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  • 1.
    Abu Hamdeh, Sami
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Rollman Waara, Erik
    BioArctic Neurosci AB, Stockholm, Sweden.
    Möller, Christer
    BioArctic Neurosci AB, Stockholm, Sweden.
    Söderberg, Linda
    BioArctic Neurosci AB, Stockholm, Sweden.
    Basun, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. BioArctic Neuroscience AB, Stockholm, Sweden.
    Alafuzoff, Irina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical and experimental pathology.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics. BioArctic Neuroscience AB, Stockholm, Sweden.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Rapid amyloid-β oligomer and protofibril accumulation in traumatic brain injury2018In: Brain Pathology, ISSN 1015-6305, E-ISSN 1750-3639, Vol. 28, no 4, p. 451-462Article in journal (Refereed)
    Abstract [en]

    Deposition of amyloid-β (Aβ) is central to Alzheimer's disease (AD) pathogenesis and associated with progressive neurodegeneration in traumatic brain injury (TBI). We analyzed predisposing factors for Aβ deposition including monomeric Aβ40, Aβ42 and Aβ oligomers/protofibrils, Aβ species with pronounced neurotoxic properties, following human TBI. Highly selective ELISAs were used to analyze N-terminally intact and truncated Aβ40 and Aβ42, as well as Aβ oligomers/protofibrils, in human brain tissue, surgically resected from severe TBI patients (n = 12; mean age 49.5 ± 19 years) due to life-threatening brain swelling/hemorrhage within one week post-injury. The TBI tissues were compared to post-mortem AD brains (n = 5), to post-mortem tissue of neurologically intact (NI) subjects (n = 4) and to cortical biopsies obtained at surgery for idiopathic normal pressure hydrocephalus patients (iNPH; n = 4). The levels of Aβ40 and Aβ42 were not elevated by TBI. The levels of Aβ oligomers/protofibrils in TBI were similar to those in the significantly older AD patients and increased compared to NI and iNPH controls (P < 0.05). Moreover, TBI patients carrying the AD risk genotype Apolipoprotein E epsilon3/4 (APOE ε3/4; n = 4) had increased levels of Aβ oligomers/protofibrils (P < 0.05) and of both N-terminally intact and truncated Aβ42 (P < 0.05) compared to APOE ε3/4-negative TBI patients (n = 8). Neuropathological analysis showed insoluble Aβ aggregates (commonly referred to as Aβ plaques) in three TBI patients, all of whom were APOE ε3/4 carriers. We conclude that soluble intermediary Aβ aggregates form rapidly after TBI, especially among APOE ε3/4 carriers. Further research is needed to determine whether these aggregates aggravate the clinical short- and long-term outcome in TBI.

  • 2.
    Clausen, Fredrik
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Dahlin, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Chu, Jiangtao
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Kaller, Bodil
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    During, Erik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Novel Microdialysis Method to Study The Acute Cytokine Response to Diffuse Traumatic Brain Injury in the Rat2014In: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 31, no 5, p. A19-A19Article in journal (Refereed)
  • 3.
    Clausen, Fredrik
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hånell, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Björk, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Mir, Anis K.
    Gram, Hermann
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Neutralization of interleukin-1β modifies the inflammatory response and improves histological and cognitive outcome following traumatic brain injury in mice2009In: European Journal of Neuroscience, ISSN 0953-816X, E-ISSN 1460-9568, Vol. 30, no 3, p. 385-396Article in journal (Refereed)
    Abstract [en]

    Interleukin-1beta (IL-1beta) may play a central role in the inflammatory response following traumatic brain injury (TBI). We subjected 91 mice to controlled cortical impact (CCI) brain injury or sham injury. Beginning 5 min post-injury, the IL-1beta neutralizing antibody IgG2a/k (1.5 microg/mL) or control antibody was infused at a rate of 0.25 microL/h into the contralateral ventricle for up to 14 days using osmotic minipumps. Neutrophil and T-cell infiltration and microglial activation was evaluated at days 1-7 post-injury. Cognition was assessed using Morris water maze, and motor function using rotarod and cylinder tests. Lesion volume and hemispheric tissue loss were evaluated at 18 days post-injury. Using this treatment strategy, cortical and hippocampal tissue levels of IgG2a/k reached 50 ng/mL, sufficient to effectively inhibit IL-1betain vitro. IL-1beta neutralization attenuated the CCI-induced cortical and hippocampal microglial activation (P < 0.05 at post-injury days 3 and 7), and cortical infiltration of neutrophils (P < 0.05 at post-injury day 7). There was only a minimal cortical infiltration of activated T-cells, attenuated by IL-1beta neutralization (P < 0.05 at post-injury day 7). CCI induced a significant deficit in neurological motor and cognitive function, and caused a loss of hemispheric tissue (P < 0.05). In brain-injured animals, IL-1beta neutralizing treatment resulted in reduced lesion volume, hemispheric tissue loss and attenuated cognitive deficits (P < 0.05) without influencing neurological motor function. Our results indicate that IL-1beta is a central component in the post-injury inflammatory response that, in view of the observed positive neuroprotective and cognitive effects, may be a suitable pharmacological target for the treatment of TBI.

  • 4.
    Clausen, Fredrik
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Neuroscience. Neurokirurgi.
    Lundqvist, Hanna
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Neuroscience. Neurokirurgi.
    Ekmark, Sara
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Neuroscience. Neurokirurgi.
    Lewen, Anders
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Neuroscience. Neurokirurgi.
    Ebendal, Ted
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Neuroscience. Medicinskt utvecklingsbiologi.
    Hillered, Lars
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Neuroscience. Neurokirurgi.
    Oxygen free radical-dependent activation of extracellular signal-regulated kinase mediates apoptosis-like cell death after traumatic brain injury2004In: Journal of Neurotrauma, Vol. 21, no 9, p. 1168-1182Article in journal (Refereed)
    Abstract [en]

    Mitogen-activated protein kinase (MAPK) cascades are membrane-to-nucleus signaling modules that recently have been implicated as mediators of cellular injury. In this study, we investigated the involvement of the MAP kinase p44/p42 (extracellular signal-regulated kinase [ERK1/2]) in traumatic brain injury (TBI) in rats. There was a strong increase in activated, phosphorylated ERK 1/2 (p-ERK 1/2) protein at 10 min up to 24 h after the injury. Expression of p-ERK occurred in cells identified as neurons, astrocytes, and microglia. Most of the cells expressing p-ERK were TUNEL positive at later time points. Treatment with the MEK inhibitor U0126 or the free radical scavenger S-PBN, both with neuroprotective properties in TBI, attenuated the early activation of ERK and resulted in less activation of caspase-3 and subsequent DNA fragmentation. Post-treatment with U0126 resulted in a significant decrease (-60%) in cortical cavity size and cortical atrophy at 2 weeks after trauma. Overall, the results suggest that ERK activation is initiated by increased oxygen radical activity and that overactivation of ERK sets off secondary cell death mechanisms in TBI. Clinical studies are warranted to evaluate the concept of MEK inhibition in head-injured patients.

  • 5.
    Clausen, Fredrik
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Acute Inflammatory Biomarker Responses to Diffuse Traumatic Brain Injury in the Rat Monitored by a Novel Microdialysis Technique2019In: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 36, no 2, p. 201-211Article in journal (Refereed)
    Abstract [en]

    Neuroinflammation is a major contributor to the progressive brain injury process induced by traumatic brain injury (TBI), and may play an important role in the pathophysiology of axonal injury. The immediate neuroinflammatory cascade cannot be characterized in the human setting. Therefore, we used the midline fluid percussion injury model of diffuse TBI in rats and a novel microdialysis (MD) method providing stable diffusion-driven biomarker sampling. Immediately post-injury, bilateral amphiphilic tri-block polymer coated MD probes (100 kDa cut off membrane) were inserted and perfused with Dextran 500 kDa-supplemented artificial cerebrospinal fluid (CSF) to optimize protein capture. Six hourly samples were analyzed for 27 inflammatory biomarkers (9 chemokines, 13 cytokines, and 5 growth factors) using a commercial multiplex biomarker kit. TBI (n = 6) resulted in a significant increase compared with sham-injured controls (n = 6) for five chemokines (eotaxin/CCL11, fractalkine/CX3CL1, LIX/CXCL5, monocyte chemoattractant protein [MCP]1α/CCL2, macrophage inflammatory protein [MIP]1α /CCL3), 10 cytokines (interleukin [IL]-1α, IL-1β, IL-4, IL-6, IL-10, IL-13, IL-17α, IL-18, interferon [IFN]-γ, tumor necrosis factor [TNF]-α), and four growth factors (epidermal growth factor [EGF], granulocyte-macrophage colony-stimulating factor [GM-CSF], leptin, vascular endothelial growth factor [VEGF]). Therefore, diffuse TBI was associated with an increased level of 18 of the 27 inflammatory biomarkers at one through six time points, during the observation period whereas the remaining 9 biomarkers were unaltered. The study shows that diffuse TBI induces an acute increase in a number of inflammatory biomarkers. The novel MD technique provides stable MD sampling suitable for further studies on the early neuroinflammatory cascade in TBI.

