RESUMO
INTRODUCTION: Seizures and abnormal periodic or rhythmic patterns are observed on continuous electroencephalography monitoring (cEEG) in up to half of patients hospitalized with moderate to severe traumatic brain injury (TBI). We aimed to determine the impact of seizures and abnormal periodic or rhythmic patterns on cognitive outcome 3 months following moderate to severe TBI. METHODS: This was a post hoc analysis of the multicenter randomized controlled phase 2 INTREPID2566 clinical trial conducted from 2010 to 2016 across 20 United States Level I trauma centers. Patients with nonpenetrating TBI and postresuscitation Glasgow Coma Scale scores 4-12 were included. Bedside cEEG was initiated per protocol on admission to intensive care, and the burden of ictal-interictal continuum (IIC) patterns, including seizures, was quantified. A summary global cognition score at 3 months following injury was used as the primary outcome. RESULTS: 142 patients (age mean + / - standard deviation 32 + / - 13 years; 131 [92%] men) survived with a mean global cognition score of 81 + / - 15; nearly one third were considered to have poor functional outcome. 89 of 142 (63%) patients underwent cEEG, of whom 13 of 89 (15%) had severe IIC patterns. The quantitative burden of IIC patterns correlated inversely with the global cognition score (r = - 0.57; p = 0.04). In multiple variable analysis, the log-transformed burden of severe IIC patterns was independently associated with the global cognition score after controlling for demographics, premorbid estimated intelligence, injury severity, sedatives, and antiepileptic drugs (odds ratio 0.73, 95% confidence interval 0.60-0.88; p = 0.002). CONCLUSIONS: The burden of seizures and abnormal periodic or rhythmic patterns was independently associated with worse cognition at 3 months following TBI. Their impact on longer-term cognitive endpoints and the potential benefits of seizure detection and treatment in this population warrant prospective study.
Assuntos
Lesões Encefálicas Traumáticas , Eletroencefalografia , Adulto , Lesões Encefálicas Traumáticas/complicações , Cognição , Eletroencefalografia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Convulsões/diagnóstico , Adulto JovemRESUMO
OBJECTIVES: After traumatic brain injury, continuous electroencephalography is widely used to detect electrographic seizures. With the development of standardized continuous electroencephalography terminology, we aimed to describe the prevalence and burden of ictal-interictal patterns, including electrographic seizures after moderate-to-severe traumatic brain injury and to correlate continuous electroencephalography features with functional outcome. DESIGN: Post hoc analysis of the prospective, randomized controlled phase 2 multicenter INTREPID study (ClinicalTrials.gov: NCT00805818). Continuous electroencephalography was initiated upon admission to the ICU. The primary outcome was the 3-month Glasgow Outcome Scale-Extended. Consensus electroencephalography reviews were performed by raters certified in standardized continuous electroencephalography terminology blinded to clinical data. Rhythmic, periodic, or ictal patterns were referred to as "ictal-interictal continuum"; severe ictal-interictal continuum was defined as greater than or equal to 1.5 Hz lateralized rhythmic delta activity or generalized periodic discharges and any lateralized periodic discharges or electrographic seizures. SETTING: Twenty U.S. level I trauma centers. PATIENTS: Patients with nonpenetrating traumatic brain injury and postresuscitation Glasgow Coma Scale score of 4-12 were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among 152 patients with continuous electroencephalography (age 34 ± 14 yr; 88% male), 22 (14%) had severe ictal-interictal continuum including electrographic seizures in four (2.6%). Severe ictal-interictal continuum burden correlated with initial prognostic scores, including the International Mission for Prognosis and Analysis of Clinical Trials in Traumatic Brain Injury (r = 0.51; p = 0.01) and Injury Severity Score (r = 0.49; p = 0.01), but not with functional outcome. After controlling clinical covariates, unfavorable outcome was independently associated with absence of posterior dominant rhythm (common odds ratio, 3.38; 95% CI, 1.30-9.09), absence of N2 sleep transients (3.69; 1.69-8.20), predominant delta activity (2.82; 1.32-6.10), and discontinuous background (5.33; 2.28-12.96) within the first 72 hours of monitoring. CONCLUSIONS: Severe ictal-interictal continuum patterns, including electrographic seizures, were associated with clinical markers of injury severity but not functional outcome in this prospective cohort of patients with moderate-to-severe traumatic brain injury. Importantly, continuous electroencephalography background features were independently associated with functional outcome and improved the area under the curve of existing, validated predictive models.
Assuntos
Lesões Encefálicas Traumáticas/fisiopatologia , Lesões Encefálicas Traumáticas/reabilitação , Estado Terminal/terapia , Eletroencefalografia/métodos , Índice de Gravidade de Doença , Adulto , Estudos de Coortes , Feminino , Escala de Resultado de Glasgow , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Resultado do TratamentoRESUMO
As a follow-up to the 2008 state-of-the-art (SOTA) conference on traumatic brain injuries (TBIs), the 2015 event organized by the United States Department of Veterans Affairs (VA) Office of Research and Development (ORD) analysed the knowledge gained over the last 7 years as it relates to basic scientific methods, experimental findings, diagnosis, therapy, and rehabilitation of TBIs and blast-induced neurotraumas (BINTs). The current article summarizes the discussions and recommendations of the scientific panel attending the Preclinical Modeling and Therapeutic Development Workshop of the conference, with special emphasis on factors slowing research progress and recommendations for ways of addressing the most significant pitfalls.
