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Kawauchi S, Kono A, Muramatsu Y, Hennes G, Seki S, Tominaga S, Haruyama Y, Komuta Y, Nishidate I, Matsukuma S, Wang Y, Sato S. Meningeal damage and interface astroglial scarring in the rat brain exposed to a laser-induced shock wave(s). J Neurotrauma 2024. [PMID: 38534205 DOI: 10.1089/neu.2023.0572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024] Open
Abstract
In the past decade, signature clinical neuropathology of blast-induced traumatic brain injury has been under intense debate, but interface astroglial scarring (IAS) seems to be convincing. In this study, we examined whether IAS could be replicated in the rat brain exposed to a laser-induced shock wave(s) (LISW[s]), a tool that can produce a pure shock wave (primary mechanism) without dynamic pressure (tertiary mechanism). Under certain conditions, we observed astroglial scarring in the subpial glial plate (SGP), grey-white matter junctions (GM-WM), ventricular wall (VW) and regions surrounding cortical blood vessels, accurately reproducing clinical IAS. We also observed shock wave impulse-dependent meningeal damage (dural microhemorrhage) in vivo by transcranial near-infrared reflectance imaging. Importantly, there were significant correlations between the degree of dural microhemorrhage and the extent of astroglial scarring more than 7 days post-exposure, suggesting an association of meningeal damage with astroglial scarring. The results demonstrated that the primary mechanism alone caused the IAS and meningeal damage, both of which are attributable to acoustic impedance mismatching at multilayered tissue boundaries. The time course of glial fibrillary acidic protein (GFAP) immunoreactivity depended not only on the LISW conditions but also on the regions. In the SGP, significant increases in GFAP immunoreactivity were observed at 3 days post-exposure, while in the GM-WM and VW, GFAP immunoreactivity was not significantly increased before 14 days post-exposure, suggesting different pathological mechanisms. With the high-impulse single exposure or the multiple exposure (low impulse), fibrotic reaction or fibrotic scar formation was observed, in addition to astroglial scarring, in the cortical surface region. Although there are some limitations, this seems to be the first report on the shock wave-induced IAS rodent model. The model may be useful to explore potential therapeutic approaches for IAS.
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Affiliation(s)
- Satoko Kawauchi
- National Defense Medical College, 13077, Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, 3-2 Namiki, Tokorozawa, Tokorozawa, Saitama, Japan, 359-8513;
| | - Akemi Kono
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, Tokorozawa, Saitama, Japan;
| | - Yuriko Muramatsu
- Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, Tokorozawa, Saitama, Japan;
| | - Grant Hennes
- DRDC Suffield Research Centre, Medicine Hat, Alberta, Canada;
| | - Shuta Seki
- Japan Self Defense Force Central Hospital, Medical Material Department, Setagaya, Tokyo, Japan;
| | - Susumu Tominaga
- National Defense Medical College, 13077, Department of Pathology and Laboratory Medicine, Tokorozawa, Saitama, Japan;
| | - Yasue Haruyama
- National Defense Medical College, 13077, Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, Tokorozawa, Saitama, Japan;
| | - Yukari Komuta
- National Defense Medical College, 13077, Division of Bioinformation and Therapeutic Systems, National Defense Medical College Research Institute, Tokorozawa, Saitama, Japan;
| | - Izumi Nishidate
- Tokyo University of Agriculture and Technology, Graduate School of Bio-Applications & Systems Engineering, 2-24-16, Naka-cho,, Koganei-shi,, Tokyo, Japan, 184-8588;
| | - Susumu Matsukuma
- National Defense Medical College, 13077, Department of Pathology and Laboratory Medicine, Tokorozawa, Saitama, Japan;
| | - Yushan Wang
- DRDC Suffield Research Centre, P.O. Box 4000, Medicine Hat, Alberta, Canada, T1A8K6;
| | - Shunichi Sato
- National Defense Medical College, 13077, Division of Bioinformation and Therapeutic Systems, Research Institute, 3-2, Namiki, Tokorozawa, Saitama, Japan, 359-8513;
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Sachdeva T, Ganpule SG. Twenty Years of Blast-Induced Neurotrauma: Current State of Knowledge. Neurotrauma Rep 2024; 5:243-253. [PMID: 38515548 PMCID: PMC10956535 DOI: 10.1089/neur.2024.0001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024] Open
Abstract
Blast-induced neurotrauma (BINT) is an important injury paradigm of neurotrauma research. This short communication summarizes the current knowledge of BINT. We divide the BINT research into several broad categories-blast wave generation in laboratory, biomechanics, pathology, behavioral outcomes, repetitive blast in animal models, and clinical and neuroimaging investigations in humans. Publications from 2000 to 2023 in each subdomain were considered. The analysis of the literature has brought out salient aspects. Primary blast waves can be simulated reasonably in a laboratory using carefully designed shock tubes. Various biomechanics-based theories of BINT have been proposed; each of these theories may contribute to BINT by generating a unique biomechanical signature. The injury thresholds for BINT are in the nascent stages. Thresholds for rodents are reasonably established, but such thresholds (guided by primary blast data) are unavailable in humans. Single blast exposure animal studies suggest dose-dependent neuronal pathologies predominantly initiated by blood-brain barrier permeability and oxidative stress. The pathologies were typically reversible, with dose-dependent recovery times. Behavioral changes in animals include anxiety, auditory and recognition memory deficits, and fear conditioning. The repetitive blast exposure manifests similar pathologies in animals, however, at lower blast overpressures. White matter irregularities and cortical volume and thickness alterations have been observed in neuroimaging investigations of military personnel exposed to blast. Behavioral changes in human cohorts include sleep disorders, poor motor skills, cognitive dysfunction, depression, and anxiety. Overall, this article provides a concise synopsis of current understanding, consensus, controversies, and potential future directions.
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Affiliation(s)
- Tarun Sachdeva
- Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, India
| | - Shailesh G. Ganpule
- Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, India
- Department of Design, Indian Institute of Technology Roorkee, Roorkee, India
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Sajja V, Shoge R, McNeil E, Van Albert S, Wilder D, Long J. Comparison of Biomechanical Outcome Measures From Characteristically Different Blast Simulators and the Influence of Exposure Location. Mil Med 2023; 188:288-294. [PMID: 37948259 DOI: 10.1093/milmed/usad111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/06/2023] [Accepted: 05/23/2023] [Indexed: 11/12/2023] Open
Abstract
INTRODUCTION Simulation of blast exposure in the laboratory has been inconsistent across laboratories. This is primarily because of adoption of the shock wave-generation techniques that are used in aerodynamic tests as opposed to application of blast exposures that are relevant to combat and training environments of a Warfighter. Because of the differences in blast signatures, characteristically different pathological consequences are observed among the preclinical studies. This is also further confounded by the varied exposure positioning of the animal subject (e.g., inside the blast simulator vs. at the mouth of the simulator). In this study, we compare biomechanical responses to blast exposures created in an advanced blast simulator (ABS) that generates "free-field"-like blast exposure with those produced by a traditionally applied cylindrical blast simulator (CBS) that generates a characteristically different blast signature. In addition, we have tested soft-armor vest protective responses with the ABS and CBS to compare the biomechanical responses to this form of personal protective equipment in each setting in a rodent model. MATERIALS AND METHODS Anesthetized male Sprague-Dawley rats (n = 6) were surgically probed with an intrathoracic pressure (ITP) transducer and an intracranial pressure (ICP) transducer directed into the lateral cerebral ventricle (Millar, Inc.). An ABS for short-duration blast or a CBS for long-duration blast was used to expose animals to an incident blast overpressure of 14.14 psi (impulse: 30.27 psi*msec) or 16.3 psi (impulse: 71.9 psi*msec) using a custom-made holder (n = 3-4/group). An external pitot probe located near the animal was used to measure the total pressure (tip) and static gauge (side-on) pressure. Data were recorded using a TMX-18 data acquisition system (AstroNova Inc.). MATLAB was used to analyze the recordings to identify the peak amplitudes and rise times of the pressure traces. Peak ICP, peak ITP, and their impulses were normalized by expressing them relative to the associated peak static pressure. RESULTS Normalized impulse (ABS: 1.02 ± 0.03 [vest] vs. 1.02 ± 0.01 [no-vest]; CBS: 1.21 ± 0.07 [vest] vs. 1.01 ± 0.01 [no-vest]) and peak pressure for ICP (ABS: 1.03 ± 0.03 [vest] vs. 0.99 ± 0.04 [no-vest]; CBS: 1.06 ± 0.08 [vest] vs. 1.13 ± 0.06 [no-vest]) remained unaltered when comparisons are made between vest and no-vest groups, and the normalized peak ITP (ABS: 1.50 ± 0.02 [vest] vs. 1.24 ± 0.16 [no-vest]; CBS: 1.71 ± 0.20 [vest] vs. 1.37 ± 0.06 [no-vest]) showed a trend of an increase in the vest group compared to the no-vest group. However, impulses in short-duration ABS (0.94 ± 0.06 [vest] vs. 0.92 ± 0.13 [no-vest]) blast remained unaltered, whereas a significant increase of ITP impulse (1.21 ± 0.07 [vest] vs. 1.17 ± 0.01 [no-vest]) in CBS was observed. CONCLUSIONS The differences in the biomechanical response between ABS and CBS could be potentially attributed to the higher dynamic pressures that are imparted from long-duration CBS blasts, which could lead to chest compression and rapid acceleration/deceleration. In addition, ICP and ITP responses occur independently of each other, with no evidence of thoracic surge.
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Affiliation(s)
| | | | - Elizabeth McNeil
- Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | | | - Donna Wilder
- Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Joseph Long
- Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
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Rios KE, Selig DJ, Pavlovic R, Alamneh Y, Vuong C, Nadeau RJ, Pannone KM, Deluca JP, Long JB, Sajja VS, Tyner S, Antonic V, Getnet D, Bobrov AG. Impact of Blast Overpressure on the Pharmacokinetics of Various Antibiotics in Sprague Dawley Rats. Mil Med 2023; 188:271-279. [PMID: 37948226 DOI: 10.1093/milmed/usad107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/03/2023] [Accepted: 04/07/2023] [Indexed: 11/12/2023] Open
Abstract
INTRODUCTION Combat injuries are complex and multimodal. Most injuries to the extremities occur because of explosive devices such as improvised explosive devices. Blast exposure dramatically increases the risk of infection in combat wounds, and there is limited available information on the best antibiotic treatments for these injuries. We previously demonstrated that mice exposed to blast displayed a delayed clearance of cefazolin from the plasma and liver; further semi-mechanistic modeling determined that cefazolin concentrations in the skin of these mice were reduced. Our objective was to investigate the effects of blast on the pharmacokinetics of antibiotics of different types used for the treatment of combat wounds in the rat model. MATERIALS AND METHODS Male Sprague Dawley rats were exposed to blast overpressure followed by injection of a bolus of animal equivalent doses of an antibiotic (cefazolin, cefepime, ertapenem, or clindamycin) into the tail vein at 1-hour post-blast exposure. Blood was collected at predetermined time points via repeated sampling from the tail vein. Animals were also euthanized at predetermined time points, at which time liver, kidney, skin, and blood via cardiac puncture were collected. Antibiotic concentrations were determined by ultra-performance liquid chromatography-tandem mass spectrometry. RESULTS Blast-exposed rats exhibited a similar rate of clearance compared to non-blasted rats in the blood, liver, kidney, and skin, which is inconsistent with the data regarding cefazolin in blast-exposed mice. CONCLUSIONS Our results in rats do not recapitulate our previous observation of delayed cefazolin clearance in mice following the blast overpressure exposure. Although using rats permitted us to collect multiple blood samples from the same animals, rats may not be a suitable model for measuring the pharmacokinetics of antibiotics following blast. The interpretation of the results may be challenging because of variation in data among rat subjects in the same sample groups.
