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Sökning: WFRF:(Kolmert Johan) > Engelska

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1.
  • Kolmert, Johan, et al. (författare)
  • Urinary Leukotriene E-4 and Prostaglandin D-2 Metabolites Increase in Adult and Childhood Severe Asthma Characterized by Type 2 Inflammation A Clinical Observational Study
  • 2021
  • Ingår i: American Journal of Respiratory and Critical Care Medicine. - NEW YORK, USA : AMER THORACIC SOC. - 1073-449X .- 1535-4970. ; 203:1, s. 37-53
  • Tidskriftsartikel (refereegranskat)abstract
    • Rationale: New approaches are needed to guide personalized treatment of asthma. Objectives: To test if urinary eicosanoid metabolites can direct asthma phenotyping. Methods: Urinary metabolites of prostaglandins (PGs), cysteinyl leukotrienes (CysLTs), and isoprostanes were quantified in the U-BIOPRED (Unbiased Biomarkers for the Prediction of Respiratory Diseases Outcomes) study including 86 adults with mild-to-moderate asthma (MMA), 411 with severe asthma (SA), and 100 healthy control participants. Validation was performed internally in 302 participants with SA followed up after 12-18 months and externally in 95 adolescents with asthma. Measurement and Main Results: Metabolite concentrations in healthy control participants were unrelated to age, body mass index, and sex, except for the PGE(2) pathway. Eicosanoid concentrations were generally greater in participants with MMA relative to healthy control participants, with further elevations in participants with SA. However, PGE(2) metabolite concentrations were either the same or lower in male nonsmokers with asthma than in healthy control participants. Metabolite concentrations were unchanged in those with asthma who adhered to oral corticosteroid treatment as documented by urinary prednisolone detection, whereas those with SA treated with omalizumab had lower concentrations of LTE4 and the PGD(2) metabolite 2,3-dinor-11 beta-PGF(2 alpha). High concentrations of LTE4 and PGD(2) metabolites were associated with lower lung function and increased amounts of exhaled nitric oxide and eosinophil markers in blood, sputum, and urine in U-BIOARED participants and in adolescents with asthma. These type 2 (T2) asthma associations were reproduced in the follow-up visit of the U-BIOPRED study and were found to be as sensitive to detect T2 inflammation as the established biomarkers. Conclusions: Monitoring of urinary eicosanoids can identify T2 asthma and introduces a new noninvasive approach for molecular phenotyping of adult and adolescent asthma.
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2.
  • Stolt, Ragnar, et al. (författare)
  • Second-Order Peak Detection for Multicomponent High-Resolution LC/MS Data
  • 2006
  • Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 78:4, s. 975-83
  • Tidskriftsartikel (refereegranskat)abstract
    • The first step when analyzing multicomponent LC/MS data from complex samples such as biofluid metabolic profiles is to separate the data into information and noise via, for example, peak detection. Due to the complex nature of this type of data, with problems such as alternating backgrounds and differing peak shapes, this can be a very complex task. This paper presents and evaluates a two-dimensional peak detection algorithm based on raw vector-represented LC/MS data. The algorithm exploits the fact that in high-resolution centroid data chromatographic peaks emerge flanked with data voids in the corresponding mass axis. According to the proposed method, only 4‰ of the total amount of data from a urine sample is defined as chromatographic peaks; however, 94% of the raw data variance is captured within these peaks. Compared to bucketed data, results show that essentially the same features that an experienced analyst would define as peaks can automatically be extracted with a minimum of noise and background. The method is simple and requires a priori knowledge of only the minimum chromatographic peak widtha system-dependent parameter that is easily assessed. Additional meta parameters are estimated from the data themselves. The result is well-defined chromatographic peaks that are consistently arranged in a matrix at their corresponding m/z values. In the context of automated analysis, the method thus provides an alternative to the traditional approach of bucketing the data followed by denoising and/or one-dimensional peak detection. The software implementation of the proposed algorithm is available at http://www.anchem.su.se/peakd as compiled code for Matlab.
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3.
