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Trudel-Ferland M, Levasseur M, Goulet-Beaulieu V, Jubinville E, Hamon F, Jean J. Concentration of foodborne viruses eluted from fresh and frozen produce: Applicability of ultrafiltration. Int J Food Microbiol 2024; 416:110687. [PMID: 38554558 DOI: 10.1016/j.ijfoodmicro.2024.110687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 03/21/2024] [Accepted: 03/26/2024] [Indexed: 04/01/2024]
Abstract
Foodborne illnesses involving raw and minimally processed foods are often caused by human noroviruses (HuNoV) and hepatitis A virus (HAV). Since food is contaminated usually with small numbers of virions, these must be eluted from the food surface and then concentrated for detection. The objective of this study was to optimize an ultrafiltration (UF) concentration method for HAV and HuNoVs present on various fresh and frozen produce. The detection range of the optimized method and its applicability to different food matrices was compared to the reference method ISO 15216-1:2017. Strawberry, raspberry, blackberry, lettuce, and green onion (25 g) were contaminated with HAV, HuNoV GI.7 and HuNoV GII.4 and then recovered therefrom by elution. A commercial benchtop UF device was used for the concentration step. Viral RNA was extracted and detected by RT-qPCR. From fresh strawberries, recovery of HAV loaded at 104 genome copies per sample was 30 ± 13 %, elution time had no significant impact, and UF membrane with an 80-100 kDa cut-off in combination with Tris-glycine elution buffer at pH 9.5 was found optimal. At lower copy numbers on fresh strawberry, at least 1 log lower numbers of HuNoV were detectable by the UF method (103 vs 104 GII.4 copies/sample and 101 vs 103 GI.7 copies/sample), while HAV was detected at 101 genome copies/sample by both methods. Except on raspberry, the UF method was usually equivalent to the ISO method regardless of the virus tested. The UF method makes rapid viral concentration possible, while supporting the filtration of large volume of sample. With fewer steps and shorter analysis time than the ISO method, this method could be suitable for routine analysis of viruses throughout the food production and surveillance chain.
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Affiliation(s)
- Mathilde Trudel-Ferland
- Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec City, QC, Canada
| | - Marianne Levasseur
- Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec City, QC, Canada
| | - Valérie Goulet-Beaulieu
- Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec City, QC, Canada
| | - Eric Jubinville
- Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec City, QC, Canada
| | | | - Julie Jean
- Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec City, QC, Canada.
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Pageau G, Levasseur M, Paniconi T, Jubinville E, Goulet-Beaulieu V, Boivin G, Jean J. The possibility of spreading herpes simplex virus type 1 via food handling and sharing. J Appl Microbiol 2023; 134:lxad224. [PMID: 37827542 DOI: 10.1093/jambio/lxad224] [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: 06/01/2023] [Revised: 08/11/2023] [Accepted: 10/11/2023] [Indexed: 10/14/2023]
Abstract
AIMS Herpes simplex virus type 1 (HSV-1) is an enveloped virus that causes recurrent and incurable diseases in 67% of the world population. Although it is not listed as a foodborne virus, some studies have shown that it can be recovered from surfaces as well as food. METHODS AND RESULTS We investigated its persistence at -20°C, 4°C, 20°C, or 37°C for up to 7 days on stainless steel, aluminum, glass, polypropylene, cheddar cheese, sliced almond, and apple skin and in cola soft drink, orange juice, coffee, and milk, as well as its transferability from stainless steel to dry or moistened nitrile or latex gloves over time at typical ambient temperatures. Based on the plaque assay on Vero cells, HSV-1 persisted at least 24 h on all surfaces and at least 1 h on food matrices but was inactivated quickly in cola soft drink. Temperature and pH affected HSV-1 infectivity. Transfer of HSV-1 at a contact pressure of 1 kg cm2-1 for 10 s occurred only on latex, especially moistened. CONCLUSIONS Our data on the persistence of HSV-1 on food-related surfaces suggest that some risk may be associated with sharing foods with infected carriers.
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Affiliation(s)
- Gabrielle Pageau
- Department of Food Sciences, Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec G1V 0A6, Canada
| | - Marianne Levasseur
- Department of Food Sciences, Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec G1V 0A6, Canada
| | - Teresa Paniconi
- Department of Food Sciences, Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec G1V 0A6, Canada
| | - Eric Jubinville
- Department of Food Sciences, Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec G1V 0A6, Canada
| | - Valérie Goulet-Beaulieu
- Department of Food Sciences, Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec G1V 0A6, Canada
| | - Guy Boivin
- Research Center in Infectious Diseases of the CHUQ-CHUL and Laval University, Quebec City, Quebec G1V 4G2, Canada
| | - Julie Jean
- Department of Food Sciences, Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec G1V 0A6, Canada
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3
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Lagueux É, Masse J, Levasseur M, Pagé R, Dépelteau A, Lévesque MH, Tousignant-Laflamme Y, Pinard AM. Pilot Study of French-Canadian Lifestyle Redesign ® for Chronic Pain Management. OTJR (Thorofare N J) 2021; 41:80-89. [PMID: 33393417 DOI: 10.1177/1539449220982908] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
As chronic pain (CP) interferes with an individual's lifestyle by limiting meaningful activities and health-related quality of life (HRQoL), occupational therapy (OT) plays an important role in CP management interventions. This pilot study aimed to explore the influence of a 13-week French-Canadian Lifestyle Redesign® for CP. A mixed-methods research design including a preexperimental quantitative component pre-/posttest was used with 15 participants with fibromyalgia. Although pain remained unchanged after the intervention, improvements were observed in participants' engagement in meaningful activities (p < .01), life balance (p < .01), mental components of HRQoL (p < .01), depressive symptoms (p = .047), and pain self-efficacy (p < .01). After the intervention, phone interviews (n = 6) highlighted the participants' appreciation of the focus being placed on their daily routines and the development of a sense of belonging throughout the intervention. This study suggests the potential feasibility and benefits of an occupation-based approach in CP management.
