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21.
Sung H. Yang Josh Gustafson Matt Gangidine David Stepien Rebecca Schuster Timothy A. Pritts Michael D. Goodman Daniel G. Remick Alex B. Lentsch 《The Journal of surgical research》2013
Background
Mild traumatic brain injury (TBI) is a serious public health concern affecting more than 1.7 million people in the United States annually. Mild TBI is difficult to diagnose and is clinically associated with impaired motor coordination and cognition.Methods
We subjected mice to a mild TBI (mTBI-1 or mTBI-2) induced by a weight drop model. We assessed brain injury histologically and biochemically, the latter by serum neuron-specific enolase and glial fibrillary acidic protein. Systemic and brain inflammation were measured by cytokine array. We determined blood–brain barrier integrity by cerebral vascular leakage of micromolecular and macromolecular fluorescent molecules. We evaluated mice using a rotarod device and novel object recognition to measure motor coordination and cognition, respectively.Results
Mice undergoing mTBI-1 or mTBI-2 had significant deficits in motor coordination and cognition for several days after injury compared with controls. Furthermore, both mTBI-1 and mTBI-2 caused micromolecular leakage in the blood–brain barrier, whereas only mTBI-2 caused macromolecular leakage. Serum neuron-specific enolase and glial fibrillary acidic protein were elevated acutely and corresponded to the degree of injury, but returned to baseline within 24 h. Serum cytokines interleukin-6 and keratinocyte-derived chemokine were significantly increased within 90 min of TBI. Interleukin-6 levels correlated with the degree of injury.Conclusions
The current study provides a reproducible model of mild TBI in mice that exhibits pathologic features of mild TBI in humans. Furthermore, our data suggest that serum cytokines, such as IL-6, may be effective biomarkers for severity of head injury. 相似文献22.
Keisuke Usui Akira Isobe Naoya Hara Naoto Shikama Keisuke Sasai Koichi Ogawa 《Medical Dosimetry》2019,44(4):344-353
Total body irradiation (TBI) using helical tomotherapy (HT) has advantages over the standard linear accelerator-based approach to the conditioning regimen for hematopoietic cell transplantation. However, the radiation field has to be divided into two independent irradiation plans to deliver a homogeneous dose to the whole body. A clinical target volume near the skin increases the skin surface dose; therefore, high- or low-dose regions arise depending on the set-up position accuracy because the two radiation fields are somewhat overlapped or separated. We aimed to determine an adequate treatment planning method robust to the set-up accuracy for the field joint dose distribution using HT-TBI. We calculated treatment plans reducing target volumes at the interface between the upper and lower body irradiations and evaluated these joint dose distributions via simulation and experimental studies. Target volumes used for the optimization calculation were reduced by 0, 0.5, 1.0, 2.0, 2.5, and 3.0 cm from the boundary surface on the upper and lower sides. Combined dose distributions with set-up error simulated by modifying coordinate positions were investigated to find the optimal planning method. In the ideal set-up position, the target volume without a gap area caused field junctional doses of up to approximately 200%; therefore, target volumes reduced by 2.0–3.0 cm could suppress the maximum dose to within 150%. However, with set-up error, high-dose areas exceeding 150% and low-dose areas below 100% were found with 2.0 and 3.0 cm target volume reduction. Using the dynamic jaw (DJ) system, dose deviations caused by set-up error reached approximately 20%, which is not suitable for HT-TBI. Moreover, these dose distributions can be easily adjusted when combined with the intensity modulation technique for field boundary regions. The results of a simulation and experimental study using a film dosimetry were almost identical, which indicated that reducing the target volume at the field boundary surface by 2.5 cm produces the most appropriate target definition. 相似文献
23.
