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1.
Front Rehabil Sci ; 4: 1205456, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37378049

RESUMO

Introduction: The paralysis that occurs after a spinal cord injury, particularly during the early stages of post-lesion recovery (∼6 weeks), appears to be attributable to the inability to activate motor pools well beyond their motor threshold. In the later stages of recovery, however, the inability to perform a motor task effectively can be attributed to abnormal activation patterns among motor pools, resulting in poor coordination. Method: We have tested this hypothesis on four adult male Rhesus monkeys (Macaca mulatta), ages 6-10 years, by recording the EMG activity levels and patterns of multiple proximal and distal muscles controlling the upper limb of the Rhesus when performing three tasks requiring different levels of skill before and up to 24 weeks after a lateral hemisection at C7. During the recovery period the animals were provided routine daily care, including access to a large exercise cage (5' × 7' × 10') and tested every 3-4 weeks for each of the three motor tasks. Results: At approximately 6-8 weeks the animals were able to begin to step on a treadmill, perform a spring-loaded task with the upper limb, and reaching, grasping, and eating a grape placed on a vertical stick. The predominant changes that occurred, beginning at ∼6-8 weeks of the recovery of these tasks was an elevated level of activation of most motor pools well beyond the pre-lesion level. Discussion: As the chronic phase progressed there was a slight reduction in the EMG burst amplitudes of some muscles and less incidence of co-contraction of agonists and antagonists, probably contributing to an improved ability to selectively activate motor pools in a more effective temporal pattern. Relative to pre-lesion, however, the EMG patterns even at the initial stages of recovery of successfully performing the different motor tasks, the level of activity of most muscle remained higher. Perhaps the most important concept that emerges from these data is the large combinations of adaptive strategies in the relative level of recruitment and the timing of the peak levels of activation of different motor pools can progressively provide different stages to regain a motor skill.

2.
J Equine Vet Sci ; 126: 104502, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37120116

RESUMO

A 21-year-old Quarter Horse mare presented with a chronic, progressively worsening left pelvic limb lameness of 3 weeks duration. The initial examination identified a consistent lameness at a walk. Neurological examination showed sensory and gait abnormalities consistent with left femoral nerve dysfunction. The horse minimally advanced the leg cranially and had a shortened stride length at the walk. During the stance phase, the heels of the left hind foot did not contact the ground and the horse quickly took weight off of the limb. Diagnostic imaging (ultrasound and nuclear scintigraphy) examinations did not reveal a cause. Severe lymphocytosis was identified on complete blood cell count (69,600 cells /uL; reference range: 1,500-4,000 cells/uL), suggestive of lymphoma. Postmortem examination revealed focal swelling of the left femoral nerve. Multiple masses were found in the stomach, large colon, adrenal gland, mesentery, heart, and meninges. The entire left pelvic limb was dissected and did not reveal other causes of the gait deficit. Histologic evaluation of the left femoral nerve revealed disseminated intermediate cell size B cell lymphoma, with an immunophenotype suggestive of plasmacytoid differentiation. These lymphocytes infiltrated the femoral nerve at the location of the focal nerve swelling, in addition to other peripheral nerves. This case highlights a horse with an atypical diagnosis of femoral nerve paresis caused by direct neoplastic lymphocyte infiltration, deriving from disseminated B cell lymphoma with plasmacytoid differentiation (neurolymphomatosis). Though rare, disseminated lymphoma with direct nerve infiltration should be considered in horses with peripheral neuropathies.


