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Turcu AF, Tezuka Y, Lim JS, Salman Z, Sehgal K, Liu H, Larose S, Parksook WW, Williams TA, Cohen DL, Wachtel H, Zhang J, Dorwal P, Satoh F, Yang J, Lacroix A, Reincke M, Giordano T, Udager A, Vaidya A, Rainey WE. Multifocal, Asymmetric Bilateral Primary Aldosteronism Cannot be Excluded by Strong Adrenal Vein Sampling Lateralization: An International Retrospective Cohort Study. Hypertension 2024; 81:604-613. [PMID: 38174562 PMCID: PMC10922262 DOI: 10.1161/hypertensionaha.123.21910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 12/16/2023] [Indexed: 01/05/2024]
Abstract
BACKGROUND Primary aldosteronism (PA) has been broadly dichotomized into unilateral and bilateral forms. Adrenal vein sampling (AVS) lateralization indices (LI) ≥2 to 4 are the standard-of-care to recommend unilateral adrenalectomy for presumed unilateral PA. We aimed to assess the rates and characteristics of residual PA after AVS-guided adrenalectomy. METHODS We conducted an international, retrospective, cohort study of patients with PA from 7 referral centers who underwent unilateral adrenalectomy based on LI≥4 on baseline and/or cosyntropin-stimulated AVS. Aldosterone synthase (CYP11B2) immunohistochemistry and next generation sequencing were performed on available formalin-fixed paraffin-embedded adrenal tissue. RESULTS The cohort included 283 patients who underwent AVS-guided adrenalectomy, followed for a median of 326 days postoperatively. Lack of PA cure was observed in 16% of consecutive patients, and in 22 patients with lateralized PA on both baseline and cosyntropin-stimulated AVS. Among patients with residual PA postoperatively, 73% had multiple CYP11B2 positive areas within the resected adrenal tissue (versus 23% in those cured), wherein CACNA1D mutations were most prevalent (63% versus 33% in those cured). In adjusted regression models, independent predictors of postoperative residual PA included Black versus White race (odds ratio, 5.10 [95% CI, 1.45-17.86]), AVS lateralization only at baseline (odds ratio, 8.93 [95% CI 3.00-26.32] versus both at baseline and after cosyntropin stimulation), and CT-AVS disagreement (odds ratio, 2.75 [95% CI, 1.20-6.31]). CONCLUSIONS Multifocal, asymmetrical bilateral PA is relatively common, and it cannot be excluded by robust AVS lateralization. Long-term postoperative monitoring should be routinely pursued, to identify residual PA and afford timely initiation of targeted medical therapy.
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Affiliation(s)
- Adina F. Turcu
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan, Ann Arbor, USA
| | - Yuta Tezuka
- Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Jung Soo Lim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju Severance Christian Hospital, Wonju, South Korea
| | - Zara Salman
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan, Ann Arbor, USA
| | - Kartik Sehgal
- Centre for Endocrinology and Metabolism, Department of Medicine, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Haiping Liu
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan, Ann Arbor, USA
| | - Stéphanie Larose
- Division of Endocrinology, Department of Medicine and Research Center, Centre hospitalier de l’Université de Montréal (CHUM), Montréal, Québec, Canada
| | - Wasita Warachit Parksook
- Center for Adrenal Disorders, Division of Endocrinology, Diabetes, and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Tracy Ann Williams
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, München, Germany
| | - Debbie L Cohen
- Renal-Electrolyte and Hypertension Division, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Heather Wachtel
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Jinghong Zhang
- Centre for Endocrinology and Metabolism, Department of Medicine, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Pranav Dorwal
- Department of Pathology, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Fumitoshi Satoh
- Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Jun Yang
- Centre for Endocrinology and Metabolism, Department of Medicine, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - André Lacroix
- Division of Endocrinology, Department of Medicine and Research Center, Centre hospitalier de l’Université de Montréal (CHUM), Montréal, Québec, Canada
| | - Martin Reincke
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, LMU München, München, Germany
| | - Tom Giordano
- Department of Pathology, University of Michigan, Ann Arbor, USA
| | - Aaron Udager
- Department of Pathology, University of Michigan, Ann Arbor, USA
| | - Anand Vaidya
- Center for Adrenal Disorders, Division of Endocrinology, Diabetes, and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - William E. Rainey
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, USA
