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| 3. |
- Angelov, Christo, et al.
(författare)
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High-mountain monitoring of persistent organic pollutants at the basic environmental observatory moussala
- 2014
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Ingår i: Comptes Rendus de l'Academie Bulgare des Sciences / Proceedings of the Bulgarian Academy of Sciences. - : Publishing House Bulgarian Academy of Sciences. - 1310-1331 .- 2367-5535. ; 67:8, s. 1129-1136
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we present the performance of the equipment for passive air sampling installed at Basic Environmental Observatory (BEO) Moussala, together with the first results obtained during the campaigns conducted in the period March 2009 March 2011 within the framework of the network for POP monitoring (MONET EU Project).The advantage of sampling at BEO Moussala is that the observatory is located at a high altitude (Moussala Peak, 2925 m above sea level), away from industrial polluters and large transportation fluxes. This unique location allows one to gather data from a large region subjected to the influence of transboundary Mediterranean and continental air masses. This would further open possibilities for studying the pollutants' levels and their correlation with the local climatic factors, the latter being well known in this region.
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| 4. |
- Arsov, Stefan, et al.
(författare)
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Advanced glycation end-products and skin autofluorescence in end-stage renal disease : a review
- 2014
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter. - 1434-6621 .- 1437-4331. ; 52:1, SI, s. 11-20
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Forskningsöversikt (refereegranskat)abstract
- Chronic kidney disease (CKD), especially in its end stage, is marked by extremely high cardiovascular rates of morbidity and mortality; hemodialysis patients have a five-fold shorter life expectancy than healthy subjects of the same age. In CKD the metabolic products that accumulate in the body are so-called uremic toxins. These include advanced glycation end-products (AGE). AGE levels are markedly increased in CKD patients not only because of impaired excretion but also because of increased production. AGE formation has initially been described as a non-enzymatic reaction between proteins and glucose in the so-called Maillard reaction, but they are also more rapidly formed during oxidative stress and subsequent formation of reactive carbonyl compounds like (methyl) glyoxal. AGE accumulate in tissue where they cross-link with proteins, e. g., collagen, inducing tissue stiffening of blood vessels and skin. They may also interact with receptor of AGE (RAGE) and other receptors, which lead to activation of intracellular transduction mechanisms resulting in cytokine release and further tissue damage in CKD. The accumulation of AGE in the skin can be measured non-invasively using autofluorescence. The skin autofluorescence is a strong marker of cardiovascular mortality in CKD. The focus of this review is on the role of tissue and plasma AGE, and of skin autofluorescence as a proxy of tissue AGE accumulation, in the increase in cardiovascular disease in end stage renal disease (ESRD). This review will also present the possibility of reducing the AGE accumulation in ESRD patients using the following five methods: 1) use of low AGE peritoneal dialysis solutions; 2) use of advanced hemodialysis techniques; 3) use of AGE reducing drugs; 4) optimizing the nutrition of hemodialysis patients; and 5) renal transplantation.
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| 5. |
- Arsov, Stefan, et al.
(författare)
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Does hepatitis C increase the accumulation of advanced glycation end products in haemodialysis patients?
- 2010
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Ingår i: Nephrology, Dialysis and Transplantation. - : Oxford Journals. - 0931-0509 .- 1460-2385. ; 25:3, s. 885-891
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Hepatitis C may cause increased levels of oxidative stress that contribute to accumulation of advanced glycation end products (AGEs), which increase the risk of cardiovascular disease (CVD). The aim of this study was to determine the influence of hepatitis C on AGE accumulation in haemodialysis patients. METHODS: AGE accumulation was measured by means of skin autofluorescence (AF) in 92 haemodialysis (HD) patients and 93 age-matched healthy controls. In the HD patients, CVD-related biochemical variables were also measured. The HD patients were tested for hepatitis C virus (HCV) antibodies and allocated to a HCV+ or HCV- group. RESULTS: Skin AF of the healthy subjects was lower than skin AF in the HD patients (3.13 +/- 0.95 vs 2.2 +/- 0.47; P < 0.001). We calculated the average increase of skin AF in the healthy subjects to be 0.017 arbitrary units per year, being 14 times lower than in HD patients with CVD only and 20 times lower than in HD patients suffering from combined CVD and diabetes mellitus (DM). Multivariate regression analysis showed that AGE accumulation in HD patients can be described by the independent effects of age, DM, CVD and HD vintage. Although inter-cellular adhesion molecule 1 and liver enzymes were elevated in HCV+ HD patients, levels of oxidative stress markers and skin AF were not significantly different between HCV+ and HCV- HD patients. CONCLUSIONS: AGE accumulation was higher in the HD patients than in the healthy controls. AGE accumulation did not differ in HCV+ and HCV- HD patients. This might be due to the fact that hepatitis C did not cause oxidative stress in our HD population. Independent markers of AGE accumulation were age, HD vintage, DM and CVD, but not hepatitis C.
