of Dematology, Venerology and Allergology; Charité - Universitätsmedizin Berlin; Berlin Germany
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12
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Le Galliard JF, Paquet M, Mugabo M. An experimental test of density-dependent selection on temperament traits of activity, boldness and sociability. J Evol Biol 2015; 28:1144-55. [PMID: 25865798 DOI: 10.1111/jeb.12641] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/10/2015] [Accepted: 04/07/2015] [Indexed: 11/30/2022]
Abstract
Temperament traits are seen in many animal species, and recent evolutionary models predict that they could be maintained by heterogeneous selection. We tested this prediction by examining density-dependent selection in juvenile common lizards Zootoca vivipara scored for activity, boldness and sociability at birth and at the age of 1 year. We measured three key life-history traits (juvenile survival, body growth rate and reproduction) and quantified selection in experimental populations at five density levels ranging from low to high values. We observed consistent individual differences for all behaviours on the short term, but only for activity and one boldness measure across the first year of life. At low density, growth selection favoured more sociable lizards, whereas viability selection favoured less active individuals. A significant negative correlational selection on activity and boldness existed for body growth rate irrespective of density. Thus, behavioural traits were characterized by limited ontogenic consistency, and natural selection was heterogeneous between density treatments and fitness traits. This confirms that density-dependent selection plays an important role in the maintenance of individual differences in exploration-activity and sociability.
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Affiliation(s)
- J-F Le Galliard
- CNRS, UMR 7618, iEES Paris, Université Pierre et Marie Curie, Paris, France.,CNRS/ENS UMS 3194, CEREEP - Ecotron IleDeFrance, École Normale Supérieure, St-Pierre-lès-Nemours, France
| | - M Paquet
- CNRS, UMR 7618, iEES Paris, Université Pierre et Marie Curie, Paris, France.,Percy Fitzpatrick Institute, DST/NRF Centre of Excellence, University of Cape Town, Cape Town, South Africa
| | - M Mugabo
- CNRS, UMR 7618, iEES Paris, Université Pierre et Marie Curie, Paris, France.,School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
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13
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Lambrot R, Xu C, Saint-Phar S, Chountalos G, Cohen T, Paquet M, Suderman M, Hallett M, Kimmins S. Low paternal dietary folate alters the mouse sperm epigenome and is associated with negative pregnancy outcomes. Nat Commun 2014; 4:2889. [PMID: 24326934 PMCID: PMC3863903 DOI: 10.1038/ncomms3889] [Citation(s) in RCA: 281] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 11/07/2013] [Indexed: 01/20/2023] Open
Abstract
Epidemiological studies suggest that a father's diet can influence offspring health. A proposed mechanism for paternal transmission of environmental information is via the sperm epigenome. The epigenome includes heritable information such as DNA methylation. We hypothesize that the dietary supply of methyl donors will alter epigenetic reprogramming in sperm. Here we feed male mice either a folate-deficient or folate-sufficient diet throughout life. Paternal folate deficiency is associated with increased birth defects in the offspring, which include craniofacial and musculoskeletal malformations. Genome-wide DNA methylation analysis and the subsequent functional analysis identify differential methylation in sperm of genes implicated in development, chronic diseases such as cancer, diabetes, autism and schizophrenia. While >300 genes are differentially expressed in offspring placenta, only two correspond to genes with differential methylation in sperm. This model suggests epigenetic transmission may involve sperm histone H3 methylation or DNA methylation and that adequate paternal dietary folate is essential for offspring health.
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Affiliation(s)
- R Lambrot
- 1] Department of Animal Science, McGill University, Ste Anne-de-Bellevue, Québec H9X3V9, Canada [2]
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14
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Abstract
In the developing nervous system, ordered neuronal activity patterns can occur even in the absence of sensory input and to investigate how these arise, we have used the model system of the embryonic chicken spinal motor circuit, focusing on motor neurons of the lateral motor column (LMC). At the earliest stages of their molecular differentiation, we can detect differences between medial and lateral LMC neurons in terms of expression of neurotransmitter receptor subunits, including CHRNA5, CHRNA7, GRIN2A, GRIK1, HTR1A and HTR1B, as well as the KCC2 transporter. Using patch-clamp recordings we also demonstrate that medial and lateral LMC motor neurons have subtly different activity patterns that reflect the differential expression of neurotransmitter receptor subunits. Using a combination of patch-clamp recordings in single neurons and calcium-imaging of motor neuron populations, we demonstrate that inhibition of nicotinic, muscarinic or GABA-ergic activity, has profound effects of motor circuit activity during the initial stages of neuromuscular junction formation. Finally, by analysing the activity of large populations of motor neurons at different developmental stages, we show that the asynchronous, disordered neuronal activity that occurs at early stages of circuit formation develops into organised, synchronous activity evident at the stage of LMC neuron muscle innervation. In light of the considerable diversity of neurotransmitter receptor expression, activity patterns in the LMC are surprisingly similar between neuronal types, however the emergence of patterned activity, in conjunction with the differential expression of transmitter systems likely leads to the development of near-mature patterns of locomotor activity by perinatal ages.
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Affiliation(s)
- Chris Law
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Canada
| | - Michel Paquet
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Canada
| | - Artur Kania
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Canada
- Departments of Anatomy and Cell Biology, and Biology, Division of Experimental Medicine, McGill University Montréal, Montréal, Canada, and Faculté de Médecine, Université de Montréal, Montréal, Canada
- * E-mail:
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15
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Gupta AK, Paquet M. Network meta-analysis of the outcome 'participant complete clearance' in nonimmunosuppressed participants of eight interventions for actinic keratosis: a follow-up on a Cochrane review. Br J Dermatol 2014; 169:250-9. [PMID: 23550994 DOI: 10.1111/bjd.12343] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2013] [Indexed: 12/20/2022]
Abstract
The conclusions of pairwise meta-analyses of interventions for actinic keratosis (AK) are limited due to the lack of direct comparison between some interventions. Consequently, we performed a network meta-analysis for eight treatments [5-aminolaevulinic acid (ALA)-photodynamic therapy (PDT), cryotherapy, diclofenac 3% in 2·5% hyaluronic acid (DCF/HA), 5-fluorouracil (5-FU) 0·5% or 5·0%, imiquimod (IMI) 5%, ingenol mebutate (IMB) 0·015-0·05%, methyl aminolaevulinate (MAL)-PDT and placebo/vehicle (including placebo-PDT)] to determine their relative efficacies. As part of a prior Cochrane systematic review, different databases and grey literature were searched for randomized controlled trials up to April 2012. The inclusion criteria were parallel-group studies with nonimmunosuppressed participants: (i) reporting 'participant complete clearance' and (ii) comparing at least two of the interventions. Thirty-two publications met the criteria and they included the following number of individual or pooled studies (n) and total number of participants (N) for the different interventions: 5-FU 0·5% (n = 4, N = 169), 5-FU 5·0% (n = 2, N = 44), ALA-PDT (n = 6, N = 739), cryotherapy (n = 2, N = 174), DCF/HA (n = 5, N = 299), IMI (n = 14, N = 1411), IMB (n = 3, N = 560), MAL-PDT (n = 7, N = 557) and placebo (n = 32, N = 2520). Network analyses using a random-effects Bayesian model were carried out with the software ADDIS v1.16.1. The interventions were ranked as follows based on calculated probabilities and odd ratios: 5-FU > ALA-PDT ≈ IMI ≈ IMB ≈ MAL-PDT > cryotherapy > DCF/HA > placebo. This efficacy ranking was obtained based on the current available data on 'participant complete clearance' from randomized controlled trials and the analysis model used. However, several other factors should also be considered when prescribing a treatment for AK.
