| 1. |
- Aaro Jonsson, Catherine, et al.
(författare)
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Cognitive Recovery and Development after Traumatic Brain Injury in Childhood : A Person-Oriented, Longitudinal Study
- 2013
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 30:2, s. 76-83
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Tidskriftsartikel (refereegranskat)abstract
- Influence of childhood traumatic brain injury (TBI) on cognitive recovery and subsequent development is poorly understood. In this longitudinal study we used cluster analysis to explore acute stage individual profiles of injury age and cognition in 118 children with traumatic brain injury. Repeated measures of cognitive function were conducted at 30 months, indicating recovery, and 10 years post-injury, indicating development. Nine clusters were identified. Recovery was evident in three clusters, two of them with low functioning profiles. Developmental gains occurred for three clusters and an acute profile of higher freedom from distractibility (FFD) and lower processing speed (PS) was related to positive differences. One cluster, average low functioning and especially low verbal comprehension, demonstrated a slower development than peers. This suggests that developmental change after TBI in childhood takes place on a continuum, with both chance of long-term catching up, and risk of poor development. An acute profile of higher FFD and lower PS seemed to reflect injury consequences and were followed by developmental gains. These results challenge previous findings, and warrant further investigation.
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| 2. |
- Brophy, Gretchen M., et al.
(författare)
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Biokinetic analysis of ubiquitin C-terminal hydrolase-L1 (UCH-L1) in severe traumatic brain injury patient biofluids
- 2011
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 28:6, s. 861-870
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Tidskriftsartikel (refereegranskat)abstract
- Ubiquitin C-terminal hydrolase-L1 (UCH-L1) is a neuron-specific enzyme that has been identified as a potential biomarker of traumatic brain injury (TBI). The study objectives were to determine UCH-L1 exposure and kinetic metrics, determine correlations between biofluids, and assess outcome correlations in severe TBI patients. Data were analyzed from a prospective, multicenter study of severe TBI (Glasgow Coma Scale [GCS] score ≤ 8). Cerebrospinal fluid (CSF) and serum data from samples taken every 6 h after injury were analyzed by enzyme-linked immunosorbent assay (ELISA). UCH-L1 CSF and serum data from 59 patients were used to determine biofluid correlations. Serum samples from 86 patients and CSF from 59 patients were used to determine outcome correlations. Exposure and kinetic metrics were evaluated acutely and up to 7 days post-injury and compared to mortality at 3 months. There were significant correlations between UCH-L1 CSF and serum median concentrations (r(s)=0.59, p<0.001), AUC (r(s)=0.3, p=0.027), Tmax (r(s)=0.68, p<0.001), and MRT (r(s)=0.65, p<0.001). Outcome analysis showed significant increases in median serum AUC (2016 versus 265 ng/mL*min, p=0.006), and Cmax (2 versus 0.4 ng/mL, p=0.003), and a shorter Tmax (8 versus 19 h, p=0.04) in those who died versus those who survived, respectively. In the first 24 h after injury, there was a statistically significant acute increase in CSF and serum median Cmax((0-24h)) in those who died. This study shows a significant correlation between UCH-L1 CSF and serum median concentrations and biokinetics in severe TBI patients, and relationships with clinical outcome were detected.
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| 3. |
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| 4. |
- Clausen, Fredrik, et al.
(författare)
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Interstitial F2-Isoprostane 8-Iso-PGF2α As a Biomarker of Oxidative Stress after Severe Human Traumatic Brain Injury
- 2012
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 29:5, s. 766-775
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Tidskriftsartikel (refereegranskat)abstract
- Oxidative stress is a major contributor to the secondary injury process after experimental traumatic brain injury (TBI). The importance of oxidative stress in the pathobiology of human TBI is largely unknown. The F(2)-isoprostane 8-iso-prostaglandin F(2α) (8-iso-PGF(2α)), synthesized in vivo through non-enzymatic free radical catalyzed peroxidation of arachidonic acid, is a widely used biomarker of oxidative stress in multiple disease states, including TBI and cerebral ischemia/reperfusion. Our hypothesis is that harvesting of biomarkers directly in the injured brain by cerebral microdialysis (MD) is advantageous because of its high spatial and temporal resolution compared to blood or cerebrospinal fluid sampling. The aim of this study was to test the feasibility of measuring 8-iso-PGF(2α) in MD, ventricular cerebrospinal fluid (vCSF), and plasma samples collected from patients with severe TBI, and to compare the MD signals with MD-glycerol, implicated as a biomarker of oxidative stress, as well as MD-glutamate, a biomarker of excitotoxicity. Six patients (4 men, 2 women) were included in the study, three of whom had a focal/mixed TBI, and three a diffuse axonal injury (DAI). Following the bedside analysis of routine MD biomarkers (glucose, lactate:pyruvate ratio, glycerol, and glutamate), two 12-h MD samples per day were used to analyze 8-iso-PGF(2α) from 24 h up to 8 days post-injury. The interstitial levels of 8-iso-PGF(2α) were markedly higher than the levels obtained from plasma and vCSF (p<0.05), supporting our hypothesis. The MD-8-iso-PGF(2α) levels correlated strongly (p<0.05) with MD-glycerol and MD-glutamate, which are widely used biomarkers of membrane phospholipid degradation/oxidative stress and excitotoxicity, respectively. This study demonstrates the feasibility of analyzing 8-iso-PGF(2α) in MD samples from the human brain. Our results support a close relationship between oxidative stress and excitotoxicity following human TBI. MD-8-iso-PGF(2α) in combination with MD-glycerol may be useful biomarkers of oxidative stress in the neurointensive care setting.
