130 research outputs found

    Clinical and biochemical correlates of serum L-ergothioneine concentrations in community-dwelling middle-aged and older adults

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    Background: Despite the increasing interest towards the biological role of L-ergothioneine, little is known about the serum concentrations of this unusual aminothiol in older adults. We addressed this issue in a representative sample of communitydwelling middle-aged and older adults. Methods: Body mass index, estimated glomerular filtration rate, serum concentrations of L-ergothioneine, taurine, homocysteine, cysteine, glutathione, cysteinylglycine, and glutamylcysteine were evaluated in 439 subjects (age 55–85 years) randomly selected from the Hunter Community Study. Results: Median L-ergothioneine concentration in the entire cohort was 1.01 IQR 0.78–1.33 mmol/L. Concentrations were not affected by gender (P = 0.41) or by presence of chronic medical conditions (P = 0.15). By considering only healthy subjects, we defined a reference interval for L-ergothioneine serum concentrations from 0.36 (90% CI 0.31–0.44) to 3.08 (90% CI 2.45–3.76) mmol/L. Using stepwise multiple linear regression analysis L-ergothioneine was negatively correlated with age (rpartial =20.15; P = 0.0018) and with glutamylcysteine concentrations (rpartial =20.13; P = 0.0063). Conclusions: A thorough analysis of serum L-ergothioneine concentrations was performed in a large group of communitydwelling middle-aged and older adults. Reference intervals were established. Age and glutamylcysteine were independently negatively associated with L-ergothioneine serum concentration.</br

    Plasma L-ergothioneine measurement by high-performance liquid chromatography and capillary electrophoresis after a pre-column derivatization with 5-iodoacetamidofluorescein (5-IAF) and fluorescence detection

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    Two sensitive and reproducible capillary electrophoresis and high-performance liquid chromatography-fluorescence procedures were established for quantitative determination of L-egothioneine in plasma. After derivatization of L-ergothioneine with 5-iodoacetamidofluorescein, the separation was carried out by HPLC on an ODS-2 C-18 sperisorb column by using a linear gradient elution and by HPCE on an uncoated fused silica capillary, 50 µm id, and 60 cm length. The methods were validated and found to be linear in the range of 0.3 to 10 µmol/l. The limit of quantification was 0.27 µmol/l for HPCE and 0.15 µmol/l for HPLC. The variations for intra- and inter-assay precision were around 6 RSD%, and the mean recovery accuracy close to 100% (96.11%)

    The Oxidative state of LDL is the major determinant of anti/prooxidant effect of coffee on Cu<sup>2+</sup> catalysed peroxidation

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    Antioxidants exert contrasting effect on low density lipoprotein (LDL) oxidation catalysed by metals, acting as pro-oxidants under select in vitro conditions. Through our study on the effect of coffee on LDL oxidation, we identified the parameters governing this phenomenon, contributing to the comprehension of its mechanism and discovering significant implications for correct alimentary recommendations. By measuring conjugated diene formation, we have analysed the quantitative and qualitative effects exerted by an extract of roasted coffee on LDL oxidation triggered by copper sulphate. When the relative effects of different coffee concentrations were plotted against the lag time (LT) of control LDL (C-LDL), the apparently random experimental data arranged in sensible patterns: by increasing the LT the antioxidant activity of coffee decreased progressively to become prooxidant. The critical LT, at which coffee switches from antioxidant to prooxidant, increased by increasing coffee concentration. Also the contrasting results obtained following a delayed addition of coffee to the assay, arranged in a simple pattern when referred to the LT of C-LDL: the prooxidant effect decreased to become antioxidant as the LT of C-LDL increased. The dependence of coffee effect on the LT of C-LDL was influenced by LDL but not by metal catalyst concentration. These novel findings point to the oxidative state of LDL as a major parameter controlling the anti/prooxidant effect of coffee and suggest the LT of C-LDL as a potent analytical tool to express experimental data when studying the action exerted by a compound on LDL oxidation

    A Protocol for microbiologically safe preparation, storage, and use of autologous serum eye-drops in low-income countries

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    Introduction: The study aimed to investigate whether the preparation, storage, and use of autologous serum in insulin syringes is microbiologically safe. Methodology: Blood samples (10 mL) were obtained from 10 volunteers. After centrifugation, the supernatant serum was removed and distributed in 5 sterile insulin syringes for each sample; syringes were numbered 0 to 4 and labelled with the subject’s details. Syringes were immediately transported to the microbiology laboratory and stored in a refrigerator at +4°C. The “0” labelled syringes were separated from the others and 100 μl of serum from each syringe was immediately seeded on chocolate and Sabouraud agar plates, which were incubated aerobically at 37°C for 96 hours to detect any bacterial and/or fungal contamination. In the next 4 days, the same procedure was repeated for the remaining syringes: on day 1, the “1” labelled syringes were analyzed; on day 2, the “2” labelled ones, and so on. In a second experiment, blood samples were obtained from 5 different volunteers. The same procedure as above was followed, but each syringe was used for repeated cultures at 2-hour intervals, for a total of 12 cultures/day. The needle was removed and replaced for each inoculation and the syringes were stored in the refrigerator after use. Results: Under these experimental conditions, none of the cultures showed microbial growth. Conclusions: Results suggest that, under the protocol described, preparation, storage and use of undiluted autologous serum in insulin syringes is inexpensive, fast, and microbiologically safe. This is of great importance for low-income countries.</br