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Affiliation(s)
- Kariana E Rios
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Daniel J Selig
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Radmila Pavlovic
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Yonas Alamneh
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Chau Vuong
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Robert John Nadeau
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Kristina M Pannone
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Jesse P Deluca
- Experimental Therapeutics Branch, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Joseph B Long
- Blast Induced Neurotrauma Branch, Center for Military Psychiatry and Neurosciences, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Venkatasivasai S Sajja
- Blast Induced Neurotrauma Branch, Center for Military Psychiatry and Neurosciences, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Stuart Tyner
- Military Infectious Diseases Research Program, Frederick, MD 21702, USA
| | - Vlado Antonic
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Derese Getnet
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
| | - Alexander G Bobrov
- Wound Infections Department, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA
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Norris C, Weatherbee J, Murphy S, Marquetti I, Maniakhina L, Boruch A, VandeVord P. A closed-body preclinical model to investigate blast-induced spinal cord injury. Front Mol Neurosci 2023; 16:1199732. [PMID: 37383427 PMCID: PMC10293620 DOI: 10.3389/fnmol.2023.1199732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 05/26/2023] [Indexed: 06/30/2023] Open
Abstract
Blast-induced spinal cord injuries (bSCI) are common and account for 75% of all combat-related spinal trauma. It remains unclear how the rapid change in pressure contributes to pathological outcomes resulting from these complex injuries. Further research is necessary to aid in specialized treatments for those affected. The purpose of this study was to develop a preclinical injury model to investigate the behavior and pathophysiology of blast exposure to the spine, which will bring further insight into outcomes and treatment decisions for complex spinal cord injuries (SCI). An Advanced Blast Simulator was used to study how blast exposure affects the spinal cord in a non-invasive manner. A custom fixture was designed to support the animal in a position that protects the vital organs while exposing the thoracolumbar region of the spine to the blast wave. The Tarlov Scale and Open Field Test (OFT) were used to detect changes in locomotion or anxiety, respectively, 72 h following bSCI. Spinal cords were then harvested and histological staining was performed to investigate markers of traumatic axonal injury (β-APP, NF-L) and neuroinflammation (GFAP, Iba1, S100β). Analysis of the blast dynamics demonstrated that this closed-body model for bSCI was found to be highly repeatable, administering consistent pressure pulses following a Friedlander waveform. There were no significant changes in acute behavior; however, expression of β-APP, Iba1, and GFAP significantly increased in the spinal cord following blast exposure (p < 0.05). Additional measures of cell count and area of positive signal provided evidence of increased inflammation and gliosis in the spinal cord at 72 h after blast injury. These findings indicated that pathophysiological responses from the blast alone are detectable, likely contributing to the combined effects. This novel injury model also demonstrated applications as a closed-body SCI model for neuroinflammation enhancing relevance of the preclinical model. Further investigation is necessary to assess the longitudinal pathological outcomes, combined effects from complex injuries, and minimally invasive treatment approaches.
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Affiliation(s)
- Carly Norris
- School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA, United States
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, United States
| | - Justin Weatherbee
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, United States
| | - Susan Murphy
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, United States
- Veterans Affairs Medical Center, Salem, VA, United States
| | - Izabele Marquetti
- Edward Via College of Osteopathic Medicine, Carolinas Campus, Spartanburg, SC, United States
| | - Lana Maniakhina
- Edward Via College of Osteopathic Medicine, Carolinas Campus, Spartanburg, SC, United States
| | - Alan Boruch
- Edward Via College of Osteopathic Medicine, Carolinas Campus, Spartanburg, SC, United States
| | - Pamela VandeVord
- School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA, United States
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, United States
- Veterans Affairs Medical Center, Salem, VA, United States
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Wiri S, Massow T, Reid J, Whitty J, Dunbar C, Graves W, Gonzales A, Ortley D, Longwell J, Needham CE, Ziegle A, Phan V, Leonessa F, Duckworth JL. Dynamic monitoring of service members to quantify blast exposure levels during combat training using BlackBox Biometrics Blast Gauges: explosive breaching, shoulder-fired weapons, artillery, mortars, and 0.50 caliber guns. Front Neurol 2023; 14:1175671. [PMID: 37305738 PMCID: PMC10248048 DOI: 10.3389/fneur.2023.1175671] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/02/2023] [Indexed: 06/13/2023] Open
Abstract
CONQUER is a pilot blast monitoring program that monitors, quantifies, and reports to military units the training-related blast overpressure exposure of their service members. Overpressure exposure data are collected using the BlackBox Biometrics (B3) Blast Gauge System (BGS, generation 7) sensors mounted on the body during training. To date, the CONQUER program has recorded 450,000 gauge triggers on monitored service members. The subset of data presented here has been collected from 202 service members undergoing training with explosive breaching charges, shoulder-fired weapons, artillery, mortars, and 0.50 caliber guns. Over 12,000 waveforms were recorded by the sensors worn by these subjects. A maximum peak overpressure of 90.3 kPa (13.1 psi) was recorded during shoulder-fired weapon training. The largest overpressure impulse (a measure of blast energy) was 82.0 kPa-ms (11.9 psi-ms) and it was recorded during explosive breaching with a large wall charge. Operators of 0.50 caliber machine guns have the lowest peak overpressure impulse (as low as 0.62 kPa-ms or 0.09 psi-ms) of the blast sources considered. The data provides information on the accumulation of blast overpressure on service members over an extended period of time. The cumulative peak overpressure, peak overpressure impulse, or timing between exposures is all available in the exposure data.
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Affiliation(s)
- Suthee Wiri
- Applied Research Associates, Albuquerque, NM, United States
| | - Todd Massow
- Neurology Department, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - James Reid
- Neurology Department, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Joshua Whitty
- Neurology Department, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Cyrus Dunbar
- Neurology Department, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Wallace Graves
- Neurology Department, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | | | - David Ortley
- Applied Research Associates, Albuquerque, NM, United States
| | | | | | - Alex Ziegle
- Applied Research Associates, Albuquerque, NM, United States
| | - Virginia Phan
- Applied Research Associates, Albuquerque, NM, United States
| | - Fabio Leonessa
- Neurology Department, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Josh L Duckworth
- Neurology Department, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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Paik CB, Pei M, Oghalai JS. Review of blast noise and the auditory system. Hear Res 2022; 425:108459. [PMID: 35181171 PMCID: PMC9357863 DOI: 10.1016/j.heares.2022.108459] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 11/22/2022]
Abstract
The auditory system is particularly vulnerable to blast injury due to the ear's role as a highly sensitive pressure transducer. Over the past several decades, studies have used a variety of animal models and experimental procedures to recreate blast-induced acoustic trauma. Given the developing nature of this field and our incomplete understanding of molecular mechanisms underlying blast-related auditory disturbances, an updated discussion about these studies is warranted. Here, we comprehensively review well-established blast-related auditory pathology including tympanic membrane perforation and hair cell loss. In addition, we discuss important mechanistic studies that aim to bridge gaps in our current understanding of the molecular and microstructural events underlying blast-induced cochlear, auditory nerve, brainstem, and central auditory system damage. Key findings from the recent literature include the association between endolymphatic hydrops and cochlear synaptic loss, blast-induced neuroinflammatory markers in the peripheral and central auditory system, and therapeutic approaches targeting biochemical markers of blast injury. We conclude that blast is an extreme form of noise exposure. Blast waves produce cochlear damage that appears similar to, but more extreme than, the standard noise exposure protocols used in auditory research. However, experimental variations in studies of blast-induced acoustic trauma make it challenging to compare and interpret data across studies.
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Affiliation(s)
- Connie B Paik
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA
| | - Michelle Pei
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA
| | - John S Oghalai
- Caruso Department of Otolaryngology-Head and Neck Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA USA.
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Establishment of a combat damage control surgery training platform for explosive combined thoraco-abdominal injuries. Chin J Traumatol 2022; 25:193-200. [PMID: 35331606 PMCID: PMC9252934 DOI: 10.1016/j.cjtee.2022.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 12/31/2021] [Accepted: 01/18/2022] [Indexed: 02/04/2023] Open
Abstract
PURPOSE It is challenging to prepare military surgeons with the skills of combat damage control surgery (CDCS). The current study aimed to establish a damage control surgery (DCS) training platform for explosive combined thoraco-abdominal injuries. METHODS The training platform established in this study consisted of 3 main components: (1) A 50 m × 50 m square yard was constructed as the explosion site. Safety was assessed through cameras. (2) Sixteen pigs were injured by an explosion of trinitrotoluene attached with steel balls and were randomly divided into the DCS group (accepted DCS) and the control group (have not accepted DCS). The mortality rate was observed. (3) The literature was reviewed to identify the key factors for assessing CDCS, and testing standards for CDCS were then established. Expert questionnaires were employed to evaluate the scientificity and feasibility of the testing standards. Then, a 5-day training course with incorporated tests was used to test the efficacy of the established platform. In total, 30 teams attended the first training course. The scores that the trainees received before and after the training were compared. SPSS 11.0 was employed to analyze the results. RESULTS The high-speed video playback confirmed the safety of the explosion site as no explosion fragments projected beyond the wall. No pig died within 24 h when DCS was performed, while 7 pigs died in the control group. After a literature review, assessment criteria for CDCS were established that had a total score of 100 points and had 4 major parts: leadership and team cooperation, resuscitation, surgical procedure, and final outcome. Expert questionnaire results showed that the scientific score was 8.6 ± 1.25, and the feasibility score was 8.74 ± 1.19. When compared with the basic level, the trainees' score improved significantly after training. CONCLUSION The platform established in this study was useful for CDCS training.
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McNamara EH, Tucker LB, Liu J, Fu AH, Kim Y, Vu PA, McCabe JT. Limbic Responses Following Shock Wave Exposure in Male and Female Mice. Front Behav Neurosci 2022; 16:863195. [PMID: 35747840 PMCID: PMC9210954 DOI: 10.3389/fnbeh.2022.863195] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/04/2022] [Indexed: 01/26/2023] Open
Abstract
Blast traumatic brain injury (bTBI) presents a serious threat to military personnel and often results in psychiatric conditions related to limbic system dysfunction. In this study, the functional outcomes for anxiety- and depressive-like behaviors and neuronal activation were evaluated in male and female mice after exposure to an Advanced Blast Simulator (ABS) shock wave. Mice were placed in a ventrally exposed orientation inside of the ABS test section and received primary and tertiary shock wave insults of approximately 15 psi peak pressure. Evans blue staining indicated cases of blood-brain barrier breach in the superficial cerebral cortex four, but not 24 h after blast, but the severity was variable. Behavioral testing with the elevated plus maze (EPM) or elevated zero maze (EZM), sucrose preference test (SPT), and tail suspension test (TST) or forced swim test (FST) were conducted 8 days–3.5 weeks after shock wave exposure. There was a sex difference, but no injury effect, for distance travelled in the EZM where female mice travelled significantly farther than males. The SPT and FST did not indicate group differences; however, injured mice were less immobile than sham mice during the TST; possibly indicating more agitated behavior. In a separate cohort of animals, the expression of the immediate early gene, c-Fos, was detected 4 h after undergoing bTBI or sham procedures. No differences in c-Fos expression were found in the cerebral cortex, but female mice in general displayed enhanced c-Fos activation in the paraventricular nucleus of the thalamus (PVT) compared to male mice. In the amygdala, more c-Fos-positive cells were observed in injured animals compared to sham mice. The observed sex differences in the PVT and c-Fos activation in the amygdala may correlate with the reported hyperactivity of females post-injury. This study demonstrates, albeit with mild effects, behavioral and neuronal activation correlates in female rodents after blast injury that could be relevant to the incidence of increased post-traumatic stress disorder in women.
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Affiliation(s)
- Eileen H. McNamara
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Laura B. Tucker
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, Bethesda, MD, United States
| | - Jiong Liu
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Amanda H. Fu
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, Bethesda, MD, United States
| | - Yeonho Kim
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, Bethesda, MD, United States
| | - Patricia A. Vu
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Joseph T. McCabe
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, Bethesda, MD, United States
- *Correspondence: Joseph T. McCabe,
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10
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Bishop R, Won SJ, Irvine KA, Basu J, Rome ES, Swanson RA. Blast-induced axonal degeneration in the rat cerebellum in the absence of head movement. Sci Rep 2022; 12:143. [PMID: 34996954 PMCID: PMC8741772 DOI: 10.1038/s41598-021-03744-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 12/02/2021] [Indexed: 11/16/2022] Open
Abstract
Blast exposure can injure brain by multiple mechanisms, and injury attributable to direct effects of the blast wave itself have been difficult to distinguish from that caused by rapid head displacement and other secondary processes. To resolve this issue, we used a rat model of blast exposure in which head movement was either strictly prevented or permitted in the lateral plane. Blast was found to produce axonal injury even with strict prevention of head movement. This axonal injury was restricted to the cerebellum, with the exception of injury in visual tracts secondary to ocular trauma. The cerebellar axonal injury was increased in rats in which blast-induced head movement was permitted, but the pattern of injury was unchanged. These findings support the contentions that blast per se, independent of head movement, is sufficient to induce axonal injury, and that axons in cerebellar white matter are particularly vulnerable to direct blast-induced injury.
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Affiliation(s)
- Robin Bishop
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
| | - Seok Joon Won
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA.
