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Lecomte CG, Mari S, Audet J, Yassine S, Merlet AN, Morency C, Harnie J, Beaulieu C, Gendron L, Frigon A. Neuromechanical Strategies for Obstacle Negotiation during Overground Locomotion following Incomplete Spinal Cord Injury in Adult Cats. J Neurosci 2023; 43:5623-5641. [PMID: 37474307 PMCID: PMC10401655 DOI: 10.1523/jneurosci.0478-23.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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: 03/16/2023] [Revised: 07/05/2023] [Accepted: 07/15/2023] [Indexed: 07/22/2023] Open
Abstract
Following incomplete spinal cord injury in animals, including humans, substantial locomotor recovery can occur. However, functional aspects of locomotion, such as negotiating obstacles, remains challenging. We collected kinematic and electromyography data in 10 adult cats (5 males, 5 females) before and at weeks 1-2 and 7-8 after a lateral mid-thoracic hemisection on the right side of the cord while they negotiated obstacles of three different heights. Intact cats always cleared obstacles without contact. At weeks 1-2 after hemisection, the ipsilesional right hindlimb contacted obstacles in ∼50% of trials, triggering a stumbling corrective reaction or absent responses, which we termed Other. When complete clearance occurred, we observed exaggerated ipsilesional hindlimb flexion when crossing the obstacle with contralesional Left limbs leading. At weeks 7-8 after hemisection, the proportion of complete clearance increased, Other responses decreased, and stumbling corrective reactions remained relatively unchanged. We found redistribution of weight support after hemisection, with reduced diagonal supports and increased homolateral supports, particularly on the left contralesional side. The main neural strategy for complete clearance in intact cats consisted of increased knee flexor activation. After hemisection, ipsilesional knee flexor activation remained, but it was insufficient or more variable as the limb approached the obstacle. Intact cats also increased their speed when stepping over an obstacle, an increase that disappeared after hemisection. The increase in complete clearance over time after hemisection paralleled the recovery of muscle activation patterns or new strategies. Our results suggest partial recovery of anticipatory control through neuroplastic changes in the locomotor control system.SIGNIFICANCE STATEMENT Most spinal cord injuries (SCIs) are incomplete and people can recover some walking functions. However, the main challenge for people with SCIs that do recover a high level of function is to produce a gait that can adjust to everyday occurrences, such as turning, stepping over an obstacle, etc. Here, we use the cat model to answer two basic questions: How does an animal negotiate an obstacle after an incomplete SCI and why does it fail to safely clear it? We show that the inability to clear an obstacle is because of improper activation of muscles that flex the knee. Animals recover a certain amount of function thanks to new strategies and changes within the nervous system.
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Affiliation(s)
- Charly G Lecomte
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Stephen Mari
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Sirine Yassine
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Angèle N Merlet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Caroline Morency
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Claudie Beaulieu
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Louis Gendron
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
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2
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Tanenbaum LN, Bash SC, Zaharchuk G, Shankaranarayanan A, Chamberlain R, Wintermark M, Beaulieu C, Novick M, Wang L. Deep Learning-Generated Synthetic MR Imaging STIR Spine Images Are Superior in Image Quality and Diagnostically Equivalent to Conventional STIR: A Multicenter, Multireader Trial. AJNR Am J Neuroradiol 2023; 44:987-993. [PMID: 37414452 PMCID: PMC10411840 DOI: 10.3174/ajnr.a7920] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 06/01/2023] [Indexed: 07/08/2023]
Abstract
BACKGROUND AND PURPOSE Deep learning image reconstruction allows faster MR imaging acquisitions while matching or exceeding the standard of care and can create synthetic images from existing data sets. This multicenter, multireader spine study evaluated the performance of synthetically created STIR compared with acquired STIR. MATERIALS AND METHODS From a multicenter, multiscanner data base of 328 clinical cases, a nonreader neuroradiologist randomly selected 110 spine MR imaging studies in 93 patients (sagittal T1, T2, and STIR) and classified them into 5 categories of disease and healthy. A DICOM-based deep learning application generated a synthetically created STIR series from the sagittal T1 and T2 images. Five radiologists (3 neuroradiologists, 1 musculoskeletal radiologist, and 1 general radiologist) rated the STIR quality and classified disease pathology (study 1, n = 80). They then assessed the presence or absence of findings typically evaluated with STIR in patients with trauma (study 2, n = 30). The readers evaluated studies with either acquired STIR or synthetically created STIR in a blinded and randomized fashion with a 1-month washout period. The interchangeability of acquired STIR and synthetically created STIR was assessed using a noninferiority threshold of 10%. RESULTS For classification, there was a decrease in interreader agreement expected by randomly introducing synthetically created STIR of 3.23%. For trauma, there was an overall increase in interreader agreement by +1.9%. The lower bound of confidence for both exceeded the noninferiority threshold, indicating interchangeability of synthetically created STIR with acquired STIR. Both the Wilcoxon signed-rank and t tests showed higher image-quality scores for synthetically created STIR over acquired STIR (P < .0001). CONCLUSIONS Synthetically created STIR spine MR images were diagnostically interchangeable with acquired STIR, while providing significantly higher image quality, suggesting routine clinical practice potential.
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Affiliation(s)
| | - S C Bash
- From RadNet (L.N.T., S.C.B.), New York, New York
| | - G Zaharchuk
- Stanford University Medical Center (G.Z., C.B.), Stanford, California
| | | | - R Chamberlain
- Subtle Medical (A.S., R.C., L.W.), Menlo Park, California
| | - M Wintermark
- MD Anderson Cancer Center (M.W.), University of Texas, Houston, Texas
| | - C Beaulieu
- Stanford University Medical Center (G.Z., C.B.), Stanford, California
| | - M Novick
- All-American Teleradiology (M.N.), Bay Village, Ohio
| | - L Wang
- Subtle Medical (A.S., R.C., L.W.), Menlo Park, California
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Audet J, Yassine S, Lecomte CG, Mari S, Soucy F, Morency C, Merlet AN, Harnie J, Beaulieu C, Gendron L, Rybak IA, Prilutsky BI, Frigon A. Spinal sensorimotor circuits play a prominent role in hindlimb locomotor recovery after staggered thoracic lateral hemisections but cannot restore posture and interlimb coordination during quadrupedal locomotion in adult cats. eNeuro 2023:ENEURO.0191-23.2023. [PMID: 37328297 DOI: 10.1523/eneuro.0191-23.2023] [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: 06/01/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/18/2023] Open
Abstract
Spinal sensorimotor circuits interact with supraspinal and peripheral inputs to generate quadrupedal locomotion. Ascending and descending spinal pathways ensure coordination between the fore- and hindlimbs. Spinal cord injury disrupts these pathways. To investigate control of interlimb coordination and hindlimb locomotor recovery, we performed two lateral thoracic hemisections on opposite sides of the cord (right T5-T6 and left T10-T11) at an interval of approximately two months in eight adult cats. In three cats, the spinal cord was transected at T12-T13. We collected electromyography and kinematic data during quadrupedal and hindlimb-only locomotion before and after spinal lesions. We show that 1) cats spontaneously recover quadrupedal locomotion following staggered hemisections but require balance assistance after the second one, 2) coordination between the fore- and hindlimbs displays 2:1 patterns (two cycles of one forelimb within one hindlimb cycle) and becomes weaker and more variable after both hemisections, 3) left-right asymmetries in hindlimb stance and swing durations appear after the first hemisection and reverse after the second, and 4) support periods reorganize after staggered hemisections to favor support involving both forelimbs and diagonal limbs. Cats expressed hindlimb locomotion the day following spinal transection, indicating that lumbar sensorimotor circuits play a prominent role in hindlimb locomotor recovery after staggered hemisections. These results reflect a series of changes in spinal sensorimotor circuits that allow cats to maintain and recover some level of quadrupedal locomotor functionality with diminished motor commands from the brain and cervical cord, although the control of posture and interlimb coordination remains impaired.Significance StatementCoordinating the limbs during locomotion depends on pathways in the spinal cord. We used a spinal cord injury model that disrupts communication between the brain and spinal cord by sectioning half of the spinal cord on one side and then about two months later, half the spinal cord on the other side at different levels of the thoracic cord in cats. We show that despite a strong contribution from neural circuits located below the second spinal cord injury in the recovery of hindlimb locomotion, the coordination between the forelimbs and hindlimbs weakens and postural control is impaired. We can use our model to test approaches to restore the control of interlimb coordination and posture during locomotion after spinal cord injury.
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Affiliation(s)
- Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Sirine Yassine
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Charly G Lecomte
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Stephen Mari
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Félix Soucy
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Caroline Morency
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Angèle N Merlet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Claudie Beaulieu
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Louis Gendron
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Ilya A Rybak
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19129, USA
| | - Boris I Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
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Audet J, Yassine S, Lecomte CG, Mari S, Félix S, Caroline M, Merlet AN, Harnie J, Beaulieu C, Gendron L, Rybak IA, Prilutsky BI, Frigon A. Spinal sensorimotor circuits play a prominent role in hindlimb locomotor recovery after staggered thoracic lateral hemisections but cannot restore posture and interlimb coordination during quadrupedal locomotion in adult cats. bioRxiv 2023:2023.03.23.533936. [PMID: 36993268 PMCID: PMC10055434 DOI: 10.1101/2023.03.23.533936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
UNLABELLED Spinal sensorimotor circuits interact with supraspinal and peripheral inputs to generate quadrupedal locomotion. Ascending and descending spinal pathways ensure coordination between the fore-and hindlimbs. Spinal cord injury disrupts these pathways. To investigate the control of interlimb coordination and hindlimb locomotor recovery, we performed two lateral thoracic hemisections placed on opposite sides of the cord (right T5-T6 and left T10-T11) at an interval of approximately two months in eight adult cats. In three cats, we then made a complete spinal transection caudal to the second hemisection at T12-T13. We collected electromyography and kinematic data during quadrupedal and hindlimb-only locomotion before and after spinal lesions. We show that 1) cats spontaneously recover quadrupedal locomotion following staggered hemisections but require balance assistance after the second one, 2) coordination between the fore-and hindlimbs displays 2:1 patterns and becomes weaker and more variable after both hemisections, 3) left-right asymmetries in hindlimb stance and swing durations appear after the first hemisection and reverse after the second, and 4) support periods reorganize after staggered hemisections to favor support involving both forelimbs and diagonal limbs. Cats expressed hindlimb locomotion the day following spinal transection, indicating that lumbar sensorimotor circuits play a prominent role in hindlimb locomotor recovery after staggered hemisections. These results reflect a series of changes in spinal sensorimotor circuits that allow cats to maintain and recover some level of quadrupedal locomotor functionality with diminished motor commands from the brain and cervical cord, although the control of posture and interlimb coordination remains impaired. SIGNIFICANCE STATEMENT Coordinating the limbs during locomotion depends on pathways in the spinal cord. We used a spinal cord injury model that disrupts communication between the brain and spinal cord by sectioning half of the spinal cord on one side and then about two months later, half the spinal cord on the other side at different levels of the thoracic cord in cats. We show that despite a strong contribution from neural circuits located below the second spinal cord injury in the recovery of hindlimb locomotion, the coordination between the forelimbs and hindlimbs weakens and postural control is impaired. We can use our model to test approaches to restore the control of interlimb coordination and posture during locomotion after spinal cord injury.
