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Abstract
Blast injury has become the major life- and function-threatening injuries in recent warfares. There is increased research interest in the mental disorders caused by blast-induced traumatic brain injury (bTBI), which has been proved as one of the "signature wounds" in modern battlefield. We reviewed the recent progresses in bTBI-related researches and concluded that the new era of blast injury research has shifted from the traditional physical impairments to cognitive dysfunctional/mental disorders that are proved to be more related to the outcome of combat casualty care.
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Affiliation(s)
- Yan Zhao
- Molecular Biology Center, State Key Laboratory of Trauma, Burns and Combined Injury, Research Institute of Surgery and Daping Hospital, Third Military Medical University, Chongqing 400042, China
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52
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Salzar RS, Treichler D, Wardlaw A, Weiss G, Goeller J. Experimental Investigation of Cavitation as a Possible Damage Mechanism in Blast-Induced Traumatic Brain Injury in Post-Mortem Human Subject Heads. J Neurotrauma 2017; 34:1589-1602. [PMID: 27855566 DOI: 10.1089/neu.2016.4600] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The potential of blast-induced traumatic brain injury from the mechanism of localized cavitation of the cerebrospinal fluid (CSF) is investigated. While the mechanism and criteria for non-impact blast-induced traumatic brain injury is still unknown, this study demonstrates that local cavitation in the CSF layer of the cranial volume could contribute to these injuries. The cranial contents of three post-mortem human subject (PMHS) heads were replaced with both a normal saline solution and a ballistic gel mixture with a simulated CSF layer. Each were instrumented with multiple pressure transducers and placed inside identical shock tubes at two different research facilities. Sensor data indicates that cavitation may have occurred in the PMHS models at pressure levels below those for a 50% risk of blast lung injury. This study points to skull flexion, the result of the shock wave on the front of the skull leading to a negative pressure in the contrecoup, as a possible mechanism that contributes to the onset of cavitation. Based on observation of intracranial pressure transducer data from the PMHS model, cavitation onset is thought to occur from approximately a 140 kPa head-on incident blast.
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Affiliation(s)
- Robert S Salzar
- 1 Center for Applied Biomechanics, the University of Virginia , Charlottesville, Virginia
| | | | | | - Greg Weiss
- 3 Applied Research Associates, Inc. , Littleton, Colorado
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53
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Chen HJ, Xu C, Li Y, Chen ZQ, Li GH, Duan ZX, Li XX, Zhang JY, Wang Z, Feng H, Li BC. An open air research study of blast-induced traumatic brain injury to goats. Chin J Traumatol 2017; 18:267-74. [PMID: 26777709 DOI: 10.1016/j.cjtee.2015.11.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
PURPOSE We once reported blast-induced traumatic brain injury (bTBI) in confined space. Here, bTBI was studied again on goats in the open air using 3.0 kg trinitrotoluene. METHODS The goats were placed at 2, 4, 6 and 8 m far from explosion center. Trinitrotoluene (TNT) was used as the source of the blast wave and the pressure at each distance was recorded. The systemic physiology, electroencephalogram, serum level of S-100 beta, and neuron specific enolase (NSE) were determined pre and post the exposure. Neuroanatomy and neuropathology were observed 4 h after the exposure. RESULTS Simple blast waveforms were recorded with parameters of 702.8 kPa-0.442 ms, 148.4 kPa-2.503 ms, 73.9 kPa-3.233 ms, and 41.9 kPa-5.898 ms at 2, 4, 6 and 8 m respectively. Encephalic blast overpressure was on the first time recorded in the literature by us at 104.2 kPa-0.60 ms at 2 m, where mortality and burn rate were 44% and 44%. Gross examination showed that bTBI was mainly manifested as congestive expansion of blood vessels and subarachnoid hemorrhage, which had a total incidence of 25% and 19% in 36 goats. Microscopical observation found that the main pathohistological changes were enlarged perivascular space (21/36, 58%), small hemorrhages (9/36, 25%), vascular dilatation and congestion (8/36, 22%), and less subarachnoid hemorrhage (2/36, 6%). After explosion, serum levels of S-100b and NSE were elevated, and EEG changed into slow frequency with declined amplitude. The results indicated that severity and incidence of bTBI is related to the intensity of blast overpressure. CONCLUSION Blast wave can pass through the skull to directly injure brain tissue.
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Affiliation(s)
- Hui-Jun Chen
- Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, China
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Toklu HZ, Sakarya Y, Tümer N. A Proteomic Evaluation of Sympathetic Activity Biomarkers of the Hypothalamus-Pituitary-Adrenal Axis by Western Blotting Technique Following Experimental Traumatic Brain Injury. Methods Mol Biol 2017; 1598:313-325. [PMID: 28508370 DOI: 10.1007/978-1-4939-6952-4_16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Endocrine disorders and autonomic dysfunction are common paradigms following traumatic brain injury (TBI). Alterations in the hypothalamus-pituitary-adrenal (HPA) axis following TBI may result in impaired vasopressor response, energy imbalance, fatigue, depression, or neurological disorders. Autonomic dysfunction is a common disorder following TBI. The sympathetic activity markers on HPA axis can be measured by Western blot protein analysis. Tyrosine hydroxylase, dopamine beta hydroxylase are the key enzymes for the synthesis of norepinephrine; and neuropeptide Y (NPY) is the peptide that is co-stored and co-released with norepinephrine. Thus, the present chapter reviews the experimental protocols for Western blot protein analysis for the measurement of biomarkers that indicate sympathetic activity in brain regions (hypothalamus, pituitary, cerebral cortex, and cerebellum) following TBI.
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Affiliation(s)
- Hale Zerrin Toklu
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, ARB R5-234, 1200 Newell Drive, PO 100267, Gainesville, FL, 32610, USA.
- Geriatric Research Education and Clinical Center, Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL, USA.
- North Florida Regional Medical Center, Department of Graduate Medical Education, 6500 W Newberry Rd, Gainesville, 32605, FL, USA.
| | - Yasemin Sakarya
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, ARB R5-234, 1200 Newell Drive, PO 100267, Gainesville, FL, 32610, USA
| | - Nihal Tümer
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, ARB R5-234, 1200 Newell Drive, PO 100267, Gainesville, FL, 32610, USA
- Geriatric Research Education and Clinical Center, Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL, USA
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55
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Yeh P, Guan Koay C, Wang B, Morissette J, Sham E, Senseney J, Joy D, Kubli A, Yeh C, Eskay V, Liu W, French LM, Oakes TR, Riedy G, Ollinger J. Compromised Neurocircuitry in Chronic Blast-Related Mild Traumatic Brain Injury. Hum Brain Mapp 2017; 38:352-369. [PMID: 27629984 PMCID: PMC6867097 DOI: 10.1002/hbm.23365] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 08/16/2016] [Accepted: 08/23/2016] [Indexed: 12/20/2022] Open
Abstract
The aim of this study was to apply recently developed automated fiber segmentation and quantification methods using diffusion tensor imaging (DTI) and DTI-based deterministic and probabilistic tractography to access local and global diffusion changes in blast-induced mild traumatic brain injury (bmTBI). Two hundred and two (202) male active US service members who reported persistent post-concussion symptoms for more than 6 months after injury were recruited. An additional forty (40) male military controls were included for comparison. DTI results were examined in relation to post-concussion and post-traumatic stress disorder (PTSD) symptoms. No significant group difference in DTI metrics was found using voxel-wise analysis. However, group comparison using tract profile analysis and tract specific analysis, as well as single subject analysis using tract profile analysis revealed the most prominent white matter microstructural injury in chronic bmTBI patients over the frontal fiber tracts, that is, the front-limbic projection fibers (cingulum bundle, uncinate fasciculus), the fronto-parieto-temporal association fibers (superior longitudinal fasciculus), and the fronto-striatal pathways (anterior thalamic radiation). Effects were noted to be sensitive to the number of previous blast exposures, with a negative association between fractional anisotropy (FA) and time since most severe blast exposure in a subset of the multiple blast-exposed group. However, these patterns were not observed in the subgroups classified using macrostructural changes (T2 white matter hyperintensities). Moreover, post-concussion symptoms and PTSD symptoms, as well as neuropsychological function were associated with low FA in the major nodes of compromised neurocircuitry. Hum Brain Mapp 38:352-369, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Ping‐Hong Yeh
- Henry Jackson Foundation for the Advancement of Military MedicineRockledgeMaryland
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Cheng Guan Koay
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Binquan Wang
- Henry Jackson Foundation for the Advancement of Military MedicineRockledgeMaryland
| | - John Morissette
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Elyssa Sham
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Justin Senseney
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - David Joy
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Alex Kubli
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Chen‐Haur Yeh
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Victora Eskay
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Wei Liu
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Louis M. French
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
- Center for Neuroscience and Regenerative Medicine (CNRM)Uniformed Services University of the Health Sciences (USUHS)BethesdaMaryland
| | - Terrence R. Oakes
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Gerard Riedy
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
- Center for Neuroscience and Regenerative Medicine (CNRM)Uniformed Services University of the Health Sciences (USUHS)BethesdaMaryland
| | - John Ollinger
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
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56
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Kawoos U, Gu M, Lankasky J, McCarron RM, Chavko M. Effects of Exposure to Blast Overpressure on Intracranial Pressure and Blood-Brain Barrier Permeability in a Rat Model. PLoS One 2016; 11:e0167510. [PMID: 27907158 PMCID: PMC5132256 DOI: 10.1371/journal.pone.0167510] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 11/15/2016] [Indexed: 12/13/2022] Open
Abstract
Exposure to blast overpressure (BOP) activates a cascade of pathological processes including changes in intracranial pressure (ICP) and blood-brain barrier (BBB) permeability resulting in traumatic brain injury (TBI). In this study the effect of single and multiple exposures at two intensities of BOP on changes in ICP and BBB permeability in Sprague-Dawley rats was evaluated. Animals were exposed to a single or three repetitive (separated by 0.5 h) BOPs at 72 kPa or 110 kPa. ICP was monitored continuously via telemetry for 6 days after exposure to BOP. The alteration in the permeability of BBB was determined by extravasation of Evans Blue (EB) into brain parenchyma. A significant increase in ICP was observed in all groups except the single 72 kPa BOP group. At the same time a marked increase in BBB permeability was also seen in various parts of the brain. The extent of ICP increase as well as BBB permeability change was dependent on intensity and frequency of blast.
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Affiliation(s)
- Usmah Kawoos
- Department of Neurotrauma, Naval Medical Research Center, Silver Spring, MD, United States of America
| | - Ming Gu
- Department of Neurotrauma, Naval Medical Research Center, Silver Spring, MD, United States of America
| | - Jason Lankasky
- Department of Neurotrauma, Naval Medical Research Center, Silver Spring, MD, United States of America
| | - Richard M McCarron
- Department of Neurotrauma, Naval Medical Research Center, Silver Spring, MD, United States of America
- Department of Surgery, Uniformed Services University of the Health Sciences and the Walter Reed National Military Medical Center, Bethesda, MD, United States of America
| | - Mikulas Chavko
- Department of Neurotrauma, Naval Medical Research Center, Silver Spring, MD, United States of America
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57
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Abstract
Extremity injury is a significant burden to those injured in explosive incidents and local ischaemia can result in poor functionality in salvaged limbs. This study examined whether blast injury to a limb resulted in a change in endothelial phenotype leading to changes to the surrounding tissue. The hind limbs of terminally anaesthetized rabbits were subjected to one of four blast exposures (high, medium, low, or no blast). Blood samples were analyzed for circulating endothelial cells pre-injury and at 1, 6, and 11 h postinjury as well as analysis for endothelial activation pre-injury and at 1, 6, and 12 h postinjury. Post-mortem tissue (12 h post-injury) was analysed for both protein and mRNA expression and also for histopathology. The high blast group had significantly elevated levels of circulating endothelial cells 6 h postinjury. This group also had significantly elevated tissue mRNA expression of IL-6, E-selectin, TNF-α, HIF-1, thrombomodulin, and PDGF. There was a significant correlation between blast dose and the degree of tissue pathology (hemorrhage, neutrophil infiltrate, and oedema) with the worst scores in the high blast group. This study has demonstrated that blast injury can activate the endothelium and in some cases cause damage that in turn leads to pathological changes in the surrounding tissue. For the casualty injured by an explosion the damaging effects of hemorrhage and shock could be exacerbated by blast injury and vice versa so that even low levels of blast become damaging, all of which could affect tissue functionality and long-term outcomes.
