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Tsang DSC, Tsui G, Santiago AT, Keller H, Purdie TG, McIntosh C, La Macchia N, Parent A, Dama H, Ahmed S, Craig T, Laperriere NJ, Millar BA, Hodgson D. A Prospective Study of Machine Learning-Assisted Radiotherapy Planning for Patients Receiving 54 Gy to the Brain. Int J Radiat Oncol Biol Phys 2023; 117:S19. [PMID: 37784448 DOI: 10.1016/j.ijrobp.2023.06.240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Radiotherapy (RT) planning is presently a semi-manual, iterative, labor-intensive process which may result in unnecessary variation in plan quality. To improve treatment plan quality and decrease RT planning time, we conducted a prospective, blinded study to compare machine learning-assisted planning with conventional manual planning for patients receiving 54 Gy in 30 fractions for a primary brain tumor. MATERIALS/METHODS From January 31, 2022 to January 10, 2023, 40 patients receiving 54 Gy for primary CNS tumors were prospectively enrolled (median age 50 years, range 4-78 years). Patients underwent standard CT/MR simulation and target/OAR delineation by the treating radiation oncologist. Each patient had one ML plan and 1-2 manual RT plans created by different planners. The reviewing oncologist was blinded to planning method by removing optimization and IMRT/VMAT beam arrangement details from all plans, which were then rated based on clinical acceptability, target coverage, OAR sparing, conformity, and dose-fall off. One preferred plan was chosen and used for clinical treatment. RESULTS A total of 115 plans for 40 patients were evaluated: 40 ML plans (35% of all plans), and 75 manual plans (65% of all plans; 5 and 35 patients had 1 and 2 manual plans created, respectively). ML plans required a mean planning time of 65 min as compared to 107 min for manual plans, with a mean time savings of 41 min per patient (paired t-test p = 0.002). 97% of ML plans (95% confidence interval [CI] 85-100) and 96% of manual plans (95% CI 87-99) were designated clinically acceptable by the treating radiation oncologist. While ML-assisted plans represented 35% of plans evaluated, they were chosen as preferred for clinical treatment in 43% of cases (17/40, 95% CI 29-58, p = 0.32). Median doses to the brain (10.8 Gy vs. 11.3 Gy, Wilcoxon rank-sum p = 0.012) and brain minus PTV (9.2 Gy vs 10.0 Gy, Wilcoxon rank-sum p = 0.009) were lower with ML planning versus manual planning, respectively. Doses to other structures, including hippocampi, cochlea, pituitary and hypothalamus were not statistically different. CONCLUSION In this prospective study with blinded oncologist evaluation, ML-assisted RT planning for primary CNS tumors was faster than manual planning, and produced a very high rate of acceptable plans with similar or superior OAR sparing. Future work will be undertaken to iteratively refine the ML model using the preferred cases from this study.
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Affiliation(s)
- D S C Tsang
- Radiation Medicine Program, Princess Margaret Cancer Centre and Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - G Tsui
- Princess Margaret Cancer Centre, Toronto, ON, Canada
| | - A T Santiago
- Princess Margaret Cancer Centre, Toronto, ON, Canada
| | - H Keller
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON, Canada
| | | | - C McIntosh
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - N La Macchia
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - A Parent
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - H Dama
- Princess Margaret Cancer Centre, Toronto, ON, Canada
| | - S Ahmed
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - T Craig
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - N J Laperriere
- Radiation Medicine Program, Princess Margaret Cancer Centre and Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - B A Millar
- Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
| | - D Hodgson
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
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Houzé de l'Aulnoit A, Parent A, Boudet S, Rogoz B, Demailly R, Beuscart R, Houzé de l'Aulnoit D. Development of a comprehensive database for research on foetal acidosis. Eur J Obstet Gynecol Reprod Biol 2022; 274:40-47. [PMID: 35580530 DOI: 10.1016/j.ejogrb.2022.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 03/06/2022] [Accepted: 04/09/2022] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To develop a research database for mother-and-child clinical and laboratory data and digital foetal heart rate (FHR) recordings. METHODS The Base Bien Naître (BBN) database was derived from a single-centre health data warehouse. It contains exhaustive data on all parturients with a singleton pregnancy, a vaginal or caesarean delivery in labour with a cephalic presentation after at least 37 weeks of amenorrhea, and a live birth between February 1st, 2011, and December 31st, 2018. On arrival in the delivery room, the FHR was recorded digitally for at least 30 min. A cord blood sample was always taken in order to obtain arterial pH (pHa). More than 6,000 recordings were analyzed visually for the risk of foetal acidosis and classified into five groups (according to the French College of Gynaecologists and Obstetricians (CNGOF) classification) or three groups (according to the International Federation of Gynaecology and Obstetrics (FIGO) classification). RESULTS Of the 16,089 files in the health data warehouse, 11,026 were complete and met the BBN's inclusion criteria. The FHR digital recordings were of good quality, with low signal loss (median [interquartile range]: 7.0% [4.3;10.9]) and a median recording time of 304 min [190;438]). In 3.7% of the children, the pHa was below 7.10. We selected a subset of 6115 records with good-quality FHR recordings over 120 min and reliable cord blood gas data: 692 (11.3%) had at least a significant risk of acidosis (according to the CNGOF classification), and 1638 (26.8%) were at least suspicious (according to the FIGO classification). CONCLUSION The BBN database has been designed as a searchable tool with data reuse. It currently contains over 11,000 records with comprehensive data.
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Affiliation(s)
- A Houzé de l'Aulnoit
- Service Obstétrique, Hôpital Saint-Vincent-de Paul, Institut Catholique de Lille, Boulevard de Belfort, BP 387, F-59020 Lille Cedex, France; Univ Nord de France; CHU Lille, ULR 2694 - METRICS Evaluation des technologies de santé et des pratiques médicales Pôle Recherche, 1 Place de Verdun, F-59045 Lille Cedex, France.
| | - A Parent
- Centre Hospitalier de Valenciennes, Avenue Désandrouin, CS 50479, F-59322 Valenciennes Cedex, France.
| | - S Boudet
- Biomedical Signal Processing Unit (UTSB), Lille Catholic University, 56 Rue du Port, F-59800 Lille, France.
| | - B Rogoz
- Service Obstétrique, Hôpital Saint-Vincent-de Paul, Institut Catholique de Lille, Boulevard de Belfort, BP 387, F-59020 Lille Cedex, France.
| | - R Demailly
- Service Obstétrique, Hôpital Saint-Vincent-de Paul, Institut Catholique de Lille, Boulevard de Belfort, BP 387, F-59020 Lille Cedex, France.
| | - R Beuscart
- Univ Nord de France; CHU Lille, ULR 2694 - METRICS Evaluation des technologies de santé et des pratiques médicales Pôle Recherche, 1 Place de Verdun, F-59045 Lille Cedex, France.
| | - D Houzé de l'Aulnoit
- Service Obstétrique, Hôpital Saint-Vincent-de Paul, Institut Catholique de Lille, Boulevard de Belfort, BP 387, F-59020 Lille Cedex, France.