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Affiliation(s)
- É Lagueux
- Université de Sherbrooke, Quebec, Canada.,Research Center of the Centre Hospitalier Universitaire de Sherbrooke, Quebec, Canada
| | - J Masse
- Université de Montréal, Quebec, Canada
| | | | - R Pagé
- Université de Sherbrooke, Quebec, Canada
| | | | | | - Y Tousignant-Laflamme
- Université de Sherbrooke, Quebec, Canada.,Research Center of the Centre Hospitalier Universitaire de Sherbrooke, Quebec, Canada
| | - A-M Pinard
- Université Laval, Quebec City, Quebec, Canada
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Maitre I, Roger A, Lesourd B, Sulmont-Rossé C, Corbière T, Martin M, Levasseur M, Van Wymelbeke V. À domicile : comment accompagner les aidants pour mieux nourrir les aidés ? NUTR CLIN METAB 2020. [DOI: 10.1016/j.nupar.2020.02.359] [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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Provencher V, Carbonneau H, Levasseur M, Poulin V, Filiatrault J, Giroux D, Filion-Trudeau M. Exploring the Impact of a New Intervention to Increase Participation of Frail Older Adults in Meaningful Leisure Activities. Activities, Adaptation & Aging 2017. [DOI: 10.1080/01924788.2017.1376176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- V. Provencher
- Faculty of Medicine and Health Sciences, School of Rehabilitation, Université de Sherbrooke, Sherbrooke, QC, Canada
- Centre de recherche sur le vieillissement, Sherbrooke, Trois-Rivières, QC, Canada
| | - H. Carbonneau
- Department of Studies in Leisure, Culture and Tourism, Université du Québec à Trois-Rivières, QC, Canada
| | - M. Levasseur
- Faculty of Medicine and Health Sciences, School of Rehabilitation, Université de Sherbrooke, Sherbrooke, QC, Canada
- Centre de recherche sur le vieillissement, Sherbrooke, Trois-Rivières, QC, Canada
| | - V. Poulin
- Centre interdisciplinaire de recherche en réadaptation et intégration sociale, Québec City, QC, Canada
| | - J. Filiatrault
- Faculty of Medicine, Department of Rehabilitation, Université de Montréal, Montrèal, QC, Canada
- Centre de recherche de l’Institut universitaire de gériatrie de Montréal, Montrèal, QC, Canada
| | - D. Giroux
- Faculty of Medicine, Department of Rehabilitation, Université Laval, Québec City, QC, Canada
- CHU de Québec, Centre d’excellence sur le vieillissement, Quèbec City, QC, Canada
| | - M. Filion-Trudeau
- Faculty of Medicine, Department of Rehabilitation, Université Laval, Québec City, QC, Canada
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Levasseur M, Lévesque M, Beaudry M, Lariviere N, Filiatrault J, Parisien M, Couturier Y, Champoux N. IMPACTS OF THE FRENCH LIFESTYLE REDESIGN®, A PREVENTIVE OCCUPATIONAL THERAPY INTERVENTION. Innov Aging 2017. [DOI: 10.1093/geroni/igx004.3270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- M. Levasseur
- Université de Sherbrooke, Sherbrooke, Quebec, Canada,
- Research centre on aging, Sherbrooke, Quebec, Canada,
| | - M. Lévesque
- Université de Sherbrooke, Sherbrooke, Quebec, Canada,
- Research centre on aging, Sherbrooke, Quebec, Canada,
| | - M. Beaudry
- Research centre on aging, Sherbrooke, Quebec, Canada,
| | - N. Lariviere
- Université de Sherbrooke, Sherbrooke, Quebec, Canada,
| | | | - M. Parisien
- Centre de réadaptation en déficience physique-Institut universitaire, Monréal, Quebec, Canada
| | - Y. Couturier
- Université de Sherbrooke, Sherbrooke, Quebec, Canada,
- Research centre on aging, Sherbrooke, Quebec, Canada,
| | - N. Champoux
- Université de Montréal, Montréal, Quebec, Canada,
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7
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Levasseur M, Coallier J, Gabaude C, Beaudry M, Bedard M, St-Pierre C. UNDERSTANDING THE USE OF COMPENSATORY STRATEGIES TO ENHANCE OLDER DRIVERS’ MOBILITY. Innov Aging 2017. [DOI: 10.1093/geroni/igx004.3175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- M. Levasseur
- Universit de Sherbrooke, Sherbrooke, Quebec, Canada,
| | - J. Coallier
- Universit de Sherbrooke, Sherbrooke, Quebec, Canada,
| | - C. Gabaude
- Institut français des sciences et technologies des transports, de l’aménagement et des réseaux, Bron, France,
| | - M. Beaudry
- Universit de Sherbrooke, Sherbrooke, Quebec, Canada,
| | - M. Bedard
- Lakehead University, Tunderbay, Ontario, Canada
| | - C. St-Pierre
- Universit de Sherbrooke, Sherbrooke, Quebec, Canada,
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Créange A, Serre I, Levasseur M, Audry D, Nineb A, Boërio D, Moreau T, Maison P. Walking capacities in multiple sclerosis measured by global positioning system odometer. Mult Scler 2017; 13:220-3. [PMID: 17439888 DOI: 10.1177/1352458506070667] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [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: 11/15/2022]
Abstract
We used a global positioning satellite technology odometer to determine the maximum objective walking distance capacity (MOWD) of patients with multiple sclerosis (MS). The MOWD correlated with Expanded Disability Status Scale (EDSS) score (r2 =0.41; P < 0.0001), the MSWS-12 scale (r2 = 0.46; P < 0.0001), time to walk 10 m (r2 = 0.51; P < 0.02) and walking speed (r2 =0.75; P < 0.001). Limitation of walking capacities was measurable up to 4550 m, strikingly above the 500-m limit of the EDSS. This objective odometer is a promising tool for evaluation and follow-up of patients with MS. Multiple Sclerosis 2007; 13: 220–223. http://msj.sagepub.com
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Affiliation(s)
- A Créange
- Service de Neurologie, Centre Hospitalier Universitaire Henri Mondor, AP-HP, Université Paris XII, Créteil, France.
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Morel Y, Malau M, Gordji A, Al Najjar Carpentier A, Levasseur M. Thrombose veineuse cérébrale profonde et rectocolite hémorragique. Rev Neurol (Paris) 2014. [DOI: 10.1016/j.neurol.2014.01.647] [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: 10/25/2022]
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10
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Sharma S, Chan E, Ishizawa M, Toom-Sauntry D, Gong SL, Li SM, Tarasick DW, Leaitch WR, Norman A, Quinn PK, Bates TS, Levasseur M, Barrie LA, Maenhaut W. Influence of transport and ocean ice extent on biogenic aerosol sulfur in the Arctic atmosphere. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd017074] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Sjostedt SJ, Leaitch WR, Levasseur M, Scarratt M, Michaud S, Motard-Côté J, Burkhart JH, Abbatt JPD. Evidence for the uptake of atmospheric acetone and methanol by the Arctic Ocean during late summer DMS-Emission plumes. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd017086] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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12
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Elliott S, Deal C, Humphries G, Hunke E, Jeffery N, Jin M, Levasseur M, Stefels J. Pan-Arctic simulation of coupled nutrient-sulfur cycling due to sea ice biology: Preliminary results. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jg001649] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Motard-Côté J, Levasseur M, Scarratt MG, Michaud S, Gratton Y, Rivkin RB, Keats K, Gosselin M, Tremblay JÉ, Kiene RP, Lovejoy C. Distribution and metabolism of dimethylsulfoniopropionate (DMSP) and phylogenetic affiliation of DMSP-assimilating bacteria in northern Baffin Bay/Lancaster Sound. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jc007330] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [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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14
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Luce M, Levasseur M, Scarratt MG, Michaud S, Royer SJ, Kiene R, Lovejoy C, Gosselin M, Poulin M, Gratton Y, Lizotte M. Distribution and microbial metabolism of dimethylsulfoniopropionate and dimethylsulfide during the 2007 Arctic ice minimum. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jc006914] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Boyd PW, Jickells T, Law CS, Blain S, Boyle EA, Buesseler KO, Coale KH, Cullen JJ, de Baar HJW, Follows M, Harvey M, Lancelot C, Levasseur M, Owens NPJ, Pollard R, Rivkin RB, Sarmiento J, Schoemann V, Smetacek V, Takeda S, Tsuda A, Turner S, Watson AJ. Mesoscale Iron Enrichment Experiments 1993-2005: Synthesis and Future Directions. Science 2007; 315:612-7. [PMID: 17272712 DOI: 10.1126/science.1131669] [Citation(s) in RCA: 355] [Impact Index Per Article: 20.9] [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: 11/02/2022]
Abstract
Since the mid-1980s, our understanding of nutrient limitation of oceanic primary production has radically changed. Mesoscale iron addition experiments (FeAXs) have unequivocally shown that iron supply limits production in one-third of the world ocean, where surface macronutrient concentrations are perennially high. The findings of these 12 FeAXs also reveal that iron supply exerts controls on the dynamics of plankton blooms, which in turn affect the biogeochemical cycles of carbon, nitrogen, silicon, and sulfur and ultimately influence the Earth climate system. However, extrapolation of the key results of FeAXs to regional and seasonal scales in some cases is limited because of differing modes of iron supply in FeAXs and in the modern and paleo-oceans. New research directions include quantification of the coupling of oceanic iron and carbon biogeochemistry.
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Affiliation(s)
- P W Boyd
- National Institute for Water and Atmospheric Research (NIWA) Centre for Chemical and Physical Oceanography, Department of Chemistry, University of Otago, Dunedin, New Zealand.
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Abstract
INTRODUCTION CADASIL is a hereditary cerebral arteriopathy leading to progressive disability and dementia usually observed at 60 years. OBSERVATION We report four patients aged>60 years with typical Notch3 mutations leading to CADASIL who did not have dementia or disability. Three of them presented with only transient neurological manifestations. MRI results showed extensive hyperintense signals in the white-matter on T2-weighted images contrasting with very few lacunar infarcts. CONCLUSION These observations suggest that silent or symptomatic infarcts, which were rare in the present cases may be responsible for the clinical severity in this disorder.