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Affiliation(s)
- Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Sirine Yassine
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Charly G Lecomte
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Stephen Mari
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Soucy Félix
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Morency Caroline
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Angèle N Merlet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Claudie Beaulieu
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Louis Gendron
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Ilya A. Rybak
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, Pennsylvania 19129, USA
| | - Boris I. Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
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5
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Lecomte CG, Mari S, Audet J, Merlet AN, Harnie J, Beaulieu C, Abdallah K, Gendron L, Rybak IA, Prilutsky BI, Frigon A. Modulation of the gait pattern during split-belt locomotion after lateral spinal cord hemisection in adult cats. J Neurophysiol 2022; 128:1593-1616. [PMID: 36382895 PMCID: PMC9744650 DOI: 10.1152/jn.00230.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 05/24/2022] [Revised: 11/10/2022] [Accepted: 11/10/2022] [Indexed: 11/17/2022] Open
Abstract
Most previous studies investigated the recovery of locomotion in animals and people with incomplete spinal cord injury (SCI) during relatively simple tasks (e.g., walking in a straight line on a horizontal surface or a treadmill). We know less about the recovery of locomotion after incomplete SCI in left-right asymmetric conditions, such as turning or stepping along circular trajectories. To investigate this, we collected kinematic and electromyography data during split-belt locomotion at different left-right speed differences before and after a right thoracic lateral spinal cord hemisection in nine adult cats. After hemisection, although cats still performed split-belt locomotion, we observed several changes in the gait pattern compared with the intact state at early (1-2 wk) and late (7-8 wk) time points. Cats with larger lesions showed new coordination patterns between the fore- and hindlimbs, with the forelimbs taking more steps. Despite this change in fore-hind coordination, cats maintained consistent phasing between the fore- and hindlimbs. Adjustments in cycle and phase (stance and swing) durations between the slow and fast sides allowed animals to maintain 1:1 left-right coordination. Periods of triple support involving the right (ipsilesional) hindlimb decreased in favor of quad support and triple support involving the other limbs. Step and stride lengths decreased with concurrent changes in the right fore- and hindlimbs, possibly to avoid interference. The above adjustments in the gait pattern allowed cats to retain the ability to locomote in asymmetric conditions after incomplete SCI. We discuss potential plastic neuromechanical mechanisms involved in locomotor recovery in these conditions.NEW & NOTEWORTHY Everyday locomotion often involves left-right asymmetries, when turning, walking along circular paths, stepping on uneven terrains, etc. To show how incomplete spinal cord injury affects locomotor control in asymmetric conditions, we collected data before and after a thoracic lateral spinal hemisection on a split-belt treadmill with one side stepping faster than the other. We show that adjustments in kinematics and muscle activity allowed cats to retain the ability to perform asymmetric locomotion after hemisection.
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Affiliation(s)
- Charly G Lecomte
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Stephen Mari
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Angèle N Merlet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Claudie Beaulieu
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Khaled Abdallah
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Louis Gendron
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Ilya A Rybak
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, Pennsylvania
| | - Boris I Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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Quirion B, Beaulieu C, Côté L, Parent JL, Gendron L. Distribution of delta and mu opioid receptor mRNA in rodent dorsal root ganglia neurons. Eur J Neurosci 2022; 56:4031-4044. [PMID: 35674691 PMCID: PMC9543299 DOI: 10.1111/ejn.15733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 05/24/2022] [Accepted: 06/02/2022] [Indexed: 12/01/2022]
Abstract
Primary afferents are responsible for transmitting signals produced by noxious stimuli from the periphery to the spinal cord. Mu and delta opioid receptors (MOP and DOP) have analgesic properties and are highly expressed in dorsal root ganglia (DRG) neurons. In humans, spinal DOP is almost exclusively located on central terminals of DRG neurons, whereas in rodents, it is expressed both on presynaptic terminals and spinal neurons. In this study, we aimed to assess the distribution of MOP and DOP in the DRGs of mice and rats. Using in situ hybridization and immunofluorescence, we visualized MOP and DOP mRNA together with various neuronal markers. In rats and mice, we show that both receptors are expressed, albeit to different extents, in all types of neurons, namely, large and medium myelinated neurons (NF200-positive), small nonpeptidergic (IB4- or P2X3R-positive) and peptidergic C fibres (Tac1-positive). Overall, DOP mRNA was found to be mainly expressed in large and medium myelinated neurons, whereas MOP mRNA was mainly found in C fibres. The distribution of MOP and DOP, however, slightly differs between rats and mice, with a higher proportion of small nonpeptidergic C fibres expressing DOP mRNA in mice than in rats. We further found that neither morphine nor inflammation affected the distribution of the receptor mRNA. Because of their location, our results confirm that MOP and DOP have the potential to alleviate similar types of pain and that this effect could slightly differ between species.
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Affiliation(s)
- Béatrice Quirion
- Département de Pharmacologie-Physiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Claudie Beaulieu
- Département de Pharmacologie-Physiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Laurie Côté
- Département de Pharmacologie-Physiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Département de Médecine, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Jean-Luc Parent
- Département de Médecine, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Louis Gendron
- Département de Pharmacologie-Physiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Quebec Pain Research Network
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Hammond ML, Beaulieu C, Henson SA, Sahu SK. Regional surface chlorophyll trends and uncertainties in the global ocean. Sci Rep 2020; 10:15273. [PMID: 32943692 PMCID: PMC7498587 DOI: 10.1038/s41598-020-72073-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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: 10/30/2019] [Accepted: 08/21/2020] [Indexed: 11/09/2022] Open
Abstract
Changes in marine primary productivity are key to determine how climate change might impact marine ecosystems and fisheries. Satellite ocean color sensors provide coverage of global ocean chlorophyll with a combined record length of ~ 20 years. Coupled physical–biogeochemical models can inform on expected changes and are used here to constrain observational trend estimates and their uncertainty. We produce estimates of ocean surface chlorophyll trends, by using Coupled Model Intercomparison Project (CMIP5) models to form priors as a “first guess”, which are then updated using satellite observations in a Bayesian spatio-temporal model. Regional chlorophyll trends are found to be significantly different from zero in 18/23 regions, in the range ± 1.8% year−1. A global average of these regional trends shows a net positive trend of 0.08 ± 0.35% year−1, highlighting the importance of considering chlorophyll changes at a regional level. We compare these results with estimates obtained with the commonly used “vague” prior, representing no independent knowledge; coupled model priors are shown to slightly reduce trend magnitude and uncertainties in most regions. The statistical model used here provides a robust framework for making best use of all available information and can be applied to improve understanding of global change.
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Affiliation(s)
- Matthew L Hammond
- National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK. .,Ocean and Earth Science, University of Southampton, Southampton, UK.
| | - Claudie Beaulieu
- Ocean and Earth Science, University of Southampton, Southampton, UK.,Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, USA
| | | | - Sujit K Sahu
- Southampton Statistical Sciences Research Institute, University of Southampton, Southampton, UK
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Beaulieu C, Kim K, Huo M, Zarit S, Fingerman K. ADULT GRANDCHILD SUPPORT PROVIDED TO GRANDPARENTS. Innov Aging 2018. [DOI: 10.1093/geroni/igy023.1062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - K Kim
- University of Massachusetts Boston
| | - M Huo
- The University of Texas at Austin
| | - S Zarit
- Pennsylvania State University
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9
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Ito YA, Smith AC, Kernohan KD, Pena IA, Ahmed A, McDonell LM, Beaulieu C, Bulman DE, Smidt A, Sawyer SL, Dyment DA, Boycott KM, Clericuzio CL. A ZPR1 mutation is associated with a novel syndrome of growth restriction, distinct craniofacial features, alopecia, and hypoplastic kidneys. Clin Genet 2018; 94:303-312. [PMID: 29851065 DOI: 10.1111/cge.13388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 03/02/2018] [Revised: 05/24/2018] [Accepted: 05/27/2018] [Indexed: 12/24/2022]
Abstract
A novel autosomal recessive disorder characterized by pre- and postnatal growth restriction with microcephaly, distinctive craniofacial features, congenital alopecia, hypoplastic kidneys with renal insufficiency, global developmental delay, severe congenital sensorineural hearing loss, early mortality, hydrocephalus, and genital hypoplasia was observed in 4 children from 3 families of New Mexican Hispanic heritage. Three of the children died before 3 years of age from uremia and/or sepsis. Exome sequencing of the surviving individual identified a homozygous c.587T>C (p.Ile196Thr) mutation in ZPR1 Zinc Finger (ZPR1) that segregated appropriately in her family. In a second family, the identical variant was shown to be heterozygous in the affected individual's parents and not homozygous in any of her unaffected siblings. ZPR1 is a ubiquitously expressed, highly conserved protein postulated to transmit proliferative signals from the cell membrane to the nucleus. Structural modeling reveals that p.Ile196Thr disrupts the hydrophobic core of ZPR1. Patient fibroblast cells showed no detectable levels of ZPR1 and the cells showed a defect in cell cycle progression where a significant number of cells remained arrested in the G1 phase. We provide genetic and molecular evidence that a homozygous missense mutation in ZPR1 is associated with a rare and recognizable multisystem syndrome.
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Affiliation(s)
- Y A Ito
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - A C Smith
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - K D Kernohan
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - I A Pena
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - A Ahmed
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - L M McDonell
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - C Beaulieu
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - D E Bulman
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - A Smidt
- Division of Genetics/Dysmorphology, Department of Pediatrics, University of New Mexico School of Medicine, Albuquerque, New Mexico.,Department of Dermatology, University of New Mexico School of Medicine, Albuquerque, New Mexico
| | - S L Sawyer
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
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- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - D A Dyment
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - K M Boycott
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - C L Clericuzio
- Division of Genetics/Dysmorphology, Department of Pediatrics, University of New Mexico School of Medicine, Albuquerque, New Mexico
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10
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Morissette B, Talbot G, Beaulieu C, Lessard M. Growth performance of piglets during the first two weeks of lactation affects the development of the intestinal microbiota. J Anim Physiol Anim Nutr (Berl) 2017; 102:525-532. [PMID: 28990221 DOI: 10.1111/jpn.12784] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [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: 03/10/2017] [Accepted: 06/18/2017] [Indexed: 01/22/2023]
Abstract
The aim of this study was to evaluate the effect of newborn piglet weight gain during the first 2 weeks of lactation on the luminal and mucosal microbiota of the ileum and colon. The microbiota from high-weight-gain (HWG) and low-weight-gain (LWG) 2-week-old piglets was characterized by amplicon length heterogeneity PCR (LH-PCR) and compared using diversity indices and multivariate statistical analyses. At birth, LWG piglets weighted in average 0.26 kg less than HWG piglets (p = .002). The weight difference between LWG and HWG piglets increased with time and reached 2.1 kg after 16 days of lactation (p < .0001). Based on these growth performance differences, estimated colostrum and milk intake was greater in HWG than in LWG piglets (p < .0001). Analysis of the LH-PCR data of the microbiota using non-metric multidimensional scaling (NMS) and blocked multiresponse permutation procedure (MRBP) revealed that the microbiota of the HWG and LWG piglets tended to differ in ileal mucosa (p = .097) and differed in colonic lumen (p = .024). The microbiota of HWG piglets had higher levels of Bacteroidetes, Bacteroides and Ruminoccocaceae, and lower proportions of Actinobacillus porcinus and Lactobacillus amylovorus when compared with those of LWG piglets. As the weight gain of nursing piglets is highly correlated with the amount of ingested colostrum and milk, the results strongly suggest that colostrum and milk intake in the first 2 weeks of life influenced the development of the gut microbiota.
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Affiliation(s)
- B Morissette
- Agriculture and Agri-Food Canada, Sherbrooke Research and Development Centre, Sherbrooke, QC, Canada.,Département de Biologie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - G Talbot
- Agriculture and Agri-Food Canada, Sherbrooke Research and Development Centre, Sherbrooke, QC, Canada
| | - C Beaulieu
- Département de Biologie, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - M Lessard
- Agriculture and Agri-Food Canada, Sherbrooke Research and Development Centre, Sherbrooke, QC, Canada
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11
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Frajka-Williams E, Beaulieu C, Duchez A. Emerging negative Atlantic Multidecadal Oscillation index in spite of warm subtropics. Sci Rep 2017; 7:11224. [PMID: 28894211 PMCID: PMC5593924 DOI: 10.1038/s41598-017-11046-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [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: 03/16/2017] [Accepted: 08/08/2017] [Indexed: 11/22/2022] Open
Abstract
Sea surface temperatures in the northern North Atlantic have shown a marked decrease over the past several years. The sea surface in the subpolar gyre is now as cold as it was during the last cold phase of the Atlantic Multidecadal Oscillation index in the 1990s. This climate index is associated with shifts in hurricane activity, rainfall patterns and intensity, and changes in fish populations. However, unlike the last cold period in the Atlantic, the spatial pattern of sea surface temperature anomalies in the Atlantic is not uniformly cool, but instead has anomalously cold temperatures in the subpolar gyre, warm temperatures in the subtropics and cool anomalies over the tropics. The tripole pattern of anomalies has increased the subpolar to subtropical meridional gradient in SSTs, which are not represented by the AMO index value, but which may lead to increased atmospheric baroclinicity and storminess. Here we show that the recent Atlantic cooling is likely to persist, as predicted by a statistical forecast of subsurface ocean temperatures and consistent with the irreversible nature of watermass changes involved in the recent cooling of the subpolar gyre.