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Younes N, Larose S, Bourdeau I, Therasse E, Lacroix A. Role of Adrenal Vein Sampling in Guiding Surgical Decision in Primary Aldosteronism. Exp Clin Endocrinol Diabetes 2023; 131:418-434. [PMID: 37567230 DOI: 10.1055/a-2106-4663] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/13/2023]
Abstract
Adrenal vein sampling (AVS) is recommended for subtyping primary aldosteronism (PA) to identify lateralized or bilateral sources of aldosterone excess, allowing for better decision-making in regard to medical or surgical management on a case-by-case basis. To date, no consensus exists on protocols to be used during AVS, especially concerning sampling techniques, the timing of sampling, and whether or not to use adrenocorticotropic hormone (ACTH) stimulation. Interpretation criteria for selectivity, lateralization, and contralateral suppression vary from one expert center to another, with some favoring strict cut-offs to others being more permissive. Clinical and biochemical post-operative outcomes can also be influenced by AVS criteria utilized to indicate surgical therapy.In this review, we reanalyze studies on AVS highlighting the recent pathological findings of frequent micronodular hyperplasia adjacent to a dominant aldosteronoma (APA) overlapping with bilateral idiopathic hyperaldosteronism (IHA) etiologies, as opposed to the less frequent unilateral single aldosteronoma. The variable expression of melanocortin type 2 receptors in the nodules and hyperplasia may explain the frequent discordance in lateralization ratios between unstimulated and ACTH- stimulated samples. We conclude that aldosterone values collected during simultaneous bilateral sampling, both at baseline and post-ACTH stimulation, are required to adequately evaluate selectivity, lateralization, and contralateral suppression during AVS, to better identify all patients with PA that can benefit from a surgical indication. Recommended cut-offs for each ratio are also presented.
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Affiliation(s)
- Nada Younes
- Division of Endocrinology, Department of Medicine and Research Center, Centre hospitalier de l'Université de Montréal (CHUM), Montréal, Québec, Canada
| | - Stéphanie Larose
- Division of Endocrinology, Department of Medicine and Research Center, Centre hospitalier de l'Université de Montréal (CHUM), Montréal, Québec, Canada
| | - Isabelle Bourdeau
- Division of Endocrinology, Department of Medicine and Research Center, Centre hospitalier de l'Université de Montréal (CHUM), Montréal, Québec, Canada
| | - Eric Therasse
- Department of Radiology, Centre de Recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Université de Montréal, Québec, Canada
| | - André Lacroix
- Division of Endocrinology, Department of Medicine and Research Center, Centre hospitalier de l'Université de Montréal (CHUM), Montréal, Québec, Canada
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3
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Larose S, Filliter C, Platt RW, Yu OHY, Filion KB. Long-acting insulin analogues and the risk of diabetic retinopathy among patients with type 2 diabetes: A population-based cohort study. Diabetes Obes Metab 2023. [PMID: 37165960 DOI: 10.1111/dom.15106] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/12/2023]
Abstract
AIM To determine whether the use of long-acting insulin analogues is associated with an increased risk of incident diabetic retinopathy (DR) among patients with type 2 diabetes. METHODS Using data from the Clinical Practice Research Datalink Aurum, this retrospective, population-based cohort study included patients with type 2 diabetes who initiated a long-acting insulin analogue (glargine, detemir, degludec) or Neutral Protamine Hagedorn (NPH) insulin. The primary outcome was incident DR. We used Cox proportional hazards models with inverse probability of treatment weighting to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident DR with insulin analogues versus NPH insulin. RESULTS There were 66 280 new users of long-acting insulin analogues and 66 173 new users of NPH insulin. The incidence rate of DR was 101.7 per 1000 person-years (95% CI, 98.7-104.8) for insulin analogues and 93.2 (95% CI, 90.0-96.5) per 1000 person-years for NPH insulin. Compared with the current use of NPH insulin, insulin analogues were not associated with the risk of incident DR (HR 1.04, 95% CI, 0.99-1.09). The adjusted HRs were 0.84 (95% CI, 0.66-1.07) for proliferative DR and 1.02 (95% CI, 0.97-1.08) for non-proliferative DR. CONCLUSIONS Compared with NPH insulin, long-acting insulin analogues were not associated with the risk of incident DR among patients with type 2 diabetes. This finding provides important reassurance regarding the safety of long-acting insulin analogues with respect to incident DR.