  • 6.
    Clausen, Fredrik
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Basu, Samar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Oxidative Stress and Inflammation.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Interstitial F2-Isoprostane 8-Iso-PGF As a Biomarker of Oxidative Stress after Severe Human Traumatic Brain Injury2012In: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 29, no 5, p. 766-775Article in journal (Refereed)
    Abstract [en]

    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.

  • 7.
    Clausen, Fredrik
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    The nitrone free radical scavenger NXY-059 is neuroprotective when administered after traumatic brain injury in the rat2008In: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 25, no 12, p. 1449-1457Article in journal (Refereed)
    Abstract [en]

    Reactive oxygen species (ROS) are important contributors to the secondary injury cascade following traumatic brain injury (TBI), and ROS inhibition has consistently been shown to be neuroprotective following experimental TBI. NXY-059, a nitrone free radical trapping compound, has been shown to be neuroprotective in models of ischemic stroke but has not been evaluated in experimental TBI. In the present study, a continuous 24-h intravenous infusion of NXY-059 or vehicle was initiated 30min following a severe lateral fluid percussion brain injury (FPI) in adult rats (n=22), and histological and behavioral outcomes were evaluated. Sham-injured animals (n=22) receiving identical drug infusion were used as controls. Visuospatial learning was evaluated in the Morris water maze at post-injury days 11–14, followed by a probe trial (memory test) at day 18. The animals were sacrificed at day 18, and loss of hemispheric brain tissue was measured in microtubule-associated protein (MAP)–2stained sections. Brain-injured, NXY-059-treated animals showed a significant reduction of visuospatial learning deficits when compared to the brain-injured, vehicle-treated control animals (p<0.05). NXY-059-treated animals significantly reduced the loss of hemispheric tissue compared to brain-injured controls (43.0±11mm3 versus 74.4±19mm3, respectively; p<0.01). The results show that post-injury treatment with NXY-059 significantly attenuated the loss of injured brain tissue and improved cognitive outcome, suggesting a major role for ROS in the pathophysiology of TBI.

  • 8.
    Dahlin, Andreas P
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Sjödin, Marcus O D
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Wetterhall, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Quantification of Proteins Adsorbed to Surface Modified and Non-Modified Microdialysis Membranes using on-Surface Enzymatic Digestion (oSED) iTRAQ-MALDI-TOF/TOF MS2012In: 60th ASMS Conference on Mass Spectrometry and Allied Topics, May 20 - 24, Vancouver, Canada, 2012Conference paper (Refereed)
  • 9.
    Dahlin, Andreas P
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Sjödin, Marcus O.D.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Wetterhall, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Multiplexed quantification of proteins adsorbed to surface-modified and non-modified microdialysis membranes2012In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 402, no 6, p. 2057-2067Article in journal (Refereed)
    Abstract [en]

    A simple and straightforward method for discovery and quantification of proteins adsorbed onto delicate and sensitive membrane surfaces is presented. The adsorbed proteins were enzymatically cleaved while still adsorbed onto the membranes using an on-surface enzymatic digestion (oSED). This was followed by isobaric tagging, nanoliquid chromatography, and tandem mass spectrometry. Protein adsorption on tri-block copolymer Poloxamer 407 surface-modified microdialysis (MD) membranes were compared with protein adsorption on unmodified MD membranes. Ventricular cerebrospinal fluid (vCSF) kept at 37 °C was used as sample matrix. In total, 19 proteins were quantified in two biological replicates. The surface-modified membranes adsorbed 33% less proteins than control membranes and the most abundant proteins were subunits of hemoglobin and clusterin. The adsorption of clusterin on the modified membranes was on average 36% compared to control membranes. The most common protein in vCSF, Albumin, was not identified adsorbed to the surface at all. It was also experimentally verified that oSED, in conjunction with tandem mass spectrometry can be used to quantify femtomole amounts of proteins adsorbed on limited and delicate surfaces, such as MD membranes. The method has great potential and can be used to study much more complex protein adsorption systems than previously reported.

  • 10.
    Dahlin, Andreas P
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Purins, Karlis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Clausen, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Chu, Jiangtao
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Sedigh, Amir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Transplantation Surgery.
    Lorant, Tomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Transplantation Surgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Refined microdialysis method for protein biomarker sampling in acute brain injury in the neurointensive care setting2014In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 86, no 17, p. 8671-8679Article in journal (Refereed)
    Abstract [en]

    There is growing interest in cerebral microdialysis (MD) for sampling of protein biomarkers in neurointensive care (NIC) patients. Published data point to inherent problems with this methodology including protein interaction and biofouling leading to unstable catheter performance. This study tested the in vivo performance of a refined MD method including catheter surface modification, for protein biomarker sampling in a clinically relevant porcine brain injury model. Seven pigs of both sexes (10-12 weeks old; 22.2-27.3 kg) were included. Mean arterial blood pressure, heart rate, intracranial pressure (ICP) and cerebral perfusion pressure was recorded during the stepwise elevation of intracranial pressure by inflation of an epidural balloon catheter with saline (1 mL/20 min) until brain death. One naïve MD catheter and one surface modified with Pluronic F-127 (10 mm membrane, 100 kDa molecular weight cutoff MD catheter) were inserted into the right frontal cortex and perfused with mock CSF with 3% Dextran 500 at a flow rate of 1.0 μL/min and 20 min sample collection. Naïve catheters showed unstable fluid recovery, sensitive to ICP changes, which was significantly stabilized by surface modification. Three of seven naïve catheters failed to deliver a stable fluid recovery. MD levels of glucose, lactate, pyruvate, glutamate, glycerol and urea measured enzymatically showed an expected gradual ischemic and cellular distress response to the intervention without differences between naïve and surface modified catheters. The 17 most common proteins quantified by iTRAQ and nanoflow LC-MS/MS were used as biomarker models. These proteins showed a significantly more homogeneous response to the ICP intervention in surface modified compared to naïve MD catheters with improved extraction efficiency for most of the proteins. The refined MD method appears to improve the accuracy and precision of protein biomarker sampling in the NIC setting.

  • 11.
    Dahlin, Andreas P
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Purins, Karlis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewen, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Improved Microdialysis Sampling of Proteins using Surface Modified Catheters: An in vivo Study in Standardized Pig Brain Death Model2013Conference paper (Refereed)
  • 12.
    Dahlin, Andreas P.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Wetterhall, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    Caldwell, Karin D.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    Larsson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Chemistry.
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Methodological aspects on microdialysis protein sampling and quantification in biological fluids: an in vitro study on human ventricular CSF.2010In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 82, no 11, p. 4376-4385Article in journal (Refereed)
    Abstract [en]

    There is growing interest in sampling of protein biomarkers from the interstitial compartment of the brain and other organs using high molecular cutoff membrane microdialysis (MD) catheters. However, recent data suggest that protein sampling across such MD membranes is a highly complex process that needs to be further studied. Here, we report three major improvements for microdialysis sampling of proteins in complex biological matrixes. The improvements in this in vitro study using human ventricular cerebrospinal fluid as the sample matrix include increased fluid recovery control, decreased protein adsorption on the microdialysis membrane and materials, and novel quantitative mass spectrometry analysis. Dextrans in different concentrations and sizes were added to the perfusion fluid. It was found that dextrans with molecular mass 250 and 500 kDa provided a fluid recovery close to 100%. An improved fluid recovery precision could be obtained by self-assembly triblock polymer surface modification of the MD catheters. The modified catheters also delivered a significantly increased extraction efficiency for some of the investigated proteins. The final improvement was to analyze the dialysates with isobaric tagged (iTRAQ) proteomics, followed by tandem mass spectrometric analysis. By using this technique, 48 proteins could be quantified and analyzed with respect to their extraction efficiencies. The novel aspects of microdialysis protein sampling, detection, and quantification in biological fluids presented in this study should be considered as a first step toward better understanding and handling of the challenges associated with microdialysis sampling of proteins. The next step is to optimize the developed methodology in vivo.