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58
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Rodriguez O, Schaefer ML, Wester B, Lee YC, Boggs N, Conner HA, Merkle AC, Fricke ST, Albanese C, Koliatsos VE. Manganese-Enhanced Magnetic Resonance Imaging as a Diagnostic and Dispositional Tool after Mild-Moderate Blast Traumatic Brain Injury. J Neurotrauma 2016; 33:662-71. [PMID: 26414591 PMCID: PMC4827293 DOI: 10.1089/neu.2015.4002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Traumatic brain injury (TBI) caused by explosive munitions, known as blast TBI, is the signature injury in recent military conflicts in Iraq and Afghanistan. Diagnostic evaluation of TBI, including blast TBI, is based on clinical history, symptoms, and neuropsychological testing, all of which can result in misdiagnosis or underdiagnosis of this condition, particularly in the case of TBI of mild-to-moderate severity. Prognosis is currently determined by TBI severity, recurrence, and type of pathology, and also may be influenced by promptness of clinical intervention when more effective treatments become available. An important task is prevention of repetitive TBI, particularly when the patient is still symptomatic. For these reasons, the establishment of quantitative biological markers can serve to improve diagnosis and preventative or therapeutic management. In this study, we used a shock-tube model of blast TBI to determine whether manganese-enhanced magnetic resonance imaging (MEMRI) can serve as a tool to accurately and quantitatively diagnose mild-to-moderate blast TBI. Mice were subjected to a 30 psig blast and administered a single dose of MnCl2 intraperitoneally. Longitudinal T1-magnetic resonance imaging (MRI) performed at 6, 24, 48, and 72 h and at 14 and 28 days revealed a marked signal enhancement in the brain of mice exposed to blast, compared with sham controls, at nearly all time-points. Interestingly, when mice were protected with a polycarbonate body shield during blast exposure, the marked increase in contrast was prevented. We conclude that manganese uptake can serve as a quantitative biomarker for TBI and that MEMRI is a minimally-invasive quantitative approach that can aid in the accurate diagnosis and management of blast TBI. In addition, the prevention of the increased uptake of manganese by body protection strongly suggests that the exposure of an individual to blast risk could benefit from the design of improved body armor.
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Affiliation(s)
- Olga Rodriguez
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC
| | - Michele L. Schaefer
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Brock Wester
- Research and Exploratory Development Department, Johns Hopkins University, Applied Physics Laboratory, Laurel, Maryland
| | - Yi-Chien Lee
- Department of Oncology, Georgetown University Medical Center, Washington DC
| | - Nathan Boggs
- Research and Exploratory Development Department, Johns Hopkins University, Applied Physics Laboratory, Laurel, Maryland
| | - Howard A. Conner
- Research and Exploratory Development Department, Johns Hopkins University, Applied Physics Laboratory, Laurel, Maryland
| | - Andrew C. Merkle
- Research and Exploratory Development Department, Johns Hopkins University, Applied Physics Laboratory, Laurel, Maryland
| | - Stanley T. Fricke
- Pediatric and Integrative Systems Biology, George Washington University, Washington, DC
| | - Chris Albanese
- Department of Oncology, Georgetown University Medical Center, Washington DC
- Department of Pathology, Georgetown University Medical Center, Washington DC
| | - Vassilis E. Koliatsos
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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59
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Sawyer TW, Wang Y, Ritzel DV, Josey T, Villanueva M, Shei Y, Nelson P, Hennes G, Weiss T, Vair C, Fan C, Barnes J. High-Fidelity Simulation of Primary Blast: Direct Effects on the Head. J Neurotrauma 2016; 33:1181-93. [PMID: 26582146 DOI: 10.1089/neu.2015.3914] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The role of primary blast in blast-induced traumatic brain injury (bTBI) is controversial in part due to the technical difficulties of generating free-field blast conditions in the laboratory. The use of traditional shock tubes often results in artifacts, particularly of dynamic pressure, whereas the forces affecting the head are dependent on where the animal is placed relative to the tube, whether the exposure is whole-body or head-only, and on how the head is actually exposed to the insult (restrained or not). An advanced blast simulator (ABS) has been developed that enables high-fidelity simulation of free-field blastwaves, including sharply defined static and dynamic overpressure rise times, underpressures, and secondary shockwaves. Rats were exposed in head-only fashion to single-pulse blastwaves of 15 to 30 psi static overpressure. Head restraints were configured so as to eliminate concussive and minimize whiplash forces exerted on the head, as shown by kinematic analysis. No overt signs of trauma were present in the animals post-exposure. However, significant changes in brain 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) and neurofilament heavy chain levels were evident by 7 days. In contrast to most studies of primary blast-induced TBI (PbTBI), no elevation of glial fibrillary acidic protein (GFAP) levels was noted when head movement was minimized. The ABS described in this article enables the generation of shockwaves highly representative of free-field blast. The use of this technology, in concert with head-only exposure, minimized head movement, and the kinematic analysis of the forces exerted on the head provide convincing evidence that primary blast directly causes changes in brain function and that GFAP may not be an appropriate biomarker of PbTBI.
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Affiliation(s)
- Thomas W Sawyer
- 1 Defence Research & Development Canada , Medicine Hat, Alberta, Canada
| | - Yushan Wang
- 1 Defence Research & Development Canada , Medicine Hat, Alberta, Canada
| | | | - Tyson Josey
- 1 Defence Research & Development Canada , Medicine Hat, Alberta, Canada
| | - Mercy Villanueva
- 1 Defence Research & Development Canada , Medicine Hat, Alberta, Canada
| | - Yimin Shei
- 1 Defence Research & Development Canada , Medicine Hat, Alberta, Canada
| | - Peggy Nelson
- 1 Defence Research & Development Canada , Medicine Hat, Alberta, Canada
| | - Grant Hennes
- 1 Defence Research & Development Canada , Medicine Hat, Alberta, Canada
| | - Tracy Weiss
- 1 Defence Research & Development Canada , Medicine Hat, Alberta, Canada
| | - Cory Vair
- 1 Defence Research & Development Canada , Medicine Hat, Alberta, Canada
| | - Changyang Fan
- 3 Canada West Biosciences , Calgary, Alberta, Canada
| | - Julia Barnes
- 3 Canada West Biosciences , Calgary, Alberta, Canada
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60
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Stemper BD, Shah AS, Budde MD, Olsen CM, Glavaski-Joksimovic A, Kurpad SN, McCrea M, Pintar FA. Behavioral Outcomes Differ between Rotational Acceleration and Blast Mechanisms of Mild Traumatic Brain Injury. Front Neurol 2016; 7:31. [PMID: 27014184 PMCID: PMC4789366 DOI: 10.3389/fneur.2016.00031] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/29/2016] [Indexed: 11/20/2022] Open
Abstract
Mild traumatic brain injury (mTBI) can result from a number of mechanisms, including blunt impact, head rotational acceleration, exposure to blast, and penetration of projectiles. Mechanism is likely to influence the type, severity, and chronicity of outcomes. The objective of this study was to determine differences in the severity and time course of behavioral outcomes following blast and rotational mTBI. The Medical College of Wisconsin (MCW) Rotational Injury model and a shock tube model of primary blast injury were used to induce mTBI in rats and behavioral assessments were conducted within the first week, as well as 30 and 60 days following injury. Acute recovery time demonstrated similar increases over protocol-matched shams, indicating acute injury severity equivalence between the two mechanisms. Post-injury behavior in the elevated plus maze demonstrated differing trends, with rotationally injured rats acutely demonstrating greater activity, whereas blast-injured rats had decreased activity that developed at chronic time points. Similarly, blast-injured rats demonstrated trends associated with cognitive deficits that were not apparent following rotational injuries. These findings demonstrate that rotational and blast injury result in behavioral changes with different qualitative and temporal manifestations. Whereas rotational injury was characterized by a rapidly emerging phenotype consistent with behavioral disinhibition, blast injury was associated with emotional and cognitive differences that were not evident acutely, but developed later, with an anxiety-like phenotype still present in injured animals at our most chronic measurements.
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Affiliation(s)
- Brian D. Stemper
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Alok S. Shah
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Matthew D. Budde
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Christopher M. Olsen
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, WI, USA
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
| | | | - Shekar N. Kurpad
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Michael McCrea
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Frank A. Pintar
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
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61
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Guley NH, Rogers JT, Del Mar NA, Deng Y, Islam RM, D'Surney L, Ferrell J, Deng B, Hines-Beard J, Bu W, Ren H, Elberger AJ, Marchetta JG, Rex TS, Honig MG, Reiner A. A Novel Closed-Head Model of Mild Traumatic Brain Injury Using Focal Primary Overpressure Blast to the Cranium in Mice. J Neurotrauma 2016; 33:403-22. [PMID: 26414413 PMCID: PMC4761824 DOI: 10.1089/neu.2015.3886] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mild traumatic brain injury (TBI) from focal head impact is the most common form of TBI in humans. Animal models, however, typically use direct impact to the exposed dura or skull, or blast to the entire head. We present a detailed characterization of a novel overpressure blast system to create focal closed-head mild TBI in mice. A high-pressure air pulse limited to a 7.5 mm diameter area on the left side of the head overlying the forebrain is delivered to anesthetized mice. The mouse eyes and ears are shielded, and its head and body are cushioned to minimize movement. This approach creates mild TBI by a pressure wave that acts on the brain, with minimal accompanying head acceleration-deceleration. A single 20-psi blast yields no functional deficits or brain injury, while a single 25-40 psi blast yields only slight motor deficits and brain damage. By contrast, a single 50-60 psi blast produces significant visual, motor, and neuropsychiatric impairments and axonal damage and microglial activation in major fiber tracts, but no contusive brain injury. This model thus reproduces the widespread axonal injury and functional impairments characteristic of closed-head mild TBI, without the complications of systemic or ocular blast effects or head acceleration that typically occur in other blast or impact models of closed-skull mild TBI. Accordingly, our model provides a simple way to examine the biomechanics, pathophysiology, and functional deficits that result from TBI and can serve as a reliable platform for testing therapies that reduce brain pathology and deficits.
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Affiliation(s)
- Natalie H. Guley
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Joshua T. Rogers
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Nobel A. Del Mar
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Yunping Deng
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Rafiqul M. Islam
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Anatomy and Histology, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Lauren D'Surney
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Jessica Ferrell
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Bowei Deng
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Jessica Hines-Beard
- Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Ophthalmology and Visual Sciences, Vanderbilt University, Nashville, Tennessee
| | - Wei Bu
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Huiling Ren
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Andrea J. Elberger
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | | | - Tonia S. Rex
- Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Ophthalmology and Visual Sciences, Vanderbilt University, Nashville, Tennessee
| | - Marcia G. Honig
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Anton Reiner
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
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62
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Abstract
Posttraumatic epilepsy (PTE) is one of the most common and devastating complications of traumatic brain injury (TBI). Currently, the etiopathology and mechanisms of PTE are poorly understood and as a result, there is no effective treatment or means to prevent it. Antiepileptic drugs remain common preventive strategies in the management of TBI to control acute posttraumatic seizures and to prevent the development of PTE, although their efficacy in the latter case is disputed. Different strategies of PTE prophylaxis have been showing promise in preclinical models, but their translation to the clinic still remains elusive due in part to the variability of these models and the fact they do not recapitulate all complex pathologies associated with human TBI. TBI is a multifaceted disorder reflected in several potentially epileptogenic alterations in the brain, including mechanical neuronal and vascular damage, parenchymal and subarachnoid hemorrhage, subsequent toxicity caused by iron-rich hemoglobin breakdown products, and energy disruption resulting in secondary injuries, including excitotoxicity, gliosis, and neuroinflammation, often coexisting to a different degree. Several in vivo models have been developed to reproduce the acute TBI cascade of events, to reflect its anatomical pathologies, and to replicate neurological deficits. Although acute and chronic recurrent posttraumatic seizures are well-recognized phenomena in these models, there is only a limited number of studies focused on PTE. The most used mechanical TBI models with documented electroencephalographic and behavioral seizures with remote epileptogenesis include fluid percussion, controlled cortical impact, and weight-drop. This chapter describes the most popular models of PTE-induced TBI models, focusing on the controlled cortical impact and the fluid percussion injury models, the methods of behavioral and electroencephalogram seizure assessments, and other approaches to detect epileptogenic properties, and discusses their potential application for translational research.