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Affiliation(s)
| | - Claudie Beaulieu
- University of Southampton, Ocean and Earth Science, Southampton, SO14 3ZH, United Kingdom
| | - Aurelie Duchez
- National Oceanography Centre Southampton, Southampton, SO14 3ZH, United Kingdom
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12
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Henson SA, Beaulieu C, Lampitt R. Observing climate change trends in ocean biogeochemistry: when and where. Glob Chang Biol 2016; 22:1561-71. [PMID: 26742651 PMCID: PMC4785610 DOI: 10.1111/gcb.13152] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 10/12/2015] [Accepted: 10/19/2015] [Indexed: 05/21/2023]
Abstract
Understanding the influence of anthropogenic forcing on the marine biosphere is a high priority. Climate change-driven trends need to be accurately assessed and detected in a timely manner. As part of the effort towards detection of long-term trends, a network of ocean observatories and time series stations provide high quality data for a number of key parameters, such as pH, oxygen concentration or primary production (PP). Here, we use an ensemble of global coupled climate models to assess the temporal and spatial scales over which observations of eight biogeochemically relevant variables must be made to robustly detect a long-term trend. We find that, as a global average, continuous time series are required for between 14 (pH) and 32 (PP) years to distinguish a climate change trend from natural variability. Regional differences are extensive, with low latitudes and the Arctic generally needing shorter time series (<~30 years) to detect trends than other areas. In addition, we quantify the 'footprint' of existing and planned time series stations, that is the area over which a station is representative of a broader region. Footprints are generally largest for pH and sea surface temperature, but nevertheless the existing network of observatories only represents 9-15% of the global ocean surface. Our results present a quantitative framework for assessing the adequacy of current and future ocean observing networks for detection and monitoring of climate change-driven responses in the marine ecosystem.
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Affiliation(s)
| | - Claudie Beaulieu
- Ocean and Earth SciencesUniversity of SouthamptonEuropean WaySouthamptonSO14 3ZHUK
| | - Richard Lampitt
- National Oceanography CentreEuropean WaySouthamptonSO14 3ZHUK
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13
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McLachlan K, Vavasour I, MacKay A, Reynolds J, Oberlander T, Loock C, Beaulieu C. ISDN2014_0381: Brain myelin water imaging of children with prenatal alcohol exposure: Findings from the NeuroDevNet FASD Study. Int J Dev Neurosci 2015. [DOI: 10.1016/j.ijdevneu.2015.04.301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Affiliation(s)
- K. McLachlan
- University of AlbertaCanada
- University of British ColumbiaCanada
| | | | - A. MacKay
- University of British ColumbiaCanada
| | | | | | - C. Loock
- University of British ColumbiaCanada
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14
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Fall ML, Van der Heyden H, Beaulieu C, Carisse O. Bremia lactucae Infection Efficiency in Lettuce is Modulated by Temperature and Leaf Wetness Duration Under Quebec Field Conditions. Plant Dis 2015; 99:1010-1019. [PMID: 30690977 DOI: 10.1094/pdis-05-14-0548-re] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
More than 80% of Canadian lettuce production is located in the province of Quebec. Yet most of our knowledge on the epidemiology of lettuce downy mildew (Bremia lactucae) is derived from controlled-condition experiments or field experiments conducted in subtropical climates and, thus, cannot readily be applied to Quebec lettuce production. The influence of temperature and leaf wetness duration on the infection efficiency (IE) of B. lactucae was studied for 4 years (2003, 2004, 2012, and 2013) under field and growth-chamber conditions. IE was defined as the ratio of the number of lesions/leaf to the airborne conidia concentration (ACC). B. lactucae ACC was measured with rotating-arm samplers three times/week. In addition, 72 lettuce trap plants/sampling day were exposed to the potential airborne B. lactucae inoculum and disease intensity was assessed after 7 days of incubation in greenhouse. Under growth-chamber conditions, an ACC of 1 conidium/m3 was sufficient to cause 1 lesion/leaf, and IE ranged from 0.25 to 1.00. Under field conditions, an ACC of 10 to 14 conidia/m3 was required to cause 1 lesion/leaf, and IE ranged from 0.02 to 0.10, except in 2004, when IE ranged from 0.03 to 1.00. IE increased with increasing leaf wetness duration but decreased with increasing temperature. Also, considering an observed average temperature range from 10 to 20°C in the area of Quebec, 2 h of leaf wetness was sufficient for infection by B. lactucae. Therefore, under Quebec lettuce production conditions, a leaf wetness period of 2 h and an ACC of 10 to 14 conidia/m3 can be used as risk indicators to facilitate disease management decisions. Also, under typical Quebec weather conditions, measuring both morning and evening leaf wetness events could be used to improve the reliability of leaf wetness duration as a downy mildew risk indicator. Further research is needed to validate these risk indicators for integration into management strategies.
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Affiliation(s)
- M L Fall
- Biology Department, University of Sherbrooke, Sherbrooke, QC, Canada J1K 2R1 and Horticulture Research and Development Centre, Agriculture and Agri-Food Canada, St-Jean-sur-Richelieu, QC, Canada J3B 3E6
| | - H Van der Heyden
- Compagnie de Recherche Phytodata Inc., Sherrington, QC, Canada J0L 2N0
| | - C Beaulieu
- Biology Department, University of Sherbrooke
| | - O Carisse
- Horticulture Research and Development Centre, Agriculture and Agri-Food Canada
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15
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Chardon JW, Smith A, Woulfe J, Pena E, Rakhra K, Dennie C, Beaulieu C, Huang L, Schwartzentruber J, Hawkins C, Harms M, Dojeiji S, Zhang M, Majewski J, Bulman D, Boycott K, Dyment D. LIMS2 mutations are associated with a novel muscular dystrophy, severe cardiomyopathy and triangular tongues. Clin Genet 2015; 88:558-64. [DOI: 10.1111/cge.12561] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 01/07/2015] [Accepted: 01/09/2015] [Indexed: 02/03/2023]
Affiliation(s)
- Jodi Warman Chardon
- Department of Genetics; Children's Hospital of Eastern Ontario; Ottawa Ontario Canada
- Ottawa Hospital Research Institute; Ottawa Ontario Canada
| | - A.C. Smith
- Children's Hospital of Eastern Ontario Research Institute; University of Ottawa; Ottawa Ontario Canada
| | - J. Woulfe
- Department of Pathology; The Ottawa Hospital; Ottawa Ontario Canada
- Ottawa Hospital Research Institute; Ottawa Ontario Canada
| | - E. Pena
- Department of Medical Imaging; The Ottawa Hospital; Ottawa Ontario Canada
| | - K. Rakhra
- Ottawa Hospital Research Institute; Ottawa Ontario Canada
- Department of Medical Imaging; The Ottawa Hospital; Ottawa Ontario Canada
| | - C. Dennie
- Ottawa Hospital Research Institute; Ottawa Ontario Canada
- Department of Medical Imaging; The Ottawa Hospital; Ottawa Ontario Canada
- University of Ottawa Heart Institute; Ottawa Ontario Canada
| | - C. Beaulieu
- Children's Hospital of Eastern Ontario Research Institute; University of Ottawa; Ottawa Ontario Canada
| | - Lijia Huang
- Children's Hospital of Eastern Ontario Research Institute; University of Ottawa; Ottawa Ontario Canada
| | - J. Schwartzentruber
- McGill University and Genome Quebec Innovation Center; Montreal Quebec Canada
| | - C. Hawkins
- Department of Laboratory Medicine & Pathobiology; The Hospital for Sick Children; Toronto Ontario Canada
| | - M.B. Harms
- Department of Neurology and Hope Center for Neurological Disorders; Washington University; Saint Louis MO USA
| | - S. Dojeiji
- The Ottawa Hospital Rehabilitation Center; Ottawa Ontario Canada
| | - M. Zhang
- Ottawa Hospital Research Institute; Ottawa Ontario Canada
| | - J. Majewski
- Department of Human Genetics; McGill University; Montreal Quebec Canada
| | - D.E. Bulman
- Children's Hospital of Eastern Ontario Research Institute; University of Ottawa; Ottawa Ontario Canada
- Department of Pediatrics; Children's Hospital of Eastern Ontario; Ottawa Ontario Canada
| | - K.M. Boycott
- Department of Genetics; Children's Hospital of Eastern Ontario; Ottawa Ontario Canada
- Children's Hospital of Eastern Ontario Research Institute; University of Ottawa; Ottawa Ontario Canada
| | - D.A. Dyment
- Department of Genetics; Children's Hospital of Eastern Ontario; Ottawa Ontario Canada
- Children's Hospital of Eastern Ontario Research Institute; University of Ottawa; Ottawa Ontario Canada
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16
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Beaulieu C, Dionne LL, Julien AS, Longtin Y. Clinical characteristics and outcome of patients with Clostridium difficile infection diagnosed by PCR versus a three-step algorithm. Clin Microbiol Infect 2014; 20:1067-73. [PMID: 24813402 DOI: 10.1111/1469-0691.12676] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 04/19/2014] [Accepted: 05/05/2014] [Indexed: 02/04/2023]
Abstract
Clinical features of Clostridium difficile infections (CDI) detected by PCR, but not by conventional methods, are poorly understood. We compared the clinical features of CDI cases detected by PCR only and cases detected by both PCR and a three-step algorithm. We performed a retrospective cohort study of patients fulfilling a standardized definition over a 13-month period. Stool specimens were tested in parallel by PCR and an algorithm based on enzyme immunoassay and cytotoxicity assay (EIA/CCA). Clinical features of CDI cases detected by PCR only and cases detected by PCR and EIA/CCA were compared by univariate logistic regression. In all, 97 patients (31 PCR+ and 66 PCR+EIA/CCA+) met the inclusion criteria. Compared with cases detected by both PCR and EIA/CCA, CDI cases detected by PCR only were younger (65.4 versus 76.3 years; p 0.001), had a lower absolute neutrophil count (mean, 9.4 × 10(9) /L versus 12.5 × 10(9) /L; p 0.04), were less likely to receive oral vancomycin (2/31 versus 25/66; p 0.005) or combination therapy (0/31 versus 16/66; p 0.04), and had fewer complications (6/31 versus 29/66; p 0.02), despite presenting a higher number of bowel movements on the day of diagnosis (median, 6.0 versus 3.0; p 0.02). They had also a lower C. difficile faecal bacterial load (mean, 5.04 versus 6.89 log10 CFU/g; p <0.001). The CDI cases detected by PCR only and cases detected by both PCR and EIA/CCA have different clinical features, but whether these two populations can be managed differently remains to be determined.
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Affiliation(s)
- C Beaulieu
- Laval University Faculty of Medicine, Quebec City, QC, Canada; Infectious Diseases Research Centre, Centre Hospitalier Universitaire de Québec, Quebec City, QC, Canada
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17
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Treit S, Chen Z, Rasmussen C, Beaulieu C. White matter correlates of cognitive inhibition during development: a diffusion tensor imaging study. Neuroscience 2013; 276:87-97. [PMID: 24355493 DOI: 10.1016/j.neuroscience.2013.12.019] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 12/06/2013] [Accepted: 12/09/2013] [Indexed: 11/24/2022]
Abstract
Inhibitory control and cognitive flexibility are two key executive functions that develop in childhood and adolescence, increasing one's capacity to respond dynamically to changing external demands and refrain from impulsive behaviors. These gains evolve in concert with significant brain development. Magnetic resonance imaging studies have identified numerous frontal and cingulate cortical areas associated with performance on inhibition tasks, but less is known about the involvement of the underlying anatomical connectivity, namely white matter. Here we used diffusion tensor imaging (DTI) to examine correlations between a DTI-derived parameter, fractional anisotropy (FA) of white matter, and performance on the NEPSY-II Inhibition test (Naming, Inhibition and Switching conditions) in 49 healthy children aged 5-16years (20 females; 29 males). First, whole brain voxel-based analysis revealed several clusters in the frontal projections of the corpus callosum, where higher FA was associated with worse inhibitory performance, as well as several clusters in posterior brain regions and one in the brainstem where higher FA was associated with better cognitive flexibility (in the Switching task), suggesting a dichotomous relationship between FA and these two aspects of cognitive control. Tractography through these clusters identified several white matter tracts, which were then manual traced in native space. Pearson's correlations confirmed associations between higher FA of frontal projections of the corpus callosum with poorer inhibitory performance (independent of age), though associations with Switching were not significant. Post-hoc evaluation suggested that FA of orbital and anterior frontal projections of the corpus callosum also mediated performance differences across conditions, which may reflect differences in self-monitoring or strategy use. These findings suggest a link between the development of inhibition and cognitive control with that of the underlying white matter, and may help to identify deviations of neurobiology in adolescent psychopathology.