  • 13.
    Dyhrfort, Philip
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Shen, Qiujin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Molecular tools.
    Clausen, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. Uppsala Univ, Dept Neurosci, Sect Neurosurg, Uppsala, Sweden.
    Eriksson, Måns
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Statistics. Uppsala Univ, Dept Stat, Uppsala, Sweden;Univ Edinburgh, Sch Math, Edinburgh, Midlothian, Scotland;Univ Edinburgh, Maxwell Inst Math Sci, Edinburgh, Midlothian, Scotland.
    Enblad, Per
    Kamali-Moghaddam, Masood
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Monitoring of Protein Biomarkers of Inflammation in Human Traumatic Brain Injury Using Microdialysis and Proximity Extension Assay Technology in Neurointensive Care2019In: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 36, no 20, p. 2872-2885Article in journal (Refereed)
    Abstract [en]

    Traumatic brain injury (TBI) is followed by secondary injury mechanisms strongly involving neuroinflammation. To monitor the complex inflammatory cascade in human TBI, we used cerebral microdialysis (MD) and multiplex proximity extension assay (PEA) technology and simultaneously measured levels of 92 protein biomarkers of inflammation in MD samples every three hours for five days in 10 patients with severe TBI under neurointensive care. One mu L MD samples were incubated with paired oligonucleotide-conjugated antibodies binding to each protein, allowing quantification by real-time quantitative polymerase chain reaction. Sixty-nine proteins were suitable for statistical analysis. We found five different patterns with either early (<48 h; e.g., CCL20, IL6, LIF, CCL3), mid (48-96 h; e.g., CCL19, CXCL5, CXCL10, MMP1), late (>96 h; e.g., CD40, MCP2, MCP3), biphasic peaks (e.g., CXCL1, CXCL5, IL8) or stable (e.g., CCL4, DNER, VEGFA)/low trends. High protein levels were observed for e.g., CXCL1, CXCL10, MCP1, MCP2, IL8, while e.g., CCL28 and MCP4 were detected at low levels. Several proteins (CCL8, -19, -20, -23, CXCL1, -5, -6, -9, -11, CST5, DNER, Flt3L, and SIRT2) have not been studied previously in human TBI. Cross-correlation analysis revealed that LIF and CXCL5 may play a central role in the inflammatory cascade. This study provides a unique data set with individual temporal trends for potential inflammatory biomarkers in patients with TBI. We conclude that the combination of MD and PEA is a powerful tool to map the complex inflammatory cascade in the injured human brain. The technique offers new possibilities of protein profiling of complex secondary injury pathways.

  • 14.
    Ekmark-Lewén, Sara
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Flygt, Johanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Fridgeirsdottir, Gudrun A.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Kiwanuka, Olivia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Hanell, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Meyerson, Bengt J.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Mir, Anis K.
    Novartis Inst Biomed Res, Basel, Switzerland..
    Gram, Hermann
    Novartis Inst Biomed Res, Basel, Switzerland..
    Lewen, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Clausen, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Diffuse traumatic axonal injury in mice induces complex behavioural alterations that are normalized by neutralization of interleukin-1β2016In: European Journal of Neuroscience, ISSN 0953-816X, E-ISSN 1460-9568, Vol. 43, no 8, p. 1016-1033Article in journal (Refereed)
    Abstract [en]

    Widespread traumatic axonal injury (TAI) results in brain network dysfunction, which commonly leads to persisting cognitive and behavioural impairments following traumatic brain injury (TBI). TBI induces a complex neuroinflammatory response, frequently located at sites of axonal pathology. The role of the pro-inflammatory cytokine interleukin (IL)-1 has not been established in TAI. An IL-1-neutralizing or a control antibody was administered intraperitoneally at 30min following central fluid percussion injury (cFPI), a mouse model of widespread TAI. Mice subjected to moderate cFPI (n=41) were compared with sham-injured controls (n=20) and untreated, naive mice (n=9). The anti-IL-1 antibody reached the target brain regions in adequate therapeutic concentrations (up to similar to 30g/brain tissue) at 24h post-injury in both cFPI (n=5) and sham-injured (n=3) mice, with lower concentrations at 72h post-injury (up to similar to 18g/g brain tissue in three cFPI mice). Functional outcome was analysed with the multivariate concentric square field (MCSF) test at 2 and 9days post-injury, and the Morris water maze (MWM) at 14-21days post-injury. Following TAI, the IL-1-neutralizing antibody resulted in an improved behavioural outcome, including normalized behavioural profiles in the MCSF test. The performance in the MWM probe (memory) trial was improved, although not in the learning trials. The IL-1-neutralizing treatment did not influence cerebral ventricle size or the number of microglia/macrophages. These findings support the hypothesis that IL-1 is an important contributor to the processes causing complex cognitive and behavioural disturbances following TAI.

  • 15.
    Ekmark-Lewén, Sara
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Flygt, Johanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Kiwanuka, Olivia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Meyerson, Bengt
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Pharmacology.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Traumatic axonal injury in the mouse is accompanied by a dynamic inflammatory response, astroglial reactivity and complex behavioral changes2013In: Journal of Neuroinflammation, ISSN 1742-2094, E-ISSN 1742-2094, Vol. 10, no 1, p. 44-Article in journal (Refereed)
    Abstract [en]

    Background

    Diffuse traumatic axonal injury (TAI), a common consequence of traumatic brain injury, is associated with high morbidity and mortality. Inflammatory processes may play an important role in the pathophysiology of TAI. In the murine central fluid percussion injury (cFPI) TAI model, the neuroinflammatory and astroglial response and behavioral changes are unknown.

    Methods

    Twenty cFPI-injured and nine sham-injured mice were used, and the neuroinflammatory and astroglial response was evaluated by immunohistochemistry at 1, 3 and 7 days post-injury. The multivariate concentric square field test (MCSF) was used to compare complex behavioral changes in mice subjected to cFPI (n = 16) or sham injury (n = 10). Data was analyzed using non-parametric statistics and principal component analysis (MCSF data).

    Results

    At all post-injury time points, beta-amyloid precursor protein (beta-APP) immunoreactivity revealed widespread bilateral axonal injury and IgG immunostaining showed increased blood--brain barrier permeability. Using vimentin and glial fibrillary acidic protein (GFAP) immunohistochemistry, glial cell reactivity was observed in cortical regions and important white matter tracts peaking at three days post-injury. Only vimentin was increased post-injury in the internal capsule and only GFAP in the thalamus. Compared to sham-injured controls, an increased number of activated microglia (MAC-2), infiltrating neutrophils (GR-1) and T-cells (CD3) appearing one day after TAI (P<0.05 for all cell types) was observed in subcortical white matter. In the MCSF, the behavioral patterns including general activity and exploratory behavior differed between cFPI mice and sham-injured controls.

    Conclusions

    Traumatic axonal injury in mice resulted in marked bilateral astroglial and neuroinflammatory responses and complex behavioral changes. The cFPI model in mice appears suitable for the study of injury mechanisms, including neuroinflammation, and the development of treatments targeting traumatic axonal injury.

  • 16.
    Fridgeirsdottir, Gudrun Andrea
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Clausen, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Escalated handling of young C57BL/6 mice results in altered Morris water maze performance2014In: Upsala Journal of Medical Sciences, ISSN 0300-9734, E-ISSN 2000-1967, Vol. 119, no 1, p. 1-9Article in journal (Refereed)
    Abstract [en]

    Background. The handling of experimental animals prior to experimental interventions is often poorly described, even though it may affect the final functional outcome. This study explores how the use of repeated handling of C57BL/6 mice prior to Morris water maze (MWM) tests can affect the performance. Methods and materials. The handled animals were subjected to the escalating handling protocol, with the investigator spending 5 min per day per cage for 8 days prior to the MWM test. On the last days of handling, the mice were introduced to water and the concept of a hidden platform. The MWM test consisted of four daily trials for 90 s per day for 4 days with a hidden platform. A probe test was performed 4 days after the last learning trial. Control animals were not handled prior to MWM. Results. Handling reduced the latency to find the platform on the first 2 days of the MWM tests and reduced thigmotaxis. The mice increased their swim speed and elicited more explorative behavior in the learning trials and to some lesser extent in the probe trials. Conclusions. The improvement in MWM navigation was most likely due to reduced stress and anxiety regarding the investigator and the test. Handled mice displayed less variability than non-handled mice, suggesting that by using a controlled handling protocol prior to the experiments fewer C57BL/6 mice would be needed to achieve statistically significant differences in studies of learning and spatial memory using MWM.

  • 17.
    Hanrieder, Jörg
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Wetterhall, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Temporally resolved differential proteomic analysis of human ventricular CSF for monitoring traumatic brain injury biomarker candidates.2009In: Journal of Neuroscience Methods, ISSN 0165-0270, E-ISSN 1872-678X, Vol. 177, no 2, p. 469-478Article in journal (Refereed)
    Abstract [en]

    A shotgun proteomic approach based on nanoflow liquid chromatography (nanoLC) in conjunction with matrix assisted laser desorption/ionization time of flight tandem mass spectrometry (MALDI TOF MS/MS) was utilized to quantitatively analyze the protein content of consecutive ventricular cerebrospinal fluid (CSF) samples of severe traumatic brain injury (TBI) patients on an individual basis. CSF was acquired from the lateral ventricle 1–9 days after the TBI incident by canula drain to investigate temporally resolved protein changes in three patients that required intracranial pressure monitoring during neurointensive care. The samples were subjected to at once tryptic digestion followed by isobaric tag labeling before multiplexed peptide separation and MS analysis. By using this approach, we were able to follow characteristic changes in protein concentrations over time allowing new conclusions to be drawn about ongoing pathological processes during TBI. Certain suggested protein-biomarker candidates for TBI, like acute phase reactants (APRs), fibrinogens (FIB), cystatin C (CC) or more brain specific proteins like glial fibrillary acid protein (GFAP) and neuron-specific enolase (NSE) were found to be significantly up-regulated which is in strong consistence with previously reported results. This methodology appears to be a promising tool for studying candidate biomarkers of neurovascular and traumatic brain injuries in the neurointensive care setting.