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA.
| | - Karen-Amanda Irvine
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
- Anesthesiology Service, Veterans Affairs Palo Alto Health Care System, 3801 Miranda Ave (E4-220), Palo Alto, CA, 94304, USA
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University, School of Medicine, Stanford, CA, 94305, USA
| | - Jayinee Basu
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
| | - Eric S Rome
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
| | - Raymond A Swanson
- Department of Neurology, University of California at San Francisco, San Francisco, CA, 94158, USA
- (127)Neurology, San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
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11
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Faillot M, Chaillet A, Palfi S, Senova S. Rodent models used in preclinical studies of deep brain stimulation to rescue memory deficits. Neurosci Biobehav Rev 2021; 130:410-432. [PMID: 34437937 DOI: 10.1016/j.neubiorev.2021.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 08/10/2021] [Accepted: 08/13/2021] [Indexed: 11/28/2022]
Abstract
Deep brain stimulation paradigms might be used to treat memory disorders in patients with stroke or traumatic brain injury. However, proof of concept studies in animal models are needed before clinical translation. We propose here a comprehensive review of rodent models for Traumatic Brain Injury and Stroke. We systematically review the histological, behavioral and electrophysiological features of each model and identify those that are the most relevant for translational research.
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Affiliation(s)
- Matthieu Faillot
- Neurosurgery department, Henri Mondor University Hospital, APHP, DMU CARE, Université Paris Est Créteil, Mondor Institute for Biomedical Research, INSERM U955, Team 15, Translational Neuropsychiatry, France
| | - Antoine Chaillet
- Laboratoire des Signaux et Systèmes (L2S-UMR8506) - CentraleSupélec, Université Paris Saclay, Institut Universitaire de France, France
| | - Stéphane Palfi
- Neurosurgery department, Henri Mondor University Hospital, APHP, DMU CARE, Université Paris Est Créteil, Mondor Institute for Biomedical Research, INSERM U955, Team 15, Translational Neuropsychiatry, France
| | - Suhan Senova
- Neurosurgery department, Henri Mondor University Hospital, APHP, DMU CARE, Université Paris Est Créteil, Mondor Institute for Biomedical Research, INSERM U955, Team 15, Translational Neuropsychiatry, France.
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12
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Dependence of visual and cognitive outcomes on animal holder configuration in a rodent model of blast overpressure exposure. Vision Res 2021; 188:162-173. [PMID: 34333201 DOI: 10.1016/j.visres.2021.07.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 05/24/2021] [Accepted: 07/14/2021] [Indexed: 02/04/2023]
Abstract
Blast-induced traumatic brain injury is the signature injury of modern military conflicts. To more fully understand the effects of blast exposure, we placed rats in different holder configurations, exposed them to blast overpressure, and assessed the degree of eye and brain injury. Anesthetized Long-Evans rats received blast exposures directed at the head (63 kPa, 195 dB-SPL) in either an "open holder" (head and neck exposed; n = 7), or an "enclosed holder" (window for blast exposure to eye; n = 15) and were compared to non-blast exposed (control) rats (n = 22). Outcomes included optomotor response (OMR), electroretinography (ERG), and spectral domain optical coherence tomography (SD-OCT) at 2, 4, and 6 months post-blast, and cognitive function (Y-maze) at 3 months. Spatial frequency and contrast sensitivity were reduced in ipsilateral blast-exposed eyes in both holders (p < 0.01), while contralateral eyes showed greater deficits with the enclosed holder (p < 0.05). Thinner retinas (p < 0.001) and reduced ERG a- and b- wave amplitudes (p < 0.05) were observed for both ipsilateral and contralateral eyes with the enclosed, but not the open, holder. Rats in the open holder showed cognitive deficits compared to rats in the enclosed holder (p < 0.05). Overall, the animal holder configuration used in blast exposure studies can significantly affect outcomes. Enclosed holders may cause secondary damage to the contralateral eye by concussive injury or blast wave reflection off the holder wall. Open holders may damage the brain via rapid head movement (contrecoup injury). These results highlight additional factors to be considered when evaluating patients with blast exposure or developing models of blast injury.
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13
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Denny JW, Dickinson AS, Langdon GS. Defining blast loading 'zones of relevance' for primary blast injury research: A consensus of injury criteria for idealised explosive scenarios. Med Eng Phys 2021; 93:83-92. [PMID: 34154779 DOI: 10.1016/j.medengphy.2021.05.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 03/23/2021] [Accepted: 05/21/2021] [Indexed: 11/18/2022]
Abstract
Blast injuries remain a serious threat to defence and civilian populations around the world. 'Primary' blast injuries (PBIs) are caused by direct blast wave interaction with the human body, particularly affecting air-containing organs. Work to define blast loading conditions for injury research has received relatively little attention, though with a continued experimental focus on PBIs and idealised explosion assumptions, meaningful test outcomes and subsequent clinical applications, rely on appropriate simulated conditions. This paper critically evaluates and combines existing PBI criteria (grouped into those affecting the auditory system, pulmonary injuries and brain trauma) as a function of idealised blast wave parameters. For clinical blast injury researchers, analysis of the multi-injury criteria indicates zones of appropriate loading conditions for human-scale test items and demonstrates the importance of simulating blast conditions that are both realistic and relevant to the injury type. For certain explosive scenarios, spatial interpretation of the 'zones of relevance' could support emergency response and hazard preparedness by informing triage, patient management and resource allocation, thus leading to improved health outcomes. This work will prove useful to clinical blast injury researchers, blast protection engineers and clinical practitioners involved in the triage, diagnosis, and treatment of PBIs.
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Affiliation(s)
- J W Denny
- Department of Mechanical Engineering, University of Southampton, Southampton, SO17 1BJ, UK.
| | - A S Dickinson
- Department of Mechanical Engineering, University of Southampton, Southampton, SO17 1BJ, UK
| | - G S Langdon
- Department of Civil and Structural Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK; Department of Mechanical Engineering, University of Cape Town, Cape Town, South Africa
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14
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Rutter B, Song H, DePalma RG, Hubler G, Cui J, Gu Z, Johnson CE. Shock Wave Physics as Related to Primary Non-Impact Blast-Induced Traumatic Brain Injury. Mil Med 2021; 186:601-609. [PMID: 33499439 DOI: 10.1093/milmed/usaa290] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/24/2020] [Accepted: 08/21/2020] [Indexed: 11/12/2022] Open
Abstract
INTRODUCTION Blast overpressure exposure, an important cause of traumatic brain injury (TBI), may occur during combat or military training. TBI, most commonly mild TBI, is considered a signature injury of recent combat in Iraq and Afghanistan. Low intensity primary blast-induced TBI (bTBI), caused by exposure to an explosive shock wave, commonly leaves no obvious physical external signs. Numerous studies have been conducted to understand its biological effects; however, the role of shock wave energy as related to bTBI remains poorly understood. This report combines shock wave analysis with established biological effects on the mouse brain to provide insights into the effects of shock wave physics as related to low intensity bTBI outcomes from both open-air and shock tube environments. METHODS Shock wave peak pressure, rise time, positive phase duration, impulse, shock velocity, and particle velocity were measured using the Missouri open-air blast model from 16 blast experiments totaling 122 mice to quantify physical shock wave properties. Open-air shock waves were generated by detonating 350-g 1-m suspended Composition C-4 charges with targets on 1-m elevated stands at 2.15, 3, 4, and 7 m from the source. RESULTS All mice sustained brain injury with no observable head movement, because of mice experiencing lower dynamic pressures than calculated in shock tubes. Impulse, pressure loading over time, was found to be directly related to bTBI severity and is a primary shock physics variable that relates to bTBI. DISCUSSION The physical blast properties including shock wave peak pressure, rise time, positive phase duration, impulse, shock velocity, and particle velocity were examined using the Missouri open-air blast model in mice with associated neurobehavioral deficits. The blast-exposed mice sustained ultrastructural abnormalities in mitochondria, myelinated axons, and synapses, implicating that primary low intensity blast leads to nanoscale brain damage by providing the link to its pathogenesis. The velocity of the shock wave reflected back from the target stand was calculated from high-speed video and compared with that of the incident shock wave velocity. Peak incident pressure measured from high sample rate sensors was found to be within 1% of the velocity recorded by the high-speed camera, concluding that using sensors in or close to an animal brain can provide useful information regarding shock velocity within the brain, leading to more advanced knowledge between shock wave physics and tissue damage that leads to bTBIs.
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Affiliation(s)
- Barbara Rutter
- Department of Mining and Nuclear Engineering, Missouri University of Science and Technology, Rolla, MO 65401, USA
| | - Hailong Song
- Department of Pathology & Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Ralph G DePalma
- Department of Veterans Affairs, Washington, DC, Office of Research and Development, NW 20420, USA.,Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Graham Hubler
- Department of Pathology & Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Jiankun Cui
- Department of Pathology & Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO 65212, USA.,Truman VA Hospital Research Service, Columbia, MO 65201, USA
| | - Zezong Gu
- Department of Pathology & Anatomical Sciences, University of Missouri School of Medicine, Columbia, MO 65212, USA.,Truman VA Hospital Research Service, Columbia, MO 65201, USA
| | - Catherine E Johnson
- Department of Mining and Nuclear Engineering, Missouri University of Science and Technology, Rolla, MO 65401, USA
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15
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Arun P, Rossetti F, Wilder DM, Wang Y, Gist ID, Long JB. Blast Exposure Causes Long-Term Degeneration of Neuronal Cytoskeletal Elements in the Cochlear Nucleus: A Potential Mechanism for Chronic Auditory Dysfunctions. Front Neurol 2021; 12:652190. [PMID: 33841318 PMCID: PMC8027061 DOI: 10.3389/fneur.2021.652190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/15/2021] [Indexed: 11/13/2022] Open
Abstract
Blast-induced auditory dysfunctions including tinnitus are the most prevalent disabilities in service members returning from recent combat operations. Most of the previous studies were focused on the effect of blast exposure on the peripheral auditory system and not much on the central auditory signal-processing regions in the brain. In the current study, we have exposed rats to single and tightly coupled repeated blasts and examined the degeneration of neuronal cytoskeletal elements using silver staining in the central auditory signal-processing regions in the brain at 24 h, 14 days, 1 month, 6 months, and 1 year. The brain regions evaluated include cochlear nucleus, lateral lemniscus, inferior colliculus, medial geniculate nucleus, and auditory cortex. The results obtained indicated that a significant increase in degeneration of neuronal cytoskeletal elements was observed only in the left and right cochlear nucleus. A significant increase in degeneration of neuronal cytoskeletal elements was observed in the cochlear nucleus at 24 h and persisted through 1 year, suggesting acute and chronic neuronal degeneration after blast exposure. No statistically significant differences were observed between single and repeated blasts. The localized degeneration of neuronal cytoskeletal elements in the cochlear nucleus suggests that the damage could be caused by transmission of blast shockwaves/noise through the ear canal and that use of suitable ear protection devices can protect against acute and chronic central auditory signal processing defects including tinnitus after blast exposure.
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Affiliation(s)
- Peethambaran Arun
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Franco Rossetti
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Donna M Wilder
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Ying Wang
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Irene D Gist
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Joseph B Long
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States
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16
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Dual-laser measurement of human stapes footplate motion under blast exposure. Hear Res 2021; 403:108177. [PMID: 33524791 DOI: 10.1016/j.heares.2021.108177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 12/24/2020] [Accepted: 01/18/2021] [Indexed: 11/21/2022]
Abstract
Hearing damage is one of the most frequently observed injuries in Service members and Veterans even though hearing protection devices (HPDs, e.g. earplugs) have been implemented to prevent blast-induced hearing loss. However, the formation and prevention mechanism of the blast-induced hearing damage remains unclear due to the difficulty for conducting biomechanical measurements in ears during blast exposure. Recently, an approach reported by Jiang et al. (2019) used two laser Doppler vibrometers (LDVs) to measure the motion of the tympanic membrane (TM) in human temporal bones during blast exposure. Using the dual laser setup, we further developed the technology to detect the movement of the stapes footplate (SFP) in ears with and without HPDs while under blast exposure. Eight fresh human cadaveric temporal bones (TBs) were involved in this study. The TB was mounted in a "head block" after performing a facial recess surgery to access the SFP, and a pressure sensor was inserted near the TM in the ear canal to measure the pressure reaching the TM (P1). The TB was exposed to a blast overpressure measuring around 7 psi or 48 kPa at the entrance of the ear canal (P0). Two LDVs were used to measure the vibrations of the SFP and TB (as a reference). The exact motion of the SFP was determined by subtracting the TB motion from the SFP data. Results included a measured peak-to-peak SFP displacement of 68.7 ± 31.6 μm (mean ± SD) from all eight TBs without HPDs. In five of the TBs, the insertion of a foam earplug reduced the SFP displacement from 48.3 ± 6.3 μm to 21.8 ± 10.4 μm. The time-frequency analysis of the SFP velocity signals indicated that most of the energy spectrum was concentrated at frequencies below 4 kHz within the first 2 ms after blast and the energy was reduced after the insertion of HPDs. This study describes a new methodology to quantitatively characterize the response of the middle ear and the energy entering the cochlea during blast exposure. The experimental data are critical for determining the injury of the peripheral auditory system and elucidating the damage formation and prevention mechanism in an ear exposed to blast.
