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  1. Article: T8 spinal cord transection in a 6-year-old child.

    St Clair, Selvon F / Silverstein, Michael / Lieberman, Isador

    Evidence-based spine-care journal

    2013  Volume 3, Issue 3, Page(s) 57–61

    Abstract: Study design:  Case report.: Objective:  To describe a case of spinal cord transection in a 6-year-old child.: Background information:  Non-missile injury of the spinal cord is not common and its incidence varies according to the country. In ... ...

    Abstract Study design:  Case report.
    Objective:  To describe a case of spinal cord transection in a 6-year-old child.
    Background information:  Non-missile injury of the spinal cord is not common and its incidence varies according to the country. In addition, to our knowledge, there are no published reports of spinal cord injury (SCI) from a penetrating nail. Here, we report the case of a child who developed complete SCI because of cord transection by a nail.
    Methods:  A detailed history and physical examination were performed along with careful review of the patient's medical records. In addition, a review of the literature was conducted to assess the incidence and treatment of similar injuries.
    Case description:  A 6-year-old boy was admitted to the hospital after falling from a tree and landing on a nail. His physical examination revealed an emaciated child with multiple decubitus ulcers, lying on his side in bed. Visible was a well-healed posterior puncture wound at the T8 vertebral level. On neurological examination, the patient had 0/5 muscle strength in his lower extremities, symmetrical areflexia, and hypoesthesia below the T8 level. Plain x-ray of the thoracolumbar spine was normal. Magnetic resonance imaging revealed a transected spinal cord at the T8 vertebra, consistent with his nail puncture wound.
    Discussion:  This report describes an unusual case of a complete SCI in a pediatric patient caused by penetrating trauma from a nail. To our knowledge, this is the first case to report on complete SCI due to trauma from a nail.
    Language English
    Publishing date 2013-03-14
    Publishing country Germany
    Document type Case Reports
    ZDB-ID 2567155-8
    ISSN 1869-4136 ; 1663-7976
    ISSN (online) 1869-4136
    ISSN 1663-7976
    DOI 10.1055/s-0032-1327811
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Oblique lumbar interbody fixation: a biomechanical study in human spines.

    St Clair, Selvon / Tan, Juay Seng / Lieberman, Isador

    Journal of spinal disorders & techniques

    2012  Volume 25, Issue 4, Page(s) 183–189

    Abstract: Study design: In vitro spine biomechanics.: Objective: To determine the biomechanical properties of oblique lumbar interbody fixation (OLIF) in human cadaveric spines.: Summary of background data: OLIF has been used for stabilization of ... ...

    Abstract Study design: In vitro spine biomechanics.
    Objective: To determine the biomechanical properties of oblique lumbar interbody fixation (OLIF) in human cadaveric spines.
    Summary of background data: OLIF has been used for stabilization of degenerative spondylolisthesis at the lumbosacral junction. Biomechanical properties and mode of failure of OLIF as a standalone device for motion segments without sagittal deformity has not yet been investigated. We hypothesize that the biomechanical properties of OLIF will be comparable with the contemporary standard of pedicle screw (PS) fixation.
    Method: Randomly matched motion segments from L1 to L5 were allocated into 2 groups: (A) OLIF (group 1, n=5) or (B) PS (group 2, n=5). The intact and instrumented motion segments with and without anterior interbody graft were first tested under a combination of 200N axial compression and 5 Nm bending moments in flexion-extension and in lateral bending. Range of motion (ROM) and neutral zone were determined and compared between intact, OLIF and PS. A final load to failure test was carried out for each motion segment in either flexion or extension.
    Result: OLIF resulted in reduction of flexion-extension ROM to 36%±14% of intact whereas PS resulted in reduction to 27%±22% of intact. The reduction of lateral bending ROM were 32%±13% and 32%±24% of intact with OLIF and PS. There were no significant difference in ROM between OLIF and PS (P=0.39). The mean failure loads with OLIF and PS in flexion were 1284 and 1158N, and in extension were 1879 and 1934N, respectively. Failure occurred at the ventral screw bone interface without pedicle fracture.
    Conclusions: These results indicate that stiffness and load to failure of the OLIF is comparable with PS fixation. OLIF failure occurred ventrally through the anterior cortical rim without concomitant pedicle fracture.
    MeSH term(s) Aged ; Aged, 80 and over ; Biomechanical Phenomena ; Bone Screws ; Cadaver ; Female ; Humans ; Lumbar Vertebrae/physiopathology ; Lumbar Vertebrae/surgery ; Male ; Middle Aged ; Range of Motion, Articular ; Spinal Fusion/instrumentation ; Spinal Fusion/methods ; Spondylolisthesis/surgery
    Language English
    Publishing date 2012-06
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2075910-1
    ISSN 1539-2465 ; 1536-0652
    ISSN (online) 1539-2465
    ISSN 1536-0652
    DOI 10.1097/BSD.0b013e318211fc6b
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Percutaneous lumbar and thoracic pedicle screws: a trauma experience.