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Affiliation(s)
- Stéphanie Larose
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada
- Center for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada
| | - Christopher Filliter
- Center for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada
| | - Robert W Platt
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada
- Center for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada
- Department of Paediatrics, McGill University, Montreal, Quebec, Canada
| | - Oriana H Y Yu
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada
- Center for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada
- Division of Endocrinology, Jewish General Hospital, Montreal, Quebec, Canada
| | - Kristian B Filion
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada
- Center for Clinical Epidemiology, Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada
- Department of Medicine, McGill University, Montreal, Quebec, Canada
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Larose S, Rioux D, Albadine R, Lacroix A. Ectopic ACTH Cushing's syndrome caused by a large-cell neuroendocrine lung carcinoma responding to desmopressin. Endocr Oncol 2023; 3:e230002. [PMID: 37434650 PMCID: PMC10305561 DOI: 10.1530/eo-23-0002] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 04/27/2023] [Indexed: 07/13/2023]
Abstract
Ectopic adrenocorticotrophic hormone (ACTH) secretion (EAS) is a rare cause of ACTH-dependent Cushing's syndrome (CS), most often caused by a thoracic neuroendocrine tumor (NET). Large-cell neuroendocrine carcinomas (LCNEC) with EAS are rare and usually present a more severe ACTH secretion and hypercortisolism. We report a 44-year-old non-smoker man, who presented clinical and biochemical evidence of ACTH-dependent CS. Desmopressin 10 μg i.v. produced a 157% increase in ACTH and a 25% increase in cortisol from baseline; there was no stimulation of ACTH or cortisol during the corticotropin-releasing hormone (CRH) test and no suppression with high dose dexamethasone. Pituitary MRI identified a 5 mm lesion, but inferior petrosal venous sinus sampling under desmopressin did not identify a central ACTH source. Thorax and abdominal imaging identified a left lung micronodule. Surgery confirmed a lung LCNEC with strongly positive ACTH immunohistochemistry (IHC) in the primary and lymph node metastasis. The patient was in CS remission after surgery and adjuvant chemotherapy but developed a recurrence 9.5 years later, with LCNEC pulmonary left hilar metastases, ectopic CS, and positive ACTH IHC. This is the first report of LCNEC, with morphologic feature of carcinoid tumor of the lung with ectopic ACTH stimulated by desmopressin. Long delay prior to metastatic recurrence indicates relatively indolent NET. This case report indicates that response to desmopressin, which usually occurs in Cushing's disease or benign NETs, can occur in malignant LCNEC.
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Affiliation(s)
- Stéphanie Larose
- Division of Endocrinology, Department of Medicine, Centre hospitalier de l’Université de Montréal (CHUM), Université de Montréal, Montréal, QC, Canada
| | - Dany Rioux
- Division of Endocrinology, Department of Medicine, Centre hospitalier universitaire régional, Trois-Rivières, QC, Canada
| | - Roula Albadine
- Department of Pathology, Centre hospitalier de l’Université de Montréal, Université de Montréal (CHUM), Université de Montréal, Montréal, QC, Canada, Montréal, QC, Canada
| | - André Lacroix
- Division of Endocrinology, Department of Medicine, Centre hospitalier de l’Université de Montréal (CHUM), Université de Montréal, Montréal, QC, Canada
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Larose S, Rabasa-Lhoret R, Roy-Fleming A, Suppère C, Tagougui S, Messier V, Taleb N. Changes in Accuracy of Continuous Glucose Monitoring Using Dexcom G4 Platinum Over the Course of Moderate Intensity Aerobic Exercise in Type 1 Diabetes. Diabetes Technol Ther 2019; 21:364-369. [PMID: 31045433 DOI: 10.1089/dia.2018.0400] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Continuous glucose monitoring (CGM) systems help diabetes management in patients with type 1 diabetes (T1D) but could have lower accuracy during exercise. We aim to evaluate the dynamics of CGM accuracy during exercise in patients with T1D. Secondary analysis of data was carried out on 22 patients with T1D (glycated hemoglobin [HbA1c]: 7.3% ± 1.0%, diabetes duration: 23 ± 13 years), who did three exercise sessions (45 min at 60% VO2max on an ergocycle, 3 h postmeal) with paired Dexcom G4 Platinum, and capillary glucose values that were collected every 5 min. Dexcom accuracy was evaluated using sensor bias (SB) and absolute relative difference (ARD). For dynamics of SB analysis, data pairs following hypoglycemia correction were excluded. The analyzed data included 792 pairs (594 during 66 exercise sessions, 198 at rest before exercise). Median ARD was 8.44 (5.35-12.13)% at rest and increased to 16.77 (10.75-26.72)% during exercise (P < 0.001). During exercise, mean SB values evolved from T0 minutes = 5.95 ± 16.04 mg/dL (exercise start); T5 = 9.55 ± 16.40; T10 = 13.51 ± 18.02; T15 = 15.32 ± 20.36; T20 = 17.30 ± 18.92; T25 = 19.46 ± 17.48; T30 = 21.08 ± 19.64; T35 = 19.10 ± 20.36; T40 = 19.82 ± 20.18; and T45 = 18.02 ± 20.90 (exercise end). CGM overestimated capillary at a mean SB of 14.23 ± 16.76 mg/dL over the whole exercise session. CGM accuracy decreased during moderate aerobic exercise as previously described. However, the trend to overestimate capillary glucose was maintained at relatively stable values within 15 min of exercise initiation, which could help patients in their clinical decisions. Similar analyses would be needed for other types of exercise.