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Affiliation(s)
- A Mourad
- Service de Neurologie CHG, Place du Général Leclerc, Orsay
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17
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Buffin-Bélanger T, Roy AG, Levasseur M. Interactions entre les structures d'échappement et les structures à grande échelle dans l'écoulement turbulent des rivières à lit de graviers. ACTA ACUST UNITED AC 2005. [DOI: 10.7202/705425ar] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dans les rivières graveleuses, il est établi que les structures d'échappement formées dans la zone de recirculation à l'aval d'amas de galets génèrent d'intenses échanges turbulents. Le mécanisme responsable de l'échappement demeure par contre mal connu. Peu d'études sur la dynamique des structures d'échappement ont été réalisées dans des écoulements où le nombre de Reynolds est élevé comme c'est le cas en rivières. De plus, les connaissances actuelles ne tiennent pas compte des découvertes récentes sur la turbulence en rivière à lit de graviers où on a observé des structures de forte et de faible vitesse occupant toute la profondeur de l'écoulement et pouvant durer plusieurs secondes. Ces structures à grande échelle devraient jouer un rôle sur le mécanisme d'échappement étant donné l'influence de la vitesse ambiante sur la dynamique de la zone de recirculation. Nous rapportons les résultats de deux expériences originales sur les liens dynamiques entre les structures à grande échelle et le mécanisme d'échappement en aval d'un amas de galets. La première expérience repose sur l'analyse de corrélations croisées entre des séries de vitesses obtenues au sommet et à l'aval proximal d'un amas de galets. Les résultats montrent que les fortes fluctuations dans le sens de l'écoulement au sommet de l'obstacle sont liées, quelques instants plus tard, à de fortes fluctuations vers l'amont dans la zone de recirculation. La seconde expérience utilise la visualisation des structures d'échappement et la mesure simultanée des vitesses de l'écoulement. L'analyse combinée des images vidéo et de séries de vitesse suggère une relation entre le passage des structures à grande échelle et les manifestations de l'échappement. Ces résultats nous permettent de présenter un modèle où, lors du passage d'un front de haute vitesse, une structure d'échappement se développe et prend de l'expansion vers le lit et vers la surface en se propageant vers l'aval alors que, lors du passage d'un front de faible vitesse, elle s'élève vers la surface de manière plus cohérente. Cette étude propose un nouveau mécanisme d'échappement et révèle le rôle que joue la structure de l'écoulement ambiant sur le développement de structures dans les cours d'eau à lit graveleux.
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Jones KT, Levasseur M, Chang H, Madgwick S. 290. Calmodulin-dependent protein kinase II, and not protein kinase C, transduces the Ca2+ signal at fertilization. Reprod Fertil Dev 2005. [DOI: 10.1071/srb05abs290] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Mouse eggs arrest at metaphase II following ovulation and are only triggered to complete meiosis when fertilized. Sperm break the cell cycle arrest by a long-lasting series of Ca2+ spikes that lead to an activation of the anaphase-promoting complex. The signal transduction pathway is not fully resolved but both protein kinase C (PKC) and calmodulin-dependent protein kinase II (CamKII) activities increase at fertilization and previous pharmacological studies have implicated both in cell cycle resumption. Here we used a combination of pharmacological inhibitors and constitutively-active cRNA constructs of PKCα and CamKII microinjected into mouse eggs, to show that it is CamKII and not PKC that is the sufficient trigger for cell cycle resumption from metaphase II arrest.
Constitutively active PKC constructs had no effect on meiotic resumption but caused an immediate and persistent elevation in intracellular Ca2+ when store-operated Ca2+ entry was stimulated. With respect to meiotic resumption, the effects of constitutively-active CamKII on eggs were the same as sperm. Eggs underwent second polar body extrusion and pronucleus formation with normal timings; while both securin and cyclin B1 destruction, visualised by coupling to fluorescent protein tags, were complete by the time of polar body extrusion. Induction of a spindle checkpoint by overexpression of Mad2 or by spindle poisons blocked CamKII-induced meiotic resumption but the Ca2+ chelator BAPTA did not. Furthermore direct measurement of Ca2+ levels showed that CamKII did not induce exit from metaphase II arrest by raising Ca2+. Therefore we conclude that PKCs may play an important role in maintaining Ca2+ spiking at fertilization by promoting store-operated Ca2+ entry, while CamKII transduces cell cycle resumption, and lies downstream of sperm-induced Ca2+ release but upstream of a spindle checkpoint. These data, combined with the knowledge that CamKII activity increase at fertilization, suggest that mouse eggs undergo cell cycle resumption through stimulation of CamKII.
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Callahan S, Rousseau A, Knotter A, Bru V, Danel M, Cueto C, Levasseur M, Cuvelliez F, Pignol L, O'Halloran MS, Chabrol H. [Diagnosing eating disorders: presentation of a new diagnostic test and an initial epidemiological study of eating disorders in adolescents]. Encephale 2003; 29:239-47. [PMID: 12876548] [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: 03/03/2023]
Abstract
Precise diagnosis of eating disorders has long been problematic. First off, although the DSM IV provides clear criteria, these are applicable to a very narrow range of disorders. Subclinical disorders, although well defined in the literature, are difficult to diagnose as no tool has been previously available. These subclinical disorders are particularly important if one considers that they are often precursors to more serious and life-threatening eating disorders. In addition, choice of diagnostic tool for eating disorders has also long been the cause of difficulty for both researchers and clinicians. Although interviews are favored for their in-depth approach, they are sometimes difficult to implement and often too long and costly to use on a regular basis. Most available questionnaires are limited by their approach to one or two diagnostic categories, and again, until now, no tool has fully addressed the issue of subclinical disorders. The goal of this work was to translate and use a new questionnaire, The Questionnaire for Eating Disorders (Q-EDD), which was developed in the United States and based on both DSM IV criteria as well as carefully developed subclinical disorder criteria. The Q-EDD can identify the major eating disorder categories while at the same time distinguishing between different qualities in each (for example restricting versus compensatory anorexia). Moreover, the Q-EDD can identify several subclinical disorder categories, providing useful insight into potentially dangerous evolution of these disorders. In collaboration with one of the original authors, the questionnaire was translated into French with careful attention to DSM IV criteria in order to preserve its original validity. The questionnaire was read by several professionals in psychology as well as lay people to assure its face validity and ease of use. Once the questionnaire was adequately translated and corrected, it was used for an epidemiological study with a large sample of adolescents and young adults (n=1 001) from several Junior High and High Schools in the greater metropolitan area of Toulouse, France. The schools were located in a variety of neighborhoods and represented a wide range of population, some of them being more academic oriented, others being more oriented towards practical training. The population was composed of 703 females and 298 males, with an average age of 17.06 years. In addition, the population included several different ethnic categories, all of which are similarly represented in the general French population. The results from the Q-EDD showed levels of various clinical disorders to replicate data from previous epidemiological studies with 1.5% of the population suffering from a serious clinical DSM IV disorder; 7.9% suffering from DSM IV disorders NOS; and 20.9% suffering subclinical disorders. In addition to this finding of 30% of the population with an eating disorder, it was noted that a large number of these young people fell into the severe underweight and low weight categories. Indeed, nearly 10% of this group were within the weight criteria for anorexia, despite the fact that they did not meet the other criteria. This finding seemed to warrant additional investigation, and as a result, a different cut-off for severe underweight was established using literature references; this cut-off was set at the 10(th) percentile for BMI based on age. Yet, even with this new cut-off, 6% of this population still met a severe underweight criteria suggestive of anorexic pathology. These results led to the formulation of 2 hypotheses to explain this finding, the first of which examines morphological differences, the second of which suggests cultural differences in terms of eating habits and diet. The French version of the Q-EDD appears to follow the psychometric properties of the original version, moreover it provides useful and rich data regarding eating disorders in a format that is simple and efficient.
