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- Cao, Yang, Associate Professor, 1972-, et al.
(författare)
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Efficacy of succimer chelation of mercury at background exposures in toddlers : a randomized trial
- 2011
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Ingår i: The Journal of Pediatrics. - : Elsevier. - 0022-3476 .- 1097-6833. ; 158:3, s. 480-485.e1
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To examine whether succimer, a mercaptan compound known to reduce blood lead concentration in children, reduces blood mercury concentration.STUDY DESIGN: We used samples from a randomized clinical trial of succimer chelation for lead-exposed children. We measured mercury levels in pre-treatment samples from 767 children. We also measured mercury levels in blood samples drawn 1 week after treatment began (n = 768) and in a 20% random sample of the children who received the maximum 3 courses of treatment (n = 67). A bootstrap-based isotonic regression method was used to compare the trend with time in the difference between the adjusted mean mercury concentrations in the succimer group and that in the placebo group.RESULTS: The adjusted mean organic mercury concentration in the succimer group relative to the placebo group fell from 99% at baseline to 82% after 3 courses of treatment (P for trend = .048), but this resulted from the prevention of the age-related increase in the succimer group.CONCLUSION: Succimer chelation for low level organic mercury exposure in children has limited efficacy.
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| 2. |
- Kadiiska, Maria B., et al.
(författare)
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Biomarkers of oxidative stress study VI. Endogenous plasma antioxidants fail as useful biomarkers of endotoxin-induced oxidative stress
- 2015
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Ingår i: Free Radical Biology & Medicine. - : Elsevier BV. - 0891-5849 .- 1873-4596. ; 81, s. 100-106
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Tidskriftsartikel (refereegranskat)abstract
- This is the newest report in a series of publications aiming to identify a blood-based antioxidant biomarker that could serve as an in vivo indicator of oxidative stress. The goal of the study was to test whether acutely exposing Gottingen mini pigs to the endotoxin lipopolysaccharide (LPS) results in a loss of antioxidants from plasma. We set as a criterion that a significant effect should be measured in plasma and seen at both doses and at more than one time point Animals were injected with two doses of LPS at 2.5 and 514/kg iv. Control plasma was collected from each animal before the LPS injection. After the LPS injection, plasma samples were collected at 2, 16, 48, and 72 h. Compared with the controls at the same time point, statistically significant losses were not found for either dose at multiple time points in any of the following potential markers: ascorbic acid, tocopherols (alpha, delta, gamma), ratios of GSH/GSSG and cysteine/cystine, mixed disulfides, and total antioxidant capacity. However, uric acid, total GSH, and total Cys were significantly increased, probably because LPS had a harmful effect on the liver. The leakage of substances from damaged cells into the plasma may have increased plasma antioxidant concentrations, making changes difficult to interpret Although this study used a mini-pig animal model of LPS-induced oxidative stress, it confirmed our previous findings in different rat models that measurement of antioxidants in plasma is not useful for the assessment of oxidative damage in vivo.
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| 3. |
- Khomich, Maryia, et al.
(författare)
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Association between lipid-A-producing oral bacteria of different potency and fractional exhaled nitric oxide in a Norwegian population-based adult cohort
- 2023
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Ingår i: Journal of Translational Medicine. - : BioMed Central (BMC). - 1479-5876 .- 1479-5876. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Lipid A is the primary immunostimulatory part of the lipopolysaccharide (LPS) molecule. The inflammatory response of LPS varies and depends upon the number of acyl chains and phosphate groups in lipid A which is specific for a bacterial species or strain. Traditional LPS quantification assays cannot distinguish between the acylation degree of lipid A molecules, and therefore little is known about how bacteria with different inflammation-inducing potencies affect fractional exhaled nitric oxide (FeNO). We aimed to explore the association between pro-inflammatory hexa- and less inflammatory penta-acylated LPS-producing oral bacteria and FeNO as a marker of airway inflammation.METHODS: We used data from a population-based adult cohort from Norway (n = 477), a study center of the RHINESSA multi-center generation study. We applied statistical methods on the bacterial community- (prediction with MiRKAT) and genus-level (differential abundance analysis with ANCOM-BC) to investigate the association between the oral microbiota composition and FeNO.RESULTS: We found the overall composition to be significantly associated with increasing FeNO levels independent of covariate adjustment, and abundances of 27 bacterial genera to differ in individuals with high FeNO vs. low FeNO levels. Hexa- and penta-acylated LPS producers made up 2.4% and 40.8% of the oral bacterial genera, respectively. The Bray-Curtis dissimilarity within hexa- and penta-acylated LPS-producing oral bacteria was associated with increasing FeNO levels independent of covariate adjustment. A few single penta-acylated LPS producers were more abundant in individuals with low FeNO vs. high FeNO, while hexa-acylated LPS producers were found not to be enriched.CONCLUSIONS: In a population-based adult cohort, FeNO was observed to be associated with the overall oral bacterial community composition. The effect of hexa- and penta-acylated LPS-producing oral bacteria was overall significant when focusing on Bray-Curtis dissimilarity within each of the two communities and FeNO levels, but only penta-acylated LPS producers appeared to be reduced or absent in individuals with high FeNO. It is likely that the pro-inflammatory effect of hexa-acylated LPS producers is counteracted by the dominance of the more abundant penta-acylated LPS producers in this population-based adult cohort involving mainly healthy individuals.
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