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17
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Sutar S, Ganpule SG. Assessment of Compression Driven Shock Tube Designs in Replicating Free-Field Blast Conditions for Traumatic Brain Injury Studies. J Neurotrauma 2021; 38:1717-1729. [PMID: 33108952 DOI: 10.1089/neu.2020.7394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Compression driven shock tubes are indispensable in studies of blast-induced traumatic brain injury (bTBI). The ability of shock tubes in faithfully recreating free-field blast conditions is of enormous interest and has a direct impact on injury outcomes. Toward this end, the evolution of blast wave inside and outside of the compression driven shock tube has been studied using validated, finite element based shock tube models. Several shock tube configurations (uniform cross-section, transition, conical, suddenly expanded, and end plate) have been considered. The finite element modeling approach has been used to simulate the transient, dynamic response of blast wave propagation. The response is studied for longer durations (40-100 msec) compared with the existing literature. We demonstrate that locations inside and outside of the shock tube can generate free-field blast profile in some form, but with numerous caveats. Our results indicate that the locations inside the shock tube are affected by higher underpressure and corresponding kinetic energy yield compared with free-field blast. These effects can be minimized using optimized end plate configuration at the exit of the shock tube, yet this is accompanied by secondary loading that is not representative of the free-field blast. Blast wave profile can be tailored using transition, conical, and suddenly expanded sections. We observe oscillations in the blast wave profile for suddenly expanded configuration. Locations outside the shock tube are affected by jet-wind effects because of the sudden expansion, barring a narrow region at the exit. For the desired overpressure yield inferred in bTBI, obtaining positive phase durations of <1 msec inside the shock tube, which are sought for studies in rodents, is challenging. Overall, these results underscore that replicating free-field blast conditions using a shock tube involves tradeoffs that need to be weighed carefully and their effect on injury outcomes should be evaluated during laboratory bTBI investigations.
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Affiliation(s)
- Sunil Sutar
- Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, India
| | - S G Ganpule
- Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee, India
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18
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Shin MK, Vázquez-Rosa E, Cintrón-Pérez CJ, Riegel WA, Harper MM, Ritzel D, Pieper AA. Characterization of the Jet-Flow Overpressure Model of Traumatic Brain Injury in Mice. Neurotrauma Rep 2021; 2:1-13. [PMID: 33748810 PMCID: PMC7962691 DOI: 10.1089/neur.2020.0020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The jet-flow overpressure chamber (OPC) has been previously reported as a model of blast-mediated traumatic brain injury (bTBI). However, rigorous characterization of the features of this injury apparatus shows that it fails to recapitulate exposure to an isolated blast wave. Through combined experimental and computational modeling analysis of gas-dynamic flow conditions, we show here that the jet-flow OPC produces a collimated high-speed jet flow with extreme dynamic pressure that delivers a severe compressive impulse. Variable rupture dynamics of the diaphragm through which the jet flow originates also generate a weak and infrequent shock front. In addition, there is a component of acceleration-deceleration injury to the head as it is agitated in the headrest. Although not a faithful model of free-field blast exposure, the jet-flow OPC produces a complex multi-modal model of TBI that can be useful in laboratory investigation of putative TBI therapies and fundamental neurophysiological processes after brain injury.
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Affiliation(s)
- Min-Kyoo Shin
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA.,Department of Psychiatry and Department of Neuroscience, Case Western Reserve University, Cleveland, Ohio, USA.,Geriatric Research Education and Clinical Centers, Louis Stokes Cleveland VAMC, Cleveland, Ohio, USA
| | - Edwin Vázquez-Rosa
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA.,Department of Psychiatry and Department of Neuroscience, Case Western Reserve University, Cleveland, Ohio, USA.,Geriatric Research Education and Clinical Centers, Louis Stokes Cleveland VAMC, Cleveland, Ohio, USA
| | - Coral J Cintrón-Pérez
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA.,Department of Psychiatry and Department of Neuroscience, Case Western Reserve University, Cleveland, Ohio, USA.,Geriatric Research Education and Clinical Centers, Louis Stokes Cleveland VAMC, Cleveland, Ohio, USA
| | - William A Riegel
- Stumptown Research and Development, LLC, Black Mountain, North Carolina, USA
| | - Matthew M Harper
- Center for the Prevention and Treatment of Visual Loss, Veterans Affairs Medical Center, Iowa City, Iowa, USA.,Departments of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA
| | - David Ritzel
- Dyn-FX Consulting, Ltd., Amherstburg, Ontario, Canada
| | - Andrew A Pieper
- Harrington Discovery Institute, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA.,Department of Psychiatry and Department of Neuroscience, Case Western Reserve University, Cleveland, Ohio, USA.,Geriatric Research Education and Clinical Centers, Louis Stokes Cleveland VAMC, Cleveland, Ohio, USA
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19
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Rubio JE, Skotak M, Alay E, Sundaramurthy A, Subramaniam DR, Kote VB, Yeoh S, Monson K, Chandra N, Unnikrishnan G, Reifman J. Does Blast Exposure to the Torso Cause a Blood Surge to the Brain? Front Bioeng Biotechnol 2020; 8:573647. [PMID: 33392161 PMCID: PMC7773947 DOI: 10.3389/fbioe.2020.573647] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 11/16/2020] [Indexed: 02/04/2023] Open
Abstract
The interaction of explosion-induced blast waves with the torso is suspected to contribute to brain injury. In this indirect mechanism, the wave-torso interaction is assumed to generate a blood surge, which ultimately reaches and damages the brain. However, this hypothesis has not been comprehensively and systematically investigated, and the potential role, if any, of the indirect mechanism in causing brain injury remains unclear. In this interdisciplinary study, we performed experiments and developed mathematical models to address this knowledge gap. First, we conducted blast-wave exposures of Sprague-Dawley rats in a shock tube at incident overpressures of 70 and 130 kPa, where we measured carotid-artery and brain pressures while limiting exposure to the torso. Then, we developed three-dimensional (3-D) fluid-structure interaction (FSI) models of the neck and cerebral vasculature and, using the measured carotid-artery pressures, performed simulations to predict mass flow rates and wall shear stresses in the cerebral vasculature. Finally, we developed a 3-D finite element (FE) model of the brain and used the FSI-computed vasculature pressures to drive the FE model to quantify the blast-exposure effects in the brain tissue. The measurements from the torso-only exposure experiments revealed marginal increases in the peak carotid-artery overpressures (from 13.1 to 28.9 kPa). Yet, relative to the blast-free, normotensive condition, the FSI simulations for the blast exposures predicted increases in the peak mass flow rate of up to 255% at the base of the brain and increases in the wall shear stress of up to 289% on the cerebral vasculature. In contrast, our simulations suggest that the effect of the indirect mechanism on the brain-tissue-strain response is negligible (<1%). In summary, our analyses show that the indirect mechanism causes a sudden and abundant stream of blood to rapidly propagate from the torso through the neck to the cerebral vasculature. This blood surge causes a considerable increase in the wall shear stresses in the brain vasculature network, which may lead to functional and structural effects on the cerebral veins and arteries, ultimately leading to vascular pathology. In contrast, our findings do not support the notion of strain-induced brain-tissue damage due to the indirect mechanism.
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Affiliation(s)
- Jose E Rubio
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States.,The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Maciej Skotak
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials, and Medicine, New Jersey Institute of Technology, Newark, NJ, United States.,Blast Induced Neurotrauma Division, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Eren Alay
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials, and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
| | - Aravind Sundaramurthy
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States.,The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Dhananjay Radhakrishnan Subramaniam
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States.,The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Vivek Bhaskar Kote
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States.,The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Stewart Yeoh
- Department of Biomedical Engineering, College of Engineering, The University of Utah, Salt Lake City, UT, United States
| | - Kenneth Monson
- Department of Biomedical Engineering, College of Engineering, The University of Utah, Salt Lake City, UT, United States.,Department of Mechanical Engineering, College of Engineering, The University of Utah, Salt Lake City, UT, United States
| | - Namas Chandra
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials, and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
| | - Ginu Unnikrishnan
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States.,The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, United States Army Medical Research and Development Command, Fort Detrick, MD, United States
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20
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Arun P, Rossetti F, DeMar JC, Wang Y, Batuure AB, Wilder DM, Gist ID, Morris AJ, Sabbadini RA, Long JB. Antibodies Against Lysophosphatidic Acid Protect Against Blast-Induced Ocular Injuries. Front Neurol 2020; 11:611816. [PMID: 33384658 PMCID: PMC7769950 DOI: 10.3389/fneur.2020.611816] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/24/2020] [Indexed: 01/18/2023] Open
Abstract
Exposure to blast overpressure waves is implicated as the major cause of ocular injuries and resultant visual dysfunction in veterans involved in recent combat operations. No effective therapeutic strategies have been developed so far for blast-induced ocular dysfunction. Lysophosphatidic acid (LPA) is a bioactive phospholipid generated by activated platelets, astrocytes, choroidal plexus cells, and microglia and is reported to play major roles in stimulating inflammatory processes. The levels of LPA in the cerebrospinal fluid have been reported to increase acutely in patients with traumatic brain injury (TBI) as well as in a controlled cortical impact (CCI) TBI model in mice. In the present study, we have evaluated the efficacy of a single intravenous administration of a monoclonal LPA antibody (25 mg/kg) given at 1 h post-blast for protection against injuries to the retina and associated ocular dysfunctions. Our results show that a single 19 psi blast exposure significantly increased the levels of several species of LPA in blood plasma at 1 and 4 h post-blast. The anti-LPA antibody treatment significantly decreased glial cell activation and preserved neuronal cell morphology in the retina on day 8 after blast exposure. Optokinetic measurements indicated that anti-LPA antibody treatment significantly improved visual acuity in both eyes on days 2 and 6 post-blast exposure. Anti-LPA antibody treatment significantly increased rod photoreceptor and bipolar neuronal cell signaling in both eyes on day 7 post-blast exposure. These results suggest that blast exposure triggers release of LPAs, which play a major role promoting blast-induced ocular injuries, and that a single early administration of anti-LPA antibodies provides significant protection.
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Affiliation(s)
- Peethambaran Arun
- Blast-Induced Neurotrauma Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Franco Rossetti
- Blast-Induced Neurotrauma Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - James C DeMar
- Blast-Induced Neurotrauma Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Ying Wang
- Blast-Induced Neurotrauma Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Andrew B Batuure
- Blast-Induced Neurotrauma Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Donna M Wilder
- Blast-Induced Neurotrauma Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Irene D Gist
- Blast-Induced Neurotrauma Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Andrew J Morris
- Division of Cardiovascular Medicine, Lexington VA Medical Center, College of Medicine, University of Kentucky, Lexington, KY, United States
| | - Roger A Sabbadini
- Department of Biology, San Diego State University, San Diego, CA, United States
| | - Joseph B Long
- Blast-Induced Neurotrauma Branch, Walter Reed Army Institute of Research, Silver Spring, MD, United States
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21
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Sajja VS, Statz JK, Walker LPB, Gist ID, Wilder DM, Ahlers ST, Long JB. Pulmonary injury risk curves and behavioral changes from blast overpressure exposures of varying frequency and intensity in rats. Sci Rep 2020; 10:16644. [PMID: 33024181 PMCID: PMC7538583 DOI: 10.1038/s41598-020-73643-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 09/07/2020] [Indexed: 02/06/2023] Open
Abstract
At present, there are no set guidelines establishing cumulative limits for blast exposure numbers and intensities in military personnel, in combat or training operations. The objective of the current study was to define lung injury, pathology, and associated behavioral changes from primary repeated blast lung injury under appropriate exposure conditions and combinations (i.e. blast overpressure (BOP) intensity and exposure frequency) using an advanced blast simulator. Male Sprague Dawley rats were exposed to BOP frontally and laterally at a pressure range of ~ 8.5-19 psi, for up to 30 daily exposures. The extent of lung injury was identified at 24 h following BOP by assessing the extent of surface hemorrhage/contusion, Hematoxylin and Eosin staining, and behavioral deficits with open field activity. Lung injury was mathematically modeled to define the military standard 1% lung injury threshold. Significant levels of histiocytosis and inflammation were observed in pressures ≥ 10 psi and orientation effects were observed at pressures ≥ 13 psi. Experimental data demonstrated ~ 8.5 psi is the threshold for hemorrhage/contusion, up to 30 exposures. Modeling the data predicted injury risk up to 50 exposures with intensity thresholds at 8 psi for front exposure and 6psi for side exposures, which needs to be validated further.