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| 5. |
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| 6. |
- Czeiter, Endre, et al.
(författare)
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Brain Injury Biomarkers May Improve the Predictive Power of the IMPACT Outcome Calculator
- 2012
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 29:9, s. 1770-1778
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Tidskriftsartikel (refereegranskat)abstract
- Outcome prediction following severe traumatic brain injury (sTBI) is a widely investigated field of research. A major breakthrough is represented by the IMPACT prognostic calculator based on admission data of more than 8500 patients. A growing body of scientific evidence has shown that clinically meaningful biomarkers, including glial fibrillary acidic protein (GFAP), ubiquitin C-terminal hydrolase-L1 (UCH-L1), and alpha II-spectrin breakdown product (SBDP145), could also contribute to outcome prediction. The present study was initiated to assess whether the addition of biomarkers to the IMPACT prognostic calculator could improve its predictive power. Forty-five sTBI patients (GCS score <= 8) from four different sites were investigated. We utilized the core model of the IMPACT calculator (age, GCS motor score, and reaction of pupils), and measured the level of GFAP, UCH-L1, and SBDP145 in serum and cerebrospinal fluid (CSF). The forecast and actual 6-month outcomes were compared by logistic regression analysis. The results of the core model itself, as well as serum values of GFAP and CSF levels of SBDP145, showed a significant correlation with the 6-month mortality using a univariate analysis. In the core model, the Nagelkerke R-2 value was 0.214. With multivariate analysis we were able to increase this predictive power with one additional biomarker (GFAP in CSF) to R-2 = 0.476, while the application of three biomarker levels (GFAP in CSF, GFAP in serum, and SBDP145 in CSF) increased the Nagelkerke R-2 to 0.700. Our preliminary results underline the importance of biomarkers in outcome prediction, and encourage further investigation to expand the predictive power of contemporary outcome calculators and prognostic models in TBI.
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| 7. |
- Ekmark-Lewén, Sara, et al.
(författare)
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The Multivariate Concentric Square Field Test Reveals Behavioral Profiles of Risk Taking, Exploration, and Cognitive Impairment in Mice Subjected to Traumatic Brain Injury
- 2010
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 27:9, s. 1643-1655
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Tidskriftsartikel (refereegranskat)abstract
- There is a need for more efficient tests to evaluate functional outcome following experimental traumatic brain injury (TBI), reflecting deficits in cognitive, sensory, and motor functions that are seen in TBI patients. The Multivariate Concentric Square Field (TM) (MCSF) test is a relatively new behavioral model that measures exploration, risk taking, risk assessment, and shelter seeking, all of which are evolutionarily-conserved strategies for survival. The multivariate design enables scoring of different functional domains in a single test situation, with a free choice of optional environmental settings. Furthermore, repeated trials permits cognitive effects to be measured. In the present study, 11 anesthetized C57BL6 mice received controlled cortical injury (CCI) (0.5mm and 3.3 m/sec) over the right parietal cerebral cortex or sham surgery (n - 12). Naive mice (n 12) not subjected to any surgical procedure were also included. The animals were evaluated in the MCSF test at 2 and 7 days post-surgery, and behavioral profiles were analyzed. The results revealed differences in risk taking and explorative behavior between the sham animals and the animals subjected to trauma. Animals subjected to trauma were characterized by taking more risks and had a higher level of exploration activity, but they sought less shelter. Repeated exposure to the MCSF caused a general decrease in activity in the naive and sham group, while a more specific behavioral impairment was seen in injured mice, suggesting cognitive dysfunction. We submit that the MCSF test is a useful complementary tool for functional outcome evaluation in experimental TBI.
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| 8. |
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| 9. |
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| 10. |
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| 11. |
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| 12. |
- Hanell, Anders, et al.
(författare)
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Functional and Histological Outcome after Focal Traumatic Brain Injury Is Not Improved in Conditional EphA4 Knockout Mice
- 2012
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 29:17, s. 2660-2671
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the role of the axon guidance molecule EphA4 following traumatic brain injury (TBI) in mice. Neutralization of EphA4 improved motor function and axonal regeneration following experimental spinal cord injury (SCI). We hypothesized that genetic absence of EphA4 could improve functional and histological outcome following TBI. Using qRT-PCR in wild-type (WT) mice, we evaluated the EphA4 mRNA levels following controlled cortical impact (CCI) TBI or sham injury and found it to be downregulated in the hippocampus (p < 0.05) but not the cortex ipsilateral to the injury at 24 h post-injury. Next, we evaluated the behavioral and histological outcome following CCI using WT mice and Emx1-Cre-driven conditional knockout (cKO) mice. In cKO mice, EphA4 was completely absent in the hippocampus and markedly reduced in the cortical regions from embryonic day 16, which was confirmed using Western blot analysis. EphA4 cKO mice had similar learning and memory abilities at 3 weeks post-TBI compared to WT controls, although brain-injured animals performed worse than sham-injured controls (p < 0.05). EphA4 cKO mice performed similarly to WT mice in the rotarod and cylinder tests of motor function up to 29 days post-injury. TBI increased cortical and hippocampal astrocytosis (GFAP immunohistochemistry, p < 0.05) and hippocampal sprouting (Timm stain, p < 0.05) and induced a marked loss of hemispheric tissue (p < 0.05). EphA4 cKO did not alter the histological outcome. Although our results may argue against a beneficial role for EphA4 in the recovery process following TBI, further studies including post-injury pharmacological neutralization of EphA4 are needed to define the role for EphA4 following TBI.