    Park, Daniel K / Thomas, Anil O / St Clair, Selvon / Bawa, Maneesh

    Journal of spinal disorders & techniques

    2014  Volume 27, Issue 3, Page(s) 154–161

    Abstract: Design: Retrospective case study.: Objective: Percutaneous pedicle screw (PPS) techniques do not allow direct visualization and may lead to erroneous screw placement. A technique utilizing only fluoroscopy is described. Verification of its accuracy ... ...

    Abstract Design: Retrospective case study.
    Objective: Percutaneous pedicle screw (PPS) techniques do not allow direct visualization and may lead to erroneous screw placement. A technique utilizing only fluoroscopy is described. Verification of its accuracy and morphometric validation are presented.
    Background: Minimally invasive spine surgical techniques, particularly PPS placement, have been growing in popularity. The purported benefits of minimally invasive spine surgical stated may be even more advantageous in the trauma setting.
    Methods: Jamshidi needles were docked in the typical starting position verified with posterior-anterior image. Jamshidi needle (20 mm) was advanced ensuring that the tip remained lateral to the medial pedicle wall. A Kirschner (K-wire) was placed through the needle. Once all the K-wires were placed, a lateral image was taken confirming the correct trajectory and that the wire passed the posterior vertebral body wall. Patients with PPS fixation were retrospectively studied with postoperative computed tomography to verify screw accuracy. Screw grade was assessed as grade I when completely within the pedicle, II <2 mm, III 2-4 mm, and IV >4 mm outside the pedicle. Morphometrically, 40 thoracic and lumbar computed tomography scans of patients (<40 y) without spine fractures were reviewed. The pedicle length was defined as the distance from the dorsal cortical margin to the posterior vertebral body in the pedicle's midaxis.
    Results: A total of 172 screws were placed. Eighteen percent were found to have cortical breach, but only 2.9% were found to have >grade II breach. The morphometric study demonstrated the pedicle length to range from 14.4 to 22.1 mm. The shortest was in the upper thoracic and the longest at L1-L2.
    Conclusions: The morphometric study demonstrates if a K-wire is placed 20 mm into the bone and remains lateral to the medial pedicle wall and the tip just engages the vertebral body, the screw trajectory is safe particularly in the lower thoracic and upper lumbar spine. A smaller distance may be utilized in the upper thoracic. Breach rates are similar to other reports using other techniques; none were clinically significant. The advantage of this technique is the use of only PA fluoroscopy for placing all the wires percutaneously.
    MeSH term(s) Accidents, Traffic ; Adult ; Aged ; Bone Screws ; Fluoroscopy ; Humans ; Ligaments/surgery ; Lumbar Vertebrae/diagnostic imaging ; Lumbar Vertebrae/surgery ; Middle Aged ; Retrospective Studies ; Spinal Fusion/methods ; Thoracic Vertebrae/diagnostic imaging ; Thoracic Vertebrae/surgery ; Tomography, X-Ray Computed ; Treatment Outcome ; Wounds and Injuries/surgery ; Young Adult
    Language English
    Publishing date 2014-05
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2075910-1
    ISSN 1539-2465 ; 1536-0652
    ISSN (online) 1539-2465
    ISSN 1536-0652
    DOI 10.1097/BSD.0b013e318250ec75
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Your diagnosis? Pott's disease.