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Gehenne L, Parent A, Christophe V, Rubod C. [Living with endometriosis, sexual experiences of patients and their partners: A French qualitative study]. ACTA ACUST UNITED AC 2021; 50:69-74. [PMID: 34656789 DOI: 10.1016/j.gofs.2021.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Indexed: 11/29/2022]
Abstract
AIM Endometriosis is a disabling gynecological pathology. Couples who face it frequently encounter sexual difficulties related to dyspareunia. This study aims to understand the sexual experiences of endometriosis patients and their partners. METHODS A total of 13 patients and 13 partners were interviewed prior to surgery. Semi-structured interviews were conducted separately and explored their sexual experiences. The interviews were transcribed verbatim and analyzed using content analysis. RESULTS Both members of the couple reported pain during intercourses; decreased sexual desire; adaptation during sexual intercourses; communication about sexuality, which can be either open or a source of conflict, and the search for explanations for endometriosis. As for the emotional sphere, patients report anticipatory anxiety while partners report frustration and hope. CONCLUSION These couples are in difficulty regarding sexuality, it is necessary to take care of both members of the couple and to encourage communication between them.
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Affiliation(s)
- L Gehenne
- Psychiatrie de liaison et oncologie médicale, hôpital Fontan, CHU de Lille, rue Paul-Nayrac, Lille, France; Université Lille, CNRS, UMR 9193 - SCALab - sciences cognitives et sciences affectives, 59000 Lille, France.
| | - A Parent
- Psychiatrie de liaison et oncologie médicale, hôpital Fontan, CHU de Lille, rue Paul-Nayrac, Lille, France
| | - V Christophe
- Université Lille, CNRS, UMR 9193 - SCALab - sciences cognitives et sciences affectives, 59000 Lille, France
| | - C Rubod
- Service de chirurgie gynécologique, CHU de Lille, 59000 Lille, France; Faculté de médecine, université de Lille, 59000 Lille, France
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Petryszyn S, Saidi L, Gagnon D, Parent A, Parent M. The density of calretinin striatal interneurons is decreased in 6-OHDA-lesioned mice. Brain Struct Funct 2021; 226:1879-1891. [PMID: 34018041 DOI: 10.1007/s00429-021-02298-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 05/08/2021] [Indexed: 11/30/2022]
Abstract
Interneurons play a significant role in the functional organization of the striatum and some of them display marked plastic changes in dopamine-depleted conditions. Here, we applied immunohistochemistry on brain sections from 6-hydroxydopamine (6-OHDA) mouse model of Parkinson's disease and sham animals to characterize the regional distribution and the morphological and neurochemical changes of striatal interneurons expressing the calcium-binding protein calretinin (CR). Two morphological subtypes of calretinin-immunostained (CR +) interneurons referred, respectively, as small- and medium-sized CR + interneurons were detected in 6-OHDA- and sham-lesioned animals. The small cells (9-12 µm) prevail in the anterior and dorsal striatal regions; they stain intensely for CR and display a single slightly varicose and moderately arborized process. The medium-sized CR + interneurons (15-20 µm) are more numerous than the small CR + cells and rather uniformly distributed within the striatum; they stain weakly for CR and display 2-3 long, slightly varicose and poorly branched dendrites. The density of medium CR + interneurons is significantly decreased in the dopamine-depleted striatum (158 ± 15 neurons/mm3), when compared to sham animals (370 ± 41 neurons/mm3), whereas that of the small-sized CR + interneurons is unchanged (174 ± 46 neurons/mm3 in 6-OHDA-lesioned striatum and 164 ± 22 neurons/mm3 in sham-lesioned striatum). The nucleus accumbens is populated only by medium-sized CR + interneurons, which are distributed equally among the core and shell compartments and whose density is unaltered after dopamine denervation. Our results provide the first evidence that the medium-sized striatal interneurons expressing low level of CR are specifically targeted by dopamine denervation, while the small and intensely immunoreactive CR + cells remain unaffected. These findings suggest that high expression of the calcium-binding protein CR might protect striatal interneurons against an increase in intracellular calcium level that is believed to arise from altered glutamate corticostriatal transmission in Parkinson's disease.
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Affiliation(s)
- S Petryszyn
- CERVO Brain Research Center, Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, 2601, Chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - L Saidi
- CERVO Brain Research Center, Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, 2601, Chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - D Gagnon
- CERVO Brain Research Center, Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, 2601, Chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - A Parent
- CERVO Brain Research Center, Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, 2601, Chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - M Parent
- CERVO Brain Research Center, Department of Psychiatry and Neuroscience, Faculty of Medicine, Université Laval, 2601, Chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada.
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Maiezza S, Parent A, Le Deley M, Liem X. Évaluation des pratiques de prise en charge de la mucite orale radiochimio-induite dans les Hauts-de-France. Cancer Radiother 2019. [DOI: 10.1016/j.canrad.2019.07.083] [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: 10/26/2022]
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Bataille B, Le Tinier F, Escande A, Parent A, Bogart E, Narducci F, Leblanc E, Hudry D, Lemaire A, Lesoin A, Chevalier A, Taieb S, Ben Haj Amor M, Lartigau E, Mirabel X, Cordoba A. Intracavitary Preoperative Brachytherapy Followed By Whertheim-Type Hysterectomy in Localized Cervical Cancer: Clinical Data and Toxicity Results from a Single Institution Experience. Int J Radiat Oncol Biol Phys 2019. [DOI: 10.1016/j.ijrobp.2019.06.1796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Petryszyn S, Parent A, Parent M. The calretinin interneurons of the striatum: comparisons between rodents and primates under normal and pathological conditions. J Neural Transm (Vienna) 2017; 125:279-290. [PMID: 28168621 DOI: 10.1007/s00702-017-1687-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 01/22/2017] [Indexed: 12/16/2022]
Abstract
This paper reviews the major organizational features of calretinin interneurons in the dorsal striatum of rodents and primates, with some insights on the state of these neurons in Parkinson's disease and Huntington's chorea. The rat striatum harbors medium-sized calretinin-immunoreactive (CR+) interneurons, whereas the mouse striatum is pervaded by medium-sized CR+ interneurons together with numerous small and highly immunoreactive CR+ cells. The CR interneuronal network is even more elaborated in monkey and human striatum where, in addition to the small- and medium-sized CR+ interneurons, a set of large CR+ interneurons occurs. The majority of these giant CR+ interneurons, which are unique to the primate striatum, also display immunoreactivity for choline acetyltransferase (ChAT), a faithful marker of cholinergic neurons. The expression of CR and/or ChAT by the large striatal interneurons appears to be seriously compromised in Parkinson's disease and Huntington's chorea. The species differences noted above have to be considered to better understand the role of CR interneurons in striatal organization in both normal and pathological conditions.