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| 13. |
- Hansson, Magnus, et al.
(författare)
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Cyclophilin D-sensitive mitochondrial permeability transition in adult human brain and liver mitochondria.
- 2011
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 1557-9042 .- 0897-7151. ; 28, s. 143-153
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Tidskriftsartikel (refereegranskat)abstract
- The mitochondrial permeability transition (mPT) is considered to be a major cause of cell death under a variety of pathophysiological conditions of the CNS and other organs. Pharmacological inhibition or genetic knock-out of the matrix protein cyclophilin D (CypD) prevents mPT and cell degeneration in several models of brain injury. Provided that findings in animal models can be translatable to human disease, pharmacological inhibition of mPT offers a promising therapeutic target. The objective of this study was to validate the presence of a CypD-sensitive mPT in adult human brain and liver mitochondria. In order to perform functional characterization of human mitochondria, fresh tissue samples were obtained during hemorrhage or tumor surgery and mitochondria were rapidly isolated. Mitochondrial calcium retention capacity, a quantitative assay for mPT, was significantly increased by the CypD inhibitor cyclosporin A in both human brain and liver mitochondria, whereas thiol-reactive compounds and oxidants sensitized mitochondria to calcium-induced mPT. Brain mitochondria underwent swelling upon calcium overload, which was reversible upon calcium removal. To further explore mPT of human mitochondria, liver mitochondria were demonstrated to exhibit several classical features of the mPT phenomenon such as calcium-induced loss of membrane potential and respiratory coupling, as well as release of the pro-apoptotic protein cytochrome c. It is concluded that adult viable human brain and liver mitochondria possess an active CypD-sensitive mPT. The present findings support the rationale of CypD and mPT inhibition as pharmacological targets in acute and chronic neurodegeneration.
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| 14. |
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| 15. |
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| 16. |
- Hussain, Zubair Muhammad, et al.
(författare)
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Lateralized Response of Dynorphin A Peptide Levels after Traumatic Brain Injury
- 2012
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 29:9, s. 1785-1793
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Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury (TBI) induces a cascade of primary and secondary events resulting in impairment of neuronal networks that eventually determines clinical outcome. The dynorphins, endogenous opioid peptides, have been implicated in secondary injury and neurodegeneration in rodent and human brain. To gain insight into the role of dynorphins in the brain's response to trauma, we analyzed short-term (1-day) and long-term (7-day) changes in dynorphin A (Dyn A) levels in the frontal cortex, hippocampus, and striatum, induced by unilateral left-side or right-side cortical TBI in mice. The effects of TBI were significantly different from those of sham surgery (Sham), while the sham surgery also produced noticeable effects. Both sham and TBI induced short-term changes and long-term changes in all three regions. Two types of responses were generally observed. In the hippocampus, Dyn A levels were predominantly altered ipsilateral to the injury. In the striatum and frontal cortex, injury to the right (R) hemisphere affected Dyn A levels to a greater extent than that seen in the left (L) hemisphere. The R-TBI but not L-TBI produced Dyn A changes in the striatum and frontal cortex at 7 days after injury. Effects of the R-side injury were similar in the two hemispheres. In naive animals, Dyn A was symmetrically distributed between the two hemispheres. Thus, trauma may reveal a lateralization in the mechanism mediating the response of Dyn A-expressing neuronal networks in the brain. These networks may differentially mediate effects of left and right brain injury on lateralized brain functions.
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| 17. |
- Hånell, Anders, et al.
(författare)
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Genetic Deletion and Pharmacological Inhibition of Nogo-66 Receptor Impairs Cognitive Outcome after Traumatic Brain Injury in Mice
- 2010
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 27:7, s. 1297-1309
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Tidskriftsartikel (refereegranskat)abstract
- Functional recovery is markedly restricted following traumatic brain injury (TBI), partly due to myelin-associated inhibitors including Nogo-A, myelin-associated glycoprotein (MAG) and oligodendrocyte myelin glycoprotein (OMgp), that all bind to the Nogo-66 receptor-1 (NgR1). In previous studies, pharmacological neutralization of both Nogo-A and MAG improved outcome following TBI in the rat, and neutralization of NgR1 improved outcome following spinal cord injury and stroke in rodent models. However, the behavioral and histological effects of NgR1 inhibition have not previously been evaluated in TBI. We hypothesized that NgR1 negatively influences behavioral recovery following TBI, and evaluated NgR1(-/-) mice (NgR1(-/-) study) and, in a separate study, soluble NgR1 infused intracerebroventricularly immediately post-injury to neutralize NgR1 (sNgR1 study) following TBI in mice using a controlled cortical impact (CCI) injury model. In both studies, motor function, TBI-induced loss of tissue, and hippocampal beta-amyloid immunohistochemistry were not altered up to 5 weeks post-injury. Surprisingly, cognitive function (as evaluated with the Morris water maze at 4 weeks post-injury) was significantly impaired both in NgR1(-/-) mice and in mice treated with soluble NgR1. In the sNgR1 study, we evaluated hippocampal mossy fiber sprouting using the Timm stain and found it to be increased at 5 weeks following TBI. Neutralization of NgR1 significantly increased mossy fiber sprouting in sham-injured animals, but not in brain-injured animals. Our data suggest a complex role for myelin-associated inhibitors in the behavioral recovery process following TBI, and urge caution when inhibiting NgR1 in the early post-injury period.
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| 18. |
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| 19. |
- Krave, Ulrika, 1973, et al.