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Affiliation(s)
- S Treit
- Centre for Neuroscience, University of Alberta, Edmonton, AB T6G-2V2, Canada
| | - Z Chen
- Department of Biomedical Engineering, University of Alberta, Edmonton, AB T6G-2V2, Canada
| | - C Rasmussen
- Centre for Neuroscience, University of Alberta, Edmonton, AB T6G-2V2, Canada; Department of Pediatrics, University of Alberta, Edmonton, AB T6G-2V2, Canada
| | - C Beaulieu
- Centre for Neuroscience, University of Alberta, Edmonton, AB T6G-2V2, Canada; Department of Biomedical Engineering, University of Alberta, Edmonton, AB T6G-2V2, Canada.
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18
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Krähenbühl JD, Beaulieu C, Gehri M. Evaluation of a novel in-vitro diagnostic device for the detection of urinary tract infections in diaper wearing children. Swiss Med Wkly 2012; 142:w13560. [DOI: 10.4414/smw.2012.13560] [Citation(s) in RCA: 2] [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: 11/18/2022] Open
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19
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Beaulieu C, Chen J, Sarmiento JL. Change-point analysis as a tool to detect abrupt climate variations. Philos Trans A Math Phys Eng Sci 2012; 370:1228-1249. [PMID: 22291231 DOI: 10.1098/rsta.2011.0383] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Recently, there have been an increasing number of studies using change-point methods to detect artificial or natural discontinuities and regime shifts in climate. However, a major drawback with most of the currently used change-point methods is the lack of flexibility (able to detect one specific type of shift under the assumption that the residuals are independent). As temporal variations in climate are complex, it may be difficult to identify change points with very simple models. Moreover, climate time series are known to exhibit autocorrelation, which corresponds to a model misspecification if not taken into account and can lead to the detection of non-existent shifts. In this study, we extend a method known as the informational approach for change-point detection to take into account the presence of autocorrelation in the model. The usefulness and flexibility of this approach are demonstrated through applications. Furthermore, it is highly desirable to develop techniques that can detect shifts soon after they occur for climate monitoring. To address this, we also carried out a simulation study in order to investigate the number of years after which an abrupt shift is detectable. We use two decision rules in order to decide whether a shift is detected or not, which represents a trade-off between increasing our chances of detecting a shift and reducing the risk of detecting a shift while in reality there is none. We show that, as of now, we have good chances to detect an abrupt shift with a magnitude that is larger than that of the standard deviation in the series of observations. For shifts with a very large magnitude (three times the standard deviation), our simulation study shows that after only 4 years the probabilities of shift detection reach nearly 100 per cent. This reveals that the approach has potential for climate monitoring.
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Affiliation(s)
- Claudie Beaulieu
- Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ 08540, USA.
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20
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Baron CA, Lebel RM, Wilman AH, Beaulieu C. The effect of concomitant gradient fields on diffusion tensor imaging. Magn Reson Med 2012; 68:1190-201. [PMID: 22851517 DOI: 10.1002/mrm.24120] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 11/01/2011] [Accepted: 11/28/2011] [Indexed: 12/21/2022]
Abstract
Concomitant gradient fields are transverse magnetic field components that are necessarily present to satisfy Maxwell's equations when magnetic field gradients are utilized in magnetic resonance imaging. They can have deleterious effects that are more prominent at lower static fields and/or higher gradient strengths. In diffusion tensor imaging schemes that employ large gradients that are not symmetric about a refocusing radiofrequency pulse (unlike Stejskal-Tanner, which is symmetric), concomitant fields may cause phase accrual that could corrupt the diffusion measurement. Theory predicting the error from this dephasing is described and experimentally validated for both Reese twice-refocused and split gradient single spin-echo diffusion gradient schemes. Bias in apparent diffusion coefficient values was experimentally found to worsen with distance from isocenter and with increasing duration of gradient asymmetry in both a phantom and in the brain. The amount of error from concomitant gradient fields depends on many variables, including the diffusion gradient pattern, pulse sequence timing, maximum effective gradient amplitude, static magnetic field strength, voxel size, slice distance from isocenter, and partial Fourier fraction. A prospective correction scheme that can reduce concomitant gradient errors is proposed and verified for diffusion imaging.
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Affiliation(s)
- C A Baron
- Department of Biomedical Engineering, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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21
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Lebel C, Gee M, Camicioli R, Wieler M, Martin W, Beaulieu C. Diffusion tensor imaging of white matter tract evolution over the lifespan. Neuroimage 2011; 60:340-52. [PMID: 22178809 DOI: 10.1016/j.neuroimage.2011.11.094] [Citation(s) in RCA: 774] [Impact Index Per Article: 59.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 10/31/2011] [Accepted: 11/30/2011] [Indexed: 01/12/2023] Open
Abstract
Diffusion tensor imaging (DTI) has been used widely to show structural brain changes during both development and aging. Lifespan studies are valuable because they connect these two processes, yet few DTI studies have been conducted that include both children and elderly subjects. This study used DTI tractography to investigate 12 major white matter connections in 403 healthy subjects aged 5-83 years. Poisson fits were used to model changes of fractional anisotropy (FA) and mean diffusivity (MD) across the age span, and were highly significant for all tracts. FA increased during childhood and adolescence, reached a peak between 20 and 42 years of age, and then decreased. MD showed an opposite trend, decreasing first, reaching a minimum at 18-41 years, and then increasing later in life. These trajectories demonstrate rates and timing of development and degradation that vary regionally in the brain. The corpus callosum and fornix showed early reversals of development trends, while frontal-temporal connections (cingulum, uncinate, superior longitudinal) showed more prolonged maturation and delayed declines. FA changes were driven by perpendicular diffusivity, suggesting changes of myelination and/or axonal density. Tract volume changed significantly with age for most tracts, but did not greatly influence the FA and MD trajectories. This study demonstrates clear age-related microstructural changes throughout the brain white matter, and provides normative data that will be useful for studying white matter development in a variety of diseases and abnormal conditions.
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Affiliation(s)
- C Lebel
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
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22
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Fallows R, McCoy K, Hertza J, Klosson E, Estes B, Stroescu I, Salinas C, Stringer A, Aronson S, MacAllister W, Spurgin A, Morriss M, Glasier P, Stavinoha P, Houshyarnejad A, Jacobus J, Norman M, Peery S, Mattingly M, Pennuto T, Anderson-Hanley C, Miele A, Dunnam M, Edwards M, O'Bryant S, Johnson L, Barber R, Inscore A, Kegel J, Kozlovsky A, Tarantino B, Goldberg A, Herrera-Pino J, Jubiz-Bassi N, Rashid K, Noniyeva Y, Vo K, Stephens V, Gomez R, Sanders C, Kovacs M, Walton B, Schmitter-Edgecombe M, Schmitter-Edgecombe M, Parsey C, Cook D, Woods S, Weinborn M, Velnoweth A, Rooney A, Bucks R, Adalio C, White S, Blair J, Barber B, Marcy S, Barber B, Marcy S, Boseck J, McCormick C, Davis A, Berry K, Koehn E, Tiberi N, Gelder B, Brooks B, Sherman E, Garcia M, Robillard R, Gunner J, Miele A, Lynch J, McCaffrey R, Hamilton J, Froming K, Nemeth D, Steger A, Lebby P, Harrison J, Mounoutoua A, Preiss J, Brimager A, Gates E, Chang J, Cisneros H, Long J, Petrauskas V, Casey J, Picard E, Long J, Petrauskas V, Casey J, Picard E, Miele A, Gunner J, Lynch J, McCaffrey R, Rodriguez M, Fonseca F, Golden C, Davis J, Wall J, DeRight J, Jorgensen R, Lewandowski L, Ortigue S, Etherton J, Axelrod B, Green C, Snead H, Semrud-Clikeman M, Kirk J, Connery A, Kirkwood M, Hanson ML, Fazio R, Denney R, Myers W, McGuire A, Tree H, Waldron-Perrine B, Goldenring Fine J, Spencer R, Pangilinan P, Bieliauskas L, Na S, Waldron-Perrine B, Tree H, Spencer R, Pangilinan P, Bieliauskas L, Peck C, Bledsoe J, Schroeder R, Boatwright B, Heinrichs R, Baade L, Rohling M, Hill B, Ploetz D, Womble M, Shenesey J, Schroeder R, Semrud-Clikeman M, Baade L, VonDran E, Webster B, Brockman C, Burgess A, Heinrichs R, Schroeder R, Baade L, VonDran E, Webster B, Goldenring Fine J, Brockman C, Heinrichs R, Schroeder R, Baade L, VonDran E, Webster B, Brockman C, Heinrichs R, Schroeder R, Baade L, Bledsoe J, VonDran E, Webster B, Brockman C, Heinrichs R, Schroeder R, Baade L, VonDran E, Webster B, Brockman C, Heinrichs R, Thaler N, Strauss G, White T, Gold J, Tree H, Waldron-Perrine B, Spencer R, McGuire A, Na S, Pangilinan P, Bieliauskas L, Allen D, Vincent A, Roebuck-Spencer T, Cooper D, Bowles A, Gilliland K, Watts A, Ahmed F, Miller L, Yon A, Gordon B, Bello D, Bennett T, Yon A, Gordon B, Bennett T, Wood N, Etcoff L, Thede L, Oraker J, Gibson F, Stanford L, Gray S, Vroman L, Semrud-Clikeman M, Taylor T, Seydel K, Bure-Reyes A, Stewart J, Tourgeman I, Demsky Y, Golden C, Burns W, Gray S, Burns K, Calderon C, Tourgeman I, Golden C, Neblina C, San Miguel Montes L, Allen D, Strutt A, Scott B, Strutt A, Scott B, Armstrong P, Booth C, Blackstone K, Moore D, Gouaux B, Ellis R, Atkinson J, Grant I, Brennan L, Schultheis M, Hurtig H, Weintraub D, Duda J, Moberg P, Chute D, Siderowf A, Brescian N, Gass C, Brewster R, King T, Morris R, Krawiecki N, Dinishak D, Richardson G, Estes B, Knight M, Hertza J, Fallows R, McCoy K, Garcia S, Strain G, Devlin M, Cohen R, Paul R, Crosby R, Mitchell J, Gunstad J, Hancock L, Bruce J, Roberg B, Lynch S, Hertza J, Klosson E, Varnadore E, Schiff W, Estes B, Hertza J, Varnadore E, Estes B, Kaufman R, Rinehardt E, Schoenberg M, Mattingly M, Rosado Y, Velamuri S, LeBlanc M, Pimental P, Lynch-Chee S, Broshek D, Lyons P, McKeever J, Morse C, Ang J, Leist T, Tracy J, Schultheis M, Morgan E, Woods S, Rooney A, Perry W, Grant I, Letendre S, Morse C, McKeever J, Schultheis M, Musso M, Jones G, Hill B, Proto D, Barker