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Affiliation(s)
- S Callahan
- Centre d'Etudes et de Recherches en Psychopathologie, Université de Toulouse II, Le Mirail, 31058 Toulouse, France
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Michaud S, Levasseur M, Doucette G, Cantin G. Particle size fractionation of paralytic shellfish toxins (PSTs): seasonal distribution and bacterial production in the St Lawrence estuary, Canada. Toxicon 2002; 40:1451-62. [PMID: 12368115 DOI: 10.1016/s0041-0101(02)00163-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [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: 10/27/2022]
Abstract
We determined the seasonal distribution of paralytic shellfish toxins (PSTs) and PST producing bacteria in > 15, 5-15, and 0.22-5 microm size fractions in the St Lawrence. We also measured PSTs in a local population of Mytilus edulis. PST concentrations were determined in each size fraction and in laboratory incubations of sub-samples by high performance liquid chromatography (HPLC), including the rigorous elimination of suspected toxin 'imposter' peaks. Mussel toxin levels were determined by mouse bioassay and HPLC. PSTs were detected in all size fractions during the summer sampling season, with 47% of the water column toxin levels associated with particles smaller than Alexandrium tamarense (< 15 microm). Even in the > 15 microm size fraction, we estimated that as much as 92% of PSTs could be associated with particles other than A. tamarense. Our results stress the importance of taking into account the potential presence of PSTs in size fractions other than that containing the known algal producer when attempting to model shellfish intoxication, especially during years of low cell abundance. Finally, our HPLC results confirmed the presence of bacteria capable of autonomous PST production in the St Lawrence as well as demonstrating their regular presence and apparent diversity in the plankton.
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Affiliation(s)
- S Michaud
- Department of Fisheries and Oceans, Maurice Lamontagne Institute, 850 Route de la mer, Mont-Joli, Que, Canada G5H 3Z4.
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Woimant F, Hommel M, Adnet Bonte C, Baldauf E, Chedru F, Cohen A, de Broucker T, Devailly JP, Duclos H, Gaston A, Grobuis S, Kassiotis P, Levasseur M, Merland JJ, Mounier Vehier F, Nibbio A, Orgogozo JM, Outin H, Pinel F, Pruvo JP, Rancurel G, Saudeau D, Scart-Gres C, Sévène M, Touboul PJ, Vassel P, Zuber M, Arquizan C, Baron JC, Becker F, Bes A, Boulliat J, Bousser MG, Bracard S, Branchereau A, Castel JP, Caussanel JP, Civit J, Collard M, Davoine P, Deroudille L, Dumas R, Frerebeau P, Giroud M, Goldstein P, Lagarrigue J, Lejeune JP, Lestavel P, Leys D, Mahagne MH, Manelfe C, Mas JL, Masson M, Michel D, Moulin T, Perret J, Petit H, Proust B, Rouanet F, Rougemont D, Roux FX, Samson Y, Trouillas P. [Recommendations for the creation of neuro-vascular units]. Rev Neurol (Paris) 2001; 157:1447-56; discussion 1457-8. [PMID: 11924017] [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: 02/24/2023]
Affiliation(s)
- F Woimant
- Service de Neurologie, Hôpital Lariboisière, 2, rue Ambroise Paré, 75475 Paris
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Choinière R, Levasseur M, Robitaille N. [Not Available]. Rech Amerindien Que 2001; 18:29-37. [PMID: 11635615] [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: 02/22/2023]
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Bouchard C, Levasseur M. [Kleine-Levin syndrome]. Rev Neurol (Paris) 2001; 157:344-5. [PMID: 11319500] [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: 02/19/2023]
Affiliation(s)
- C Bouchard
- Service de médecine-neurologie, Centre Hospitalier d'Orsay, Orsay, France
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Pappata S, Levasseur M, Gunn RN, Myers R, Crouzel C, Syrota A, Jones T, Kreutzberg GW, Banati RB. Thalamic microglial activation in ischemic stroke detected in vivo by PET and [11C]PK1195. Neurology 2000; 55:1052-4. [PMID: 11061271 DOI: 10.1212/wnl.55.7.1052] [Citation(s) in RCA: 189] [Impact Index Per Article: 7.9] [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: 11/15/2022] Open
Abstract
Using quantitative PET, the authors studied the binding of [11C]PK11195, a marker of activated microglia, in the thalamus of patients with chronic middle cerebral artery infarcts. All patients showed increased [11C]PK11195 binding in the ipsilateral thalamus, indicating the activation of microglia in degenerating projection areas remote from the primary lesion. A persistent increase in [11C]PK11195 binding suggests active, long-term thalamic microstructural changes after corticothalamic connection damage.
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Affiliation(s)
- S Pappata
- INSERM U334, Service Hospitalier Frédéric Joliot, Orsay, France.
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McDougall A, Levasseur M, O'Sullivan AJ, Jones KT. Cell cycle-dependent repetitive Ca(2+)waves induced by a cytosolic sperm extract in mature ascidian eggs mimic those observed at fertilization. J Cell Sci 2000; 113 Pt 19:3453-62. [PMID: 10984436 DOI: 10.1242/jcs.113.19.3453] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sperm-triggered Ca(2+) oscillations occur throughout the animal kingdom. The mechanism sperm use to trigger Ca(2+) oscillations at fertilization has not been resolved in any egg. The temporal, spatial and regulatory characteristics of the Ca(2+) oscillations during fertilization in ascidians offer a unique advantage over other systems for determining the mechanism of fertilization. For example, sperm trigger two phases of Ca(2+) oscillations that are all waves in ascidians. The first of these Ca(2+) waves begins at the point of sperm-egg fusion while a second phase of Ca(2+) waves originates at a vegetal protrusion termed the contraction pole. In addition, cyclin B1-dependent kinase activity provides a form of positive feedback, maintaining the second phase of Ca(2+) waves during meiosis and thereby ensuring meiotic exit. We therefore prepared cytosolic ascidian sperm extracts or MonoQ-fractionated ascidian sperm extracts from this urochordate to investigate if a Ca(2+)-releasing sperm-borne factor was responsible for egg activation. Spatially, ascidian sperm extract induced repetitive Ca(2+) waves that mimicked the spatial pattern displayed during fertilization: all the second-phase Ca(2+) waves originated at a vegetal protrusion termed the contraction pole (thus mimicking fertilisation). We also demonstrated that ascidian sperm extract-induced Ca(2+) oscillations were maintained when CDK activity was elevated and MAP kinase activity was low, as found previously for sperm-triggered Ca(2+) oscillations. As would be predicted, large doses of ascidian sperm extract injected into prophase-stage oocytes, lacking CDK activity, failed to induce any Ca(2+) release even though they responded to microinjection of the Ca(2+)-releasing second messenger inositol 1,4,5-trisphosphate. Finally, since the Ca(2+)-releasing activity from Mono-Q fractionated ascidian sperm extract eluted predominantly as one fraction, this may imply that one factor is responsible for the Ca(2+)-releasing activity. These data support a model of egg activation whereby the sperm introduces a Ca(2+)-releasing cytosolic factor into the egg. We demonstrated that ascidian sperm contain a protein factor(s) that is regulated by the egg CDK activity and can trigger all the Ca(2+)waves observed at fertilization with a spatial pattern that mimics those initiated by sperm.