In vitro models of brain injury that use thick 3-D cultures and control extracellular matrix constituents allow evaluation of cell–matrix
interactions in a more physiologically relevant configuration than traditional 2-D cultures. We have developed a 3-D cell
culture system consisting of primary rat cortical neurons distributed throughout thick (>500 μm) gels consisting of type IV
collagen (Col) conjugated to agarose. Neuronal viability and neurite outgrowth were examined for a range of agarose (AG) percentages
(1.0–3.0%) and initial collagen concentrations ([Col]i; 0–600 μg/mL). In unmodified AG, 1.5% gels supported viable cultures with significant neurite outgrowth, which was not found
at lower (≤1.0%) concentrations. Varying [Col]i in 1.25% AG revealed the formation of dense, 3-D neurite networks at [Col]i of 300 μg/mL, while neurons in unmodified AG and at higher [Col]i (600 μg/mL) exhibited significantly less neurite outgrowth; although, neuronal survival did not vary with [Col]i. The effect of [Col]i on acute neuronal response following high magnitude, high rate shear deformation (0.50 strain, 30 s−1 strain rate) was evaluated in 1.5% AG for [Col]i of 30, 150, and 300 μg/mL, which supported cultures with similar baseline viability and neurite outgrowth. Conjugation of
Col to AG also increased the complex modulus of the hydrogel. Following high rate deformation, neuronal viability significantly
decreased with increasing [Col]i, implicating cell–matrix adhesions in acute mechanotransduction events associated with traumatic loading. These results suggest
interrelated roles for matrix mechanical properties and receptor-mediated cell–matrix interactions in neuronal viability,
neurite outgrowth, and transduction of high rate deformation. This model system may be further exploited for the elucidation
of mechanotransduction mechanisms and cellular pathology following mechanical insult.
D. Kacy Cullen and M. Christian Lessing contributed equally to this work. 相似文献
24.
Aparna Vadlamani Justin A. Perry Maureen McCunn Deborah M. Stein Jennifer S. Albrecht 《Archives of physical medicine and rehabilitation》2019,100(9):1622-1628
ObjectiveTo determine if there were racial differences in discharge location among older adults treated for traumatic brain injury (TBI) at a level 1 trauma center.DesignRetrospective cohort study.SettingR Adams Cowley Shock Trauma Center.ParticipantsBlack and white adults aged ≥65 years treated for TBI between 1998 and 2012 and discharged to home without services or inpatient rehabilitation (N=2902).Main Outcome MeasuresWe assessed the association between race and discharge location via logistic regression. Covariates included age, sex, Abbreviated Injury Scale-Head score, insurance type, Glasgow Coma Scale score, and comorbidities.ResultsThere were 2487 (86%) whites and 415 blacks (14%) in the sample. A total of 1513 (52%) were discharged to inpatient rehabilitation and 1389 (48%) were discharged home without services. In adjusted logistic regression, blacks were more likely to be discharged to inpatient rehabilitation than to home without services compared to whites (odds ratio 1.34, 95% confidence interval, 1.06-1.70).ConclusionsIn this group of Medicare-eligible older adults, blacks were more likely to be discharged to inpatient rehabilitation compared to whites. 相似文献
25.
Wojciech Dabrowski Todd T. Schlegel Jaroslaw Wosko Radoslaw Rola Ziemowit Rzecki Manu L.N.G. Malbrain Andrzej Jaroszynski 《Journal of electrocardiology》2018,51(3):499-507
Introduction
Traumatic brain injury (TBI) affects cardiac electrical function, and several extra-cerebral factors, including intra-abdominal pressure (IAP), might further modulate this brain-heart interaction. The purpose of this study was to investigate the impact of TBI, and of increased IAP during TBI, on cardiac electrical function as measured by vectorcardiographic (VCG) variables.Methods
Survival, IAP and changes in VCG variables including spatial QRS-T angle and QTc interval were measured in consecutive adult patients with either isolated TBI (iTBI), or with TBI accompanied by polytrauma to the abdomen and/or limbs (pTBI). For all patients, observations were performed just after the admission to the ICU (baseline) and at 24, 48, 72 and 96 h after admission.Results
74 patients aged 45 ± 18 were studied. 44 were treated for iTBI and 30 for pTBI. In all patients, spatial QRS-T angle and QTc interval increased after TBI (p < 0.001), relatively more so in patients with pTBI. Compared to survivors, non-survivors also ultimately had greater widening of the spatial QRS-T angle (p < 0.001), most notably just before foraminal herniation. Wider spatial QRS-T angle and longer QTc interval were also noted in patients with IAP > 12 mmHg (p < 0.001), and with right compared to left hemispheric injury (p < 0.001). ST segment level at the J point decreased 24 and 48 h after TBI in leads I, II, III, aVR, aVF, V1, V2, V3 and V6, and increased in lead V1, especially in non-survivors.Conclusions
Spatial QRS-T angle and QTc interval increase after TBI. If foraminal herniation complicates TBI, further widening of the spatial QRS-T angle typically precedes it, followed by notable narrowing thereafter. Increased IAP also intensifies TBI-associated increases in spatial QRS-T angle and QTc interval. 相似文献26.