A, Gouvier W, Nersesova K, Drexler M, Cherkasova E, Sakamoto M, Marcotte T, Hilsabeck R, Perry W, Carlson M, Barakat F, Hassanein T, Shevchik K, McCaw W, Schrock B, Smith M, Moser D, Mills J, Epping E, Paulsen J, Somogie M, Bruce J, Bryan F, Buscher L, Tyrer J, Stabler A, Thelen J, Lovelace C, Spurgin A, Graves D, Greenberg B, Harder L, Szczebak M, Glisky M, Thelen J, Lynch S, Hancock L, Bruce J, Ukueberuwa D, Arnett P, Vahter L, Ennok M, Pall K, Gross-Paju K, Vargas G, Medaglia J, Chiaravalloti N, Zakrzewski C, Hillary F, Andrews A, Golden C, Belloni K, Nicewander J, Miller D, Johnson S, David Z, Weideman E, Lawson D, Currier E, Morton J, Robinson J, Musso M, Hill B, Barker A, Pella R, Jones G, Proto D, Gouvier W, Vertinski M, Allen D, Thaler N, Heisler D, Park B, Barney S, Kucukboyaci N, Girard H, Kemmotsu N, Cheng C, Kuperman J, McDonald C, Carroll C, Odland A, Miller L, Mittenberg W, Coalson D, Wahlstrom D, Raiford S, Holdnack J, Ennok M, Vahter L, Gardner E, Dasher N, Fowler B, Vik P, Grajewski M, Lamar M, Penney D, Davis R, Korthauer L, Libon D, Kumar A, Holdnack J, Iverson G, Chelune G, Hunter C, Zimmerman E, Klein R, Prathiba N, Hopewell A, Cooper D, Kennedy J, Long M, Moses J, Lutz J, Tiberi N, Dean R, Miller J, Axelrod B, Van Dyke S, Rapport L, Schutte C, Hanks R, Pella R, Fallows R, McCoy K, O'Rourke J, Hilsabeck R, Petrauskas V, Bowden S, Romero R, Hulkonen R, Boivin M, Bangirana P, John C, Shapiro E, Slonaker A, Pass L, Smigielski J, Biernacka J, Geske J, Hall-Flavin D, Loukianova L, Schneekloth T, Abulseoud O, Mrazek D, Karpyak V, Terranova J, Safko E, Heisler D, Thaler N, Allen D, Van Dyke S, Axelrod B, Zink D, Puente A, Ames H, LePage J, Carroll C, Knee K, Mittenberg W, Cummings T, Webbe F, Shepherd E, Marcinak J, Diaz-Santos M, Seichepine D, Sullivan K, Neargarder S, Cronin-Golomb A, Franchow E, Suchy Y, Kraybill M, Holland A, Newton S, Hinson D, Smith A, Coe M, Carmona J, Harrison D, Hyer L, Atkinson M, Dalibwala J, Yeager C, Hyer L, Scott C, Atkinson M, Yeager C, Jacobson K, Olson K, Pella R, Fallows R, McCoy K, O'Rourke J, Hilsabeck R, Rosado Y, Kaufman R, Velamuri S, Rinehardt E, Mattingly M, Sartori A, Clay O, Ovalle F, Rothman R, Crowe M, Schmid A, Horne L, Horn G, Johnson-Markve B, Gorman P, Stewart J, Bure-Reyes A, Golden C, Tam J, McAlister C, Schmitter-Edgecombe M, Wagner M, Brenner L, Walker A, Armstrong L, Inman E, Grimmett J, Gray S, Cornelius A, Hertza J, Klosson E, Varnadore E, Schiff W, Estes B, Johnson L, Willingham M, Restrepo L, Bolanos J, Patel F, Golden C, Rice J, Dougherty M, Golden C, Sharma V, Martin P, Golden C, Bradley E, Dinishak D, Lockwood C, Poole J, Brickell T, Lange R, French L, Chao L, Klein S, Dunnam M, Miele A, Warner G, Donnelly K, Donnelly J, Kittleson J, Bradshaw C, Alt M, England D, Denney R, Meyers J, Evans J, Lynch-Chee S, Kennedy C, Moore J, Fedor A, Spitznagel M, Gunstad J, Ferland M, Guerrero NK, Davidson P, Collins B, Marshall S, Herrera-Pino J, Samper G, Ibarra S, Parrott D, Steffen F, Backhaus S, Karver C, Wade S, Taylor H, Brown T, Kirkwood M, Stancin T, Krishnan K, Culver C, Arenivas A, Bosworth C, Shokri-Kojori E, Diaz-Arrastia R, Marquez de la PC, Lange R, Ivins B, Marshall K, Schwab K, Parkinson G, Iverson G, Bhagwat A, French L, Lichtenstein J, Adams-Deutsch Z, Fleischer J, Goldberg K, Lichtenstein J, Adams-Deutsch Z, Fleischer J, Goldberg K, Lichtenstein J, Fleischer J, Goldberg K, Lockwood C, Ehrler M, Hull A, Bradley E, Sullivan C, Poole J, Lockwood C, Sullivan C, Hull A, Bradley E, Ehrler M, Poole J, Marcinak J, Schuster D, Al-Khalil K, Webbe F, Myers A, Ireland S, Simco E, Carroll C, Mittenberg W, Palmer E, Poole J, Bradley E, Dinishak D, Piecora K, Marcinak J, Al-Khalil K, Mroczek N, Schuster D, Snyder A, Rabinowitz A, Arnett P, Schatz P, Cameron N, Stolberg P, Hart J, Jones W, Mayfield J, Allen D, Sullivan K, Edmed S, Vanderploeg R, Silva M, Vaughan C, McGuire E, Gerst E, Fricke S, VanMeter J, Newman J, Gioia G, Vaughan C, VanMeter J, McGuire E, Gioia G, Newman J, Gerst E, Fricke S, Wahlberg A, Zelonis S, Chatterjee A, Smith S, Whipple E, Mace L, Manning K, Ang J, Schultheis M, Wilk J, Herrell R, Hoge C, Zakzanis K, Yu S, Jeffay E, Zimmer A, Webbe F, Piecora K, Schuster D, Zimmer A, Piecora K, Schuster D, Webbe F, Adler M, Holster J, Golden C, Andrews A, Schleicher-Dilks S, Golden C, Arffa S, Thornton J, Arffa S, Thornton J, Arffa S, Thornton J, Arffa S, Thornton J, Canas A, Sevadjian C, Fournier A, Miller D, Maricle D, Donders J, Larsen T, Gidley Larson J, Sheehan J, Suchy Y, Higgins K, Rolin S, Dunham K, Akeson S, Horton A, Reynolds C, Horton A, Reynolds C, Jordan L, Gonzalez S, Heaton S, McAlister C, Tam J, Schmitter-Edgecombe M, Olivier T, West S, Golden C, Prinzi L, Martin P, Robbins J, Bruzinski B, Golden C, Riccio C, Blakely A, Yoon M, Reynolds C, Robbins J, Prinzi L, Martin P, Golden C, Schleicher-Dilks S, Andrews A, Adler M, Pearlson J, Golden C, Sevadjian C, Canas A, Fournier A, Miller D, Maricle D, Sheehan J, Gidley LJ, Suchy Y, Sherman E, Carlson H, Gaxiola-Valdez I, Wei X, Beaulieu C, Hader W, Brooks B, Kirton A, Barlow K, Hrabok M, Mohamed I, Wiebe S, Smith K, Ailion A, Ivanisevic M, King T, Smith K, King T, Thorgusen S, Bowman D, Suchy Y, Walsh K, Mitchell F, Jill G, Iris P, Ross K, Madan-Swain A, Gioia G, Isquith P, Webber D, DeFilippis N, Collins M, Hill F, Weber R, Johnson A, Wiley C, Zimmerman E, Burns T, DeFilippis N, Ritchie D, Odland A, Stevens A, Mittenberg W, Hartlage L, Williams B, Weidemann E, Demakis G, Avila J, Razani J, Burkhart S, Adams W, Edwards M, O'Bryant S, Hall J, Johnson L, Grammas P, Gong G, Hargrave K, Mattevada S, Barber R, Hall J, Vo H, Johnson L, Barber R, O'Bryant S, Hill B, Davis J, O'Connor K, Musso M, Rehm-Hamilton T, Ploetz D, Rohling M, Rodriguez M, Potter E, Loewenstein D, Duara R, Golden C, Velamuri S, Rinehardt E, Schoenberg M, Mattingly M, Kaufman R, Rosado Y, Boseck J, Tiberi N, McCormick C, Davis A, Hernandez Finch M, Gelder B, Cannon M, McGregor S, Reitman D, Rey J, Scarisbrick D, Holdnack J, Iverson G, Thaler N, Bello D, Whoolery H, Etcoff L, Vekaria P, Whittington L, Nemeth D, Gremillion A, Olivier T, Amirthavasagam S, Jeffay E, Zakzanis K, Barney S, Umuhoza D, Strauss G, Knatz-Bello D, Allen D, Bolanos J, Bell J, Restrepo L, Frisch D, Golden C, Hartlage L, Williams B, Iverson G, McIntosh D, Kjernisted K, Young A, Kiely T, Tai C, Gomez R, Schatzberg A, Keller J, Rhodes E, Ajilore O, Zhang A, Kumar A, Lamar M, Ringdahl E, Sutton G, Turner A, Snyder J, Allen D, Verbiest R, Thaler N, Strauss G, Allen D, Walkenhorst E, Crowe S, August-Fedio A, Sexton J, Cummings S, Brown K, Fedio P, Grigorovich A, Fish J, Gomez M, Leach L, Lloyd H, Nichols M, Goldberg M, Novakovic-Agopian T, Chen A, Abrams G, Rossi A, Binder D, Muir J, Carlin G, Murphy M, McKim R, Fitsimmons R, D'Esposito M, Shevchik K, McCaw W, Schrock B, Vernon A, Frank R, Ona PZ, Freitag E, Weber E, Woods S, Kellogg E, Grant I, Basso M, Dyer B, Daniel M, Michael P, Fontanetta R, Martin P, Golden C, Gass C, Stripling A, Odland A, Holster J, Corsun-Ascher C, Olivier T, Golden C, Legaretta M, Vik P, Van Ness E, Fowler B, Noll K, Denney D, Wiechman A, Stephanie T, Greenberg B, Lacritz L, Padua M, Sandhu K, Moses J, Sordahl J, Anderson J, Wheaton V, Anderson J, Berggren K, Cheung D, Luber H, Loftis J, Huckans M, Bennett T, Dawson C, Soper H, Bennett T, Soper H, Carter K, Hester A, Ringe W, Spence J, Posamentier M, Hart J, Haley R, Fallows R, Pella R, McCoy K, O'Rourke J, Hilsabeck R, Fallows R, Pella R, McCoy K, O'Rourke J, Hilsabeck R, Gass C, Curiel R, Gass C, Stripling A, Odland A, Goldberg M, Lloyd H, Gremillion A, Nemeth D, Whittington L, Hu E, Vik P, Dasher N, Fowler B, Jeffay E, Zakzanis K, Jordan S, DeFilippis N, Collins M, Goetsch V, Small S, Mansoor Y, Homer-Smith E, Lockwood C, Moses J, Martin P, Odland A, Fontanetta R, Sharma V, Golden C, Odland A, Martin P, Perle J, Gass C, Simco E, Mittenberg W, Patt V, Minassian A, Perry W, Polott S, Webbe F, Mulligan K, Shaneyfelt K, Wall J, Thompson J, Tai C, Kiely T, Compono V, Trettin L, Gomez R, Schatzberg A, Keller J, Tsou J, Pearlson J, Sharma V, Tourgeman I, Golden C, Waldron-Perrine B, Tree H, Spencer R, McGuire A, Na S, Pangilinan P, Bieliauskas L, You S, Moses J, An K, Jeffay E, Zakzanis K, Biddle C, Fazio R, Willett K, Rolin S, O'Grady M, Denney R, Bresnan K, Erlanger D, Seegmiller R, Kaushik T, Brooks B, Krol A, Carlson H, Sherman E, Davis J, McHugh T, Axelrod B, Hanks R. Grand Rounds. Arch Clin Neuropsychol 2011. [DOI: 10.1093/arclin/acr056] [Citation(s) in RCA: 3] [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: 11/13/2022] Open
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Clermont N, Lerat S, Beaulieu C. Genome shuffling enhances biocontrol abilities of Streptomyces strains against two potato pathogens. J Appl Microbiol 2011; 111:671-82. [DOI: 10.1111/j.1365-2672.2011.05078.x] [Citation(s) in RCA: 17] [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: 11/29/2022]
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Baz M, Lahbabi D, Samri S, Val F, Hamelin G, Madore I, Bouarab K, Beaulieu C, Ennaji MM, Barakate M. Control of potato soft rot caused by Pectobacterium carotovorum and Pectobacterium atrosepticum by Moroccan actinobacteria isolates. World J Microbiol Biotechnol 2011; 28:303-11. [DOI: 10.1007/s11274-011-0820-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 06/11/2011] [Indexed: 10/18/2022]
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Innes AM, Boycott KM, Puffenberger EG, Redl D, MacDonald IM, Chudley AE, Beaulieu C, Perrier R, Gillan T, Wade A, Parboosingh JS. A founder mutation in BBS2 is responsible for Bardet-Biedl syndrome in the Hutterite population: utility of SNP arrays in genetically heterogeneous disorders. Clin Genet 2011; 78:424-31. [PMID: 20618352 DOI: 10.1111/j.1399-0004.2010.01481.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a multisystem genetically heterogeneous disorder, the clinical features of which are largely the consequence of ciliary dysfunction. BBS is typically inherited in an autosomal recessive fashion, and mutations in at least 14 genes have been identified. Here, we report the identification of a founder mutation in the BBS2 gene as the cause for the increased incidence of this developmental disorder in the Hutterite population. To ascertain the Hutterite BBS locus, we performed a genome-wide single nucleotide polymorphism (SNP) analysis on a single patient and his three unaffected siblings from a Hutterite family. The analysis identified two large SNP blocks that were homozygous in the patient but not in his unaffected siblings, one of these regions contained the BBS2 gene. Sequence analysis and subsequent RNA studies identified and confirmed a novel splice site mutation, c.472-2A>G, in BBS2. This mutation was also found in homozygous form in three subsequently studied Hutterite BBS patients from two different leuts, confirming that this is a founder mutation in the Hutterite population. Further studies are required to determine the frequency of this mutation and its role, if any, in the expression of other ciliopathies in this population.