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Affiliation(s)
- A McDougall
- Department of Physiological Sciences, The Medical School, University of Newcastle upon Tyne, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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Monfort P, Demers S, Levasseur M. Bacterial dynamics in first year sea ice and underlying seawater of Saroma-ko Lagoon (Sea of Okhotsk, Japan) and resolute passage (High Canadian Arctic): inhibitory effects of ice algae on bacterial dynamics. Can J Microbiol 2000; 46:623-32. [PMID: 10932356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The seasonal development of bacterial abundance in first year bottom ice and underlying seawater were studied at Saroma-ko Lagoon in Hokkaido, Japan, and at Resolute Passage in the High Canadian Arctic during the algal bloom in spring 1992. The aim of this study was to evaluate whether the high algal concentrations reached during the bloom of ice algae have inhibitory effects on bacterial dynamics. Bacterial abundance (measured as total cell count and colony-forming units CFU) increased with the increase of the algal biomass up to 500 micrograms Chla.L-1 in both locations. Culturable fraction (measured as the percentage of CFU counts versus the total cell counts) was between 7% and 22% at Saroma-ko, and approximately 0.08% at Resolute Passage. When algal biomass exceeded 500 micrograms of Chla.L-1, both bacterial abundance and culturable fraction decreased significantly. There was a maximum threshold of algal biomass (between 500 and 800 micrograms of Chla.L-1) after which bacterial dynamics become negatively coupled to the algal biomass. These results suggest that bactericidal and/or bacteriostatic compounds from these extremely high algal concentrations could explain the decrease in bacterial abundance and culturability in bottom ice observed after the ice algae bloom.
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Affiliation(s)
- P Monfort
- Unité Mixte de Recherche n. 5556 "Ecosystèmes Lagunaires" CNRS-Université Montpellier II, France.
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Klosowski S, Morisot C, Truffert P, Levasseur M, Thelliez P, Dubos JP, Djebara A, Boucly B, Deroubaix P, Lequien P. [Non-medical factors in perinatal health. A study of socioeconomic anc cultural features of women admitted to the maternity hospital in Lens (Pas-de-Calais)]. Arch Pediatr 2000; 7:349-56. [PMID: 10793921 DOI: 10.1016/s0929-693x(00)88829-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND The aim of this study was to determine the influence of medical and non-medical factors on perinatal health in an underpriviledged area, the ex-coal mines of Lens (Pas-de-Calais). POPULATION AND METHODS This prospective study concerned 1,000 women who delivered in the maternity hospital of Lens between January 5, 1993 and May 13, 1993. The relationships between preterm delivery, low birth weight and maternal socioeconomic and cultural characteristics were analyzed. RESULTS The women included presented adverse pregnancy outcomes. Preterm delivery, low birth weight and neonatal transfer rates were respectively 6.9%, 7.3% and 12.7% higher than the average regional rates. In contrast with these results, antenatal care could be considered correct or even better. The poor socioeconomic status of the population appeared to be a very significant perinatal risk factor. CONCLUSION At present, in an unfavourable regional conjuncture, socioeconomic and cultural factors have adverse effects on perinatal morbidity and mortality independent of medical factors like prenatal care. The prevention of poor perinatal outcome should be based on these data. Not the access to the health care system but the manner of dispensing health care should require great consideration.
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Affiliation(s)
- S Klosowski
- Service de médecine néonatale, Centre hospitalier Docteur-Schaffner, Lens, France
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Middleton PG, Norden J, Levett D, Levasseur M, Miller S, Irving JA, Wood A, Reid MM, Taylor PR, Proctor SJ. Population-based study of the pattern of molecular markers of minimal residual disease in childhood and adult acute lymphoblastic leukemia: an assessment of the practical difficulty of representative sampling for trial purposes. Northern Region Haematology Group. Med Pediatr Oncol 2000; 34:106-10. [PMID: 10657870 DOI: 10.1002/(sici)1096-911x(200002)34:2<106::aid-mpo6>3.0.co;2-l] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND The prevalence, in unselected patients with acute lymphoblastic leukaemia (ALL), of clonal rearrangements suitable for minimal residual disease (MRD) studies has not been formally investigated. PROCEDURE This was a prospective, demographic study of the frequency of molecular markers of MRD in all patients with ALL presenting over 5 years within the Northern Health Region of England (population 3.1 million). Presentation marrow samples were examined to detect informative markers. RESULTS One hundred twenty-four children (age <15 years) developed non-Burkitt ALL. No material was available for study in 21. Eighty-six had clonal gene rearrangements (BCR/ABL, immunoglobulin heavy chain (IGH) and/or T cell receptor (TCR) gene rearrangements). All entered remission; 84 (68% of the original cohort) survived to become eligible for MRD studies. One hundred sixteen adults developed ALL, of whom 48 were not studied due to insufficient cellular material in the bone marrow aspirate or to logistical problems in central referral of samples from other hospitals. Material from elderly adults (age >55 years) was less likely to be sent for analysis, 36% vs. 59% (P = 0.024). Thirty-eight had BCR/ABL and/or IGH/TCR gene rearrangements. Thirty-one (27% of the original cohort) entered remission and became eligible for MRD studies. Informative gene rearrangements were more common in children than adults (83% vs. 63%, P < 0.003). CONCLUSIONS The results reveal substantial potential, unintentional, selection bias. Large-scale multicentre studies of MRD in children may well produce clinically relevant and representative data. Those who mount similar studies in adults should not assume they will be similarly representative or as successful in accrual of material.
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Affiliation(s)
- P G Middleton
- Leukaemia Research Fund Remission Unit, Newcastle upon Tyne, UK
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Levasseur M, McDougall A. Sperm-induced calcium oscillations at fertilisation in ascidians are controlled by cyclin B1-dependent kinase activity. Development 2000; 127:631-41. [PMID: 10631183 DOI: 10.1242/dev.127.3.631] [Citation(s) in RCA: 52] [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] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The generation of calcium oscillations at fertilisation and during mitosis appears to be controlled by the cell cycle machinery. For example, the calcium oscillations in oocytes and embryos occur during metaphase and terminate upon entry into interphase. Here we report the manipulation of sperm-triggered calcium oscillations by cyclin-dependent kinase (CDK) activity, the major component of maturation/M phase promoting factor (MPF). To control the CDK activity we microinjected mRNAs encoding full-length GFP-tagged cyclin B1 or a truncated and therefore stabilised form of cyclin B1 ((delta)90) into unfertilised oocytes. In the presence of full-length cyclin B1, the calcium oscillations terminate when cyclin B1 levels fall along with the concomitant fall in the associated CDK activity. In addition, when the CDK activity is elevated indefinitely with (delta)90 cyclin B1, the calcium oscillations also continue indefinitely. Finally, in oocytes that contain low mitogen-activated protein (MAP) kinase activity and elevated CDK activity, the sperm-triggered calcium oscillations are again prolonged. We conclude that the CDK activity of the ascidian oocyte can be regarded as a positive regulator of sperm-triggered calcium oscillations, a finding that may apply to other oocytes that display sperm-triggered calcium oscillations at fertilisation. Furthermore, these findings may have a bearing upon the mitotic calcium signals of early embryos.
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Affiliation(s)
- M Levasseur
- Department of Physiological Sciences, The Medical School, University of Newcastle upon Tyne, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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Sharma S, Barrie LA, Plummer D, McConnell JC, Brickell PC, Levasseur M, Gosselin M, Bates TS. Flux estimation of oceanic dimethyl sulfide around North America. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1999jd900207] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Herbert M, Morgan J, Levasseur M, Murdoch A, McDougall A. O-245. A non-degradable form of cyclin can be used to induce arrest at the first meiotic metaphase in human oocytes. Hum Reprod 1999. [DOI: 10.1093/humrep/14.suppl_3.135-a] [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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McDougall A, Levasseur M. Sperm-triggered calcium oscillations during meiosis in ascidian oocytes first pause, restart, then stop: correlations with cell cycle kinase activity. Development 1998; 125:4451-9. [PMID: 9778504 DOI: 10.1242/dev.125.22.4451] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have investigated the relationship between the sperm-triggered Ca2+ oscillations and the activities of two cell cycle kinases (MPF activity and MAP kinase activity) at fertilisation of Ascidiella aspersa oocytes. Maturation Promoting Factor (MPF) activity is elevated in the metaphase I (MI)-arrested unfertilised oocyte (as measured by phosphorylation of exogenous histone H1) and falls 5 minutes after fertilisation to remain at low levels for 5 minutes. The first polar body (pb1) is extruded when the MPF activity is low. The MPF activity is elevated again 15 minutes after fertilisation and finally becomes inactivated 25 minutes after fertilisation when the pb2 is extruded. MAP kinase activity increases from an initially elevated level to reach maximal activity 10 minutes after fertilisation and subsequently falls to reach low levels 25 minutes after fertilisation. Sperm trigger a series of Ca2+ oscillations that pause for 5 minutes while only the MPF activity is low and are present when both MPF and MAP kinase activity are elevated. We next attempted to determine whether the second phase of calcium oscillations is required to reactivate the MPF activity that precedes extrusion of the second polar body. To do this, we triggered a monotonic Ca2+ signal. This leads to the inactivation of MPF followed by MPF reactivation. The MPF activity then remains elevated for an extended period of time. During this period, the chromatin remains condensed and a metaphase II (MII) spindle forms. Fertilisation of these MII oocytes triggers extrusion of pb2 in 7 minutes. Interestingly, the second phase of Ca2+ oscillations is completely absent when MII oocytes are fertilised. Thus, in both MI and MII oocytes, the sperm-triggered Ca2+ oscillations follow the MPF activity. Finally we discuss our finding that the Ca2+ release system remains sensitive during the metaphase-like state (including the period when the Ca2+ oscillations pause).