  • Badi, Yusef Eamon, et al. (författare)
  • Mapping atopic dermatitis and anti–IL-22 response signatures to type 2–low severe neutrophilic asthma
  • 2022
  • Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier. - 0091-6749 .- 1097-6825. ; 149:1, s. 89-101
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Transcriptomic changes in patients who respond clinically to biological therapies may identify responses in other tissues or diseases.Objective: We sought to determine whether a disease signature identified in atopic dermatitis (AD) is seen in adults with severe asthma and whether a transcriptomic signature for patients with AD who respond clinically to anti–IL-22 (fezakinumab [FZ]) is enriched in severe asthma.Methods: An AD disease signature was obtained from analysis of differentially expressed genes between AD lesional and nonlesional skin biopsies. Differentially expressed genes from lesional skin from therapeutic superresponders before and after 12 weeks of FZ treatment defined the FZ-response signature. Gene set variation analysis was used to produce enrichment scores of AD and FZ-response signatures in the Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes asthma cohort.Results: The AD disease signature (112 upregulated genes) encompassing inflammatory, T-cell, TH2, and TH17/TH22 pathways was enriched in the blood and sputum of patients with asthma with increasing severity. Patients with asthma with sputum neutrophilia and mixed granulocyte phenotypes were the most enriched (P <.05). The FZ-response signature (296 downregulated genes) was enriched in asthmatic blood (P <.05) and particularly in neutrophilic and mixed granulocytic sputum (P <.05). These data were confirmed in sputum of the Airway Disease Endotyping for Personalized Therapeutics cohort. IL-22 mRNA across tissues did not correlate with FZ-response enrichment scores, but this response signature correlated with TH22/IL-22 pathways.Conclusions: The FZ-response signature in AD identifies severe neutrophilic asthmatic patients as potential responders to FZ therapy. This approach will help identify patients for future asthma clinical trials of drugs used successfully in other chronic diseases.
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4.
  • Bowden, John A., et al. (författare)
  • Harmonizing lipidomics : NIST interlaboratory comparison exercise for lipidomics using SRM 1950-Metabolites in Frozen Human Plasma
  • 2017
  • Ingår i: Journal of Lipid Research. - 0022-2275 .- 1539-7262. ; 58:12, s. 2275-2288
  • Tidskriftsartikel (refereegranskat)abstract
    • As the lipidomics field continues to advance, self-evaluation within the community is critical. Here, we performed an interlaboratory comparison exercise for lipidomics using Standard Reference Material (SRM) 1950-Metabolites in Frozen Human Plasma, a commercially available reference material. The interlaboratory study comprised 31 diverse laboratories, with each laboratory using a different lipidomics workflow. A total of 1,527 unique lipids were measured across all laboratories and consensus location estimates and associated uncertainties were determined for 339 of these lipids measured at the sum composition level by five or more participating laboratories. These evaluated lipids detected in SRM 1950 serve as community-wide benchmarks for intra-and interlaboratory quality control and method validation. These analyses were performed using nonstandardized laboratory-independent workflows. The consensus locations were also compared with a previous examination of SRM 1950 by the LIPID MAPS consortium.jlr While the central theme of the interlaboratory study was to provide values to help harmonize lipids, lipid mediators, and precursor measurements across the community, it was also initiated to stimulate a discussion regarding areas in need of improvement.
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5.