  • 18.
    Hillered, Lars
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Dahlin, Andreas P
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Clausen, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Chu, Jiangtao
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Cerebral microdialysis for protein biomarker monitoring in the neurointensive care setting - a technical approach2014In: Frontiers in Neurology, ISSN 1664-2295, E-ISSN 1664-2295, Vol. 5, p. 245-Article in journal (Refereed)
    Abstract [en]

    Cerebral microdialysis (MD) was introduced as a neurochemical monitoring method in the early 1990s and is currently widely used for the sampling of low molecular weight molecules, signaling energy crisis, and cellular distress in the neurointensive care (NIC) setting. There is a growing interest in MD for harvesting of intracerebral protein biomarkers of secondary injury mechanisms in acute traumatic and neurovascular brain injury in the NIC community. The initial enthusiasm over the opportunity to sample protein biomarkers with high molecular weight cut-off MD catheters has dampened somewhat with the emerging realization of inherent methodological problems including protein-protein interaction, protein adhesion, and biofouling, causing an unstable in vivo performance (i.e., fluid recovery and extraction efficiency) of the MD catheter. This review will focus on the results of a multidisciplinary collaborative effort, within the Uppsala Berzelii Centre for Neurodiagnostics during the past several years, to study the features of the complex process of high molecular weight cut-off MD for protein biomarkers. This research has led to new methodology showing robust in vivo performance with optimized fluid recovery and improved extraction efficiency, allowing for more accurate biomarker monitoring. In combination with evolving analytical methodology allowing for multiplex biomarker analysis in ultra-small MD samples, a new opportunity opens up for high-resolution temporal mapping of secondary injury cascades, such as neuroinflammation and other cell injury reactions directly in the injured human brain. Such data may provide an important basis for improved characterization of complex injuries, e.g., traumatic and neurovascular brain injury, and help in defining targets and treatment windows for neuroprotective drug development.

  • 19.
    Hillered, Lars
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Dahlin, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Purins, Karlis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Wetterhall, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewen, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    New Microdialysis Method for Protein Biomarker Sampling in the Neurointensive Care Setting2014In: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 31, no 5, p. A22-A22Article in journal (Refereed)
  • 20.
    Hillered, Lars
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Nonischemic energy metabolic crisis in acute brain injury2008In: Critical Care Medicine, ISSN 0090-3493, E-ISSN 1530-0293, Vol. 36, no 10, p. 2952-2953Article in journal (Refereed)
  • 21.
    Högberg, Niclas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Paediatric Surgery.
    Carlsson, Per-Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Meurling, Staffan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Paediatric Surgery.
    Stenbäck, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Paediatric Surgery.
    Intestinal ischemia measured by intraluminal microdialysis2012In: Scandinavian Journal of Clinical and Laboratory Investigation, ISSN 0036-5513, E-ISSN 1502-7686, Vol. 72, no 1, p. 59-66Article in journal (Refereed)
    Abstract [en]

    Objective.

    To evaluate the possibility of detecting intestinal ischemia by intraluminal microdialysis and comparing the ileum and colon.

    Methods.

    The studies were performed on male Sprague-Dawley rats. In the fi rst part of the study, microdialysis catheters were placed in the sigmoid part of the colon and in the subcutaneous adipose tissue. In the second part of the study, microdialysis catheters were placed in the lumen of the ileum and the colon. The infrarenal aorta was clamped proximal to the cranial mesenteric artery. Microdialysate levels of glucose, lactate, pyruvate and glycerol were measured. Intestinal specimens were removed at the end of the ischemic period for microscopic evaluation.

    Results.

    Intraluminal microdialysis could detect early signs of ischemic injury in the ileum, as well as in the colon, with a marked increase of lactate, lactate/pyruvate ratio and glycerol. The increased levels of intraluminal glycerol showed a positive correlation to prolonged ischemia and to higher degrees of intestinal damage.

    Conclusion.

    Intraluminal measurement of glycerol is a good marker for intestinal ischemia. Intraluminal microdialysis in the colon is easily accessible through the rectum, and ay prove to be a valuable clinical tool for diagnosing intestinal ischemia.

  • 22.
    Högberg, Niclas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Paediatric Surgery.
    Carlsson, Per-Ola
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Endocrinology, Diabetes and Metabolism.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Stenbäck, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Paediatric Surgery.
    Engstrand Lilja, Helene
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Paediatric Surgery.
    Intraluminal intestinal microdialysis detects markers of hypoxia and cell damage in experimental necrotizing enterocolitis2012In: Journal of Pediatric Surgery, ISSN 0022-3468, E-ISSN 1531-5037, Vol. 47, no 9, p. 1646-1651Article in journal (Refereed)
    Abstract [en]

    BACKGROUND/PURPOSE:

    Necrotizing enterocolitis (NEC) represents one of the gravest complications in premature infants and carries significant morbidity and mortality. There is a great need for improved diagnostic methods to reduce the severity and incidence of NEC. The aim of the study was to investigate if intraluminal microdialysis can detect intestinal ischemia in newborn rats with induced experimental NEC.

    METHODS:

    The studies were performed on 1-day-old Sprague-Dawley rat pups. Experimental NEC was induced using hypoxia/reoxygenation treatment. Microdialysis catheters were rectally inserted and placed in the rectosigmoid part of the colon. Microdialysate levels of glucose, lactate, pyruvate, and glycerol were measured. Intestinal specimens were collected at the end of the experiments for microscopic evaluation.

    RESULTS:

    Intraluminal microdialysis revealed signs of intestinal hypoxia and cellular damage, with a marked increase of lactate and glycerol. Microscopic evaluation confirmed intestinal damage in the NEC group.

    CONCLUSION:

    Intraluminal microdialysis can detect intestinal hypoxic stress and mucosal cell membrane decay in a rat model of NEC. Intestinal intraluminal microdialysis is easily accessible through the rectum and may be a useful noninvasive complement to other methods in the assessment of NEC.

  • 23.
    Israelsson, Charlotte
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Developmental Neuroscience.
    Kylberg, Annika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Developmental Neuroscience.
    Bengtsson, Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Developmental Neuroscience.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Ebendal, Ted
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Developmental Neuroscience.
    Interacting Chemokine Signals Regulate Dendritic Cells in Acute Brain Injury2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 8, p. e104754-Article in journal (Refereed)
    Abstract [en]

    Brain trauma is known to activate inflammatory cells via various chemokine signals although their interactions remain to be characterized. Mice deficient in Ccl3, Ccr2 or Cxcl10 were compared with wildtype mice after controlled cortical impact injury. Expression of Ccl3 in wildtypes was rapidly upregulated in resident, regularly spaced reactive microglia. Ccl3-deficiency enhanced endothelial expression of platelet selectin and invasion of peripheral inflammatory cells. Appearance of Ccr2 transcripts, encoding the Ccl2 receptor, reflected invasion of lysozyme 2-expressing phagocytes and classical antigen-presenting dendritic cells expressing major histocompatibility complex class II. Ccr2 also directed clustered plasmacytoid dendritic cells positive for the T-cell attracting chemokine Cxcl10. A reduction in Ccr2 and dendritic cells was found in injured wildtype cortex after cyclophosphamide treatment resembling effects of Ccr2-deficiency. The findings demonstrate the feasibility to control inflammation in the injured brain by regulating chemokine-dependent pathways.

  • 24.
    Israelsson, Charlotte
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. Develop. Neurosci.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. Neurokirurgi.
    Kylberg, Annika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. Develop. neurosci.
    Usoskin, Dmitry
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. Develop. Neurosci.
    Althini, Susanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. Develop. neurosci.
    Lindeberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. Develop. neurosci.
    Deng, Chu-Xia
    Fukuda, Tomokazu
    Wang, Yun
    Kaartinen, Vesa
    Mishina, Yuji
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. Neurokirurgi.
    Ebendal, Ted
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience. Develop. Neurosci.
    Genetically modified bone morphogenetic protein signalling alters traumatic brain injury-induced gene expression responses in the adult mouse2006In: Journal of Neuroscience Research, ISSN 0360-4012, E-ISSN 1097-4547, Vol. 84, no 1, p. 47-57Article in journal (Refereed)
    Abstract [en]

    Three genetic mouse models were examined to define effects of bone morphogenetic protein (BMP) signalling on gene expression in normal and injured adult brain. CaMKII-Cre eliminated the BMP receptor Acvr1 (Alk2) and the common TGF beta superfamily signal mediator Smad4 or activated a constitutively active Acvr1 in postnatal forebrain neurons. All mutants followed mendelian ratios, with no overt phenotypic changes. In situ hybridization demonstrated normal patterns of the dendritic marker MAP2 (Mtap2) throughout cortex despite neuron-specific losses of Acvr1 or Smad4. However, strong up-regulation of Mtap2 transcript in these mice was found by quantitative RT-PCR (qRT-PCR), indicating that Mtap2 is normally suppressed by BMR Traumatic brain injury (TBI) resulted in increases of histone-associated DNA fragments in both control and Smad4-deficient cortex. Several cell-type-specific transcripts known to be involved in injury-related responses were measured by qRT-PCR. Gfap mRNA was strongly upregulated in controls as well as in the loss-of-BMP-signalling mutants. Notably, activated Acvr1 signalling gave significantly lower TBI-induced up-regulations of Gfap and Phox2a mRNA levels, indicating reductions in astroglial and neuronal reactions to injury. Strong impairment in injury-induced Timp1 transcript up-regulation was also seen in these mice. In contrast, osteopontin (Spp1) transcript levels in activated microglia were not reduced by Acvr1 signalling. Altogether, the data suggest that BMP signalling is dispensable in adult cortical neurons but that augmented BMP signalling affects molecular changes associated with neuronal lesions.