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Affiliation(s)
- Stéphanie Larose
- 1 Metabolic Diseases, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada
| | - Rémi Rabasa-Lhoret
- 1 Metabolic Diseases, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada
- 2 Nutrition Department, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
- 3 Montreal Diabetes Research Center and Endocrinology Division, Montréal, Québec, Canada
| | - Amélie Roy-Fleming
- 1 Metabolic Diseases, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada
| | - Corinne Suppère
- 1 Metabolic Diseases, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada
| | - Sémah Tagougui
- 1 Metabolic Diseases, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada
| | - Virginie Messier
- 1 Metabolic Diseases, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada
| | - Nadine Taleb
- 1 Metabolic Diseases, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada
- 4 Division of Biomedical Sciences, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
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Abstract
The purpose of this study was to test the hypothesis that computer games may be an efficient therapeutic tool in a cognitive rehabilitation program. 60 subjects who showed attention difficulties with or without cerebral dysfunctions participated in a 12-hr. training program based on intensive use of a computer game. Analyses show improvement for the experimental group on scanning and tracking variables, notwithstanding the nature of their particular dysfunctions. Recommendations are presented regarding the nature and content of the cognitive tasks in a rehabilitation program.
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Affiliation(s)
- S Larose
- Ecole de Psychologie, Pavillon F-A. Savard, Université Laval, Sainte-Foy, Québec, Canada
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Larose S, Bondaz L, Mermejo LM, Latour M, Prosmanne O, Bourdeau I, Lacroix A. Coexistence of Myelolipoma and Primary Bilateral Macronodular Adrenal Hyperplasia With GIP-Dependent Cushing's Syndrome. Front Endocrinol (Lausanne) 2019; 10:618. [PMID: 31572300 PMCID: PMC6749096 DOI: 10.3389/fendo.2019.00618] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 08/27/2019] [Indexed: 12/14/2022] Open
Abstract
Introduction: Adrenal myelolipomas are usually isolated benign adrenal lesions, but can be adjacent to steroid-secreting adrenocortical tumors. We studied the aberrant regulation of cortisol secretion in a 61 year-old woman with combined bilateral myelolipomas and primary bilateral macronodular adrenal hyperplasia (BMAH) causing Cushing's syndrome. Materials and Methods: Cortisol response was measured during in vivo tests that transiently modulated the levels of ligands for potential aberrant receptors, including GIP. Response to medical therapies decreasing GIP was monitored. Expression of ACTH and of GIP receptors were examined in resected adrenal tissues by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR). Results: In vivo, cortisol increased in response to mixed meals (+353%), oral 75 g glucose (+71%), GIP infusion (+416%), and hLH IV (+243%). Suppression of GIP by pasireotide improved cortisol secretion but produced hyperglycemia. The left adrenal was predominantly composed of myelolipoma and strands of BMAH, while the right was mainly composed of BMAH with some foci of myelolipoma on pathology. No ACTH was detectable by immunohistochemistry in BMAH or myelolipomas tissue. Ectopic GIP receptor was confirmed by RT-PCR and immunohistochemistry in BMAH tissues but not in the myelolipomas. No germline mutations were identified in the ARMC5 gene of the patient's leucocyte DNA. Conclusion: This is the first report of interspersed myelolipoma and BMAH with GIP-dependent Cushing's syndrome. In contrast with the BMAH tissues, myelolipoma tissue did not express specific GIP receptors. The potential mechanisms responsible for the interspersed growth of those two lesions remain to be identified.