Assuntos
Traumatismos por Explosões/epidemiologia , Lesões Encefálicas Traumáticas/epidemiologia , Modelos Animais de Doenças , Militares , United States Department of Veterans Affairs/tendências , Animais , Traumatismos por Explosões/psicologia , Traumatismos por Explosões/terapia , Lesões Encefálicas Traumáticas/psicologia , Lesões Encefálicas Traumáticas/terapia , Previsões , Humanos , Militares/psicologia , Estados Unidos/epidemiologiaRESUMO
In an established rat model of penetrating ballistic-like brain injury (PBBI), arylsulfatase B (ARSB; N-acetylgalactosamine 4-sulfatase) activity was significantly reduced at the ipsilateral site of injury, but unaffected at the contralateral site or in sham controls. In addition, the ARSB substrate chondroitin 4-sulfate (C4S) and total sulfated glycosaminoglycans increased. The mRNA expression of chondroitin 4-sulfotransferase 1 (C4ST1; CHST11) and the sulfotransferase activity rose at the ipsilateral site of injury (PBBI-I), indicating contributions from both increased production and reduced degradation to the accumulation of C4S. In cultured, fetal rat astrocytes, following scratch injury, the ARSB activity declined and the nuclear hypoxia inducible factor-1α increased significantly. In contrast, sulfotransferase activity and chondroitin 4-sulfotransferase expression increased following astrocyte exposure to TGF-ß1, but not following scratch. These different pathways by which C4S increased in the cell preparations were both evident in the response to injury in the PBBI-I model. Hence, findings support effects of injury because of mechanical disruption inhibiting ARSB and to chemical mediation by TGF-ß1 increasing CHST11 expression and sulfotransferase activity. The increase in C4S following traumatic brain injury is because of contributions from impaired degradation and enhanced synthesis of C4S which combine in the pathogenesis of the glial scar. This is the first report of how two mechanisms contribute to the increase in chondroitin 4-sulfate (C4S) in TBI. Following penetrating ballistic-like brain injury in a rat model and in the scratch model of injury in fetal rat astrocytes, Arylsulfatase B activity declined, leading to accumulation of C4S. TGF-ß1 exposure increased expression of chondroitin 4-sulfotransferase. Hence, the increase in C4S in TBI is attributable to both impaired degradation and enhanced synthesis, combining in the pathogenesis of the glial scar.
Assuntos
Lesões Encefálicas/metabolismo , Sulfatos de Condroitina/biossíntese , N-Acetilgalactosamina-4-Sulfatase/metabolismo , Sulfotransferases/biossíntese , Animais , Lesões Encefálicas/patologia , Células Cultivadas , Feminino , Masculino , Gravidez , Ratos , Ratos Sprague-DawleyRESUMO
Traumatic brain injury (TBI) is the leading cause of death and disability in the young, active population and expected to be the third leading cause of death in the whole world until 2020. The disease is frequently referred to as the silent epidemic, and many authors highlight the "unmet medical need" associated with TBI.The term traumatically evoked brain injury covers a heterogeneous group ranging from mild/minor/minimal to severe/non-salvageable damages. Severe TBI has long been recognized to be a major socioeconomical health-care issue as saving young lives and sometimes entirely restituting health with a timely intervention can indeed be extremely cost efficient.Recently it has been recognized that mild or minor TBI should be considered similarly important because of the magnitude of the patient population affected. Other reasons behind this recognition are the association of mild head injury with transient cognitive disturbances as well as long-term sequelae primarily linked to repeat (sport-related) injuries.The incidence of TBI in developed countries can be as high as 2-300/100,000 inhabitants; however, if we consider the injury pyramid, it turns out that severe and moderate TBI represents only 25-30 % of all cases, while the overwhelming majority of TBI cases consists of mild head injury. On top of that, or at the base of the pyramid, are the cases that never show up at the ER - the unreported injuries.Special attention is turned to mild TBI as in recent military conflicts it is recognized as "signature injury."This chapter aims to summarize the most important features of mild and repetitive traumatic brain injury providing definitions, stratifications, and triage options while also focusing on contemporary knowledge gathered by imaging and biomarker research.Mild traumatic brain injury is an enigmatic lesion; the classification, significance, and its consequences are all far less defined and explored than in more severe forms of brain injury.Understanding the pathobiology and pathomechanisms may aid a more targeted approach in triage as well as selection of cases with possible late complications while also identifying the target patient population where preventive measures and therapeutic tools should be applied in an attempt to avoid secondary brain injury and late complications.
