References of "Pincemail, Joël"
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See detailSample dilution influences the determination of antioxidant capacity in food. How to minimize it?
Sipel, Arnaud; Kevers, Claire ULg; PINCEMAIL, Joël ULg et al

in Food Analytical Methods (2013), 6(5), 1485-1491

The influence of sample dilution on the measurement of antioxidant capacity was analyzed. To ensure the reproducibility of results it is necessary to realize such scarce investigations. This study focuses ... [more ▼]

The influence of sample dilution on the measurement of antioxidant capacity was analyzed. To ensure the reproducibility of results it is necessary to realize such scarce investigations. This study focuses on different antioxidant capacity assays, commonly used for the analysis of pure substances and food extracts. For all compounds and foods tested in most of the four assays (TEAC, DPPH and ORAC), effects of sample dilution on the measured (and recalculated) antioxidant capacity were observed, differences up to 28% between dilutions. An extrapolation method was proposed to obtain a “real value” thus to minimize the effects of the sample dilution. This extrapolation method is relatively simple, based on a linear regression of 4 or 5 appropriate dilutions of the sample and applicable to the various assays. The use of such a method will improve the consistency of inter-laboratory antioxidant capacity data and thus permit better comparisons. In contrast, there was no dilution problem with FRAP assays. [less ▲]

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See detailStress oxydant, anti-oxydants et vieillissement
Pincemail, Joël ULg; Petermans, Jean ULg

Conference (2012, April 26)

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See detailExtraction conditions can greatly influence antioxidant capacity assays in plant food matrices
Michiels, Jean-Albert ULg; Kevers, Claire ULg; Pincemail, Joël ULg et al

in Food Chemistry (2012), 130

The estimated antioxidant capacity of different matrices can vary considerably between research reports. Besides intrinsic factors (not studied here), our work showed that may have various causes. Firstly ... [more ▼]

The estimated antioxidant capacity of different matrices can vary considerably between research reports. Besides intrinsic factors (not studied here), our work showed that may have various causes. Firstly, different methods are used to measure antioxidant capacity. Secondly, the results obtained for a single matrix by one method (such as ORAC) can vary with the extraction conditions. Parameters having a great impact on the amount and composition of antioxidants in extracts, and thus on the measured antioxidant capacity, notably include the extraction solvent composition, temperature, extraction time (duration), solvent-to-solid ratio, and storage conditions. Standardization of the extraction procedure is thus necessary for accurate and reproducible determination of the antioxidant capacity and phenolics in different food matrices by different laboratories. In this study we optimised such a procedure for four fresh plant matrices (orange, apple, leek, and broccoli). The optimised procedure requires extraction in a mixture of acetone/water/acetic acid (70/28/2, v/v/v) for 1 h at 4°C, with a solvent-to-solid ratio of 20 mL per 1 g. Fresh material should be used, but if this is not possible, one may lyophilise the plant matrices or store the extracts for a few days at -20°C before analysis. [less ▲]

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See detailOn the potential increase of the oxidative stress status in patients with abdominal aortic aneurysm.
PINCEMAIL, Joël ULg; Defraigne, Jean-Olivier ULg; Cheramy-Bien, J. P. et al

in Redox Report : Communications in Free Radical Research (2012), 17(4), 139-44

BACKGROUND: Abdominal aortic aneurysm (AAA) is a major cause of preventable deaths in older patients. Oxidative stress has been suggested to play a key role in the pathogenesis of AAA. However, only few ... [more ▼]

BACKGROUND: Abdominal aortic aneurysm (AAA) is a major cause of preventable deaths in older patients. Oxidative stress has been suggested to play a key role in the pathogenesis of AAA. However, only few studies have been conducted to evaluate the blood oxidative stress status of AAA patients. METHODS AND RESULTS: Twenty seven AAA patients (mean age of 70 years) divided into two groups according to AAA size (</= 50 or > 50 mm) were compared with an age-matched group of 18 healthy subjects. Antioxidants (vitamins C and E, beta-carotene, glutathione, thiols, and ubiquinone), trace elements (selenium, copper, zinc, and copper/zinc ratio) and markers of oxidative damage to lipids (lipid peroxides, antibodies against oxidized patients, and isoprostanes) were measured in each subject. The comparison of the three groups by ordinal logistic regression showed a significant decrease of the plasma levels of vitamin C (P = 0.011), alpha-tocopherol (P = 0.016) but not when corrected for cholesterol values, beta-carotene (P = 0.0096), ubiquinone (P = 0.014), zinc (P = 0.0035), and of selenium (P = 0.0038), as AAA size increased. By contrast, specific markers of lipid peroxidation such as the Cu/Zn ratio (P = 0.046) and to a lesser extent isoprostanes (P = 0.052) increased. CONCLUSION: The present study emphasizes the potential role of the oxidative stress in AAA disease and suggests that an antioxidant therapy could be of interest to delay AAA progression. [less ▲]