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Affiliation(s)
- A M Innes
- Department of Medical Genetics, Alberta Children's Hospital and University of Calgary, Calgary, Alberta, Canada
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Pendlebury C, Nzekwu M, Vine D, Beaulieu C, Jetha M, Ball G, Proctor S. Elevated Chylomicron Concentrations in Obese Pre-pubertal Children May be an Early Marker of Cardiovascular Disease Risk. ATHEROSCLEROSIS SUPP 2010. [DOI: 10.1016/j.atherosclerosissup.2010.04.032] [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: 10/19/2022]
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Yenari MA, Lee LK, Beaulieu C, Sun GH, Kunis D, Chang D, Albers GW, Moseley ME, Steinberg GK. Thrombolysis with reteplase, an unglycosylated plasminogen activator variant, in experimental embolic stroke. J Stroke Cerebrovasc Dis 2009; 7:179-86. [PMID: 17895078 DOI: 10.1016/s1052-3057(98)80004-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/1997] [Accepted: 10/21/1997] [Indexed: 01/25/2023] Open
Abstract
We incorporated diffusion-weighted magnetic resonance imaging (MRI) (DWI) and perfusion-weighted MRI (PWI) to evaluate the efficacy of thrombolysis in experimental embolic stroke using a plasminogen activator, reteplase. Reteplase (rPA) is an unglycosylated plasminogen activator with enhanced fibrinolytic potency. Right internal carotid arteries of 34 rabbits were embolized using aged heterologous thrombi. Baseline DWI and PWI scans 0.5 hours after embolization confirmed successful embolization among 32. Intravenous treatment with rPA (n=11; 1 mg/kg bolus), recombinant tissue plasminogen activator (rt-PA) (n=11; 6 mg/kg bolus over 1 hour), or placebo (n=10) commenced 1 hour after stroke induction. MRIs were performed at 1.75, 3, and 5 hours after embolization. Six hours after embolization, brains were harvested and examined for hemorrhage. Posttreatment areas of diffusion abnormality and perfusion delay were graded using both a semiquantitative scale and percent areas expressed as a ratio of the baseline values. Improved perfusion was seen among the rt-PA, and rPA-treated groups compared with placebo, using a semiquantitative scale (P<.01 rt-PA v controls, P<.05, rPA v controls). DWI scans, however, were not improved with thrombolysis. Cerebral hemorrhage was not increased with thrombolytic treatment, although the incidence of wound site hemorrhage was higher with either rPA or rt-PA. One fatal systemic hemorrhage was observed in each of the thrombolytic-treated groups. Cerebral perfusion was equally improved with either rt-PA or rPA without causing excess cerebral hemorrhage. An advantage of rPA is single-bolus dosing rather than continuous infusion. Use of rPA for stroke treatment should be further explored.
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Affiliation(s)
- M A Yenari
- Department of Neurology Stanford University Medical Center, Stanford, CA, USA
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Concha L, Beaulieu C, Collins DL, Gross DW. White-matter diffusion abnormalities in temporal-lobe epilepsy with and without mesial temporal sclerosis. J Neurol Neurosurg Psychiatry 2009; 80:312-9. [PMID: 18977826 DOI: 10.1136/jnnp.2007.139287] [Citation(s) in RCA: 141] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Although epilepsy is considered a grey-matter disorder, changes in the underlying brain connectivity have important implications in seizure generation and propagation. Abnormalities in the temporal and extratemporal white matter of patients with temporal-lobe epilepsy (TLE) and mesial temporal sclerosis (MTS) have previously been identified. Patients with TLE but without MTS often show a different course of the disorder and worse surgical outcome than patients with MTS. The purpose of this study was to determine if said white-matter abnormalities are related to the presence of MTS or if they are also present in non-lesional TLE. METHODS Seventeen patients with TLE and MTS (TLE+uMTS), 13 patients with non-lesional TLE (nl-TLE) and 25 controls were included in the study. Diffusion tensor imaging (DTI) was used to assess tract integrity of the fornix, cingulum, external capsules and the corpus callosum. RESULTS The white-matter abnormalities seen in the fornix appear to be exclusive to patients with MTS. Although the cingulum showed an abnormally high overall diffusivity in both TLE groups, its anisotropy was decreased only in the TLE+uMTS group in a pattern similar to the fornix. The frontal and temporal components of the corpus callosum, as well as the external capsules, demonstrated reduced anisotropy in TLE regardless of MTS. CONCLUSIONS While some white-matter bundles are affected equally in both forms of TLE, abnormalities of the bundles directly related to the mesial temporal structures (ie, the fornix and cingulum) appear to be unique to TLE+uMTS.
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Affiliation(s)
- L Concha
- Department of Biomedical Engineering, University of Alberta, Alberta, Canada
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Beaulieu N, Dupont I, Beaulieu C, Nguyen H, Ste-Croix H, Claridge S, Isakovic L, Vaisburg A, Besterman J, Maroun C. 81 POSTER Preclinical pharmacodynamic markers of MGCD265, a potent orally active c-Met/VEGFR multitargeted kinase inhibitor in Phase I clinical trials. European Journal of Cancer Supplements 2008. [DOI: 10.1016/s1359-6349(08)72013-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Han L, Dutilleul P, Prasher SO, Beaulieu C, Smith DL. Assessment of common scab-inducing pathogen effects on potato underground organs via computed tomography scanning. Phytopathology 2008; 98:1118-25. [PMID: 18943458 DOI: 10.1094/phyto-98-10-1118] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Common scab caused by Streptomyces scabies is a major bacterial disease of potato (Solanum tuberosum). Its best known symptom is superficial lesions on the surface of progeny potato tubers, observed at harvesting. In this study, effects of S. scabies on space occupancy by underground organs and on structural complexity of root systems are investigated during growth via computed tomography (CT) scanning. Two groups of potato plants were grown in a greenhouse in middle-sized plastic pots. Using a high-resolution X-ray CT scanner formerly used for medical applications, their underground organs and surrounding medium (sieved and autoclaved homogeneous sand) were submitted to CT scanning 4, 6, and 8 weeks after planting. For one group, sand was inoculated with the common scab-inducing pathogen (S. scabies EF-35) at potting. Space occupancy by underground organs was estimated via curve fitting applied to histograms of CT scan data, while three-dimensional skeletal images were used for fractal analysis. Root systems of diseased plants were found to be less complex than those of healthy plants 4 weeks after planting, and the relative growth rates derived from space occupancy measures were of different sign between the two groups from week 4 to week 8.
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Affiliation(s)
- L Han
- Department of Plant Science, McGill University, Bellevue, Canada
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Lebel C, Walker L, Leemans A, Phillips L, Beaulieu C. Microstructural maturation of the human brain from childhood to adulthood. Neuroimage 2008; 40:1044-55. [PMID: 18295509 DOI: 10.1016/j.neuroimage.2007.12.053] [Citation(s) in RCA: 978] [Impact Index Per Article: 61.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 09/14/2007] [Accepted: 12/23/2007] [Indexed: 12/11/2022] Open
Abstract
Brain maturation is a complex process that continues well beyond infancy, and adolescence is thought to be a key period of brain rewiring. To assess structural brain maturation from childhood to adulthood, we charted brain development in subjects aged 5 to 30 years using diffusion tensor magnetic resonance imaging, a novel brain imaging technique that is sensitive to axonal packing and myelination and is particularly adept at virtually extracting white matter connections. Age-related changes were seen in major white matter tracts, deep gray matter, and subcortical white matter, in our large (n=202), age-distributed sample. These diffusion changes followed an exponential pattern of maturation with considerable regional variation. Differences observed in developmental timing suggest a pattern of maturation in which areas with fronto-temporal connections develop more slowly than other regions. These in vivo results expand upon previous postmortem and imaging studies and provide quantitative measures indicative of the progression and magnitude of regional human brain maturation.
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Affiliation(s)
- C Lebel
- Department of Biomedical Engineering, Faculty of Medicine and Dentistry, Room 1098 Research Transition Facility, University of Alberta, Edmonton, Alberta, Canada T6G 2V2
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Errakhi R, Dauphin A, Meimoun P, Lehner A, Reboutier D, Vatsa P, Briand J, Madiona K, Rona JP, Barakate M, Wendehenne D, Beaulieu C, Bouteau F. An early Ca2+ influx is a prerequisite to thaxtomin A-induced cell death in Arabidopsis thaliana cells. J Exp Bot 2008; 59:4259-70. [PMID: 19015217 DOI: 10.1093/jxb/ern267] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The pathogenicity of various Streptomyces scabies isolates involved in potato scab disease was correlated with the production of thaxtomin A. Since calcium is known as an essential second messenger associated with pathogen-induced plant responses and cell death, it was investigated whether thaxtomin A could induce a Ca2+ influx related to cell death and to other putative plant responses using Arabidopsis thaliana suspension cells, which is a convenient model to study plant-microbe interactions. A. thaliana cells were treated with micromolar concentrations of thaxtomin A. Cell death was quantified and ion flux variations were analysed from electrophysiological measurements with the apoaequorin Ca2+ reporter protein and by external pH measurement. Involvement of anion and calcium channels in signal transduction leading to programmed cell death was determined by using specific inhibitors. These data suggest that this toxin induces a rapid Ca2+ influx and cell death in A. thaliana cell suspensions. Moreover, these data provide strong evidence that the Ca2+ influx induced by thaxtomin A is necessary to achieve this cell death and is a prerequisite to early thaxtomin A-induced responses: anion current increase, alkalization of the external medium, and the expression of PAL1 coding for a key enzyme of the phenylpropanoid pathway.