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Affiliation(s)
- A K Gupta
- Department of Medicine, University of Toronto, Toronto, ON, Canada.
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16
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Gupta A, Richardson M, Paquet M. Systematic Review of Oral Treatments for Seborrheic Dermatitis. J Eur Acad Dermatol Venereol 2013; 28:16-26. [DOI: 10.1111/jdv.12197] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 05/15/2013] [Indexed: 11/26/2022]
Affiliation(s)
- A.K. Gupta
- Division of Dermatology; Department of Medicine; University of Toronto; Toronto ON Canada
- Mediprobe Laboratories; London ON Canada
| | | | - M. Paquet
- Mediprobe Laboratories; London ON Canada
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17
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Gupta AK, Paquet M. Network meta-analysis of the outcome 'participant complete clearance' in nonimmunosuppressed participants of eight interventions for actinic keratosis: a follow-up on a Cochrane review. Br J Dermatol 2013. [PMID: 23550994 DOI: 10.1111/bjd.12343.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The conclusions of pairwise meta-analyses of interventions for actinic keratosis (AK) are limited due to the lack of direct comparison between some interventions. Consequently, we performed a network meta-analysis for eight treatments [5-aminolaevulinic acid (ALA)-photodynamic therapy (PDT), cryotherapy, diclofenac 3% in 2·5% hyaluronic acid (DCF/HA), 5-fluorouracil (5-FU) 0·5% or 5·0%, imiquimod (IMI) 5%, ingenol mebutate (IMB) 0·015-0·05%, methyl aminolaevulinate (MAL)-PDT and placebo/vehicle (including placebo-PDT)] to determine their relative efficacies. As part of a prior Cochrane systematic review, different databases and grey literature were searched for randomized controlled trials up to April 2012. The inclusion criteria were parallel-group studies with nonimmunosuppressed participants: (i) reporting 'participant complete clearance' and (ii) comparing at least two of the interventions. Thirty-two publications met the criteria and they included the following number of individual or pooled studies (n) and total number of participants (N) for the different interventions: 5-FU 0·5% (n = 4, N = 169), 5-FU 5·0% (n = 2, N = 44), ALA-PDT (n = 6, N = 739), cryotherapy (n = 2, N = 174), DCF/HA (n = 5, N = 299), IMI (n = 14, N = 1411), IMB (n = 3, N = 560), MAL-PDT (n = 7, N = 557) and placebo (n = 32, N = 2520). Network analyses using a random-effects Bayesian model were carried out with the software ADDIS v1.16.1. The interventions were ranked as follows based on calculated probabilities and odd ratios: 5-FU > ALA-PDT ≈ IMI ≈ IMB ≈ MAL-PDT > cryotherapy > DCF/HA > placebo. This efficacy ranking was obtained based on the current available data on 'participant complete clearance' from randomized controlled trials and the analysis model used. However, several other factors should also be considered when prescribing a treatment for AK.
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Affiliation(s)
- A K Gupta
- Department of Medicine, University of Toronto, Toronto, ON, Canada.
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18
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Yuki K, Eva M, Richer E, Chung D, Paquet M, Canonne-Hergaux F, Vaulont S, Vidal S, Malo D. Suppression of hepcidin expression and iron overload mediate Salmonella susceptibility in ankyrin 1 ENU-induced mutant. Int J Infect Dis 2012. [DOI: 10.1016/j.ijid.2012.05.386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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19
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Gupta A, Paquet M, Simpson F, Tavakkol A. Terbinafine in the treatment of dermatophyte toenail onychomycosis: a meta-analysis of efficacy for continuous and intermittent regimens. J Eur Acad Dermatol Venereol 2012; 27:267-72. [DOI: 10.1111/j.1468-3083.2012.04584.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Richer E, Yuki KE, Dauphinee SM, Larivière L, Paquet M, Malo D. Impact of Usp18 and IFN signaling in Salmonella-induced typhlitis. Genes Immun 2011; 12:531-43. [DOI: 10.1038/gene.2011.38] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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21
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Hudon V, Sabourin S, Dydensborg AB, Kottis V, Ghazi A, Paquet M, Crosby K, Pomerleau V, Uetani N, Pause A. Renal tumour suppressor function of the Birt-Hogg-Dubé syndrome gene product folliculin. J Med Genet 2009; 47:182-9. [PMID: 19843504 DOI: 10.1136/jmg.2009.072009] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Renal cell carcinoma (RCC) comprises five major molecular and histological subtypes. The Birt-Hogg-Dubé (BHD) syndrome is a hereditary human cancer syndrome that predisposes affected individuals to develop renal carcinoma of nearly all subtypes, in addition to benign fibrofolliculomas, and pulmonary and renal cysts. BHD is caused by loss-of-function mutations in the folliculin (FLCN) protein. The molecular function of FLCN is still largely unknown; opposite and conflicting evidence of the role of FLCN in mammalian target of rapamycin signalling/phosphorylated ribosomal protein S6 (p-S6) activation had recently been reported. RESULTS AND METHODS Here, the expression pattern of murine Flcn was described, and it was observed that homozygous disruption of Flcn results in embryonic lethality early during development. Importantly, heterozygous animals manifest early preneoplastic kidney lesions, devoid of Flcn expression, that progress towards malignancy, including cystopapillary adenomas. A bona fide tumour suppressor activity of FLCN was confirmed by nude mouse xenograft assays of two human RCC cell lines with either diminished or re-expressed FLCN. It was observed that loss of FLCN expression leads to context-dependent effects on S6 activation. Indeed, solid tumours and normal kidneys show decreased p-S6 upon diminished FLCN expression. Conversely, p-S6 is found to be elevated or absent in FLCN-negative renal cysts. CONCLUSION In accordance with clinical data showing distinct renal malignancies arising in BHD patients, in this study FLCN is shown as a general tumour suppressor in the kidney.