Tarek H.Mouhieddine Firas H.Kobeissy Muhieddine Itani Amaly Nokkari Kevin K.W.Wang 《中国神经再生研究》2014,9(9):901-906
The prevalence of neurodegenerative diseases and neural injury disorders is increasing worldwide. Research is now focusing on improving current neurogenesis techniques including neural stem cell therapy and other biochemical drug-based approaches to ameliorate these disorders. Unfortunately, we are still facing many obstacles that are rendering current neurotherapies ineffective in clinical trials for reasons that are yet to be discovered. That is why we should start by fully understanding the complex mechanisms of neurogenesis and the factors that affect it, or else, all our suggested therapies would fail since they would not be targeting the essence of the neurological disorder but rather the symptoms. One possible paradigm shift is to switch from neuroprotectant therapies towards neurodegeneration/neurorestorative approaches. In addition, other and our laboratories are increasingly focusing on combining the use of pharmacological agents(such as Rho-associated kinase(ROCK) inhibitors or other growth factors(such as brain-derived neurotrophic factor(BDNF)) and stem cell treatment to enhance the survivability and/or differentiation capacity of transplanted stem cells in neurotrauma or other neurodegeneration animal models. Ongoing stem cell research is surely on the verge of a breakthrough of multiple effective therapeutic options for neurodegenerative disorders. Once, we fully comprehend the process of neurogenesis and its components, we will fully be capable of manipulating and utilizing it. In this work, we discuss the current knowledge of neuroregenerative therapies and their associated challenges. 相似文献
27.
Stian Bahr Sandmo Thor Einar Andersen Inga Katharina Koerte Roald Bahr 《Scandinavian journal of medicine & science in sports》2020,30(1):193-198
Restrictions on heading in youth football have been implemented in some countries to limit head impact exposure. However, current interventions remain poorly guided by evidence. Our objective was to quantify heading exposure in youth football, assessing the effects of sex and age. Football matches played during an international youth football tournament with no heading restrictions were directly observed, including players from both sexes (11-19 years). The elite senior level was included for comparison, using video analysis. All heading events were registered, classified, and assigned to individual players. Heading rates were calculated for each sex and age group. We observed a total of 267 matches, corresponding to 4011 player hours (1927 player hours for females, 2083 player hours for males). Males headed more frequently than females (2.7 vs 1.8 headers/player hour; P < .001). Heading rates increased with age (ANOVA, P < .001), approaching the elite senior level for players 16 years and older. There was substantial variation within teams for all age and sex groups, with the widest range (1-18 headers) observed for girls aged 19. Girls younger than 12 years had the lowest exposure, with an average of <2 players per team heading the ball, each with 1-2 headers. In conclusion, age and sex influence head impact exposure in youth football, and warrants careful consideration when introducing injury prevention measures. Males are more frequently exposed than females, heading rates increase with age, and there is substantial variation between players. Heading is a rare event in the youngest age groups, especially among females. 相似文献
28.
