80 research outputs found
What is in the fish? Collaborative trial in suspect and non-target screening of organic micropollutants using LC- and GC-HRMS
A collaborative trial involving 16 participants from nine European countries was conducted within the NORMAN network in efforts to harmonise suspect and non-target screening of environmental contaminants in whole fish samples of bream (Abramis brama). Participants were provided with freeze-dried, homogenised fish samples from a contaminated and a reference site, extracts (spiked and non-spiked) and reference sample preparation protocols for liquid chromatography (LC) and gas chromatography (GC) coupled to high resolution mass spectrometry (HRMS). Participants extracted fish samples using their in-house sample preparation method and/or the protocol provided. Participants correctly identified 9â69 % of spiked compounds using LC-HRMS and 20â60 % of spiked compounds using GC-HRMS. From the contaminated site, suspect screening with participantsâ own suspect lists led to putative identification of on average ~145 and ~20 unique features per participant using LC-HRMS and GC-HRMS, respectively, while non-target screening identified on average ~42 and ~56 unique features per participant using LC-HRMS and GC-HRMS, respectively. Within the same sub-group of sample preparation method, only a few features were identified by at least two participants in suspect screening (16 features using LC-HRMS, 0 features using GC-HRMS) and non-target screening (0 features using LC-HRMS, 2 features using GCHRMS). The compounds identified had log octanol/water partition coefficient (KOW) values from â 9.9 to 16 and mass-to-charge ratios (m/z) of 68 to 761 (LC-HRMS and GC-HRMS). A significant linear trend was found between log KOW and m/z for the GC-HRMS data. Overall, these findings indicate that differences in screening results are mainly due to the data analysis workflows used by different participants. Further work is needed to harmonise the results obtained when applying suspect and non-target screening approaches to environmental biota samples
Balance between survivin, a key member of the apoptosis inhibitor family, and its specific antibodies determines erosivity in rheumatoid arthritis
Rheumatoid arthritis (RA) is a highly heterogeneous disease with respect to its joint destructivity. The reasons underlying this heterogeneity are unknown. Deficient apoptosis in rheumatoid synovial tissue has been recently demonstrated. We have therefore decided to study the synovial expression of survivin, a key member of the apoptosis inhibitor family. The levels of survivin and antibodies against survivin were assessed by an ELISA in matched blood and synovial fluid samples collected from 131 RA patients. Results were related to joint erosivity at the time of sampling. Monocytes were transfected with survivin anti-sense oligonucleotides and were assessed for their ability to produce inflammatory cytokines. Survivin levels were significantly higher in patients with destructive disease as compared with in RA patients displaying a non-erosive disease. High survivin levels were an independent prognostic parameter for erosive RA. In contrast, high levels of antibodies against survivin were found in patients with non-erosive RA, and were negatively related to erosivity. Survivin levels in RA patients were influenced by treatment, being significantly lower among patients treated with disease-modifying anti-rheumatic drugs. Specific suppression of survivin mRNA resulted in downregulation of IL-6 production. We conclude that survivin determines the erosive course of RA, whereas survivin antibodies lead to a less aggressive course of the disease. These findings together with decreased survivin levels upon disease-modifying anti-rheumatic drug treatment, and the downregulation of inflammatory response using survivin anti-sense oligonucleotides, suggest that extracellular survivin expression mediates the erosive course of joint disease whereas autoimmune responses to the same molecule, manifested as survivin targeting antibodies, mediate protection
The Shepherds' Tale : A Genome-Wide Study across 9 Dog Breeds Implicates Two Loci in the Regulation of Fructosamine Serum Concentration in Belgian Shepherds