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63
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The functional and structural changes in the basilar artery due to overpressure blast injury. J Cereb Blood Flow Metab 2015; 35:1950-6. [PMID: 26104291 PMCID: PMC4671114 DOI: 10.1038/jcbfm.2015.151] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 04/13/2015] [Accepted: 05/07/2015] [Indexed: 12/13/2022]
Abstract
Overpressure blast-wave induced brain injury (OBI) leads to progressive pathophysiologic changes resulting in a reduction in brain blood flow, blood brain barrier breakdown, edema, and cerebral ischemia. The aim of this study was to evaluate cerebral vascular function after single and repeated OBI. Male Sprague-Dawley rats were divided into three groups: Control (Naive), single OBI (30 psi peak pressure, 1 to 2 msec duration), and repeated (days 1, 4, and 7) OBI (r-OBI). Rats were killed 24 hours after injury and the basilar artery was isolated, cannulated, and pressurized (90 cm H2O). Vascular responses to potassium chloride (KCl) (30 to 100 mmol/L), endothelin-1 (10(-12) to 10(-7) mol/L), acetylcholine (ACh) (10(-10) to 10(-4) mol/L) and diethylamine-NONO-ate (DEA-NONO-ate) (10(-10) to 10(-4) mol/L) were evaluated. The OBI resulted in an increase in the contractile responses to endothelin and a decrease in the relaxant responses to ACh in both single and r-OBI groups. However, impaired DEA-NONO-ate-induced vasodilation and increased wall thickness to lumen ratio were observed only in the r-OBI group. The endothelin-1 type A (ET(A)) receptor and endothelial nitric oxide synthase (eNOS) immunoreactivity were significantly enhanced by OBI. These findings indicate that both single and r-OBI impairs cerebral vascular endothelium-dependent dilation, potentially a consequence of endothelial dysfunction and/or vascular remodelling in basilar arteries after OBI.
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Miyazaki H, Miyawaki H, Satoh Y, Saiki T, Kawauchi S, Sato S, Saitoh D. Thoracic shock wave injury causes behavioral abnormalities in mice. Acta Neurochir (Wien) 2015; 157:2111-20; discussion 2120. [PMID: 26489739 DOI: 10.1007/s00701-015-2613-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 10/09/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND Mild traumatic brain injury (mTBI) is caused by complex mechanisms of systemic, local and cerebral responses to blast exposure. However, the molecular mechanisms of cognitive impairment after exposure to blast waves are not clearly known. We tested the hypothesis that thoracic injury induced functional and morphological impairment in the brain, leading to behavioral abnormalities. METHODS Mice were exposed to laser-induced shock waves (LISWs) impacting the thorax and assessed for behavioral outcome at 7 and 28 days post injury. Hippocampus and lung were collected for histopathological analysis and gene expression profiling after injury. RESULTS Thoracic injury transiently decreased the heart rate, blood pressure, peripheral oxyhemoglobin saturation and cerebral blood flow immediately after LISW exposure. Although LISWs exposure caused pulmonary contusions, hemorrhage was not apparent in the brain. At 7 and 28 days after, the injured mice exhibited impaired short-term memory and depression-like behavior compared with controls. Histological assessments showed an increase in neuronal cell death after shock wave exposure, especially in the CA3 region of the hippocampus. Moreover, shock wave exposure altered the expression of functionally relevant genes in the hippocampus at 1 h and 1 day post injury. CONCLUSIONS Our findings indicate that the LISW-induced thoracic injury with no direct impact on the brain affected the hippocampal gene expression and led to morphological alterations, resulting in behavioral abnormalities. Therefore, body protection may be extremely important in the effective prevention against blast-induced alterations in brain function.
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Affiliation(s)
- Hiromi Miyazaki
- Division of Traumatology, Research Institute, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan.
| | - Hiroki Miyawaki
- Department of Traumatology and Critical Care Medicine, National Defense Medical College Hospital, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Yasushi Satoh
- Department of Anesthesiology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Takami Saiki
- Division of Traumatology, Research Institute, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Satoko Kawauchi
- Division of Biomedical Information Sciences, Research Institute, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Shunichi Sato
- Division of Biomedical Information Sciences, Research Institute, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
| | - Daizoh Saitoh
- Division of Traumatology, Research Institute, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, 359-8513, Japan
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Courtney A, Courtney M. The Complexity of Biomechanics Causing Primary Blast-Induced Traumatic Brain Injury: A Review of Potential Mechanisms. Front Neurol 2015; 6:221. [PMID: 26539158 PMCID: PMC4609847 DOI: 10.3389/fneur.2015.00221] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 10/05/2015] [Indexed: 11/13/2022] Open
Abstract
Primary blast-induced traumatic brain injury (bTBI) is a prevalent battlefield injury in recent conflicts, yet biomechanical mechanisms of bTBI remain unclear. Elucidating specific biomechanical mechanisms is essential to developing animal models for testing candidate therapies and for improving protective equipment. Three hypothetical mechanisms of primary bTBI have received the most attention. Because translational and rotational head accelerations are primary contributors to TBI from non-penetrating blunt force head trauma, the acceleration hypothesis suggests that blast-induced head accelerations may cause bTBI. The hypothesis of direct cranial transmission suggests that a pressure transient traverses the skull into the brain and directly injures brain tissue. The thoracic hypothesis of bTBI suggests that some combination of a pressure transient reaching the brain via the thorax and a vagally mediated reflex result in bTBI. These three mechanisms may not be mutually exclusive, and quantifying exposure thresholds (for blasts of a given duration) is essential for determining which mechanisms may be contributing for a level of blast exposure. Progress has been hindered by experimental designs, which do not effectively expose animal models to a single mechanism and by over-reliance on poorly validated computational models. The path forward should be predictive validation of computational models by quantitative confirmation with blast experiments in animal models, human cadavers, and biofidelic human surrogates over a range of relevant blast magnitudes and durations coupled with experimental designs, which isolate a single injury mechanism.
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Affiliation(s)
- Amy Courtney
- Exponent Engineering and Scientific Consulting, Philadelphia, PA, USA
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Ahmed F, Plantman S, Cernak I, Agoston DV. The Temporal Pattern of Changes in Serum Biomarker Levels Reveals Complex and Dynamically Changing Pathologies after Exposure to a Single Low-Intensity Blast in Mice. Front Neurol 2015; 6:114. [PMID: 26124743 PMCID: PMC4464198 DOI: 10.3389/fneur.2015.00114] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 05/05/2015] [Indexed: 01/05/2023] Open
Abstract
Time-dependent changes in blood-based protein biomarkers can help identify the pathological processes in blast-induced traumatic brain injury (bTBI), assess injury severity, and monitor disease progression. We obtained blood from control and injured mice (exposed to a single, low-intensity blast) at 2-h, 1-day, 1–week, and 1-month post-injury. We then determined the serum levels of biomarkers related to metabolism (4-HNE, HIF-1α, ceruloplasmin), vascular function (AQP1, AQP4, VEGF, vWF, Flk-1), inflammation (OPN, CINC1, fibrinogen, MIP-1a, OX-44, p38, MMP-8, MCP-1 CCR5, CRP, galectin-1), cell adhesion and the extracellular matrix (integrin α6, TIMP1, TIMP4, Ncad, connexin-43), and axonal (NF-H, Tau), neuronal (NSE, CK-BB) and glial damage (GFAP, S100β, MBP) at various post-injury time points. Our findings indicate that the exposure to a single, low-intensity blast results in metabolic and vascular changes, altered cell adhesion, and axonal and neuronal injury in the mouse model of bTBI. Interestingly, serum levels of several inflammatory and astroglial markers were either unchanged or elevated only during the acute and subacute phases of injury. Conversely, serum levels of the majority of biomarkers related to metabolic and vascular functions, cell adhesion, as well as neuronal and axonal damage remained elevated at the termination of the experiment (1 month), indicating long-term systemic and cerebral alterations due to blast. Our findings show that the exposure to a single, low-intensity blast induces complex pathological processes with distinct temporal profiles. Hence, monitoring serum biomarker levels at various post-injury time points may provide enhanced diagnostics in blast-related neurological and multi-system deficits.
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Affiliation(s)
- Farid Ahmed
- Department of Anatomy, Physiology and Genetics, Uniformed Services University , Bethesda, MD , USA
| | - Stefan Plantman
- Department of Neuroscience, Karolinska Institutet , Stockholm , Sweden
| | - Ibolja Cernak
- Faculty of Rehabilitation Medicine, Canadian Military and Veterans' Clinical Rehabilitation Research, University of Alberta , Edmonton, AB , Canada
| | - Denes V Agoston
- Department of Anatomy, Physiology and Genetics, Uniformed Services University , Bethesda, MD , USA ; Department of Neuroscience, Karolinska Institutet , Stockholm , Sweden
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Kabu S, Jaffer H, Petro M, Dudzinski D, Stewart D, Courtney A, Courtney M, Labhasetwar V. Blast-Associated Shock Waves Result in Increased Brain Vascular Leakage and Elevated ROS Levels in a Rat Model of Traumatic Brain Injury. PLoS One 2015; 10:e0127971. [PMID: 26024446 PMCID: PMC4449023 DOI: 10.1371/journal.pone.0127971] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 04/21/2015] [Indexed: 12/14/2022] Open
Abstract
Blast-associated shock wave-induced traumatic brain injury (bTBI) remains a persistent risk for armed forces worldwide, yet its detailed pathophysiology remains to be fully investigated. In this study, we have designed and characterized a laboratory-scale shock tube to develop a rodent model of bTBI. Our blast tube, driven by a mixture of oxygen and acetylene, effectively generates blast overpressures of 20–130 psi, with pressure-time profiles similar to those of free-field blast waves. We tested our shock tube for brain injury response to various blast wave conditions in rats. The results show that blast waves cause diffuse vascular brain damage, as determined using a sensitive optical imaging method based on the fluorescence signal of Evans Blue dye extravasation developed in our laboratory. Vascular leakage increased with increasing blast overpressures and mapping of the brain slices for optical signal intensity indicated nonhomogeneous damage to the cerebral vasculature. We confirmed vascular leakage due to disruption in the blood-brain barrier (BBB) integrity following blast exposure. Reactive oxygen species (ROS) levels in the brain also increased with increasing blast pressures and with time post-blast wave exposure. Immunohistochemical analysis of the brain sections analyzed at different time points post blast exposure demonstrated astrocytosis and cell apoptosis, confirming sustained neuronal injury response. The main advantages of our shock-tube design are minimal jet effect and no requirement for specialized equipment or facilities, and effectively generate blast-associated shock waves that are relevant to battle-field conditions. Overall data suggest that increased oxidative stress and BBB disruption could be the crucial factors in the propagation and spread of neuronal degeneration following blast injury. Further studies are required to determine the interplay between increased ROS activity and BBB disruption to develop effective therapeutic strategies that can prevent the resulting cascade of neurodegeneration.
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Affiliation(s)
- Shushi Kabu
- Lerner Research Institute, Department of Biomedical Engineering, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Hayder Jaffer
- Lerner Research Institute, Department of Biomedical Engineering, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Marianne Petro
- Lerner Research Institute, Department of Biomedical Engineering, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Dave Dudzinski
- Lerner Research Institute, Medical Device Solutions, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Desiree Stewart
- Lerner Research Institute, Department of Biomedical Engineering, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Amy Courtney
- BTG Research, Colorado Springs, Colorado, United States of America
| | - Michael Courtney
- BTG Research, Colorado Springs, Colorado, United States of America
| | - Vinod Labhasetwar
- Lerner Research Institute, Department of Biomedical Engineering, Cleveland Clinic, Cleveland, Ohio, United States of America
- * E-mail:
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68
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Reis C, Wang Y, Akyol O, Ho WM, Ii RA, Stier G, Martin R, Zhang JH. What's New in Traumatic Brain Injury: Update on Tracking, Monitoring and Treatment. Int J Mol Sci 2015; 16:11903-65. [PMID: 26016501 PMCID: PMC4490422 DOI: 10.3390/ijms160611903] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/04/2015] [Accepted: 05/06/2015] [Indexed: 12/11/2022] Open
Abstract
Traumatic brain injury (TBI), defined as an alteration in brain functions caused by an external force, is responsible for high morbidity and mortality around the world. It is important to identify and treat TBI victims as early as possible. Tracking and monitoring TBI with neuroimaging technologies, including functional magnetic resonance imaging (fMRI), diffusion tensor imaging (DTI), positron emission tomography (PET), and high definition fiber tracking (HDFT) show increasing sensitivity and specificity. Classical electrophysiological monitoring, together with newly established brain-on-chip, cerebral microdialysis techniques, both benefit TBI. First generation molecular biomarkers, based on genomic and proteomic changes following TBI, have proven effective and economical. It is conceivable that TBI-specific biomarkers will be developed with the combination of systems biology and bioinformation strategies. Advances in treatment of TBI include stem cell-based and nanotechnology-based therapy, physical and pharmaceutical interventions and also new use in TBI for approved drugs which all present favorable promise in preventing and reversing TBI.
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Affiliation(s)
- Cesar Reis
- Department of Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA 92354, USA.
| | - Yuechun Wang
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, 11041 Campus Street, Risley Hall, Room 219, Loma Linda, CA 92354, USA.
- Department of Physiology, School of Medicine, University of Jinan, Guangzhou 250012, China.
| | - Onat Akyol
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, 11041 Campus Street, Risley Hall, Room 219, Loma Linda, CA 92354, USA.
| | - Wing Mann Ho
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, 11041 Campus Street, Risley Hall, Room 219, Loma Linda, CA 92354, USA.