Assuntos
Doenças dos Cavalos , Linfoma de Células B , Linfoma , Doenças do Sistema Nervoso Periférico , Cavalos , Animais , Feminino , Doenças do Sistema Nervoso Periférico/veterinária , Nervo Femoral/patologia , Coxeadura Animal/diagnóstico , Coxeadura Animal/etiologia , Linfoma de Células B/complicações , Linfoma de Células B/diagnóstico , Linfoma de Células B/veterinária , Linfoma/patologia , Linfoma/veterinária , Doenças dos Cavalos/diagnóstico , Doenças dos Cavalos/patologia
3.
Neuron ; 110(18): 2970-2983.e4, 2022 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-35917818

RESUMO

We used viral intersectional tools to map the entire projectome of corticospinal neurons associated with fine distal forelimb control in Fischer 344 rats and rhesus macaques. In rats, we found an extraordinarily diverse set of collateral projections from corticospinal neurons to 23 different brain and spinal regions. Remarkably, the vast weighting of this "motor" projection was to sensory systems in both the brain and spinal cord, confirmed by optogenetic and transsynaptic viral intersectional tools. In contrast, rhesus macaques exhibited far heavier and narrower weighting of corticospinal outputs toward spinal and brainstem motor systems. Thus, corticospinal systems in macaques primarily constitute a final output system for fine motor control, whereas this projection in rats exerts a multi-modal integrative role that accesses far broader CNS regions. Unique structural-functional correlations can be achieved by mapping and quantifying a single neuronal system's total axonal output and its relative weighting across CNS targets.


Assuntos
Córtex Motor , Tratos Piramidais , Animais , Axônios/fisiologia , Mapeamento Encefálico , Macaca mulatta , Córtex Motor/fisiologia , Tratos Piramidais/fisiologia , Ratos , Medula Espinal/fisiologia
4.
Vet Clin North Am Equine Pract ; 38(2): 363-377, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35810150

RESUMO

Mechanisms of traumatic nervous system injury to a degree are similar, but differences exist in etiology, pathophysiology, and treatment of brain, spinal cord, and peripheral nerve injury. The most common clinical abnormalities seen in the horse are abnormal level of consciousness, abnormal behavior, seizures, cranial nerve deficits, vestibular disease, tetra- and paraparesis or paraplegia, cauda equina syndrome, specific gait deficits, and muscle atrophy. Treatments are directed toward reducing inflammation and swelling, halting secondary injury, and promoting mechanisms of neuroregeneration and plasticity. Prognosis depends on the severity of primary injury and the neuroanatomic location and extent of nervous tissue damage.


Assuntos
Doenças dos Cavalos , Traumatismos da Medula Espinal , Animais , Cavalos , Traumatismos da Medula Espinal/veterinária
5.
Equine Vet J ; 54(2): 347-358, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33844334

RESUMO

BACKGROUND: Further development of surgical techniques for equine cervical stabilisation is necessary to make the procedure less technically demanding, reduce complications and improve outcomes. OBJECTIVE: To describe clinical outcomes and owner reports in horses undergoing placement of an interbody fusion device and polyaxial pedicle screw and rod construct for cervical vertebral fusion in horses with cervical vertebral compressive myelopathy. STUDY DESIGN: Retrospective case series. METHODS: Data were retrieved from medical records of 10 horses undergoing cervical vertebral fusion (2015-2019). Records were evaluated for signalment, duration of clinical signs, number and location of compression sites, grade of ataxia, duration of hospitalisation and complications. Long-term follow-up was obtained through clinical re-evaluation, postoperative radiographs and owner contact. RESULTS: Breeds were mixed. Median age was 24 (range 12-168) months. There were 2/10 mares, 4/10 geldings and 4/10 stallions. Preoperative grade of ataxia ranged from 1-3/5. Fusion was performed at one (n = 3) or two (n = 7) sites. Two horses were euthanised within the first year. In 6 of 8 horses with ≥1-year follow-up, ataxia improved by 1-3 grades, with an average improvement of 1.25 grades. In four horses, ataxia improved to grade 0-1. In two horses the gait was unaffected, but neck comfort improved. Complications included seroma formation (n = 9), pain (n = 5), fever (n = 4), upper respiratory tract obstruction (n = 2), azotemia (n = 2), screw breakage (n = 2), progression of neurological signs (n = 1), Horner's Syndrome (n = 1), dysphagia (n = 1), hives (n = 1), implant infection (n = 1) and nondisplaced fracture (n = 1). MAIN LIMITATIONS: Small case series, heterogeneous patient population. CONCLUSIONS: This technique resulted in ≥1 grade gait improvement in 6/10 cases operated and 6/8 cases for which ≥1-year follow-up was available, similar to other methods. Fatal complications related to implant placement did not occur. This technique may represent a safer alternative to current techniques of ventral interbody fusion with similar outcomes.