  • 25. Kenne, Ellinor
    et al.
    Erlandsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lindbom, Lennart
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Clausen, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Neutrophil depletion reduces edema formation and tissue loss following traumatic brain injury in mice2012In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 26Article in journal (Other academic)
  • 26. Kenne, Ellinor
    et al.
    Erlandsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lindbom, Lennart
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Clausen, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Neutrophil depletion reduces edema formation and tissue loss following traumatic brain injury in mice2012In: Journal of Neuroinflammation, ISSN 1742-2094, E-ISSN 1742-2094, Vol. 9, p. 17-Article in journal (Refereed)
    Abstract [en]

    Background: Brain edema as a result of secondary injury following traumatic brain injury (TBI) is a major clinical concern. Neutrophils are known to cause increased vascular permeability leading to edema formation in peripheral tissue, but their role in the pathology following TBI remains unclear.

    Methods: In this study we used controlled cortical impact (CCI) as a model for TBI and investigated the role of neutrophils in the response to injury. The outcome of mice that were depleted of neutrophils using an anti-Gr-1 antibody was compared to that in mice with intact neutrophil count. The effect of neutrophil depletion on blood-brain barrier function was assessed by Evan's blue dye extravasation, and analysis of brain water content was used as a measurement of brain edema formation (24 and 48 hours after CCI). Lesion volume was measured 7 and 14 days after CCI. Immunohistochemistry was used to assess cell death, using a marker for cleaved caspase-3 at 24 hours after injury, and microglial/macrophage activation 7 days after CCI. Data were analyzed using Mann-Whitney test for non-parametric data.

    Results: Neutrophil depletion did not significantly affect Evan's blue extravasation at any time-point after CCI. However, neutrophil-depleted mice exhibited a decreased water content both at 24 and 48 hours after CCI indicating reduced edema formation. Furthermore, brain tissue loss was attenuated in neutropenic mice at 7 and 14 days after injury. Additionally, these mice had a significantly reduced number of activated microglia/macrophages 7 days after CCI, and of cleaved caspase-3 positive cells 24 h after injury.

    Conclusion: Our results suggest that neutrophils are involved in the edema formation, but not the extravasation of large proteins, as well as contributing to cell death and tissue loss following TBI in mice.

  • 27. Kocak, Oyku
    et al.
    Fridgeirsdottir, Gudrun Andrea
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Clausen, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Endogenous free radical production by NADPH oxidase 2 contributes to the secondary injury cascade after traumatic brain injury in mice2012In: Brain Injury, ISSN 0269-9052, E-ISSN 1362-301X, Vol. 26, no 4-5, p. 503-504Article in journal (Other academic)
  • 28.
    Kunz, T
    et al.
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Marklund, Niklas
    Faculty of Medicine, Department of Neuroscience. Neurokirurgi.
    Hillered, Lars
    Faculty of Medicine, Department of Neuroscience. Neurokirurgi.
    Oliw, EH
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    Effects of the selective cyclooxygenase-2 inhibitor rofecoxib on cell death following traumatic brain injury in the rat2006In: Restor Neurol Neurosci, Vol. 24, no 1, p. 55-63Article in journal (Refereed)
  • 29.
    Larsson, Anders
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Chemistry.
    Lindqvist, A.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Chemistry.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Pseudoparaproteinemia Detected by CE due to Omnipaque™ Infusion: A Case Report2007In: Chromatographia, ISSN 0009-5893, E-ISSN 1612-1112, Vol. 65, no 11-12, p. 775-777Article in journal (Refereed)
    Abstract [en]

    Serum or plasma protein electrophoresis is often performed in clinical laboratories to detect and monitor M-components. During the last decade, capillary electrophoresis (CE) has emerged as an interesting alternative to traditional analysis of serum, plasma and urine proteins by agarose gel electrophoresis. We here report a case of pseudoparaproteinemia detected by capillary electrophoresis after Omnipaque™ (iohexol) infusion in a patient with normal kidney function. It is important for the laboratories to be aware of this source of erroneous results and not misclassify it as monoclonal gammopathies.

  • 30.
    Lewén, Anders
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Dyhrfort, Philip
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Clausen, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    A Dedicated 21-Plex Pea Panel For High-Sensitive Protein Biomarker Detection Using Micro-Dialysis In Traumatic Brain Injury2018In: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 35, no 16, p. A130-A130Article in journal (Other academic)
  • 31.
    Lindblom, Rickard P F
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Thoracic Surgery.
    Tovedal, Thomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Norlin, Bo
    Uppsala Univ Hosp, Dept Cardiothorac Surg & Anesthesia, SE-75185 Uppsala, Sweden.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Popova, Svetlana
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Alafuzoff, Irina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Thelin, Stefan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Thoracic Surgery.
    Mechanical reperfusion with leucocyte-filtered blood does not prevent injury following global cerebral ischaemia2017In: European Journal of Cardio-Thoracic Surgery, ISSN 1010-7940, E-ISSN 1873-734X, Vol. 51, no 4, p. 773-781Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: Prolonged global cerebral ischaemia leads to irreversible injury, often with lethal outcome. Brain injuries are partly caused by the uncontrolled reperfusion that occurs once the circulation is re-established. Recent animal experiments suggest that controlled reperfusion following lengthy ischaemia might prevent severe brain injury. This study aimed at further exploring cerebral alterations and outcome following prolonged global cerebral ischaemia and mechanically manipulated reperfusion.

    METHODS: Three groups of pigs were included; one sham operated (n = 3) and two that underwent 30-min global cerebral ischaemia. All vessels that supply the brain were isolated intrathoracically, after which they were occluded for 30 min in the ischaemic groups. In one of the ischaemic groups uncontrolled reperfusion was applied (URep, n = 6), i.e. normal circulation was restored 30 min after arrested cerebral circulation. The second ischaemic group received mechanical reperfusion (MRep, n = 6) with leucocyte-filtered blood at constant flow and pressure for 20 min using extracorporeal circulation following the 30-min ischaemia, after which normal blood flow resumed. All animals were monitored for 3 h after start of uncontrolled reperfusion. Haemodynamic parameters, arterial and sagittal sinus blood gases, cerebral oxygen extraction rates and intraparenchymal biomarkers using microdialysis were measured. Brain histology was performed post-mortem.

    RESULTS: Global brain ischaemia led to the same extent of severe morphological changes at the level of light microscopy in the two ischaemic experimental groups, regardless of reperfusion protocol. Furthermore, no significant differences were found between the URep and MRep groups regarding cerebral blood gases or microdialysis biomarkers.

    CONCLUSIONS: Mechanical reperfusion following the current protocol does not modify brain alterations caused by 30 min of arrested cerebral circulation.

  • 32.
    Loov, Camilla
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Shevchenko, Ganna
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Nadadhur, Aishwarya Geeyarpuram
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Clausen, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Wetterhall, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Erlandsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Identification of Injury Specific Proteins in a Cell Culture Model of Traumatic Brain Injury2013In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 2, p. e55983-Article in journal (Refereed)
    Abstract [en]

    The complicated secondary molecular and cellular mechanisms following traumatic brain injury (TBI) are still not fully understood. In the present study, we have used mass spectrometry to identify injury specific proteins in an in vitro model of TBI. A standardized injury was induced by scalpel cuts through a mixed cell culture of astrocytes, oligodendrocytes and neurons. Twenty-four hours after the injury, cell culture medium and whole-cell fractions were collected for analysis. We found 53 medium proteins and 46 cell fraction proteins that were specifically expressed after injury and the known function of these proteins was elucidated by an extensive literature survey. By using time-lapse microscopy and immunostainings we could link a large proportion of the proteins to specific cellular processes that occur in response to trauma; including cell death, proliferation, lamellipodia formation, axonal regeneration, actin remodeling, migration and inflammation. A high percentage of the proteins uniquely expressed in the medium after injury were actin-related proteins, which normally are situated intracellularly. We show that two of these, ezrin and moesin, are expressed by astrocytes both in the cell culture model and in mouse brain subjected to experimental TBI. Interestingly, we found many inflammation-related proteins, despite the fact that cells were present in the culture. This study contributes with important knowledge about the cellular responses after trauma and identifies several potential cell-specific biomarkers.