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Affiliation(s)
- Stéphanie Larose
- Division of Endocrinology, Department of Medicine, Centre Hospitalier de L'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Louis Bondaz
- Division of Endocrinology, Department of Medicine, Centre Hospitalier de L'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Livia M. Mermejo
- Division of Endocrinology, Department of Medicine, Centre Hospitalier de L'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Mathieu Latour
- Department of Pathology, Centre Hospitalier de L'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Odile Prosmanne
- Department of Radiology, Centre Hospitalier de L'Université de Montréal (CHUM), Montreal, QC, Canada
| | - Isabelle Bourdeau
- Division of Endocrinology, Department of Medicine, Centre Hospitalier de L'Université de Montréal (CHUM), Montreal, QC, Canada
| | - André Lacroix
- Division of Endocrinology, Department of Medicine, Centre Hospitalier de L'Université de Montréal (CHUM), Montreal, QC, Canada
- *Correspondence: André Lacroix
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Pouliot E, Larose S, Gagnon J, Belanger RE. 114: Use of Soft Tissue Neck Radiographs in Pediatric Acute Airway Obstructions: Current Perspective. Paediatr Child Health 2014. [DOI: 10.1093/pch/19.6.e35-112] [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: 11/14/2022] Open
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Pouliot E, Larose S, Gagnon J, Bélanger RE. 193: Identifying Radiologic Signs of Life-Threatening Causes of Acute Upper Airway Obstruction in Children: Not That Easy! Paediatr Child Health 2014. [DOI: 10.1093/pch/19.6.e35-188] [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: 11/12/2022] Open
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Dionne I, Larose S, Dandjinou AT, Abou Elela S, Wellinger RJ. Cell cycle-dependent transcription factors control the expression of yeast telomerase RNA. RNA 2013; 19:992-1002. [PMID: 23690630 PMCID: PMC3683933 DOI: 10.1261/rna.037663.112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 04/12/2013] [Indexed: 06/02/2023]
Abstract
Telomerase is a specialized ribonucleoprotein that adds repeated DNA sequences to the ends of eukaryotic chromosomes to preserve genome integrity. Some secondary structure features of the telomerase RNA are very well conserved, and it serves as a central scaffold for the binding of associated proteins. The Saccharomyces cerevisiae telomerase RNA, TLC1, is found in very low copy number in the cell and is the limiting component of the known telomerase holoenzyme constituents. The reasons for this low abundance are unclear, but given that the RNA is very stable, transcriptional control mechanisms must be extremely important. Here we define the sequences forming the TLC1 promoter and identify the elements required for its low expression level, including enhancer and repressor elements. Within an enhancer element, we found consensus sites for Mbp1/Swi4 association, and chromatin immunoprecipitation (ChIP) assays confirmed the binding of Mbp1 and Swi4 to these sites of the TLC1 promoter. Furthermore, the enhancer element conferred cell cycle-dependent regulation to a reporter gene, and mutations in the Mbp1/Swi4 binding sites affected the levels of telomerase RNA and telomere length. Finally, ChIP experiments using a TLC1 RNA-binding protein as target showed cell cycle-dependent transcription of the TLC1 gene. These results indicate that the budding yeast TLC1 RNA is transcribed in a cell cycle-dependent fashion late in G1 and may be part of the S phase-regulated group of genes involved in DNA replication.
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Noël JF, Larose S, Abou Elela S, Wellinger RJ. Budding yeast telomerase RNA transcription termination is dictated by the Nrd1/Nab3 non-coding RNA termination pathway. Nucleic Acids Res 2012; 40:5625-36. [PMID: 22379137 PMCID: PMC3384322 DOI: 10.1093/nar/gks200] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [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] [Indexed: 11/15/2022] Open
Abstract
The RNA component of budding yeast telomerase (Tlc1) occurs in two forms, a non-polyadenylated form found in functional telomerase and a rare polyadenylated version with unknown function. Previous work suggested that the functional Tlc1 polyA- RNA is processed from the polyA+ form, but the mechanisms regulating its transcription termination and 3'-end formation remained unclear. Here we examined transcription termination of Tlc1 RNA in the sequences 3' of the TLC1 gene and relate it to telomere maintenance. Strikingly, disruption of all probable or cryptic polyadenylation signals near the 3'-end blocked the accumulation of the previously reported polyA+ RNA without affecting the level, function or specific 3' nucleotide of the mature polyA- form. A genetic approach analysing TLC1 3'-end sequences revealed that transcription terminates upstream of the polyadenylation sites. Furthermore, the results also demonstrate that the function of this Tlc1 terminator depends on the Nrd1/Nab3 transcription termination pathway. The data thus show that transcription termination of the budding yeast telomerase RNA occurs as that of snRNAs and Tlc1 functions in telomere maintenance are not strictly dependent on a polyadenylated precursor, even if the polyA+ form can serve as intermediate in a redundant termination/maturation pathway.
