Improving the recovery of S100B protein in cerebral microdialysis: Implications for multimodal monitoring in neurocritical care

Afinowi, R.; Tisdall, Martin; Keir, Geoff; Smith, Martin; Kitchen, Neil; Petzold, Axel

doi:10.1016/j.jneumeth.2009.02.021

Cited by 16 publications

(7 citation statements)

References 34 publications

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“…These studies have focused on a general description of the proteome or selective study of unique proteins as predictive biomarkers. A variety of cytoskeletal and neuronal proteins such as S100B, neuron-specific enolase (NSE), myelin-basic protein (MBP), and glial fibrillary acidic protein (GFAP) have been detected in these studies [13–15]. Interpretation of proteomic studies on serum is challenging since the proteins or proteolytic fragments from the damaged brain tissue are reabsorbed via the arachnoid villie into the blood [7] and this may lead to additional dilution effects.…”

Section: Discussionmentioning

confidence: 99%

Metabolic Crisis After Traumatic Brain Injury is Associated with a Novel Microdialysis Proteome

et al. 2010

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Background To examine if the metabolic distress after traumatic brain injury (TBI) is associated with a unique proteome. Methods Patients with severe TBI prospectively underwent cerebral microdialysis for the initial 96 h after injury. Hourly sampling of metabolism was performed and patients were categorized as having normal or abnormal metabolism as evidenced by the lactate/pyruvate ratio (LPR) threshold of 40. The microdialysate was frozen for proteomic batch processing retrospectively. We employed two different routes of proteomic techniques utilizing mass spectrometry (MS) and categorized as diagnostic and biomarker identification approaches. The diagnostic approach was aimed at finding a signature of MS peaks which can differentiate these two groups. We did this by enriching for intact peptides followed by MALDI-MS analysis. For the biomarker identification approach, we applied classical bottom-up (trypsin digestion followed by LC-MS/MS) proteomic methodologies. Results Five patients were studied, 3 of whom had abnormal metabolism and 2 who had normal metabolism. By comparison, the abnormal group had higher LPR (1609 ± 3691 vs. 15.5 ± 6.8, P < 0.001), higher glutamate (157 ± 84 vs. 1.8 ± 1.4 μM, P < 0.001), and lower glucose (0.27 ± 0.35 vs. 1.8 ± 1.1 mmol/l, P < 0.001). The abnormal group demonstrated 13 unique proteins as compared with the normal group in the microdialysate. These proteins consisted of cytoarchitectural proteins, as well as blood breakdown proteins, and a few mitochondrial proteins. A unique as yet to be characterized peptide was found at m/z (mass/charge) 4733.5, which may represent a novel biomarker of metabolic distress. Conclusion Metabolic distress after TBI is associated with a differential proteome that indicates cellular destruction during the acute phase of illness. This suggests that metabolic distress has immediate cellular consequences after TBI.

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Section: Discussionmentioning

confidence: 99%

Metabolic Crisis After Traumatic Brain Injury is Associated with a Novel Microdialysis Proteome

et al. 2010

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“…Only samples collected after this equilibration period were investigated. At the end of each 1 h collection period, the microdialysate of the extracellular fluid was immediately analysed for lactate and pyruvate with the bedside CMA 600 Analyser (CMA Microdialysis) using an enzymatic colourimetric technique ( Afinowi et al ., 2009 ). For quality control analysis, artificial CSF samples were analysed on a calibrated YSI 2003 STAT Plus Glucose and Lactate Analyser (YSI Inc., Yellow Springs, Ohio, USA) and compared with the values derived by the CMA 600 Analyser.…”

Section: Methodsmentioning

confidence: 99%

“…Recovery experiments were carried out as previously described ( Afinowi et al ., 2009 ). Large volume (100 ml) CSF samples ( n = 12) were used as source solutions.…”

Section: Methodsmentioning

confidence: 99%

In vivo monitoring of neuronal loss in traumatic brain injury: a microdialysis study