- Department of Neurosurgery, University Hospital Innsbruck, Tyrol 6020, Austria.
| | - Richard Applegate Ii
- Department of Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA 92354, USA.
| | - Gary Stier
- Department of Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA 92354, USA.
| | - Robert Martin
- Department of Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA 92354, USA.
| | - John H Zhang
- Department of Anesthesiology, Loma Linda University Medical Center, Loma Linda, CA 92354, USA.
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, 11041 Campus Street, Risley Hall, Room 219, Loma Linda, CA 92354, USA.
- Department of Neurosurgery, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA.
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Rathbone ATL, Tharmaradinam S, Jiang S, Rathbone MP, Kumbhare DA. A review of the neuro- and systemic inflammatory responses in post concussion symptoms: Introduction of the "post-inflammatory brain syndrome" PIBS. Brain Behav Immun 2015; 46:1-16. [PMID: 25736063 DOI: 10.1016/j.bbi.2015.02.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 02/08/2015] [Accepted: 02/09/2015] [Indexed: 12/22/2022] Open
Abstract
Post-concussion syndrome is an aggregate of symptoms that commonly present together after head injury. These symptoms, depending on definition, include headaches, dizziness, neuropsychiatric symptoms, and cognitive impairment. However, these symptoms are common, occurring frequently in non-head injured controls, leading some to question the existence of post-concussion syndrome as a unique syndrome. Therefore, some have attempted to explain post-concussion symptoms as post-traumatic stress disorder, as they share many similar symptoms and post-traumatic stress disorder does not require head injury. This explanation falls short as patients with post-concussion syndrome do not necessarily experience many key symptoms of post-traumatic stress disorder. Therefore, other explanations must be sought to explain the prevalence of post-concussion like symptoms in non-head injury patients. Many of the situations in which post-concussion syndrome like symptoms may be experienced such as infection and post-surgery are associated with systemic inflammatory responses, and even neuroinflammation. Post-concussion syndrome itself has a significant neuroinflammatory component. In this review we examine the evidence of neuroinflammation in post-concussion syndrome and the potential role systemic inflammation plays in post-concussion syndrome like symptoms. We conclude that given the overlap between these conditions and the role of inflammation in their etiologies, a new term, post-inflammatory brain syndromes (PIBS), is necessary to describe the common outcomes of many different inflammatory insults. The concept of post-concussion syndrome is in its evolution therefore, the new term post-inflammatory brain syndromes provides a better understanding of etiology of its wide-array of symptoms and the wide array of conditions they can be seen in.
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Affiliation(s)
| | - Surejini Tharmaradinam
- Division of Pediatric Neurology, Department of Pediatrics, McMaster Children's Hospital, Pediatric Neurology, MUMC 3A, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Shucui Jiang
- Division of Neurosurgery, Department of Surgery, and Hamilton Neurorestorative Group, McMaster University, HSC 4E15, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada
| | - Michel P Rathbone
- Department of Medicine, Division of Neurology, McMaster University - Juravinski Hospital, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada.
| | - Dinesh A Kumbhare
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Toronto, University Health Network - Toronto Rehab - University Centre, 550 University Ave, Toronto, Ontario M5G 2A2, Canada
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Kawa L, Arborelius UP, Yoshitake T, Kehr J, Hökfelt T, Risling M, Agoston D. Neurotransmitter Systems in a Mild Blast Traumatic Brain Injury Model: Catecholamines and Serotonin. J Neurotrauma 2015; 32:1190-9. [PMID: 25525686 DOI: 10.1089/neu.2014.3669] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Exposure to improvised explosive devices can result in a unique form of traumatic brain injury--blast-induced traumatic brain injury (bTBI). At the mild end of the spectrum (mild bTBI [mbTBI]), there are cognitive and mood disturbances. Similar symptoms have been observed in post-traumatic stress disorder caused by exposure to extreme psychological stress without physical injury. A role of the monoaminergic system in mood regulation and stress is well established but its involvement in mbTBI is not well understood. To address this gap, we used a rodent model of mbTBI and detected a decrease in immobility behavior in the forced swim test at 1 d post-exposure, coupled with an increase in climbing behavior, but not after 14 d or later, possibly indicating a transient increase in anxiety-like behavior. Using in situ hybridization, we found elevated messenger ribonucleic acid levels of both tyrosine hydroxylase and tryptophan hydroxylase 2 in the locus coeruleus and the dorsal raphe nucleus, respectively, as early as 2 h post-exposure. High-performance liquid chromatography analysis 1 d post-exposure primarily showed elevated noradrenaline levels in several forebrain regions. Taken together, we report that exposure to mild blast results in transient changes in both anxiety-like behavior and brain region-specific molecular changes, implicating the monoaminergic system in the pathobiology of mbTBI.
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Affiliation(s)
- Lizan Kawa
- 1 Department of Neuroscience, Karolinska Institutet , Stockholm, Sweden
| | - Ulf P Arborelius
- 1 Department of Neuroscience, Karolinska Institutet , Stockholm, Sweden
| | - Takashi Yoshitake
- 2 Department of Physiology and Pharmacology, Karolinska Institutet , Stockholm, Sweden
| | - Jan Kehr
- 2 Department of Physiology and Pharmacology, Karolinska Institutet , Stockholm, Sweden
| | - Tomas Hökfelt
- 1 Department of Neuroscience, Karolinska Institutet , Stockholm, Sweden
| | - Mårten Risling
- 1 Department of Neuroscience, Karolinska Institutet , Stockholm, Sweden
| | - Denes Agoston
- 3 Department of Anatomy, Physiology and Genetics, the Uniformed Services University , Bethesda, Maryland
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71
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Elder GA, Gama Sosa MA, De Gasperi R, Stone JR, Dickstein DL, Haghighi F, Hof PR, Ahlers ST. Vascular and inflammatory factors in the pathophysiology of blast-induced brain injury. Front Neurol 2015; 6:48. [PMID: 25852632 PMCID: PMC4360816 DOI: 10.3389/fneur.2015.00048] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 02/23/2015] [Indexed: 11/13/2022] Open
Abstract
Blast-related traumatic brain injury (TBI) has received much recent attention because of its frequency in the conflicts in Iraq and Afghanistan. This renewed interest has led to a rapid expansion of clinical and animal studies related to blast. In humans, high-level blast exposure is associated with a prominent hemorrhagic component. In animal models, blast exerts a variety of effects on the nervous system including vascular and inflammatory effects that can be seen with even low-level blast exposures which produce minimal or no neuronal pathology. Acutely, blast exposure in animals causes prominent vasospasm and decreased cerebral blood flow along with blood-brain barrier breakdown and increased vascular permeability. Besides direct effects on the central nervous system, evidence supports a role for a thoracically mediated effect of blast; whereby, pressure waves transmitted through the systemic circulation damage the brain. Chronically, a vascular pathology has been observed that is associated with alterations of the vascular extracellular matrix. Sustained microglial and astroglial reactions occur after blast exposure. Markers of a central and peripheral inflammatory response are found for sustained periods after blast injury and include elevation of inflammatory cytokines and other inflammatory mediators. At low levels of blast exposure, a microvascular pathology has been observed in the presence of an otherwise normal brain parenchyma, suggesting that the vasculature may be selectively vulnerable to blast injury. Chronic immune activation in brain following vascular injury may lead to neurobehavioral changes in the absence of direct neuronal pathology. Strategies aimed at preventing or reversing vascular damage or modulating the immune response may improve the chronic neuropsychiatric symptoms associated with blast-related TBI.
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Affiliation(s)
- Gregory A Elder
- Neurology Service, James J. Peters Department of Veterans Affairs Medical Center , Bronx, NY , USA ; Department of Psychiatry, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Department of Neurology, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Miguel A Gama Sosa
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center , Bronx, NY , USA
| | - Rita De Gasperi
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center , Bronx, NY , USA
| | - James Radford Stone
- Department of Radiology and Medical Imaging, University of Virginia , Charlottesville, VA , USA ; Department of Neurosurgery, University of Virginia , Charlottesville, VA , USA
| | - Dara L Dickstein
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Department of Geriatrics and Palliative Care, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Fatemeh Haghighi
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center , Bronx, NY , USA ; Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Patrick R Hof
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai , New York, NY , USA ; Department of Geriatrics and Palliative Care, Icahn School of Medicine at Mount Sinai , New York, NY , USA
| | - Stephen T Ahlers
- Department of Neurotrauma, Operational and Undersea Medicine Directorate, Naval Medical Research Center , Silver Spring, MD , USA
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Kochanek PM, Jackson TC. It might be time to let cooler heads prevail after mild traumatic brain injury or concussion. Exp Neurol 2015; 267:13-7. [PMID: 25732932 DOI: 10.1016/j.expneurol.2015.02.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 02/09/2015] [Indexed: 01/10/2023]
Affiliation(s)
- Patrick M Kochanek
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, 3550 Terrace Street, Pittsburgh, PA 15261, USA; Safar Center for Resuscitation Research, 3434 Fifth Avenue, Pittsburgh, PA 15260, USA.
| | - Travis C Jackson
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, 3550 Terrace Street, Pittsburgh, PA 15261, USA; Safar Center for Resuscitation Research, 3434 Fifth Avenue, Pittsburgh, PA 15260, USA.
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Miller AP, Shah AS, Aperi BV, Budde MD, Pintar FA, Tarima S, Kurpad SN, Stemper BD, Glavaski-Joksimovic A. Effects of blast overpressure on neurons and glial cells in rat organotypic hippocampal slice cultures. Front Neurol 2015; 6:20. [PMID: 25729377 PMCID: PMC4325926 DOI: 10.3389/fneur.2015.00020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 01/25/2015] [Indexed: 11/13/2022] Open
Abstract
Due to recent involvement in military conflicts, and an increase in the use of explosives, there has been an escalation in the incidence of blast-induced traumatic brain injury (bTBI) among US military personnel. Having a better understanding of the cellular and molecular cascade of events in bTBI is prerequisite for the development of an effective therapy that currently is unavailable. The present study utilized organotypic hippocampal slice cultures (OHCs) exposed to blast overpressures of 150 kPa (low) and 280 kPa (high) as an in vitro bTBI model. Using this model, we further characterized the cellular effects of the blast injury. Blast-evoked cell death was visualized by a propidium iodide (PI) uptake assay as early as 2 h post-injury. Quantification of PI staining in the cornu Ammonis 1 and 3 (CA1 and CA3) and the dentate gyrus regions of the hippocampus at 2, 24, 48, and 72 h following blast exposure revealed significant time dependent effects. OHCs exposed to 150 kPa demonstrated a slow increase in cell death plateauing between 24 and 48 h, while OHCs from the high-blast group exhibited a rapid increase in cell death already at 2 h, peaking at ~24 h post-injury. Measurements of lactate dehydrogenase release into the culture medium also revealed a significant increase in cell lysis in both low- and high-blast groups compared to sham controls. OHCs were fixed at 72 h post-injury and immunostained for markers against neurons, astrocytes, and microglia. Labeling OHCs with PI, neuronal, and glial markers revealed that the blast-evoked extensive neuronal death and to a lesser extent loss of glial cells. Furthermore, our data demonstrated activation of astrocytes and microglial cells in low- and high-blasted OHCs, which reached a statistically significant difference in the high-blast group. These data confirmed that our in vitro bTBI model is a useful tool for studying cellular and molecular changes after blast exposure.
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Affiliation(s)
- Anna P Miller
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Alok S Shah
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Brandy V Aperi
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Matthew D Budde
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Frank A Pintar
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Sergey Tarima
- Division of Biostatistics, Institute for Health and Society, Medical College of Wisconsin , Milwaukee, WI , USA
| | - Shekar N Kurpad
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Brian D Stemper
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
| | - Aleksandra Glavaski-Joksimovic
- Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, WI , USA ; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin , Milwaukee, WI , USA ; Clement J. Zablocki Veterans Affairs Medical Center , Milwaukee, WI , USA
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Newman AJ, Hayes SH, Rao AS, Allman BL, Manohar S, Ding D, Stolzberg D, Lobarinas E, Mollendorf JC, Salvi R. Low-cost blast wave generator for studies of hearing loss and brain injury: blast wave effects in closed spaces. J Neurosci Methods 2015; 242:82-92. [PMID: 25597910 DOI: 10.1016/j.jneumeth.2015.01.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 12/12/2014] [Accepted: 01/07/2015] [Indexed: 01/24/2023]
Abstract
BACKGROUND Military personnel and civilians living in areas of armed conflict have increased risk of exposure to blast overpressures that can cause significant hearing loss and/or brain injury. The equipment used to simulate comparable blast overpressures in animal models within laboratory settings is typically very large and prohibitively expensive. NEW METHOD To overcome the fiscal and space limitations introduced by previously reported blast wave generators, we developed a compact, low-cost blast wave generator to investigate the effects of blast exposures on the auditory system and brain. RESULTS The blast wave generator was constructed largely from off the shelf components, and reliably produced blasts with peak sound pressures of up to 198dB SPL (159.3kPa) that were qualitatively similar to those produced from muzzle blasts or explosions. Exposure of adult rats to 3 blasts of 188dB peak SPL (50.4kPa) resulted in significant loss of cochlear hair cells, reduced outer hair cell function and a decrease in neurogenesis in the hippocampus. COMPARISON TO EXISTING METHODS Existing blast wave generators are typically large, expensive, and are not commercially available. The blast wave generator reported here provides a low-cost method of generating blast waves in a typical laboratory setting. CONCLUSIONS This compact blast wave generator provides scientists with a low cost device for investigating the biological mechanisms involved in blast wave injury to the rodent cochlea and brain that may model many of the damaging effects sustained by military personnel and civilians exposed to intense blasts.