(författare)
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Rotational Acceleration Closed Head Flexion Trauma Generates More Extensive Diffuse Brain Injury than Extension Trauma
- 2011
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 1557-9042 .- 0897-7151. ; 28:1, s. 57-70
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Tidskriftsartikel (refereegranskat)abstract
- Our aim was to investigate if seemingly identical head and neck trauma would generate differing types of braindamage. We experimentally evaluated induced brain injuries immediately after trauma exposure, and at 1 weekpost-injury. Anesthetized rabbits were exposed once to a sagittal rotational acceleration head and neck injury ateither a high or a low load level, using either flexion or extension. A high-load extension trauma induced scatteredmeningeal petechial hemorrhages and no deaths, in contrast to a flexion trauma of the same level, which resultedin extensive parenchymal and meningeal hemorrhages, and all animals succumbed immediately. A low-levelflexion trauma induced scattered meningeal petechiae, but no gross damage, while extension at the same forcegenerated no macroscopically visible acute brain injury. Immunohistochemical investigations carried out at 7 daysdisclosed that a low-level flexion trauma, as well as both low- and high-level extension exposures, all induceddiffuse brain injuries in the cerebral cortex and white matter, corpus callosum, hippocampus, brainstem, andcerebellum, as revealed by abnormal distribution of neurofilaments, a prevalence of b-amyloid precursor protein,and astrogliosis. The diffuse brain injury seen after a low-level flexion trauma was equal to or more extensive thanthat seen after a high-level extension trauma. A low-level extension trauma induced only minor histopathologicalabnormalities. We conclude that a sagittal rotational acceleration trauma of the head and neck induced diffusebrain injury, and that flexion caused more extensive damage than extension at the same applied load.
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| 20. |
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| 21. |
- Marklund, Niklas, et al.
(författare)
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Monitoring of β-amyloid dynamics after human traumatic brain injury
- 2014
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 1557-9042 .- 0897-7151. ; 31:1, s. 42-55
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Tidskriftsartikel (refereegranskat)abstract
- Epidemiological evidence links severe or repeated traumatic brain injury (TBI) to the development of Alzheimer's disease (AD). Accumulation of amyloid precursor protein (APP) occurs with high frequency after TBI, particularly in injured axons, and APP may be cleaved to amyloid-β (Aβ) peptides playing key pathophysiological roles in AD. We used cerebral microdialysis (MD) to test the hypothesis that interstitial Aβ levels are altered following TBI and are related to the injury type, cerebral energy metabolism, age of the patient, and level of consciousness. In the present report, we evaluated 10 mechanically ventilated patients (7 male, 3 female, ages 18-76 years) with a severe TBI, who had intracranial pressure and MD monitoring. Each MD sample was analyzed for hourly routine energy metabolic biomarkers (MD-lactate, MD-pyruvate, MD-glucose, and MD-lactate/pyruvate ratio), cellular distress biomarkers (MD-glutamate, MD-glycerol), and MD-urea. The remaining MD samples were analyzed for Aβ1-40 (Aβ40; n=765 samples) and Aβ1-42 (Aβ42; n=765 samples) in pooled 2 h fractions up to 14 days post-injury, using the Luminex xMAP technique, allowing detection with high temporal resolution of the key Aβ peptides Aβ40 and Aβ42. Data are presented using medians and 25th and 75th percentiles. Both Aβ40 and Aβ42 were consistently higher in patients with predominately diffuse axonal injury compared with patients with focal TBI at days 1-6 post- injury, Aβ42 being significantly increased at 113-116 h post-injury (p<0.05). The Aβ levels did not correlate with the interstitial energy metabolic situation, age of the patient, or the level of consciousness. These results support that interstitial generation of potentially toxic Aβ species may occur following human TBI, particularly related to axonal injury.
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| 22. |
- Mellergard, Pekka, et al.
(författare)
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The Cerebral Extracellular Release of Glycerol, Glutamate, and FGF2 Is Increased in Older Patients following Severe Traumatic Brain Injury
- 2012
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 29:1, s. 112-118
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Tidskriftsartikel (refereegranskat)abstract
- Old age is associated with a poor recovery from traumatic brain injury (TBI). In a retrospective study we investigated if the biochemical response following TBI is age dependent. Extracellular fluids were continuously sampled by microdialysis in 69 patients admitted to our NSICU following severe TBI. The concentrations of glycerol, glutamate, lactate, pyruvate, and eight different cytokines (IL-1 beta, IL-6, IL-10, IL-8, MIP-1 beta, RANTES, FGF2, and VEGF) were determined by fluorescence multiplex bead technology. Patients in the oldest age group (andgt;= 65 years) had significantly higher microdialysate concentrations of glycerol and glutamate compared to younger patients: the mean microdialysate concentration of glycerol increased from 55.9 mu mol/L (25-44 year) to 252 mu mol/L (andgt;= 65 years; p andlt; 0.0001); similarly glutamate increased from 15.8 mmol/L to 92.2 mmol/L (p andlt; 0.0001). The lactate-pyruvate ratio was also significantly higher in the patients andgt;= 65 years of age (63.9) compared with all the other age groups. The patterns of cytokine responses varied. For some cytokines (IL-1b, IL-10, and IL-8) there were no differences between age groups, while for others (MIP-1b, RANTES, VEGF, and IL-6) some differences were observed, but with no clear correlation with increasing age. For FGF2 the mean microdialysate concentration was 43 pg/mL in patients andgt;= 65 years old, significantly higher compared to all other age groups (p andlt; 0.0001). Increased concentrations of glycerol and glutamate would indicate more extensive damaging processes in the elderly. An increase in concentration of FGF2 could serve a protective function, but could also be related to a dysregulation of the timing in the cellular response in elderly patients.