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Affiliation(s)
- S Petryszyn
- Department of Psychiatry and Neuroscience, Faculty of Medicine, Centre de recherche de l'Institut universitaire en santé mentale de Québec, Université Laval, 2601, Canardière, Room F-6500, Quebec, QC, G1J 2G3, Canada
| | - A Parent
- Department of Psychiatry and Neuroscience, Faculty of Medicine, Centre de recherche de l'Institut universitaire en santé mentale de Québec, Université Laval, 2601, Canardière, Room F-6500, Quebec, QC, G1J 2G3, Canada
| | - Martin Parent
- Department of Psychiatry and Neuroscience, Faculty of Medicine, Centre de recherche de l'Institut universitaire en santé mentale de Québec, Université Laval, 2601, Canardière, Room F-6500, Quebec, QC, G1J 2G3, Canada.
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Gagnon D, Petryszyn S, Sanchez MG, Bories C, Beaulieu JM, De Koninck Y, Parent A, Parent M. Striatal Neurons Expressing D 1 and D 2 Receptors are Morphologically Distinct and Differently Affected by Dopamine Denervation in Mice. Sci Rep 2017; 7:41432. [PMID: 28128287 PMCID: PMC5269744 DOI: 10.1038/srep41432] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/19/2016] [Indexed: 12/11/2022] Open
Abstract
The loss of nigrostriatal dopamine neurons in Parkinson’s disease induces a reduction in the number of dendritic spines on medium spiny neurons (MSNs) of the striatum expressing D1 or D2 dopamine receptor. Consequences on MSNs expressing both receptors (D1/D2 MSNs) are currently unknown. We looked for changes induced by dopamine denervation in the density, regional distribution and morphological features of D1/D2 MSNs, by comparing 6-OHDA-lesioned double BAC transgenic mice (Drd1a-tdTomato/Drd2-EGFP) to sham-lesioned animals. D1/D2 MSNs are uniformly distributed throughout the dorsal striatum (1.9% of MSNs). In contrast, they are heterogeneously distributed and more numerous in the ventral striatum (14.6% in the shell and 7.3% in the core). Compared to D1 and D2 MSNs, D1/D2 MSNs are endowed with a smaller cell body and a less profusely arborized dendritic tree with less dendritic spines. The dendritic spine density of D1/D2 MSNs, but also of D1 and D2 MSNs, is significantly reduced in 6-OHDA-lesioned mice. In contrast to D1 and D2 MSNs, the extent of dendritic arborization of D1/D2 MSNs appears unaltered in 6-OHDA-lesioned mice. Our data indicate that D1/D2 MSNs in the mouse striatum form a distinct neuronal population that is affected differently by dopamine deafferentation that characterizes Parkinson’s disease.
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Affiliation(s)
- D Gagnon
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada
| | - S Petryszyn
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada
| | - M G Sanchez
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada
| | - C Bories
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada
| | - J M Beaulieu
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada
| | - Y De Koninck
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada
| | - A Parent
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada
| | - M Parent
- Centre de recherche de l'Institut universitaire en santé mentale de Québec, Department of Psychiatry and Neuroscience, Faculty of medicine, Université Laval, Quebec City, QC, Canada
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Samadi B, Achiche S, Parent A, Ballaz L, Chouinard U, Raison M. Custom sizing of lower limb exoskeleton actuators using gait dynamic modelling of children with cerebral palsy. Comput Methods Biomech Biomed Engin 2016; 19:1519-24. [PMID: 26980164 DOI: 10.1080/10255842.2016.1159678] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The use of exoskeletons as an aid for people with musculoskeletal disorder is the subject to an increasing interest in the research community. These devices are expected to meet the specific needs of users, such as children with cerebral palsy (CP) who are considered a significant population in pediatric rehabilitation. Although these exoskeletons should be designed to ease the movement of people with physical shortcoming, their design is generally based on data obtained from healthy adults, which leads to oversized components that are inadequate to the targeted users. Consequently, the objective of this study is to custom-size the lower limb exoskeleton actuators based on dynamic modeling of the human body for children with CP on the basis of hip, knee, and ankle joint kinematics and dynamics of human body during gait. For this purpose, a multibody modeling of the human body of 3 typically developed children (TD) and 3 children with CP is used. The results show significant differences in gait patterns especially in knee and ankle with respectively 0.39 and -0.33 (Nm/kg) maximum torque differences between TD children and children with CP. This study provides the recommendations to support the design of actuators to normalize the movement of children with CP.