Petzold

Tisdall

Girbes

et al. 2011

Brain

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Traumatic brain injury causes diffuse axonal injury and loss of cortical neurons. These features are well recognized histologically, but their in vivo monitoring remains challenging. In vivo cortical microdialysis samples the extracellular fluid adjacent to neurons and axons. Here, we describe a novel neuronal proteolytic pathway and demonstrate the exclusive neuro-axonal expression of Pavlov’s enterokinase. Enterokinase is membrane bound and cleaves the neurofilament heavy chain at positions 476 and 986. Using a 100 kDa microdialysis cut-off membrane the two proteolytic breakdown products, extracellular fluid neurofilament heavy chains NfH476−986 and NfH476−1026, can be quantified with a relative recovery of 20%. In a prospective clinical in vivo study, we included 10 patients with traumatic brain injury with a median Glasgow Coma Score of 9, providing 640 cortical extracellular fluid samples for longitudinal data analysis. Following high-velocity impact traumatic brain injury, microdialysate extracellular fluid neurofilament heavy chain levels were significantly higher (6.18 ± 2.94 ng/ml) and detectable for longer (>4 days) compared with traumatic brain injury secondary to falls (0.84 ± 1.77 ng/ml, <2 days). During the initial 16 h following traumatic brain injury, strong correlations were found between extracellular fluid neurofilament heavy chain levels and physiological parameters (systemic blood pressure, anaerobic cerebral metabolism, excessive brain tissue oxygenation, elevated brain temperature). Finally, extracellular fluid neurofilament heavy chain levels were of prognostic value, predicting mortality with an odds ratio of 7.68 (confidence interval 2.15–27.46, P = 0.001). In conclusion, this study describes the discovery of Pavlov’s enterokinase in the human brain, a novel neuronal proteolytic pathway that gives rise to specific protein biomarkers (NfH476−986 and NfH476−1026) applicable to in vivo monitoring of diffuse axonal injury and neuronal loss in traumatic brain injury.

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“…It consists of a thin semi permeable catheter, mimicking a blood vessel, which is inserted in the tissue. The catheter is infused with physiological saline (the perfusate) by a mechanical pump and by diffusion, down a concentration gradient, and collects the substances that pass through the catheter membrane [34][35][36].…”

Section: Microdialysismentioning

confidence: 99%

The Dynamic Computer Workstation—A Pilot Study of Clinical and Biochemical Investigation during Work at Static Respectively Mobile Keyboards

Ghafouri

Wåhlén

Wentzel-Olausson

et al. 2021

IJERPH

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A large and increasing number of the work force in the population spend their work hours at the keyboard. There is evidence that repetitive high levels of static work, or extreme working postures involving the neck–shoulder muscles are an increased risk for chronic neck–shoulder pain. The aim of this study was to investigate the effect of dynamic computer working (DCW), using a mobile application to the desk surface, on pain characteristics and biomarkers in office workers. We included 10 female subjects. All subjects answered questionnaires about general health, pain intensity and characteristics. The pressure pain threshold (PPT), neck range and motion, neck and shoulder strength were measured. Microdialysis was conducted in trapezius muscle. Measurements were performed before and 4 weeks after DCW. Multivariate analysis, orthogonal partial least square discriminate analysis (OPLS-DA) and univariate analysis paired test, Wilcoxon, was performed. There was significant improvement in reported neck pain, quality of life, and psychological distress after 4 weeks DCW. The PPT and strength in neck and shoulder were significantly increased after DCW. A significant OPLS-DA model showed clear separation between the samples collected before and after 4 weeks DCW. In conclusion, these results show that keyboard work at a movable desk application might decrease the risk of repetitive strain injuries in the neck and shoulder muscles.

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Improving the recovery of S100B protein in cerebral microdialysis: Implications for multimodal monitoring in neurocritical care

Cited by 16 publications

References 34 publications

Metabolic Crisis After Traumatic Brain Injury is Associated with a Novel Microdialysis Proteome

Metabolic Crisis After Traumatic Brain Injury is Associated with a Novel Microdialysis Proteome

In vivo monitoring of neuronal loss in traumatic brain injury: a microdialysis study

The Dynamic Computer Workstation—A Pilot Study of Clinical and Biochemical Investigation during Work at Static Respectively Mobile Keyboards

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