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Affiliation(s)
- V Hudon
- Goodman Cancer Centre, McGill University, Room 707A, McIntyre Building, 3655 Sir William Osler Promenade, Montréal, Québec, Canada H3G1Y6
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22
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Springer A, Shetty A, Elliott A, Paquet M, Wang J, Scwartz J, Hazle J, Stafford R. SU-GG-J-136: Nanoshell-Mediated Laser Induced Thermal Therapy in An In Vivo Model. Med Phys 2008. [DOI: 10.1118/1.2961685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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23
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Jasaitis Y, Sergent F, Bridoux V, Paquet M, Marpeau L, Ténière P. Prise en charge des grossesses après anneau gastrique ajustable. ACTA ACUST UNITED AC 2007; 36:764-9. [PMID: 17512137 DOI: 10.1016/j.jgyn.2007.03.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Revised: 12/29/2006] [Accepted: 03/20/2007] [Indexed: 10/28/2022]
Abstract
OBJECTIVES To report our experience of the association adjustable gastric banding and pregnancy. To define a management for a such association. MATERIALS AND METHODS Retrospective and descriptive study on two centers over a 3-year follow-up of pregnancies begun with a Lap-Band gastric banding placed by laparoscopic way. RESULTS Twenty-one pregnancies, 22 newborns resulting from 18 women were identified. Eleven patients were hospitalized. The motive of the hospitalization was severe epigastralgia for four patients requiring three deflations for mechanical complication. No case of preeclampsia was identified. Seven bands were deflated. In the group of the deflated bands, the mean maternal weight gain was 19 vs 10 kg (P=0.008), the mean birth weight was 3700 vs 3204 g (P=0.09) with a rate of fetal macrosomia increased, 50 vs 29% (P=0.038). The difference between the rates of cesarean delivery was not significant (NS) between the two groups. The childbirth term was appreciably the same, 39.4 vs 38.6 weeks of gestation (NS). The only case of gestational diabetes was found in the deflated band group. Three intrauterine growth restrictions whose one fetal death occurred in the not deflated band group. CONCLUSION Results obtained were comparable to those of the literature. This series confirms that adjustable gastric banding limits the usual complications of the morbid obesity during pregnancy. It is generally well tolerated and must not be thus deflated by principle, but only on symptoms. That will be a total dysphagia, severe epigastric pains, vomiting after the first trimester of pregnancy or an intrauterine growth restriction.
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Affiliation(s)
- Y Jasaitis
- Service de gynécologie obstétrique, CHU de Rouen, 76031 Rouen cedex, France
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24
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Sentilhes L, Sergent F, Popovic I, Fournet P, Paquet M, Marpeau L. Facteurs prédictifs de rupture utérine obstétricale après hystéroscopie opératoire. ACTA ACUST UNITED AC 2004; 33:51-5. [PMID: 14968056 DOI: 10.1016/s0368-2315(04)96313-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
OBJECTIVES To identify factors predictive of uterine rupture after operative hysteroscopy. When these factors are present, to search for means to prevent a later uterine rupture. Lastly to specify criteria allowing extraction of the fetus before rupture. PATIENTS AND METHODS Dramatic description of a case of uterine rupture, in a patient who presented a history of uterine perforation secondary to operative hysteroscopy and retrospective analysis of 12 similar observations reported in the literature. RESULTS Two types of situations must be differentiated: uncomplicated hysteroscopic resection of a polyp or sub-mucous fibroid does not seem to modify the obstetrical outcome; metroplasty for uterine malformation, complex synechia resections, and uterine perforations using monopolar current section are high-risk situations predictive of uterine rupture during pregnancy. CONCLUSION Uterine ruptures secondary to operative hysteroscopy are rare but serious. They can occur before onset of labor, and compromise vital maternofetal outcome. Risk factors can be identified, but nothing can prevent natural history towards uterine rupture during pregnancy. The obstetrician's vigilance in this context must be extreme searching for the least clinical sign in favor of a pre-rupture of the uterus. Furthermore, systematic caesarean is not justified.
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Affiliation(s)
- L Sentilhes
- Clinique Gynécologique et Obstétricale, Hôpital Charles Nicolle, 1, rue de Germont, 76031 Rouen Cedex.
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25
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Boyer A, Paquet M, Raiwet D, Daneau I, Harrison W, Silversides DW. Rapid genomic identification of transgenic integration sites for mouse insertional mutants. Biotechniques 2003; 34:32-4, 36. [PMID: 12545534 DOI: 10.2144/03341bm03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- A Boyer
- University of Montreal, St-Hyacinthe, Québec, Canada
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26
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Xu J, Paquet M, Lau AG, Wood JD, Ross CA, Hall RA. beta 1-adrenergic receptor association with the synaptic scaffolding protein membrane-associated guanylate kinase inverted-2 (MAGI-2). Differential regulation of receptor internalization by MAGI-2 and PSD-95. J Biol Chem 2001; 276:41310-7. [PMID: 11526121 DOI: 10.1074/jbc.m107480200] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The beta1-adrenergic receptor (beta1AR) is known to be localized to synapses and to modulate synaptic plasticity in many brain regions, but the molecular mechanisms determining beta1AR subcellular localization are not fully understood. Using overlay and pull-down techniques, we found that the beta1AR carboxyl terminus associates with MAGI-2 (membrane-associated guanylate kinase inverted-2), a protein also known as S-SCAM (synaptic scaffolding molecule). MAGI-2 is a multidomain scaffolding protein that contains nine potential protein-protein interaction modules, including 6 PDZ domains, 2 WW domains, and a guanylate kinase-like domain. The beta1AR carboxyl terminus binds with high affinity to the first PDZ domain of MAGI-2, with the last few amino acids of the beta1AR carboxyl terminus being the key determinants of the interaction. In cells, the association of full-length beta1AR with MAGI-2 occurs constitutively and is enhanced by agonist stimulation of the receptor, as assessed by both co-immunoprecipitation experiments and immunofluorescence co-localization studies. Agonist-induced internalization of the beta1AR is markedly increased by co-expression with MAGI-2. Strikingly, this result is the opposite of the effect of co-expression with PSD-95, a previously reported binding partner of the beta1AR. Further cellular experiments revealed that MAGI-2 has no effect on beta1AR oligomerization but does promote association of beta1AR with the cytoplasmic signaling protein beta-catenin, a known MAGI-2 binding partner. These data reveal that MAGI-2 is a specific beta1AR binding partner that modulates beta1AR function and facilitates the physical association of the beta1AR with intracellular proteins involved in signal transduction and synaptic regulation.