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Affiliation(s)
- R Errakhi
- LEM (EA 3514), Université Paris Diderot-Paris7, 2, place Jussieu, F-75251 Paris cedex 05, France
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El Adlouni S, Beaulieu C, Ouarda TBMJ, Gosselin PL, Saint-Hilaire A. Effects of climate on West Nile Virus transmission risk used for public health decision-making in Quebec. Int J Health Geogr 2007; 6:40. [PMID: 17883862 PMCID: PMC2137925 DOI: 10.1186/1476-072x-6-40] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Accepted: 09/20/2007] [Indexed: 11/29/2022] Open
Abstract
Background In 2002, major human epidemics of West Nile Virus (WNV) were reported in five cities in the North East region of North America. The present analysis examines the climatic conditions that were conducive to the WNV epidemic, in order to provide information to public health managers who eventually must decide on the implementation of a preventive larvicide spraying program in Quebec, Canada. Two sets of variables, the first observed in the summer of 2002 and the second in the preceding winter were analysed to study their potential as explanatory variables for the emergence of the virus at epidemic levels. Results Results show that the climatic conditions observed in the year 2002 have contributed to the emergence of the virus and can be observed once every forty years on average. The analysis has shown that the 2002 events observed in several North East North American cities are characterized by two main variables: the number of degree-days below -5°C in the winter (DD-5) and the number of degree-days greater than 25°C in the summer (DD25). Conclusion In the context of a declining rate of human and aviary infection to WNV, this element contributed to the decision to suspend the use of preventive larvicides in the province of Quebec in 2006 and for the foreseeable future. The second part of this study indicates that it is very important to estimate the risk that extreme values can be observed simultaneously in the summer and in the winter preceding the appearance of the virus. The proposed models provide important information to public health officials, weeks before the appearance of the virus, and can therefore be useful to help prevent human epidemics.
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Affiliation(s)
- Salaheddine El Adlouni
- Hydro-Quebec/NSERC Chair in Statistical Hydrology, Canada Research Chair on the Estimation of Hydrological Variables, University of Quebec, INRS-ETE, 490, de la Couronne, Quebec (QC) G1K 9A9, CANADA
| | - Claudie Beaulieu
- Hydro-Quebec/NSERC Chair in Statistical Hydrology, Canada Research Chair on the Estimation of Hydrological Variables, University of Quebec, INRS-ETE, 490, de la Couronne, Quebec (QC) G1K 9A9, CANADA
| | - Taha BMJ Ouarda
- Hydro-Quebec/NSERC Chair in Statistical Hydrology, Canada Research Chair on the Estimation of Hydrological Variables, University of Quebec, INRS-ETE, 490, de la Couronne, Quebec (QC) G1K 9A9, CANADA
| | - Pierre L Gosselin
- Institut National de Santé Publique du Québec and Université Laval, 945, avenue Wolfe, Quebec (Quebec)G1V5B3, CANADA
| | - André Saint-Hilaire
- Hydro-Quebec/NSERC Chair in Statistical Hydrology, Canada Research Chair on the Estimation of Hydrological Variables, University of Quebec, INRS-ETE, 490, de la Couronne, Quebec (QC) G1K 9A9, CANADA
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Sundaram P, Zomorodian A, Beaulieu C, Napel S. Colon polyp detection using smoothed shape operators: preliminary results. Med Image Anal 2007; 12:99-119. [PMID: 17910934 DOI: 10.1016/j.media.2007.08.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 07/25/2007] [Accepted: 08/03/2007] [Indexed: 10/22/2022]
Abstract
Computer-aided detection (CAD) algorithms identify locations in computed tomographic (CT) images of the colon that are most likely to contain polyps. Existing CAD methods treat the CT data as a voxelized, volume image. They estimate a curvature-based feature at the mucosal surface voxels. However, curvature is a smooth notion, while our data are discrete and noisy. As a second order differential quantity, curvature amplifies noise. In this paper, we present the smoothed shape operators method (SSO), which uses a geometry processing approach. We extract a triangle mesh representation of the colon surface, and estimate curvature on this surface using the shape operator. We then smooth the shape operators on the surface iteratively. Throughout, we use techniques explicitly designed for discrete geometry. All our computation occurs on the surface, rather than in the voxel grid. We evaluate our algorithm on patient data and provide free-response receiver-operating characteristic performance analysis over all size ranges of polyps. We also provide confidence intervals for our performance estimates. We compare our performance with the surface normal overlap (SNO) method for the same data. A preliminary evaluation of our method on 35 patients yielded the following results (polyp diameter range; sensitivity; false positives/case): (10mm; 100%; 17.5), (5-10 mm; 89.7%, 21.23), (<5 mm; 59.1%; 23.9) and (overall; 80.3%; 23.9). The evaluation of the SNO method yielded: (10 mm; 75%; 17.5), (5-10 mm; 43.1%; 21.23), (<5 mm; 15.9%; 23.9) and (overall; 38.5%; 23.9).
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Affiliation(s)
- P Sundaram
- Department of Radiology, Stanford University, Stanford, CA 94305, United States.
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Abstract
Clinical studies in adults indicate there is a positive and significant association between insulin resistance, dyslipidaemia, fasting intestinally derived lipoproteins [via apoB48 (apolipoprotein B48)] and visceral fat. All of these factors contribute to increased risk of CVD (cardiovascular disease). Since little is known about postprandial dyslipidaemia in overweight children, we sought to compare fasting levels of apoB48 with the HOMA-IR (homoeostasis model assessment of insulin resistance) score, classic lipid profile and VAT (visceral adipose tissue). Pre-pubertal, overweight boys and girls were recruited from the wider-Edmonton area (Alberta). Body composition was determined using both dual-energy X-ray absorptiometry and MRI (magnetic resonance imaging). Fasting apoB48 was quantified in plasma using an adapted SDS/PAGE immunoblotting technique, and insulin, glucose, TC (total cholesterol), TAG (triacylglycerol), LDL (low-density lipoprotein) and HDL (high-density lipoprotein) were determined by calorimetric assay. In this overweight sample, we observed elevated fasting apoB48 concentrations, greater than the normal adult range. In addition, apoB48 was significantly related to HOMA-IR and TAG levels. Although apoB48 was positively correlated with TC and LDL and negatively associated with HDL, these relationships did not achieve significance. Our ongoing MRI analysis reveals a positive relationship between apoB48 and VAT volume. To our knowledge, this is the first study to report apoB48 concentrations in overweight pre-pubertal children. Thus this article will provide a brief rationale for our study and its methodology.
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Affiliation(s)
- M M U Nzekwu
- Alberta Institute For Human Nutrition, University of Alberta, Edmonton, Alberta, Canada
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Vander Pluym J, Shan WW, Taher Z, Beaulieu C, Plewes C, Peterson AE, Beattie OB, Bamforth JS. Use of magnetic resonance imaging to measure facial soft tissue depth. Cleft Palate Craniofac J 2007; 44:52-7. [PMID: 17214523 DOI: 10.1597/04-191] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [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: 11/22/2022] Open
Abstract
OBJECTIVE To investigate the feasibility of using magnetic resonance imaging to estimate facial tissue depth at standard anthropological facial landmarks. DESIGN Standard facial landmarks were marked with magnetic resonance imaging opaque markers on 10 normal subjects. Three observers estimated facial tissue depth at these landmarks on up to three separate occasions, and comparisons were made among the observers. SETTING The study was conducted with volunteers at the University of Alberta Biomechanical Engineering unit. PARTICIPANTS The volunteers were healthy individuals of both sexes between the ages of 18 and 30 years. MAIN OUTCOME MEASURES The technical error of measurement among observers was used as the main indicator of precision of measurement. RESULTS Measurements of tissue depth showed tolerable technical error of measurement and were precisely measured within and among observers. CONCLUSIONS Magnetic resonance images can be used to estimate tissue depth in human faces with precision.
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Affiliation(s)
- J Vander Pluym
- Department of Medical Genetics, University of Alberta, Edmonton, Canada
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Bhagat YA, Emery DJ, Naik S, Yeo T, Beaulieu C. Comparison of generalized autocalibrating partially parallel acquisitions and modified sensitivity encoding for diffusion tensor imaging. AJNR Am J Neuroradiol 2007; 28:293-8. [PMID: 17296998 PMCID: PMC7977396] [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: 05/13/2023]
Abstract
BACKGROUND AND PURPOSE Diffusion tensor magnetic resonance imaging (DTI) of the brain is usually acquired with single-shot echo-planar imaging, which is associated with localized signal loss, geometric distortions, and blurring. Parallel imaging can lessen these artifacts by shortening the length of the echo-train acquisition. The self-calibrating parallel acquisition techniques, image domain-based modified sensitivity encoding (mSENSE) and k-space-based generalized autocalibrating partially parallel acquisitions (GRAPPA), were evaluated with DTI of the brain in 5 healthy subjects. METHODS GRAPPA and mSENSE with higher acceleration factors (R) up to 4 were compared with conventional DTI (with and without phase partial Fourier, another method of reducing the echo-train length) on a 1.5T Sonata scanner (Siemens, Erlangen, Germany). The resulting images and diffusion maps were evaluated qualitatively and quantitatively. Qualitative analysis was performed by 3 reviewers blinded to the technique using image sharpness and the level of artifacts as characteristics for scoring each set of images. Quantitative comparisons encompassed measuring signal-to-noise ratio, Trace/3 apparent diffusion coefficient (ADC), and fractional anisotropy (FA) in 6 white-matter (WM) and gray-matter (GM) regions. RESULTS Reviewers scored the GRAPPA and mSENSE R = 2 images better than images acquired with conventional techniques. FA contrast was improved at the GM/WM junction in peripheral brain areas. Trace/3 ADC and FA measurements were consistent for all methods. However, R = 3,4 images suffered from reconstruction-related artifacts. CONCLUSIONS GRAPPA and mSENSE (R = 2) minimized the susceptibility and off-resonance effects associated with conventional DTI methods, yielding high-quality images and reproducible quantitative diffusion measurements.
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Affiliation(s)
- Y A Bhagat
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
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Macleod R, Beaulieu N, Isakovic L, Nguyen H, Chute I, Beaulieu C, Claridge S, Saavedra O, Besterman J, Vaisburg A. 410 POSTER Identification and characterization of novel, orally active inhibitors of c-MET and Ron receptor tyrosine kinases. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)70415-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Dallaire R, LeBlanc DI, Tranchant CC, Vasseur L, Delaquis P, Beaulieu C. Monitoring the microbial populations and temperatures of fresh broccoli from harvest to retail display. J Food Prot 2006; 69:1118-25. [PMID: 16715813 DOI: 10.4315/0362-028x-69.5.1118] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [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: 11/11/2022]
Abstract
Microbial populations and the temperature of fresh broccoli were monitored at several steps of a supply chain by sampling 33 distinct lots of locally grown produce over two seasons during harvest, storage, wholesale handling, and retail display. Imported broccoli was also sampled, but only at retail display. Microbiological analyses were conducted on the florets of 201 local and 60 imported broccoli samples to determine populations of total aerobic bacteria (aerobic colony count), fecal coliforms, Escherichia coli, and Listeria monocytogenes. All the samples had mean aerobic colony counts ranging between 4 and 6 log CFU/g, but L. monocytogenes was not detected (limit of detection =100 CFU/g). Fecal coliforms and E. coli (limit of detection =20 most probable number per 100 g) were found in 22 of 126 samples of local broccoli collected at various steps of the production and distribution system during the first season. None was found in 75 samples collected in the second season. Fecal coliforms and E. coli were found in 2 of 60 imported broccoli samples. Broccoli temperatures were relatively well controlled throughout the production and distribution system. No clear change in produce microbial populations was evident between harvest and retail display, during both sampling seasons. However, a large experimental variability was found, possibly associated with the high variability of the initial levels of microbial populations on broccoli at harvest.
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Affiliation(s)
- R Dallaire
- Biology Department, Université de Moncton, Moncton, New Brunswick, Canada
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Doumbou C, Hamby Salove M, Crawford D, Beaulieu C. Actinomycetes, promising tools to control plant diseases and to promote plant growth. ACTA ACUST UNITED AC 2005. [DOI: 10.7202/706219ar] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.6] [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
Actinomycetes represent a high proportion of the soil microbial biomass and have the capacity to produce a wide variety of antibiotics and of extracellular enzymes. Several strains of actinomycetes have been found to protect plants against plant diseases. This review focuses on the potential of actinomycetes as (a) source of agroactive compounds, (b) plant growth promoting organisms, and (c) biocontrol tools of plant diseases. This review also addresses examples of biological control of fungal and bacterial plant pathogens by actinomycetes species which have already reached the market or are likely to be exploited commercially within the next few years.