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Affiliation(s)
- Venkatasivasai Sujith Sajja
- Blast Induced Neurotrauma Branch, Center for Military Psychiatry and Neurosciences, Walter Reed Army Institute of Research, Silver Spring, MD, USA. .,The Geneva Foundation, Tacoma, WA, USA.
| | - Jonathan K Statz
- Neurotrauma Department, Naval Medical Research Center, Silver Spring, MD, USA.,The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA
| | - Lcdr Peter B Walker
- Neurotrauma Department, Naval Medical Research Center, Silver Spring, MD, USA
| | - Irene D Gist
- Blast Induced Neurotrauma Branch, Center for Military Psychiatry and Neurosciences, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Donna M Wilder
- Blast Induced Neurotrauma Branch, Center for Military Psychiatry and Neurosciences, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Stephen T Ahlers
- Neurotrauma Department, Naval Medical Research Center, Silver Spring, MD, USA
| | - Joseph B Long
- Blast Induced Neurotrauma Branch, Center for Military Psychiatry and Neurosciences, Walter Reed Army Institute of Research, Silver Spring, MD, USA
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22
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McCabe JT, Tucker LB. Sex as a Biological Variable in Preclinical Modeling of Blast-Related Traumatic Brain Injury. Front Neurol 2020; 11:541050. [PMID: 33101170 PMCID: PMC7554632 DOI: 10.3389/fneur.2020.541050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 08/14/2020] [Indexed: 12/14/2022] Open
Abstract
Approaches to furthering our understanding of the bioeffects, behavioral changes, and treatment options following exposure to blast are a worldwide priority. Of particular need is a more concerted effort to employ animal models to determine possible sex differences, which have been reported in the clinical literature. In this review, clinical and preclinical reports concerning blast injury effects are summarized in relation to sex as a biological variable (SABV). The review outlines approaches that explore the pertinent role of sex chromosomes and gonadal steroids for delineating sex as a biological independent variable. Next, underlying biological factors that need exploration for blast effects in light of SABV are outlined, including pituitary, autonomic, vascular, and inflammation factors that all have evidence as having important SABV relevance. A major second consideration for the study of SABV and preclinical blast effects is the notable lack of consistent model design—a wide range of devices have been employed with questionable relevance to real-life scenarios—as well as poor standardization for reporting of blast parameters. Hence, the review also provides current views regarding optimal design of shock tubes for approaching the problem of primary blast effects and sex differences and outlines a plan for the regularization of reporting. Standardization and clear description of blast parameters will provide greater comparability across models, as well as unify consensus for important sex difference bioeffects.
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Affiliation(s)
- Joseph T McCabe
- Pre-clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Bethesda, IL, United States.,Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Laura B Tucker
- Pre-clinical Studies Core, Center for Neuroscience and Regenerative Medicine, Bethesda, IL, United States.,Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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23
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Wang Y, Urioste RT, Wei Y, Wilder DM, Arun P, Sajja V, Gist ID, Fitzgerald TS, Chang W, Kelley MW, Long JB. Blast-induced hearing impairment in rats is associated with structural and molecular changes of the inner ear. Sci Rep 2020; 10:10652. [PMID: 32606369 PMCID: PMC7327022 DOI: 10.1038/s41598-020-67389-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/29/2020] [Indexed: 02/08/2023] Open
Abstract
Auditory dysfunction is the most prevalent injury associated with blast overpressure exposure (BOP) in Warfighters and civilians, yet little is known about the underlying pathophysiological mechanisms. To gain insights into these injuries, an advanced blast simulator was used to expose rats to BOP and assessments were made to identify structural and molecular changes in the middle/inner ears utilizing otoscopy, RNA sequencing (RNA-seq), and histopathological analysis. Deficits persisting up to 1 month after blast exposure were observed in the distortion product otoacoustic emissions (DPOAEs) and the auditory brainstem responses (ABRs) across the entire range of tested frequencies (4–40 kHz). During the recovery phase at sub-acute time points, low frequency (e.g. 4–8 kHz) hearing improved relatively earlier than for high frequency (e.g. 32–40 kHz). Perforation of tympanic membranes and middle ear hemorrhage were observed at 1 and 7 days, and were restored by day 28 post-blast. A total of 1,158 differentially expressed genes (DEGs) were significantly altered in the cochlea on day 1 (40% up-regulated and 60% down-regulated), whereas only 49 DEGs were identified on day 28 (63% up-regulated and 37% down-regulated). Seven common DEGs were identified at both days 1 and 28 following blast, and are associated with inner ear mechanotransduction, cytoskeletal reorganization, myelin development and axon survival. Further studies on altered gene expression in the blast-injured rat cochlea may provide insights into new therapeutic targets and approaches to prevent or treat similar cases of blast-induced auditory damage in human subjects.
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Affiliation(s)
- Ying Wang
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA.
| | - Rodrigo T Urioste
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | - Yanling Wei
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | - Donna M Wilder
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | - Peethambaran Arun
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | - Venkatasivasaisujith Sajja
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | - Irene D Gist
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA
| | | | - Weise Chang
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders (NIDCD), Bethesda, MD, USA
| | - Matthew W Kelley
- Section on Developmental Neuroscience, National Institute on Deafness and Other Communication Disorders (NIDCD), Bethesda, MD, USA
| | - Joseph B Long
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Bethesda, MD, USA.
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24
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Kumar R, Nedungadi A. Using Gas-Driven Shock Tubes to Produce Blast Wave Signatures. Front Neurol 2020; 11:90. [PMID: 32153491 PMCID: PMC7047208 DOI: 10.3389/fneur.2020.00090] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 01/24/2020] [Indexed: 11/13/2022] Open
Abstract
The increased incidence of improvised explosives in military conflicts has brought about an increase in the number of traumatic brain injuries (TBIs) observed. Although physical injuries are caused by shrapnel and the immediate blast, encountering the blast wave associated with improvised explosive devices (IEDs) may be the cause of traumatic brain injuries experienced by warfighters. Assessment of the effectiveness of personal protective equipment (PPE) to mitigate TBI requires understanding the interaction between blast waves and human bodies and the ability to replicate the pressure signatures caused by blast waves. Prior research has validated compression-driven shock tube designs as a laboratory method of generating representative pressure signatures, or Friedlander-shaped blast profiles; however, shock tubes can vary depending on their design parameters and not all shock tube designs generate acceptable pressure signatures. This paper presents a comprehensive numerical study of the effects of driver gas, driver (breech) length, and membrane burst pressure of a constant-area shock tube. Discrete locations in the shock tube were probed, and the blast wave evolution in time at these points was analyzed to determine the effect of location on the pressure signature. The results of these simulations are used as a basis for suggesting guidelines for obtaining desired blast profiles.
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Affiliation(s)
- Rubbel Kumar
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States.,Department of Aerospace Engineering, University of Maryland, College Park, MD, United States
| | - Ashish Nedungadi
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States
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25
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The evolution of secondary flow phenomena and their effect on primary shock conditions in shock tubes: Experimentation and numerical model. PLoS One 2020; 15:e0227125. [PMID: 31945083 PMCID: PMC6964877 DOI: 10.1371/journal.pone.0227125] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 12/12/2019] [Indexed: 01/28/2023] Open
Abstract
Compressed gas-driven shock tubes are widely used for laboratory simulation of primary blasts by accurately replicating pressure profiles measured in live-fire explosions. These investigations require sound characterization of the primary blast wave, including the temporal and spatial evolution of the static and dynamic components of the blast wave. The goal of this work is to characterize the propagation of shock waves in and around the exit of a shock tube via analysis of the primary shock flow, including shock wave propagation and decay of the shock front, and secondary flow phenomena. To this end, a nine-inch shock tube and a cylindrical sensing apparatus were used to determine incident and total pressures outside of the shock tube, highlighting the presence of additional flow phenomena. Blast overpressure, impulse, shock wave arrival times, positive phase duration, and shock wave planarity were examined using a finite element model of the system. The shock wave remained planar inside of the shock tube and lost its planarity upon exiting. The peak overpressure and pressure impulse decayed rapidly upon exit from the shock tube, reducing by 92–95%. The primary flow phenomenon, or the planar shock front, is observed within the shock tube, while two distinct flow phenomena are a result of the shock wave exiting the confines of the shock tube. A vortex ring is formed as the shock wave exited the shock tube into the still, ambient air, which induces a large increase in the total pressure impulse. Additionally, a rarefaction wave was formed following shock front expansion, which traveled upstream into the shock tube, reducing the total and incident pressure impulses for approximately half of the simulated region.
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26
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Arun P, Wilder DM, Eken O, Urioste R, Batuure A, Sajja S, Van Albert S, Wang Y, Gist ID, Long JB. Long-Term Effects of Blast Exposure: A Functional Study in Rats Using an Advanced Blast Simulator. J Neurotrauma 2019; 37:647-655. [PMID: 31595810 DOI: 10.1089/neu.2019.6591] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Anecdotal observations of blast victims indicate that significant neuropathological and neurobehavioral defects may develop at later stages of life. To pre-clinically model this phenomenon, we have examined neurobehavioral changes in rats up to 1 year after exposure to single and tightly coupled repeated blasts using an advanced blast simulator. Neurobehavioral changes were monitored at acute, sub-acute, and chronic time-points using Morris water maze test of spatial learning and memory, novel object recognition test of short-term memory, open field exploratory activity as a test of anxiety/depression, a rotating pole test for vestibulomotor function, and a rotarod balance test for motor coordination. Single and repeated blasts resulted in significant functional deficits at both acute and chronic time-points. In most functional tests, rats exposed to repeated blasts performed more poorly than rats exposed to single blast. Interestingly, several functional deficits post-blast were most pronounced at 6 months and beyond. Significant neuromotor impairments occurred at early stages after blast exposure and the severity increased with repeated exposures. The novel object recognition testing revealed short-term memory deficits at 6 and 12 months post-blast. The water maze test revealed impairments at acute and chronic stages after blast exposure. The most substantial changes in the blast-exposed rats were observed with the center time and margin time legacies in the open field exploration test at 6, 9, and 12 months post-blast. Notably, these two outcome measures were minimally altered acutely, recovered during sub-acute stages, and were markedly affected during the chronic stages after blast exposures and may implicate development of chronic anxiety and depressive-like behaviors.
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Affiliation(s)
- Peethambaran Arun
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Donna M Wilder
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Ondine Eken
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Rodrigo Urioste
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Andrew Batuure
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Sujith Sajja
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Stephen Van Albert
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Ying Wang
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Irene D Gist
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Joseph B Long
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland
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27
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Jaiswal S, Knutsen AK, Wilson CM, Fu AH, Tucker LB, Kim Y, Bittner KC, Whiting MD, McCabe JT, Dardzinski BJ. Mild traumatic brain injury induced by primary blast overpressure produces dynamic regional changes in [18F]FDG uptake. Brain Res 2019; 1723:146400. [DOI: 10.1016/j.brainres.2019.146400] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 07/18/2019] [Accepted: 08/20/2019] [Indexed: 10/26/2022]
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28
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Harper MM, Woll AW, Evans LP, Delcau M, Akurathi A, Hedberg-Buenz A, Soukup DA, Boehme N, Hefti MM, Dutca LM, Anderson MG, Bassuk AG. Blast Preconditioning Protects Retinal Ganglion Cells and Reveals Targets for Prevention of Neurodegeneration Following Blast-Mediated Traumatic Brian Injury. Invest Ophthalmol Vis Sci 2019; 60:4159-4170. [PMID: 31598627 PMCID: PMC6785841 DOI: 10.1167/iovs.19-27565] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 08/22/2019] [Indexed: 12/13/2022] Open
Abstract
Purpose The purpose of this study was to examine the effect of multiple blast exposures and blast preconditioning on the structure and function of retinal ganglion cells (RGCs), to identify molecular pathways that contribute to RGC loss, and to evaluate the role of kynurenine-3-monooxygenase (KMO) inhibition on RGC structure and function. Methods Mice were subjected to sham blast injury, one single blast injury, or three blast injuries separated by either 1 hour or 1 week, using a blast intensity of 20 PSI. To examine the effect of blast preconditioning, mice were subjected to sham blast injury, one single 20-PSI injury, or three blast injuries separated by 1 week (5 PSI, 5 PSI, 20 PSI and 5 PSI, 5 PSI, 5 PSI). RGC structure was analyzed by optical coherence tomography (OCT) and function was analyzed by the pattern electroretinogram (PERG). BRN3A-positive cells were quantified to determine RGC density. RNA-seq analysis was used to identify transcriptional changes between groups. Results Analysis of mice with multiple blast exposures of 20 PSI revealed no significant differences compared to one 20-pounds per square inch (PSI) exposure using OCT, PERG, or BRN3A cell counts. Analysis of mice exposed to two preconditioning 5-PSI blasts prior to one 20-PSI blast showed preservation of RGC structure and function. RNA-seq analysis of the retina identified multiple transcriptomic changes between conditions. Pharmacologic inhibition of KMO preserved RGC responses compared to vehicle-treated mice. Conclusions Preconditioning protects RGC from blast injury. Protective effects appear to involve changes in KMO activity, whose inhibition is also protective.