  • 33.
    Lööv, Camilla
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Developmental Neuroscience.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Ebendal, Ted
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Developmental Neuroscience.
    Erlandsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Engulfing Astrocytes Protect Neurons from Contact-Induced Apoptosis following Injury2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 3, p. e33090-Article in journal (Refereed)
    Abstract [en]

    Clearing of dead cells is a fundamental process to limit tissue damage following brain injury. Engulfment has classically been believed to be performed by professional phagocytes, but recent data show that non-professional phagocytes are highly involved in the removal of cell corpses in various situations. The role of astrocytes in cell clearance following trauma has however not been studied in detail. We have found that astrocytes actively collect and engulf whole dead cells in an in vitro model of brain injury and thereby protect healthy neurons from bystander cell death. Time-lapse experiments showed that migrating neurons that come in contact with free-floating cell corpses induced apoptosis, while neurons that migrate through groups of dead cells, garnered by astrocytes, remain unaffected. Furthermore, apoptotic cells are present within astrocytes in the mouse brain following traumatic brain injury (TBI), indicating a possible role for astrocytes in engulfment of apoptotic cells in vivo. qRT-PCR analysis showed that members of both ced pathways and Megf8 are expressed in the cell culture, indicating their possible involvement in astrocytic engulfment. Moreover, addition of dead cells had a positive effect on the protein expression of MEGF10, an ortholog to CED1, known to initiate phagocytosis by binding to phosphatidylserine. Although cultured astrocytes have an immense capacity for engulfment, seemingly without adverse effects, the ingested material is stored rather than degraded. This finding might explain the multinuclear astrocytes that are found at the lesion site in patients with various brain disorders.

  • 34.
    Lööv, Camilla
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Nadadhur, Aishwarya
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Clausen, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Erlandsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Extracellular Ezrin - a Novel Biomarker for Traumatic Brain Injury2015In: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 32, no 4, p. 244-251Article in journal (Refereed)
    Abstract [en]

    Traumatic brain injury (TBI) is a heterogeneous disease, and the discovery of diagnostic and prognostic TBI biomarkers is highly desirable in order to individualize patient care. We have previously published a study in which we identified possible TBI biomarkers by mass spectrometry 24 h after injury in a cell culture model. Ezrin-radixin-moesin (ERM) proteins were found abundantly in the medium after trauma, and in the present study we have identified extracellular ezrin as a possible biomarker for brain trauma by analyzing cell culture medium from injured primary neurons and glia and by measuring ezrin in cerebrospinal fluid (CSF) from both rats and humans. Our results show that extracellular ezrin concentration was substantially increased in cell culture medium after injury, but that the intracellular expression of the protein remained stable over time. Controlled cortical impact injured rats showed an increased amount of ezrin in CSF at both day 3 and day 7 after trauma. Moreover, ezrin was present in all ventricular CSF samples from seven humans with severe TBI. In contrast to intracellular ezrin, which is distinctly activated following TBI, extracellular ezrin is nonphosphorylated. This is the first report of extracellular ERM proteins in human and experimental models of TBI, providing a scientific foundation for further assessment of ezrin as a potential biomarker.

  • 35.
    Lööv, Camilla
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Shevchenko, Ganna
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Wetterhall, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Erlandsson, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Identification of unique proteins after injury in a cell culture model of TBI2012In: Brain Injury, ISSN 0269-9052, E-ISSN 1362-301X, Vol. 26, no 4-5, p. 487-488Article in journal (Other academic)
  • 36.
    Marklund, Niklas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Farrokhnia, Nina
    Hanell, Anders
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Zetterberg, Henrik
    Blennow, Kaj
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Monitoring of amyloid-beta dynamics after human traumatic brain injury2012In: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 29, no 10, p. A185-A185Article in journal (Other academic)
  • 37.
    Marklund, Niklas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Farrokhnia, Nina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hånell, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Vanmechelen, Eugeen
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Zetterberg, Henrik
    Blennow, Kaj
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Monitoring of beta-Amyloid Dynamics after Human Traumatic Brain Injury2014In: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 31, no 1, p. 42-55Article in journal (Refereed)
    Abstract [en]

    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- (A) peptides playing key pathophysiological roles in AD. We used cerebral microdialysis (MD) to test the hypothesis that interstitial A 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 A1-40 (A40; n=765 samples) and A1-42 (A42; n=765 samples) in pooled 2h fractions up to 14 days post-injury, using the Luminex xMAP technique, allowing detection with high temporal resolution of the key A peptides A40 and A42. Data are presented using medians and 25th and 75th percentiles. Both A40 and A42 were consistently higher in patients with predominately diffuse axonal injury compared with patients with focal TBI at days 1-6 post- injury, A42 being significantly increased at 113-116h post-injury (p<0.05). The A 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 A species may occur following human TBI, particularly related to axonal injury.

  • 38.
    Marklund, Niklas
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Salci, Konstantin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Ronquist, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Energy metabolic changes in the early post-injury period following traumatic brain injury in rats2006In: Neurochemical Research, ISSN 0364-3190, E-ISSN 1573-6903, Vol. 31, no 8, p. 1085-1093Article in journal (Refereed)
    Abstract [en]

    Impaired cerebral energy metabolism may be a major contributor to the secondary injury cascade that occurs following traumatic brain injury (TBI). To estimate the cortical energy metabolic state following mild and severe controlled cortical contusion (CCC) TBI in rats, ipsi-and contralateral cortical tissues were frozen in situ at 15 and 40 min post-injury and adenylate (ATP, ADP, AMP) levels were analyzed using high-performance liquid chromatography (HPLC) and the energy charge (EC) was calculated. At 15 min post-injury, mildly brain-injured animals showed a 43% decrease in cortical ATP levels and a 2.4-fold increase in AMP levels (P < 0.05), and there was a significant reduction of the ipsilateral cortical EC when compared to sham-injured animals (P < 0.05). At 40 min post-injury, the ipsilateral adenylate levels and EC had recovered to the values observed in the sham-injury group. In the severe CCC group, there was a 51% decrease in ipsilateral cortical ATP levels and a 5.3-fold increase in AMP levels with a significant reduction of cortical EC at 15 min post-injury (P < 0.05). At 40 min post-injury, a 2.6-fold ipsilateral increase in AMP levels and an 11% and 44% decrease in EC and ATP levels, respectively, remained (P < 0.05). A 37–38% reduction of the total adenylate pool was observed ipsilaterally in both CCC severity groups at the early time-point, and a 19% and 28% decrease remained in the mild and severe CCC groups, respectively, at 40 min post-injury. Significant contralateral ATP and EC changes were only observed in the severe CCC group at 40 min post-injury (P < 0.05). The energy-requiring secondary injury cascades that occur early post-injury do not challenge the brain tissue to the extent of ATP depletion and may provide a window of opportunity for therapeutic intervention.

  • 39.
    Nyberg, Christoffer
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Karlsson, Torbjörn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Metabolic Pattern of the Acute Phase of Subarachnoid Hemorrhage in a Novel Porcine Model: Studies with Cerebral Microdialysis with High Temporal Resolution2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 6, p. e99904-Article in journal (Refereed)
    Abstract [en]

    Background: Aneurysmal subarachnoid hemorrhage (SAH) may produce cerebral ischemia and systemic responses including stress. To study immediate cerebral and systemic changes in response to aneurysm rupture, animal models are needed. Objective: To study early cerebral energy changes in an animal model. Methods: Experimental SAH was induced in 11 pigs by autologous blood injection to the anterior skull base, with simultaneous control of intracranial and cerebral perfusion pressures. Intracerebral microdialysis was used to monitor concentrations of glucose, pyruvate and lactate. Results: In nine of the pigs, a pattern of transient ischemia was produced, with a dramatic reduction of cerebral perfusion pressure soon after blood injection, associated with a quick glucose and pyruvate decrease. This was followed by a lactate increase and a delayed pyruvate increase, producing a marked but short elevation of the lactate/pyruvate ratio. Glucose, pyruvate, lactate and lactate/pyruvate ratio thereafter returned toward baseline. The two remaining pigs had a more severe metabolic reaction with glucose and pyruvate rapidly decreasing to undetectable levels while lactate increased and remained elevated, suggesting persisting ischemia. Conclusion: The animal model simulates the conditions of SAH not only by deposition of blood in the basal cisterns, but also creating the transient global ischemic impact of aneurysmal SAH. The metabolic cerebral changes suggest immediate transient substrate failure followed by hypermetabolism of glucose upon reperfusion. The model has features that resemble spontaneous bleeding, and is suitable for future research of the early cerebral and systemic responses to SAH that are difficult to study in humans.