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Affiliation(s)
- A McDougall
- Department of Physiological Sciences, The Medical School, University of Newcastle, Framlington Place, Newcastle upon Tyne NE2 4HH, UK. a.
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Dubois C, Dufour P, Quandalle F, Lanvin D, Levasseur M, Monnier JC. [Breech presentation: management (304 cases)]. Contracept Fertil Sex 1998; 26:363-71. [PMID: 9648380] [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
UNLABELLED BUT: Try to precise the optimal management in 1997 face a breech presentation. METHOD Between January 1991 and December 1995, 304 cases of breech presentations were listed at the maternity of Pavillon Victor Olivier (Lille). From these 304 breech presentations, all parities blended, the authors have analysed the mode of delivery of these patients, distinguishing the para one from the multiparous women and the preterm babies from the other babies. From this study and a review of the literature, were discussed the criterions which can help the practitioner to determine the mode of delivery of these fetus. RESULTS The results show a cesarean section (cs) rate of 51% (41% of first intention cs and 10% of second intention cs were realized only for primiparity + breech presentation and 67% of the para one women benefited from a first intention cs 8.72% of vaginal deliveries were complicated, and 5 fetal injuries were noted without sequel. On 296 live new-borns, only 2 cases of fetal death were perhaps due to the vaginal delivery. Fetal mortality is principally reliable at the prematurity and the congenital malformations, but finally, not due to mode of delivery. CONCLUSION The difficulty is to determine rigorous criterions of selection to authorize a vaginal delivery without spoil the fetal pronostic. The major criterions are a perfect radiopelvimetry, an estimated fetal weight < 3800 g for the para one women and < 4300 g for the multiparous woman, a well flexed fetal head, favorable obstetric conditions ond the absence of maternal or fetal complications. The primiparity is not an indication of systematic cesariean section.
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Affiliation(s)
- C Dubois
- Hôpital Jeanne de Flandre, CHRU de Lille
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Michel C, Legendre L, Ingram RG, Gosselin M, Levasseur M. Carbon budget of sea-ice algae in spring: Evidence of a significant transfer to zooplankton grazers. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96jc00045] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.7] [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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Ducros A, Nagy T, Alamowitch S, Nibbio A, Joutel A, Vahedi K, Chabriat H, Iba-Zizen MT, Julien J, Davous P, Goas JY, Lyon-Caen O, Dubois B, Ducrocq X, Salsa F, Ragno M, Burkhard P, Bassetti C, Hutchinson M, Vérin M, Viader F, Chapon F, Levasseur M, Mas JL, Delrieu O. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, genetic homogeneity, and mapping of the locus within a 2-cM interval. Am J Hum Genet 1996; 58:171-81. [PMID: 8554054 PMCID: PMC1914956] [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: 01/31/2023] Open
Abstract
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a recently identified autosomal dominant cerebral arteriopathy characterized by the recurrence of subcortical infarcts leading to dementia. A genetic linkage analysis conducted in two large families recently allowed us to map the affected gene on chromosome 19 in a 12-cM interval bracketed by D19S221 and D19S215. In the present study, these first 2 families and 13 additional ones, including a total of 199 potentially informative meiosis, have been genotyped with eight polymorphic markers located between D19S221 and D19S215. All families were linked to chromosome 19. The highest combined lod score (Zmax = 37.24 at theta = .01) was obtained with marker D19S841, a new CAn microsatellite marker that we isolated from chromosome 19 cosmids. The recombinant events observed within these families were used to refine the genetic mapping of CADASIL within a 2-cM interval that is now bracketed by D19S226 and D19S199 on 19p13.1. These data strongly suggest the genetic homogeneity of this recently identified condition and establish the value of its clinical and neuroimaging diagnostic criteria. Besides their importance for the ongoing positional cloning of the CADASIL gene, these data help to refine the genetic mapping of CADASIL relative to familial hemiplegic migraine and hereditary paroxysmal cerebellar ataxia, conditions that we both mapped within the same chromosome 19 region.
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Affiliation(s)
- A Ducros
- INSERM U25, Faculté de Médecine Necker, Paris, France
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Levasseur M, Middleton PG, Angus B, Proctor SJ, Norden J, Howard MR. c-MYC gene abnormalities in high grade and centroblastic-centrocytic non-Hodgkins lymphoma. Leuk Lymphoma 1995; 18:131-6. [PMID: 8580815 DOI: 10.3109/10428199509064933] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Fifty nine cases of high grade and centroblastic-centrocytic (cc) Non Hodgkins Lymphoma (NHL) were investigated for mutations and gross gene rearrangements in the 5' region of the c-MYC gene. Mutations in this region, and the presence of hypermutated c-MYC genes, have been associated with poor prognostic groups. All cases showed normal c-MYC gene organisation on Southern blot analysis indicating absence of gross gene rearrangements. PCR amplification and restriction digest analysis of the exon 1/intron 1 region revealed point mutations in 7 cases. No evidence for hypermutation was found. Mutations were relatively more common in high grade NHL (6/39) than in cc-NHL (1/20). There was no correlation with disease status at presentation or relapse or the presence of extranodal disease. The cc-NHL case with a c-MYC mutation subsequently transformed to high grade disease. These data suggest that hypermutation of the c-MYC gene is a relatively rare event in cc-NHL and high grade NHL and does not contribute to the aetiology in the majority of cases. Mutation of c-MYC in cc-NHL may predict transformation to high grade disease.
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Affiliation(s)
- M Levasseur
- Leukaemia Research Fund Laboratory, Medical School, Newcastle upon Tyne, UK
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37
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Chabriat H, Sachon C, Levasseur M, Grimaldi A, Pappata S, Rougemont D, Masure MC, De Recondo A, Samson Y. Brain metabolism after recurrent insulin induced hypoglycaemic episodes: a PET study. J Neurol Neurosurg Psychiatry 1994; 57:1360-5. [PMID: 7964812 PMCID: PMC1073187 DOI: 10.1136/jnnp.57.11.1360] [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: 01/28/2023]
Abstract
Neuropsychological testing was carried out and the rate of oxygen metabolism in the brain was measured by PET in 15 highly selected patients with type 1 diabetes. The aim was to investigate the impact on the brain of hypoglycaemic comas resulting from insulin treatment. No significant difference was found between nine patients with a history of more than 10 hypoglycaemic comas and six others who denied any history of such events. These data suggest that intensified insulin treatment, although increasing the frequency of hypoglycaemic coma, may not always be harmful for the brain. This may be explained by the limited duration of hypoglycaemic coma induced by conventional insulin treatment.