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Affiliation(s)
- J Xu
- Department of Pharmacology, Rollins Research Center, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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27
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Smith Y, Charara A, Paquet M, Kieval JZ, Paré JF, Hanson JE, Hubert GW, Kuwajima M, Levey AI. Ionotropic and metabotropic GABA and glutamate receptors in primate basal ganglia. J Chem Neuroanat 2001; 22:13-42. [PMID: 11470552 DOI: 10.1016/s0891-0618(01)00098-9] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The functions of glutamate and GABA in the CNS are mediated by ionotropic and metabotropic, G protein-coupled, receptors. Both receptor families are widely expressed in basal ganglia structures in primates and nonprimates. The recent development of highly specific antibodies and/or cDNA probes allowed the better characterization of the cellular localization of various GABA and glutamate receptor subtypes in the primate basal ganglia. Furthermore, the use of high resolution immunogold techniques at the electron microscopic level led to major breakthroughs in our understanding of the subsynaptic and subcellular localization of these receptors in primates. In this review, we will provide a detailed account of the current knowledge of the localization of these receptors in the basal ganglia of humans and monkeys.
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Affiliation(s)
- Y Smith
- Division of Neuroscience, Yerkes Regional Primate Research Center, Emory University, 954, Gatewood Rd NE, Atlanta, GA 30322, USA.
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Hubert GW, Paquet M, Smith Y. Differential subcellular localization of mGluR1a and mGluR5 in the rat and monkey Substantia nigra. J Neurosci 2001; 21:1838-47. [PMID: 11245668 PMCID: PMC6762609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2000] [Revised: 12/08/2000] [Accepted: 12/22/2000] [Indexed: 02/19/2023] Open
Abstract
Neurons in the rat substantia nigra (SN) are enriched in group I metabotropic glutamate receptor (mGluR) subtypes and respond to group I mGluR activation. To better understand the mechanisms by which mGluR1 and mGluR5 mediate these effects, the goal of this study was to elucidate the subsynaptic localization of these two receptor subtypes in the rat and monkey substantia nigra. At the light microscope level, neurons of the SN pars reticulata (SNr) displayed moderate to strong immunoreactivity for both mGluR1a and mGluR5 in rats and monkeys. However, mGluR1a labeling was much stronger in monkey than in rat SN pars compacta (SNc) neurons, whereas a moderate level of mGluR5 immunoreactivity was found in both species. At the electron microscope level, the immunoreactivity for both group I mGluR subtypes was primarily expressed postsynaptically, although light mGluR1a labeling was occasionally seen in axon terminals in the rat SNr. Immunogold studies revealed a striking difference in the subcellular distribution of mGluR1a and mGluR5 immunoreactivity in SNr and SNc neurons. Although the bulk of mGluR1a was attached to the plasma membrane, >80% of mGluR5 immunoreactivity was intracellular. Plasma membrane-bound immunoreactivity for group I mGluRs in both SNc and SNr neurons was mostly extrasynaptic or in the main body of symmetric, putative GABAergic synapses. On the other hand, asymmetric synapses either were nonimmunoreactive or displayed perisynaptic labeling. These data raise important questions about the trafficking, internalization, and potential functions of group I mGluRs at extrasynaptic sites or symmetric synapses in the substantia nigra.
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Affiliation(s)
- G W Hubert
- Yerkes Regional Primate Research Center, Division of Neuroscience and Department of Neurology, Emory University, Atlanta, Georgia 30322, USA
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Abstract
N-methyl-D-aspartate (NMDA) receptors are commonly found post-synaptically; they mediate fast excitatory neurotransmission in the central nervous system. In this study, we provide immunocytochemical data supporting the existence of presynaptic NMDA receptors in GABAergic terminals using polyclonal antisera raised against the C-terminus of the NMDAR1 subunit. At the light microscope level, rich plexuses of NMDAR1-positive varicose fibers were found in various nuclei in the basal forebrain (bed nucleus of stria terminalis, septum, parastrial nucleus, vascular organ of the lamina terminalis), thalamus (paraventricular nucleus, midline nuclei), and hypothalamus (parvocellular paraventricular nucleus, arcuate nucleus, preoptic nucleus, suprachiasmatic nucleus). In the brainstem, labeled fibers were much less abundant and were confined to the ventral tegmental area, periaqueductal gray, parabrachial nucleus, and locus coeruleus. At the electron microscope level, NMDAR1-immunoreactive terminals examined in the bed nucleus of stria terminalis, parvocellular paraventricular hypothalamic nucleus, and arcuate nucleus formed symmetric synapses, contained darkly stained large dense-core vesicles, and displayed gamma-aminobutyric acid (GABA) immunoreactivity. Terminals with similar ultrastructural features were found in the paraventricular thalamic nucleus. These findings demonstrate the existence of NMDAR1 subunit immunoreactivity in subsets of GABAergic terminals, which raises questions about the potential roles and mechanisms of activation of presynaptic NMDA heteroreceptors in the rat central nervous system. The pattern of distribution and ultrastructural features of these boutons suggest that they may arise from local GABAergic projections interconnecting a group of brain structures mediating stress responses and/or other endocrine, autonomic, and limbic functions.
