Improved Quantification of Prostaglandins in Biological Samples by Optimizing Simultaneously the Relationship Eicosanoid/Internal-Standard and Using Liquid Chromatography Tandem Mass Spectrometry

Although a wide variety of articles on quantification of eicosanoids by using internal standards are published every year, little has been done on how much internal standard should be added. This article demonstrates that the application of experimental design enables estimating the interaction eicosanoid/internal-standard and to select confidently an optimal amount of internal standard and a response factor (RF) for the analysis of eicosanoids in a high number of samples, where the amount of sample is limited and the unknown levels of eicosanoids are spanned in a wide range of concentrations. The results revealed that the interaction eicosanoid/internal-standard is an important factor that affects the validity of the RF and subsequently the accuracy of the analysis

Improved Quantification of Prostaglandins in Biological Samples by Optimizing Simultaneously the Relationship Eicosanoid/Internal-Standard and Using Liquid Chromatography Tandem Mass Spectrometry

Although a wide variety of articles on quantification of eicosanoids by using internal standards are published every year, little has been done on how much internal standard should be added. This article demonstrates that the application of experimental design enables estimating the interaction eicosanoid/internal-standard and to select confidently an optimal amount of internal standard and a response factor (RF) for the analysis of eicosanoids in a high number of samples, where the amount of sample is limited and the unknown levels of eicosanoids are spanned in a wide range of concentrations. The results revealed that the interaction eicosanoid/internal-standard is an important factor that affects the validity of the RF and subsequently the accuracy of the analysis.acceptedVersio

Chemometric Approaches in Calibration Experiments of Trilinolenoylglycerol by Liquid Chromatography Ion-Trap Mass Spectrometry

The article presents a comprehensive account of the application of chemometric approaches to determine the factors that influence the tri-α-linolenoylglycerol (TALG) ammoniated adduct signal m/z 890.6 in an ion-trap mass spectrometer coupled to a liquid chromatograph and the estimation of different sources of errors involved in TALG calibration experiments. It was found that by using experimental design, the influence of the nebulizer pressure on the analytical signal is less pronounced than the influence of the drying gas flow and the chromatographic flow rate. The results revealed that without using tandem mass or atmospheric pressure chemical ionization, it is possible to fragment the TALG backbone and obtain the free α-linolenic acid by varying the drying gas flow and using an electrospray interface. The error decomposition approach revealed that the preparation error was 26 times higher than the instrumental error

Monitoring Program for Pharmaceuticals, illegal substances and contaminants in farmed fish - Annual report for 2019

This report summarises the monitoring data collected in 2019 on the status of illegal substances, pharmaceuticals and contaminants in Norwegian farmed fish. A total of 13 725 fish were collected. Samples examined for illegal compounds would be collected at all stages of farming and are representative of farmed fish under production. The samples were analysed for substances with anabolic effects or unauthorized veterinary drugs. No residues of illegal compounds were detected. Samples tested for approved veterinary drugs and contaminants were collected at processing plants and are representative of Norwegian farmed fish ready for human consumption. Residues of anti-sea-lice agents were found in five samples, the levels present were below the Maximum Residue Limit (MRL) for all samples. Other veterinary drugs, like antibiotics or drugs used against internal parasites were not found. No environmental contaminants were found above the EU maximum levels.publishedVersio

Refined mackerel oil increases hepatic lipid accumulation and reduces choline and choline-containing metabolites in the liver tissue in mice fed a Western diet

In this study, we aimed to evaluate the impact of consuming refined mackerel oil (MO) from rest raw material on hepatic fat accumulation, glucose tolerance, and metabolomic changes in the liver from male C57BL/6N mice. The mice were fed either a Western diet (WD) or a chow diet, with 30 g or 60 g MO per kg of diet (3% or 6%) for 13 weeks. Body weight, energy intake, and feed efficiency were monitored throughout the experiment. A glucose tolerance test was conducted after 11 weeks, and metabolomic analyses of the liver were performed at termination.publishedVersio

Monitoring program for pharmaceuticals, illegal substances, and contaminants in farmed fish - Annual report for 2018

This report summarises the monitoring data collected in 2018 on the status of illegal substances, pharmaceuticals and contaminants in Norwegian farmed fish. A total of 13 920 fish were collected. Samples examined for illegal compounds could be collected at all stages of farming and are representative of farmed fish under production. The samples were analysed for substances with anabolic effects or unauthorized substances. No residues of illegal compounds were detected. Samples tested for approved veterinary drugs and contaminants were collected at processing plants, and are representative of Norwegian farmed fish ready for human consumption. Residues of anti sea lice agents were found in four samples, the levels present were below the Maximum Residue Limit (MRL) for all samples. Other veterinary drugs, like antibiotics or drugs used against internal parasites were not found. No environmental contaminants were found above the EU maximum limits.publishedVersio

Subjective food hypersensitivity: assessment of enterochromaffin cell markers in blood and gut lavage fluid