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Affiliation(s)
- B Samadi
- a Rehabilitation Engineering Chair Applied to Pediatrics , École Polytechnique de Montréal and CRME - Ste-Justine UHC , Montreal , Canada
| | - S Achiche
- b Department of Mechanical Engineering , École Polytechnique de Montréal , Montreal , Canada
| | - A Parent
- a Rehabilitation Engineering Chair Applied to Pediatrics , École Polytechnique de Montréal and CRME - Ste-Justine UHC , Montreal , Canada
| | - L Ballaz
- c Department of Physical Activity Sciences , Université du Québec à Montréal (UQAM) and CRME - Ste-Justine UHC , Montreal , Canada
| | - U Chouinard
- b Department of Mechanical Engineering , École Polytechnique de Montréal , Montreal , Canada
| | - M Raison
- a Rehabilitation Engineering Chair Applied to Pediatrics , École Polytechnique de Montréal and CRME - Ste-Justine UHC , Montreal , Canada.,b Department of Mechanical Engineering , École Polytechnique de Montréal , Montreal , Canada
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Dickie C, Parent A, Chung P, Catton C, Ferguson P, Wunder J, O'Sullivan B. SP-0115: Adaptive treatment planning in soft tissue sarcoma: Why and when is it necessary? Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)40113-6] [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: 11/25/2022]
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Parent A, Pouliot-Laforte A, Laberge M, Hamdy R, Rochelle R, Ballaz L. Articulated vs. fixed carbon-fibre prosthesis after transmetatarsial amputation: a case study. Comput Methods Biomech Biomed Engin 2014; 17 Suppl 1:106-7. [PMID: 25074187 DOI: 10.1080/10255842.2014.931384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- A Parent
- a Sainte-Justine UHC , Montreal , Canada
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Pouliot-Laforte A, Parent A, Ballaz L. Walking efficiency in children with cerebral palsy: relation to muscular strength and gait parameters. Comput Methods Biomech Biomed Engin 2014; 17 Suppl 1:104-5. [PMID: 25074186 DOI: 10.1080/10255842.2014.931340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- A Pouliot-Laforte
- a Département de kinanthropologie , Université du Québec à Montréal , Montreal , Canada
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King W, Campbell C, Parent A, Parker K. 105: EMR Readiness Assessment at a Tertiary Care Paediatric Hospital. Paediatr Child Health 2014. [DOI: 10.1093/pch/19.6.e35-103] [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: 11/13/2022] Open
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Dickie C, Parent A, Grant K, Sharpe M, Griffin A, Catton C, Chung P, Ferguson P, Wunder J, O'Sullivan B. Dosimetric Consequences of Tumor Volume Changes During Preoperative IMRT for Lower Extremity Soft Tissue Sarcoma. Int J Radiat Oncol Biol Phys 2013. [DOI: 10.1016/j.ijrobp.2013.06.166] [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: 10/26/2022]
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Letellier G, Parent A, Raison M, Marois P, Mercier C, Crevier L, Laberge M, Ballaz L. Radicellectomie sensitive partielle basée sur des observations cliniques : description des critères de décision et effet sur la marche des enfants avec paralysie cérébrale. Ann Phys Rehabil Med 2013. [DOI: 10.1016/j.rehab.2013.07.764] [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: 11/28/2022]
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Letellier G, Parent A, Raison M, Marois P, Mercier C, Crevier L, Laberge M, Ballaz L. Twenty-five years of selective dorsal rhizotomy based on clinical observations instead of intraoperative electrophysiological monitoring: The Sainte-Justine hospital experience. Ann Phys Rehabil Med 2013. [DOI: 10.1016/j.rehab.2013.07.772] [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: 10/26/2022]
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Al-Omair A, Masucci L, Masson L, Campbell M, Atenafu E, Parent A, Letourneau D, Yu E, Fehlings M, Sahgal A. Postoperative Stereotactic Body Radiation Therapy (SBRT) for Patients With Spinal Metastasis: Predictive and Prognostic Factors Analysis. Int J Radiat Oncol Biol Phys 2013. [DOI: 10.1016/j.ijrobp.2013.06.690] [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: 10/26/2022]
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St-Louis J, Massicotte G, Parent A. Effet anti-hypertenseur de la grossesse : influence de la réactivite vasculaire. ACTA ACUST UNITED AC 2013. [DOI: 10.4267/10608/3833] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wyndaele JJ, Parent A. Dr Albert Tricot. Spinal Cord 2011. [DOI: 10.1038/sc.2010.108] [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: 11/09/2022]
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Bahl G, Urbach S, Bartels U, Hodgson D, Millar B, Parent A, Le L, Awrey S, Laperriere N. 74 LATE ENDOCRINE TOXICITY OF RADIATION THERAPY IN CHILDREN TREATED FOR MEDULLOBLASTOMA OR EPENDYMOMA. Radiother Oncol 2009. [DOI: 10.1016/s0167-8140(12)72461-1] [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: 10/27/2022]
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Parent A, Leroy S, Christophe V, Vanneste J, Delelis G, Perez T, Antoine P, Wallaert B. Pilot study: impact of Cystic Fibrosis on emotional and marital satisfaction. J Cyst Fibros 2009. [DOI: 10.1016/s1569-1993(09)60351-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bahl G, Urbach S, Bartels U, Hodgson DC, Millar B, Parent A, Le L, Awrey S, Laperriere N. Endocrine complications in children treated for medulloblastoma or ependymoma using radiation therapy. Outcomes in the CT-planning era. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.10064] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
10064 Background: The purpose of this study is to determine the frequency of late endocrine complications following radiation therapy (RT) in children treated for medulloblastomas or ependymomas. Methods: Seventy children with medulloblastoma or ependymoma were treated using RT from June 2000 to June 2005 at our institute. Median age at diagnosis was 6 years (range 1–17), and 52 (74%) were boys. Forty-eight patients (69%) had medulloblastomas and 22 (31%) had ependymomas. Twenty-two received highly conformal RT to the tumor bed alone (focal RT: median dose 54 Gy, range 54–59.4), 24 received low dose cranio-spinal RT (CSI: median dose 23.4 Gy) followed by a boost to the post fossa/tumor bed (median 30.6 Gy), and 24 patients received high dose CSI (median 36 Gy) followed by a boost (median 18 Gy). Only two of the 22 children with ependymomas received CSI. All patients underwent CT-based planning and were treated using conventional fractionation; 58 (83%) also received chemotherapy. None of the children had documented endocrinopathy prior to diagnosis. Results: After a median follow-up of 65.3 months, the 5-yr PFS and OS was 70% and 75% for children with medulloblastomas, and 54% and 84% for patients with ependymomas, respectively. Thirty-five children developed evidence of endocrinopathy (Growth hormone deficiency (GHD): 31, hypothyroidism (HPT): 23, precocious puberty (PP): 6, gonadotropin deficiency: 3, ACTH deficiency: 2, and diabetes insipidus: 2). The 5-yr cumulative incidence (CI) of endocrinopathy was 71% for the children treated with CSI vs. 18% for those treated with focal RT (Gray's test p-value = 0.004). The median time to development of endocrinopathy was 38 months for the patients who had CSI. For these children the 5-yr CI was 68% for GHD, 52% for HPT, and 16% for PP. There was no significant difference in the incidence of endocrinopathy for patients treated with low dose vs. high dose CSI. Conclusions: The 5-yr CI of endocrine toxicity in children treated with cranio-spinal RT is 71% (median time to development: 38 months), which is significantly higher than in children treated with focal RT. All children treated for medulloblastomas or ependymomas require long-term surveillance and close monitoring for the development of endocrinopathies. No significant financial relationships to disclose.
