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Age- and gender-related oxidative status determined in healthy subjects by means of OXY-SCORE, a potential new comprehensive index
No full textOxidative stress has been related to various diseases, gender and ageing, and has been measured by various markers. The authors developed a procedure to compute a global oxidative stress index (OXY SCORE), reflecting both oxidative and antioxidant markers in healthy subjects. Its performance was tested in relation to age and gender and in coronary artery disease (CAD) patients. Eighty-two healthy subjects and 20 CAD patients were enrolled. Plasma free and total malondialdehyde (F- and TMDA), glutathione disulphide/reduced form ratio (GSSG/GSH) and urine isoprostanes (iPF(2 alpha)-III) levels were combined as oxidative damage markers (damage score). GSH, alpha- and gamma-tocopherol (TH) levels, and individual antioxidant capacity were combined as antioxidant defence indexes (protection score). The OXY SCORE was computed by subtracting the protection score from the damage score. Among single parameters, TMDA and iPF(2 alpha)-III significantly correlated with age; only GSH and both tocopherols correlated with male gender in healthy subjects. The OXY SCORE was positively associated with age (p= 0.004) and male gender (p= 0.03). As expected, the OXY SCORE was higher in CAD with a very significant p-value ( < 0.0001), after adjusting for age, gender and smoking. Combining different markers can potentially provide a powerful index in the evaluation of oxidative stress related to age, gender and CAD status
Oxidative stress : a global evaluation in patients with acute coronary syndrome and stable angina
No full textBackground. Oxidative stress has been related to several pathologies, like coronary artery disease (CAD). We recently
described a comprehensive index of oxidative status (OXYSCORE),reflecting both injuries and antioxidant defences in coronary patients.
Objective: This study was performed to test OXY-SCORE.
Methods. We enrolled 93 healthy subjects (58% males; age 24-72) and 197 CAD patients, 118 with stable angina (SA,77% males; age 40-81) and 79 with acute coronary syndrome
(ACS, 70% males; age 35-80) . Plasma free and total malondialdehyde (F- and T-MDA), glutathione disulphide/reduced forms (GSSG/GSH) and urine isoprostane (iPF2α-III) levels were measured as markers of oxidative
damage, and computed in the damage score (DS). GSH, α-and γ-tocopherol (TH), and individual antioxidant capacity (IAC), measured as indexes of antioxidant defence, were computed in the protection score (PS). OXY-SCORE was computed by subtracting PS from DS. Data were analysed by ANCOVA and ROC analysis.
Results. In healthy subjects, MDA was associated with age and GSH, GSSG/GSH ratio and α-TH correlated with gender. OXY-SCORE (mean±SEM 0.31±0.10), was positively
associated with both age (p=0.02) and male gender (p=0.03). OXY-SCORE was significantly higher in CAD subjects even after adjusting for age and gender (p<0.0001) and was also
able to discriminate between ACS and AS (mean±SEM 1.4±0.11 and 0.92±0.08 respectively, p=0.001) with an area
under the ROC curve of 0.66.
Conclusions. OXY-SCORE is confirmed to be a
comprehensive index of oxidative stress related to age, gender and CAD status. This marker also reflects the different clinical
presentation of CAD
Atherosclerosis and dementia : implication of oxidative stress in the impairement of cognitive function
No full textMetabolomic evaluation of NO production in human erythrocytes: an LC-MS/MS method to asses arginine and its metabolites
No full textExperimental studies suggest that red blood cells are involved in nitric oxide (NO) synthesis and delivery. Erythrocytes acts as producers, scavengers and vehicles of NO affecting several physiological processes. NO bioavailability is linked not only to arginine and its metabolic products, ornithine and citrulline, but also to methylarginines which are inhibitors of NO sinthesis. Existing methodologies do not permit a systematic evaluation of the metabolic and biosynthetic pathway of NO in RBC. A metabolomic approach, considering a larger number of compounds involved in NO metabolic pathway, could be important to better understand the role of red blood cells in physiological and pathological conditions.
We set up an HPLC-electrospray ionization-tandem mass spectrometry method, to simultaneously detect and quantify arginine metabolome, i.e. arginine, symmetric and asymmetric dimethylarginine, monomethyarginine, ornithine, citrulline. Stable isotope-labelled internal standards have been used to minimize analytical variations before organic protein precipitation of the isolated and lysated erythrocytes. The ion source was operating in positive ion mode and the analytes were detected using multiple reaction monitoring after hydrophilic-interaction chromatography.
A 8 min run time allowed the simultaneous evaluation of all the analytes involved in the NO pathway. The chromatograms were free from interferences, the calibration functions were linear and the inter-day CV were<10% for all the analytes. LOQ values make this method suitable for low concentration samples.
Our validated LC-MS/MS method might be useful to clarify the role of RBCs in the synthesis of NO and will be of help for studies assessing the involvement of these cells in the regulation of blood flow under physiologic or pathological conditions. Moreover, a simple sample processing without the derivatization step, allows to consider this method a valuable tool for diagnostic evaluation of arginine metabolome in red blood cells and it could be applied in clinical chemistry
Plasma dimethylarginines in patients with coronary artery disease and renal insufficiency
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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