    Silverstein, Michael P / Lieberman, Isador H / St Clair, Selvon / Kayanja, Mark / Bancroft, Laura W

    Orthopedics

    2012  Volume 35, Issue 4, Page(s) 257, 344–7

    MeSH term(s) Child ; Diagnosis, Differential ; Humans ; Male ; Radiography ; Spinal Curvatures/complications ; Spinal Curvatures/diagnostic imaging ; Tuberculosis, Spinal/complications ; Tuberculosis, Spinal/diagnostic imaging
    Language English
    Publishing date 2012-04
    Publishing country United States
    Document type Case Reports ; Journal Article
    ZDB-ID 424447-3
    ISSN 1938-2367 ; 0147-7447
    ISSN (online) 1938-2367
    ISSN 0147-7447
    DOI 10.3928/01477447-20120327-02
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Thoracic pedicle subtraction osteotomy in a pediatric patient: a case report.

    Silverstein, Michael P / St Clair, Selvon F / Lieberman, Isador H

    Evidence-based spine-care journal

    2012  Volume 3, Issue 2, Page(s) 49–54

    Abstract: Study design:  Case report.: Objective:  To describe a case of thoracic pedicle subtraction osteotomy (PSO) for congenital kyphosis in a child.: Background information:  Although congenital kyphosis is rare, it is a challenging cause of pediatric ... ...

    Abstract Study design:  Case report.
    Objective:  To describe a case of thoracic pedicle subtraction osteotomy (PSO) for congenital kyphosis in a child.
    Background information:  Although congenital kyphosis is rare, it is a challenging cause of pediatric myelopathy and frank paralysis. Even less common is the use of PSO for the surgical management of focal congenital kyphosis. We present the case of a child with congenital kyphosis that was managed with a pedicle subtraction osteotomy.
    Methods:  A detailed history and physical examination were performed with careful review of the patient's medical records and x-ray studies. A PSO at T11 was performed along with T9 through L1 instrumented posterolateral fusion.
    Case description:  A 10-year-old girl was evaluated for walking difficulty and a lump on her back. Physical examination revealed a sharp gibbus kyphosis in the lower thoracic spine with tenderness and bilateral back muscle spasms. The patient displayed difficulty with balance lacking a smooth, regular gait rhythm. Clonus and radiculopathy were not present. Plain x-ray of the thoracolumbar spine revealed hyperkyphosis and failure of anterior wall segmentation between T10 and T11 vertebral bodies. Cobb's angle measured 65 degrees. Due to her symptoms and degree of correction required, we elected to perform a PSO at T11 along with T9 to L1 posterolateral instrumentation fusion. No intraoperative complications occurred. There was a significant improvement in her posture and gait.
    Discussion:  A thoracic PSO for congenital kyphosis was safely performed with an excellent outcome. To our knowledge, this is the first PSO procedure performed in Uganda.
    Language English
    Publishing date 2012-12-06
    Publishing country Germany
    Document type Case Reports
    ZDB-ID 2567155-8
    ISSN 1869-4136 ; 1663-7976
    ISSN (online) 1869-4136
    ISSN 1663-7976
    DOI 10.1055/s-0031-1298618
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Hydroxyapatite-coated tapered cementless femoral components in total hip arthroplasty.

    Chambers, Bryan / St Clair, Selvon F / Froimson, Mark I

    The Journal of arthroplasty

    2007  Volume 22, Issue 4 Suppl 1, Page(s) 71–74

    Abstract: Tapered cementless femoral fixation provides a reliable option for routine primary total hip arthroplasty (THA). The use of hydroxyapatite (HA)-coated stems is increasing as a result of mounting evidence that HA may improve the reliability of bone ... ...