Assuntos
Parafusos Pediculares , Fusão Vertebral , Animais , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Feminino , Cavalos , Masculino , Radiografia , Estudos Retrospectivos , Fusão Vertebral/veterinária , Resultado do Tratamento
6.
Front Vet Sci ; 8: 734218, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34957274

RESUMO

Introduction: Dangerous behavior is considered an undesired trait, often attributed to poor training or bad-tempered horses. Unfortunately, horses with progressive signs of dangerous behavior are often euthanized due to concerns for rider safety and limitations in performance. However, this dangerous behavior may actually originate from chronic axial skeleton pain. This case series describes the medical histories and clinical presentations of horses presented for performance limitations and dangerous behavior judged to be related to intractable axial skeleton pain. Material and Methods: Fourteen horses that developed severe performance limitations resulting in euthanasia were included. A complete spinal examination and behavioral responses, gait and neurologic evaluations, diagnostic imaging, gross pathologic and histopathologic examinations of the axial skeleton were performed on all horses. A tentative diagnosis of the affected spinal region was formulated using medical records, owner and trainer complaints, and antemortem examination findings. The selected spinal regions were further examined with gross and histopathologic evaluations of the associated osseous, soft tissue and neural tissues. Results: Ten horses showed severe behavioral responses during the myofascial and mobilization examinations. Based on an aggregate evaluation, the cervicothoracic and lumbosacral regions were the most common regions believed to be the primary area of concern. All horses had moderate to severe ganglionitis present at multiple vertebral levels. Subdural and epidural hemorrhage or hematomas were a common finding (71%) in the cervicothoracic and lumbosacral regions. Discussion: In this case series, neuropathic (i.e., structural) pain was judged to be the underlying cause of dangerous behavior. The dorsal root ganglia (DRG) serve an important role in relaying peripheral sensory information to the central nervous system and ganglionitis has been associated with neuropathic pain syndromes. This series highlights the need for more in-depth understanding of pain behavior and its clinical presentation and progression in chronic or severely affected horses. Limitations of the study are the lack of age-matched control DRG and the incomplete collection of DRG from every vertebral level of interest.

7.
Animals (Basel) ; 11(2)2021 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-33562089

RESUMO

Interest in the cervical spine as a cause of pain or dysfunction is increasingly becoming the focus of many equine practitioners. Many affected horses are presented for poor performance, while others will present with dramatic, sometimes dangerous behavior. Understanding and distinguishing the different types of neck pain is a starting point to comprehending how the clinical presentations can vary so greatly. There are many steps needed to systematically evaluate the various tissues of the cervical spine to determine which components are contributing to cervical pain and dysfunction. Osseous structures, soft tissues and the central and the peripheral nervous system may all play a role in these various clinical presentations. After completing the clinical evaluation, several imaging modalities may be implemented to help determine the underlying pathologic processes. There are multiple treatment options available and each must be carefully chosen for an individual horse. Provided is a synopsis of the current knowledge as to different disease processes that can result in cervical pain and dysfunction, diagnostic approaches and treatment strategies. Improving the knowledge in these areas will ideally help to return horses to a state of well-being that can be maintained over time and through the rigors of their job or athletic endeavors.