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Affiliation(s)
- Andrew J Newman
- Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Sarah H Hayes
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Abhiram S Rao
- Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Brian L Allman
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Senthilvelan Manohar
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Dalian Ding
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Daniel Stolzberg
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Edward Lobarinas
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Joseph C Mollendorf
- Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Richard Salvi
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
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75
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Elder GA, Stone JR, Ahlers ST. Effects of low-level blast exposure on the nervous system: is there really a controversy? Front Neurol 2014; 5:269. [PMID: 25566175 PMCID: PMC4271615 DOI: 10.3389/fneur.2014.00269] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 11/29/2014] [Indexed: 12/20/2022] Open
Abstract
High-pressure blast waves can cause extensive CNS injury in human beings. However, in combat settings, such as Iraq and Afghanistan, lower level exposures associated with mild traumatic brain injury (mTBI) or subclinical exposure have been much more common. Yet controversy exists concerning what traits can be attributed to low-level blast, in large part due to the difficulty of distinguishing blast-related mTBI from post-traumatic stress disorder (PTSD). We describe how TBI is defined in human beings and the problems posed in using current definitions to recognize blast-related mTBI. We next consider the problem of applying definitions of human mTBI to animal models, in particular that TBI severity in human beings is defined in relation to alteration of consciousness at the time of injury, which typically cannot be assessed in animals. However, based on outcome assessments, a condition of "low-level" blast exposure can be defined in animals that likely approximates human mTBI or subclinical exposure. We review blast injury modeling in animals noting that inconsistencies in experimental approach have contributed to uncertainty over the effects of low-level blast. Yet, animal studies show that low-level blast pressure waves are transmitted to the brain. In brain, low-level blast exposures cause behavioral, biochemical, pathological, and physiological effects on the nervous system including the induction of PTSD-related behavioral traits in the absence of a psychological stressor. We review the relationship of blast exposure to chronic neurodegenerative diseases noting the paradoxical lowering of Abeta by blast, which along with other observations suggest that blast-related TBI is pathophysiologically distinct from non-blast TBI. Human neuroimaging studies show that blast-related mTBI is associated with a variety of chronic effects that are unlikely to be explained by co-morbid PTSD. We conclude that abundant evidence supports low-level blast as having long-term effects on the nervous system.
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Affiliation(s)
- Gregory A. Elder
- Neurology Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - James R. Stone
- Department of Radiology, University of Virginia, Charlottesville, VA, USA
- Department of Neurosurgery, University of Virginia, Charlottesville, VA, USA
| | - Stephen T. Ahlers
- Department of Neurotrauma, Operational and Undersea Medicine Directorate, Naval Medical Research Center, Silver Spring, MD, USA
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76
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Wang Y, Arun P, Wei Y, Oguntayo S, Gharavi R, Valiyaveettil M, Nambiar MP, Long JB. Repeated blast exposures cause brain DNA fragmentation in mice. J Neurotrauma 2014; 31:498-504. [PMID: 24074345 DOI: 10.1089/neu.2013.3074] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The pathophysiology of blast-induced traumatic brain injury (TBI) and subsequent behavioral deficits are not well understood. Unraveling the mechanisms of injury is critical to derive effective countermeasures against this form of neurotrauma. Preservation of the integrity of cellular DNA is crucial for the function and survival of cells. We evaluated the effect of repeated blast exposures on the integrity of brain DNA and tested the utility of cell-free DNA (CFD) in plasma as a biomarker for the diagnosis and prognosis of blast-induced polytrauma. The results revealed time-dependent breakdown in cellular DNA in different brain regions, with the maximum damage at 24 h post-blast exposures. CFD levels in plasma showed a significant transient increase, which was largely independent of the timing and severity of brain DNA damage; maximum levels were recorded at 2 h after repeated blast exposure and returned to baseline at 24 h. A positive correlation was observed between the righting reflex time and CFD level in plasma at 2 h after blast exposure. Brain DNA damage subsequent to repeated blast was associated with decreased mitochondrial membrane potential, increased release of cytochrome C, and up-regulation of caspase-3, all of which are indicative of cellular apoptosis. Shock-wave-induced DNA damage and initiation of mitochondrial-driven cellular apoptosis in the brain after repeated blast exposures indicate that therapeutic strategies directed toward inhibition of DNA damage or instigation of DNA repair may be effective countermeasures.
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Affiliation(s)
- Ying Wang
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research , Silver Spring, Maryland
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Cernak I, Wing ID, Davidsson J, Plantman S. A novel mouse model of penetrating brain injury. Front Neurol 2014; 5:209. [PMID: 25374559 PMCID: PMC4205813 DOI: 10.3389/fneur.2014.00209] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 09/30/2014] [Indexed: 02/06/2023] Open
Abstract
Penetrating traumatic brain injury (pTBI) has been difficult to model in small laboratory animals, such as rats or mice. Previously, we have established a non-fatal, rat model for pTBI using a modified air-rifle that accelerates a pellet, which hits a small probe that then penetrates the experimental animal’s brain. Knockout and transgenic strains of mice offer attractive tools to study biological reactions induced by TBI. Hence, in the present study, we adapted and modified our model to be used with mice. The technical characterization of the impact device included depth and speed of impact, as well as dimensions of the temporary cavity formed in a brain surrogate material after impact. Biologically, we have focused on three distinct levels of severity (mild, moderate, and severe), and characterized the acute phase response to injury in terms of tissue destruction, neural degeneration, and gliosis. Functional outcome was assessed by measuring bodyweight and motor performance on rotarod. The results showed that this model is capable of reproducing major morphological and neurological changes of pTBI; as such, we recommend its utilization in research studies aiming to unravel the biological events underlying injury and regeneration after pTBI.
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Affiliation(s)
- Ibolja Cernak
- Military and Veterans' Clinical Rehabilitation Research, University of Alberta , Edmonton, AB , Canada
| | - Ian D Wing
- Johns Hopkins University Applied Physics Laboratory , Laurel, MD , USA
| | - Johan Davidsson
- Division of Vehicle Safety, Chalmers University of Technology , Göteborg , Sweden
| | - Stefan Plantman
- Department of Neuroscience, Karolinska Institutet , Stockholm , Sweden
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78
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Gandy S, Ikonomovic MD, Mitsis E, Elder G, Ahlers ST, Barth J, Stone JR, DeKosky ST. Chronic traumatic encephalopathy: clinical-biomarker correlations and current concepts in pathogenesis. Mol Neurodegener 2014; 9:37. [PMID: 25231386 PMCID: PMC4249716 DOI: 10.1186/1750-1326-9-37] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 05/13/2014] [Indexed: 12/14/2022] Open
Abstract
Background Chronic traumatic encephalopathy (CTE) is a recently revived term used to describe a neurodegenerative process that occurs as a long term complication of repetitive mild traumatic brain injury (TBI). Corsellis provided one of the classic descriptions of CTE in boxers under the name “dementia pugilistica” (DP). Much recent attention has been drawn to the apparent association of CTE with contact sports (football, soccer, hockey) and with frequent battlefield exposure to blast waves generated by improvised explosive devices (IEDs). Recently, a promising serum biomarker has been identified by measurement of serum levels of the neuronal microtubule associated protein tau. New positron emission tomography (PET) ligands (e.g., [18 F] T807) that identify brain tauopathy have been successfully deployed for the in vitro and in vivo detection of presumptive tauopathy in the brains of subjects with clinically probable CTE. Methods Major academic and lay publications on DP/CTE were reviewed beginning with the 1928 paper describing the initial use of the term CTE by Martland. Results The major current concepts in the neurological, psychiatric, neuropsychological, neuroimaging, and body fluid biomarker science of DP/CTE have been summarized. Newer achievements, such as serum tau and [18 F] T807 tauopathy imaging, are also introduced and their significance has been explained. Conclusion Recent advances in the science of DP/CTE hold promise for elucidating a long sought accurate determination of the true prevalence of CTE. This information holds potentially important public health implications for estimating the risk of contact sports in inflicting permanent and/or progressive brain damage on children, adolescents, and adults.
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Affiliation(s)
- Sam Gandy
- Departments of Neurology, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, New York, NY 10029, USA.
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79
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Jiang Y, Pagadala J, Miller DD, Steinle JJ. Insulin-like growth factor-1 binding protein 3 (IGFBP-3) promotes recovery from trauma-induced expression of inflammatory and apoptotic factors in retina. Cytokine 2014; 70:115-9. [PMID: 25082650 DOI: 10.1016/j.cyto.2014.07.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 06/28/2014] [Accepted: 07/07/2014] [Indexed: 11/28/2022]
Abstract
Ocular trauma affects 20% of Americans in their lifetime and can cause permanent visual system damage. We have used a mouse model of ocular trauma (exposure to an air blast from a paintball gun) to examine pathways that trigger the resulting retinal damage and to develop treatment strategies that might ameliorate the deleterious effects of trauma on retinal tissue. Our previous studies have shown that ocular blast causes an increase in protein levels of inflammatory mediators and apoptotic factors, including tumor necrosis factor alpha (TNFα) and interleukin-1-beta (IL-1β), as well as the apoptotic markers, Bax, cytochrome C, and cleaved caspase 3. Furthermore, topical treatment by eye drop application of a β-adrenergic receptor agonist, Compound 49b, was shown to decrease these inflammation/apoptosis markers and thus ameliorate the effects of blast trauma. We postulate that the protective effect of Compound 49b may be linked to its demonstrated ability to activate the β-adrenergic receptor and in turn trigger production of insulin-like growth factor binding protein 3 (IGFBP-3). In the current study, we tested this hypothesis using mice with minimal IGFBP-3 activity (IGFBP-3 knockdown mouse) vs. wildtype mice. We found that ocular blast alone did not affect IGFBP-3 levels in retinas of wild type or knockdown mice and surprisingly, the lower levels of IGFBP-3 in knockdown animals did not exacerbate the blast-induced increase in protein levels of inflammation/apoptosis markers. Nevertheless, the levels of IGFBP-3 were significantly increased in knockdown mouse retina by treatment with Compound 49b 24h post-trauma and as expected, the increase in IGFBP-3 was linked to a decrease in inflammation/apoptosis markers. We conclude that while lowered IGFBP-3 may not make the retina more vulnerable to blast injury, an increase in IGFBP-3 post-trauma may play an important role in limiting trauma-induced inflammatory and apoptotic pathways leading to retinal damage. Eye drop application of the β-adrenergic receptor agonist, Compound 49b, provides a promising treatment strategy for increasing IGFBP-3 levels to promote recovery from retinal inflammation and apoptosis after ocular blast.
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Affiliation(s)
- Youde Jiang
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Jayaprakash Pagadala
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Duane D Miller
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Jena J Steinle
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, United States; Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, United States; Department of Anatomy & Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States.
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80
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Gama Sosa MA, De Gasperi R, Janssen PL, Yuk FJ, Anazodo PC, Pricop PE, Paulino AJ, Wicinski B, Shaughness MC, Maudlin-Jeronimo E, Hall AA, Dickstein DL, McCarron RM, Chavko M, Hof PR, Ahlers ST, Elder GA. Selective vulnerability of the cerebral vasculature to blast injury in a rat model of mild traumatic brain injury. Acta Neuropathol Commun 2014; 2:67. [PMID: 24938728 PMCID: PMC4229875 DOI: 10.1186/2051-5960-2-67] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 06/03/2014] [Indexed: 12/23/2022] Open
Abstract
Background Blast-related traumatic brain injury (TBI) is a common cause of injury in the military operations in Iraq and Afghanistan. How the primary blast wave affects the brain is not well understood. The aim of the present study was to examine whether blast exposure affects the cerebral vasculature in a rodent model. We analyzed the brains of rats exposed to single or multiple (three) 74.5 kPa blast exposures, conditions that mimic a mild TBI. Rats were sacrificed 24 hours or between 6 and 10 months after exposure. Blast-induced cerebral vascular pathology was examined by a combination of light microscopy, immunohistochemistry, and electron microscopy. Results We describe a selective vascular pathology that is present acutely at 24 hours after injury. The vascular pathology is found at the margins of focal shear-related injuries that, as we previously showed, typically follow the patterns of penetrating cortical vessels. However, changes in the microvasculature extend beyond the margins of such lesions. Electron microscopy revealed that microvascular pathology is found in regions of the brain with an otherwise normal neuropil. This initial injury leads to chronic changes in the microvasculature that are still evident many months after the initial blast exposure. Conclusions These studies suggest that vascular pathology may be a central mechanism in the induction of chronic blast-related injury.