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Affiliation(s)
- G. Bahl
- Princess Margaret Hospital/University Health Net, Toronto, ON, Canada; The Hospital for Sick Children, Toronto, ON, Canada
| | - S. Urbach
- Princess Margaret Hospital/University Health Net, Toronto, ON, Canada; The Hospital for Sick Children, Toronto, ON, Canada
| | - U. Bartels
- Princess Margaret Hospital/University Health Net, Toronto, ON, Canada; The Hospital for Sick Children, Toronto, ON, Canada
| | - D. C. Hodgson
- Princess Margaret Hospital/University Health Net, Toronto, ON, Canada; The Hospital for Sick Children, Toronto, ON, Canada
| | - B. Millar
- Princess Margaret Hospital/University Health Net, Toronto, ON, Canada; The Hospital for Sick Children, Toronto, ON, Canada
| | - A. Parent
- Princess Margaret Hospital/University Health Net, Toronto, ON, Canada; The Hospital for Sick Children, Toronto, ON, Canada
| | - L. Le
- Princess Margaret Hospital/University Health Net, Toronto, ON, Canada; The Hospital for Sick Children, Toronto, ON, Canada
| | - S. Awrey
- Princess Margaret Hospital/University Health Net, Toronto, ON, Canada; The Hospital for Sick Children, Toronto, ON, Canada
| | - N. Laperriere
- Princess Margaret Hospital/University Health Net, Toronto, ON, Canada; The Hospital for Sick Children, Toronto, ON, Canada
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Wolak A, Novella JL, Guillemin F, Toussaint É, Marchand A, Collart M, Parent A, Morrone I, Blanchard F, Jolly D. Adaptation transculturelle et validation psychométrique du Quality of Life in Alzheimer's Disease (QoL-AD) en version française. Rev Epidemiol Sante Publique 2009. [DOI: 10.1016/j.respe.2009.02.201] [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: 10/20/2022] Open
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Dickie-Euler C, Parent A, Griffin A, Chung P, Catton C, Craig T, Sharpe M, O'Sullivan B. Measuring Interfraction and Intrafraction Motion with Cone Beam Computed Tomography (CBCT) and an Optical Localization System (OLS) for Lower Extremity Soft Tissue Sarcoma Patients Treated with Preoperative Intensity Modulated Radiation Therapy (IMRT). Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.1005] [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: 10/21/2022]
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VanLandingham M, Nguyen T, Roberts A, Parent A, Zhang J. O.062 Risk factors for familial and sporadic congenital hydrocephalus. Clin Neurol Neurosurg 2008. [DOI: 10.1016/s0303-8467(08)70067-2] [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: 10/21/2022]
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La Macchia N, Tsang R, Parent A, Heaton R, Cheung F, van Prooijen M, Amin N, Islam M. The Development of a Segmented Intensity Modulated Beam Technique for Total Body Irradiation Prior to Hematologic Stem Cell Transplantation. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.07.1783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Parent A, Craig T, La Macchia N, Lau M, Vergel De Dios D, Sharpe M, Tsang R, Toronto Lymphoma Group. Setup Uncertainty and Planning Target Volume Margin for Thoracic Lymphoma Patients: Value of Cone Beam CT Image Guidance. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.07.1782] [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: 10/22/2022]
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Euler C, Parent A, Griffin A, Sharpe M, Chung P, Catton C, O'Sullivan B. Bone Fractures Following External Beam Radiotherapy and Limb-Preservation Surgery for Extremity Soft Tissue Sarcoma: Relationship to Irradiated Bone Length, Volume and Dose. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.07.2303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zeng GG, Heaton RK, Catton CN, Chung PW, O'Sullivan B, Lau M, Parent A, Jaffray DA. A two isocenter IMRT technique with a controlled junction dose for long volume targets. Phys Med Biol 2007; 52:4541-52. [PMID: 17634649 DOI: 10.1088/0031-9155/52/15/012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Most IMRT techniques have been designed to treat targets smaller than the field size of conventional linac accelerators. In order to overcome the field size restrictions in applying IMRT, we developed a two isocenter IMRT technique to treat long volume targets. The technique exploits an extended dose gradient throughout a junction region of 4-6 cm to minimize the impact of field match errors on a junction dose and manipulates the inverse planning and IMRT segments to fill in the dose gradient and achieve dose uniformity. Techniques for abutting both conventional fields with IMRT ('Static + IMRT') and IMRT fields ('IMRT + IMRT') using two separate isocenters have been developed. Five long volume sarcoma cases have been planned in Pinnacle (Philips, Madison, USA) using Elekta Synergy and Varian 2100EX linacs; two of the cases were clinically treated with this technique. Advantages were demonstrated with well-controlled junction target uniformity and tolerance to setup uncertainties. The junction target dose heterogeneity was controlled at a level of +/-5%; for 3 mm setup errors at the field edges, the junction target dose changed less than 5% and the dose sparing to organs at risk (OARs) was maintained. Film measurements confirmed the treatment planning results.
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Affiliation(s)
- G G Zeng
- Radiation Medicine Program, Princess Margaret Hospital/University Health Network, Toronto M5G 2M9, Canada.
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31
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Beggah A, Parent A, Pertin M, Bonny C, Pellerin L, Ji R, Decosterd I. 341 NEUROPATHIC PAIN AND SPINAL GLIA: CHARACTERIZATION OF C-JUN N-TERMINAL KINASE (JNK) ACTIVATION IN ASTROCYTE CULTURES. Eur J Pain 2007. [DOI: 10.1016/j.ejpain.2007.03.356] [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: 10/23/2022]
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Ahmad S, Aaltonen LA, Georgitsi M, Parent A, Fratkin J, McMillan T, Gomez-Sanchez E, Koch CA. Do single nucleotide polymorphisms in the AIP and MEN1 genes predispose individuals to the development of familial isolated pituitary adenomas? Exp Clin Endocrinol Diabetes 2007. [DOI: 10.1055/s-2007-972334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
In this paper we evaluate the hypothesis of a possible link between the degree of axonal collateralization of neurons located within the different components of basal ganglia and the vulnerability of these neurons to neurodegenerative or neurotoxic events. Our results stemmed from single-cell labeling experiments in rodents and primates, immunohistochemical study of the dopaminergic nigrostriatal pathway in parkinsonian monkeys, and immunocytological analysis of the human striatum in normal individuals and in patients with Huntington's disease. Our results indicate that projection neurons within virtually all basal ganglia components are endowed with a widespread and highly collateralized axon that yields a fixed number of terminals. Such a high degree of axonal collateralization allows exquisitely precise interactions between the various basal ganglia nuclei. However, the maintenance of this unique morphological trait implies high-energy consumption and renders basal ganglia neurons highly vulnerable to neurodegenerative, metabolic or neurotoxic insults.
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Affiliation(s)
- M Parent
- Centre de recherche Université Laval Robert-Giffard, Beauport, Québec, Canada
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Quesenberry P, Colvin G, Lambert JF, Abedi M, Cerny J, Dooner M, Moore B, McAuliffe C, Demers D, Greer D, Parent A, Badiavas E, Lum L, Falanga V. Marrow stem cell potential within a continuum. Ann N Y Acad Sci 2003; 996:209-21. [PMID: 12799298 DOI: 10.1111/j.1749-6632.2003.tb03248.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
On the basis of our studies of the fluctuation of the hematopoietic stem cell phenotype with cell cycle trnsit, we hypothesize that the ability of marrow stem cells to convert to nonhematopoietic cells will also vary at different points in the cell cycle. The new biology of stem cells has an impact on many fields including developmental biology and stem cell biology and the clinical potential is enormous.