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| 23. |
- Mondello, Stefania, et al.
(författare)
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Glial Neuronal Ratio : A Novel Index for Differentiating Injury Type in Patients with Severe Traumatic Brain Injury
- 2012
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 29:6, s. 1096-1104
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Tidskriftsartikel (refereegranskat)abstract
- Neurobiochemical marker levels in blood after traumatic brain injury (TBI) may reflect structural changes detected by neuroimaging. This study evaluates whether correlations between neuronal (ubiquitin carboxyterminal hydrolase-L1 [UCH-L1]) and glial (glial fibrillary acidic protein [GFAP]) biomarkers may be used as an indicator for differing intracranial pathologies after brain trauma. In 59 patients with severe TBI (Glasgow Coma Scale [GCS] score <= 8) serum samples were obtained at the time of hospital admission and analyzed for UCH-L1 and GFAP. Glial neuronal ratio (GNR) was evaluated as the ratio between GFAP and UCH-L1 concentrations. A logistic regression analysis was used to identify variables associated with type of injury. GNR had a median of 0.85 and was positively correlated with age (R = 0.45, p = 0.003). Twenty-nine patients presented with diffuse injury and 30 with focal mass lesions as assessed by CT scan at admission and classified according to the Marshall Classification. GNR was significantly higher in the focal mass lesion group compared with the diffuse injury group (1.77 versus 0.48, respectively; p = 0.003). Receiver operating characteristic curve analysis showed that GNR discriminated between types of injury (area under the curve [AUC] = 0.72; p = 0.003). GNR was more accurate earlier (<= 12 h after injury) than later (AUC = 0.80; p = 0.002). Increased GNR was independently associated with type of injury, but not age, gender, GCS score, or mechanism of injury. GNR was significantly higher in patients who died, but was not an independent predictor of death. The data from the present study indicate that GNR provides valuable information about different injury pathways, which may be of diagnostic significance. In addition, GNR may help to identify different pathophysiological mechanisms following different types of brain trauma, with implications for therapeutic interventions.
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| 24. |
- Mondello, Stefania, et al.
(författare)
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αII-spectrin breakdown products (SBDPs) : diagnosis and outcome in severe traumatic brain injury patients
- 2010
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 27:7, s. 1203-1213
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Tidskriftsartikel (refereegranskat)abstract
- In this study we assessed the clinical utility of quantitative assessments of alphaII-spectrin breakdown products (SBDP145 produced by calpain, and SBDP120 produced by caspase-3) in cerebrospinal fluid (CSF) as markers of brain damage and outcome after severe traumatic brain injury (TBI). We analyzed 40 adult patients with severe TBI (Glasgow Coma Scale [GCS] score 6 ng/mL) and SBDP120 levels (>17.55 ng/mL) strongly predicted death (odds ratio 5.9 for SBDP145, and 18.34 for SBDP120). The time course of SBDPs in nonsurvivors also differed from that of survivors. These results suggest that CSF SBDP levels can predict injury severity and mortality after severe TBI, and can be useful complements to clinical assessment.
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| 25. |
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| 26. |
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| 27. |
- Nelson, David W., et al.
(författare)
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Multivariate outcome prediction in traumatic brain injury with focus on laboratory values
- 2012
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 29:17, s. 2613-2624
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Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury (TBI) is a major cause of morbidity and mortality. Identifying factors relevant to outcome can provide a better understanding of TBI pathophysiology, in addition to aiding prognostication. Many common laboratory variables have been related to outcome but may not be independent predictors in a multivariate setting. In this study, 757 patients were identified in the Karolinska TBI database who had retrievable early laboratory variables. These were analyzed towards a dichotomized Glasgow Outcome Scale (GOS) with logistic regression and relevance vector machines, a non-linear machine learning method, univariately and controlled for the known important predictors in TBI outcome: age, Glasgow Coma Score (GCS), pupil response, and computed tomography (CT) score. Accuracy was assessed with Nagelkerke's pseudo R2. Of the 18 investigated laboratory variables, 15 were found significant (p<0.05) towards outcome in univariate analyses. In contrast, when adjusting for other predictors, few remained significant. Creatinine was found an independent predictor of TBI outcome. Glucose, albumin, and osmolarity levels were also identified as predictors, depending on analysis method. A worse outcome related to increasing osmolarity may warrant further study. Importantly, hemoglobin was not found significant when adjusted for post-resuscitation GCS as opposed to an admission GCS, and timing of GCS can thus have a major impact on conclusions. In total, laboratory variables added an additional 1.3-4.4% to pseudo R2.
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| 28. |
- Plantman, S, et al.
(författare)
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Characterization of a Novel Rat Model of Penetrating Traumatic Brain Injury
- 2012
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 1557-9042 .- 0897-7151. ; 29:6, s. 1219-1232
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Tidskriftsartikel (refereegranskat)abstract
- A penetrating traumatic brain injury (pTBI) occurs when an object impacts the head with sufficient force to penetrate the skin, scull and meninges and inflict injury directly to the brain parenchyma. This type of injury has been notoriously difficult to model in small laboratory animals, such as rats or mice. To this end, we have established a novel, non-fatal, model for penetrating brain injury, based on a modified air-rifle that accelerates a pellet, which in turn, impacts a small probe that then causes the injury to the experimental animal’s brain. In the present study, we have focused on the acute phase and characterized the tissue destruction, including the increasing cavity formation, white matter degeneration, hemorrhage, edema and gliosis. We also used a battery of behavioral models to examine the neurological outcome, with the most noteworthy finding being impairment of reference memory function. In conclusion, we have described a number of events taking place after pTBI in our model. We expect this model will prove useful in our efforts to unravel the biological events underlying injury and regeneration after pTBI and possibly serve as a useful animal model in development of novel therapeutic and diagnostic approaches.