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Affiliation(s)
- H Chabriat
- Service Hospitalier Frédéric Joliot, Dripp, CEA, Orsay, France
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38
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Levasseur M, Maung ZT, Jackson GH, Kernahan J, Proctor SJ, Middleton PG. Relapse of acute lymphoblastic leukaemia 14 years after presentation: use of molecular techniques to confirm true re-emergence. Br J Haematol 1994; 87:437-8. [PMID: 7947297 DOI: 10.1111/j.1365-2141.1994.tb04942.x] [Citation(s) in RCA: 15] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Late relapse after successful treatment of acute lymphoblastic leukaemia (ALL) in children is well-recognized but rare. It is often uncertain whether this represents a true relapse of the original disease or a second malignancy. We present the case of a patient who relapsed 14 years after the original diagnosis of childhood ALL in whom both the original leukaemic cells and those taken at relapse had an identical T cell receptor gamma (TCRG) gene rearrangement. This analysis confirms that this relapse is a true re-emergence of the patient's original disease. The term 'cure' should be used with caution in childhood ALL, even after long periods in continuous remission.
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Affiliation(s)
- M Levasseur
- Leukaemia Research Fund Laboratory, Medical School, University of Newcastle upon Tyne
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39
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Pappata S, Chabriat H, Levasseur M, Legault-Demare F, Baron JC. Marchiafava-Bignami disease with dementia: severe cerebral metabolic depression revealed by PET. J Neural Transm Park Dis Dement Sect 1994; 8:131-7. [PMID: 7893375 DOI: 10.1007/bf02250924] [Citation(s) in RCA: 12] [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] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The Cerebral Metabolic Rate of Glucose (CMRGlu) was measured with positron emission tomography and 18F-FDG in a patient with Marchiafava-Bignami Disease (MBD)-related dementia. Despite MRI evidence of lesions essentially limited to the corpus callosum (CC), but consistent with the cognitive pattern of cortical dementia, the CMRGlu was markedly reduced in the frontal and temporo-parieto-occipital association cortices. Disruption of cortico-cortical networks crossing the CC presumably contributed to, but may not in and by itself explain, the severity of the clinical-metabolic findings in this patient. An additional role could be played by microscopic white matter lesions and/or neocortical neuronal loss, which have been occasionally observed in post-mortem studies of MBD patients.
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Affiliation(s)
- S Pappata
- Service Hospitalier Frédéric Joliot (SHFJ), CEA, DRIPP, Orsay, France
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40
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Stephenson PA, Bakoula C, Hemminki E, Knudsen L, Levasseur M, Schenker J, Stembera Z, Tiba J, Verbrugge HP, Zupan J. Patterns of use of obstetrical interventions in 12 countries. Paediatr Perinat Epidemiol 1993; 7:45-54. [PMID: 8426831 DOI: 10.1111/j.1365-3016.1993.tb00600.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [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: 01/30/2023]
Abstract
Recent obstetrical practice trends in 12 countries were surveyed. There was a 3-fold difference in caesarean section rates and a 10-fold difference in instrumental vaginal delivery rates among countries. There was a net increase in the caesarean section rate of all countries over the study period and a net decrease in the instrumental vaginal delivery rate of some countries. There was a decrease in the caesarean section rate during the last year of observation in Australia, Denmark and Finland. In general, countries with high caesarean rates also had high instrumental vaginal delivery rates. There was no consistent relationship between use of caesarean section and use of instrumental vaginal delivery, although in several countries increasing use of caesarean section was accompanied by decreasing use of instrumental vaginal delivery. Oxytocin use rates were associated positively with instrumental delivery but not with caesarean section rates. While it was not possible to determine the proportions of women who received appropriate obstetrical care, we can infer that a significant proportion of interventions were unnecessary or only marginally beneficial. Continued increases in rates of obstetrical intervention are unlikely to result in improvements in birth outcome overall and may pose a risk to mothers and their newborns.
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Affiliation(s)
- P A Stephenson
- Centrum för Folkhälsoforskning, Landstinget i Värmland, Karlstad, Sweden
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42
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Baron JC, Levasseur M, Mazoyer B, Legault-Demare F, Mauguière F, Pappata S, Jedynak P, Derome P, Cambier J, Tran-Dinh S. Thalamocortical diaschisis: positron emission tomography in humans. J Neurol Neurosurg Psychiatry 1992; 55:935-42. [PMID: 1431957 PMCID: PMC1015196 DOI: 10.1136/jnnp.55.10.935] [Citation(s) in RCA: 118] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To investigate further the relations between cortical energy metabolism and neuropsychological impairment after unilateral thalamic lesion, 55 patients underwent positron emission tomography studies of either cortical oxygen consumption or glucose utilisation, including eight repeat studies, at times ranging from 4 days to 98 months after the onset of the lesion [stroke (n = 44) or stereotaxic VL-Vim thalamotomy performed for movement disorders (n = 11)]. Patients with thalamotomy were also studied preoperatively and the surgery induced a significant fall in cortical metabolism on both sides (more so ipsilaterally); post-operatively the magnitude of the ipsilateral cortex hypometabolism was positively correlated to the severity of global neuropsychological impairment; similar but less significant findings were obtained for the ipsilateral/contralateral cortical metabolic asymmetry. With respect to the whole patient sample, the cortical metabolic asymmetry was initially pronounced, with subsequent monoexponential recovery, in the cognitively impaired study group, but it was only mild and showed no meaningful trend for recovery in the cognitively unaffected study group; yet even soon (< 3 months) after thalamic lesion there was a noticeable overlap of individual asymmetry values among the two study groups. These results lend further support to the view that the neuropsychological impairment that frequently follows unilateral thalamic lesions is reflected in a depression of synaptic activity in both the overlying and the contralateral cerebral cortices. For individual patients, this study also illustrates the potentially misleading nature of the measured cortical metabolic asymmetry with respect to neuropsychological status, especially at late times after lesion, in part because side to side metabolic ratios do not reflect bilateral changes.
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Abstract
In 8 patients with small unilateral posterolateral thalamic (or, in one case, thalamocapsular) stroke (infarction or hemorrhage) selected on strict clinical (pure hemisomatosensory deficit without hemiparesis, visual field defect or neuropsychological impairment) and MRI criteria, we studied cortical energy metabolism using positron emission tomography with the 18F-fluorodeoxyglucose or the 15O-oxygen method. We found no significant ipsi- or contra-lateral metabolic depression either in the whole cortical mantle or in the sensorimotor cortex. These results support the hypothesis that location of thalamic stroke is a major determinant of the ipsilateral cortical hypometabolism characteristic of cognitively impaired patients with thalamic lesions and further emphasize the influence of the "non-specific" thalamocortical system on resting cortical metabolism. The lack of sensorimotor cortex hypometabolism in our patients suffering from hemidysesthesia and/or -hyperpathia also suggests that cortical metabolism is unaltered in thalamic pain.
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Affiliation(s)
- H Chabriat
- Biology Department, Service Hospitalier Frédéric Joliot, CEA, Caen, France
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44
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Chabriat H, Levasseur M, Vidailhet M, Loc'h C, Mazière B, Bourguignon MH, Bonnet AM, Zilbovicius M, Raynaud C, Agid Y. In-vivo SPECT imaging of D2 receptor with iodine-iodolisuride: results in supranuclear palsy. J Nucl Med 1992; 33:1481-5. [PMID: 1386104] [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: 12/26/2022] Open
Abstract
We assessed the potential use of [123I]iodolisuride (ILIS), a new iodine ergolene derivative, to study human striatal D2 dopamine receptors with SPECT. In normal subjects, we found that the tracer accumulated preferentially in striatum. This was prevented by high doses of haloperidol. The striatal accumulation was maximal between 60 and 180 min after injection. The striatum-to-cerebellum radioactivity concentration ratio as an index of specific binding, measured 60 min after injection, was 1.52 +/- 0.19 (mean +/- s.d.) in controls and 1.36 +/- 0.11 in patients with supranuclear palsy (p less than 0.03). Our results show that ILIS may be used to study D2 receptors with SPECT. In-vivo changes of D2 receptors in human brain may be detected with this method.