8.
Front Vet Sci ; 7: 583342, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33263015

RESUMO

Spinal cord injury in companion dogs can lead to urinary and fecal incontinence or retention, depending on the severity, and localization of the lesion along the canine nervous system. The bladder and gastrointestinal dysfunction caused by lesions of the autonomic system can be difficult to recognize, interpret and are easily overlooked. Nevertheless, it is crucial to maintain a high degree of awareness of the impact of micturition and defecation disturbances on the animal's condition, welfare and on the owner. The management of these disabilities is all the more challenging that the autonomic nervous system physiology is a complex topic. In this review, we propose to briefly remind the reader the physiology of micturition and defecation in dogs. We then present the bladder and gastrointestinal clinical signs associated with sacral lesions (i.e., the L7-S3 spinal cord segments and nerves) and supra-sacral lesions (i.e., cranial to the L7 spinal cord segment), largely in the context of intervertebral disc herniation. We summarize what is known about the natural recovery of urinary and fecal continence in dogs after spinal cord injury. In particular we review the incidence of urinary tract infection after injury. We finally explore the past and recent literature describing management of urinary and fecal dysfunction in the acute and chronic phase of spinal cord injury. This comprises medical therapies but importantly a number of surgical options, some known for decades such as sacral nerve stimulation, that might spark some interest in the field of spinal cord injury in companion dogs.

9.
J Vet Diagn Invest ; 31(5): 688-695, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31347464

RESUMO

Detection of equine acute kidney injury (AKI) is hindered by limited markers of early renal damage in horses. N-acetyl-ß-D-glucosaminidase (NAG), a lysosomal enzyme in renal tubular epithelium released into urine during tubular insult, has shown promise for early identification of AKI in humans and other species. We validated an assay for NAG in equine urine and measured urinary NAG in 7 azotemic and 7 non-azotemic client-owned adult horses. The enzymatic NAG assay was validated using within- and between-run coefficients of variation (CVs), recovery following standard addition, and linearity of dilution. Intra- and inter-run CVs (21% and 3.2%, respectively), average recovery following standard addition (99-109%), and linearity under serial dilution (R2 = 0.997) were satisfactory. Urine NAG index was significantly correlated with urinary fractional excretion of sodium (FENa; ρ = 0.76, p < 0.001) and plasma creatinine (ρ = 0.74, p = 0.001). Median urine NAG indices were higher in azotemic horses (p = 0.006), in horses with increased urinary FENa (p = 0.006), and in horses with increased urine gamma-glutamyl transferase index (p = 0.032). Urine NAG can be measured in horses and shows positive correlation with 2 current renal biomarkers. Additional work is needed to establish normal equine reference intervals and characterize the increase of urine NAG index in horses in relation to tubular injury.


Assuntos
Acetilglucosaminidase/urina , Injúria Renal Aguda/veterinária , Doenças dos Cavalos/diagnóstico , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/urina , Animais , Biomarcadores/urina , Creatinina/sangue , Feminino , Doenças dos Cavalos/urina , Cavalos , Humanos , Masculino , Sódio/urina , gama-Glutamiltransferase/urina
10.
Nat Neurosci ; 22(8): 1269-1275, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31235933

RESUMO

Inhibitory extracellular matrices form around mature neurons as perineuronal nets containing chondroitin sulfate proteoglycans that limit axonal sprouting after CNS injury. The enzyme chondroitinase (Chase) degrades inhibitory chondroitin sulfate proteoglycans and improves axonal sprouting and functional recovery after spinal cord injury in rodents. We evaluated the effects of Chase in rhesus monkeys that had undergone C7 spinal cord hemisection. Four weeks after hemisection, we administered multiple intraparenchymal Chase injections below the lesion, targeting spinal cord circuits that control hand function. Hand function improved significantly in Chase-treated monkeys relative to vehicle-injected controls. Moreover, Chase significantly increased corticospinal axon growth and the number of synapses formed by corticospinal terminals in gray matter caudal to the lesion. No detrimental effects were detected. This approach appears to merit clinical translation in spinal cord injury.