Assuntos
Lesões Encefálicas/diagnóstico , Encéfalo/cirurgia , Traumatismos Craniocerebrais/diagnóstico , Diagnóstico por Imagem , Encéfalo/patologia , Lesões Encefálicas/prevenção & controle , Lesões Encefálicas/terapia , Traumatismos Craniocerebrais/prevenção & controle , Traumatismos Craniocerebrais/terapia , Humanos , Imageamento por Ressonância Magnética , Fatores de RiscoRESUMO
OBJECTIVES: Brain edema is a primary factor in the morbidity and mortality of traumatic brain injury (TBI). The various isoforms of aquaporin 4 (AQP4) and aquaporin 9 (AQP9) are important factors influencing edema following TBI. Others have reported that these AQPs are regulated by the transcription factor hypoxia inducible factor (HIF) 1α. Therefore, we examined the temporal alterations in the multiple isoforms of AQP4 and AQP9, and its possible upstream regulation by HIF1α, and evaluated whether different severities of penetrating injury influence these mechanisms. METHODS: In the penetrating ballistic-like brain injury (PBBI) model, a temporary cavity and resultant injury was formed by the rapid inflation/deflation (i.e. <40ms) of an elastic balloon attached to the end of the custom probe, injuring 10% of total rat brain volume. Tissue from the ipsilateral core and perilesional injury zones was collected. Total RNA was isolated at 4, 12, and 24h, 3 and 7days post-injury (sham and PBBI, n=6 per group). cDNA was synthesized using oligodT primers. Quantitative real time PCR was performed using Taqman expression assays for aqp4 (recognizing all isoforms), aqp9, and hif1α. Using separate animals, tissue lysate was collected at 4 and 24h, 3 and 7days post-injury and analyzed by immunoblot for protein expression of multiple isoforms of AQP4, the single known isoform of AQP9 and for expression of transcription factor HIF1α (sham, probe only control, and PBBI, n=8-10 per group). RESULTS: Global aqp4 mRNA was decreased at 24h (p<0.01) with PBBI. Three of the four known protein isoforms of AQP4 were detected, M1 (34kDa), M23 (32kDa) and isoform 3 (30kDa). AQP4 M1 decreased at 3 and 7days post-injury (p<0.001; p<0.01). AQP4 M23 levels were highly variable with no significant changes. AQP4 isoform 3 levels were decreased 3days post-PBBI (p<0.05). From 4, 12, and 24h aqp9 mRNA levels were decreased with injury (p<0.01, p<0.05, p<0.01) while AQP9 levels were decreased at 3 and 7days after PBBI (p<0.001, p<0.01). At 12 and 24h post-PBBI hif1α mRNA levels increased (p<0.05, p<0.01) but at 3 and 7days mRNA levels decreased (p<0.05, p<0.01). From 24h and 3 and 7days HIF1α protein levels were decreased (p<0.0001, p<0.0001, p<0.0001). In comparison to probe control, PBBI led to greater decreases in protein for AQP4 M1 (trend), AQP4 isoform 3 (trend), AQP9 (p<0.05) and HIF1α (p<0.05). CONCLUSION: PBBI is characterized by a loss of AQP4 M1, AQP4 isoform 3 and AQP9 at delayed time-points. The severity of the injury (PBBI versus probe control) increased these effects. Therefore, AQP9 and the AQP4 M1 isoform may be regulated by HIF1α, but not AQP4 isoform 3. This delayed loss of aquaporins may markedly reduce the ability of the brain to efflux water, contributing to the protracted edema that is a characteristic following severe penetrating TBI. Factors contributing to edema differ with different types and severities of TBI. For example, cellular based edema is more prominent in diffuse non-penetrating TBI whereas vasogenic edema is more prevalent with TBI involving hemorrhage. Molecular regulation leading to edema will likely also differ, such that treatments which have been suggested for non-hemorrhagic moderate TBI, such as the suppression of aquaporins, may be detrimental in more severe forms of TBI.
Assuntos
Aquaporina 4/metabolismo , Aquaporinas/metabolismo , Lesões Encefálicas/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Ferimentos por Arma de Fogo/metabolismo , Animais , Aquaporina 4/genética , Aquaporinas/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Masculino , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
During the past decade there has been an increasing recognition of the incidence of mild traumatic brain injury (mTBI) and a better understanding of the subtle neurological and cognitive deficits that may result from it. A substantial, albeit suboptimal, effort has been made to define diagnostic criteria for mTBI and improve diagnostic accuracy. Thus, biomarkers that can accurately and objectively detect brain injury after mTBI and, ideally, aid in clinical management are needed. In this review, we discuss the current research on serum biomarkers for mTBI including their rationale and diagnostic performances. Sensitive and specific biomarkers reflecting brain injury can provide important information regarding TBI pathophysiology and serve as candidate markers for predicting abnormal computed tomography findings and/or the development of residual deficits in patients who sustain an mTBI. We also outline the roles of biomarkers in settings of specific interest including pediatric TBI, sports concussions and military injuries, and provide perspectives on the validation of such markers for use in the clinic. Finally, emerging proteomics-based strategies for identifying novel markers will be discussed.