Diabetes mellitus is a serious health problem in both dogs and humans. Certain dog breeds show high prevalence of the disease, whereas other breeds are at low risk. Fructosamine and glycated haemoglobin (HbA1c) are two major biomarkers of glycaemia, where serum concentrations reflect glucose turnover over the past few weeks to months. In this study, we searched for genetic factors influencing variation in serum fructosamine concentration in healthy dogs using data from nine dog breeds. Considering all breeds together, we did not find any genome-wide significant associations to fructosamine serum concentration. However, by performing breed-specific analyses we revealed an association on chromosome 3 (rho(corrected) approximate to 1:68 x 10(-6)) in Belgian shepherd dogs of the Malinois subtype. The associated region and its close neighbourhood harbours interesting candidate genes such as LETM1 and GAPDH that are important in glucose metabolism and have previously been implicated in the aetiology of diabetes mellitus. To further explore the genetics of this breed specificity, we screened the genome for reduced heterozygosity stretches private to the Belgian shepherd breed. This revealed a region with reduced heterozygosity that shows a statistically significant interaction (rho = 0.025) with the association region on chromosome 3. This region also harbours some interesting candidate genes and regulatory regions but the exact mechanisms underlying the interaction are still unknown. Nevertheless, this finding provides a plausible explanation for breed-specific genetic effects for complex traits in dogs. Shepherd breeds are at low risk of developing diabetes mellitus. The findings in Belgian shepherds could be connected to a protective mechanism against the disease. Further insight into the regulation of glucose metabolism could improve diagnostic and therapeutic methods for diabetes mellitus.Peer reviewe
Interstellar Grains -- The 75th Anniversary
The year of 2005 marks the 75th anniversary since Trumpler (1930) provided
the first definitive proof of interstellar grains by demonstrating the
existence of general absorption and reddening of starlight in the galactic
plane. This article reviews our progressive understanding of the nature of
interstellar dust.Comment: invited review article for the "Light, Dust and Chemical Evolution"
conference (Gerace, Italy, 26--30 September 2004), edited by F. Borghese and
R. Saija, 2005, in pres
Role of environmental toxins in chronic experimental arthrithis - in search for anti-inflammatory pathways of ethanol and nicotine
Rheumatoid arthritis (RA) is a common systemic autoimmune disorder and a debilitating disease
affecting 1% of the world population. The etiology of RA is an unresolved issue. Environmental factors
such as alcohol intake and cigarette smoke have been described as contributing to the pathogenesis of RA.
These assumptions are based on epidemiological studies, while experimental proof on this issue is limited.
This thesis studies the effect of common environmental toxins on experimental arthritis induced by
collagen type II (collagen-induced arthritis, CIA), an established murine model closely resembling human
RA. We propose biological mechanisms behind the anti-inflammatory properties of environmental
stimuli such as ethanol and nicotine, and provide new insights into the pathogenesis of RA.
Paper I shows that a continuous intake of ethanol delays the onset and halts the progression of CIA in
mice. This anti-arthritic effect is mediated by increased testosterone secretion leading to (i) decreased
activation of transcription factor NF-ÎșB, (ii) down-regulation of pro-inflammatory cyto- and chemokines
and (iii) down-regulation of leukocyte migration into the joints.
Paper II studies the effect of cigarette smoking and nicotine exposure in CIA mice. Results show that mice
exposed to cigarette smoke develop a significantly milder arthritis with reduced destruction of joints.
Nicotine-exposed mice show a tendency to decreased inflammation. Notably, exposure to cigarette smoke
reduces antigen response and decreases the level of CII-specific antibodies.
Paper III handles intervention with ethanol-sensitive glutamate receptors. CIA mice subjected to the
NMDA receptor antagonist memantine show significantly decreased severity of arthritis and reduced
destructive disease. We show that memantine up-regulates transcription factor Foxp3 and enhances
formation of CD4+CD25+Foxp3+ regulatory T cells, which may be a potential reason for the anti-arthritic
properties of the NMDA receptor blockade.
In conclusion, our results provide new insights into the anti-inflammatory properties of environmental
toxins such as ethanol and nicotine, as well as of blockade of the ethanol-sensitive NMDA receptor. Our
findings from experimental studies need further validation in the population of RA patients
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