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81
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Simard JM, Pampori A, Keledjian K, Tosun C, Schwartzbauer G, Ivanova S, Gerzanich V. Exposure of the thorax to a sublethal blast wave causes a hydrodynamic pulse that leads to perivenular inflammation in the brain. J Neurotrauma 2014; 31:1292-304. [PMID: 24673157 DOI: 10.1089/neu.2013.3016] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Traumatic brain injury (TBI) caused by an explosive blast (blast-TBI) is postulated to result, in part, from transvascular transmission to the brain of a hydrodynamic pulse (a.k.a., volumetric blood surge, ballistic pressure wave, hydrostatic shock, or hydraulic shock) induced in major intrathoracic blood vessels. This mechanism of blast-TBI has not been demonstrated directly. We tested the hypothesis that a blast wave impacting the thorax would induce a hydrodynamic pulse that would cause pathological changes in the brain. We constructed a Thorax-Only Blast Injury Apparatus (TOBIA) and a Jugular-Only Blast Injury Apparatus (JOBIA). TOBIA delivered a collimated blast wave to the right lateral thorax of a rat, precluding direct impact on the cranium. JOBIA delivered a blast wave to the fluid-filled port of an extracorporeal intravenous infusion device whose catheter was inserted retrograde into the jugular vein, precluding lung injury. Long Evans rats were subjected to sublethal injury by TOBIA or JOBIA. Blast injury induced by TOBIA was characterized by apnea and diffuse bilateral hemorrhagic injury to the lungs associated with a transient reduction in pulse oximetry signals. Immunolabeling 24 h after injury by TOBIA showed up-regulation of tumor necrosis factor alpha, ED-1, sulfonylurea receptor 1 (Sur1), and glial fibrillary acidic protein in veins or perivenular tissues and microvessels throughout the brain. The perivenular inflammatory effects induced by TOBIA were prevented by ligating the jugular vein and were reproduced using JOBIA. We conclude that blast injury to the thorax leads to perivenular inflammation, Sur1 up-regulation, and reactive astrocytosis resulting from the induction of a hydrodynamic pulse in the vasculature.
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Affiliation(s)
- J Marc Simard
- 1 Department of Neurosurgery, University of Maryland School of Medicine , Baltimore, Maryland
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82
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Endothelial Activation and Chemoattractant Expression are Early Processes in Isolated Blast Brain Injury. Neuromolecular Med 2014; 16:606-19. [DOI: 10.1007/s12017-014-8313-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 05/14/2014] [Indexed: 01/03/2023]
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83
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Huber BR, Meabon JS, Martin TJ, Mourad PD, Bennett R, Kraemer BC, Cernak I, Petrie EC, Emery MJ, Swenson ER, Mayer C, Mehic E, Peskind ER, Cook DG. Blast exposure causes early and persistent aberrant phospho- and cleaved-tau expression in a murine model of mild blast-induced traumatic brain injury. J Alzheimers Dis 2014; 37:309-23. [PMID: 23948882 DOI: 10.3233/jad-130182] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mild traumatic brain injury (mTBI) is considered the 'signature injury' of combat veterans that have served during the wars in Iraq and Afghanistan. This prevalence of mTBI is due in part to the common exposure to high explosive blasts in combat zones. In addition to the threats of blunt impact trauma caused by flying objects and the head itself being propelled against objects, the primary blast overpressure (BOP) generated by high explosives is capable of injuring the brain. Compared to other means of causing TBI, the pathophysiology of mild-to-moderate BOP is less well understood. To study the consequences of BOP exposure in mice, we employed a well-established approach using a compressed gas-driven shock tube that recapitulates battlefield-relevant open-field BOP. We found that 24 hours post-blast a single mild BOP provoked elevation of multiple phospho- and cleaved-tau species in neurons, as well as elevating manganese superoxide-dismutase (MnSOD or SOD2) levels, a cellular response to oxidative stress. In hippocampus, aberrant tau species persisted for at least 30 days post-exposure, while SOD2 levels returned to sham control levels. These findings suggest that elevated phospho- and cleaved-tau species may be among the initiating pathologic processes induced by mild blast exposure. These findings may have important implications for efforts to prevent blast-induced insults to the brain from progressing into long-term neurodegenerative disease processes.
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Affiliation(s)
- Bertrand R Huber
- Northwest Network Mental Illness, Research, Education, and Clinical Center (MIRECC), Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
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84
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Li BC, Li Y, Xu C, Wang J, Chen Z, Li G, Zhang J, Hu S, Wang L, Feng H. Blast-induced traumatic brain injury of goats in confined space. Neurol Res 2014; 36:974-82. [PMID: 24730755 DOI: 10.1179/1743132813y.0000000314] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVE To study blast-induced traumatic brain injury (bTBI) characteristics in confined space. METHODS The goats were placed at the column-like buildings with trinitrotoluene (TNT) as the source of the blast wave. The pressure was recorded at 2-8 m from the explosion center. The systemic physiology, electroencephalogram (EEG), serum level of S-100beta, and neuron specific enolase (NSE) were determined pre and post the exposure. Neuroanatomy and neuropathology were observed 4 hours after the exposure. RESULTS The blast waveform was composed of two peaks from the incident and reflection wave with a range of pressure-duration from 555/913 kPa-0.663 milliseconds at 2 m to 45/71 kPa-2.7/2.367 milliseconds at 8 m. At 2 m, the goats experienced brain depression while the heart rate and respiratory rate concomitantly increased with bloody foam fluid emission from the nose and the mouth. Of the goats, 88.89% were burned. The distinctive gross neuroanatomical changes were congestive expansion of surface vessels on the hemisphere cerebellum and brainstem along with subarachnoid hemorrhage on the frontal lobe, mesencephalon, and brainstem. Subarachnoid hemorrhage, enlarged perivascular space, vascular dilatation and congestion, and parenchymal hemorrhagic could be easily observed microscopically. High amplitude and low frequency of waveforms appeared in the EEG. The serum concentration of S-100beta and NSE were elevated. Although these pathophysiological changes diminished with increasing distance from the explosive center, these changes existed for the 8 m subjects. CONCLUSIONS Blast-induced traumatic brain injury can be induced by a complex blast wave with a pressure and duration of 45/71 kPa and 2.7/2.367 milliseconds. Its severity is related to the features and waveforms of the blast.
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Valiyaveettil M, Alamneh YA, Wang Y, Arun P, Oguntayo S, Wei Y, Long JB, Nambiar MP. Cytoskeletal protein α-II spectrin degradation in the brain of repeated blast exposed mice. Brain Res 2014; 1549:32-41. [PMID: 24412202 DOI: 10.1016/j.brainres.2013.12.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 12/20/2013] [Accepted: 12/24/2013] [Indexed: 10/25/2022]
Abstract
Repeated blast exposures commonly induce traumatic brain injury (TBI) characterized by diffuse axonal injury (DAI). We hypothesized that degradation of cytoskeletal proteins in the brain can lead to DAI, and evaluated α-II spectrin degradation in the pathophysiology of blast-induced TBI using the tightly-coupled three repetitive blast exposure mice model with a 1-30 min window in between exposures. Degradation of α-II spectrin and the expression profiles of caspase-3 and calpain-2, the major enzymes involved in the degradation were analyzed in the frontal cortex and cerebellum using Western blotting with specific antibodies. DAI at different brain regions was evaluated by neuropathology with silver staining. Repeated blast exposures resulted in significant increases in the α-II spectrin degradation products in the frontal cortex and cerebellum compared to sham controls. Expression of active caspase-3, which degrades α-II spectrin, showed significant increase in the frontal cortex after blast exposure at all the time points studied, while cerebellum showed an acute increase which was normalized over time. The expression of another α-II spectrin degrading enzyme, calpain-2, showed a rapid increase in the frontal cortex after blast exposure and it was significantly higher in the cerebellum at later time points. Neuropathological analysis showed significant levels of DAI at the frontal cortex and cerebellum at multiple time points after repeated blast injury. In summary, repeated blast exposure results in specific degradation of α-II spectrin in the brain along with differential expression of caspase-3/calpain-2 suggesting cytoskeletal breakdown as a possible contributor of DAI after repeated blast exposure.
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Affiliation(s)
- Manoj Valiyaveettil
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
| | - Yonas A Alamneh
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Ying Wang
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Peethambaran Arun
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Samuel Oguntayo
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Yanling Wei
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Joseph B Long
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Madhusoodana P Nambiar
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
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Kobeissy F, Mondello S, Tümer N, Toklu HZ, Whidden MA, Kirichenko N, Zhang Z, Prima V, Yassin W, Anagli J, Chandra N, Svetlov S, Wang KKW. Assessing neuro-systemic & behavioral components in the pathophysiology of blast-related brain injury. Front Neurol 2013; 4:186. [PMID: 24312074 PMCID: PMC3836009 DOI: 10.3389/fneur.2013.00186] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 11/02/2013] [Indexed: 01/10/2023] Open
Abstract
Among the U.S. military personnel, blast injury is among the leading causes of brain injury. During the past decade, it has become apparent that even blast injury as a form of mild traumatic brain injury (mTBI) may lead to multiple different adverse outcomes, such as neuropsychiatric symptoms and long-term cognitive disability. Blast injury is characterized by blast overpressure, blast duration, and blast impulse. While the blast injuries of a victim close to the explosion will be severe, majority of victims are usually at a distance leading to milder form described as mild blast TBI (mbTBI). A major feature of mbTBI is its complex manifestation occurring in concert at different organ levels involving systemic, cerebral, neuronal, and neuropsychiatric responses; some of which are shared with other forms of brain trauma such as acute brain injury and other neuropsychiatric disorders such as post-traumatic stress disorder. The pathophysiology of blast injury exposure involves complex cascades of chronic psychological stress, autonomic dysfunction, and neuro/systemic inflammation. These factors render blast injury as an arduous challenge in terms of diagnosis and treatment as well as identification of sensitive and specific biomarkers distinguishing mTBI from other non-TBI pathologies and from neuropsychiatric disorders with similar symptoms. This is due to the “distinct” but shared and partially identified biochemical pathways and neuro-histopathological changes that might be linked to behavioral deficits observed. Taken together, this article aims to provide an overview of the current status of the cellular and pathological mechanisms involved in blast overpressure injury and argues for the urgent need to identify potential biomarkers that can hint at the different mechanisms involved.
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Affiliation(s)
- Firas Kobeissy
- Department of Psychiatry, Center of Neuroproteomics & Biomarker Research, University of Florida , Gainesville, FL , USA ; Department of Biochemistry and Molecular Genetics, American University of Beirut Medical Center , Beirut , Lebanon
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87
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Adenosine A2A receptor deficiency alleviates blast-induced cognitive dysfunction. J Cereb Blood Flow Metab 2013; 33:1789-98. [PMID: 23921902 PMCID: PMC3824177 DOI: 10.1038/jcbfm.2013.127] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 07/06/2013] [Accepted: 07/09/2013] [Indexed: 11/09/2022]
Abstract
Traumatic brain injury (TBI), particularly explosive blast-induced TBI (bTBI), has become the most prevalent injury among military personnel. The disruption of cognitive function is one of the most serious consequences of bTBI because its long-lasting effects prevent survivors fulfilling their active duty and resuming normal civilian life. However, the mechanisms are poorly understood and there is no treatment available. This study investigated the effects of adenosine A2A receptor (A2AR) on bTBI-induced cognitive deficit, and explored the underlying mechanisms. After being subjected to moderate whole-body blast injury, mice lacking the A2AR (A2AR knockout (KO)) showed less severity and shorter duration of impaired spatial reference memory and working memory than wild-type mice did. In addition, bTBI-induced cortical and hippocampal lesions, as well as proinflammatory cytokine expression, glutamate release, edema, cell loss, and gliosis in both early and prolonged phases of the injury, were significantly attenuated in A2AR KO mice. The results suggest that early injury and chronic neuropathological damages are important mechanisms of bTBI-induced cognitive impairment, and that the impairment can be attenuated by preventing A2AR activation. These findings suggest that A2AR antagonism is a potential therapeutic strategy for mild-to-moderate bTBI and consequent cognitive impairment.