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Affiliation(s)
- M Paquet
- Yerkes Regional Primate Research Center, Division of Neuroscience and Department of Neurology, Emory University, Atlanta, Georgia 30329, USA
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Abstract
Glutamate and GABA neurotransmission is mediated through various types of ionotropic and metabotropic receptors. In this review, we summarise some of our recent findings on the subcellular and subsynaptic localisation of GABA(B) and group I metabotropic glutamate receptors in the striatopallidal complex of monkeys. Polyclonal antibodies that specifically recognise GABA(B)R1, mGluR1a and mGluR5 receptor subtypes were used for immunoperoxidase and pre-embedding immunogold techniques at the light and electron microscope levels. Both subtypes of group I mGluRs were expressed postsynaptically in striatal projection neurons and interneurons where they aggregate perisynaptically at asymmetric glutamatergic synapses and symmetric dopaminergic synaptic junctions. Moreover, they are also strongly expressed in the main body of symmetric synapses established by putative intrastriatal GABAergic terminals. In the globus pallidus, both receptor subtypes are found postsynaptically in the core of striatopallidal GABAergic synapses and perisynaptically at subthalamopallidal glutamatergic synapses. Finally, extrasynaptic labelling was commonly seen in the globus pallidus and the striatum. Moderate to intense GABA(B)R1 immunoreactivity was observed in the striatopallidal complex. At the electron microscope level, GABA(B)R1 immunostaining was commonly found in neuronal cell bodies and dendrites. Many striatal dendritic spines also displayed GABA(B)R1 immunoreactivity. Moreover, GABA(B)R1-immunoreactive axons and axon terminals were frequently encountered. In the striatum, GABA(B)R1-immunoreactive boutons resembled terminals of cortical origin, while in the globus pallidus, subthalamic-like terminals were labelled. Pre-embedding immunogold data showed that postsynaptic GABA(B)R1 receptors are concentrated at extrasynaptic sites on dendrites, spines and somata in the striatopallidal complex, perisynaptically at asymmetric synapses and in the main body of symmetric striatopallidal synapses in the GPe and GPi. Consistent with the immunoperoxidase data, immunoparticles were found in the presynaptic grid of asymmetric synapses established by cortical- and subthalamic-like glutamatergic terminals. These findings indicate that both GABA and glutamate metabotropic receptors are located to subserve various modulatory functions of the synaptic transmission in the primate striatopallidal complex. Furthermore, their pattern of localisation raises issues about their roles and mechanisms of activation in normal and pathological conditions. Because of their 'modulatory' functions, these receptors are ideal targets for chronic drug therapies in neurodegenerative diseases such as Parkinson's disease.
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Affiliation(s)
- Y Smith
- Division of Neuroscience, Yerkes Regional Primate Research Center, Emory University, Atlanta, Georgia 30329, USA.
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Paquet M. [Sciences of power, power of sciences, several trends in the Canadian historiography of sciences]. Acadiensis 2000; 30:92-103. [PMID: 17111550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
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Dewar KM, Paquet M, Sequeira A. Apparent dopamine D1 and D2 receptors in the weaver mutant mouse: receptor binding and coupling to adenylyl cyclase. J Neural Transm (Vienna) 1999; 106:487-97. [PMID: 10443552 DOI: 10.1007/s007020050173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Weaver mutant mice have a selective degeneration of the nigrostriatal dopamine pathway arising between 7-21 days after birth. The goal of this study was to investigate the effects of this mutation on different parameters of the nigrostriatal and mesolimbic dopamine system: apparent D1 and D2 receptor binding sites as well as their signal transduction pathway. Using quantitative autoradiography of ligands for dopamine D1, D2 receptors and the dopamine uptake site, we found a significant loss in apparent D1 receptor binding sites throughout the neostriatum, significant increase of apparent D2 receptor binding in the dorsal aspect of the neostriatum, and almost complete loss of DA uptake sites in these regions of the weaver mouse. In contrast to the neostriatum, the density of dopamine receptors and uptake sites in the nucleus accumbens of the weaver mouse did not differ from controls. Despite alterations in the binding of apparent D1 and D2 receptors, there was no significant difference in either basal, DA stimulated or GTPgammaS stimulated cAMP production. These findings suggest the down-regulation of apparent D1 receptor binding sites reported in this model, probably does not reflect an important physiological mechanism through which these animals compensate for loss of dopamine innervation.
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Affiliation(s)
- K M Dewar
- Hôpital Louis-H. Lafontaine, Département de Psychiatrie, Université de Montréal, Québec, Canada
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Couceyro P, Paquet M, Koylu E, Kuhar MJ, Smith Y. Cocaine- and amphetamine-regulated transcript (CART) peptide immunoreactivity in myenteric plexus neurons of the rat ileum and co-localization with choline acetyltransferase. Synapse 1998; 30:1-8. [PMID: 9704875 DOI: 10.1002/(sici)1098-2396(199809)30:1<1::aid-syn1>3.0.co;2-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cocaine and amphetamine regulated transcript (CART) encodes a novel brain-enriched protein whose features are reminiscent of a neurotransmitter propeptide. We have now localized CART peptide(s) in the gastrointestinal tract by immunohistochemical methods. Polyclonal antisera raised to CART peptide 106-129 stained neuronal cell bodies and fibers in rat ileum myenteric plexus-longitudinal muscle tissue preparations. Electron microscopic analysis of thin sections showed immunopositive axon terminals in close apposition to CART-labelled and unlabelled neuronal cell bodies as well as to the longitudinal muscle. CART peptide-immunoreactive terminals contained numerous ovoid electron-lucent vesicles and a few dark-stained dense-core vesicles. Light microscopic double labelling studies revealed CART peptide immunoreactivity in a subpopulation of choline acetyltransferase (ChAT)-immunoreactive neurons. This combined light microscopic and ultrastructural examination of CART peptides in the gastrointestinal tract suggests a role of CART peptides as transmitters or neuromodulators in the peripheral nervous system.
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Affiliation(s)
- P Couceyro
- Division of Neuroscience, Yerkes Regional Primate Research Center and Emory University, Atlanta, Georgia 30329, USA.
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Paquet M, Benson L, Coe Y, Houde C, Human D. [Standards of heart catheterization and interventional cardiology in pediatrics]. Can J Cardiol 1998; 14:1013-6. [PMID: 9738160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Affiliation(s)
- M Paquet
- Département de pédiatrie, Faculté de médecine, Université de Sherbrooke, (Québec).
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Germain JM, Czernichow P, Josset V, Torre JP, Marpeau L, Le Meur H, Paquet M, Pellerin MA, Hebert A. [Quality of data acceptable for perinatal epidemiology surveillance: assessment of the health certificate at birth and the national obstetrics medical file. Study in three Seine-Maritime maternal wards]. J Gynecol Obstet Biol Reprod (Paris) 1998; 27:384-8. [PMID: 9690156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Data from several sources could be used for perinatal epidemiology surveillance aimed at an assessment of regional programs such as those proposed by the Superior Committee for Public Health. A retrospective study of 561 births was conducted in three maternity wards in the French Seine Maritime department in order to evaluate the reliability of two data sources: the national obstetrics medical file and the health certificate at birth. The delivery room records were used as the gold standard. The sensitivity of the obstetrics file was better than that of the health certificate. With the obstetrics file, it was possible to identify almost all the vaginal route interventions, almost all the premature births and all the cesareans. With the health certificate, 39-58% of the vaginal route interventions, 61% of the premature births and 61-72% of the cesareans performed in the three wards studied were identified. The quality of data in the obstetrics file appears to be better than that in the health certificate but only concerns 40% of births in the geographical area studied. Inversely, the health certificate is theoretically delivered for all births (actually delivered for 93%). Integrating these two information systems could be an optimum solution.