Background: Food hypersensitivity is commonly suspected, but seldom verified. Patients with subjective food hypersensitivity suffer from both intestinal and extraintestinal health complaints. Abnormalities of the enterochromaffin cells may play a role in the pathogenesis. The aim of this study was to investigate enterochromaffin cell function in patients with subjective food hypersensitivity by measuring serum chromogranin A (CgA) and 5-hydroxytryptamine (5-HT, serotonin) in gut lavage fluid. Methods: Sixty-nine patients with subjective food hypersensitivity were examined. Twenty-three patients with inflammatory bowel disease and 35 healthy volunteers were included as comparison groups. CgA was measured in serum by enzyme-linked immunosorbent assay. Gut lavage fluid was obtained by administering 2 L of polyethylene glycol solution intraduodenally. The first clear fluid passed per rectum was collected and 5-HT was analyzed by liquid chromatography tandem mass spectrometry. Results: Serum levels of CgA were significantly lower in patients with subjective food hypersensitivity than in healthy controls (P 0.04). No differences were found in 5-HT levels in gut lavage fluid between patients with subjective food hypersensitivity and the control groups. There was no correlation between serum CgA and gut lavage 5-HT. Conclusion: Decreased blood levels of CgA suggest neuroendocrine alterations in patients with subjective food hypersensitivity. However, 5-HT levels in gut lavage fluid were normal

Plasma Fatty Acid Ratios Affect Blood Gene Expression Profiles - A Cross-Sectional Study of the Norwegian Women and Cancer Post-Genome Cohort

This paper is part of Karina Standahl Olsen's doctoral thesis, available in Munin at http://hdl.handle.net/10037/5442High blood concentrations of n-6 fatty acids (FAs) relative to n-3 FAs may lead to a “physiological switch” towards permanent low-grade inflammation, potentially influencing the onset of cardiovascular and inflammatory diseases, as well as cancer. To explore the potential effects of FA ratios prior to disease onset, we measured blood gene expression profiles and plasma FA ratios (linoleic acid/alpha-linolenic acid, LA/ALA; arachidonic acid/eicosapentaenoic acid, AA/EPA; and total n-6/n-3) in a cross-section of middle-aged Norwegian women (n = 227). After arranging samples from the highest values to the lowest for all three FA ratios (LA/ALA, AA/EPA and total n-6/n-3), the highest and lowest deciles of samples were compared. Differences in gene expression profiles were assessed by single-gene and pathway-level analyses. The LA/ALA ratio had the largest impact on gene expression profiles, with 135 differentially expressed genes, followed by the total n-6/n-3 ratio (125 genes) and the AA/EPA ratio (72 genes). All FA ratios were associated with genes related to immune processes, with a tendency for increased pro-inflammatory signaling in the highest FA ratio deciles. Lipid metabolism related to peroxisome proliferator-activated receptor γ (PPARγ) signaling was modified, with possible implications for foam cell formation and development of cardiovascular diseases. We identified higher expression levels of several autophagy marker genes, mainly in the lowest LA/ALA decile. This finding may point to the regulation of autophagy as a novel aspect of FA biology which warrants further study. Lastly, all FA ratios were associated with gene sets that included targets of specific microRNAs, and gene sets containing common promoter motifs that did not match any known transcription factors. We conclude that plasma FA ratios are associated with differences in blood gene expression profiles in this free-living population, and that affected genes and pathways may influence the onset and progression of disease

Overvåkingsprogram for legemidler, ulovlige stoffer og forurensende stoffer i oppdrettsfisk

This report summarises the monitoring data collected in 2017 on the status of illegal substances, pharmaceuticals and contaminants in Norwegian farmed fish. A total of 13 640 fish were collected, of these almost 40% were analysed for illegal compounds, approximately 35% were analysed for veterinary drugs, and about 25% were examined for contaminants. Official inspectors from the Norwegian Food Safety Authority performed the sampling. Samples examined for illegal compounds could be collected at all stages of farming and are representative of farmed fish under production. The samples were analysed for substances with anabolic effects or unauthorized substances. No residues of illegal compounds were detected. Samples tested for approved veterinary drugs were collected at processing plants, and are representative of Norwegian farmed fish ready for human consumption. Residues of three anti sea lice agents; Emamectin, cypermethrin or diflubenzuron, were found in 16 samples. The levels present were below the Maximum Residue Limit (MRL) for all samples. Other veterinary drugs, like antibiotics or drugs used against internal parasites, were not found. Samples analysed for contaminants were collected at processing plants, and are representative of Norwegian farmed fish ready for the human consumption. The samples were analysed for dioxins, dioxin like PCBs (dl-PCBs), indicator PCB (PCB-6), pesticides, metals, PAH, PFC or/and BFR. No environmental contaminants were found above the EU maximum limits. The declining trend that previously has been observed for several of the contaminants seems to have stopped and today’s level are similar to the results from the last years.publishedVersio

A comprehensive assessment of fish and other seafood in the Norwegian diet.

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