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88
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Yeh PH, Wang B, Oakes TR, French LM, Pan H, Graner J, Liu W, Riedy G. Postconcussional disorder and PTSD symptoms of military-related traumatic brain injury associated with compromised neurocircuitry. Hum Brain Mapp 2013; 35:2652-73. [PMID: 24038816 DOI: 10.1002/hbm.22358] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 04/23/2013] [Accepted: 06/13/2013] [Indexed: 11/09/2022] Open
Abstract
Traumatic brain injury (TBI) is a common combat injury, often through explosive blast, and produces heterogeneous brain changes due to various mechanisms of injury. It is unclear whether the vulnerability of white matter differs between blast and impact injury, and the consequences of microstructural changes on neuropsychological function are poorly understood in military TBI patients. Diffusion tensor imaging (DTI) techniques were used to assess the neurocircuitry in 37 U.S. service members (29 mild, 7 moderate, 1 severe; 17 blast and 20 nonblast), who sustained a TBI while deployed, compared to 14 nondeployed, military controls. High-dimensional deformable registration of MRI diffusion tensor data was followed by fiber tracking and tract-specific analysis along with region-of-interest analysis. DTI results were examined in relation to post-concussion and post-traumatic stress disorder (PTSD) symptoms. The most prominent white matter microstructural injury for both blast and nonblast patients was in the frontal fibers within the fronto-striatal (corona radiata, internal capsule) and fronto-limbic circuits (fornix, cingulum), the fronto-parieto-occipital association fibers, in brainstem fibers, and in callosal fibers. Subcortical superior-inferiorly oriented tracts were more vulnerable to blast injury than nonblast injury, while direct impact force had more detrimental effects on anterior-posteriorly oriented tracts, which tended to cause heterogeneous left and right hemispheric asymmetries of white matter connectivity. The tractography using diffusion anisotropy deficits revealed the cortico-striatal-thalamic-cerebellar-cortical (CSTCC) networks, where increased post-concussion and PTSD symptoms were associated with low fractional anisotropy in the major nodes of compromised CSTCC neurocircuitry, and the consequences on cognitive function were explored as well.
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Affiliation(s)
- Ping-Hong Yeh
- Traumatic Brain Injury Image Analysis Lab, Department of Radiology, Henry Jackson Foundation for the Advancement of Military Medicine, Rockville, Maryland
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Sosa MAG, De Gasperi R, Paulino AJ, Pricop PE, Shaughness MC, Maudlin-Jeronimo E, Hall AA, Janssen WGM, Yuk FJ, Dorr NP, Dickstein DL, McCarron RM, Chavko M, Hof PR, Ahlers ST, Elder GA. Blast overpressure induces shear-related injuries in the brain of rats exposed to a mild traumatic brain injury. Acta Neuropathol Commun 2013; 1:51. [PMID: 24252601 PMCID: PMC3893550 DOI: 10.1186/2051-5960-1-51] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 08/06/2013] [Indexed: 01/22/2023] Open
Abstract
Background Blast-related traumatic brain injury (TBI) has been a significant cause of injury in the military operations of Iraq and Afghanistan, affecting as many as 10-20% of returning veterans. However, how blast waves affect the brain is poorly understood. To understand their effects, we analyzed the brains of rats exposed to single or multiple (three) 74.5 kPa blast exposures, conditions that mimic a mild TBI. Results Rats were sacrificed 24 hours or between 4 and 10 months after exposure. Intraventricular hemorrhages were commonly observed after 24 hrs. A screen for neuropathology did not reveal any generalized histopathology. However, focal lesions resembling rips or tears in the tissue were found in many brains. These lesions disrupted cortical organization resulting in some cases in unusual tissue realignments. The lesions frequently appeared to follow the lines of penetrating cortical vessels and microhemorrhages were found within some but not most acute lesions. Conclusions These lesions likely represent a type of shear injury that is unique to blast trauma. The observation that lesions often appeared to follow penetrating cortical vessels suggests a vascular mechanism of injury and that blood vessels may represent the fault lines along which the most damaging effect of the blast pressure is transmitted.
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90
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Jiang Y, Liu L, Pagadala J, Miller DD, Steinle JJ. Compound 49b protects against blast-induced retinal injury. J Neuroinflammation 2013; 10:96. [PMID: 23899290 PMCID: PMC3751549 DOI: 10.1186/1742-2094-10-96] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 07/26/2013] [Indexed: 11/10/2022] Open
Abstract
AIM To determine whether Compound 49b, a novel beta-adrenergic receptor agonist, can prevent increased inflammation and apoptosis in mice after exposure to ocular blast. METHODS Eyes of C57/BL6 mice were exposed to a blast of air from a paintball gun at 26 psi (≈0.18 MPa). Eyes were collected 4 hours, 24 hours, and 72 hours after blast exposure. In a subset of mice, Compound 49b eyedrops (1 mM) were applied within 4 hours, 24 hours, or 72 hours of the blast. Three days after blast exposure, all mice were sacrificed. One eye was used to measure levels of retinal proteins (TNFα, IL-1β, Bax, BcL-xL, caspase 3, and cytochrome C). The other eye was used for TUNEL labeling of apoptotic cells, which were co-labeled with NeuN to stain for retinal ganglion cells. RESULTS We found that ocular exposure to 26 psi air pressure led to a significant increase in levels of apoptotic and inflammatory mediators within 4 hours, which lasted throughout the period investigated. When Compound 49b was applied within 4 hours or 24 hours of blast injury, levels of apoptotic and inflammatory mediators were significantly reduced. Application of Compound 49b within 72 hours of blast injury reduced levels of inflammatory mediators, but not to untreated levels. CONCLUSIONS Ocular blast injury produces a significant increase in levels of key inflammatory and apoptotic markers in the retina as early as 4 hours after blast exposure. These levels are significantly reduced if a beta-adrenergic receptor agonist is applied within 24 hours of blast exposure. Data suggest that local application of beta-adrenergic receptor agonists may be beneficial to reduce inflammation and apoptosis.
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Affiliation(s)
- Youde Jiang
- Department of Ophthalmology, Hamilton Eye Institute, 930 Madison Avenue, Memphis, TN 38163, USA
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91
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Kochanek PM, Dixon CE, Shellington DK, Shin SS, Bayır H, Jackson EK, Kagan VE, Yan HQ, Swauger PV, Parks SA, Ritzel DV, Bauman R, Clark RSB, Garman RH, Bandak F, Ling G, Jenkins LW. Screening of biochemical and molecular mechanisms of secondary injury and repair in the brain after experimental blast-induced traumatic brain injury in rats. J Neurotrauma 2013; 30:920-37. [PMID: 23496248 DOI: 10.1089/neu.2013.2862] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract Explosive blast-induced traumatic brain injury (TBI) is the signature insult in modern combat casualty care and has been linked to post-traumatic stress disorder, memory loss, and chronic traumatic encephalopathy. In this article we report on blast-induced mild TBI (mTBI) characterized by fiber-tract degeneration and axonal injury revealed by cupric silver staining in adult male rats after head-only exposure to 35 psi in a helium-driven shock tube with head restraint. We now explore pathways of secondary injury and repair using biochemical/molecular strategies. Injury produced ∼25% mortality from apnea. Shams received identical anesthesia exposure. Rats were sacrificed at 2 or 24 h, and brain was sampled in the hippocampus and prefrontal cortex. Hippocampal samples were used to assess gene array (RatRef-12 Expression BeadChip; Illumina, Inc., San Diego, CA) and oxidative stress (OS; ascorbate, glutathione, low-molecular-weight thiols [LMWT], protein thiols, and 4-hydroxynonenal [HNE]). Cortical samples were used to assess neuroinflammation (cytokines, chemokines, and growth factors; Luminex Corporation, Austin, TX) and purines (adenosine triphosphate [ATP], adenosine diphosphate, adenosine, inosine, 2'-AMP [adenosine monophosphate], and 5'-AMP). Gene array revealed marked increases in astrocyte and neuroinflammatory markers at 24 h (glial fibrillary acidic protein, vimentin, and complement component 1) with expression patterns bioinformatically consistent with those noted in Alzheimer's disease and long-term potentiation. Ascorbate, LMWT, and protein thiols were reduced at 2 and 24 h; by 24 h, HNE was increased. At 2 h, multiple cytokines and chemokines (interleukin [IL]-1α, IL-6, IL-10, and macrophage inflammatory protein 1 alpha [MIP-1α]) were increased; by 24 h, only MIP-1α remained elevated. ATP was not depleted, and adenosine correlated with 2'-cyclic AMP (cAMP), and not 5'-cAMP. Our data reveal (1) gene-array alterations similar to disorders of memory processing and a marked astrocyte response, (2) OS, (3) neuroinflammation with a sustained chemokine response, and (4) adenosine production despite lack of energy failure-possibly resulting from metabolism of 2'-3'-cAMP. A robust biochemical/molecular response occurs after blast-induced mTBI, with the body protected from blast and the head constrained to limit motion.
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Affiliation(s)
- Patrick M Kochanek
- Department of Critical Care Medicine, Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, USA.
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92
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Gupta RK, Przekwas A. Mathematical Models of Blast-Induced TBI: Current Status, Challenges, and Prospects. Front Neurol 2013; 4:59. [PMID: 23755039 PMCID: PMC3667273 DOI: 10.3389/fneur.2013.00059] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Accepted: 05/09/2013] [Indexed: 01/13/2023] Open
Abstract
Blast-induced traumatic brain injury (TBI) has become a signature wound of recent military activities and is the leading cause of death and long-term disability among U.S. soldiers. The current limited understanding of brain injury mechanisms impedes the development of protection, diagnostic, and treatment strategies. We believe mathematical models of blast wave brain injury biomechanics and neurobiology, complemented with in vitro and in vivo experimental studies, will enable a better understanding of injury mechanisms and accelerate the development of both protective and treatment strategies. The goal of this paper is to review the current state of the art in mathematical and computational modeling of blast-induced TBI, identify research gaps, and recommend future developments. A brief overview of blast wave physics, injury biomechanics, and the neurobiology of brain injury is used as a foundation for a more detailed discussion of multiscale mathematical models of primary biomechanics and secondary injury and repair mechanisms. The paper also presents a discussion of model development strategies, experimental approaches to generate benchmark data for model validation, and potential applications of the model for prevention and protection against blast wave TBI.
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Affiliation(s)
- Raj K Gupta
- Department of Defense Blast Injury Research Program Coordinating Office, U.S. Army Medical Research and Materiel Command , Fort Detrick, MD , USA
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93
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Ahmed F, Gyorgy A, Kamnaksh A, Ling G, Tong L, Parks S, Agoston D. Time-dependent changes of protein biomarker levels in the cerebrospinal fluid after blast traumatic brain injury. Electrophoresis 2013; 33:3705-11. [PMID: 23161535 DOI: 10.1002/elps.201200299] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Revised: 08/30/2012] [Accepted: 09/10/2012] [Indexed: 01/01/2023]
Abstract
Time-dependent changes of protein biomarkers in the cerebrospinal fluid (CSF) can be used to identify the pathological processes in traumatic brain injury (TBI) as well as to follow the progression of the disease. We obtained CSF from a large animal model (swine) of blast-induced traumatic brain injury prior to and at 6, 24, 72 h, and 2 wk after a single exposure to blast overpressure, and determined changes in the CSF levels of neurofilament-heavy chain, neuron-specific enolase, brain-specific creatine kinase, glial fibrillary acidic protein, calcium-binding protein β (S100β), Claudin-5, vascular endothelial growth factor, and von Willebrand factor using reverse phase protein microarray. We detected biphasic temporal patterns in the CSF concentrations of all tested protein markers except S100β. The CSF levels of all markers were significantly increased 6 h after the injury compared to preinjury levels. Values were then decreased at 24 h, prior to a second increase in all markers but S100β at 72 h. At 2 wk postinjury, the CSF concentrations of all biomarkers were decreased once again; brain-specific creatine kinase, Claudin-5, von Willebrand factor, and S100β levels were no longer significantly higher than their preinjury values while neurofilament-heavy chain, neuron-specific enolase, vascular endothelial growth factor, and glial fibrillary acidic protein levels remained significantly elevated compared to baseline. Our findings implicate neuronal and glial cell damage, compromised vascular permeability, and inflammation in blast-induced traumatic brain injury, as well as demonstrate the value of determining the temporal pattern of biomarker changes that may be of diagnostic value.