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Affiliation(s)
- J M Germain
- Département d'Epidémiologie et de Santé Publique, CHU, Rouen
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Lê KT, Paquet M, Nouel D, Babinski K, Séguéla P. Primary structure and expression of a naturally truncated human P2X ATP receptor subunit from brain and immune system. FEBS Lett 1997; 418:195-9. [PMID: 9414125 DOI: 10.1016/s0014-5793(97)01380-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A novel member of the ionotropic ATP receptor gene family has been identified in human brain. This 422 amino acid long P2X receptor subunit has 62% sequence identity with rat P2X5. Several characteristic motifs of ATP-gated channels are present in its primary structure, but this P2X5-related subunit displays a single transmembrane domain. Heterologous expression of chimeric subunits containing the C-terminal domain of rat P2X5 leads to the formation of desensitizing functional ATP-gated channels in Xenopus oocytes. The developmentally regulated mRNA, found in two splicing variant forms, is expressed at high levels in brain and immune system.
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Affiliation(s)
- K T Lê
- Cell Biology of Excitable Tissue Group, Montreal Neurological Institute, McGill University, Que., Canada
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Tchervenkov CI, Salasidis G, Cecere R, Béland MJ, Jutras L, Paquet M, Dobell AR. One-stage midline unifocalization and complete repair in infancy versus multiple-stage unifocalization followed by repair for complex heart disease with major aortopulmonary collaterals. J Thorac Cardiovasc Surg 1997; 114:727-35; discussion 735-7. [PMID: 9375602 DOI: 10.1016/s0022-5223(97)70076-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries have traditionally required multiple unifocalization staging operations before undergoing complete repair. Recently, the feasibility of a single-stage unifocalization and repair was demonstrated by Hanley. In this report, we describe our experience with each approach. METHODS AND RESULTS Since 1989, 11 of 12 patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries have undergone complete surgical correction. The first seven patients were subjected to staged bilateral unifocalizations, with repair being achieved in six (group I). The last five patients have undergone a single-stage midline unifocalization and repair via a sternotomy (group II). Four of these were infants (2 weeks to 9 months) and one was 13 years old. All patients in group I had tetralogy of Fallot, whereas in group II three patients had tetralogy of Fallot, one patient had double-outlet right ventricle, and one patient had complete atrioventricular canal and transposition. In group I, the median age at the first operation was 43 weeks. Complete repair was performed at a median age of 3.5 years, with a mean number of 3.3 operations required. In group II, only one operation was required to achieve complete repair at a median age of 28 weeks. The postoperative right ventricular/left ventricular pressure ratio was 0.49 in group I and 0.45 in group II. One intraoperative death and one late death occurred in group I and no early or late deaths in group II. Currently, four patients in group I and all five patients in group II are alive and well. CONCLUSIONS Early intervention with both surgical approaches can lead to complete biventricular repair in most patients. Because the single-stage midline unifocalization and repair can achieve a completely repaired heart in infancy with one operation, it is currently our approach of choice.
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Affiliation(s)
- C I Tchervenkov
- Division of Cardiovascular Surgery, Montreal Children's Hospital, McGill University, Quebec, Canada
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Botto JM, Chabry J, Nouel D, Paquet M, Séguéla P, Vincent JP, Beaudet A, Mazella J. Identification in the rat neurotensin receptor of amino-acid residues critical for the binding of neurotensin. Brain Res Mol Brain Res 1997; 46:311-7. [PMID: 9191107 DOI: 10.1016/s0169-328x(97)00006-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In order to identify charged amino-acid residues of the cloned rat brain neurotensin (NT) receptor (NTR) that are critical for NT binding, we performed site-directed mutagenesis on the cDNA encoding this protein, followed by transient expression into mammalian COS-7 cells and in Xenopus laevis oocytes. Point substitutions of charged residues in the N-terminal part and in the 2nd and 3rd extracellular loop of the receptor either did not affect (125)I-Tyr3-NT binding or resulted in a decrease in binding affinity by a factor of 2-3. Mutations of amino acids Asp113 in the second transmembrane domain (TM) and of Arg149 or Asp150 in TM III yielded receptors that bound NT as efficiently as the native receptor. By contrast, replacement of the Asp139 residue in the 1st extracellular loop, or of Arg143 or Arg327-Arg328 residues at the top of TM III and in TM VI, respectively, completely abolished ligand binding. Confocal and EM immunocytochemical studies of the expression of these affected receptors, tagged with the C-terminal sequence of the vesicular stomatitis virus glycoprotein (VSV-G), indicated that this loss of binding was not due to altered receptor expression or to their improper insertion into the plasma membrane. When these mutated forms of neurotensin receptor were expressed into Xenopus oocytes, Asp139-Gly- and Arg143-Gly-modified receptors remained functional in spite of a lowered response to NT whereas the Arg327-Arg328 mutant form was totally insensitive to NT at concentrations up to 10 microM. In the case of the Arg327-Arg328 mutation, the observed insensibility to NT could be the result of a drastic conformational alteration of this mutant protein. By contrast, it would appear that Asp139 and Arg143 residues located in the first extracellular loop of the receptor may be directly involved in the interaction of the receptor with neurotensin.