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See detailAntioxidant and anti-inflammatory activities of Ribes nigrum extracts.
Tabart, Jessica ULg; Franck, Thierry ULg; Kevers, Claire ULg et al

in Food Chemistry (2012), 131(4), 1116-1122

Blackcurrant berries contain high amounts of flavonoids with various health benefits as anti-inflammatory properties attributed to their antioxidant potential. Leaves and buds actually used to produce ... [more ▼]

Blackcurrant berries contain high amounts of flavonoids with various health benefits as anti-inflammatory properties attributed to their antioxidant potential. Leaves and buds actually used to produce food supplement could also exhibit such interesting properties. <br />In the literature, various methods are often used and valid indicators of the antioxidant potential of dietary substances. However these assays do not provide evidence that antioxidants have in vivo or ex vivo activity when consumed. To obtain biologically relevant information, the antioxidant activities of the extracts were evaluated on cellular models implicating the measurement of blood haemolysis, the Cellular Antioxidant Activity on endothelial cells and the anti-inflammatory activities on isolated equine stimulated neutrophils and purified myeloperoxidase. <br />These tests generally showed that the blackcurrant leaf extract have the highest antioxidant and <br />anti-inflammatory (inhibition of MPO activity and ROS production on activated neutrophils) capacities correlated to the highest total phenolics content. [less ▲]

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See detailFunctional muscle impairment in facioscapulohumeral muscular dystrophy is correlated with oxidative stress and mitochondrial dysfunction.
Turki, Ahmed; Hayot, Maurice; Carnac, Gilles et al

in Free Radical Biology & Medicine (2012), 53(5), 1068-79

Facioscapulohumeral muscular dystrophy (FSHD), the most frequent muscular dystrophy, is an autosomal dominant disease. In most individuals with FSHD, symptoms are restricted to muscles of the face, arms ... [more ▼]

Facioscapulohumeral muscular dystrophy (FSHD), the most frequent muscular dystrophy, is an autosomal dominant disease. In most individuals with FSHD, symptoms are restricted to muscles of the face, arms, legs, and trunk. FSHD is genetically linked to contractions of the D4Z4 repeat array causing activation of several genes. One of these maps in the repeat itself and expresses the DUX4 (the double homeobox 4) transcription factor causing a gene deregulation cascade. In addition, analyses of the RNA or protein expression profiles in muscle have indicated deregulations in the oxidative stress response. Since oxidative stress affects peripheral muscle function, we investigated mitochondrial function and oxidative stress in skeletal muscle biopsies and blood samples from patients with FSHD and age-matched healthy controls, and evaluated their association with physical performances. We show that specifically, oxidative stress (lipid peroxidation and protein carbonylation), oxidative damage (lipofuscin accumulation), and antioxidant enzymes (catalase, copper-zinc-dependent superoxide dismutase, and glutathione reductase) were higher in FSHD than in control muscles. FSHD muscles also presented abnormal mitochondrial function (decreased cytochrome c oxidase activity and reduced ATP synthesis). In addition, the ratio between reduced (GSH) and oxidized glutathione (GSSG) was strongly decreased in all FSHD blood samples as a consequence of GSSG accumulation. Patients with FSHD also had reduced systemic antioxidative response molecules, such as low levels of zinc (a SOD cofactor), selenium (a GPx cofactor involved in the elimination of lipid peroxides), and vitamin C. Half of them had a low ratio of gamma/alpha tocopherol and higher ferritin concentrations. Both systemic oxidative stress and mitochondrial dysfunction were correlated with functional muscle impairment. Mitochondrial ATP production was significantly correlated with both quadriceps endurance (T(LimQ)) and maximal voluntary contraction (MVC(Q)) values (rho=0.79, P=0.003; rho=0.62, P=0.05, respectively). The plasma concentration of oxidized glutathione was negatively correlated with the T(LimQ), MVC(Q) values, and the 2-min walk distance (MWT) values (rho=-0.60, P=0.03; rho=-0.56, P=0.04; rho=-0.93, P<0.0001, respectively). Our data characterized oxidative stress in patients with FSHD and demonstrated a correlation with their peripheral skeletal muscle dysfunction. They suggest that antioxidants that might modulate or delay oxidative insult may be useful in maintaining FSHD muscle functions. [less ▲]

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See detailCultivars, culture conditions and harvest time influence phenolic and ascorbic acid contents and antioxidant capacity of strawberry (Fragaria x ananassa)
Pincemail, Joël ULg; Kevers, Claire ULg; Tabart, Jessica ULg et al

in Journal of Food Science (2012), 77

Strawberries are a good source of micronutrients, especially antioxidant phenolics. More information is needed to better exploit the health-promoting effect of such fruits. Several studies focused on the ... [more ▼]