    Abstract Tapered cementless femoral fixation provides a reliable option for routine primary total hip arthroplasty (THA). The use of hydroxyapatite (HA)-coated stems is increasing as a result of mounting evidence that HA may improve the reliability of bone osseointegration and improve overall THA outcomes. These trends are based on a growing body of literature that supports both the theoretical and clinical rationale of this approach. There is solid clinical evidence that the combination of tapered geometry with an HA coating increases the likelihood of reliable femoral fixation. A comprehensive review of this literature evaluating the clinical use of cementless femoral components that use an HA coating is presented, and reveals that HA-coated stems have significantly improved proximal femoral fixation with less stress shielding and superior osseous remodeling. Although these advantages have not been shown to significantly increase long-term durability, there is sufficient data to support the routine use of HA-coated, tapered cementless femoral stems in THA.
    MeSH term(s) Arthroplasty, Replacement, Hip ; Coated Materials, Biocompatible/therapeutic use ; Durapatite/therapeutic use ; Femur ; Hip Prosthesis ; Humans ; Prosthesis Design
    Chemical Substances Coated Materials, Biocompatible ; Durapatite (91D9GV0Z28)
    Language English
    Publishing date 2007-06
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 632770-9
    ISSN 0883-5403
    ISSN 0883-5403
    DOI 10.1016/j.arth.2007.01.019
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: T8 spinal cord transection in a 6-year-old child

    St Clair, Selvon F / Silverstein, Michael / Lieberman, Isador

    Evidence-Based Spine-Care Journal

    2012  Volume 3, Issue 03, Page(s) 57–61

    Abstract: Study design: Case report. Objective: To describe a case of spinal cord transection in a 6-year-old child. Background information: Non-missile injury of the spinal cord is not common and its incidence varies according to the country. In addition, to our ... ...

    Abstract Study design: Case report. Objective: To describe a case of spinal cord transection in a 6-year-old child. Background information: Non-missile injury of the spinal cord is not common and its incidence varies according to the country. In addition, to our knowledge, there are no published reports of spinal cord injury (SCI) from a penetrating nail. Here, we report the case of a child who developed complete SCI because of cord transection by a nail. Methods: A detailed history and physical examination were performed along with careful review of the patient’s medical records. In addition, a review of the literature was conducted to assess the incidence and treatment of similar injuries. Case description: A 6-year-old boy was admitted to the hospital after falling from a tree and landing on a nail. His physical examination revealed an emaciated child with multiple decubitus ulcers, lying on his side in bed. Visible was a well-healed posterior puncture wound at the T8 vertebral level. On neurological examination, the patient had 0/5 muscle strength in his lower extremities, symmetrical areflexia, and hypoesthesia below the T8 level. Plain x-ray of the thoracolumbar spine was normal. Magnetic resonance imaging revealed a transected spinal cord at the T8 vertebra, consistent with his nail puncture wound. Discussion: This report describes an unusual case of a complete SCI in a pediatric patient caused by penetrating trauma from a nail. To our knowledge, this is the first case to report on complete SCI due to trauma from a nail.
    Language English
    Publishing date 2012-08-01
    Publisher © AOSpine International
    Publishing place Stuttgart ; New York
    Document type Article
    ISSN 1869-4136 ; 1663-7976
    ISSN (online) 1869-4136
    ISSN 1663-7976
    DOI 10.1055/s-0032-1327811
    Database Thieme publisher's database

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  8. Article ; Online: The difference in spine specimen dual-energy X-ray absorptiometry bone mineral density between in situ and in vitro scans.