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| 6. |
- Arsov, Stefan, et al.
(författare)
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Increase in skin autofluorescence and release of heart-type fatty acid binding protein in plasma predicts mortality of hemodialysis patients
- 2013
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Ingår i: Artificial Organs. - : Wiley. - 0160-564X .- 1525-1594. ; 37:7, s. E114-E122
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Tidskriftsartikel (refereegranskat)abstract
- Advanced glycation end-products (AGEs) are uremic toxins that accumulate progressively in hemodialysis (HD) patients. The aim of this study was to assess the 1-year increase in skin autofluorescence (DAF), a measure of AGEs accumulation and plasma markers, as predictors of mortality in HD patients. One hundred sixty-nine HD patients were enrolled in this study. Skin autofluorescence was measured twice, 1 year apart using an AGE Reader (DiagnOptics Technologies BV, Groningen, The Netherlands). Besides routine blood chemistry, additional plasma markers including superoxide dismutase, myeloperoxydase, intercellular adhesion molecule 1 (ICAM-1), C-reactive protein (hs-CRP), heart-type fatty acid binding protein (H-FABP), and von Willebrand factor were measured at baseline. The mortality of HD patients was followed for 36 months. Skin autofluorescence values of the HD patients at the two time points were significantly higher (P < 0.001) than those of healthy subjects of the same age. Mean 1-year DAF of HD patients was 0.16 +/- 0.06, which was around seven-to ninefold higher than 1-year DAF in healthy subjects. Multivariate Cox regression showed that age, hypertension, 1-year DAF, hs-CRP, ICAM-1, and H-FABP were independent predictors of overall mortality. Hypertension, 1-year DAF, hs-CRP, and H-FABP were also independent predictors of cardiovascular mortality. One-year DAF and plasma H-FABP, used separately and in combination, are strong predictors of overall and cardiovascular mortality in HD patients.
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| 7. |
- Graaff, Reindert, et al.
(författare)
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Skin and Plasma Autofluorescence During Hemodialysis : A Pilot Study
- 2014
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Ingår i: Artificial Organs. - : Wiley. - 0160-564X .- 1525-1594. ; 38:6, s. 515-518
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Tidskriftsartikel (refereegranskat)abstract
- Skin autofluorescence (AF) is related to the accumulation of advanced glycation end products (AGEs) and is one of the strongest prognostic markers of mortality in hemodialysis (HD) patients. The aim of this pilot study was to investigate whether changes in skin AF appear after a single HD session and if they might be related to changes in plasma AF. Skin and plasma AF were measured before and after HD in 35 patients on maintenance HD therapy (nine women and 26 men, median age 68 years, range 33-83). Median dialysis time was 4h (range 3-5.5). Skin AF was measured noninvasively with an AGE Reader, and plasma AF was measured before and after HD at 460nm after excitation at 370nm. The HD patients had on average a 65% higher skin AF value than age-matched healthy persons (P<0.001). Plasma AF was reduced by 14% (P<0.001), whereas skin AF was not changed after a single HD treatment. No significant influence of the reduced plasma AF on skin AF levels was found. This suggests that the measurement of skin AF can be performed during the whole dialysis period and is not directly influenced by the changes in plasma AF during HD.
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| 8. |
- Ramsauer, Bernd, et al.
(författare)
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Comparing changes in plasma and skin autofluorescence in low-flux versus high-flux hemodialysis
- 2015
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Ingår i: International Journal of Artificial Organs. - : SAGE Publications. - 0391-3988 .- 1724-6040. ; 38:9, s. 488-493
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Tidskriftsartikel (refereegranskat)abstract
- Background: Tissue advanced glycation end products (AGE) are increased in hemodialysis (HD) patients, especially those with cardiovascular complications. Skin autofluorescence (skin-AF) can noninvasively estimate the accumulation of AGE in tissue. The aim was to clarify whether HD using a high-flux (HF) dialyzer favors plasma-or skin-AF removal compared to low-flux (LF) dialysis. Material and methods: 28 patients were treated with either an HF-HD or LF-HD but otherwise unchanged conditions in a cross-over design. A glucose containing dialysate was used. Skin-AF was measured noninvasively with an AGE reader before and after HD. Fluorescence (370 nm/465 nm) of plasma (p-AF) was determined as total and nonprotein-bound fractions. Correction for hemoconcentrations were made using the change in serum albumin. Paired and nonpaired statistical analyses were used. Results: Skin-AF was unchanged after LF- and HF-dialysis. Total, free, and protein-bound p-AF was reduced after a single LF-HD by 21%, 28%, and 17%, respectively (P<.001). After HF HD total and free p-AF was reduced by 5% and 15%, respectively (P<.001), while protein bound values were unchanged. The LF-HD resulted in a more pronounced reduction of p-AF than did HF HD (P<.001). Serum albumin correlated inversely with p-AF in HF-HD. Conclusions: In the dialysis settings used there was no significant change in skin AF after dialysis, with LF or with HF dialysis. Although only limited reduction in plasma fluorescence was observed, this was more pronounced when performing LF dialysis. These data are not in overwhelming support of the use of HF dialysis in the setting used in this study.