Assuntos
Biomarcadores/metabolismo , Lesões Encefálicas/diagnóstico , Lesões Encefálicas/metabolismo , Traumatismos em Atletas/sangue , Traumatismos em Atletas/diagnóstico , Biomarcadores/sangue , Concussão Encefálica/sangue , Concussão Encefálica/diagnóstico , Lesões Encefálicas/sangue , Tomada de Decisões , HumanosRESUMO
Proteomics and systems biology have significantly contributed to biomarker discovery in the field of brain injury. This study utilized 2D-DIGE-PMF-MS as a preliminary screen to detect biomarkers in a rat model of penetrating ballistic-like brain injury (PBBI). Brain-specific systems biology analysis of brain tissue identified 386 proteins having a fold change of more than 2, of which 321 proteins were increased and 65 were decreased 24 h after PBBI compared to sham controls. The majority of upregulated proteins were cytoskeletal (10.5%), nucleic acid binding (9.3%), or kinases (8.9%). Most proteins were involved in protein metabolism (22.7%), signal transduction (20.4%), and development (9.6%). Pathway analysis indicated that these proteins were involved in neurite outgrowth and cell differentiation. Semiquantitative Western blotting of 6, 24, 48, and 72 h after PBBI indicated ubiquitin carboxyl-terminal hydrolase isozyme L1 (a proposed traumatic brain injury biomarker in human clinical trials), tyrosine hydroxylase, and syntaxin-6 were found to be consistently elevated in brain tissue and cerebral spinal fluid after PBBI compared to sham controls. Combining proteomics and brain-specific systems biology can define underlying mechanisms of traumatic brain injury and provide valuable information in biomarker discovery that, in turn, may lead to novel therapeutic targets.
Assuntos
Traumatismos Cranianos Penetrantes/metabolismo , Proteoma/análise , Proteômica/métodos , Animais , Biomarcadores/análise , Biomarcadores/química , Química Encefálica , Bases de Dados de Proteínas , Modelos Animais de Doenças , Traumatismos Cranianos Penetrantes/patologia , Histocitoquímica , Masculino , Proteínas/análise , Proteoma/química , Ratos , Ratos Sprague-Dawley , Biologia de Sistemas/métodosRESUMO
STUDY OBJECTIVE: This study examines whether serum levels of glial fibrillary acidic protein breakdown products (GFAP-BDP) are elevated in patients with mild and moderate traumatic brain injury compared with controls and whether they are associated with traumatic intracranial lesions on computed tomography (CT) scan (positive CT result) and with having a neurosurgical intervention. METHODS: This prospective cohort study enrolled adult patients presenting to 3 Level I trauma centers after blunt head trauma with loss of consciousness, amnesia, or disorientation and a Glasgow Coma Scale (GCS) score of 9 to 15. Control groups included normal uninjured controls and trauma controls presenting to the emergency department with orthopedic injuries or a motor vehicle crash without traumatic brain injury. Blood samples were obtained in all patients within 4 hours of injury and measured by enzyme-linked immunosorbent assay for GFAP-BDP (nanograms/milliliter). RESULTS: Of the 307 patients enrolled, 108 were patients with traumatic brain injury (97 with GCS score 13 to 15 and 11 with GCS score 9 to 12) and 199 were controls (176 normal controls and 16 motor vehicle crash controls and 7 orthopedic controls). Receiver operating characteristic curves demonstrated that early GFAP-BDP levels were able to distinguish patients with traumatic brain injury from uninjured controls with an area under the curve of 0.90 (95% confidence interval [CI] 0.86 to 0.94) and differentiated traumatic brain injury with a GCS score of 15 with an area under the curve of 0.88 (95% CI 0.82 to 0.93). Thirty-two patients with traumatic brain injury (30%) had lesions on CT. The area under these curves for discriminating patients with CT lesions versus those without CT lesions was 0.79 (95% CI 0.69 to 0.89). Moreover, the receiver operating characteristic curve for distinguishing neurosurgical intervention from no neurosurgical intervention yielded an area under the curve of 0.87 (95% CI 0.77 to 0.96). CONCLUSION: GFAP-BDP is detectable in serum within an hour of injury and is associated with measures of injury severity, including the GCS score, CT lesions, and neurosurgical intervention. Further study is required to validate these findings before clinical application.
Assuntos
Lesões Encefálicas/sangue , Encéfalo/patologia , Proteína Glial Fibrilar Ácida/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Lesões Encefálicas/patologia , Lesões Encefálicas/terapia , Estudos de Casos e Controles , Feminino , Escala de Coma de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Centros de Traumatologia , Adulto JovemRESUMO
INTRODUCTION: Authors of several studies have studied biomarkers and computed tomography (CT) findings in the acute phase after severe traumatic brain injury (TBI). However, the correlation between structural damage as assessed by neuroimaging and biomarkers has not been elucidated. The aim of this study was to investigate the relationships among neuronal (Ubiquitin carboxy-terminal hydrolase L1 [UCH-L1]) and glial (glial fibrillary acidic protein [GFAP]) biomarker levels in serum, neuroradiological findings and outcomes after severe TBI. METHODS: The study recruited patients from four neurotrauma centers. Serum samples for UCH-L1 and GFAP were obtained at the time of hospital admission and every 6 hours thereafter. CT scans of the brain were obtained within 24hrs of injury. Outcome was assessed by Glasgow Outcome Scale (GOS) at discharge and at 6 months. RESULTS: 81 severe TBI patients and 167 controls were enrolled. The mean serum levels of UCH-L1 and GFAP were higher (p < 0.001) in TBI patients compared to controls. UCH-L1 and GFAP serum levels correlated significantly with Glasgow Coma Scale (GCS) and CT findings. GFAP levels were higher in patients with mass lesions than in those with diffuse injury (2.95 ± 0.48 ng/ml versus 0.74 ± 0.11 ng/ml) while UCH-L1 levels were higher in patients with diffuse injury (1.55 ± 0.18 ng/ml versus 1.21 ± 0.15 ng/ml, p = 0.0031 and 0.0103, respectively). A multivariate logistic regression showed that UCH-L1 was the only independent predictor of death at discharge [adjusted odds ratios 2.95; 95% confidence interval, 1.46-5.97], but both UCH-L1 and GFAP levels strongly predicted death 6 months post-injury. CONCLUSIONS: Relationships between structural changes detected by neuroimaging and biomarkers indicate each biomarker may reflect a different injury pathway. These results suggest that protein biomarkers could provide better characterization of subjects at risk for specific types of cellular damage than that obtained with neuroimaging alone, as well as provide valuable information about injury severity and outcome after severe TBI.