  • 40.
    Nyberg, Christoffer
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Karlsson, Torbjörn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Stridsberg, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Biochemical endocrinology.
    Engström, Elisabeth Ronne
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    The Early Endocrine Stress Response in Experimental Subarachnoid Hemorrhage2016In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 3, article id e0151457Article in journal (Refereed)
    Abstract [en]

    Introduction In patients with severe illness, such as aneurysmal subarachnoid hemorrhage (SAH), a physiologic stress response is triggered. This includes activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system. The aim of this study was to investigate the very early responses of these systems. Methods A porcine animal model of aneurysmal SAH was used. In this model, blood is injected slowly to the basal cisterns above the anterior skull base until the cerebral perfusion pressure is 0 mm Hg. Sampling was done from blood and urine at -10, +15, +75 and +135 minutes from time of induction of SAH. Analyses of adrenocorticotropic hormone (ACTH), cortisol, aldosterone, catecholamines and chromogranin-A were performed. Results Plasma ACTH, serum cortisol and plasma aldosterone increased in the samples following induction of SAH, and started to decline after 75 minutes. Urine cortisol also increased after SAH. Urine catecholamines and their metabolites were found to increase after SAH. Many samples were however below detection level, not allowing for statistical analysis. Plasma chromogranin-A peaked at 15 minutes after SAH, and thereafter decreased. Conclusions The endocrine stress response after aneurysmal SAH was found to start within 15 minutes in the HPA axis with early peak values of ACTH, cortisol and aldosterone. The fact that the concentrations of the HPA axis hormones decreased 135 minutes after SAH may suggest that a similar pattern exists in SAH patients, thus making it difficult to catch these early peak values. There were also indications of early activation of the sympathetic nervous system, but the small number of valid samples made interpretation difficult.

  • 41.
    Nyholm, Lena
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Howells, Timothy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    The influence of hyperthermia on intracranial pressure, cerebral oximetry and cerebral metabolism in traumatic brain injury2017In: Upsala Journal of Medical Sciences, ISSN 0300-9734, E-ISSN 2000-1967, Vol. 122, no 3, p. 177-184Article in journal (Refereed)
    Abstract [en]

    Background: Hyperthermia is a common secondary insult in traumatic brain injury (TBI). The aim was to evaluate the relationship between hyperthermia and intracranial pressure (ICP), and if intracranial compliance and cerebral blood flow (CBF) pressure autoregulation affected that relationship. The relationships between hyperthermia and cerebral oximetry (B(ti)pO(2)) and cerebral metabolism were also studied. Methods: A computerized multimodality monitoring system was used for data collection at the neurointensive care unit. Demographic and monitoring data (temperature, ICP, blood pressure, microdialysis, B(ti)pO(2)) were analyzed from 87 consecutive TBI patients. ICP amplitude was used as measure of compliance, and CBF pressure autoregulation status was calculated using collected blood pressure and ICP values. Mixed models and comparison between groups were used. Results: The influence of hyperthermia on intracranial dynamics (ICP, brain energy metabolism, and B(ti)pO(2)) was small, but individual differences were seen. Linear mixed models showed that hyperthermia raises ICP slightly more when temperature increases in the groups with low compliance and impaired CBF pressure autoregulation. There was also a tendency (not statistically significant) for increased B(ti)pO(2), and for increased pyruvate and lactate, with higher temperature, while the lactate/pyruvate ratio and glucose were stable. Conclusions: The major finding was that the effects of hyperthermia on intracranial dynamics (ICP, brain energy metabolism, and B(ti)pO(2)) were not extensive in general, but there were exceptional cases. Hyperthermia treatment has many side effects, so it is desirable to identify cases in which hyperthermia is dangerous. Information from multimodality monitoring may be used to guide treatment in individual patients.

  • 42.
    Purins, Karlis
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Howells, Timothy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Brain tissue oxygenation and cerebral metabolic patterns in focal and diffuse traumatic brain injury2014In: Frontiers in Neurology, ISSN 1664-2295, E-ISSN 1664-2295, Vol. 5, article id 64Article in journal (Refereed)
    Abstract [en]

    Introduction: Neurointensive care of traumatic brain injury (TBI) patients is currently based on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) targeted protocols. There are reasons to believe that knowledge of brain tissue oxygenation (BtipO2) would add information with the potential of improving patient outcome. The aim of this study was to examine BtipO2 and cerebral metabolism using the Neurovent-PTO probe and cerebral microdialysis (MD) in TBI patients.

    Methods: Twenty-three severe TBI patients with monitoring of physiological parameters, ICP, CPP, BtipO2, and MD for biomarkers of energy metabolism (glucose, lactate, and pyruvate) and cellular distress (glutamate, glycerol) were included. Patients were grouped according to injury type (focal/diffuse) and placement of the Neurovent-PTO probe and MD catheter (injured/non-injured hemisphere).

    Results: We observed different patterns in BtipO2 and MD biomarkers in diffuse and focal injury where placement of the probe also influenced the results (ipsilateral/contralateral). In all groups, despite fairly normal levels of ICP and CPP, increased MD levels of glutamate, glycerol, or the L/P ratio were observed at BtipO2 <5 mmHg, indicating increased vulnerability of the brain at this level.

    Conclusion: Monitoring of BtipO2 adds important information in addition to traditional ICP and CPP surveillance. Because of the different metabolic responses to very low BtipO2 in the individual patient groups we submit that brain tissue oximetry is a complementary tool rather than an alternative to MD monitoring.

  • 43.
    Rostami, Elham
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Engquist, Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Howells, Timothy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Johnson, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Nilsson, Pelle
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Early low cerebral blood flow and high cerebral lactate: prediction of delayed cerebral ischemia in subarachnoid hemorrhage2018In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 128, no 6, p. 1762-1770Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE Delayed cerebral ischemia (DCI) following subarachnoid hemorrhage (SAH) is one of the major contributors to poor outcome. It is crucial to be able to detect early signs of DCI to prevent its occurrence. The objective of this study was to determine if low cerebral blood flow (CBF) measurements and pathological microdialysis parameters measured at the bedside can be observed early in patients with SAH who later developed DCI. METHODS The authors included 30 patients with severe SAH. The CBF measurements were performed at Day 0-3 after disease onset, using bedside xenon-CT. Interstitial glucose, lactate, pyruvate, glycerol, and glutamate were measured using microdialysis. RESULTS Nine of 30 patients developed DCI. Patients with DCI showed significantly lower global and regional CBF, and lactate was significantly increased in these patients. A high lactate/pyruvate ratio was also detected in patients with DCI. CONCLUSIONS Early low CBF measurements and a high lactate and lactate/pyruvate ratio may be early warning signs of the risk of developing DCI. The clinical value of these findings needs to be confirmed in larger studies.

  • 44.
    Rostami, Elham
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Engquist, Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Howells, Timothy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Nilsson, Pelle
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars Tomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    The Correlation between Cerebral Blood Flow Measured by Bedside Xenon-CT and Brain Chemistry Monitored by Microdialysis in the Acute Phase following Subarachnoid Hemorrhage2017In: Frontiers in Neurology, ISSN 1664-2295, E-ISSN 1664-2295, Vol. 8, article id 369Article in journal (Refereed)
    Abstract [en]

    Cerebral microdialysis (MD) may be used in patients suffering from subarachnoid hemorrhage (SAH) to detect focal cerebral ischemia. The cerebral MD catheter is usually placed in the right frontal lobe and monitors the area surrounding the catheter. This generates the concern that a fall in cerebral blood flow (CBF) and ischemic events distant to the catheter may not be detected. We aimed to investigate if there is a difference in the association between the MD parameters and CBF measured around the MD catheter compared to global cortical CBF and to CBF in the vascular territories following SAH in the early acute phase. MD catheter was placed in the right frontal lobe of 30 SAH patients, and interstitial glucose, lactate, pyruvate, glycerol, and lactate/pyruvate ratio were measured hourly. CBF measurements were performed during day 0-3 after SAH. Global cortical CBF correlated strongly with CBF around the microdialysis catheter (CBF-MD) (r = 0.911, p ≤ 0.001). This was also the case for the anterior, middle, and posterior vascular territories in the right hemisphere. A significant negative correlation was seen between lactate and CBF-MD (r = -0.468, p = 0.009). The same relationship was observed between lactate and CBF in anterior vascular territory but not in the middle and posterior vascular territories. In conclusion, global CBF 0-3 days after severe SAH correlated strongly with CBF-MD. High lactate level was associated with low global CBF and low regional CBF in the right anterior vascular territory, when the MD catheter was placed in the right frontal lobe.