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| 9. |
- Ramsauer, Bernd, et al.
(författare)
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Skin- and Plasmaautofluorescence in hemodialysis with glucose-free or glucose-containing dialysate
- 2017
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Ingår i: BMC Nephrology. - : Springer Science and Business Media LLC. - 1471-2369. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Background: Haemodialysis (HD) patients suffer from an increased risk of cardiovascular disease (CVD). Skinautofluorescence (SAF) is a strong marker for CVD. SAF indirectly measures tissue advanced glycation end products(AGE) being cumulative metabolites of oxidative stress and cytokine-driven inflammatory reactions. The dialysatesoften contain glucose.Methods: Autofluorescence of skin and plasma (PAF) were measured in patients on HD during standard treatment(ST) with a glucose-containing dialysate (n = 24). After that the patients were switched to a glucose-free dialysate(GFD) for a 2-week period. New measurements were performed on PAF and SAF after 1 week (M1) and 2 weeks(M2) using GFD. Nonparametric paired statistical analyses were performed between each two periods.Results: SAF after HD increased non-significantly by 1.2% while when a GFD was used during HD at M1, a decreaseof SAF by 5.2% (p = 0.002) was found. One week later (M2) the reduction of 1.6% after the HD was not significant(p = 0.33). PAF was significantly reduced during all HD sessions. Free and protein-bound PAF decreased similarlywhether glucose containing or GFD was used. The HD resulted in a reduction of the total PAF of approximately15%, the free compound of 20% and the protein bound of 10%. The protein bound part of PAF correspondedto approximately 56% of the total reduction. The protein bound concentrations after each HD showed thelowest value after 2 weeks using glucose-free dialysate (p < 0.05). The change in SAF could not be related to achange in PAF.Conclusions: When changing to a GFD, SAF was reduced by HD indicating that such measure may hamperthe accumulation and progression of deposits of AGEs to protein in tissue, and thereby also the developmentof CVD. Glucose-free dialysate needs further attention. Protein binding seems firm but not irreversible.
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| 10. |
- Ramsauer, Bernd, 1954-, et al.
(författare)
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Skin Autofluorescence, a Measure of Cumulative Metabolic Stress and Advanced Glycation End Products, Decreases During the Summer in Dialysis Patients
- 2019
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Ingår i: Artificial Organs. - : Wiley Periodicals, Inc.. - 0160-564X .- 1525-1594. ; 43:2, s. 173-180
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Tidskriftsartikel (refereegranskat)abstract
- Tissue advanced glycation end products (AGEs) are a measure of cumulative metabolic and oxidative stress and cytokine-driven inflammatory reactions. AGEs are thought to contribute to the cardiovascular complications of hemodialysis (HD) patients. Skin autofluorescence (SAF) is related to the tissue accumulation of AGEs and rises with age. SAF is one of the strongest prognostic markers of mortality in these patients. The content of AGEs is high in barbecue food. Due to the location in northern Sweden, there is a short intense barbecue season between June and August. The aim of this study was to investigate if seasonal variations in SAF exist in HD patients, especially during the barbecue season. SAF was measured noninvasively with an AGE Reader in 34 HD-patients (15 of those with diabetes mellitus, DM). Each time the median of three measures were used. Skin-AF was measured before and after each one HD at the end of February and May in 31 patients (22 men/9 women); the end of May and August in 28 (20 m/8 w); the end of August and March in 25 (19 m/6 w). Paired statistical analyses were performed during all four periods (n = 23, 17 m/6 w); as was HbA1c of those with DM. There was at a median 5.6% increase in skin-AF during the winter period (February-May, P = 0.004) and a 10.6% decrease in the skin-AF during the summer (May-August, P < 0.001). HbA1c in the DM rose during the summer (P = 0.013). In conclusion, skin-AF decreased significantly during the summer. Future studies should look for favorable factors that prevent skin-AF and subsequently cardiovascular diseases.
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