| 1. |
- Martensson, Johan, et al.
(författare)
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Association of plasma neutrophil gelatinase-associated lipocalin (NGAL) with sepsis and acute kidney dysfunction
- 2013
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Ingår i: Biomarkers. - 1354-750X .- 1366-5804. ; 18:4, s. 349-356
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Neutrophil gelatinase-associated lipocalin (NGAL) is secreted by injured kidney cells as well as by activated neutrophils in response to bacterial infections. We assessed the influence of acute renal dysfunction on the association between plasma NGAL and sepsis. Methods: NGAL was measured daily in 138 critically ill patients. Simultaneous recordings of sepsis status and fluctuations in renal function were made. Results: Elevated NGAL was associated with sepsis independent of level of acute renal dysfunction. A cut-off value of 98 ng/mL distinguished sepsis from systemic inflammation with high sensitivity (0.77) and specificity (0.79). Conclusions: Plasma NGAL can help clinicians to identify bacterial infections in critically ill patients.
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| 2. |
- Martensson, Johan, et al.
(författare)
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Immunoassays distinguishing between HNL/NGAL released in urine from kidney epithelial cells and neutrophils
- 2012
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Ingår i: Clinica Chimica Acta. - : Elsevier BV. - 0009-8981 .- 1873-3492. ; 413:19-20, s. 1661-1667
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Tidskriftsartikel (refereegranskat)abstract
- Background: The distinction between monomeric human neutrophil lipocalin/neutrophil gelatinase-associated lipocalin (HNL/NGAL), secreted by injured kidney tubular cells, and dimeric HNL/NGAL, released by activated neutrophils, is important to accurately diagnose acute kidney injury (AKI).Methods: 132 urine samples from 44 intensive care unit (ICU) patients and five urine samples from non-ICU patients with urinary tract infections (UTIs) were analyzed by two monoclonal enzyme-linked immunosorbent assays (ELISA-1 and ELISA-2). The presence of monomeric and/or dimeric HNL/NGAL in each sample was visualized by Western blotting.Results: The ELISA-1 detected both monomeric and dimeric HNL/NGAL whereas the ELISA-2 almost exclusively detected dimeric HNL/NGAL with an area under the receiver-operating characteristics curve (AuROC) of 0.90. The ELISA-1/ELISA-2 ratio detected the monomeric form with an AuROC of 0.92. In 32 AKI patients, dimer-specific EUSA-2 levels decreased pre-AKI whereas the monomer-specific ELISA-1/ELISA-2 ratio gradually increased beyond AKI diagnosis. High EUSA-2 levels and/or low ELISA-1/ELISA-2 ratios detected a predominance of dimeric HNL/NGAL in urine from the patients with tills.Conclusions: In combination, our two ELISAs distinguish monomeric HNL/NGAL, produced by the kidney epithelium, from dimeric HNL/NGAL, released by neutrophils during AKI development, as well as reduce the confounding effect of neutrophil involvement when bacteriuria is present.
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| 3. |
- Martensson, Johan, et al.
(författare)
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Neutrophil gelatinase-associated lipocalin in adult septic patients with and without acute kidney injury
- 2010
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Ingår i: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 36:8, s. 1333-1340
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Tidskriftsartikel (refereegranskat)abstract
- To study the impact of inflammation/sepsis on the concentrations of neutrophil gelatinase-associated lipocalin (NGAL) in plasma and urine in adult intensive care unit (ICU) patients and to estimate the predictive properties of NGAL in plasma and urine for early detection of acute kidney injury (AKI) in patients with septic shock. Sixty-five patients admitted to the general ICU at the Karolinska University Hospital Solna, Sweden, with normal plasma creatinine were assessed for eligibility. Twenty-seven patients with systemic inflammatory response syndrome (SIRS), severe sepsis, or septic shock without AKI and 18 patients with septic shock and concomitant AKI were included in the final analysis. Plasma and urine were analyzed twice daily for plasma NGAL (pNGAL), C-reactive protein (CRP), procalcitonin, myeloperoxidase, plasma cystatin C, plasma creatinine, urine NGAL (uNGAL), urine cystatin C, and urine alpha 1-microglobulin. Of the 45 patients, 40 had elevated peak levels of pNGAL. Peak levels of pNGAL were not significantly different between septic shock patients with and without AKI. Peak levels of uNGAL were below the upper reference limit in all but four patients without AKI. uNGAL was a good predictor (area under ROC 0.86) whereas pNGAL was a poor predictor (area under ROC 0.67) for AKI within the next 12 h in patients with septic shock. pNGAL is raised in patients with SIRS, severe sepsis, and septic shock and should be used with caution as a marker of AKI in ICU patients with septic shock. uNGAL is more useful in predicting AKI as the levels are not elevated in septic patients without AKI.
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| 4. |
- Martensson, Nils, et al.
(författare)
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On the relation between X-ray Photoelectron Spectroscopy and XAFS
- 2013
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Ingår i: 15th International Conference On X-Ray Absorption Fine Structure (XAFS15). - : IOP Publishing.
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Konferensbidrag (refereegranskat)abstract
- XAFS and X-ray Photoelectron Spectroscopy (XPS) are element specific techniques used in a great variety of research fields. The near edge regime of XAFS provides information on the unoccupied electronic states of a system. For the detailed interpretation of the XAFS results, input from XPS is crucial. The combination of the two techniques is also the basis for the so called core-hole clock technique. One of the important aspects of photoelectron spectroscopy is its chemical sensitivity and that one can obtain detailed information about the composition of a sample. We have for a series of carbon based model molecules carefully investigated the relationship between core level photoelectron intensities and stoichiometry. We find strong EXAFS-like modulations of the core ionization cross sections as function of photon energy and that the intensities at high photon energies converge towards values that do not correspond to the stoichiometric ratios. The photoelectron intensities are dependent on the local molecular structure around the ionized atoms. These effects are well described by molecular calculations using multiple scattering theory and by considering the effects due to monopole shake-up and shake-off as well as to intramolecular inelastic scattering processes.
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