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| 29. |
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| 30. |
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| 31. |
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| 32. |
- Säljö, Annette, et al.
(författare)
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Low-level blast raises intracranial pressure and impairs cognitive function in rats: prophylaxis with processed cereal feed
- 2010
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 27:2, s. 383-389
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Tidskriftsartikel (refereegranskat)abstract
- There is increasing evidence that even low levels of blast cause brain injury, but little is known about their thresholds and mechanisms. Exposure of rats to 10-60 kPa blasts elevate intracranial pressure (ICP) in a dose-dependent manner and impair cognitive function. We have evaluated a prophylactic measure against these brain injuries in a rat animal model, consisting of feeding them processed cereal. This type of feed is known to ameliorate disturbances in secretion of body fluids and to have anti-inflammatory effects. In humans, intake of processed cereals is effective against intestinal diarrhea and also reduces the symptoms of Ménière's disease. Rats were given either standard laboratory feed or processed cereal feed for 2 weeks before exposure to blast in a shock tube. The ICP was monitored at different time points up to 1 week after exposure to a 60-kPa blast, and for up to 24 h after exposure to a 30-kPa blast. Maximal ICP elevation was reached at 10 h in both groups. In the group of rats on standard feed exposed to 60 kPa, an ICP increase of 145% was noted at 10 h, and the corresponding increase in the rats fed processed cereal feed was only 50%. In rats exposed to a 30-kPa blast, those fed standard feed and processed cereal feed demonstrated increases of ICP of 80% and 40%, respectively. Cognitive function as measured by the Morris water maze was assessed in other groups of rats at 2 days after exposure to 10- or 30-kPa blasts. Their performance was significantly impaired at both exposure levels in rats on standard feed, but no functional impairment was seen in rats fed processed cereal feed.
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| 33. |
- Thelin, Eric Peter, et al.
(författare)
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S100B Is an Important Outcome Predictor in Traumatic Brain Injury
- 2013
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 30:7, s. 519-528
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to examine how S100B, a biomarker of traumatic brain injury (TBI), contributes to outcome prediction after adjusting for known parameters, including age, Glasgow Coma Scale (GCS), pupil reaction, and computed tomography (CT) variables; to examine which parameters have the best correlation to elevated serum levels of S100B; and to investigate when to sample S100B to achieve the strongest association to outcome. This retrospective study included 265 patients with TBI admitted to the neurointensive care unit, Karolinska University Hospital Solna, Stockholm, Sweden. Univariate and multivariate proportional odds regressions were performed to determine parameters most closely related to outcome, and how S100B adds to prediction accuracy. Age (p < 0.0001), pupil reaction (p < 0.0001), and levels of S100B (p < 0.0001) had the strongest statistical correlation to outcome. The area under curve of S100B, the first 48 h after trauma, yielded an additional explained variance of 6.6% in excess of known outcome parameters, including age, GCS, pupil reaction, and CT variables, themselves exhibiting an explained variance of 29.3%. S100B adds substantial information regarding patient outcome, in excess of that provided by known parameters. Only CT variables were found to be significant predictors of increased levels of S100B in uni- and multivariate analysis. Early samples of S100B, within 12 h after trauma, appear to have little prognostic value, and S100B should likely be sampled 12-36 h following trauma to best enhance TBI outcome prediction.
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| 34. |
- Thelin, Eric, et al.
(författare)
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THE SENSITIVITY AND ROLE OF PROTEIN S100B IN DETECTING SECONDARY INJURIES AFTER TRAUMATIC BRAIN INJURY IN HUMANS
- 2011
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 28:6, s. a55-A55
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Patients suffering from traumatic brain injury (TBI) are often treated in specialized neuro-intensive care units (NICU) using multi-modal monitoring to detect harmful secondary insults such as increased intra cranial pressure. In addition to different monitoring devices. serum biomarkers have been shown to provide additional important information regarding the patient. Elevated serum levels of S100B have been detected following TBI. cerebral ischemia. spontaneous intra-cerebral hematomas and edema formation. S100B is known to correlate to outcome. Severe secondary cerebral injuries have been shown to correlate to secondary peaks in serum levels of S100B. Increases of more than 0.1mug/L are considered pathological. METHOD: 267 patients treated in the NICU for TBI with S100B samples obtained every 12 hours during a minimum of a 96-hour time period were included. Secondary increases of S100B after 48 hours following trauma were noted. All patients had at least 2 CT-scans and/or MRI scans performed. RESULTS: 67 secondary injuries during the NICU stay were detected using MRI or CT-scans. The most common lesions were diffuse is- chemic injuries (29). edema (13). cerebral infarctions (11) and intracerebral hematoma (5). Looking at secondary peaks of S100B in detecting radiological verifiable cerebral lesions during the NICU stay. a cut-off level of more than 0.5mug/L the specificity was 100% and sensitivity 8.9%. Decreasing the cut-off level to 0.1mug/L a specificity of 95.9% and sensitivity of 64.2% was obtained. while a cut-off level of 0.05mug/L presented a specificity of 92.7% and sensitivity of 92.5%. CONCLUSIONS: S100B is a sensitive marker for secondary cerebral injuries occurring in the NICU after TBI. A low cut-off point for the secondary peak of S100B (0.05 mug/L) increases sensitivity without any major deficit of specificity in detecting secondary injuries during the NICU stay.