Assuntos
Condroitinases e Condroitina Liases/uso terapêutico , Traumatismos da Medula Espinal/tratamento farmacológico , Animais , Axônios/patologia , Condroitinases e Condroitina Liases/administração & dosagem , Condroitinases e Condroitina Liases/efeitos adversos , Substância Cinzenta/patologia , Mãos/inervação , Mãos/fisiopatologia , Injeções Intralesionais , Macaca mulatta , Masculino , Microglia/patologia , Neurônios Motores/patologia , Desempenho Psicomotor , Tratos Piramidais/patologia , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal/fisiopatologia , Suínos , Sinapses/patologia , Resultado do Tratamento
11.
Spinal Cord ; 56(7): 656-665, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29795173

RESUMO

STUDY DESIGN: Prospective cross-sectional cohort study. OBJECTIVES: The canine spontaneous model of spinal cord injury (SCI) is as an important pre-clinical platform as it recapitulates key facets of human injury in a naturally occurring context. The establishment of an observational canine SCI registry constitutes a key step in performing epidemiologic studies and assessing the impact of therapeutic strategies to enhance translational research. Further, accumulating information on dogs with SCI may contribute to current "big data" approaches to enhance understanding of the disease using heterogeneous multi-institutional, multi-species datasets from both pre-clinical and human studies. SETTING: Multiple veterinary academic institutions across the United States and Europe. METHODS: Common data elements recommended for experimental and human SCI studies were reviewed and adapted for use in a web-based registry, to which all dogs presenting to member veterinary tertiary care facilities were prospectively entered over ~1 year. RESULTS: Analysis of data accumulated during the first year of the registry suggests that 16% of dogs with SCI present with severe, sensorimotor-complete injury and that 15% of cases are seen by a tertiary care facility within 8 h of injury. Similar to the human SCI population, 34% were either overweight or obese. CONCLUSIONS: Severity of injury and timing of presentation suggests that neuroprotective studies using the canine clinical model could be conducted efficiently using a multi-institutional approach. Additionally, pet dogs with SCI experience similar comorbidities to people with SCI, in particular obesity, and could serve as an important model to evaluate the effects of this condition.


Assuntos
Modelos Animais de Doenças , Disseminação de Informação , Cooperação Internacional , Sistema de Registros , Traumatismos da Medula Espinal , Pesquisa Translacional Biomédica , Animais , Estudos de Coortes , Estudos Cross-Over , Cães , Europa (Continente) , Feminino , Masculino , Traumatismos da Medula Espinal/epidemiologia , Traumatismos da Medula Espinal/terapia , Traumatismos da Medula Espinal/veterinária , Pesquisa Translacional Biomédica/métodos , Estados Unidos
12.
Nat Med ; 24(4): 484-490, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29480894

RESUMO

We grafted human spinal cord-derived neural progenitor cells (NPCs) into sites of cervical spinal cord injury in rhesus monkeys (Macaca mulatta). Under three-drug immunosuppression, grafts survived at least 9 months postinjury and expressed both neuronal and glial markers. Monkey axons regenerated into grafts and formed synapses. Hundreds of thousands of human axons extended out from grafts through monkey white matter and synapsed in distal gray matter. Grafts gradually matured over 9 months and improved forelimb function beginning several months after grafting. These findings in a 'preclinical trial' support translation of NPC graft therapy to humans with the objective of reconstituting both a neuronal and glial milieu in the site of spinal cord injury.


Assuntos
Regeneração Nervosa , Células-Tronco Neurais/transplante , Medula Espinal/fisiopatologia , Animais , Axônios/metabolismo , Diferenciação Celular , Movimento Celular , Sobrevivência Celular , Humanos , Macaca mulatta , Imageamento por Ressonância Magnética , Masculino , Células-Tronco Neurais/citologia , Medula Espinal/patologia , Medula Espinal/ultraestrutura , Resultado do Tratamento
13.
J Biomed Mater Res B Appl Biomater ; 106(2): 501-511, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28188976