Assuntos
Lesões Encefálicas/sangue , Lesões Encefálicas/diagnóstico por imagem , Proteína Glial Fibrilar Ácida/sangue , Tomografia Computadorizada por Raios X , Ubiquitina Tiolesterase/sangue , Adulto , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neuroglia/metabolismo , Neuroglia/patologia , Neurônios/metabolismo , Neurônios/patologia , Estudos Prospectivos , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X/métodos , Adulto JovemRESUMO
Interest in developing NMDA receptor antagonists with reduced side-effects for neurological and psychiatric disorders has been re-energized by the recent introduction of esketamine into clinical practice for treatment-resistant depression. Structural analogs of dextromethorphan bind with low affinity to the NMDA receptor ion channel, have functional effects in vivo, and generally display a lower propensity for side-effects than that of ketamine and other higher affinity antagonists. As such, the aim of the present study was to determine whether a series of N-substituted-3-alkoxy-substituted dextromethorphan analogs produce their anticonvulsant effects through NMDA receptor blockade. Compounds were studied against NMDA-induced seizures in rats. Compounds were administered intracerebroventricularly in order to mitigate confounds of drug metabolism that arise from systemic administration. Comparison of the anticonvulsant potencies to their affinities for NMDA, σ1, and σ2 binding sites were made in order to evaluate the contribution of these receptors to anticonvulsant efficacy. The potencies to block convulsions were positively associated with their affinities to bind to the NMDA receptor ion channel ([3H]-TCP binding) (r = 0.71, p < 0.05) but not to σ1 receptors ([3H]-SKF 10047 binding) (r = -0.31, p = 0.46) or to σ2 receptors ([3H]-DTG binding) (p = -0.38, p = 0.36). This is the first report demonstrating that these dextromethorphan analogs are functional NMDA receptor antagonists in vivo. Given their potential therapeutic utility and favorable side-effect profiles, such low affinity NMDA receptor antagonists could be considered for further development in neurological (e.g., anticonvulsant) and psychiatric (e.g., antidepressant) disorders.
Assuntos
Anticonvulsivantes/administração & dosagem , Dextrometorfano/análogos & derivados , Dextrometorfano/administração & dosagem , Dextrorfano/administração & dosagem , Agonistas de Aminoácidos Excitatórios/efeitos adversos , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , N-Metilaspartato/efeitos adversos , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico , Álcoois/química , Animais , Anticonvulsivantes/metabolismo , Sítios de Ligação , Dextrometorfano/metabolismo , Dextrorfano/metabolismo , Modelos Animais de Doenças , Antagonistas de Aminoácidos Excitatórios/metabolismo , Infusões Intraventriculares , Ligantes , Masculino , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores sigma/metabolismo , Resultado do Tratamento , Receptor Sigma-1RESUMO
Ubiquitin C-terminal hydrolase-L1 (UCH-L1), also called neuronal-specific protein gene product 9.5, is a highly abundant protein in the neuronal cell body and has been identified as a possible biomarker on the basis of a recent proteomic study. In this study, we examined whether UCH-L1 was significantly elevated in cerebrospinal fluid (CSF) following controlled cortical impact (CCI) and middle cerebral artery occlusion (MCAO; model of ischemic stroke) in rats. Quantitative immunoblots of rat CSF revealed a dramatic elevation of UCH-L1 protein 48 h after severe CCI and as early as 6 h after mild (30 min) and severe (2 h) MCAO. A sandwich enzyme-linked immunosorbent assay constructed to measure UCH-L1 sensitively and quantitatively showed that CSF UCH-L1 levels were significantly elevated as early as 2 h and up to 48 h after CCI. Similarly, UCH-L1 levels were also significantly elevated in CSF from 6 to 72 h after 30 min of MCAO and from 6 to 120 h after 2 h of MCAO. These data are comparable to the profile of the calpain-produced alphaII-spectrin breakdown product of 145 kDa biomarker. Importantly, serum UCH-L1 biomarker levels were also significantly elevated after CCI. Similarly, serum UCH-L1 levels in the 2-h MCAO group were significantly higher than those in the 30-min group. Taken together, these data from two rat models of acute brain injury strongly suggest that UCH-L1 is a candidate brain injury biomarker detectable in biofluid compartments (CSF and serum).
