626 research outputs found

    Cigarette smoking cessation increases plasma levels of several antioxidant micronutrients and improves resistance towards oxidative challenge

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    Cigarette smoking is associated epidemiologically with increased risk of cardiovascular diseases, but the pathophysiological mechanisms are still not fully understood. There is evidence that smoking is related to increased free radical production and antioxidant depletion, but the effects of smoking cessation on plasma concentrations of antioxidants and susceptibility to oxidative stress are largely unknown. Plasma levels of vitamins A, C, E, uric acid, total thiols, carotenoids (including lutein, zeaxanthin, β-cryptoxanthin, lycopene, α- and β-carotene) and malondialdehyde (MDA, a biomarker of lipid peroxidation) were measured in fifteen healthy, normolipidaemic subjects (seven males, eight females, 35·2 (sd2·3) years) before and 4 weeks after smoking cessation. To determine plasma resistance towards oxidative challenge, plasma was incubated for up to 5h with the peroxyl radical-generator 2,2′-azobis(2-amidinopropane) (AAPH); MDA and ascorbate levels were measured at various time points. The concentrations of all plasma antioxidants were lower before smoking cessation than afterwards; MDA levels were higher before than after termination of smoking. Upon AAPH exposure, the consumption of plasma ascorbate and the production of MDA occurred at a significantly faster rate before smoking cessation as compared with afterwards. Cigarette smoking cessation is followed by a marked increase in plasma antioxidant concentrations and substantially improves plasma resistance towards oxidative challenge. Given the importance of cigarette smoking as a risk factor for cardiovascular diseases and the pathophysiological role played by oxidative stress in these illnesses, quitting smoking represents an irreplaceable preventive strategy against tobacco-induced oxidative stress and vascular damage

    Health economic evaluation of moist wound care in chronic cutaneous leishmaniasis ulcers in Afghanistan

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    Background: The present health economic evaluation in Afghanistan aims to support public health decision makers and health care managers to allocate resources efficiently to appropriate treatments for cutaneous leishmaniasis (CL) elicited by Leishmania tropica or Leishmania major. Methods: A decision tree was used to analyse the cost and the effectiveness of two wound care regimens versus intra-lesional antimony in CL patients in Afghanistan. Costs were collected from a societal perspective. Effectiveness was measured in wound free days. The incremental cost-effectiveness ratio (ICER) and incremental net monetary benefit (NMB) were calculated. The model was parameterized with baseline parameters, sensitivity ranges, and parameter distributions. Finally, the model was simulated and results were evaluated with deterministic and probability sensitivity analyses. Final outcomes were the efficiency of the regimens and a budget impact analysis in the context of Afghanistan. Results: Average costs per patients were US11(SE=0.016)(GroupI:IntradermalSodiumStibogluconate[ILSSG]),US 11 (SE = 0.016) (Group I: Intra-dermal Sodium Stibogluconate [IL SSG]), US 16 (SE = 7.58) (Group II: Electro-thermo-debridement [ETD] + Moist wound treatment [MWT]) and US25(SE=0.48)(GroupIII:MWT)inpatientswithasinglechronicCLulcer.Fromasocietalperspectivethebudgetimpactanalysisshowsthattheregimensdrugcostsarelowerthanindirectdiseasecost.Averageeffectivenessinwoundfreedaysare177(SE=0.36)inGroupII,147(SE=0.33)inGroupIII,and129(SE=0.27)inGroupI.TheICERofGroupIIversusGroupIwasUS 25 (SE = 0.48) (Group III: MWT) in patients with a single chronic CL ulcer. From a societal perspective the budget impact analysis shows that the regimens’ drug costs are lower than indirect disease cost. Average effectiveness in wound free days are 177 (SE = 0.36) in Group II, 147 (SE = 0.33) in Group III, and 129 (SE = 0.27) in Group I. The ICER of Group II versus Group I was US 0.09 and Group III versus Group I US0.77,whichisverycosteffectivewithawillingnesstopaythresholdofUS 0.77, which is very cost-effective with a willingness-to-pay threshold of US 2 per wound free day. Within a Monte-Carlo probabilistic sensitivity analysis Group II was cost-effective in 80% of the cases starting at a willingness-to-pay of 80 cent per wound free day. Conclusions: Group II provided the most cost-effective treatment. The non-treatment alternative is not an option in the management of chronic CL ulcers. MWT of Group III should at least be practiced. The cost-effectiveness of Group III depends on the number of dressings necessary until complete wound closure