RESUMO

Chitosan is attractive as a substrate for stem cell expansion because it improves stemness through formation of spheroids. Hypoxia has also been proposed as a strategy to enhance stemness and survival of stem cells after in vivo implantation. This study was therefore designed to evaluate the influence of hypoxia on chitosan-induced behavior of stem cells. Umbilical cord matrix-derived stem cells were cultured on chitosan film or standard plate under normoxia and hypoxia, for 3 and 7 days. Based on immunophenotyping, chitosan strongly suppresses the expression of CD90 and CD105 cell surface markers, changes partially reversed by combined exposure to hypoxia. Hypoxia generally increased the volume and number of spheroids formed on chitosan, but the cellularity of cultures on chitosan films remained lower than that of standard plates. After 7 days of culture, the expression of stemness related genes (Oct4, Sox2, and Nanog) was best stimulated by combined exposure to chitosan and hypoxia. Based on our results, conditioning stem cells for 7 days on chitosan films under hypoxic conditions is recommended to enhance the stemness of stem cells, and minimize cell loss due to lack of attachment on chitosan. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 501-511, 2018.


Assuntos
Quitosana/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Oxigênio/metabolismo , Polímeros/farmacologia , Cordão Umbilical/citologia , Anaerobiose , Animais , Diferenciação Celular , Proliferação de Células , Quitosana/química , Endoglina/metabolismo , Feminino , Cavalos , Humanos , Células-Tronco Mesenquimais/química , Polímeros/química , Cultura Primária de Células , Esferoides Celulares/química , Esferoides Celulares/efeitos dos fármacos , Antígenos Thy-1/metabolismo
14.
J Neurotrauma ; 34(12): 2007-2018, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28230415

RESUMO

Translation of therapeutic interventions for spinal cord injury (SCI) from laboratory to clinic has been historically challenging, highlighting the need for robust models of injury that more closely mirror the human condition. The high prevalence of acute, naturally occurring SCI in pet dogs provides a unique opportunity to evaluate expeditiously promising interventions in a population of animals that receive diagnoses and treatment clinically in a manner similar to persons with SCI, while adhering to National Institutes of Health guidelines for scientific rigor and transparent reporting. In addition, pet dogs with chronic paralysis are often maintained long-term by their owners, offering a similarly unique population for study of chronic SCI. Despite this, only a small number of studies have used the clinical dog model of SCI. The Canine Spinal Cord Injury Consortium (CANSORT-SCI) was recently established by a group of veterinarians and basic science researchers to promote the value of the canine clinical model of SCI. The CANSORT-SCI group held an inaugural meeting November 20 and 21, 2015 to evaluate opportunities and challenges to the use of pet dogs in SCI research. Key challenges identified included lack of familiarity with the model among nonveterinary scientists and questions about how and where in the translational process the canine clinical model would be most valuable. In light of these, we review the natural history, outcome, and available assessment tools associated with canine clinical SCI with emphasis on their relevance to human SCI and the translational process.


Assuntos
Modelos Animais de Doenças , Cães , Animais de Estimação , Traumatismos da Medula Espinal , Pesquisa Translacional Biomédica , Animais
15.
Can Vet J ; 57(5): 492-6, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27152035

RESUMO

A 20-year-old gelding was diagnosed with peritonitis and severe reactive mesothelial hyperplasia. Exploratory laparotomy findings were suggestive of a neoplastic etiology; however, additional diagnostics ruled this out and the horse made a full recovery. This report demonstrates the difficulty and value of differentiating between reactive and neoplastic mesothelial processes.


Hyperplasie mésothéliale réactive associée à une péritonite aiguë chez un cheval Quarter horse âgé de 20 ans. Une péritonite et l'hyperplasie mésothéliale réactive grave ont été diagnostiquées chez un hongre âgé de 20 ans. Les résultats d'une laparatomie exploratoire ont suggéré une étiologie néoplasique. Cependant, des diagnostics additionnels ont éliminé cette possibilité et le cheval s'est complètement rétabli. Ce rapport démontre la difficulté et la pertinence de différencier entre les processus mésothéliaux réactif et néoplasique.(Traduit par Isabelle Vallières).