Assuntos
Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Lesões Encefálicas/sangue , Lesões Encefálicas/líquido cefalorraquidiano , Infarto da Artéria Cerebral Média/sangue , Infarto da Artéria Cerebral Média/líquido cefalorraquidiano , Ubiquitina Tiolesterase/sangue , Ubiquitina Tiolesterase/líquido cefalorraquidiano , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley , Espectrina/líquido cefalorraquidianoRESUMO
BACKGROUND: Inflammatory cytokines play a crucial role in the pathophysiology of traumatic brain injury (TBI), exerting either deleterious effects on the progression of tissue damage or beneficial roles during recovery and repair. NNZ-2566, a synthetic analogue of the neuroprotective tripeptide Glypromate, has been shown to be neuroprotective in animal models of brain injury. The goal of this study was to determine the effects of NNZ-2566 on inflammatory cytokine expression and neuroinflammation induced by penetrating ballistic-like brain injury (PBBI) in rats. METHODS: NNZ-2566 or vehicle (saline) was administered intravenously as a bolus injection (10 mg/kg) at 30 min post-injury, immediately followed by a continuous infusion of NNZ-2566 (3 mg/kg/h), or equal volume of vehicle, for various durations. Inflammatory cytokine gene expression from the brain tissue of rats exposed to PBBI was evaluated using microarray, quantitative real time PCR (QRT-PCR), and enzyme-linked immunosorbent assay (ELISA) array. Histopathology of the injured brains was examined using hematoxylin and eosin (H&E) and immunocytochemistry of inflammatory cytokine IL-1beta. RESULTS: NNZ-2566 treatment significantly reduced injury-mediated up-regulation of IL-1beta, TNF-alpha, E-selectin and IL-6 mRNA during the acute injury phase. ELISA cytokine array showed that NZ-2566 treatment significantly reduced levels of the pro-inflammatory cytokines IL-1beta, TNF-alpha and IFN-gamma in the injured brain, but did not affect anti-inflammatory cytokine IL-6 levels. CONCLUSION: Collectively, these results suggest that the neuroprotective effects of NNZ-2566 may, in part, be functionally attributed to the compound's ability to modulate expression of multiple neuroinflammatory mediators in the injured brain.
Assuntos
Lesões Encefálicas/tratamento farmacológico , Citocinas/efeitos dos fármacos , Encefalite/tratamento farmacológico , Traumatismos Cranianos Penetrantes/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Oligopeptídeos/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Lesões Encefálicas/complicações , Lesões Encefálicas/fisiopatologia , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Encefalite/etiologia , Encefalite/fisiopatologia , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Traumatismos Cranianos Penetrantes/complicações , Traumatismos Cranianos Penetrantes/fisiopatologia , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/metabolismo , Masculino , Fármacos Neuroprotetores/uso terapêutico , Oligopeptídeos/uso terapêutico , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Resultado do TratamentoRESUMO
Protein changes induced by traumatic or ischemic brain injury can serve as diagnostic markers as well as therapeutic targets for neuroprotection. The focus of this chapter is to provide a representative overview of preclinical brain injury and proteomics analysis protocols for evaluation and discovery of novel biomarkers. Detailed surgical procedures have been provided for inducing MCAo and implantation of chronic indwelling cannulas for drug delivery. Sample collection and tissue processing techniques for collection of blood, CSF, and brain are also described including standard biochemical methodology for the proteomic analysis of these tissues.The dynamics of proteomic analysis is a multistep process comprising sample preparation, separation, quantification, and identification of proteins. Our approach is to separate proteins first by two-dimensional gel electrophoresis according to charge and molecular mass. Proteins are then fragmented and analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Identification of proteins can be achieved by comparing the mass-to-charge data to protein sequences in respective databases.
Assuntos
Isquemia Encefálica/fisiopatologia , Proteínas do Tecido Nervoso/análise , Proteômica/métodos , Animais , Encéfalo/patologia , Encéfalo/fisiologia , Humanos , Infarto da Artéria Cerebral Média , Proteoma/análise , RatosRESUMO
Glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase (UCH-L1), markers of glial and neuronal cell body injury, respectively, have been previously selected by the Operation Brain Trauma Therapy (OBTT) pre-clinical therapy and biomarker screening consortium as drug development tools. However, traumatic axonal injury (TAI) also represents a major consequence and determinant of adverse outcomes after traumatic brain injury (TBI). Thus, biomarkers capable of assessing TAI are much needed. Neurofilaments (NFs) are found exclusively in axons. Here, we evaluated phospho-neurofilament-H (pNF-H) protein as a possible new TAI marker in serum and cerebrospinal fluid (CSF) across three rat TBI models in studies carried out by the OBTT consortium, namely, controlled cortical impact (CCI), parasagittal fluid percussion (FPI), and penetrating ballistics-like brain injury (PBBI). We indeed found that CSF and serum pNF-H levels are robustly elevated by 24 h post-injury in all three models. Further, in previous studies by OBTT, levetiracetam showed the most promising benefits, whereas nicotinamide showed limited benefit only at high dose (500 mg/kg). Thus, serum samples from the same repository collected by OBTT were evaluated. Treatment with 54 mg/kg intravenously of levetiracetam in the CCI model and 170 mg/kg in the PBBI model significantly attenuated pNF-H levels at 24 h post-injury as compared to respective vehicle groups. In contrast, nicotinamide (50 or 500 mg/kg) showed no reduction of pNF-H levels in CCI or PBBI models. Our current study suggests that pNF-H is a useful theranostic blood-based biomarker for TAI across different rodent TBI models. In addition, our data support levetiracetam as the most promising TBI drug candidate screened by OBTT to date.