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Affiliation(s)
- Jean-François Noël
- RNA Group, Department of Microbiology and Infectious Diseases, Faculty of Medicine, Université de Sherbrooke, 3001, 12e Ave Nord, Sherbrooke, Quebec, J1H 5N4, Canada
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Habersaat S, Tessier R, Larose S, Nadeau L, Tarabulsy G, Moss E, Pierrehumbert B. Adoption, adolescence et difficultés de comportement : quels facteurs de risque ? Annales Médico-psychologiques, revue psychiatrique 2010. [DOI: 10.1016/j.amp.2009.03.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
In bakers' yeast, in vivo telomerase activity requires a ribonucleoprotein (RNP) complex with at least four associated proteins (Est2p, Est1p, Est3p, and Cdc13p) and one RNA species (Tlc1). The function of telomerase in maintaining chromosome ends, called telomeres, is tightly regulated and linked to the cell cycle. However, the mechanisms that regulate the expression of individual components of telomerase are poorly understood. Here we report that yeast RNase III (Rnt1p), a double-stranded RNA-specific endoribonuclease, regulates the expression of telomerase subunits and is required for maintaining normal telomere length. Deletion or inactivation of RNT1 induced the expression of Est1, Est2, Est3, and Tlc1 RNAs and increased telomerase activity, leading to elongation of telomeric repeat tracts. In silico analysis of the different RNAs coding for the telomerase subunits revealed a canonical Rnt1p cleavage site near the 3' end of Est1 mRNA. This predicted structure was cleaved by Rnt1p and its disruption abolished cleavage in vitro. Mutation of the Rnt1p cleavage signal in vivo impaired the cell cycle-dependent degradation of Est1 mRNA without affecting its steady-state level. These results reveal a new mechanism that influences telomeres length by controlling the expression of the telomerase subunits.
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Affiliation(s)
- Stéphanie Larose
- RNA Group, Département de Microbiologie et d'Infectiologie, Facultéde Médecine, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada
| | - Nancy Laterreur
- RNA Group, Département de Microbiologie et d'Infectiologie, Facultéde Médecine, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada
| | - Ghada Ghazal
- RNA Group, Département de Microbiologie et d'Infectiologie, Facultéde Médecine, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada
| | - Jules Gagnon
- RNA Group, Département de Microbiologie et d'Infectiologie, Facultéde Médecine, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada
| | - Raymund J Wellinger
- RNA Group, Département de Microbiologie et d'Infectiologie, Facultéde Médecine, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada
| | - Sherif Abou Elela
- RNA Group, Département de Microbiologie et d'Infectiologie, Facultéde Médecine, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada.
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Dandjinou AT, Lévesque N, Larose S, Lucier JF, Abou Elela S, Wellinger RJ. A Phylogenetically Based Secondary Structure for the Yeast Telomerase RNA. Curr Biol 2004; 14:1148-58. [PMID: 15242611 DOI: 10.1016/j.cub.2004.05.054] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2004] [Revised: 05/20/2004] [Accepted: 05/21/2004] [Indexed: 11/21/2022]
Abstract
BACKGROUND Telomerase is a ribonucleoprotein complex whose RNA moiety dictates the addition of specific simple sequences onto chromosomes ends. While relevant for certain human genetic diseases, the contribution of the essential telomerase RNA to RNP assembly still remains unclear. Phylogenetic analyses of vertebrate and ciliate telomerase RNAs revealed conserved elements that potentially organize protein subunits for RNP function. In contrast, the yeast telomerase RNA could not be fitted to any known structural model, and the limited number of known sequences from Saccharomyces species did not permit the prediction of a yeast specific conserved structure. RESULTS We cloned and analyzed the complete telomerase RNA loci (TLC1) from all known Saccharomyces species belonging to the "sensu stricto" group. Complementation analyses in S. cerevisiae and end mappings of mature RNAs ensured the relevance of the cloned sequences. By using phylogenetic comparative analysis coupled with in vitro enzymatic probing, we derived a secondary structure prediction of the Saccharomyces cerevisiae TLC1 RNA. This conserved secondary structure prediction includes a central domain that is likely to orchestrate DNA synthesis and at least two accessory domains important for RNA stability and telomerase recruitment. The structure also reveals a potential tertiary interaction between two loops in the central core. CONCLUSIONS The predicted secondary structure of the TLC1 RNA of S. cerevisiae reveals a distinct folding pattern featuring well-separated but conserved functional elements. The predicted structure now allows for a detailed and rationally designed study to the structure-function relationships within the telomerase RNP-complex in a genetically tractable system.
