The association between various smoking behaviors, cotinine biomarkers and skin autofluorescence, a marker for advanced glycation end product accumulation.

Background: Skin autofluorescence, a biomarker for advanced glycation end products (AGEs) accumulation, has been shown to predict diabetes-related cardiovascular complications and is associated with several environmental and lifestyle factors. In the present study, we examined the association between various smoking behaviors and skin autofluorescence, as well as the association between several cotinine biomarkers and skin autofluorescence, using both epidemiological and metabolomics data. Methods: In a cross-sectional study, we evaluated participants from the LifeLines Cohort Study and the Qatar Metabolomics Study on Diabetes (QMDiab). In the LifeLines Cohort Study smoking behavior and secondhand smoking were assessed in 8,905 individuals including 309 individuals (3.5%) with type 2 diabetes. In QMDiab, cotinine biomarkers were measured in saliva, plasma and urine in 364 individuals of whom 188 (51%) had type 2 diabetes. Skin autofluorescence was measured non-invasively in all participants using the AGE Reader. Results: Skin autofluorescence levels increased with a higher number of hours being exposed to secondhand smoking. Skin autofluorescence levels of former smokers approached levels of never smokers after around 15 years of smoking cessation. Urinary cotinine N-oxide, a biomarker of nicotine exposure, was found to be positively associated with skin autofluorescence in the QMDiab study (p = 0.03). Conclusions: In the present study, we have demonstrated that secondhand smoking is associated with higher skin autofluorescence levels whereas smoking cessation has a beneficial effect on skin autofluorescence. Finally, urinary cotinine N-oxide might be used as an alternative way for questionnaires to examine the effect of (environmental) tobacco smoking on skin autofluorescence

Ouderdom en ontstaanswijze van cirkelvormige eikenstrubben in het natuurterrein "De Wilde Kamp" bij Garderen (Noordwest-Veluwe) : Tussentijds verslag van een interdisciplinair onderzoek

Het onderzoek dat in dit rapport wordt besproken is een direct gevolg van het reguliere overleg dat de Stichting Het Geldersch Landschap en de Rijksdienst voor het Oudheidkundig Bodemonderzoek in de afgelopen jaren met elkaar hebben gevoerd over het beheer van cultuurhistorische waarden in natuurterreinen. Aanleiding voor het project was de ontdekking in 2001-2002 van mogelijk eeuwenoude cirkelvormige eikenstrubben op de Veluwe tijdens een inventarisatie van inheemse bomen en struiken door de ecologen Chris Rövekamp en Bert Maes1. Hoewel hun ontdekkingen veel opzien baarden in de regionale en landelijke pers, was er vanuit de vakwereld ook veel twijfel over de geldigheid van hun conclusies ten aanzien van de genese en ouderdom van deze oude eiken. Om meer duidelijkheid over de ontstaanswijze, mogelijke ouderdom en cultuurhistorische waarden van deze historische bosopstanden te krijgen en ter voorbereiding van een in de nabije toekomst te vervaardigen beheersplan voor het natuurterrein ‘De Wilde Kamp’ bij Garderen besloten ROB en Geldersch Landschap in 2003 tot de uitvoering van een interdisciplinair verkennend onderzoek naar de eikenclusters in bovengenoemd natuurterrein. Vanaf 2004 participeerde ook het Centrum voor Ecosystemen van Wageningen Universiteit actief in het project

Influence of storage and inter- and Intra-assay variability on the measurement of inflammatory biomarkers in population-based biobanking.

BACKGROUND: In the present study, we examined the effect of sample storage on the reproducibility of several inflammatory biomarkers, including high-sensitivity C-reactive protein (hsCRP), high-sensitivity interleukin-6 (hsIL6), and high-sensitivity tumor necrosis factor alpha (hsTNFα). In addition, we assessed inter- and intra-assay variability between collaborating biobanks. METHODS: In total, 240 fasting plasma samples were obtained from the LifeLines biobank. Samples had been stored for less than 2 or more than 4 years at -80°C. Measurements were performed at three different laboratories. hsCRP was measured by immunonephelometry and ELISA, hsIL6, and hsTNFα samples were measured with ELISAs from two different manufacturers. For confirmation, similar analyses were performed on samples obtained from a subpopulation of 80 obese individuals. Passing-Bablok regression analysis and Bland-Altman plots were used to compare the results. RESULTS: We observed good stability of samples stored at -80°C. hsCRP measured on the day of blood draw was similar to levels measured after more than 4 years of storage. There were small interlaboratory differences with the R&D ELISAs for hsIL6 and hsTNFα. We found a linear correlation between the Bender Medsystems ELISA and the R&D ELISA for hsIL6, with significantly higher levels measured with the R&D ELISA. Over 90% of hsTNFα samples measured with the IBL ELISA were below the detection limit of 0.13 ng/L, rendering this assay unsuitable for large-scale analysis. Similar results were found in the confirmation study. CONCLUSION: In summary, plasma hsCRP showed good stability in samples stored for either less than 2 years or more than 4 years at -80°C. Both the R&D and Bender Medsystems for hsIL6 measurement yielded similar results. The IBL hsTNFα assay is not suited for use in biobanking samples. Assays for the measurement of inflammatory biomarker assays should be rigorously tested before large sample sets are measured

Skin autofluorescence is related to tobacco smoke and nicotine exposure.

Clinical epidemiolog