  • Emma, Rosalia, et al. (författare)
  • Enhanced oxidative stress in smoking and ex-smoking severe asthma in the U-BIOPRED cohort
  • 2018
  • Ingår i: PLOS ONE. - : Public Library Science. - 1932-6203. ; 13:9
  • Tidskriftsartikel (refereegranskat)abstract
    • Oxidative stress is believed to be a major driver of inflammation in smoking asthmatics. The U-BIOPRED project recruited a cohort of Severe Asthma smokers/ex-smokers (SAs/ex) and non-smokers (SAn) with extensive clinical and biomarker information enabling characterization of these subjects. We investigated oxidative stress in severe asthma subjects by analysing urinary 8-iso-PGF(2 alpha) and the mRNA-expression of the main pro-oxidant (NOX2; NOSs) and anti-oxidant (SODs; CAT; GPX1) enzymes in the airways of SAs/ex and SAn. All the severe asthma U-BIOPRED subjects were further divided into current smokers with severe asthma (CSA), ex-smokers with severe asthma (ESA) and non-smokers with severe asthma (NSA) to deepen the effect of active smoking. Clinical data, urine and sputum were obtained from severe asthma subjects. A bronchoscopy to obtain bronchial biopsy and brushing was performed in a subset of subjects. The main clinical data were analysed for each subset of subjects (urine-8-iso-PGF(2 alpha); IS-transcriptomics; BB-transcriptomics; BBrtranscriptomics). Urinary 8-iso-PGF(2 alpha) was quantified using mass spectrometry. Sputum, bronchial biopsy and bronchial brushing were processed for mRNA expression microarray analysis. Urinary 8-iso-PGF(2 alpha) was increased in SAs/ex, median (IQR) = 31.7 (24.5 +/- 44.7) ng/mmol creatinine, compared to SAn, median (IQR) = 26.6 (19.6 +/- 36.6) ng/mmol creatinine (p< 0.001), and in CSA, median (IQR) = 34.25 (24.4 +/- 47.7), vs. ESA, median (IQR) = 29.4 (22.3 +/- 40.5), and NSA, median (IQR) = 26.5 (19.6 +/- 16.6) ng/mmol creatinine (p = 0.004). Sputum mRNA expression of NOX2 was increased in SAs/ex compared to SAn (probe sets 203922_PM_s_at fold-change = 1.05 p = 0.006; 203923_PM_s_at fold-change = 1.06, p = 0.003; 233538_PM_s_at fold-change = 1.06, p = 0.014). The mRNA expression of antioxidant enzymes were similar between the two severe asthma cohorts in all airway samples. NOS2 mRNA expression was decreased in bronchial brushing of SAs/ex compared to SAn (fold-change = -1.10; p = 0.029). NOS2 mRNA expression in bronchial brushing correlated with FeNO (Kendal's Tau = 0.535; p< 0.001). From clinical and inflammatory analysis, FeNO was lower in CSA than in ESA in all the analysed subject subsets (p< 0.01) indicating an effect of active smoking. Results about FeNO suggest its clinical limitation, as inflammation biomarker, in severe asthma active smokers. These data provide evidence of greater systemic oxidative stress in severe asthma smokers as reflected by a significant changes of NOX2 mRNA expression in the airways, together with elevated urinary 8-iso-PGF(2 alpha) in the smokers/ex-smokers group.
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6.
  • Johnsson, Anna-Karin, et al. (författare)
  • COX-1 dependent biosynthesis of 15-hydroxyeicosatetraenoic acid in human mast cells
  • 2021
  • Ingår i: Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids. - : Elsevier. - 1388-1981 .- 1879-2618. ; 1866:5
  • Tidskriftsartikel (refereegranskat)abstract
    • 15-hydroxyeicosatetraenoic acid (15-HETE) is an arachidonic acid derived lipid mediator which can originate both from 15-lipoxygenase (15-LOX) activity and cyclooxygenase (COX) activity. The enzymatic source determines the enantiomeric profile of the 15-HETE formed. 15-HETE is the most abundant arachidonic acid metabolite in the human lung and has been suggested to influence the pathophysiology of asthma. Mast cells are central effectors in asthma, but there are contradictory reports on whether 15-HETE originates from 15-LOX or COX in human mast cells. This prompted the current study where the pathway of 15-HETE biosynthesis was examined in three human mast cell models; the cell line LAD2, cord blood derived mast cells (CBMC) and tissue isolated human lung mast cells (HLMC). Levels and enantiomeric profiles of 15-HETE and levels of the downstream metabolite 15-KETE, were analyzed by UPLC-MS/MS after stimulation with anti-IgE or calcium ionophore A23187 in the presence and absence of inhibitors of COX isoenzymes. We found that 15-HETE was produced by COX-1 in human mast cells under these experimental conditions. Unexpectedly, chiral analysis showed that the 15(R) isomer was predominant and gradually accumulated, whereas the 15(S) isomer was metabolized by the 15hydroxyprostaglandin dehydrogenase. We conclude that during physiological conditions, i.e., without addition of exogenous arachidonic acid, both enantiomers of 15-HETE are produced by COX-1 in human mast cells but that the 15(S) isomer is selectively depleted by undergoing further metabolism. The study highlights that 15-HETE cannot be used as an indicator of 15-LOX activity for cellular studies, unless chirality and sensitivity to pharmacologic inhibition is determined.