Wei Chen Ping Zheng Tao Hong Yang Wang Ning Liu Bin He Shufeng Zou Dabin Ren Jian Duan Lin Zhao Jiugeng Feng 《Journal of tissue engineering and regenerative medicine》2020,14(3):412-423
Astrocytes are more resistant to ischemia and hypoxia in the acute phase of brain injury after traumatic brain injury (TBI). Previous study showed that gap junction alpha 1 (GJA1) phosphorylation can increase the survival of damaged astrocytes. The GJA1‐20 k expression in neurons co‐culture with astrocytes was positively correlated with exosomes uptake. This study aims to explore the effect of exogenous GJA1‐20 k carried by astrocyte‐derived exosomes on neurons apoptosis and mitochondrial function after TBI. Astrocytes were co‐cultured with the neuron with/without damage from air pressure. Exosomes were isolated, extracted from the culture medium by differential ultra‐centrifugation, and verified by electron microscopy. Immunofluorescence staining, tunnel, western blot were employed to detect exosomes marker CD60, apoptosis, and mitochondrial function related protein expression and GJA1‐20 k in cell culture. A rat model of hydraulic injury TBI was built, and exosomes was transferred. 2,3,5‐Triphenyltetrazolium chloride (TTC) staining and immunohistochemistry staining of Nissl and microtubule associated protein 2 were used to detect the brain damage. A transwell stereo culture model of astrocytes and TBI‐like injured neuron was constructed. The exosomes derived from astrocytes promoted the recovery of damaged neuron by in vitro exosome treatment. Compared with GJA1‐20 k knockout exosome control group, GJA1‐20 k exosomes were uptaken by neuron and downregulated the apoptosis rate and upregulated mitochondrial function to promote neuronal recovery. Finally, the results were validated by TTC staining and damaged tissue sections of rat TBI model. This study contributes to a better understanding of the astrocyte‐neuron protection mechanism in TBI and provides a potential new target for the treatment of TBI. 相似文献
29.
Radia Abdul-Wahab Mathew T. Long Rafael Ordaz Bruce G. Lyeth Bryan J. Pfister 《Journal of neuroscience research》2020,98(10):2027-2044
Millions suffer a traumatic brain injury (TBI) each year wherein the outcomes associated with injury can vary greatly between individuals. This study postulates that variations in each biomechanical parameter of a head trauma lead to differences in histological and behavioral outcome measures that should be considered collectively in assessing injury. While trauma severity typically scales with the magnitude of injury, much less is known about the effects of rate and duration of the mechanical insult. In this study, a newly developed voice-coil fluid percussion injury system was used to investigate the effects of injury rate and fluid percussion impulse on a collection of post-injury outcomes in male rats. Collectively the data suggest a potential shift in the specificity and progression of neuronal injury and function rather than a general scaling of injury severity. While a faster, shorter fluid percussion first presents as a mild TBI, neuronal loss and some behavioral tasks were similar among the slower and faster fluid percussion injuries. This study concludes that the sequelae of neuronal degeneration and behavioral outcomes are related to the complete temporal profile of the fluid percussion and do not scale only with peak pressure. 相似文献
30.
Jihyun Kim Alexandra A. Adams Pradeepa Gokina Brayan Zambrano Jeyanthan Jayakumaran Radek Dobrowolski Patrice Maurel Bryan J. Pfister Haesun A. Kim 《Glia》2020,68(10):2070-2085
Myelin loss in the brain is a common occurrence in traumatic brain injury (TBI) that results from impact-induced acceleration forces to the head. Fast and abrupt head motions, either resulting from violent blows and/or jolts, cause rapid stretching of the brain tissue, and the long axons within the white matter tracts are especially vulnerable to such mechanical strain. Recent studies have shown that mechanotransduction plays an important role in regulating oligodendrocyte progenitors cell differentiation into oligodendrocytes. However, little is known about the impact of mechanical strain on mature oligodendrocytes and the stability of their associated myelin sheaths. We used an in vitro cellular stretch device to address these questions, as well as characterize a mechanotransduction mechanism that mediates oligodendrocyte responses. Mechanical stretch caused a transient and reversible myelin protein loss in oligodendrocytes. Cell death was not observed. Myelin protein loss was accompanied by an increase in intracellular Ca2+ and Erk1/2 activation. Chelating Ca2+ or inhibiting Erk1/2 activation was sufficient to block the stretch-induced loss of myelin protein. Further biochemical analyses revealed that the stretch-induced myelin protein loss was mediated by the release of Ca2+ from the endoplasmic reticulum (ER) and subsequent Ca2+-dependent activation of Erk1/2. Altogether, our findings characterize an Erk1/2-dependent mechanotransduction mechanism in mature oligodendrocytes that de-stabilizes the myelination program. 相似文献