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Affiliation(s)
- H Chabriat
- Service Hospitalier Frédéric Joliot, C.E.A., DRIPP, Orsay, France
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45
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Levasseur M, Baron JC, Sette G, Legault-Demare F, Pappata S, Mauguière F, Benoit N, Tran Dinh S, Degos JD, Laplane D. Brain energy metabolism in bilateral paramedian thalamic infarcts. A positron emission tomography study. Brain 1992; 115 ( Pt 3):795-807. [PMID: 1628203 DOI: 10.1093/brain/115.3.795] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [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: 12/27/2022] Open
Abstract
Positron emission tomography (PET) studies of the cerebral metabolic rate of oxygen (CMRO2) were performed in seven consecutive patients with bilateral paramedian thalamic infarcts (BPTI), selected on neuroradiological and clinical criteria. The latter consisted of sudden onset of coma or confusion followed by a persistent amnesia of varying severity, with or without language impairment and frontal lobe signs. There was a highly significant decrease of CMRO2 for the whole cortex as well as for all the regions analysed: medial-frontal, latero-frontal, temporal, sensorimotor and posterior associative cortex. The mean regional metabolic ratios (region/whole cortex CMRO2) were not significantly different from controls, indicating an essentially uniform effect in the cortex, except the sensorimotor ratio which was significantly increased. Diffuse cortical hypometabolism most likely reflects thalamo-cortical deafferentation secondary to damage to the 'non-specific' thalamic nuclei, while sparing of the latero-ventral thalamus presumably explains the relative preservation of the sensorimotor cortex metabolism. Although no clear-cut individual relationship was found between magnitude of cortical hypometabolism and the severity and pattern of neuropsychological impairment, the data suggest that the former underlies and/or reflects the latter. Further studies with higher resolution PET devices might shed more light on the relationships between distinct cognitive patterns and specific topography of cortical hypometabolism in BPTI patients.
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Affiliation(s)
- M Levasseur
- Service Hospitalier Frédéric Joliot, Orsay, France
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Abstract
Analysis of the final phase of the overarm handball throw was carried out by a microcomputerized treatment of photographic images taken simultaneously in two grid layouts. Reflective stickers on the joints of the throwing arm (shoulder, elbow, wrist) allowed the coordinates of these three points to be measured against a reference on the wall. Using a mathematical treatment and Euler matrices, the movement could be studied in space. The results confirmed that humeral rotation occurs during the overarm handball throw. Initial external rotation was immediately followed with internal rotation about 40 ms before ball release.
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Affiliation(s)
- F Chagneau
- Laboratoire de Mécanique appliquée, I.U.T., Rennes, France
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Semah F, Levasseur M, Blétry O, Bousser MG. [Isolated trigeminal neuritis and primary Gougerot-Sjögren's syndrome]. Presse Med 1990; 19:871. [PMID: 2140188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Pappata S, Mazoyer B, Tran Dinh S, Cambon H, Levasseur M, Baron JC. Effects of capsular or thalamic stroke on metabolism in the cortex and cerebellum: a positron tomography study. Stroke 1990; 21:519-24. [PMID: 2326833 DOI: 10.1161/01.str.21.4.519] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.7] [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: 12/31/2022]
Abstract
We used positron emission tomography to study the cortical and cerebellar metabolic rates in 21 strictly selected patients with pure internal capsular infarct (n = 8), thalamocapsular hemorrhage (n = 6), or pure thalamic stroke (n = 7). Significant diffuse ipsilateral cortical hypometabolism relative to 62 controls free of cerebrovascular risk factors was frequently, although not consistently, found in the 13 patients with thalamocapsular or thalamic lesions and neuropsychological impairment but was absent from the eight patients with pure internal capsule infarct and free of neuropsychological deficit. These data suggest that damage to the thalamus or the thalamocortical projections is important in the development of ipsilateral cortical hypometabolism and that the latter may underlie the associated neuropsychological impairment. Significant contralateral cerebellar hypometabolism relative to 49 controls was found in three of six patients with pure internal capsule infarct, suggesting a pathogenetic role for the corticopontocerebellar system. However, the occurrence of hypometabolism in two of six patients with thalamic lesions indicates that this phenomenon may also result either from damage to the ascending cerebellothalamocortical system or indirectly from hypofunction of the cerebral cortex. No systematic association was observed between crossed cerebellar hypometabolism and ipsilateral ataxia.
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Affiliation(s)
- S Pappata
- Service Hospitalier Frédéric Joliot, Département de Biologie, Commissariat à l'Energie Atomique, Orsay, France
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Le Rumeur E, Le Moyec L, Chagneau F, Levasseur M, Toulouse P, Le Bars R, de Certaines J. Phosphocreatine and pH recovery without restoration of mechanical function during prolonged activity of rat gastrocnemius muscle: an in vivo 31P NMR study. Arch Int Physiol Biochim 1989; 97:381-8. [PMID: 2480094 DOI: 10.3109/13813458909104551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Metabolic impairment in skeletal muscle was suggested to be involved in the development of local mechanical fatigue but until now results have dealt with short activity periods whereas little data on exhaustive and prolonged exercises are available. Stimulations of rat leg muscle lasting 45 min were induced by tetanic trains delivered via sciatic nerve at five different rhythms. Energy metabolism of the stimulated gastrocnemius muscle was followed by 31P NMR spectroscopy using surface coil while mechanical function was recorded. Our data showed a decrease in the force level to very low values a few minutes after exercise onset. This mechanical impairment only induced a transient metabolic failure followed by rapid restoration of high phosphocreatine (PCr) values and intracellular pH, without mechanical recovery. In addition, at the end of exercise, the PCr content was proportional to the fatigue level. As these experiments could not have impaired neuromuscular junction, the data would indicate that fatigue was maintained by a mechanism which does not appear to depend directly on muscle cell energy stores.
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Affiliation(s)
- E Le Rumeur
- Laboratoire de Physiologie Médicale, Université de Rennes, France
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50
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Sette G, Baron JC, Mazoyer B, Levasseur M, Pappata S, Crouzel C. Local brain haemodynamics and oxygen metabolism in cerebrovascular disease. Positron emission tomography. Brain 1989; 112 ( Pt 4):931-51. [PMID: 2789086 DOI: 10.1093/brain/112.4.931] [Citation(s) in RCA: 163] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Using position emission tomography (PET) and equilibrium imaging with oxygen-15 labelled gases, the cerebral blood flow (CBF), blood volume (CBV), oxygen extraction fraction (OEF) and oxygen consumption rate (CMRO2) were measured in multiple regions of interest over the cerebral cortex of 5 control subjects, 4 patients with strictly unilateral longstanding carotid artery occlusion, 1 patient with middle cerebral artery embolic stroke in the acute stage, and 4 patients with subcortical stroke and no cervical arterial disease. In each control subject, the regional CBV was linearly and positively correlated with both CBF and CMRO2, while the local mean transit time (t = CBV/CBF) was uniformly distributed, reflecting the local adaptation of both the vascular tone and the capillary density to the metabolic demand at constant cerebral perfusion pressure that characterizes the normal brain. In patients with subcortical stroke, cortical blood volume was reduced in proportion to the matched reduction in CBF and CMRO2, suggesting that the metabolic depression resulting from cortical deafferentation increases the resting tone of pial vessels. Unilateral carotid occlusion induced larger CBV and t, and steeper slopes of the CBV-CBF relationship, particularly on the occluded but also on the patent side. The assessment of the local cerebral perfusion pressure (CPP) as judged by the ratio CBF/CBV in 3 patients with focally raised OEF and preserved or reduced CMRO2, allowed the demonstration in multiple cerebral regions of single patients of two well-known physiological phenomena: the autoregulation of CBF, followed by the rise of the OEF as local CPP falls further. In addition, the depression of CMRO2 in the ischaemic cortex was associated with a trend for CBV to return towards normal values, compared with the maximally elevated CBV found in oligaemic but metabolically normal areas. This suggests that a process of metabolic vasoconstriction may participate, among other factors, in the vascular collapse that occurs, and would serve to regenerate some haemodynamic reserve, at very low CPP levels.
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Affiliation(s)
- G Sette
- Service Hospitalier Frédéric Joliot, Commissariat à l'Energie Atomique, Départment de Biologie, Orsay, France
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