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| 35. |
- Thelin, Eric, et al.
(författare)
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The temporal profiles in serum concentrations of the biomarker S100B in the first 48 hours after traumatic brain injury correspond to outcome
- 2011
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 28:5, s. A20-A20
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Tidskriftsartikel (refereegranskat)abstract
- Background: Traumatic brain injury (TBI) is one of the leading causes of death and disability. An early and accurate assessment of the affected patient suffering from TBI is important to promptly decide upon treatment strategies. Serum levels of the protein S100B are elevated in patients suffering from TBI, and has been proposed as a good addition to other clinical variables when calculating outcome. Different temporal patterns of the serum levels of S100B have been shown. The aim of this study was to analyze the different patterns, with a focus on outcome and other factors related to co-morbidity in patients suffering from TBI.Methods: In all, 265 patients suffering from TBI admitted to the neuro-intensive care unit, having three consecutive serum samples of S100B within the first 72 h after trauma were included.Results: S100B AUC, S100 peak serum level, and increasing serum levels of S100B significantly presence of traumatic subarachnoid hemorrhage, early cerebral ischemia and signs of increasing intracranial hematomas are statistically significant (p<0.05) to high and increasing levels of S100B. Using a multi-nomial logit regression analysis, increased age (p<0.01), early cerebral ischemia (p<0.05), and increased S100B AUC statistically significantly affected mortality (p<0.01).Conclusion: The temporal profile of S100B is unique for every patient after TBI, and statistically correlates with S100B AUC, one of the factors that correlates strongly with mortality and morbidity, and thereby may promptly provide the physician with an important tool in clinical decision-making.
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| 36. |
- Toth, Arnold, et al.
(författare)
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Multi-modal magnetic resonance imaging in the acute and sub-acute phase of mild traumatic brain injury : can we see the difference?
- 2013
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 30:1, s. 2-10
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Tidskriftsartikel (refereegranskat)abstract
- Advanced magnetic resonance imaging (MRI) methods were shown to be able to detect the subtle structural consequences of mild traumatic brain injury (mTBI). The objective of this study was to investigate the acute structural alterations and recovery after mTBI, using diffusion tensor imaging (DTI) to reveal axonal pathology, volumetric analysis, and susceptibility weighted imaging (SWI) to detect microhemorrhage. Fourteen patients with mTBI who had computed tomography with negative results underwent MRI within 3 days and 1 month after injury. High resolution T1-weighted imaging, DTI, and SWI, were performed at both time points. A control group of 14 matched volunteers were also examined following the same imaging protocol and time interval. Tract-Based Spatial Statistics (TBSS) were performed on DTI data to reveal group differences. T1-weighted images were fed into Freesurfer volumetric analysis. TBSS showed fractional anisotropy (FA) to be significantly (corrected p<0.05) lower, and mean diffusivity (MD) to be higher in the mTBI group in several white matter tracts (FA=40,737; MD=39,078 voxels) compared with controls at 72 hours after injury and still 1month later for FA. Longitudinal analysis revealed significant change (i.e., normalization) of FA and MD over 1 month dominantly in the left hemisphere (FA=3408; MD=7450 voxels). A significant (p<0.05) decrease in cortical volumes (mean 1%) and increase in ventricular volumes (mean 3.4%) appeared at 1 month after injury in the mTBI group. SWI did not reveal microhemorrhage in our patients. Our findings present dynamic micro- and macrostructural changes occurring in the acute to sub-acute phase in mTBI, in very mildly injured patients lacking microhemorrhage detectable by SWI. These results underscore the importance of strictly defined image acquisition time points when performing MRI studies on patients with mTBI.
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| 37. |
- Ulfarsson, Trandur, 1967, et al.
(författare)
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Pituitary Function and Functional Outcome in Adults after Severe Traumatic Brain Injury: The Long-Term Perspective.
- 2013
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Ingår i: Journal of neurotrauma. - : Mary Ann Liebert Inc. - 1557-9042 .- 0897-7151. ; 30:4, s. 271-280
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Tidskriftsartikel (refereegranskat)abstract
- Posttraumatic hypopituitarism (PTHP) has been linked to disability and decreased quality of life. However, no studies have addressed the long-term consequences of PTHP in adults with severe traumatic brain injury (TBI) only. In this study, we evaluated the relationship between pituitary function, quality of life, and functioning in 51 patients (age 16-65 years) with severe TBI who were admitted to Sahlgrenska University Hospital, Gothenburg from 1999 to 2002. The patients were assessed once, 2-10 years after trauma. Data from the time of injury were collected retrospectively to adjust for injury severity. Outcome measures included hormonal testing, the Short Form-36 Health Survey, the Glasgow Outcome Scale-Extended, and a self-report questionnaire specifically designed for this study and based on the International Classification of Functioning, Disability and Health. Of 51 patients, 14 (27.5%) presented with PTHP, and 11 (21.6%) had isolated growth hormone deficiency. Patients with PTHP were more often overweight at follow-up (p = 0.01); the higher body mass index was partially explained by PTHP (R2 change = 0.07, p = 0.001). Otherwise no significant correlation was found between PTHP, functioning, or patient-reported quality of life. This study-which is unique in the homogeneity of the patients, the long follow-up time, and the use of injury severity as an outcome predictor-did not confirm results from previous studies linking PTHP to a worse outcome. Thus, screening for PTHP might be restricted to specific subgroups such as overweight patients, indicating growth hormone deficiency.