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Affiliation(s)
- Matthew M. Harper
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Addison W. Woll
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Lucy P. Evans
- Medical Scientist Training Program, University of Iowa, Iowa City, Iowa, United States
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States
| | - Michael Delcau
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Abhigna Akurathi
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa
| | - Adam Hedberg-Buenz
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, United States
| | - Dana A. Soukup
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, United States
| | - Nickolas Boehme
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Marco M. Hefti
- Department of Pathology, University of Iowa, Iowa City, Iowa, United States
| | - Laura M. Dutca
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Michael G. Anderson
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, United States
| | - Alexander G. Bassuk
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States
- Department of Neurology, University of Iowa, Iowa City, Iowa, United States
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29
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30
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Transient disruption of mouse home cage activities and assessment of orexin immunoreactivity following concussive- or blast-induced brain injury. Brain Res 2018; 1700:138-151. [DOI: 10.1016/j.brainres.2018.08.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 11/21/2022]
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31
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Brady RD, Casillas-Espinosa PM, Agoston DV, Bertram EH, Kamnaksh A, Semple BD, Shultz SR. Modelling traumatic brain injury and posttraumatic epilepsy in rodents. Neurobiol Dis 2018; 123:8-19. [PMID: 30121231 DOI: 10.1016/j.nbd.2018.08.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 07/25/2018] [Accepted: 08/13/2018] [Indexed: 12/14/2022] Open
Abstract
Posttraumatic epilepsy (PTE) is one of the most debilitating and understudied consequences of traumatic brain injury (TBI). It is challenging to study the effects, underlying pathophysiology, biomarkers, and treatment of TBI and PTE purely in human patients for a number of reasons. Rodent models can complement human PTE studies as they allow for the rigorous investigation into the causal relationship between TBI and PTE, the pathophysiological mechanisms of PTE, the validation and implementation of PTE biomarkers, and the assessment of PTE treatments, in a tightly controlled, time- and cost-efficient manner in experimental subjects known to be experiencing epileptogenic processes. This article will review several common rodent models of TBI and/or PTE, including their use in previous studies and discuss their relative strengths, limitations, and avenues for future research to advance our understanding and treatment of PTE.
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Affiliation(s)
- Rhys D Brady
- Departments of Neuroscience and Medicine, Central Clinical School, Monash University, VIC 3004, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia.
| | - Pablo M Casillas-Espinosa
- Departments of Neuroscience and Medicine, Central Clinical School, Monash University, VIC 3004, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia.
| | - Denes V Agoston
- Anatomy, Physiology & Genetics, Uniformed Services University, Bethesda, MD 20814, USA
| | - Edward H Bertram
- Department of Neurology, University of Virginia, P.O. Box 800394, Charlottesville, VA 22908-0394, USA
| | - Alaa Kamnaksh
- Anatomy, Physiology & Genetics, Uniformed Services University, Bethesda, MD 20814, USA
| | - Bridgette D Semple
- Departments of Neuroscience and Medicine, Central Clinical School, Monash University, VIC 3004, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia
| | - Sandy R Shultz
- Departments of Neuroscience and Medicine, Central Clinical School, Monash University, VIC 3004, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia
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32
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Kawa L, Kamnaksh A, Long JB, Arborelius UP, Hökfelt T, Agoston DV, Risling M. A Comparative Study of Two Blast-Induced Traumatic Brain Injury Models: Changes in Monoamine and Galanin Systems Following Single and Repeated Exposure. Front Neurol 2018; 9:479. [PMID: 29973912 PMCID: PMC6019469 DOI: 10.3389/fneur.2018.00479] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 06/01/2018] [Indexed: 12/28/2022] Open
Abstract
Repeated mild blast-induced traumatic brain injury (rmbTBI), caused by recurrent exposure to low levels of explosive blast, is a significant concern for military health systems. However, the pathobiology of rmbTBI is currently poorly understood. Animal models are important tools to identify the molecular changes of rmbTBI, but comparisons across different models can present their own challenges. In this study, we compared two well-established rodent models of mbTBI, the "KI model" and the "USU/WRAIR model." These two models create different pulse forms, in terms of peak pressure and duration. Following single and double exposures to mild levels of blast, we used in situ hybridization (ISH) to assess changes in mRNA levels of tyrosine hydroxylase (TH), tryptophan hydroxylase (TPH2), and galanin in the locus coeruleus (LC) and dorsal raphe nucleus (DRN). These systems and their transmitters are known to mediate responses to stress and anxiety. We found increased mRNA levels of TH, TPH2 and galanin in the LC and DRN of single-exposed rats relative to sham rats in the KI but not the USU/WRAIR model. Sham mRNA values measured in the USU/WRAIR model were substantially higher than their KI counterparts. Double exposure caused similarly significant increases in mRNA values in the KI model but not the USU/WRAIR model, except TPH2 and galanin levels in the DRN. We detected no cumulative effect of injury in either model at the used inter-injury interval (30 min), and there were no detectable neuropathological changes in any experimental group at 1 day post-injury. The apparent lack of early response to injury as compared to sham in the USU/WRAIR model is likely caused by stressors (e.g., transportation and noise), associated with the experimental execution, that were absent in the KI model. This study is the first to directly compare two established rodent models of rmbTBI, and to highlight the challenges of comparing findings from different animal models. Additional studies are needed to understand the role of stress, dissect the effects of psychological and physical injuries and to identify the window of increased cerebral vulnerability, i.e., the inter-injury interval that results in a cumulative effect following repeated blast exposure.
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Affiliation(s)
- Lizan Kawa
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Alaa Kamnaksh
- Department of Anatomy, Physiology and Genetics, Uniformed Services, University, Bethesda, MD, United States
| | - Joseph B Long
- Blast-Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Ulf P Arborelius
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Tomas Hökfelt
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Denes V Agoston
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Anatomy, Physiology and Genetics, Uniformed Services, University, Bethesda, MD, United States
| | - Mårten Risling
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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Skotak M, Alay E, Zheng JQ, Halls V, Chandra N. Effective testing of personal protective equipment in blast loading conditions in shock tube: Comparison of three different testing locations. PLoS One 2018; 13:e0198968. [PMID: 29894521 PMCID: PMC5997325 DOI: 10.1371/journal.pone.0198968] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 05/28/2018] [Indexed: 11/18/2022] Open
Abstract
We exposed a headform instrumented with 10 pressure sensors mounted flush with the surface to a shock wave with three nominal intensities: 70, 140 and 210 kPa. The headform was mounted on a Hybrid III neck, in a rigid configuration to eliminate motion and associated pressure variations. We evaluated the effect of the test location by placing the headform inside, at the end and outside of the shock tube. The shock wave intensity gradually decreases the further it travels in the shock tube and the end effect degrades shock wave characteristics, which makes comparison of the results obtained at three locations a difficult task. To resolve these issues, we developed a simple strategy of data reduction: the respective pressure parameters recorded by headform sensors were divided by their equivalents associated with the incident shock wave. As a result, we obtained a comprehensive set of non-dimensional parameters. These non-dimensional parameters (or amplification factors) allow for direct comparison of pressure waveform characteristic parameters generated by a range of incident shock waves differing in intensity and for the headform located in different locations. Using this approach, we found a correlation function which allows prediction of the peak pressure on the headform that depends only on the peak pressure of the incident shock wave (for specific sensor location on the headform), and itis independent on the headform location. We also found a similar relationship for the rise time. However, for the duration and impulse, comparable correlation functions do not exist. These findings using a headform with simplified geometry are baseline values and address a need for the development of standardized parameters for the evaluation of personal protective equipment (PPE) under shock wave loading.
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Affiliation(s)
- Maciej Skotak
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States of America
- * E-mail: (MS); (NC)
| | - Eren Alay
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States of America
| | - James Q. Zheng
- Program Executive Office—Soldier, United States Army, Fort Belvoir, VA, United States of America
| | - Virginia Halls
- Program Executive Office—Soldier, United States Army, Fort Belvoir, VA, United States of America
| | - Namas Chandra
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States of America
- * E-mail: (MS); (NC)
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34
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Kuriakose M, Rama Rao KV, Younger D, Chandra N. Temporal and Spatial Effects of Blast Overpressure on Blood-Brain Barrier Permeability in Traumatic Brain Injury. Sci Rep 2018; 8:8681. [PMID: 29875451 PMCID: PMC5989233 DOI: 10.1038/s41598-018-26813-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 05/01/2018] [Indexed: 12/13/2022] Open
Abstract
Blast-induced traumatic brain injury (bTBI) is a “signature wound” in soldiers during training and in combat and has also become a major cause of morbidity in civilians due to increased insurgency. This work examines the role of blood-brain barrier (BBB) disruption as a result of both primary biomechanical and secondary biochemical injury mechanisms in bTBI. Extravasation of sodium fluorescein (NaF) and Evans blue (EB) tracers were used to demonstrate that compromise of the BBB occurs immediately following shock loading, increases in intensity up to 4 hours and returns back to normal in 24 hours. This BBB compromise occurs in multiple regions of the brain in the anterior-posterior direction of the shock wave, with maximum extravasation seen in the frontal cortex. Compromise of the BBB is confirmed by (a) extravasation of tracers into the brain, (b) quantification of tight-junction proteins (TJPs) in the brain and the blood, and (c) tracking specific blood-borne molecules into the brain and brain-specific proteins into the blood. Taken together, this work demonstrates that the BBB compromise occurs as a part of initial biomechanical loading and is a function of increasing blast overpressures.
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Affiliation(s)
- Matthew Kuriakose
- Center for Injury Biomechanics, Materials and Medicine (CIBM3), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102-1982, USA
| | - Kakulavarapu V Rama Rao
- Center for Injury Biomechanics, Materials and Medicine (CIBM3), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102-1982, USA.
| | - Daniel Younger
- Center for Injury Biomechanics, Materials and Medicine (CIBM3), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102-1982, USA
| | - Namas Chandra
- Center for Injury Biomechanics, Materials and Medicine (CIBM3), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102-1982, USA.
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35
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Salat DH, Robinson ME, Miller DR, Clark DC, McGlinchey RE. Neuroimaging of deployment-associated traumatic brain injury (TBI) with a focus on mild TBI (mTBI) since 2009. Brain Inj 2018; 31:1204-1219. [PMID: 28981347 DOI: 10.1080/02699052.2017.1327672] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES A substantial body of recent research has aimed to better understand the clinical sequelae of military trauma through the application of advanced brain imaging procedures in Veteran populations. The primary objective of this review was to highlight a portion of these recent studies to demonstrate how imaging tools can be used to understand military-associated brain injury. METHODS We focus here on the phenomenon of mild traumatic brain injury (mTBI) given its high prevalence in the Veteran population and current recognition of the need to better understand the clinical implications of this trauma. This is intended to provide readers with an initial exposure to the field of neuroimaging of mTBI with a brief introduction to the concept of traumatic brain injury, followed by a summary of the major imaging techniques that have been applied to the study of mTBI. RESULTS Taken together, the collection of studies reviewed demonstrates a clear role for neuroimaging towards understanding the various neural consequences of mTBI as well as the clinical complications of such brain changes. CONCLUSIONS This information must be considered in the larger context of research into mTBI, including the potentially unique nature of blast exposure and the long-term consequences of mTBI.