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Affiliation(s)
- J M Botto
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS UPR 411, Valbonne, France
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Dewar KM, Paquet M, Reader TA. Alterations in the turnover rate of dopamine D1 but not D2 receptors in the adult rat neostriatum after a neonatal dopamine denervation. Neurochem Int 1997; 30:613-21. [PMID: 9153003 DOI: 10.1016/s0197-0186(96)00069-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Adult rats that were treated with intracerebral ventricular injection of 6-hydroxydopamine (6-OHDA) as neonates exhibit a profound loss of nigrostriatal dopamine innervation in addition to a variety of other neurochemical and anatomical changes, including alterations in the number of neostriatal D1 and D2 receptor binding sites. In the present study, the turnover of neostriatal dopamine D1 and D2 receptors was measured in rats previously treated with 6-OHDA or ascorbic acid vehicle as neonates at various time intervals after peripheral N-ethoxycarbonyl-2-ethoxy-1, 2-dihydroquinoline (EEDQ, 10 mg/kg) administration. Dopamine receptors were labelled with [3H]SCH23390 (D1) and [3H]raclopride (D2), while the degree of dopamine denervation was assessed by the measurement of neostriatal dopamine, homovanillic acid and dihydroxyphenylacetic acid content. Two days after acute EEDQ treatment, the maximal binding capacity (Bmax) of [3H]SCH23390 and [3H]raclopride binding was significantly decreased to 58 and 32% of control values, respectively, without any significant alteration in their equilibrium dissociation constants (Kd). A time-dependent increase in the density of [3H]SCH23390 and [3H]raclopride binding was observed in both treatment groups following a single dose of EEDQ. The rate of recovery of D1 receptors was significantly slower in the 6-OHDA-lesioned animals as compared to controls with a half-life of 103 compared to 53 h, respectively. No differences were observed in the rate of recovery of D2 receptors in these two treatment groups. These data are consistent with the findings of decreased expression of D1 receptors in neonatal 6-OHDA-lesioned rats owing to decreased receptor synthesis, and further suggest that in this model the up-regulation of D2 receptors is a result of a post-transcriptional mechanism, such as an increased rate of post-synthetic maturation.
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Affiliation(s)
- K M Dewar
- Centre de recherche Fernand-Seguin, Départements de Physiologie et Psychiatrie, Faculté de Médecine, Université de Montréal, Québec, Canada
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Paquet M, Tremblay M, Soghomonian JJ, Smith Y. AMPA and NMDA glutamate receptor subunits in midbrain dopaminergic neurons in the squirrel monkey: an immunohistochemical and in situ hybridization study. J Neurosci 1997; 17:1377-96. [PMID: 9006980 PMCID: PMC6793718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/1996] [Revised: 10/04/1996] [Accepted: 12/03/1996] [Indexed: 02/03/2023] Open
Abstract
The objective of the present study was to analyze the cellular and subcellular localization of ionotropic glutamate receptor subunits in midbrain dopaminergic neurons in the squirrel monkey. This was achieved by means of immunohistochemistry at light and electron microscopic levels and in situ hybridization histochemistry. Colocalization studies show that nearly all dopaminergic neurons in both the ventral and dorsal tiers of the substantia nigra compacta (SNc-v, SNc-d) and the ventral tegmental area (VTA) are immunoreactive for AMPA (GluR1, GluR2/3, and GluR4) and NMDAR1 receptor subunits, but not for NMDAR2A/B subunits. The immunoreactivity of the receptor subunits is associated mainly with perikarya and dendritic shafts. Apart from the intensity of immunolabeling for the GluR4 subunit, which is quite similar for the different groups of midbrain dopaminergic neurons, the overall intensity of immunostaining for the other subunits is higher in the SNc-v and SNc-d than in the VTA. In line with these observations, in situ hybridization shows that the average level of labeling for the GluR2 and NMDAR1 subunit mRNAs is significantly higher in the SNc-v than in the VTA, and for the NMDAR1 subunit, higher in the SNc-v than in the SNc-d. In contrast, no significant difference was found for the level of GluR1 mRNA labeling among the three groups of midbrain dopaminergic neurons. At the subcellular level in the SNc-v, AMPA (GluR1 and GluR2/3) and NMDAR1 receptor subunit immunoreactivity is preferentially associated with the postsynaptic densities of asymmetric synapses, but occasionally some immunoreactivity is found along nonsynaptic portions of plasma membranes of dendrites. A small number of preterminal axons, axon terminals, and glial cell processes are also immunoreactive. Our observations indicate that the different groups of midbrain dopaminergic neurons in primates exhibit a certain degree of heterogeneity with regard to the level of expression of some ionotropic glutamate receptor subunits. The widespread neuronal and glial localization of glutamate receptor subunits suggests that excitatory amino acids may act at different levels to control the basal activity and, possibly, to participate in the degeneration of midbrain dopaminergic neurons in Parkinson's disease.
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Affiliation(s)
- M Paquet
- Centre de Recherche en Neurobiologie, Hôpital de l'Enfant-Jésus, Université Laval, Québec, Canada G1J 1Z4
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Paquet M, Smith Y. Differential localization of AMPA glutamate receptor subunits in the two segments of the globus pallidus and the substantia nigra pars reticulata in the squirrel monkey. Eur J Neurosci 1996; 8:229-33. [PMID: 8713467 DOI: 10.1111/j.1460-9568.1996.tb01184.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The subthalamic nucleus has long been known as the main source of glutamatergic afferents to the pallidum and the substantia nigra in primates. Recent findings showed that the excitatory effects induced by the subthalamic nucleus in pallidal cells are mediated through the activation of non-NMDA receptors in the rat. The objective of the present study was to analyse the distribution of alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) glutamate receptor subunits in the external pallidum (GPe), the internal pallidum (GPi) and the substantia nigra pars reticulata (SNr) in squirrel monkeys (Saimiri sciureus). This was achieved by means of immunohistochemistry using antibodies raised against the GluR1 and the GluR2/3 subunits of the AMPA receptor. Our results show that all neuronal perikarya in GPe and GPi display immunoreactivity for GluR2/3 subunits whereas GluR1 is confined exclusively to cells in the GPe. The proportion of GluR1-immunoreactive neurons is not uniform throughout the rostrocaudal extent of GPe; in the rostral third all GPe cells display GluR1 immunoreactivity, whereas in the caudal third the proportion of GluR1-positive cells decreases to 50%. The intensity of GluR1 immunostaining associated with GPe cells is lower than that associated with neighbouring large-sized neurons in the nucleus basalis of Meynert. In contrast to GPi cells, the neurons in the SNr display immunoreactivity for both GluR1 and GluR2/3 subunits. In conclusion, our results provide the first evidence for a different distribution of the GluR1 subunit of the AMPA receptors in the two segments of the globus pallidus in monkeys. These findings imply that the control of the basal activity of GPe and GPi cells by the subthalamic nucleus is exerted via the activation of AMPA receptors composed of different subunits. These data reinforce the view that the two segments of the globus pallidus are different entities that possess their own functional characteristics in primates.