Assuntos
Biomarcadores/sangue , Lesões Encefálicas Traumáticas/sangue , Proteínas de Neurofilamentos/sangue , Animais , Biomarcadores/líquido cefalorraquidiano , Lesões Encefálicas Traumáticas/líquido cefalorraquidiano , Modelos Animais de Doenças , Levetiracetam/farmacologia , Proteínas de Neurofilamentos/líquido cefalorraquidiano , Niacinamida/farmacologia , Nootrópicos/farmacologia , Ratos , Ratos Sprague-Dawley , Nanomedicina Teranóstica/métodos , Complexo Vitamínico B/farmacologiaRESUMO
Systemic cooling to achieve brain hypothermia has been investigated as a neuroprotective therapy but can present serious adverse effects. Here we describe a novel method to selectively cool the rat brain and investigate its neuroprotective effects following transient middle cerebral artery occlusion (MCAo). The novelty of our method of selective brain cooling (SBC) was that the extraluminal cooling of the carotid arterial blood was achieved by using a cooling cuff wrapped around each common carotid artery (CCA). Within 20 min of CCA cooling, brain temperature could be lowered by 2-5 degrees C below the baseline and maintained stable for approximately 2 h while maintaining body temperature at 37 degrees C. No adverse effects of SBC were observed on systemic physiology, regional cerebral blood flow (rCBF), bleeding time, or tissue histology in normal animals. In rats having sustained 2-h MCAo, intra-ischemic SBC for 90 min, initiated 30 min following the onset of ischemia, significantly reduced infarction measured at 24 h post-injury (normothermic rats=312+/-51 mm3, SBC rats=139+/-83 mm3). In subgroup experiments, the incidence of peri-infarct depolarization (PID) was assessed during the MCAo and cooling period. Compared to normothermic but ischemic rats, SBC significantly reduced the number of PID events from 6.2+/-2.5 to 2.0+/-2.5, and reduced infarct volumes from 323+/-79 to 139+/-102 mm3. In conclusion, this extralumimal cooling method of SBC provides a safe and efficient approach to rapidly and safely achieve hypothermic neuroprotection.
Assuntos
Encéfalo/irrigação sanguínea , Artérias Carótidas , Hipertermia Induzida/métodos , Infarto da Artéria Cerebral Média/terapia , Degeneração Neural/prevenção & controle , Animais , Encéfalo/patologia , Circulação Cerebrovascular/fisiologia , Infarto da Artéria Cerebral Média/patologia , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
Acute "silent" seizures after brain injury are associated with a worsening of patient outcome and are often refractory to anti-epileptic drug (AED) therapy. In the present study we evaluated topiramate (TPM, 1-30 mg/kg, i.v.) in a rodent model of spontaneous non-convulsive seizure (NCS) activity induced by focal cerebral ischemia. For seizure detection, electroencephalographic (EEG) activity was continuously recorded for 24h in male Sprague-Dawley rats subjected to permanent middle cerebral artery occlusion (MCAo). Infarct volume, neurological deficit, and NCS were evaluated by an experimenter blinded to the treatment group. All vehicle treated rats (7/7) exhibited NCS following MCAo. TPM treatment, delivered at 20 min post-occlusion and prior to onset of NCS activity, dose-dependently reduced the incidence of NCS (ED(50)=21.1mg/kg). The highest dose of TPM tested (30 mg/kg) exhibited maximal reductions of 76% in the number of NCS/rat (vehicle=22.1+/-5.3, TPM=4.4+/-3.2, P<0.05), 80% in the total time of NCS (vehicle=1259+/-337 s, TPM=253+/-220 s, P<0.05), 20% in core brain infarction (vehicle=45+/-1%, TPM=36+/-4%, percent of ipsilateral volume corrected for swelling, P<0.05), and 38% in neurological deficit score (vehicle=7.4+/-1.2, TPM=4.6+/-1.5, P<0.05). Despite efficacy as a pre-seizure treatment, TPM was not effective when delivered immediately following onset of the first NCS event (36+/-5 min post-MCAo). In conclusion, TPM exhibited significant efficacy for the prophylactic treatment of brain-injury induced NCS and represents a novel class of AED for treatment of this type of silent brain seizure.