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7.
  • Johnsson, Anna-Karin, et al. (författare)
  • Selective inhibition of prostaglandin D-2 biosynthesis in human mast cells to overcome need for multiple receptor antagonists : Biochemical consequences
  • 2021
  • Ingår i: Clinical and Experimental Allergy. - : John Wiley & Sons. - 0954-7894 .- 1365-2222. ; 51:4, s. 594-603
  • Tidskriftsartikel (refereegranskat)abstract
    • Background The major mast cell prostanoid PGD(2) is targeted for therapy of asthma and other diseases, because the biological actions include bronchoconstriction, vasodilation and regulation of immune cells mediated by three different receptors. It is not known if the alternative to selectively inhibit the biosynthesis of PGD(2) affects release of other prostanoids in human mast cells. Objectives To determine the biochemical consequences of inhibition of the hematopoietic prostaglandin D synthase (hPGDS) PGD(2) in human mast cells. Methods Four human mast cell models, LAD2, cord blood derived mast cells (CBMC), peripheral blood derived mast cells (PBMC) and human lung mast cells (HLMC), were activated by anti-IgE or ionophore A23187. Prostanoids were measured by UPLC-MS/MS. Results All mast cells almost exclusively released PGD(2) when activated by anti-IgE or A23187. The biosynthesis was in all four cell types entirely initiated by COX-1. When pharmacologic inhibition of hPGDS abolished formation of PGD(2), PGE(2) was detected and release of TXA(2) increased. Conversely, when the thromboxane synthase was inhibited, levels of PGD(2) increased. Adding exogenous PGH(2) confirmed predominant conversion to PGD(2) under control conditions, and increased levels of TXB2 and PGE(2) when hPGDS was inhibited. However, PGE(2) was formed by non-enzymatic degradation. Conclusions Inhibition of hPGDS effectively blocks mast cell dependent PGD(2) formation. The inhibition was associated with redirected use of the intermediate PGH(2) and shunting into biosynthesis of TXA(2). However, the levels of TXA(2) did not reach those of PGD(2) in naive cells. It remains to determine if this diversion occurs in vivo and has clinical relevance.
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8.
  • Kolmert, Johan, et al. (författare)
  • A quantitative LC/MS method targeting urinary 1-methyl-4-imidazoleacetic acid for safety monitoring of the global histamine turnover in clinical studies
  • 2014
  • Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 406:6, s. 1751-1762
  • Tidskriftsartikel (refereegranskat)abstract
    • Anaphylaxis is a potentially life-threatening condition triggered mainly by the release of inflammatory mediators, notably histamine. In pharmaceutical research, drug discovery, and clinical evaluation, it may be necessary to accurately assess the potential of a compound, event, or disorder to promote the release of histamine. In contrast to the measurement of plasma histamine, determination of the stable metabolite 1-methyl-4-imidazoleacetic acid (tele-MIAA) in urine provides a noninvasive and more reliable methodology to monitor histamine release. This study presents a repeatable high-performance liquid chromatography coupled to electrospray mass spectrometry (LC-ESI-MS) method where tele-MIAA is baseline separated from its structural isomer 1-methyl-5-imidazoleacetic acid (pi-MIAA) and an unknown in human urine. The ion-pairing chromatography method, in reversed-phase mode, based on 0.5 mM tridecafluoroheptanoic acid demonstrated high repeatability and was applied in a clinical development program that comprised a large number of clinical samples from different cohorts. The inter- and intra-run precision of the method for tele-MIAA were 8.4 and 4.3 %, respectively, at the mean urinary concentration level, while method accuracy was between -16.2 and 8.0 % across the linear concentration range of 22-1,111 ng mL(-1). Overall, method precision was greater than that reported in previously published methods and enabled the identification of gender differences that were independent of age or demography. The median concentration measured in female subjects was 3.0 mu mol mmol(-1) of creatinine, and for male subjects, it was 2.1 mu mol mmol(-1) of creatinine. The results demonstrate that the method provides unprecedented accuracy, precision, and practicality for the measurement of tele-MIAA in large clinical settings.