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Affiliation(s)
- P Quesenberry
- The Research Department, Roger Williams Medical Center, Providence, Rhode Island 02908, USA.
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Parent A, Cossette M. Extrastriatal dopamine and Parkinson's disease. Adv Neurol 2002; 86:45-54. [PMID: 11554008] [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] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Affiliation(s)
- A Parent
- Laboratoire de Neurobiologie, Hôpital Robert-Giffard, Beauport, Québec G1J 2G3, Canada
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37
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Weaver IC, La Plante P, Weaver S, Parent A, Sharma S, Diorio J, Chapman KE, Seckl JR, Szyf M, Meaney MJ. Early environmental regulation of hippocampal glucocorticoid receptor gene expression: characterization of intracellular mediators and potential genomic target sites. Mol Cell Endocrinol 2001; 185:205-18. [PMID: 11738810 DOI: 10.1016/s0303-7207(01)00635-9] [Citation(s) in RCA: 84] [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: 11/22/2022]
Abstract
Environmental conditions in early life permanently alter the development of glucocorticoid receptor gene expression in the hippocampus and hypothalamic-pituitary-adrenal responses to acute or chronic stress. In part, these effects can involve an activation of ascending serotonergic pathways and subsequent changes in the expression of transcription factors that might drive glucocorticoid receptor expression in the hippocampus. This paper summarizes the evidence in favor of these pathways as well as recent studies describing regulatory targets on the promoter region of the rat hippocampal glucocorticoid receptor gene.
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Affiliation(s)
- I C Weaver
- McGill program for the Study of Behavior, Genes and Environment, Douglas Hospital Research Centre, Department of Psychiatry, McGill University, 6875 LaSalle Blvd., Montreal, Quebec, Canada H4H 1R3
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Parent A. [Not Available]. Wurzbg Medizinhist Mitt 2001; 7:169-77. [PMID: 11631205] [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: 02/21/2023]
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Parent M, Lévesque M, Parent A. Two types of projection neurons in the internal pallidum of primates: single-axon tracing and three-dimensional reconstruction. J Comp Neurol 2001; 439:162-75. [PMID: 11596046 DOI: 10.1002/cne.1340] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.1] [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: 11/09/2022]
Abstract
The axonal projections of the internal pallidum (GPi) in cynomolgus monkeys (Macaca fascicularis) were studied by labeling small pools of neurons with biotinylated dextran amine. Fifty-two axons were reconstructed entirely from serial sections with a camera lucida. Two types of projection neurons were identified in the GPi on the basis of their target sites. The abundant and centrally located type I neurons gave rise to a long axonal branch that descended directly to the pedunculopontine tegmental nucleus, where it arborized discretely. Other branches ascended to the thalamus and broke into 10-15 thinner collaterals that ran through most of the ventral anterior nucleus, where they terminated as typical plexuses. About half of these axons gave rise to collaterals that arborized in both components of the centre médian/parafascicular thalamic complex. The less numerous and peripherally located type II neurons had an axon that climbed the rostral thalamic pole, coursed along the stria medullaris, and arborized profusely within the lateral habenular nucleus, which stood out as the most densely innervated pallidal target. Some type II axons provided collaterals to the anterior thalamic nuclei. A small proportion of axons of both types had branches that crossed the midline and terminated in contralateral GPi target structures. Three-dimensional reconstruction showed that type I axons arborized principally along the sagittal plane. These data reveal that GPi neurons of type I act through a widely distributed axonal network upon thalamic and brainstem premotor neurons, whereas type II neurons act in a much more focused manner upon lateral habenular neurons.
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Affiliation(s)
- M Parent
- Centre de recherche Université Laval Robert-Giffard, 2601, Chemin de la Canardière, Beauport, Québec, Canada, G1J 2G3
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Prensa L, Parent A. The nigrostriatal pathway in the rat: A single-axon study of the relationship between dorsal and ventral tier nigral neurons and the striosome/matrix striatal compartments. J Neurosci 2001; 21:7247-60. [PMID: 11549735 PMCID: PMC6762986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
Axons from dorsal/ventral tiers of substantia nigra pars compacta (SNc), ventral tegmental area (VTA), and retrorubral field (RRF) were traced after injecting their cell body with biotinylated dextran amine. Fifty-three single axons were reconstructed from serial sagittal sections with a camera lucida, and mu-opiate receptor immunostaining served to differentiate the striosome/matrix striatal compartments. Most dorsal tier SNc axons terminate within the matrix of the dorsal striatum, but their patterns of arborization vary markedly; some axons innervate one specific matriceal area, whereas others arborize in multiple discontinuous loci. Some dorsal tier SNc axons also project to both striosomes and matrix. Other dorsal tier SNc axons, as well as VTA axons, innervate the ventral striatum and send collaterals to striosomes lying ventrally in the dorsal striatum or to the ventral sector of the subcallosal streak (SS). Ventral tier SNc axons arborize principally in striosomes, but some ramify in both compartments or in striosomes and the SS. Ventral tier neurons that form deep clusters in substantia nigra pars reticulata innervate principally the matrix and the SS. The amygdala and ventral pallidum receive secondary collaterals from striatal axons of dorsal/ventral tier neurons or RRF neurons. The subthalamic nucleus receives collaterals from striatal axons of SNc clustered neurons, whereas the globus pallidus gets collaterals from striatal axons of dorsal/ventral tier SNc neurons. These findings reveal that the nigrostriatal pathway is composed of several neuronal subsystems, each endowed with a widely distributed axonal arborization that allows them to exert a multifaceted influence on striatal and/or extrastriatal structures.
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Affiliation(s)
- L Prensa
- Centre de Recherche Université Laval Robert-Giffard, Local F-6500, Beauport, Québec, Canada, G1J 2G3
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Abstract
The current model of basal ganglia organization has been developed progressively over the last two decades in the light of key observations made at both experimental and clinical levels. This model has been highly successful in that it has stimulated a large amount of research in the field. However, several experimental and clinical findings that are at odds with the model have accumulated during the last decade. This paper reviews some of our own single-axon tracing studies in primates, which call for a re-evaluation of the current basal ganglia model.