  • 45.
    Rostami, Elham
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Engquist, Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Johnson, Ulf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Howells, Timothy
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Nilsson, Pelle
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Monitoring of Cerebral Blood Flow and Metabolism Bedside in Patients with Subarachnoid Hemorrhage - A Xenon-CT and Microdialysis Study2014In: Frontiers in Neurology, ISSN 1664-2295, E-ISSN 1664-2295, Vol. 5, article id 89Article in journal (Refereed)
    Abstract [en]

    Cerebral ischemia is the leading cause of morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH). Although 70% of the patients show angiographic vasospasm only 30% develop symptomatic vasospasm defined as delayed cerebral ischemia (DCI). Early detection and management of reversible ischemia is of critical importance in patients with SAH. Using a bedside Xenon enhanced computerized tomography (Xenon-CT) scanner makes it possible to measure quantitative regional Cerebral blood flow (CBF) bedside in the neurointensive care setting and intracerebral microdialysis (MD) is a method that offers the possibility to monitor the metabolic state of the brain continuously. Here, we present results from nine SAH patients with both MD monitoring and bedside Xenon-CT measurements. CBF measurements were performed within the first 72 h following bleeding. Six out of nine patients developed DCI at a later stage. Five out of six patients who developed DCI had initial global CBF below 26 ml/100 g/min whereas one had 53 ml/100 g/min. The three patients who did not develop clinical vasospasm all had initial global CBF above 27 ml/100 g/min. High lactate/pyruvate (L/P) ratio was associated with lower CBF values in the area surrounding the catheter. Five out of nine patients had L/P ratio ≥25 and four of these patients had CBF ≤ 22 ml/100 g/min. These preliminary results suggest that patients with initially low global CBF on Xenon-CT may be more likely to develop DCI. Initially low global CBF was accompanied with metabolic disturbances determined by the MD. Most importantly, pathological findings on the Xenon-CT and MD could be observed before any clinical signs of DCI. Combining bedside Xenon-CT and MD was found to be useful and feasible. Further studies are needed to evaluate if DCI can be detected before any other signs of DCI to prevent progress to infarction.

  • 46.
    Samuelsson, Carolina
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Zetterling, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hesselager, Göran
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Ryttlefors, Mats
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Kumlien, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Nilsson, Pelle
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Salci, Konstantin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Ronne-Engström, Elisabeth
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Cerebral glutamine and glutamate levels in relation to compromised energy metabolism: a microdialysis study in subarachnoid hemorrhage patients2007In: Journal of Cerebral Blood Flow and Metabolism, ISSN 0271-678X, E-ISSN 1559-7016, Vol. 27, no 7, p. 1309-1317Article in journal (Refereed)
    Abstract [en]

    Astrocytic glutamate (Glt) uptake keeps brain interstitial Glt levels low. Within the astrocytes Glt is converted to glutamine (Gln), which is released and reconverted to Glt in neurons. The Glt–Gln cycle is energy demanding and impaired energy metabolism has been suggested to cause low interstitial Gln/Glt ratios. Using microdialysis (MD) measurements from visually noninjured cortex in 33 neurointensive care patients with subarachnoid hemorrhage, we have determined how interstitial Glt and Gln, as a reflection of the Glt–Gln cycle turnover, relate to perturbed energy metabolism. A total of 3703 hourly samples were analyzed. The lactate/pyruvate (L/P) ratios correlated to the Gln/Glt ratios (r=-0.66), but this correlation was not stronger than the correlation between L/P and Glt (r=0.68) or the correlation between lactate and Glt (r=0.65). A novel observation was a linear relationship between interstitial pyruvate and Gln (r=0.52). There were 13 periods (404 h) of 'energy crisis', defined by L/P ratios above 40. All were associated with high interstitial Glt levels. Periods with L/P ratios above 40 and low pyruvate levels were associated with decreased interstitial Gln levels, suggesting ischemia and failing astrocytic Gln synthesis. Periods with L/P ratios above 40 and normal or high pyruvate levels were associated with increased interstitial Gln levels, which may represent an astrocytic hyperglycolytic response to high interstitial Glt levels. The results imply that moderately elevated L/P ratios cannot always be interpreted as failing energy metabolism and that interstitial pyruvate levels may discriminate whether or not there is sufficient astrocytic capacity for Glt–Gln cycling in the brain.

  • 47.
    Skoglund, Karin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    The neurological wake-up test increases stress hormone levels in patients with severe traumatic brain injury2012In: Critical Care Medicine, ISSN 0090-3493, E-ISSN 1530-0293, Vol. 40, no 1, p. 216-222Article in journal (Refereed)
    Abstract [en]

    Objectives: The "neurological wake-up test" is needed to evaluate the level of consciousness in patients with severe traumatic brain injury. However, the neurological wake-up test requires interruption of continuous sedation and may induce a stress response and its use in neurocritical care is controversial. We hypothesized that the neurological wake-up test induces an additional biochemical stress response in patients with severe traumatic brain injury.

    Patients: Twenty-four patients who received continuous propofol sedation and mechanical ventilation after moderate to severe traumatic brain injury (Glasgow Coma Scale score <= 8; patient age 18-71 yrs old) were analyzed. Exclusion criteria were age <18 yrs old, ongoing pentobarbital infusion, or markedly increased intracranial pressure on interruption of continuous sedation.

    Design: Single-center prospective study. During postinjury days 1-8, 65 neurological wake-up tests were evaluated. Adrenocorticotrophic hormone, epinephrine, and norepinephrine levels in plasma and cortisol levels in saliva were analyzed at baseline (during continuous intravenous propofol sedation) and during neurological wake-up test. Data are presented using medians and 25th and 75th percentiles.

    Setting: The study was performed in a university hospital neurocritical care unit.

    Interventions: None.

    Measurements and Main Results: At baseline, adrenocorticotrophic hormone and cortisol levels were 10.6 (6.0-19.4) ng/L and 16.0 (10.7-31.8) nmol/L, respectively. Immediately after the neurological wake-up test, adrenocorticotrophic hormone levels increased to 20.5 (11.1-48.4) ng/L (p < .05) and cortisol levels in saliva increased to 24.0 (12.3-42.5) nmol/L (p < .05). The plasma epinephrine and norepinephrine levels increased from a baseline of 0.3 (0.3-0.6) and 1.6 (0.9-2.3) nmol/L, respectively, to 0.75 (0.3-1.4) and 2.8 (1.28-3.58) nmol/L, respectively (both p < .05).

    Conclusions: The neurological wake-up test induces a biochemical stress response in patients with severe traumatic brain injury. The clinical importance of this stress response remains to be established but should be considered when deciding the frequency and use of the neurological wake-up test during neurocritical care.

  • 48.
    Skoglund, Karin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Wake-up test and stress hormone levels in patients with brain injury: A focus on mechanisms involved: Reply2012In: Critical Care Medicine, ISSN 0090-3493, E-ISSN 1530-0293, Vol. 40, no 6, p. 2002-2003Article in journal (Refereed)
  • 49.
    Skoglund, Karin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Purins, Karlis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Tsitsopoulos, Parmenion P.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Flygt, Johanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Engquist, Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Lewen, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    The Neurological Wake-up Test Does not Alter Cerebral Energy Metabolism and Oxygenation in Patients with Severe Traumatic Brain Injury2014In: Neurocritical Care, ISSN 1541-6933, E-ISSN 1556-0961, Vol. 20, no 3, p. 413-426Article in journal (Refereed)
    Abstract [en]

    The neurological wake-up test (NWT) is used to monitor the level of consciousness in patients with traumatic brain injury (TBI). However, it requires interruption of sedation and may elicit a stress response. We evaluated the effects of the NWT using cerebral microdialysis (MD), brain tissue oxygenation (PbtiO2), jugular venous oxygen saturation (SjvO(2)), and/or arterial-venous difference (AVD) for glucose, lactate, and oxygen in patients with severe TBI. Seventeen intubated TBI patients (age 16-74 years) were sedated using continuous propofol infusion. All patients received intracranial pressure (ICP) and cerebral perfusion pressure (CPP) monitoring in addition to MD, PbtiO2 and/or SjvO(2). Up to 10 days post-injury, ICP, CPP, PbtiO2 (51 NWTs), MD (49 NWTs), and/or SjvO(2) (18 NWTs) levels during propofol sedation (baseline) and NWT were compared. MD was evaluated at a flow rate of 1.0 mu L/min (28 NWTs) or the routine 0.3 mu L/min rate (21 NWTs). The NWT increased ICP and CPP levels (p < 0.05). Compared to baseline, interstitial levels of glucose, lactate, pyruvate, glutamate, glycerol, and the lactate/pyruvate ratio were unaltered by the NWT. Pathological SjvO(2) (< 50 % or > 71 %; n = 2 NWTs) and PbtiO2 (< 10 mmHg; n = 3 NWTs) values were rare at baseline and did not change following NWT. Finally, the NWT did not alter the AVD of glucose, lactate, or oxygen. The NWT-induced stress response resulted in increased ICP and CPP levels although it did not negatively alter focal neurochemistry or cerebral oxygenation in TBI patients.

  • 50. Skoglund, Karin
    et al.
    Hillered, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Tsitsopoulos, Parmenion
    Engquist, Henrik
    Purins, Karlis
    Lewén, Anders
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    The neurological wake-up test does not negatively influence brain oxygentaion and interstitial markers of cerebral energy metabolism in patients with severe traumatic brain injuryManuscript (preprint) (Other academic)
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