    Tan, Juay Seng / Kayanja, Mark M / St Clair, Selvon F

    The spine journal : official journal of the North American Spine Society

    2010  Volume 10, Issue 9, Page(s) 784–788

    Abstract: Background context: Human cadaveric specimens are commonly used to evaluate bone-implant interface strength in osteoporotic spine fixation. Dual-energy X-ray absorptiometry (DXA) scans are usually carried out on explanted spine specimens to measure bone ...

    Abstract Background context: Human cadaveric specimens are commonly used to evaluate bone-implant interface strength in osteoporotic spine fixation. Dual-energy X-ray absorptiometry (DXA) scans are usually carried out on explanted spine specimens to measure bone mineral density (BMD) before in vitro biomechanical studies are carried out.
    Purpose: The purposes of this study were to verify and quantify the difference in DXA BMD between unexplanted (in situ) and explanted (in vitro) scans and to develop and validate a correction factor (CF) between in vitro and in situ DXA BMD.
    Study design: This is a retrospective analysis of past DXA scans of explanted specimens and a repeated measure scan rescan study of in situ and in vitro spine specimens.
    Methods: Dual-energy X-ray absorptiometry scans were previously carried out on 106 male and 83 female lumbar specimens. Using multiple regressions, the correlation functions between Z score, BMD, and age were determined for male and female groups. The CF was developed based on difference in BMD between mean in vitro and population data. Next, in situ DXA scans were carried out on the lumbar spine of four full human cadavers, and subsequently, in vitro scans were repeated after explantation. The CF was applied to these in vitro scan data and the resulting corrected BMD compared with in situ scan values.
    Results: The specimens had significantly lower Z score than population mean. The mean Z score was -0.7+/-1.4 (p<.001) for male and -0.3+/-1.3 (p=.03) for female specimens. The difference between in situ and in vitro scans was quantified to be 0.06 g/cm(2) for male specimens and to be a function of age (6.80 Age(-0.5)-3.76 Age(-0.365)) for female specimens. In vitro BMD was 96+/-11% of in situ BMD and was significantly different (p=.04). Corrected BMD after application of CF was 97+/-11% of in situ BMD and was not significantly different (p=.13).
    Conclusions: In vitro BMD scan on explanted specimens measured lower DXA values than in situ BMD scans on full cadavers. A CF when used resulted in more accurate measure of the in situ BMD.
    MeSH term(s) Absorptiometry, Photon ; Aged ; Bone Density ; Cadaver ; Female ; Humans ; Lumbar Vertebrae/diagnostic imaging ; Male ; Middle Aged ; Spine/diagnostic imaging
    Language English
    Publishing date 2010-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2037072-6
    ISSN 1878-1632 ; 1529-9430
    ISSN (online) 1878-1632
    ISSN 1529-9430
    DOI 10.1016/j.spinee.2010.02.016
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: The dual specificity phosphatase Cdc25C is a direct target for transcriptional repression by the tumor suppressor p53.

    St Clair, Selvon / Manfredi, James J

    Cell cycle (Georgetown, Tex.)

    2006  Volume 5, Issue 7, Page(s) 709–713

    Abstract: The cdc25C gene has been shown to be a novel target for transcriptional downregulation by p53. Two independent mechanisms contribute to the p53-dependent repression of the cdc25C gene. First, an element in the cdc25C promoter consisting of a binding site ...