Assuntos
Doenças dos Cavalos/diagnóstico , Hiperplasia/veterinária , Peritonite/veterinária , Animais , Diagnóstico Diferencial , Epitélio/patologia , Doenças dos Cavalos/etiologia , Cavalos , Hiperplasia/diagnóstico , Hiperplasia/etiologia , Hiperplasia/patologia , Masculino , Peritonite/complicações , Peritonite/diagnóstico
16.
J Neurotrauma ; 33(5): 439-59, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26788611

RESUMO

The development of a non-human primate (NHP) model of spinal cord injury (SCI) based on mechanical and computational modeling is described. We scaled up from a rodent model to a larger primate model using a highly controllable, friction-free, electronically-driven actuator to generate unilateral C6-C7 spinal cord injuries. Graded contusion lesions with varying degrees of functional recovery, depending upon pre-set impact parameters, were produced in nine NHPs. Protocols and pre-operative magnetic resonance imaging (MRI) were used to optimize the predictability of outcomes by matching impact protocols to the size of each animal's spinal canal, cord, and cerebrospinal fluid space. Post-operative MRI confirmed lesion placement and provided information on lesion volume and spread for comparison with histological measures. We evaluated the relationships between impact parameters, lesion measures, and behavioral outcomes, and confirmed that these relationships were consistent with our previous studies in the rat. In addition to providing multiple univariate outcome measures, we also developed an integrated outcome metric describing the multivariate cervical SCI syndrome. Impacts at the higher ranges of peak force produced highly lateralized and enduring deficits in multiple measures of forelimb and hand function, while lower energy impacts produced early weakness followed by substantial recovery but enduring deficits in fine digital control (e.g., pincer grasp). This model provides a clinically relevant system in which to evaluate the safety and, potentially, the efficacy of candidate translational therapies.


Assuntos
Contusões/patologia , Modelos Animais de Doenças , Traumatismos da Medula Espinal/patologia , Animais , Vértebras Cervicais , Contusões/cirurgia , Macaca mulatta , Masculino , Traumatismos da Medula Espinal/cirurgia
17.
J Neurotrauma ; 33(10): 929-42, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-26483094

RESUMO

Alterations in magnetic resonance imaging (MRI)-derived measurements of water diffusion parallel (D∥) and perpendicular (D⊥) to white matter tracts have been specifically attributed to pathology of axons and myelin, respectively. We test the hypothesis that directional diffusion measurements can distinguish between axon-sparing chemical demyelination and severe contusion spinal cord white matter injury. Adult rats received either unilateral ethidium bromide (EB) microinjections (chemical demyelination) into the lateral funiculus of the spinal cord at C5 or were subjected to unilateral severe contusion spinal cord injury (SCI). Diffusion MRI metrics in the lateral funiculus were analyzed at early and late time-points following injury and correlated with histology. Early EB-demyelination resulted in a significant elevation in D⊥ and significant reduction in D∥ at the injury epicenter, with histological evidence of uniform axon preservation. Alterations in D⊥ and D∥ at the epicenter of early EB-demyelination were not significantly different from those observed with severe contusion at the epicenter, where histology demonstrated severe combined axonal and myelin injury. Diffusion abnormalities away from the injury epicenter were seen with contusion injury, but not with EB-demyelination. Chronic EB lesions underwent endogenous remyelination with normalization of diffusion metrics, whereas chronic contusion resulted in persistently altered diffusivities. In the early setting, directional diffusion measurements at the injury epicenter associated with chemical demyelination are indistinguishable from those seen with severe contusive SCI, despite dramatic pathologic differences between injury models. Caution is advised in interpretation of diffusion metrics with respect to specific white matter structural alterations. Diffusion analysis should not be limited to the epicenter of focal spinal lesions as alterations marginal to the epicenter are useful for assessing the nature of focal white matter injury.