    Immune-mediated mesangial cell injury—Biosynthesis and function of prostanoids

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    Immune-mediated mesangial cell injury—Biosynthesis and function of prostanoids. We studied the formation of cyclo-oxygenase products in a rat model of mesangial cell injury, in order to determine a possible role of prostaglandin E2 (PGE2), prostaglandin I2 (determined as 6-keto-PGF1α and thromboxane A2 (TxA2) in immune-mediated glomerular disease. Selective immune-mediated mesangial cell injury was induced by i.v. administration of a rabbit anti-rat thymocyte antiserum (ATS). Intravenous ATS leads to immune deposits in the mesangium followed by mesangiolysis and the infiltration of polymorphonuclear granulocytes and monocytes. Glomerular TxB2 formation two hours (292 ± 27 pg/mg/min) and 48 hours (396 ± 69 pg/mg/min) following antibody was significantly (P < 0.05) higher compared to animals receiving non-antibody rabbit IgG (TxB2: 2hr 143 ± 13; 48hr 171 ± 32 pg/mg/min). Treatment with cobra venom factor (CVF) and the reduction of glomerular monocyte infiltration inhibited the increase of glomerular TxB2 formation significantly. Depletion of granulocytes with a rabbit anti-rat granulocyte serum had no effect on glomerular prostanoid formation following ATS. Glomerular PGE2 and 6-keto PGF1α production was not altered following ATS. Inulin clearance in rats with immune-mediated mesangial cell injury was significantly (P < 0.001) lower at two hours (456 ± 24 µl/min/100g body wt) and 48 hours (433 ± 54 µl/min/lOO g body wt) compared to their corresponding control animals which were treated with non-antibody IgG (2 hr: 914 ± 51; 48 hr: 694 ± 79 µl/min/100g body wt). Pretreatment of rats with indomethacin (Indo) or with the thromboxane synthetase inhibitor UK 38485 prevented the decrease in inulin clearance following ATS at two hours (Indo: 800 ± 67; UK 38485: 923 ± 115) and at 48 hours (Indo: 697 ± 60; UK 38485: 654 ± 99). The data demonstrate that selective, immune-mediated mesangial cell injury in rats is associated with increased glomerular TxB2 formation. Complement and monocyte/macrophage depletion reduces TxB2 production. The fall in inulin clearance following ATS is ameliorated when the rats receive indomethacin or the Tx synthetase inhibitor UK 38485. Thus, elevated TxB2 formation might mediate the reduction in GFR in this model of glomerular immune injury

    Activation of Nrf2 by electrophiles is largely independent of the selenium status of HepG2 cells

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    Selenoenzymes, whose activity depends on adequate selenium (Se) supply, and phase II enzymes, encoded by target genes of nuclear factor erythroid 2-related factor 2 (Nrf2), take part in governing cellular redox homeostasis. Their interplay is still not entirely understood. Here, we exposed HepG2 hepatoma cells cultured under Se-deficient, Se-adequate, or Se-supranutritional conditions to the Nrf2 activators sulforaphane, cardamonin, or diethyl maleate. Nrf2 protein levels and intracellular localization were determined by immunoblotting, and mRNA levels of Nrf2 target genes and selenoproteins were assessed by qRT-PCR. Exposure to electrophiles resulted in rapid induction of Nrf2 and its enrichment in the nucleus, independent of the cellular Se status. All three electrophilic compounds caused an enhanced expression of Nrf2 target genes, although with differences regarding extent and time course of their induction. Whereas Se status did not significantly affect mRNA levels of the Nrf2 target genes, gene expression of selenoproteins with a low position in the cellular “selenoprotein hierarchy”, such as glutathione peroxidase 1 (GPX1) or selenoprotein W (SELENOW), was elevated under Se-supplemented conditions, as compared to cells held in Se-deficient media. In conclusion, no major effect of Se status on Nrf2 signalling was observed in HepG2 cells