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Affiliation(s)
- Alain T Dandjinou
- Groupe ARN/RNA Group, Department of Microbiology and Infectious Diseases, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue N., Sherbrooke, QC J1H 5N4, Canada
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15
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Catala M, Lamontagne B, Larose S, Ghazal G, Elela SA. Cell cycle-dependent nuclear localization of yeast RNase III is required for efficient cell division. Mol Biol Cell 2004; 15:3015-30. [PMID: 15090619 PMCID: PMC452560 DOI: 10.1091/mbc.e04-03-0183] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [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: 11/11/2022] Open
Abstract
Members of the double-stranded RNA-specific ribonuclease III (RNase III) family were shown to affect cell division and chromosome segregation, presumably through an RNA interference-dependent mechanism. Here, we show that in Saccharomyces cerevisiae, where the RNA interference machinery is not conserved, an orthologue of RNase III (Rnt1p) is required for progression of the cell cycle and nuclear division. The deletion of Rnt1p delayed cells in both G1 and G2/M phases of the cell cycle. Nuclear division and positioning at the bud neck were also impaired in Deltarnt1 cells. The cell cycle defects were restored by the expression of catalytically inactive Rnt1p, indicating that RNA cleavage is not essential for cell cycle progression. Rnt1p was found to exit from the nucleolus to the nucleoplasm in the G2/M phase, and perturbation of its localization pattern delayed the progression of cell division. A single mutation in the Rnt1p N-terminal domain prevented its accumulation in the nucleoplasm and slowed exit from mitosis without any detectable effects on RNA processing. Together, the data reveal a new role for a class II RNase III in the cell cycle and suggest that at least some members of the RNase III family possess catalysis-independent functions.
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Affiliation(s)
- Mathieu Catala
- RNA Group/Groupe ARN, Département de Microbiologie et d'Infectiologie, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, Québec, Canada.
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16
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Lamontagne B, Larose S, Boulanger J, Elela SA. The RNase III family: a conserved structure and expanding functions in eukaryotic dsRNA metabolism. Curr Issues Mol Biol 2001; 3:71-8. [PMID: 11719970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
The last few years have witnessed the appreciation of dsRNA as a regulator of gene expression, a potential antiviral agent, and a tumor suppressor. However, in spite of these clear effects on the cell function, the mechanism that controls dsRNA maturation and stability remains unknown. Recently, the discovery of eukaryotic orthologues of the bacterial dsRNA specific ribonuclease III (RNase III) suggested a central role for these enzymes in the regulation of dsRNA and eukaryotic RNA metabolism in general. This article reviews the structure-function features of the eukaryotic RNase III family and their roles in dsRNA metabolism with an emphasis on the yeast RNase III. Yeast RNase III is involved in the maturation of the majority of snRNAs, snoRNAs, and rRNA. In addition, perturbation of the expression level of yeast RNase III alters meiosis and causes sterility. These basic functions of the yeast RNase III appear to be widely conserved which makes it a good model to understand the importance of eukaryotic dsRNA metabolism.
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Affiliation(s)
- B Lamontagne
- Département de Microbiologie et d'Infectiologie, Faculté de Médecine, Université de Sherbrooke, Québec, Canada
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Abstract
This study examined the mediational link between attachment state of mind, social support processes and personal adjustment. The Adult Attachment Interview was administered to 62 adolescents during their college transition. At the end of high school and during their first semester in college, students completed questionnaires pertaining to primary and secondary appraisals; coping and personal adjustment were assessed through self- and peer-report questionnaires. A dismissing tendency was related to difficulty in getting assistance from peers and teachers and to peer-reported withdrawal. A preoccupied tendency was associated with stress regarding the transition, distrust in potential supporters, difficulty seeking help from teachers, and loneliness. Moreover, stress, distrust and help-seeking mediated the link between preoccupied attachment and loneliness, whereas the relation between dismissing attachment and withdrawal was not mediated by help-seeking. Cognitive and behavioral attachment processes are discussed.