    Abstract The cdc25C gene has been shown to be a novel target for transcriptional downregulation by p53. Two independent mechanisms contribute to the p53-dependent repression of the cdc25C gene. First, an element in the cdc25C promoter consisting of a binding site for p53 plus an adjacent 8 base pairs confers p53-dependent repression. Mutation of either the p53 binding site or the adjacent 8 bp sequence abolishes this effect. The element conferring p53-dependent repression also contains a binding site for the transcription factor Sp1 and a mutant p53 protein that retains the ability to interact with the p53-binding site is defective in mediating repression. Second, a minimal promoter lacking the p53 binding site but containing a previously characterized CDE/CHR element is also repressed by p53. This repression is abrogated when a 5 bp mutation is introduced in the CHR sequence. These results support a model for p53 downregulating cdc25C expression, in part, by direct binding to a promoter element that is likely to require cooperation with an additional cellular factor.
    MeSH term(s) Animals ; Cell Cycle Proteins/genetics ; Cell Cycle Proteins/metabolism ; Humans ; Models, Genetic ; Promoter Regions, Genetic/genetics ; Repressor Proteins/metabolism ; Transcription, Genetic/genetics ; Tumor Suppressor Protein p53/metabolism ; cdc25 Phosphatases/genetics ; cdc25 Phosphatases/metabolism
    Chemical Substances Cell Cycle Proteins ; Repressor Proteins ; Tumor Suppressor Protein p53 ; CDC25C protein, human (EC 3.1.3.48) ; cdc25 Phosphatases (EC 3.1.3.48)
    Language English
    Publishing date 2006-04-01
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 2146183-1
    ISSN 1551-4005 ; 1538-4101 ; 1554-8627
    ISSN (online) 1551-4005
    ISSN 1538-4101 ; 1554-8627
    DOI 10.4161/cc.5.7.2628
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Posterolateral spinal cord decompression in patients with metastasis: an endoscopic assisted approach.

    St Clair, Selvon F / McLain, Robert F

    Surgical technology international

    2006  Volume 15, Page(s) 257–263

    Abstract: Spinal tumors that are radioresistant or cause bony compression of the spinal cord often require surgical decompression to protect or restore neurological function. Metastatic lesions and primary tumors such as multiple myeloma usually arise in the ... ...

    Abstract Spinal tumors that are radioresistant or cause bony compression of the spinal cord often require surgical decompression to protect or restore neurological function. Metastatic lesions and primary tumors such as multiple myeloma usually arise in the vertebral body, which can collapse and become unstable, and can compress the anterior columns of the cord. Laminectomy is often ineffective in these patients, and direct anterior decompression through thoracotomy is the widely-accepted solution to the neurological problem. The anterior surgical approach is particularly challenging in the upper thoracic spine. Patients with limited pulmonary reserve due to pneumonectomy or pulmonary metastasis might not tolerate the loss of lung capacity necessitated by either thoracotomy or thoracoscopy. Because posterior instrumentation is usually needed to provide stability following corpectomy and spinal cord decompression, posterolateral approaches to spinal cord decompression have gained favor in recent years. Posterolateral decompression offers advantages over the combined anterior and posterior approach, reducing operative time, morbidity, and hospital stay. Drawbacks to traditional posterolateral decompressions include poor visualization of the tumor immediately anterior to the spinal cord and the need to manipulate the spinal cord to completely remove a tumor adherent to the dura. Endoscopically assisted posterolateral decompression allows decompression of the anterior surface of the spinal cord, the point of pressure in most circumstances. Endoscopic video assistance facilitates vertebrectomy, cord decompression, and anterior reconstruction, all performed through the same posterior incision. Endoscopic assisted spinal cord decompression dramatically reduces morbidity, ICU requirements, and inpatient hospitalization and has proven useful for a variety of metastatic tumors at every level of the spinal column.
    MeSH term(s) Adolescent ; Aged ; Back Pain/etiology ; Back Pain/prevention & control ; Bone Neoplasms/complications ; Bone Neoplasms/pathology ; Bone Neoplasms/secondary ; Bone Neoplasms/surgery ; Decompression, Surgical/methods ; Female ; Humans ; Laminectomy/methods ; Male ; Middle Aged ; Spinal Cord Compression/etiology ; Spinal Cord Compression/pathology ; Spinal Cord Compression/surgery ; Treatment Outcome ; Video-Assisted Surgery/methods
    Language English
    Publishing date 2006
    Publishing country United States
    Document type Case Reports ; Journal Article ; Review
    ZDB-ID 1225512-9
    ISSN 1090-3941
    ISSN 1090-3941
    Database MEDical Literature Analysis and Retrieval System OnLINE

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