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Affiliation(s)
- A Parent
- Laboratoire de Neurobiologie, Centre de recherche Université Laval Robert-Giffard, 2601, de la Canardière, Que., G1J 2G3, Beauport, Canada
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Zarate-Lagunes M, Gu WJ, Blanchard V, Francois C, Muriel MP, Mouatt-Prigent A, Bonici B, Parent A, Hartmann A, Yelnik J, Boehme GA, Pradier L, Moussaoui S, Faucheux B, Raisman-Vozari R, Agid Y, Brice A, Hirsch EC. Parkin immunoreactivity in the brain of human and non-human primates: an immunohistochemical analysis in normal conditions and in Parkinsonian syndromes. J Comp Neurol 2001; 432:184-96. [PMID: 11241385 DOI: 10.1002/cne.1096] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The etiology of Parkinson's disease is unknown, but the gene involved in an autosomic recessive form of the disease with early onset has recently been identified. It codes for a protein with an unknown function called parkin. In the present study we produced a specific polyclonal antiserum against human parkin. Immunohistochemical analysis showed that parkin is expressed in neuronal perikarya and processes but also in glial and blood vessels in the primate brain (human and monkey). Electron microscopy indicated that parkin immunoreactivity is mostly located in large cytoplasmic vesicles and at the level of the endoplasmic reticulum. Parkin was expressed heterogeneously in various structures of the brain. It was detectable in the dopaminergic systems at the level of the perikarya in the mesencephalon but also in the striatum. However, parkin was also expressed by numerous nondopaminergic neurons. The staining intensity of parkin was particularly high in the hippocampal formation, the pallidal complex, the red nucleus, and the cerebellum. Comparison of control subjects with patients with Parkinson's disease and control animals with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated animals revealed a loss of parkin-immunoreactive neurons only in the substantia nigra pars compacta. Furthermore, the surviving dopaminergic neurons in the parkinsonian state continued to express parkin at a level similar to that observed in the control situation. These data indicate that parkin is a widely expressed protein. Thus, the degeneration of dopaminergic neurons in familial cases of Parkinson's disease with autosomal recessive transmission cannot be explained solely in terms of an alteration of this protein.
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Affiliation(s)
- M Zarate-Lagunes
- INSERM U 289, Hôpital de la Salpêtrière, 47 Bd. de l'Hôpital, 75013 Paris, France
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Parent A, Walker ML, Whitehead WE, Boyer R, Townsend J. A 14-year-old female with decreasing visual acuity, severe headache, nausea and vomiting. Pediatr Neurosurg 2001; 34:47-52. [PMID: 11275788 DOI: 10.1159/000055993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- A Parent
- Department of Neurosurgery, University of Hospital and Clinics, University of Mississippi Medical Center, Jackson 39216-4505, USA
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Abstract
This paper summarises the results of some of our recent tyrosine hydroxylase (TH) immunohistochemical studies of the dopaminergic innervation of the human basal ganglia. It also reports new findings on the presence of TH-immunoreactive (ir) neurons in the striatum. Our data show the existence of nigrostriatal TH-ir axons that provide collaterals arborizing in the globus pallidus and subthalamic nucleus. These thin and varicose collaterals emerge from thick and smooth axons that course along the main output pathways of the basal ganglia, including the ansa lenticularis, the lenticular fasciculus and Wilson's pencils. We postulate that this extrastriatal innervation, which allows nigral dopaminergic neurons to directly affect the pallidum and subthalamic nucleus, plays a critical role in the functional organisation of human basal ganglia. The TH-ir fibres that reach the striatum arborize according to a highly heterogeneous pattern. At rostral striatal levels, numerous small TH-poor zones embedded in a TH-rich matrix correspond to calbindin-poor striosomes and calbindin-rich extrastriosomal matrix, respectively. At caudal striatal levels, in contrast, striosomes display a TH immunostaining that is more intense than that of the matrix. A significant number of small, oval, aspiny TH-ir neurons scattered throughout the rostrocaudal extent of the caudate nucleus and putamen, together with a few larger, multipolar, spiny TH-ir neurons lying principally within the ventral portion of the putamen, were disclosed in human. This potential source of intrinsic striatal dopamine might play an important role in the functional organisation of the human striatum, particularly in case of Parkinson's disease.
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Affiliation(s)
- L Prensa
- Laboratoire de Neurobiologie, Centre de recherche Université Laval Robert-Giffard, 2601, de la Canardière, Local F-6500, Quebec, Beauport, Canada G1J 2G3
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Tibbs R, Zubkov A, Aoki K, Meguro T, Badr A, Parent A, Zhang J. Effects of mitogen-activated protein kinase inhibitors on cerebral vasospasm in a double-hemorrhage model in dogs. J Neurosurg 2000; 93:1041-7. [PMID: 11117847 DOI: 10.3171/jns.2000.93.6.1041] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Mitogen-activated protein kinase (MAPK) may be involved in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage. This study was conducted to investigate the ability of the MAPK inhibitors PD-98059 and U-0126 to reverse vasospasm in a double-hemorrhage model in dogs. METHODS Twenty-two adult mongrel dogs of either sex, each weighing 18 to 24 kg, were divided randomly into four groups: control SAH (four dogs), vehicle- (dimethyl sulfoxide, six dogs), PD-98059- (six dogs), and U-0126-treated groups (six dogs). The double-hemorrhage model was created by an autologous blood injection into the cisterna magna on Days 0 and 2. An intracisternal injection of MAPK inhibitors was administered once per day on Days 3 through 6. Cerebral angiography was performed on Days 0 and 7 before the animals were killed. Western blot analysis was used to study the effects of hemorrhage and drug treatment on the MAPK immunoprecipitation. Severe vasospasm developed in the dogs in the control and vehicle-treated groups (basilar artery [BA] diameter reduction 46.6 +/- 5.5% and 49.3 +/- 4.6%, respectively). In the PD-98059-treated group, most of the dogs developed mild vasospasm (18.9 +/- 6.2%). In the U-0126-treated group, severe vasospasm was observed despite treatment (39.6 +/- 6.4%). The PD-98059 but not the U-0126 abolished MAPK immunoprecipitation in the spastic BAs. However, treatment with either PD-98059 or U-0126 improved the clinical scores of the dogs. CONCLUSIONS The present study is the first in which the effects of MAPK inhibitors on vasospasm have been investigated in vivo. The authors demonstrate that MAPK may play a role in vasospasm and that PD-98059 is a potential candidate for the treatment of cerebral vasospasm.