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| 38. |
- von Holst, Hans, et al.
(författare)
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Numerical Impact Simulation of Gradually Increased Kinetic Energy Transfer Has the Potential To Break Up Folded Protein Structures Resulting in Cytotoxic Brain Tissue Edema
- 2013
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 30:13, s. 1192-1199
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Tidskriftsartikel (refereegranskat)abstract
- Although the consequences of traumatic brain injury (TBI) and its treatment have been improved, there is still a substantial lack of understanding the mechanisms. Numerical simulation of the impact can throw further lights on site and mechanism of action. A finite element model of the human head and brain tissue was used to simulate TBI. The consequences of gradually increased kinetic energy transfer was analyzed by evaluating the impact intracranial pressure (ICP), strain level, and their potential influences on binding forces in folded protein structures. The gradually increased kinetic energy was found to have the potential to break apart bonds of Van der Waals in all impacts and hydrogen bonds at simulated impacts from 6 m/s and higher, thereby superseding the energy in folded protein structures. Further, impacts below 6 m/s showed none or very slight increase in impact ICP and strain levels, whereas impacts of 6 m/s or higher showed a gradual increase of the impact ICP and strain levels reaching over 1000 KPa and over 30%, respectively. The present simulation study shows that the free kinetic energy transfer, impact ICP, and strain levels all have the potential to initiate cytotoxic brain tissue edema by unfolding protein structures. The definition of mild, moderate, and severe TBI should thus be looked upon as the same condition and separated only by a gradual severity of impact.
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| 39. |
- Yaka, Cane, et al.
(författare)
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A novel in vitro injury model based on microcontact printing demonstrates negative effects of hydrogen peroxide on axonal regeneration both in absence and presence of glia
- 2013
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 30:5, s. 392-402
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Tidskriftsartikel (refereegranskat)abstract
- The molecular processes involved in axonal regeneration after traumatic brain injury (TBI) are still not fully understood. In this study, we have established a novel in vitro injury model of TBI based on microcontact printing (μCP) that enables close-up investigations of injured neurons. The model is also suitable for quantitative measurements of axonal outgrowth, making it a useful tool in the studies of basic mechanisms behind axonal regeneration. Cortical neurons from mouse embryos are cultured on μCP cover-slips for 8 days, and the neurons are then injured in a precise manner using a thin plastic tip that does not affect the μCP pattern of extracellular matrix proteins. By close-up time-lapse experiments and immunostainings, we show that the neurons have a tremendous capacity to regenerate their neurites after injury. The cut induces growth cone formation, and the regenerating axons strictly follow the μCP pattern. Moreover, by using the injury model, we demonstrate that hydrogen peroxide (H2O2) decreases axonal regeneration after injury without affecting the neurons' ability to form growth cones. Co-culture with glial cells does not rescue the axonal regeneration, indicating that the mechanism by which H2O2 affects axonal regeneration differ from its cytotoxic effect.
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| 40. |
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| 41. |
- Baumgartner, D., et al.
(författare)
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INFLUENCE OF HEAD ROTATIONAL ACCELERATION PULSE SHAPE ON BRAIN TISSUE STRAINS
- 2014
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Ingår i: Journal of Neurotrauma. - 0897-7151. ; 31:12
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Brain tolerance to rotational acceleration is relevant for understanding injury thresholds and development of injury mitigation techniques for automobiles and sporting events. This computational-modeling study outlined effects of head rotational acceleration pulse shape on strains within brain tissues. A detailed finite element model of the human skull and brain was developed and validated previously. The model was exercised using realistic rotational accelerations with different magnitude and duration characteristics, and the principal strain re- sponse was extracted for parietal cortex, hippocampus, thalamus, and hypothalamus. Rotational acceleration magnitude was varied to three levels: 3.6krad/s 2 (M1), 5.3krad/s 2 (M2), and 6.6krad/s 2 (M3). Duration was varied to 9msec (D1), 18msec (D2), and 27msec (D3). Hippocampus and hypothalamus sustained more strain than cortex and thalamus. With increasing acceleration magnitude from M1 to M2 and M2 to M3, strain in all brain regions was uniformly increased by 42% and 80%. However, strains demonstrated regionally dependent chan- ges with increasing duration (D1 to D3): 68%, 37%, 33% and 14% in parietal cortex, hippocampus, thalamus and hypothalamus, respec- tively. The trend was consistent for all acceleration magnitudes. This study demonstrated differing and independent effects of rotational acceleration magnitude and duration on strains within brain tissues during rotational acceleration. Magnitude has long been a correlate of injury severity and this study supports that finding in that increased acceleration magnitudes led to uniformly higher brain tissue strains (higher injury risk). However, rotational acceleration duration chan- ged the strain distribution within the brain, resulting in different injury risks in different brain regions. This finding is significant as changing strain distribution with different durations can manifest as different injury distributions within the brain and different neuropsychological outcomes following exposure to head rotational acceleration.
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| 42. |
- Bellander, BM
(författare)
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BIOMARKERS OF MILD TBI
- 2014
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Ingår i: JOURNAL OF NEUROTRAUMA. - 0897-7151. ; 31:5, s. A24-A24
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 43. |
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| 44. |
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| 45. |
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| 46. |
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| 47. |
- Kawa, L
(författare)
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MILD BLAST TBI: A SILENT CRIMINAL
- 2013
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Ingår i: JOURNAL OF NEUROTRAUMA. - 0897-7151. ; 30:15, s. A44-A44
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 48. |
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| 49. |
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