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Affiliation(s)
- Farid Ahmed
- Department of Anatomy, Physiology and Genetics, Uniformed Services University, Bethesda, MD 20814, USA
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94
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Tümer N, Svetlov S, Whidden M, Kirichenko N, Prima V, Erdos B, Sherman A, Kobeissy F, Yezierski R, Scarpace PJ, Vierck C, Wang KKW. Overpressure blast-wave induced brain injury elevates oxidative stress in the hypothalamus and catecholamine biosynthesis in the rat adrenal medulla. Neurosci Lett 2013; 544:62-7. [PMID: 23570732 DOI: 10.1016/j.neulet.2013.03.042] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 03/13/2013] [Accepted: 03/18/2013] [Indexed: 11/28/2022]
Abstract
Explosive overpressure brain injury (OBI) impacts the lives of both military and civilian population. We hypothesize that a single exposure to OBI results in increased hypothalamic expression of oxidative stress and activation of the sympatho-adrenal medullary axis. Since a key component of blast-induced organ injury is the primary overpressure wave, we assessed selective biochemical markers of autonomic function and oxidative stress in male Sprague Dawley rats subjected to head-directed overpressure insult. Rats were subjected to single head-directed OBI with a 358kPa peak overpressure at the target. Control rats were exposed to just noise signal being placed at ~2m distance from the shock tube nozzle. Sympathetic nervous system activation of the adrenal medullae (AM) was evaluated at 6h following blast injury by assessing the expression of catecholamine biosynthesizing enzymes, tyrosine hydroxylase (TH), dopamine-β hydroxylase (DβH), neuropeptide Y (NPY) along with plasma norepinephrine (NE). TH, DβH and NPY expression increased 20%, 25%, and 91% respectively, following OBI (P<0.05). Plasma NE was also significantly elevated by 23% (P<0.05) following OBI. OBI significantly elevated TH (49%, P<0.05) in the nucleus tractus solitarius (NTS) of the brain stem while AT1 receptor expression and NADPH oxidase activity, a marker of oxidative stress, was elevated in the hypothalamus following OBI. Collectively, the increased levels of TH, DβH and NPY expression in the rat AM, elevated TH in NTS along with increased plasma NE suggest that single OBI exposure results in increased sympathoexcitation. The mechanism may involve the elevated AT1 receptor expression and NADPH oxidase levels in the hypothalamus. Taken together, such effects may be important factors contributing to pathology of brain injury and autonomic dysfunction associated with the clinical profile of patients following OBI.
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Affiliation(s)
- Nihal Tümer
- Geriatric Research, Education and Clinical Center, Department of Veterans Affairs Medical Center, Gainesville, FL 32608, USA.
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95
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Arun P, Abu-Taleb R, Valiyaveettil M, Wang Y, Long JB, Nambiar MP. Extracellular cyclophilin A protects against blast-induced neuronal injury. Neurosci Res 2013; 76:98-100. [PMID: 23511555 DOI: 10.1016/j.neures.2013.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/21/2013] [Accepted: 02/27/2013] [Indexed: 11/17/2022]
Abstract
Blast-induced traumatic brain injury (TBI) and subsequent neurobehavioral deficits are major disabilities suffered by the military and civilian population worldwide. Rigorous scientific research is underway to understand the mechanism of blast TBI and thereby develop effective therapies for protection and treatment. By using an in vitro shock tube model of blast TBI with SH-SY5Y human neuroblastoma cells, we have demonstrated that blast exposure leads to neurobiological changes in an overpressure and time dependent manner. Paradoxically, repeated blast exposures resulted in less neuronal injury compared to single blast exposure and suggested a potential neuroprotective mechanism involving released cyclophilin A (CPA). In the present study, we demonstrate accumulation of CPA in the culture medium after repeated blast exposures supporting the notion of extracellular CPA mediated neuroprotection. Post-exposure treatment of the cells with purified recombinant CPA caused significant protection against blast-induced neuronal injury. Furthermore, repeated blast exposure was associated with phosphorylation of the proteins ERK1/2 and Bad suggesting a potential mechanism of neuroprotection by extracellular CPA and may aid in the development of targeted therapies for protection against blast-induced TBI.
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Affiliation(s)
- Peethambaran Arun
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD 20910, USA.
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96
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Peskind ER, Brody D, Cernak I, McKee A, Ruff RL. Military- and sports-related mild traumatic brain injury: clinical presentation, management, and long-term consequences. J Clin Psychiatry 2013; 74:180-8; quiz 188. [PMID: 23473351 PMCID: PMC5904388 DOI: 10.4088/jcp.12011co1c] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
CME Background Articles are selected for credit designation based on an assessment of the educational needs of CME participants, with the purpose of providing readers with a curriculum of CME articles on a variety of topics throughout each volume. Activities are planned using a process that links identified needs with desired results. Participants may receive credit by reading the article, correctly answering at least 70% of the questions in the Posttest, and completing the Evaluation. The Posttest and Evaluation are now available online only at PSYCHIATRIST.COM (Keyword: February). CME Objective After studying the Commentary by Peskind et al, you should be able to: Accreditation Statement The CME Institute of Physicians Postgraduate Press, Inc., is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. Credit Designation The CME Institute of Physicians Postgraduate Press, Inc., designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 Credit ™. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Note The American Academy of Physician Assistants (AAPA) accepts certificates of participation for educational activities certified for AMA PRA Category 1 Credit ™ from organizations accredited by ACCME or a recognized state medical society. Physician assistants may receive a maximum of 1 hour of Category I credit for completing this program. Date of Original Release/Review This educational activity is eligible for AMA PRA Category 1 Credit ™ through February 29, 2016. The latest review of this material was January 2013.
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Affiliation(s)
- Elaine R Peskind
- Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
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97
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Valiyaveettil M, Alamneh Y, Wang Y, Arun P, Oguntayo S, Wei Y, Long JB, Nambiar MP. Contribution of systemic factors in the pathophysiology of repeated blast-induced neurotrauma. Neurosci Lett 2013; 539:1-6. [PMID: 23370286 DOI: 10.1016/j.neulet.2013.01.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Revised: 01/05/2013] [Accepted: 01/16/2013] [Indexed: 10/27/2022]
Abstract
Blast-induced traumatic brain injury is complex and involves multiple factors including systemic pathophysiological factors in addition to direct brain injuries. We hypothesize that systemic activation of platelets/leukocytes plays a major role in the development and exacerbation of brain injury after blast exposure. A mouse model of repeated blast exposure that results in significant neuropathology, neurobehavioral changes and regional specific alterations in various biomolecules in the brain was used for the proposed study. Activation of platelets was evaluated by flow cytometry and serotonin content was analyzed by ELISA. Expression of myeloperoxidase was analyzed by Western blotting. Histopathology of the brain was used to assess blast-induced cerebral vasoconstriction. The data showed an increase in the activation of platelets at 4h after repeated blast exposures, indicating changes in platelet phenotype in blast neurotrauma. Platelet serotonin concentration showed a significant decrease at 4h after blast with a concurrent increase in the plasma serotonin levels, confirming the early onset of platelet activation after repeated blast exposures. Blood, plasma and brain myeloperoxidase enzyme activity and expression was increased in repeated blast exposed mice at multiple time points. Histopathological analysis of the brains of blast exposed mice showed constriction of blood vessels compared to the respective controls, a phenomenon similar to the reported cerebral vasoconstriction in blast affected victims. These results suggest that repeated blast exposure leads to acute activation of platelets/leukocytes which can augment the pathological effects of brain injury. Platelet/leukocyte targeted therapies can be evaluated as potential acute treatment strategies to mitigate blast-induced neurotrauma.
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Affiliation(s)
- Manojkumar Valiyaveettil
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
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De Gasperi R, Gama Sosa MA, Kim SH, Steele JW, Shaughness MC, Maudlin-Jeronimo E, Hall AA, Dekosky ST, McCarron RM, Nambiar MP, Gandy S, Ahlers ST, Elder GA. Acute blast injury reduces brain abeta in two rodent species. Front Neurol 2012; 3:177. [PMID: 23267342 PMCID: PMC3527696 DOI: 10.3389/fneur.2012.00177] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 12/02/2012] [Indexed: 12/02/2022] Open
Abstract
Blast-induced traumatic brain injury (TBI) has been a major cause of morbidity and mortality in the conflicts in Iraq and Afghanistan. How the primary blast wave affects the brain is not well understood. In particular, it is unclear whether blast injures the brain through mechanisms similar to those found in non-blast closed impact injuries (nbTBI). The β-amyloid (Aβ) peptide associated with the development of Alzheimer’s disease is elevated acutely following TBI in humans as well as in experimental animal models of nbTBI. We examined levels of brain Aβ following experimental blast injury using enzyme-linked immunosorbent assays for Aβ 40 and 42. In both rat and mouse models of blast injury, rather than being increased, endogenous rodent brain Aβ levels were decreased acutely following injury. Levels of the amyloid precursor protein (APP) were increased following blast exposure although there was no evidence of axonal pathology based on APP immunohistochemical staining. Unlike the findings in nbTBI animal models, levels of the β-secretase, β-site APP cleaving enzyme 1, and the γ-secretase component presenilin-1 were unchanged following blast exposure. These studies have implications for understanding the nature of blast injury to the brain. They also suggest that strategies aimed at lowering Aβ production may not be effective for treating acute blast injury to the brain.
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Affiliation(s)
- Rita De Gasperi
- Research and Development Service, James J. Peters Department of Veterans Affairs Medical Center Bronx, NY, USA ; Department of Psychiatry, Mount Sinai School of Medicine New York, NY, USA ; Friedman Brain Institute, Mount Sinai School of Medicine New York, NY, USA
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99
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Valiyaveettil M, Alamneh YA, Miller SA, Hammamieh R, Arun P, Wang Y, Wei Y, Oguntayo S, Long JB, Nambiar MP. Modulation of cholinergic pathways and inflammatory mediators in blast-induced traumatic brain injury. Chem Biol Interact 2012; 203:371-5. [PMID: 23159883 DOI: 10.1016/j.cbi.2012.10.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 10/10/2012] [Accepted: 10/23/2012] [Indexed: 01/12/2023]
Abstract
Cholinergic activity has been recognized as a major regulatory component of stress responses after traumatic brain injury (TBI). Centrally acting acetylcholinesterase (AChE) inhibitors are also being considered as potential therapeutic candidates against TBI mediated cognitive impairments. We have evaluated the expression of molecules involved in cholinergic and inflammatory pathways in various regions of brain after repeated blast exposures in mice. Isoflurane anesthetized C57BL/6J mice were restrained and placed in a prone position transverse to the direction of the shockwaves and exposed to three 20.6 psi blast overpressures with 1-30 min intervals. Brains were collected at the 6h time point after the last blast exposure and subjected to cDNA microarray and microRNA analysis. cDNA microarray analysis showed significant changes in the expression of cholinergic (muscarinic and nicotinic) and gammaaminobutyric acid and glutamate receptors in the midbrain region along with significant changes in multiple genes involved in inflammatory pathways in various regions of the brain. MicroRNA analysis of cerebellum revealed differential expression of miR-132 and 183, which are linked to cholinergic anti-inflammatory signaling, after blast exposure. Changes in the expression of myeloperoxidase in the cerebellum were confirmed by Western blotting. These results indicate that early pathologic progression of blast TBI involves dysregulation of cholinergic and inflammatory pathways related genes. Acute changes in molecules involved in the modulation of cholinergic and inflammatory pathways after blast TBI can cause long-term central and peripheral pathophysiological changes.
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Affiliation(s)
- Manojkumar Valiyaveettil
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
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Theeler BJ, Erickson JC. Posttraumatic headache in military personnel and veterans of the iraq and afghanistan conflicts. Curr Treat Options Neurol 2012; 14:36-49. [PMID: 22116663 DOI: 10.1007/s11940-011-0157-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
OPINION STATEMENT Headaches, particularly migraine, are common in US servicemembers (SMs) who are deployed to or have returned from theaters of combat operations in Iraq and Afghanistan. Concussions and exposure to explosive blasts may be a significant contributor to the increased prevalence of headaches in military veterans. Concussions, usually due to blast exposure, occur in approximately 20% of deployed SMs, and headaches are a common symptom after a deployment-related concussion. Posttraumatic headaches (PTHAs) in US SMs usually resemble migraines, and posttraumatic stress disorder (PTSD) and depression are common comorbidities. Treatment of PTHAs in SMs is based upon the treatment setting, whether the headaches are acute or chronic, the headache phenotype, and associated comorbidities. No randomized, controlled clinical trials evaluating the efficacy of therapies for PTHAs have been completed. Pharmacologic and nonpharmacologic management strategies should be selected on an individual basis. Acute therapy with NSAIDs or triptans and prophylactic therapy in acute and chronic settings using valproate, nortriptyline, amitriptyline, propranolol, topiramate, or botulinum toxin are discussed. Triptans and topiramate may be particularly effective in SMs with PTHA. Management of PTHA and other features of the posttraumatic syndrome should be multidisciplinary whenever possible.
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Affiliation(s)
- Brett J Theeler
- Medical Corps, United States Army, Fort Sam Houston, TX, USA,
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