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Affiliation(s)
- David H Salat
- a Neuroimaging Research for Veterans (NeRVe) Center , VA Boston Healthcare System , Boston , MA , USA.,b Athinoula A. Martinos Center for Biomedical Imaging , Massachusetts General Hospital Department of Radiology , Charlestown , MA , USA.,c Translational Research Center for TBI and Stress Disorders (TRACTS) , VA Boston Healthcare System , Boston , MA , USA
| | - Meghan E Robinson
- a Neuroimaging Research for Veterans (NeRVe) Center , VA Boston Healthcare System , Boston , MA , USA.,c Translational Research Center for TBI and Stress Disorders (TRACTS) , VA Boston Healthcare System , Boston , MA , USA.,d Department of Neurology , Boston University School of Medicine , Boston , MA , USA
| | - Danielle R Miller
- e National Center for PTSD , VA Boston Healthcare System , Boston , MA , USA.,f Department of Psychiatry , Boston University School of Medicine , Boston , MA , USA
| | - Dustin C Clark
- a Neuroimaging Research for Veterans (NeRVe) Center , VA Boston Healthcare System , Boston , MA , USA
| | - Regina E McGlinchey
- c Translational Research Center for TBI and Stress Disorders (TRACTS) , VA Boston Healthcare System , Boston , MA , USA.,g Geriatric Research , Education and Clinical Center (GRECC) , Boston , MA , USA.,h Department of Psychiatry , Harvard Medical School , Boston , MA , USA
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36
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Sandlin DS, Yu Y, Huang J, Zhang C, Arteaga AA, Lippincott JK, Peeden EO, Guyton RR, Chen L, Beneke LL, Allison JC, Zhu H, Zhou W. Autonomic responses to blast overpressure can be elicited by exclusively exposing the ear in rats. J Otol 2018; 13:44-53. [PMID: 30559764 PMCID: PMC6291641 DOI: 10.1016/j.joto.2018.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 01/28/2018] [Accepted: 01/30/2018] [Indexed: 11/29/2022] Open
Abstract
Blast overpressure has become an increasing cause of brain injuries in both military and civilian populations. Though blast's direct effects on the cochlea and vestibular organs are active areas of study, little attention has been given to the ear's contribution to the overall spectrum of blast injury. Acute autonomic responses to blast exposure, including bradycardia and hypotension, can cause hypoxia and contribute to blast-induced neurotrauma. Existing literature suggests that these autonomic responses are elicited through blast impacting the thorax and lungs. We hypothesize that the unprotected ear also provides a vulnerable locus for blast to cause autonomic responses. We designed a blast generator that delivers controlled overpressure waves into the ear canal without impacting surrounding tissues in order to study the ear's specific contribution to blast injury. Anesthetized adult rats' left ears were exposed to a single blast wave ranging from 0 to 110 PSI (0-758 kPa). Blast exposed rats exhibited decreased heart rates and blood pressures with increased blast intensity, similar to results gathered using shock tubes and whole-body exposure in the literature. While rats exposed to blasts below 50 PSI (345 kPa) exhibited increased respiratory rate with increased blast intensity, some rats exposed to blasts higher than 50 PSI (345 kPa) stopped breathing immediately and ultimately died. These autonomic responses were significantly reduced in vagally denervated rats, again similar to whole-body exposure literature. These results support the hypothesis that the unprotected ear contributes to the autonomic responses to blast.
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Affiliation(s)
- David S. Sandlin
- Graduate Program in Neuroscience, University of Mississippi Medical Center, Jackson, MS, USA
- School of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Yue Yu
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Jun Huang
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Chunming Zhang
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
- Department of Otolaryngology, First Affiliated Hospital, Shanxi Medical University, 85 Jiefang S Rd, Yingze Qu, Taiyuan Shi, Shanxi Sheng, China
| | - Alberto A. Arteaga
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - John K. Lippincott
- School of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Erin O.H. Peeden
- School of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Ryan R. Guyton
- Graduate Program in Neuroscience, University of Mississippi Medical Center, Jackson, MS, USA
| | - Lan Chen
- Summer Undergraduate Research Experience, University of Mississippi Medical Center, Jackson, MS, USA
| | - Laura L.S. Beneke
- School of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - Jerome C. Allison
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Hong Zhu
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, USA
| | - Wu Zhou
- Department of Otolaryngology and Communicative Sciences, University of Mississippi Medical Center, Jackson, MS, USA
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, USA
- Department of Neurology, University of Mississippi Medical Center, Jackson, MS, USA
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37
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Agoston DV. Modeling the Long-Term Consequences of Repeated Blast-Induced Mild Traumatic Brain Injuries. J Neurotrauma 2018; 34:S44-S52. [PMID: 28937952 DOI: 10.1089/neu.2017.5317] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Repeated mild traumatic brain injury (rmTBI) caused by playing collision sports or by exposure to blasts during military operations can lead to late onset, chronic diseases such as chronic traumatic encephalopathy (CTE), a progressive neurodegenerative condition that manifests in increasingly severe neuropsychiatric abnormalities years after the last injury. Currently, because of the heterogeneity of the clinical presentation, confirmation of a CTE diagnosis requires post-mortem examination of the brain. The hallmarks of CTE are abnormal accumulation of phosphorylated tau protein, TDP-43 immunoreactive neuronal cytoplasmic inclusions, and astroglial abnormalities, but the pathomechanism leading to these terminal findings remains unknown. Animal modeling can play an important role in the identification of CTE pathomechanisms, the development of early stage diagnostic and prognostic biomarkers, and pharmacological interventions. Modeling the long-term consequences of blast rmTBI in animals is especially challenging because of the complexities of blast physics and animal-to-human scaling issues. This review summarizes current knowledge about the pathobiologies of CTE and rmbTBI and discusses problems as well as potential solutions related to high-fidelity modeling of rmbTBI and determining its long-term consequences.
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Affiliation(s)
- Denes V Agoston
- Department of Anatomy, Physiology and Genetics, Uniformed Services University , Bethesda, Maryland; Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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38
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Song H, Cui J, Simonyi A, Johnson CE, Hubler GK, DePalma RG, Gu Z. Linking blast physics to biological outcomes in mild traumatic brain injury: Narrative review and preliminary report of an open-field blast model. Behav Brain Res 2018; 340:147-158. [DOI: 10.1016/j.bbr.2016.08.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 08/13/2016] [Accepted: 08/19/2016] [Indexed: 12/14/2022]
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39
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Sawyer TW, Ritzel DV, Wang Y, Josey T, Villanueva M, Nelson P, Song Y, Shei Y, Hennes G, Vair C, Parks S, Fan C, McLaws L. Primary Blast Causes Delayed Effects without Cell Death in Shell-Encased Brain Cell Aggregates. J Neurotrauma 2017; 35:174-186. [PMID: 28726571 DOI: 10.1089/neu.2016.4961] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Previous work in this laboratory used underwater explosive exposures to isolate the effects of shock-induced principle stress without shear on rat brain aggregate cultures. The current study has utilized simulated air blast to expose aggregates in suspension and enclosed within a spherical shell, enabling the examination of a much more complex biomechanical insult. Culture medium-filled spheres were exposed to single pulse overpressures of 15-30 psi (∼6-7 msec duration) and measurements within the sphere at defined sites showed complex and spatially dependent pressure changes. When brain aggregates were exposed to similar conditions, no cell death was observed and no changes in several commonly used biomarkers of traumatic brain injury (TBI) were noted. However, similarly to underwater blast, immediate and transient increases in the protein kinase B signaling pathway were observed at early time-points (3 days). In contrast, the oligodendrocyte marker 2',3'-cyclic nucleotide 3'-phosphodiesterase, as well as vascular endothelial growth factor, both displayed markedly delayed (14-28 days) and pressure-dependent responses. The imposition of a spherical shell between the single pulse shock wave and the target brain tissue introduces greatly increased complexity to the insult. This work shows that brain tissue can not only discriminate the nature of the pressure changes it experiences, but that a portion of its response is significantly delayed. These results have mechanistic implications for the study of primary blast-induced TBI and also highlight the importance of rigorously characterizing the actual pressure variations experienced by target tissue in primary blast studies.
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Affiliation(s)
- Thomas W Sawyer
- 1 Defence Research and Development Canada, Suffield Research Center , Medicine Hat, Alberta, Canada
| | | | - Yushan Wang
- 1 Defence Research and Development Canada, Suffield Research Center , Medicine Hat, Alberta, Canada
| | - Tyson Josey
- 1 Defence Research and Development Canada, Suffield Research Center , Medicine Hat, Alberta, Canada
| | - Mercy Villanueva
- 1 Defence Research and Development Canada, Suffield Research Center , Medicine Hat, Alberta, Canada
| | - Peggy Nelson
- 1 Defence Research and Development Canada, Suffield Research Center , Medicine Hat, Alberta, Canada
| | - Yanfeng Song
- 1 Defence Research and Development Canada, Suffield Research Center , Medicine Hat, Alberta, Canada
| | - Yimin Shei
- 1 Defence Research and Development Canada, Suffield Research Center , Medicine Hat, Alberta, Canada
| | - Grant Hennes
- 1 Defence Research and Development Canada, Suffield Research Center , Medicine Hat, Alberta, Canada
| | - Cory Vair
- 1 Defence Research and Development Canada, Suffield Research Center , Medicine Hat, Alberta, Canada
| | | | - Changyang Fan
- 4 Canada West Biosciences , Camrose, Alberta, Canada
| | - Lori McLaws
- 1 Defence Research and Development Canada, Suffield Research Center , Medicine Hat, Alberta, Canada
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40
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Hypothermia Prevents Retinal Damage Generated by Optic Nerve Trauma in the Rat. Sci Rep 2017; 7:6966. [PMID: 28761115 PMCID: PMC5537267 DOI: 10.1038/s41598-017-07294-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 06/26/2017] [Indexed: 11/11/2022] Open
Abstract
Ocular and periocular traumatisms may result in loss of vision. Hypothermia provides a beneficial intervention for brain and heart conditions and, here, we study whether hypothermia can prevent retinal damage caused by traumatic neuropathy. Intraorbital optic nerve crush (IONC) or sham manipulation was applied to male rats. Some animals were subjected to hypothermia (8 °C) for 3 h following surgery. Thirty days later, animals were subjected to electroretinography and behavioral tests. IONC treatment resulted in amplitude reduction of the b-wave and oscillatory potentials of the electroretinogram, whereas the hypothermic treatment significantly (p < 0.05) reversed this process. Using a descending method of limits in a two-choice visual task apparatus, we demonstrated that hypothermia significantly (p < 0.001) preserved visual acuity. Furthermore, IONC-treated rats had a lower (p < 0.0001) number of retinal ganglion cells and a higher (p < 0.0001) number of TUNEL-positive cells than sham-operated controls. These numbers were significantly (p < 0.0001) corrected by hypothermic treatment. There was a significant (p < 0.001) increase of RNA-binding motif protein 3 (RBM3) and of BCL2 (p < 0.01) mRNA expression in the eyes exposed to hypothermia. In conclusion, hypothermia constitutes an efficacious treatment for traumatic vision-impairing conditions, and the cold-shock protein pathway may be involved in mediating the beneficial effects shown in the retina.
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41
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Wojnarowicz MW, Fisher AM, Minaeva O, Goldstein LE. Considerations for Experimental Animal Models of Concussion, Traumatic Brain Injury, and Chronic Traumatic Encephalopathy-These Matters Matter. Front Neurol 2017; 8:240. [PMID: 28620350 PMCID: PMC5451508 DOI: 10.3389/fneur.2017.00240] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 05/16/2017] [Indexed: 12/14/2022] Open
Abstract
Animal models of concussion, traumatic brain injury (TBI), and chronic traumatic encephalopathy (CTE) are widely available and routinely deployed in laboratories around the world. Effective animal modeling requires careful consideration of four basic principles. First, animal model use must be guided by clarity of definitions regarding the human disease or condition being modeled. Concussion, TBI, and CTE represent distinct clinical entities that require clear differentiation: concussion is a neurological syndrome, TBI is a neurological event, and CTE is a neurological disease. While these conditions are all associated with head injury, the pathophysiology, clinical course, and medical management of each are distinct. Investigators who use animal models of these conditions must take into account these clinical distinctions to avoid misinterpretation of results and category mistakes. Second, model selection must be grounded by clarity of purpose with respect to experimental questions and frame of reference of the investigation. Distinguishing injury context ("inputs") from injury consequences ("outputs") may be helpful during animal model selection, experimental design and execution, and interpretation of results. Vigilance is required to rout out, or rigorously control for, model artifacts with potential to interfere with primary endpoints. The widespread use of anesthetics in many animal models illustrates the many ways that model artifacts can confound preclinical results. Third, concordance between key features of the animal model and the human disease or condition being modeled is required to confirm model biofidelity. Fourth, experimental results observed in animals must be confirmed in human subjects for model validation. Adherence to these principles serves as a bulwark against flawed interpretation of results, study replication failure, and confusion in the field. Implementing these principles will advance basic science discovery and accelerate clinical translation to benefit people affected by concussion, TBI, and CTE.