Assuntos
Doenças Desmielinizantes , Imagem de Difusão por Ressonância Magnética/normas , Traumatismos da Medula Espinal/diagnóstico por imagem , Traumatismos da Medula Espinal/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Animais , Vértebras Cervicais , Doenças Desmielinizantes/induzido quimicamente , Doenças Desmielinizantes/diagnóstico por imagem , Doenças Desmielinizantes/patologia , Modelos Animais de Doenças , Feminino , Ratos , Ratos Sprague-Dawley
18.
Brain Res ; 1619: 124-38, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-25451131

RESUMO

Recent preclinical advances highlight the therapeutic potential of treatments aimed at boosting regeneration and plasticity of spinal circuitry damaged by spinal cord injury (SCI). With several promising candidates being considered for translation into clinical trials, the SCI community has called for a non-human primate model as a crucial validation step to test efficacy and validity of these therapies prior to human testing. The present paper reviews the previous and ongoing efforts of the California Spinal Cord Consortium (CSCC), a multidisciplinary team of experts from 5 University of California medical and research centers, to develop this crucial translational SCI model. We focus on the growing volumes of high resolution data collected by the CSCC, and our efforts to develop a biomedical informatics framework aimed at leveraging multidimensional data to monitor plasticity and repair targeting recovery of hand and arm function. Although the main focus of many researchers is the restoration of voluntary motor control, we also describe our ongoing efforts to add assessments of sensory function, including pain, vital signs during surgery, and recovery of bladder and bowel function. By pooling our multidimensional data resources and building a unified database infrastructure for this clinically relevant translational model of SCI, we are now in a unique position to test promising therapeutic strategies' efficacy on the entire syndrome of SCI. We review analyses highlighting the intersection between motor, sensory, autonomic and pathological contributions to the overall restoration of function. This article is part of a Special Issue entitled SI: Spinal cord injury.


Assuntos
Modelos Animais de Doenças , Informática Médica , Plasticidade Neuronal , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal/terapia , Regeneração da Medula Espinal , Animais , Humanos , Macaca mulatta , Atividade Motora , Traumatismos da Medula Espinal/fisiopatologia , Pesquisa Translacional Biomédica , Resultado do Tratamento
19.
J Neurotrauma ; 31(21): 1789-99, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25077610

RESUMO

Efforts to understand spinal cord injury (SCI) and other complex neurotrauma disorders at the pre-clinical level have shown progress in recent years. However, successful translation of basic research into clinical practice has been slow, partly because of the large, heterogeneous data sets involved. In this sense, translational neurological research represents a "big data" problem. In an effort to expedite translation of pre-clinical knowledge into standards of patient care for SCI, we describe the development of a novel database for translational neurotrauma research known as Visualized Syndromic Information and Outcomes for Neurotrauma-SCI (VISION-SCI). We present demographics, descriptive statistics, and translational syndromic outcomes derived from our ongoing efforts to build a multi-center, multi-species pre-clinical database for SCI models. We leveraged archived surgical records, postoperative care logs, behavioral outcome measures, and histopathology from approximately 3000 mice, rats, and monkeys from pre-clinical SCI studies published between 1993 and 2013. The majority of animals in the database have measures collected for health monitoring, such as weight loss/gain, heart rate, blood pressure, postoperative monitoring of bladder function and drug/fluid administration, behavioral outcome measures of locomotion, and tissue sparing postmortem. Attempts to align these variables with currently accepted common data elements highlighted the need for more translational outcomes to be identified as clinical endpoints for therapeutic testing. Last, we use syndromic analysis to identify conserved biological mechanisms of recovery after cervical SCI between rats and monkeys that will allow for more-efficient testing of therapeutics that will need to be translated toward future clinical trials.


Assuntos
Bases de Dados Factuais , Traumatismos da Medula Espinal/fisiopatologia , Pesquisa Translacional Biomédica , Animais , Biologia Computacional , Haplorrinos , Camundongos , Modelos Animais , Ratos
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