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9.
  • Kolmert, Johan (författare)
  • Quantification of inflammatory mediators to explore molecular mechanisms and sub-phenotypes of asthma
  • 2018
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • This thesis summarizes a series of studies using liquid chromatography coupled to mass spectrometry methodologies to quantify metabolites of fatty acids (i.e., oxylipins) and histamine in different samples from experimental models and clinical studies with the overall aim to define mechanisms and identify biomarkers for improved sub-phenotyping of asthma. Asthma is characterized by variable airflow obstruction, hyperresponsiveness and chronic inflammation in the airways. The substantial overlap among clinical descriptors has resulted in difficulties to establish diagnosis and predict response to treatment. Instead, a shift in focus towards identifying specific cellular and molecular mechanisms has emerged, aiming to define new treatable traits based on specific cellular and molecular pathways (defined as endotypes). Important pathobiological components involve the release of potent inflammatory mediators, such as histamine, prostaglandins (PGs) and leukotrienes (LTs), that cause bronchoconstriction and airway inflammation. A rapid hydrophilic interaction chromatography method failed to quantify the major histamine metabolite 1,4-methyl-5-imidazoleacetic acid (tele-MIAA) due to ion suppression from inorganic salts present in urine. Ion-pairing chromatography was therefore employed and the resulting increase in precision enabled the detection of higher baseline levels of tele-MIAA in females compared to males (3.0 vs. 2.1 μmol/mmol creatinine, respectively) (Paper I). In addition, levels of tele-MIAA reached up to 30 μmol/mmol creatinine in spot urine samples from mastocytosis patients. Three liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) methods quantified 130 oxylipins and were able to define kinetic release and enzymatic contribution of mast cell-derived mediators to smooth muscle contraction using isolated and intact airways from humans and guinea pigs in vitro. PGD2 levels were elevated 24-hour post anti-IgE stimulation of human bronchus, suggesting a prolonged mast cell activation (Paper II). Furthermore, exposure to house dust mite (HDM) induced strong release of lipoxygenase-derived LTB4, 5,15-DiHETE, 15-HETE and 15-HEDE along with eosinophilic infiltration in a C57BL/6 murine model of asthma. Interestingly, high levels of cysteinyl-leukotrienes (CysLTs) remained unchanged suggesting a different role of CysLTs in mice (Paper III). Urinary profiles of 11 eicosanoid metabolites in 100 healthy control subjects and 497 asthmatics defined normal baseline levels and revealed increased concentration of PGs, LTE4 and isoprostanes with asthma severity. Consensus clustering of 497 asthmatics identified a five-cluster model with distinct clinical characteristics, which included two new phenotypes, U1 and U5, with low levels of thromboxanes and PGs respectively (Paper IV). At the 12 to 18-month longitudinal time point for the 302 subjects with severe asthma, z-scored eicosanoid concentrations retained the five-cluster profile, despite technical and intra-subject variability. In conclusion, the developed bioanalytical methods were applied to define levels of histamine and eicosanoid metabolites in urine from healthy subjects. In addition, release of multiple oxylipins following mast cell-mediated bronchoconstriction and HDM-induced airway inflammation in model systems were explored to relate functions to levels of lipid mediators. For the first time, grouping of asthmatics according to profiles of eicosanoid metabolites in urine was performed and demonstrated sufficient resolution to identify five sub-phenotypes of asthma possessing distinct clinical characteristics. The presented approaches, for both in vitro and in vivo respiratory research, offer an opportunity to progress the development of new treatment options and suggests a panel of PGs, LTE4 and isoprostanes to be further validated as diagnostic markers in patients with asthma.
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