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Affiliation(s)
- Mark W Wojnarowicz
- Molecular Aging and Development Laboratory, Boston University School of Medicine, Boston, MA, United States
| | - Andrew M Fisher
- Molecular Aging and Development Laboratory, Boston University School of Medicine, Boston, MA, United States.,Boston University College of Engineering, Boston, MA, United States
| | - Olga Minaeva
- Molecular Aging and Development Laboratory, Boston University School of Medicine, Boston, MA, United States.,Boston University College of Engineering, Boston, MA, United States
| | - Lee E Goldstein
- Molecular Aging and Development Laboratory, Boston University School of Medicine, Boston, MA, United States.,Boston University College of Engineering, Boston, MA, United States.,CTE Program, Boston University Alzheimer's Disease Center, Boston, MA, United States
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42
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Internal Jugular Vein Compression: A Novel Approach to Mitigate Blast Induced Hearing Injury. Otol Neurotol 2017; 38:591-598. [DOI: 10.1097/mao.0000000000001332] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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43
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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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44
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Feng K, Zhang L, Jin X, Chen C, Kallakuri S, Saif T, Cavanaugh J, King A. Biomechanical Responses of the Brain in Swine Subject to Free-Field Blasts. Front Neurol 2016; 7:179. [PMID: 27822197 PMCID: PMC5075707 DOI: 10.3389/fneur.2016.00179] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 10/04/2016] [Indexed: 01/05/2023] Open
Abstract
Blast-induced traumatic brain injury (bTBI) is a signature wound of modern warfare. The current incomplete understanding of its injury mechanism impedes the development of strategies for effective protection of bTBI. Despite a considerable amount of experimental animal studies focused on the evaluation of brain neurotrauma caused by blast exposure, there is very limited knowledge on the biomechanical responses of the gyrenecephalic brain subjected to primary free-field blast waves imposed in vivo. This study aims to evaluate the external and internal mechanical responses of the brain against different levels of blast loading with Yucatan swine in free field. The incident overpressure (IOP) was generated using 3.6 kg of C4 charge placed at three standoff distances from the swine. Five swine were exposed to a total of 19 blasts. The three average peak IOP pressure levels in this study were 148.8, 278.9, and 409.2 kPa as measured by a pencil probe. The duration of the first positive wave was in the range of 2.1–3 ms. Pressure changes in the brain and head kinematics were recorded with intracranial pressure (ICP) sensors, linear accelerometers, and angular rate sensors. The corresponding average peak ICPs were in the range of 79–143, 210–281, and 311–414 kPa designated as low, medium, and high blast level, respectively. Peak head linear accelerations were in the range of 120–412 g. A positive correlation between IOP and its corresponding biomechanical responses of the brain was also observed. These experimental data can be used to validate computer models of bTBI.
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Affiliation(s)
- Ke Feng
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Liying Zhang
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Xin Jin
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Chaoyang Chen
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Srinivasu Kallakuri
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Tal Saif
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - John Cavanaugh
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Albert King
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
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Kuriakose M, Skotak M, Misistia A, Kahali S, Sundaramurthy A, Chandra N. Tailoring the Blast Exposure Conditions in the Shock Tube for Generating Pure, Primary Shock Waves: The End Plate Facilitates Elimination of Secondary Loading of the Specimen. PLoS One 2016; 11:e0161597. [PMID: 27603017 PMCID: PMC5014318 DOI: 10.1371/journal.pone.0161597] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 08/08/2016] [Indexed: 11/19/2022] Open
Abstract
The end plate mounted at the mouth of the shock tube is a versatile and effective implement to control and mitigate the end effects. We have performed a series of measurements of incident shock wave velocities and overpressures followed by quantification of impulse values (integral of pressure in time domain) for four different end plate configurations (0.625, 2, 4 inches, and an open end). Shock wave characteristics were monitored by high response rate pressure sensors allocated in six positions along the length of 6 meters long 229 mm square cross section shock tube. Tests were performed at three shock wave intensities, which was controlled by varying the Mylar membrane thickness (0.02, 0.04 and 0.06 inch). The end reflector plate installed at the exit of the shock tube allows precise control over the intensity of reflected waves penetrating into the shock tube. At the optimized distance of the tube to end plate gap the secondary waves were entirely eliminated from the test section, which was confirmed by pressure sensor at T4 location. This is pronounced finding for implementation of pure primary blast wave animal model. These data also suggest only deep in the shock tube experimental conditions allow exposure to a single shock wave free of artifacts. Our results provide detailed insight into spatiotemporal dynamics of shock waves with Friedlander waveform generated using helium as a driver gas and propagating in the air inside medium sized tube. Diffusion of driver gas (helium) inside the shock tube was responsible for velocity increase of reflected shock waves. Numerical simulations combined with experimental data suggest the shock wave attenuation mechanism is simply the expansion of the internal pressure. In the absence of any other postulated shock wave decay mechanisms, which were not implemented in the model the agreement between theory and experimental data is excellent.
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Affiliation(s)
- Matthew Kuriakose
- Center for Injury Biomechanics, Materials and Medicine (CIBM), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102–1982, United States of America
| | - Maciej Skotak
- Center for Injury Biomechanics, Materials and Medicine (CIBM), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102–1982, United States of America
| | - Anthony Misistia
- Center for Injury Biomechanics, Materials and Medicine (CIBM), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102–1982, United States of America
| | - Sudeepto Kahali
- Center for Injury Biomechanics, Materials and Medicine (CIBM), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102–1982, United States of America
| | - Aravind Sundaramurthy
- Center for Injury Biomechanics, Materials and Medicine (CIBM), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102–1982, United States of America
| | - Namas Chandra
- Center for Injury Biomechanics, Materials and Medicine (CIBM), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102–1982, United States of America
- * E-mail:
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46
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Wang H, Zhang YP, Cai J, Shields LBE, Tuchek CA, Shi R, Li J, Shields CB, Xu XM. A Compact Blast-Induced Traumatic Brain Injury Model in Mice. J Neuropathol Exp Neurol 2016; 75:183-96. [PMID: 26802177 DOI: 10.1093/jnen/nlv019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Blast-induced traumatic brain injury (bTBI) is a common injury on the battlefield and often results in permanent cognitive and neurological abnormalities. We report a novel compact device that creates graded bTBI in mice. The injury severity can be controlled by precise pressures that mimic Friedlander shockwave curves. The mouse head was stabilized with a head fixator, and the body was protected with a metal shield; shockwave durations were 3 to 4 milliseconds. Reflective shockwave peak readings at the position of the mouse head were 12 6 2.6 psi, 50 6 20.3 psi, and 100 6 33.1 psi at 100, 200, and 250 psi predetermined driver chamber pressures, respectively. The bTBIs of 250 psi caused 80% mortality, which decreased to 27% with the metal shield. Brain and lung damage depended on the shockwave duration and amplitude. Cognitive deficits were assessed using the Morris water maze, Y-maze, and open-field tests. Pathological changes in the brain included disruption of the blood-brain barrier, multifocal neuronal and axonal degeneration, and reactive gliosis assessed by Evans Blue dye extravasation, silver and Fluoro-Jade B staining, and glial fibrillary acidic protein immunohistochemistry, respectively. Behavioral and pathological changes were injury severity-dependent. This mouse bTBI model may be useful for investigating injury mechanisms and therapeutic strategies associated with bTBI.
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Zander NE, Piehler T, Banton R, Benjamin R. Effects of repetitive low-pressure explosive blast on primary neurons and mixed cultures. J Neurosci Res 2016; 94:827-36. [PMID: 27317559 DOI: 10.1002/jnr.23786] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 04/28/2016] [Accepted: 05/23/2016] [Indexed: 02/05/2023]
Abstract
Repetitive mild traumatic brain injury represents a considerable health concern, particularly for athletes and military personnel. For blast-induced brain injury, threshold shock-impulse levels required to induce such injuries and cumulative effects with single and/or multiple exposures are not well characterized. Currently, there is no established in vitro experimental model with blast pressure waves generated by live explosives. This study presents results of primary neurons and mixed cultures subjected to our unique in vitro indoor experimental platform that uses real military explosive charges to probe the effects of primary explosive blast at the cellular level. The effects of the blast on membrane permeability, generation of reactive oxygen species (ROS), uptake of sodium ions, intracellular calcium, and release of glutamate were probed 2 and 24 hr postblast. Significant changes in membrane permeability and sodium uptake among the sham, single-blast-injured, and triple-blast-injured samples were observed. A significant increase in ROS and glutamate release was observed for the triple-blast-injured samples compared with the sham. Changes in intracellular calcium were not significant. These results suggest that blast exposure disrupts the integrity of the plasma membrane, leading to the upset of ion homeostasis, formation of ROS, and glutamate release. Published 2016. †This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Nicole E Zander
- United States Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, Aberdeen, Maryland
| | - Thuvan Piehler
- United States Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, Aberdeen, Maryland
| | - Rohan Banton
- United States Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, Aberdeen, Maryland
| | - Richard Benjamin
- United States Army Research Laboratory, Weapons and Materials Research Directorate, Aberdeen Proving Ground, Aberdeen, Maryland
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48
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DeMar J, Sharrow K, Hill M, Berman J, Oliver T, Long J. Effects of Primary Blast Overpressure on Retina and Optic Tract in Rats. Front Neurol 2016; 7:59. [PMID: 27199884 PMCID: PMC4842954 DOI: 10.3389/fneur.2016.00059] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 04/08/2016] [Indexed: 12/19/2022] Open
Abstract
Blast has been the leading cause of injury, particularly traumatic brain injury and visual system injury, in combat operations in Iraq and Afghanistan. We determined the effect of shock tube-generated primary blast on retinal electrophysiology and on retinal and brain optic tract histopathology in a rat model. The amplitude of a- and b-waves on the electroretinogram (ERG) for both right and left eyes were measured prior to a battlefield simulation Friedlander-type blast wave and on 1, 7, and 14 days thereafter. Histopathologic findings of the right and left retina and the right and left optic tracts (2.8 mm postoptic chiasm) were evaluated 14 days after the blast. For two experiments in which the right eye was oriented to the blast, the amplitude of ERG a- and b-waves at 7 days post blast on the right side but not on the left side was diminished compared to that of sham animals (P = 0.005–0.01) Histopathologic injury scores at 14 days post blast for the right retina but not the left retina were higher than for sham animals (P = 0.01), and histopathologic injury scores at 14 days for both optic tracts were markedly higher than for shams (P < 0.0001). Exposure of one eye to a blast wave, comparable to that causing human injury, produced injury to the retina as determined by ERG and histopathology, and to both postchiasmatic optic tracts as determined by histopathology. This model may be useful for analyzing the effect of therapeutic interventions on retinal damage due to primary blast waves.
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Affiliation(s)
- James DeMar
- Blast Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research , Silver Spring, MD , USA
| | - Keith Sharrow
- Medical Countermeasures Systems, Ft. Detrick , Frederick, MD , USA
| | - Miya Hill
- Blast Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research , Silver Spring, MD , USA
| | - Jonathan Berman
- Clinical Pharmacology Department, Walter Reed Army Institute of Research , Silver Spring, MD , USA
| | - Thomas Oliver
- Clinical Research Unit, Uniformed Services University of the Health Science (USUHS) , Bethesda, MD , USA
| | - Joseph Long
- Blast Induced Neurotrauma Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research , Silver Spring, MD , USA
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49
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Tasissa AF, Hautefeuille M, Fitek JH, Radovitzky RA. On the formation of Friedlander waves in a compressed-gas-driven shock tube. Proc Math Phys Eng Sci 2016; 472:20150611. [PMID: 27118888 DOI: 10.1098/rspa.2015.0611] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Compressed-gas-driven shock tubes have become popular as a laboratory-scale replacement for field blast tests. The well-known initial structure of the Riemann problem eventually evolves into a shock structure thought to resemble a Friedlander wave, although this remains to be demonstrated theoretically. In this paper, we develop a semi-analytical model to predict the key characteristics of pseudo blast waves forming in a shock tube: location where the wave first forms, peak over-pressure, decay time and impulse. The approach is based on combining the solutions of the two different types of wave interactions that arise in the shock tube after the family of rarefaction waves in the Riemann solution interacts with the closed end of the tube. The results of the analytical model are verified against numerical simulations obtained with a finite volume method. The model furnishes a rational approach to relate shock tube parameters to desired blast wave characteristics, and thus constitutes a useful tool for the design of shock tubes for blast testing.
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Affiliation(s)
- Abiy F Tasissa
- Institute for Solider Nanotechnologies , Department of Aeronautics and Astronautics, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
| | - Martin Hautefeuille
- Institute for Solider Nanotechnologies , Department of Aeronautics and Astronautics, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
| | - John H Fitek
- US Army Natick Soldier Research , Development and Engineering Center , Natick, MA 01760, USA
| | - Raúl A Radovitzky
- Institute for Solider Nanotechnologies , Department of Aeronautics and Astronautics, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
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50
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Rusch HL, Gill JM. Effect of Acute Sleep Disturbance and Recovery on Insulin-Like Growth Factor-1 (IGF-1): Possible Connections and Clinical Implications. J Clin Sleep Med 2015; 11:1245-6. [PMID: 26414987 DOI: 10.5664/jcsm.5108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 08/21/2015] [Indexed: 11/13/2022]
Affiliation(s)
- Heather L Rusch
- National Institutes of Health, National Institute of Nursing Research.,Henry M. Jackson for the Advancement of Military Medicine
| | - Jessica M Gill
- National Institutes of Health, National Institute of Nursing Research
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