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Agbessi S, Beauséjour J, Déry C, Beaulieu C. Antagonistic properties of two recombinant strains of Streptomyces melanosporofaciens obtained by intraspecific protoplast fusion. Appl Microbiol Biotechnol 2003; 62:233-8. [PMID: 12883869 DOI: 10.1007/s00253-003-1256-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2002] [Revised: 12/17/2002] [Accepted: 01/03/2003] [Indexed: 12/01/2022]
Abstract
Intraspecific protoplast fusion was used to produce stable prototrophic recombinants of Streptomyces melanosporofaciens EF-76, a biocontrol agent of plant disease producing geldanamycin. Two recombinant strains (FP-54 and FP-60) that differed with regard to their antagonistic properties against Bacillus cereus ATCC 14579, Streptomyces scabies EF-35 and Phytophthora fragariae var. rubi 390 were characterized. FP-60 lost the ability to inhibit the in vitro growth of these microbial strains while FP-54 exhibited higher antagonistic activities against them. FP-60 was deficient in geldanamycin biosynthesis whereas FP-54 was shown to produce, in addition to geldanamycin, at least two other antimicrobial compounds that were absent in the culture supernatants of strain EF-76. Like the wild-type strain EF-76, strain FP-54 reduced common scab symptoms on potato tuber but no significant difference was observed between the disease index attributed to tubers treated with strain EF-76 or with strain FP-54. Strain FP-60 showed no protective effect against common scab. The disease index of tubers treated with this recombinant was worse than the index associated with potato tubers from control treatments.
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Affiliation(s)
- S Agbessi
- Centre d'étude et de valorisation de la diversité microbienne, Département de biologie, Université de Sherbrooke, 2500 Boulevard Université, J1 K 2R1, Sherbrooke, Québec, Canada
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Engelhorn T, Doerfler A, de Crespigny A, Beaulieu C, Forsting M, Moseley ME. Multilocal magnetic resonance perfusion mapping comparing the cerebral hemodynamic effects of decompressive craniectomy versus reperfusion in experimental acute hemispheric stroke in rats. Neurosci Lett 2003; 344:127-31. [PMID: 12782343 DOI: 10.1016/s0304-3940(03)00441-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [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: 11/23/2022]
Abstract
This study examined the hemodynamic effects of craniectomy compared to reperfusion on the temporal evolution of cerebral perfusion in different brain regions in a rat model of focal cerebral ischemia. Three groups were investigated: no treatment, reperfusion or craniectomy at 1 h. Perfusion-weighted magnetic resonance imaging (PWI) was performed serially from 0.5 to 6 h. Relative regional cerebral blood flow was calculated for different regions and infarct volume was assessed by histology at 24 h. As conclusion, both, craniectomy and reperfusion increased cerebral perfusion in the acute phase of cerebral ischemia. While reperfusion resulted in a homogeneous improvement of perfusion in the cortex and basal ganglia, craniectomy improved only cortical perfusion in areas directly under the craniectomy site. PWI is well suited to non-invasively monitor perfusion alterations after aggressive therapeutical approaches in stroke.
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Affiliation(s)
- T Engelhorn
- Department of Neuroradiology, Essen University School of Medicine, Hufelandstrasse 55, D-45122 Essen, Germany.
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Langlois P, Bourassa S, Poirier GG, Beaulieu C. Identification of Streptomyces coelicolor proteins that are differentially expressed in the presence of plant material. Appl Environ Microbiol 2003; 69:1884-9. [PMID: 12676660 PMCID: PMC154778 DOI: 10.1128/aem.69.4.1884-1889.2003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2002] [Accepted: 11/11/2002] [Indexed: 11/20/2022] Open
Abstract
Streptomyces coelicolor and Lemna minor were used as a model to study the modulation of bacterial gene expression during plant-streptomycete interactions. S. coelicolor was grown in minimal medium with and without L. minor fronds. Bacterial proteomes were analyzed by two-dimensional gel electrophoresis, and a comparison of the two culture conditions resulted in identification of 31 proteins that were induced or repressed by the presence of plant material. One-half of these proteins were identified by peptide mass fingerprinting by using matrix-assisted laser desorption ionization-time of flight mass spectrometry. The induced proteins were involved in energetic metabolism (glycolysis, pentose phosphate pathway, oxidative phosphorylation), protein synthesis, degradation of amino acids, alkenes, or cellulose, tellurite resistance, and growth under general physiological or oxidative stress conditions. The repressed proteins were proteins synthesized under starvation stress conditions. These results suggest that root exudates provide additional carbon sources to the bacteria and that physiological adaptations are required for efficient bacterial growth in the presence of plants.
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Affiliation(s)
- P Langlois
- Centre d'Etude et de Valorisation de la Diversité Microbienne, Département de Biologie, Université de Sherbrooke, Québec, Canada J1K 2R1
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Hawari J, Halasz A, Groom C, Deschamps S, Paquet L, Beaulieu C, Corriveau A. Photodegradation of RDX in aqueous solution: a mechanistic probe for biodegradation with Rhodococcus sp. Environ Sci Technol 2002; 36:5117-5123. [PMID: 12523428 DOI: 10.1021/es0207753] [Citation(s) in RCA: 22] [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] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Recently we demonstrated that Rhodococcus sp. strain DN22 degraded hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) (1) aerobically via initial denitration followed by ring cleavage. Using UL 14C-[RDX] and ring labeled 15N-[RDX] approximately 30% of the energetic chemical mineralized (one C atom) and 64% converted to a dead end product that was tentatively identified as 4-nitro-2,4-diaza-butanal (OHCHNCH2NHNO2). To have further insight into the role of initial denitration on RDX decomposition, we photolyzed the energetic chemical at 350 nm and pH 5.5 and monitored the reaction using a combination of analytical techniques. GC/ MS-PCI showed a product with a [M+H] at 176 Da matching a molecular formula of C3H5N5O4 that was tentatively identified as the initially denitrated RDX product pentahydro-3,5-dinitro-1,3,5-triazacyclohex-1-ene (II). LC/MS (ES-) showed that the removal of RDX was accompanied by the formation of two other key products, each showing the same [M-H] at 192 Da matching a molecular formula of C3H7N5O5. The two products were tentatively identified as the carbinol (III) of the enamine (II) and its ring cleavage product O2NNHCH2NNO2CH2NHCHO (IV). Interestingly, the removal of III and IV was accompanied by the formation and accumulation of OHCHNCH2NHNO2 that we detected with strain DN22. At the end of the experiment, which lasted 16 h, we detected the following products HCHO, HCOOH, NH2CHO, N2O, NO2-, and NO3-. Most were also detected during RDX incubation with strain DN22. Finally, we were unable to detect any of RDX nitroso products during both photolysis and incubation with the aerobic bacteria, emphasizing that initial denitration in both cases was responsible for ring cleavage and subsequent decomposition in water.
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Affiliation(s)
- J Hawari
- Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec, H4P 2R2, Quebec, Canada.
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Halasz A, Groom C, Zhou E, Paquet L, Beaulieu C, Deschamps S, Corriveau A, Thiboutot S, Ampleman G, Dubois C, Hawari J. Detection of explosives and their degradation products in soil environments. J Chromatogr A 2002; 963:411-8. [PMID: 12187997 DOI: 10.1016/s0021-9673(02)00553-8] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [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: 11/18/2022]
Abstract
Polynitro organic explosives [hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and 2,4,6-trinitrotoluene (TNT)] are typical labile environmental pollutants that can biotransform with soil indigenous microorganisms, photodegrade by sunlight and migrate through subsurface soil to cause groundwater contamination. To be able to determine the type and concentration of explosives and their (bio)transformation products in different soil environments, a comprehensive analytical methodology of sample preparation, separation and detection is thus required. The present paper describes the use of supercritical carbon dioxide (SC-CO2), acetonitrile (MeCN) (US Environmental Protection Agency Method 8330) and solid-phase microextraction (SPME) for the extraction of explosives and their degradation products from various water, soil and plant tissue samples for subsequent analysis by either HPLC-UV, capillary electrophoresis (CE-UV) or GC-MS. Contaminated surface and subsurface soil and groundwater were collected from either a TNT manufacturing facility or an anti-tank firing range. Plant tissue samples were taken fromplants grown in anti-tank firing range soil in a greenhouse experiment. All tested soil and groundwater samples from the former TNT manufacturing plant were found to contain TNT and some of its amino reduced and partially denitrated products. Their concentrations as determined by SPME-GC-MS and LC-UV depended on the location of sampling at the site. In the case of plant tissues, SC-CO2 extraction followed by CE-UV analysis showed only the presence of HMX. The concentrations of HMX (<200 mg/kg) as determined by supercritical fluid extraction (SC-CO2)-CE-UV were comparable to those obtained by MeCN extraction, although the latter technique was found to be more efficient at higher concentrations (>300 mg/kg). Modifiers such as MeCN and water enhanced the SC-CO2 extractability of HMX from plant tissues.
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Affiliation(s)
- A Halasz
- Biotechnology Research Institute, National Research Council Canada, Montreal, Quebec
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Abstract
The morphology and postsynaptic targets of GABA-containing boutons were determined in the striate cortex of cat, using a postembedding immunocytochemical technique at the electron microscopic level. Two types of terminals, both making symmetrical synaptic contacts, were GABA-positive. The first type (95% of all GABA-positive boutons) contained small pleomorphic vesicles, the second type (5%) contained larger ovoid vesicles. Furthermore, 99% of all cortical boutons containing pleomorphic vesicles were GABA positive, and all boutons with pleomorphic vesicles made symmetrical synaptic contacts. These results together with previously published stereological data (Beaulieu and Colonnier, 1985, 1987) were used to estimate the density of GABA-containing synapses, which is about 48 million/mm3 in the striate cortex. The postsynaptic targets of GABA positive boutons were also identified and the distribution was calculated to be as follows: 58% dendritic shafts, 26.4% dendritic spines, 13.1% somata and 2.5% axon initial segments. A total of 11% of the postsynaptic targets were GABA immunoreactive and therefore originated from GABAergic neurons. The results demonstrate that the majority of GABAergic synapses exert their action on the membrane of dendrites and spines rather than on the somata and axons of neurons.
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Affiliation(s)
- C. Beaulieu
- Medical Research Council, Anatomical Neuropharmacology Unit, Department of Pharmacology, Oxford University, South Parks Road, Oxford OX1 3QT, UK
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Lavoie R, Bouchain G, Frechette S, Woo SH, Abou-Khalil E, Leit S, Fournel M, Yan PT, Trachy-Bourget MC, Beaulieu C, Li Z, Besterman J, Delorme D. Design and synthesis of a novel class of histone deacetylase inhibitors. Bioorg Med Chem Lett 2001; 11:2847-50. [PMID: 11597413 DOI: 10.1016/s0960-894x(01)00552-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [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
Histone deacetylase inhibitors (HDACs) have emerged as a novel class of antiproliferative agents. Utilizing structure-based design, the synthesis of a series of sulfonamide hydroxamic acids is described. Further optimization of this series by substitution of the terminal aromatic ring yielded HDAC inhibitors with good in vitro and in vivo activities.
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Affiliation(s)
- R Lavoie
- Department of Medicinal Chemistry, MethylGene Inc., 7220 Frederick-Banting, Montréal, Québec, Canada H4S 2A1
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Jordan P, Hadcock W, Beaulieu C, Kamada S, Vomacka J, Garrett D, Frye L. Decreasing process variation in the care of carotid endarterectomy patients. Top Health Inf Manage 2001; 22:24-34. [PMID: 11761789] [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: 02/23/2023]
Abstract
Avoidable complications after successful carotid endarterectomy surgery typically occur in the immediate postoperative period; most of these complications are related to hemodynamic instability. At Saint Agnes Medical Center, process variation resulted from 22 anesthesiologists and 11 surgeons doing the same process 242 ways. We introduced a Post-Anesthesia Care Unit Carotid Order Set to standardize the process, drug sequence, and drug choices for postoperative carotid endarterectomy patients. Ongoing monitoring demonstrated that this reduction in process variability resulted in a lower complication rate for stroke and wound hematoma.
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Affiliation(s)
- P Jordan
- Saint Agnes Medical Center, Fresno, California, USA
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