Assuntos
Anticonvulsivantes/uso terapêutico , Isquemia Encefálica/complicações , Frutose/análogos & derivados , Convulsões/prevenção & controle , Animais , Eletroencefalografia , Frutose/uso terapêutico , Masculino , Ratos , Ratos Sprague-Dawley , Convulsões/etiologia , TopiramatoRESUMO
OBJECTIVE AND IMPORTANCE: Cortical spreading depolarizations (CSD) are waves of mass tissue depolarization that mediate progressive development of cortical infarction in animal models and occur in approximately 50% of patients with acute brain injury. Here we performed multi-modal cerebral monitoring to investigate pathologies associated with CSD occurrence in a case of severe traumatic brain injury. CLINICAL PRESENTATION: A 20 years old male suffering severe traumatic brain injury from a fall had extensive frontal subdural and intraparenchymal hemorrhage with mass effect. Craniectomy was performed for hematoma evacuation and decompression. INTERVENTION: During surgery, a subdural electrocorticography (ECoG) electrode strip, along with microdialysis and PtiO2 probes, was placed beside injured cortex for CSD monitoring. Within 13-81 hours post-injury, 34 CSD occurred. CSD incidence increased during spontaneous hyperthermia and decreased during induced normothermia. Periods of CSD activity were also associated with low brain glucose (<0.10 mmol/l), elevated glutamate (>40 mmol/l) and lactate/pyruvate (>40), and PtiO2<10 mmHg. CSD caused progressive deterioration of ECoG activity only in regions with infarction at follow-up on day 27. CONCLUSION: Repetitive mass tissue depolarizations accompanied a negative course of hemorrhagic lesion progression in the presence of ischemic conditions after traumatic brain injury. Whether as cause or effect, CSD may represent an inherent component of progressive metabolic failure leading to tissue death, and temperature appears to be an important factor influencing their occurrence. Continuous ECoG is a valuable tool for monitoring subclinical events such as CSD and seizures and for translational research in acute brain injury mechanisms and therapeutics.
Assuntos
Lesões Encefálicas/fisiopatologia , Córtex Cerebral/lesões , Depressão Alastrante da Atividade Elétrica Cortical , Hemorragia Intracraniana Traumática/fisiopatologia , Adulto , Lesões Encefálicas/complicações , Lesões Encefálicas/patologia , Progressão da Doença , Eletroencefalografia , Febre/etiologia , Febre/fisiopatologia , Humanos , Hemorragia Intracraniana Traumática/etiologia , Hemorragia Intracraniana Traumática/patologia , Masculino , Recuperação de Função Fisiológica , Fatores de TempoRESUMO
PRIMARY OBJECTIVE: Recent efforts have been aimed at developing a panel of protein biomarkers for the diagnosis/prognosis of the neurological damage associated with acute brain injury. METHODS AND PROCEDURES: This study utilized high-throughput immunoblotting (HTPI) technology to compare changes between two animal models of acute brain injury: penetrating ballistic-like brain injury (PBBI) which mimics the injury created by a gunshot wound and transient middle cerebral artery occlusion (MCAo) which is a model of stroke. Brain and blood were collected at 24-hours post-injury. MAIN OUTCOMES AND RESULTS: This study identified the changes in 18 proteins following PBBI and 17 proteins following MCAo out of a total of 998 screened proteins. Distinct differences were observed between the two models: five proteins were up- or down-regulated in both models, 23 proteins changed in only one model and one protein was differentially expressed. Western blots were used to verify HTPI results for selected proteins with measurable changes observed in both blood and brain for the proteins STAT3, Tau, PKA RII beta, 14-3-3 epsilon and p43/EMAPII. CONCLUSIONS: These results suggest distinct post-injury protein profiles between brain injury types (traumatic vs. ischemic) that will facilitate strategies aimed at the differential diagnosis and prognosis of acute brain injury.
Assuntos
Hemorragia Cerebral Traumática/metabolismo , Infarto da Artéria Cerebral Média/metabolismo , Proteínas de Membrana/análise , Ferimentos por Arma de Fogo/metabolismo , Animais , Biomarcadores/análise , Western Blotting , Química Encefálica , Hemorragia Cerebral Traumática/patologia , Immunoblotting/métodos , Infarto da Artéria Cerebral Média/patologia , Masculino , Modelos Animais , Ratos , Ratos Sprague-Dawley , Ferimentos por Arma de Fogo/patologiaRESUMO
Operation brain trauma therapy (OBTT) is a multi-center, pre-clinical drug and biomarker screening consortium for traumatic brain injury (TBI). Therapies are screened across three rat models (parasagittal fluid percussion injury, controlled cortical impact [CCI], and penetrating ballistic-like brain injury). Operation brain trauma therapy seeks to define therapies that show efficacy across models that should have the best chance in randomized clinical trials (RCTs) and/or to define model-dependent therapeutic effects, including TBI protein biomarker responses, to guide precision medicine-based clinical trials in targeted pathologies. The results of the first five therapies tested by OBTT (nicotinamide, erythropoietin, cyclosporine [CsA], simvastatin, and levetiracetam) were published in the Journal of Neurotrauma. Operation brain trauma therapy now describes preliminary results on four additional therapies (glibenclamide, kollidon-VA64, AER-271, and amantadine). To date, levetiracetam was beneficial on cognitive outcome, histology, and/or biomarkers in two models. The second most successful drug, glibenclamide, improved motor function and histology in CCI. Other therapies showed model-dependent effects (amantadine and CsA). Critically, glial fibrillary acidic protein levels predicted treatment effects. Operation brain trauma therapy suggests that levetiracetam merits additional pre-clinical and clinical evaluation and that glibenclamide and amantadine merit testing in specific TBI phenotypes. Operation brain trauma therapy has established that rigorous, multi-center consortia could revolutionize TBI therapy and biomarker development.