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Affiliation(s)
- S Larose
- Département d'etudes sur l'enseignement et l'apprentissage, Faculté des Sciences de l'éducation, Université Laval, Quebec, Canada.
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18
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Poirier M, Larose S, Ste-Marie F, Rosenberg L, Ritzhaupt B. [Splendor and misery in the local organization of mental health: a look at the field]. Can J Commun Ment Health 2000; 18:113-29. [PMID: 10947635] [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: 02/17/2023]
Abstract
Collaboration among public and community resources (or concentration as it is referred to in French) is a practice much favoured by governments for ideological and economic reasons. But if administrative collaboration is relatively easy to set up, what about collaboration among front-line field workers? What are the ingredients likely to engender true collaboration among practitioners, and what obstacles do they meet with on a practical day-to-day level? Experience acquired in the West Island area of greater Montreal has led us to the conclusion that many issues need to be examined and understood: the difficulty of reconciling client empowerment with treatment; the difficulty of harmonizing the values and convictions prevailing in institutional and community-based networks; the tendency for practitioners to keep clienteles for themselves within a treatment environment. Despite these difficulties, it is evident that there will be a trend towards increasing collaboration where clienteles are growing and where problems are becoming more complex.
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Affiliation(s)
- M Poirier
- Télé-université, Université du Québec
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19
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Abstract
This study examined whether adolescents' perceptions of attachment security and behavioral and psychological control as experienced in family and mentoring contexts are predictive of their adjustment to college. One hundred fifty-eight academically at-risk adolescents (63 men and 95 women, 16-20 years old) completed questionnaires twice during their first semester: before and after they participated in a mentoring program. Analyses yielded 4 findings: (a) Paternal control was predictive of adolescent adjustment to college; (b) above and beyond perceptions of parental attachment and control, perception of a secure relationship with a mentor was predictive of adolescent adjustment; (c) this relationship was found to be stronger for adolescents who reported having high levels of security in the relationship with their mother; and (d) psychological control by both parents appeared to be a significant determinant of academic achievement.
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Affiliation(s)
- N Soucy
- Département d'Etudes sur l'Enseignement et l'Apprentissage, Faculté des Sciences de l'Education, Université Laval, Quebec, Canada
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Poirier M, Ritzhaupt B, Larose S, Chartrand D. [Case management: Montreal's west end model.]. Sante Ment Que 1998; 23:93-118. [PMID: 18253554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Socio-economic imperatives as well as the necessity to return a clientele in the past institutionalized for long periods of time in their own milieu have contributed to the emergence of new practices. Case management allows to intervene by involving natural and professional networks of support. Various models of case management exist but are often difficult to implement or manage. The model developed in Montreal's west end proposes a flexible, open and decentralized management, gives an important place to the client, and is characterized by the collaboration of all partners.
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Abstract
One hundred and eighty-seven adolescents referred to outpatient and residential services in three Canadian cities were assessed for lifetime suicidal ideation and attempt, and administered the Parental Bonding Instrument (PBI). Suicidal adolescents of both genders reported lower care and higher over-protection in relation to their mothers than non-suicidal subjects, and female subjects reported this pattern for their fathers as well. Male subjects did not show clear differentiation between groups on PBI ratings for their fathers. Mean PBI scores for female subjects indicated subjects with no suicidal ideation, those with suicidal ideation only, and those having made suicide attempts to be on a continuum, but findings for males did not. The findings extend previous reports of higher "affectionless control" in suicidal adults, but suggest that this pattern may be stronger in females than males, and that maternal influences may be stronger than paternal influences.
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Affiliation(s)
- K S Adam
- Department of Psychiatry, McMaster University Health Sciences Centre, Hamilton, Canada
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23
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Abstract
The purpose of this study was to test the hypothesis that computer games may be an efficient therapeutic tool in a cognitive rehabilitation program. 60 subjects who showed attention difficulties with or without cerebral dysfunctions participated in a 12-hr. training program based on intensive use of a computer game. Analyses show improvement for the experimental group on scanning and tracking variables, notwithstanding the nature of their particular dysfunctions. Recommendations are presented regarding the nature and content of the cognitive tasks in a rehabilitation program.
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Affiliation(s)
- S Larose
- Ecole de Psychologie, Pavillon F-A. Savard, Université Laval, Sainte-Foy, Québec, Canada
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