    Partial Mitigation of Oxidized Phospholipid-Mediated Mitochondrial Dysfunction in Neuronal Cells by Oxocarotenoids

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    Mitochondria are important (patho)physiological sources of reactive oxygen species (ROS) that mediate mitochondrial dysfunction and phospholipid oxidation; an increase in mitochondrial content of oxidized phospholipid (OxPL) associates with cell death. Previously we showed that the circulating OxPL 1-palmitoyl-2-(5’-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC) increases in patients with Alzheimer’s disease (AD), and associates with lower plasma antioxidant oxocarotenoids, zeaxanthin, and lutein. Since oxocarotenoids are metabolized in mitochondria, we propose that during AD, lower concentrations of mitochondrial zeaxanthin and lutein may result in greater phospholipid oxidation and predispose to neurodegeneration. Here, we have investigated whether non-toxic POVPC concentrations impair mitochondrial metabolism in differentiated (d)SH-SY5Y neuronal cells and whether there is any protective role for oxocarotenoids against mitochondrial dysfunction. After 24 hours, glutathione (GSH) concentration was lower in neuronal cells exposed to POVPC (1–20μM) compared with vehicle control without loss of viability compared to control. However, mitochondrial ROS production (determined by MitoSOX oxidation) was increased by 50% only after 20μM POVPC. Following delivery of lutein (0.1-1μM) and zeaxanthin (0.5-5μM) over 24 hours in vitro, oxocarotenoid recovery from dSH-SY5Y cells was >  50%. Co-incubation with oxocarotenoids prevented loss of GSH after 1μM but not 20μM POVPC, whereas the increase in ROS production induced by 20μM POVPC was prevented by lutein and zeaxanthin. Mitochondrial uncoupling increases and ATP production is inhibited by 20μM but not 1μM POVPC; carotenoids protected against uncoupling although did not restore ATP production. In summary, 20μM POVPC induced loss of GSH and a mitochondrial bioenergetic deficit in neuronal cells that was not mitigated by oxocarotenoids

    Cystic fibrosis (CF) care through the patients' eyes – A nationwide survey on experience and satisfaction with services using a disease-specific questionnaire

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    SummaryThe patients' perspective is an important aspect of quality management. A newly developed disease-specific questionnaire was used to assess the patients' experiences with care provided in specialised cystic fibrosis (CF) care centres.Methods90 CF centres in Germany were invited to participate. Centre staff collected patient consent forms and sent the patients' addresses to the study centre. The questionnaires for adults and parents had 100 and 104 items respectively, with 3–6 response categories each. Items were dichotomised into “problem scores” (PS), indicating the presence or absence (PS 0%) of a reported problem.Results56 CF centres took part in the survey and recruited 1642 adults with CF and 1205 parents. The response rates were 74% in each group, with 1221 completed questionnaires from adults and 891 from parents. Participants reported good experiences with care. Factor analysis revealed 10 factors covering 70 items. Participants reported the best results for the factors “Physiotherapists” (PS 6%) and “Physician–Patient Relationship” (PS 9%). Factors with the highest problem scores were inpatient and outpatient “Facilities, Hygiene and Services”. CF centres received reports of their own results and mean problem scores of all participating institutions. The problem scores differed considerably between CF centres.ConclusionsThe nation-wide CF-specific patient experience survey identified specific shortcomings which were mainly related to communication, centre organisation, and facilities. Centre staff can use the results to improve the quality of care. We suggest that patients' views should become an integral component of efforts to promote patient-centred care
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