    Human serum albumin increases the stability of green tea catechins in aqueous physiological conditions

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    Epicatechin (EC), epigallocatechin (EGC), epicatechingallate (ECG) and epigallocatechingallate (EGCG) are antioxidants present in the green tea, a widely used beverage whose health benefits are largely recognized. Nevertheless, major physicochemical limitations, such as the high instability of catechins, pose important questions concerning their potential pharmacological use. Recent studies indicate that binding of catechins with plasmatic proteins may modulate their plasma concentration, tissue delivery and biological activity. After 5 minutes of incubation with HSA both ECG and EGCG were fully bound to HSA, while after 48h incubation only 41% of EC and 70% of EGC resulted linked. HSA had a strong stabilizing effect on all catechins, which could be found in solution between 29 and 85% even after 48h of incubation. In the absence of HSA, EGC and EGCG disappeared in less than 24h, while ECG and EC were found after 48h at 5 and 50%, respectively. The stabilizing effect of HSA toward EGCG, obtained in aqueous physiological conditions, resulted stronger in comparison to cysteine and HCl, previously reported to stabilize this polyphenol. Because of the multitude of contradictory data concerning in vivo and in vitro antioxidant-based experimentations, we believe our work may shed some light on this debated field of research

    Neutrophil to lymphocyte ratio and clinical outcomes in COPD: recent evidence and future perspectives

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    Chronic obstructive pulmonary disease (COPD) is a disabling condition that is characterised by poorly reversible airflow limitation and inflammation. Acute exacerbations of COPD are a common cause of hospitalisation and death among COPD patients. Several biochemical markers have been studied as outcome predictors in COPD; however, their measurement often requires significant time and resources. Relatively simple biomarkers of inflammation calculated from routine complete blood count tests, such as the neutrophil to lymphocyte ratio (NLR), might also predict COPD progression and outcomes. This review discusses the available evidence from studies investigating the associations between the NLR, COPD exacerbations and death in this patient group

    Arginines Plasma Concentration and Oxidative Stress in Mild to Moderate COPD

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    This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background Elevated plasma concentrations of the endogenous nitric oxide synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) have been observed in respiratory conditions such as asthma and cystic fibrosis. Since oxidative stress has been shown to increase the activity of arginine methylating enzymes, hence increased ADMA synthesis, and to reduce ADMA degrading enzymes, hence increased ADMA concentrations, we assessed methylated arginines concentrations in chronic obstructive pulmonary disease (COPD), a disease characterized by increased oxidative stress. Methods Plasma arginine, ADMA and symmetric dimethylarginine (SDMA), oxidative stress markers (thiobarbituric acid reactive substances, TBARS, and plasma proteins SH, PSH) and antioxidants (taurine and paraoxonase 1, PON1, activity) were measured in 43 COPD patients with mild (n = 29) or moderate (n = 14) disease and 43 age- and sex-matched controls. Results TBARS significantly increased with COPD presence and severity (median 2.93 vs 3.18 vs 3.64 μmol/L, respectively in controls, mild and moderate group, p<0.0001 by ANOVA) whereas PSH decreased (6.69±1.15 vs 6.04±0.85 vs 5.33±0.96 μmol/gr prot, p<0.0001 by ANOVA). Increased ADMA/arginine ratio, primarily due to reduced arginine concentrations, was also observed with COPD presence and severity (median 0.0067 vs 0.0075 vs 0.0100, p<0.0001 by ANOVA). In multiple logistic regression analysis, only TBARS (OR 0.44, 95% CI 0.25–0.77; p = 0.0045) and ADMA/Arginine ratio (OR 1.72, 95% CI 2.27–13.05; p = 0.02) were independently associated with COPD severity. Conclusion COPD presence and severity are associated with increased oxidative stress and alterations in arginine metabolism. The reduced arginine concentrations in COPD may offer a new target for therapeutic interventions increasing arginine availability

    S-Methyl-L-Ergothioneine to L-Ergothioneine Ratio in Urine Is a Marker of Cystine Lithiasis in a Cystinuria Mouse Model

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    Cystinuria, a rare inherited aminoaciduria condition, is characterized by the hyperexcretion of cystine, ornithine, lysine, and arginine. Its main clinical manifestation is cystine stone formation in the urinary tract, being responsible for 1-2% total and 6-8% pediatric lithiasis. Cystinuria patients suffer from recurrent lithiasic episodes that might end in surgical interventions, progressive renal functional deterioration, and kidney loss. Cystinuria is monitored for the presence of urinary cystine stones by crystalluria, imaging techniques or urinary cystine capacity; all with limited predicting capabilities. We analyzed blood and urine levels of the natural antioxidant L-ergothioneine in a Type B cystinuria mouse model, and urine levels of its metabolic product S-methyl-L-ergothioneine, in both male and female mice at two different ages and with different lithiasic phenotype. Urinary levels of S-methyl-L-ergothioneine showed differences related to age, gender and lithiasic phenotype. Once normalized by L-ergothioneine to account for interindividual differences, the S-methyl-L-ergothioneine to L-ergothioneine urinary ratio discriminated between cystine lithiasic phenotypes. Urine S-methyl-L-ergothioneine to L-ergothioneine ratio could be easily determined in urine and, as being capable of discriminating between cystine lithiasis phenotypes, it could be used as a lithiasis biomarker in cystinuria patient management
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