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Affiliation(s)
- M Paquet
- Centre de Recherche en Neurobiologie, Hôpital de I'Enfant- Jésus and Université laval, Québec, Canada
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Tchervenkov CI, Marelli D, Béland MJ, Gibbons JE, Paquet M, Dobell AR. Institutional experience with a protocol of early primary repair of double-outlet right ventricle. Ann Thorac Surg 1995; 60:S610-3. [PMID: 8604947 DOI: 10.1016/0003-4975(95)00855-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Our institution has adopted a protocol of primary repair for all patients with double-outlet right ventricle. METHODS Since May 1989, 24 consecutive neonates and infants with double-outlet right ventricle and atrioventricular concordance (median age, 4 months) underwent anatomic biventricular repair. One patient (4%) received prior pulmonary artery banding but was still repaired as a neonate at 22 days of age. Twelve patients had a subaortic ventricular septal defect (VSD), 5 patients a subpulmonary VSD, 3 patients doubly committed VSD, and 4 patients a noncommitted VSD. Sixty-nine of 72 associated lesions were repaired simultaneously. Four types of repairs were used: intraventricular rerouting in 16 patients, arterial switch operation with VSD closure into the pulmonary artery in 4 patients, Rastelli-type repair with extracardiac conduit in 3 patients, and the Damus-Kaye-Stansel repair with concomitant repair of aortic arch obstruction in 1 patient. Ventricular septal defect enlargement was necessary in 15 patients. Repair of subpulmonary stenosis and of subaortic stenosis was carried out in 13 and 4 patients, respectively. Three patients underwent simultaneous repair of aortic arch obstruction with no mortality. Two of the patients with noncommitted VSD had simultaneous repair of complete atrioventricular canal and repair of severe pulmonary venous obstruction. RESULTS The perioperative mortality was 8% (2 patients, and there was one late death (4%). Two patients (9%) underwent early successful reoperations (5 and 8 weeks postoperatively). The two reoperations were for residual VSD (1 patient) and severe mitral regurgitation (1 patient). All 21 survivors are alive at a mean follow-up of 40 months (range, 7 months to 6 years). The estimated 5-year actuarial survival is 88%, with no deaths after 2 months postoperatively. Ninety-five percent of long-term survivors have no restriction of physical activities because of cardiac status and are receiving no cardiac medications. CONCLUSIONS An institutional protocol of early anatomic biventricular repair of double-outlet right ventricle in infants and neonates achieves excellent survival, making palliative operations unnecessary. Associated lesions should be repaired simultaneously. The complexity of these malformations requires a highly individualized and flexible surgical approach.
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Affiliation(s)
- C I Tchervenkov
- Department of Cardiovascular Surgery, Montreal Children's Hospital, Quebec, Canada
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Paquet M, Williams RL. Origin of the right subclavian artery from the right pulmonary artery in a newborn with complete transposition of the great arteries. Can J Cardiol 1994; 10:932-4. [PMID: 7954030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The clinical and angiographic features of a newborn with differential cyanosis between the right arm and the rest of the body are described. The embryology of the vascular anomalies and the hemodynamic mechanisms are discussed.
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Affiliation(s)
- M Paquet
- Division of Cardiology, Montreal Children's Hospital, Quebec
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Abstract
Supraventricular or ventricular ectopy has been reported in association with cardiac fibroma. We report two patients, one with acquired complete heart block and one with mixed ventricular and supraventricular arrhythmias associated with this rare tumor of the heart.
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Affiliation(s)
- M Filiatrault
- Department of Pediatrics (Division of Cardiology), Montreal Children's Hospital, Canada
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Paquet M, Béland MJ. [Transfemoral vein catheter occlusion of patent ductus arteriosus]. Arch Mal Coeur Vaiss 1991; 84:361-4. [PMID: 2048922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Between February 1988 and September 1989, 15 patients underwent closure of patent ductus arteriosus by the Rashkind technique modified by Mullins. The insertion of the occluder was achieved in all cases; however, in one patient, the prosthesis migrated to the abdominal aorta several hours after implantation. No other complications were observed. All patients were discharged from hospital under 24 hours after the procedure. The follow-up period ranges from 3 to 12 months. The rate of complete closure of the ductus was 50% 24 hours after implantation, 57% at 3 months, 66% at 6 months and 82% 12 months after the procedure. Our results suggest that the Rashkind technique for the closure of patent ductus arteriosus by the transvenous femoral approach is an effective and low risk procedure.
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Affiliation(s)
- M Paquet
- Service de cardiologie, hôpital de Montréal pour enfants, Québec, Canada
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Abstract
Seventy-four children aged 0.3 to 21.4 years (median 4.0) were followed echocardiographically on days 4, 7, 14 and 28 (+/- 2 days) after cardiac surgery to evaluate the incidence of postoperative pericardial effusion, to identify the patients at greatest risk of developing an effusion and to evaluate the use of aspirin as prophylaxis against pericardial effusion. Pericardial effusion was graded relative to the size of the aortic root from grade 0 (no effusion) to grade 5 (larger than the aortic root dimension). Patients were randomly divided into 2 groups: group 1 (32 patients) received aspirin 60 mg/kg/day for 7 days starting on the third postoperative day; group 2 (42 patients) received no aspirin. Forty-eight patients (65%) developed an effusion during the study period, 3 required pericardiocentesis and 1 died of tamponade. All patients with tamponade had a grade 4 effusion. Age or type of operation did not alter the cumulative incidence of significant effusion. No patient with a grade 0 effusion on the first echocardiogram developed a grade 4 or 5 effusion. Results in groups 1 and 2 were similar. Pericardial effusions are common in the first month after cardiac surgery. Patients with no effusion in the immediate postoperative period appear to be at lesser risk of developing a grade 4 effusion in the first month after operation. Finally, aspirin prophylaxis against postoperative pericardial effusions did not significantly alter the outcome in this small series of patients.
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Affiliation(s)
- M J Béland
- Department of Pediatrics, Montreal Children's Hospital, McGill University, Quebec, Canada
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Paquet M. [Support for persons caring for aged persons with loss of autonomy: a group intervention, an alternative? Presentation of a research project in the Lanaudiere region]. Sante Ment Que 1990; 15:246-9. [PMID: 2096973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Paquet M, Gibbons JE, Béland MJ. Transseptal catheterization of the left heart in infants and children: experience in a small volume catheterization laboratory. Can J Cardiol 1989; 5:287-90. [PMID: 2790574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
During a five-and-one-half year period, the transseptal technique was used for left heart catheterization in 37 patients with a variety of congenital heart disease. The age of the patients ranged from four months to 21 years and weights ranged from 6.6 to 65 kg. Access to the left heart cavities and ascending aorta was achieved in all but two patients. There were no complications. Even when used infrequently, the transseptal technique allows rapid and safe entry to the left heart cavities in infants and children.
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Affiliation(s)
- M Paquet
- Department of Pediatrics, Montreal Children's Hospital, Québec
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