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Affiliation(s)
- R Tibbs
- Department of Neurosurgery, University of Mississippi Medical Center, Jackson 39216-4505, USA
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Cicchetti F, Prensa L, Wu Y, Parent A. Chemical anatomy of striatal interneurons in normal individuals and in patients with Huntington's disease. Brain Res Brain Res Rev 2000; 34:80-101. [PMID: 11086188 DOI: 10.1016/s0165-0173(00)00039-4] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
This paper reviews the major anatomical and chemical features of the various types of interneurons in the human striatum, as detected by immunostaining procedures applied to postmortem tissue from normal individuals and patients with Huntington's disease (HD). The human striatum harbors a highly pleomorphic population of aspiny interneurons that stain for either a calcium-binding protein (calretinin, parvalbumin or calbindin D-28k), choline acetyltransferase (ChAT) or NADPH-diaphorase, or various combinations thereof. Neurons that express calretinin (CR), including multitudinous medium and a smaller number of large neurons, are by far the most abundant interneurons in the human striatum. The medium CR+ neurons do not colocalize with any of the known chemical markers of striatal neurons, except perhaps GABA, and are selectively spared in HD. Most large CR+ interneurons display ChAT immunoreactivity and also express substance P receptors. The medium and large CR+ neurons are enriched with glutamate receptor subunit GluR2 and GluR4, respectively. This difference in AMPA GluR subunit expression may account for the relative resistance of medium CR+ neurons to glutamate-mediated excitotoxicity that may be involved in HD. The various striatal chemical markers display a highly heterogeneous distribution pattern in human. In addition to the classic striosomes/matrix compartmentalization, the striosomal compartment itself is composed of a core and a peripheral region, each subdivided by distinct subsets of striatal interneurons. A proper knowledge of all these features that appear unique to humans should greatly help our understanding of the organization of the human striatum in both health and disease states.
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Affiliation(s)
- F Cicchetti
- Centre de Recherche Université Laval Robert-Giffard, 2601 Chemin de la Canardière, Local F-6500, Québec, G1J 2G3, Beauport, Canada
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Abstract
Recent neuroanatomical data obtained with single-axon or single-cell labeling procedures in both rodents and primates have revealed the presence of various types of projection neurons with profusely collateralized axons within each of the major components of the basal ganglia. Such findings call for a reappraisal of current concepts of the anatomical and functional organization of the basal ganglia,which play such a crucial role in the control of motor behavior. The basal ganglia now stand as a widely distributed neuronal network, whose elements are endowed with a highly patterned set of axon collaterals. The elucidation of this finely tuned network is needed to understand the complex spatiotemporal sequence of neural events that ensures the flow of cortical information through the basal ganglia.
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Affiliation(s)
- A Parent
- Centre de recherche Université Laval Robert-Giffard, Beauport, Québec, Canada
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Abstract
Cerebral vasospasm is the major factor of mortality and morbidity in the patients who have an aneurysmal subarachnoid hemorrhage (SAH). Erythrocyte lysate (hemolysate), oxyhemoglobin (OxyHb), and bloody cerebrospinal fluid (CSF) are the causative agents for vasospasm. However, the signal transduction pathways for the action of these spasmogens are not clear. In this study, we examined the possible effect of these spasmogens on the p21Ras protein, an important factor in the signal cascade, in rabbit basilar artery. Hemolysate enhanced p21Ras precipitation over a 7-day period. The initial increase of p21Ras precipitation occurred after the tissues were incubated for 2 days with hemolysate. The peak effect of hemolysate, which was markedly increased compared with control (P<0.05, ANOVA), was observed on day 3. OxyHb and blood CSF, in contrast, failed to produce consistent or marked changes in p21Ras precipitation. p21Ras inhibitors FTPase inhibitor 1 and manumycin abolished hemolysate-induced enhancement of p21Ras immunoprecipitation. Genistein, a tyrosine kinase inhibitor, failed to reduce the effect of hemolysate on p21Ras. We concluded that hemolysate activates p21Ras in the rabbit basilar artery.
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Affiliation(s)
- A Patlolla
- Department of Neurosurgery, University of Mississippi Medical Center, Jackson 39216, USA
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Abstract
The aim of the present study was to provide a detailed account of the axonal branching pattern of striatal projection neurons in the rat. Seventy-seven striatofugal neurons were singly labeled following juxtacellular injection of biotin dextran amine. Their axons were entirely reconstructed along the sagittal plane with the help of a light microscope equipped with a camera lucida. The major findings of this study can be summarized as follows, (1) the striatofugal system originates from medium-sized spiny neurons that project only to globus pallidus (GP, type I, 36.4%), to both GP and substantia nigra pars reticulata (SNr, type II, 26%), or to globus pallidus, entopeduncular nucleus (EP) and SNr (type III, 37.6%); (2) the striatofugal system displays a high degree of axonal collateralization; about two-thirds of its axons arborize into two or three striatal target structures; (3) virtually all striatofugal axons send collaterals to the GP and none project exclusively to the EP and or SNr; (4) the three types of striatal projection neurons share similar somatodendritic morphology and have no preferential distribution in the dorsal striatum. These data, together with those of previous investigations, indicate that the striatofugal system can no longer be considered to be a simple dual (direct indirect) projection system. Instead, it stands out as a complex and widely distributed neuronal network whose elements are endowed with a highly patterned set of axon collaterals, which allows them to control in an exquisitely precise manner the flow of information along the main axis of the basal ganglia.
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Affiliation(s)
- Y Wu
- Laboratoire de Neurobiologie, Centre de Recherche Université Laval Robert-Gifford, Beauport, Quebec, Canada
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Abstract
Axonal projections arising from the subthalamic nucleus (STN) in cynomolgus monkeys (Macaca fascicularis) were traced after labeling small pools (5-15 cells) of neurons with biotinylated dextran amine. Seventy-five single axons were reconstructed from serial sagittal sections with a camera lucida. Most of the STN labeled cells displayed five to eight long, sparsely spined dendrites that arborized mostly along the main axis of the nucleus. Based on their axonal targets, five distinct types of STN projection neurons have been identified: 1) neurons projecting to the substantia nigra pars reticulata (SNr), the internal (GPi) and external (GPe) segments of the globus pallidus (21.3%); 2) neurons targeting SNr and GPe (2. 7%); 3) neurons projecting to GPi and GPe (48%); 4) neurons targeting GPe only (10.7 %); and 5) neurons with axons that coursed toward the sriatum, but whose terminal arborization could not be visualized in detail (17.3%). Axons of the first two types bifurcated into rostral subthalamopallidal and caudal pallidonigral branches. However, the majority of STN axons had only a single branch that coursed rostrally toward the pallidum and striatum. These results reveal that, in contrast to current beliefs, the primate STN is not a monolithic entity. This nucleus harbors several subtypes of projection neurons, each endowed with a highly patterned set of collaterals. This organization allows STN neurons to exert a multifarious effect not only on the GPe, with which the STN is reciprocally connected, but also on the two major output structures of the basal ganglia, the SNr and the GPi.
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Affiliation(s)
- F Sato
- Laboratoire de Neurobiologie, Centre de Recherche Université Laval Robert-Giffard, Beauport, Québec G1J 2G3, Canada
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