Strawberries are a good source of micronutrients, especially antioxidant phenolics. More information is needed to better exploit the health-promoting effect of such fruits. Several studies focused on the effects of genotype, cultural practices and seasonal variation on the antioxidant potential of strawberries, but often yielding contradictory results and/or focusing on only one source of variability. In the present study, we showed that total phenolic compounds, ascorbic acid and antioxidant capacity strongly differed between genotypes of strawberry. The precise results revealed the importance of genetic background for the antioxidant capacity and for the content of total phenolics (with up to 3.3-fold variations). Other parameters may also influence the antioxidant capacity in strawberry such as harvest time, culture conditions and environmental factors. Moreover, in this study, the harvesting time (at the same ripening stage) appeared to be very important, more important than genotype. Variations of the antioxidant capacity of up to 4.1-folds were observed following the harvesting time of “Elsanta” cultivar. [less ▲]

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See detailEvidence of health benefits of of polyphenols enriched foods : from In Vitro studies to clinical trials performed at university - CHU of Liège, Belgium
PINCEMAIL, Joël ULg; Kevers, Claire ULg; Tabart, Jessica ULg et al

in University of Ferrara (Ed.) Second Internaional conference on environmental stressors in biology and medicine (2011, October)

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See detailIncreased oxidative stress status is associated with abdominal aortic aneurysm
PINCEMAIL, Joël ULg; Defraigne, Jean-Olivier ULg; Albert, Adelin ULg et al

in University of Ferrara (Ed.) Second Internaional conference on environmental stressors in biology and medicine (2011, October)

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See detailFatty acids determinations: an cardiovascular risk? Preliminary results
LE GOFF, Caroline ULg; Leroy, Ludovic; Pincemail, Joël ULg et al

in Biomedica - Life Science Summit (2011, April 07)

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See detailConsequences of Pneumoperitoneum on Liver Ischemia During Laparoscopic Portal Triad Clamping in a Swine Model.
Nsadi, Berthier; Gilson, Nathalie ULg; Pire, Emilie et al

in Journal of Surgical Research (2011), 166(1), 35-43

BACKGROUND: Portal triad clamping (PTC) may be required during laparoscopic liver resection to limit blood loss. The aim of this study was to test in a swine model the hypothesis that during laparoscopic ... [more ▼]

BACKGROUND: Portal triad clamping (PTC) may be required during laparoscopic liver resection to limit blood loss. The aim of this study was to test in a swine model the hypothesis that during laparoscopic PTC, increased intraperitoneal pressure may alter hepatic vein reverse circulation, inducing a more severe hepatic ischemia compared with PTC performed in laparotomy. METHODS: Fifteen pigs were randomized into three groups: laparoscopy (1 h of pneumoperitoneum at 15 mmHg and 3 h of surveillance), open PTC (1 h PTC through laparotomy and 3 h of reperfusion), and laparoscopic PTC (1 h PTC with 15 mmHg pneumoperitoneum and 3 h of reperfusion). PTC was performed under mesenteric decompression using a veno-venous splenofemoral bypass. Hepatic partial oxygen tension and microcirculatory flow were continuously measured using a Clarke-type electrode and a laser Doppler flow probe, respectively. Liver consequences of PTC was assessed by right atrium serum determination of transaminases, creatinine, bilirubin, INR, and several ischemia/reperfusion parameters, drawn before PTC (T0), before unclamping (T60), and 1 (T120) and 3 h after reperfusion (T240). Histology was performed on T240 liver biopsies. RESULTS: Compared with open PTC, laparoscopic PTC produced a more rapid and more severe decrease in hepatic oxygen tension, indicating a more severe tissular hypoxia, and a more severe decrease in hepatic microcirculatory flow, indicating a decrease in hepatic backflow. At T240, the laparoscopic PTC livers suffered from a higher degree of hepatocellular damage, shown by higher transaminases and increased necrotic index at pathology. CONCLUSIONS: These results indicate that in this pig model, laparoscopic PTC induces a more severe liver ischemia, related to decreased hepatic oxygen content and decreased hepatic backflow. If confirmed by clinical studies, these results may indicate that caution is necessary when performing prolonged PTC during laparoscopic hepatic resection, particularly in cirrhotic or steatotic livers. [less ▲]

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See detailLifestyle Behaviours and Plasma Vitamin C and β-Carotene Levels from ELAN Population (Liège, Belgium)
PINCEMAIL, Joël ULg; Vanbelle, Sophie ULg; Degrune, Fabien et al

in Journal of Nutrition and Metabolism (2011), 2011

Several factors, including fruit and vegetables intakes, have been shown to significantly influence the plasma concentrations of the two antioxidants vitamin C and β-carotene. Deficiency levels of 6 mg/L ... [more ▼]

Several factors, including fruit and vegetables intakes, have been shown to significantly influence the plasma concentrations of the two antioxidants vitamin C and β-carotene. Deficiency levels of 6 mg/L (34.2 μM) for vitamin C and of 0.22 mg/L (0.4 μM) for β-carotene have been suggested below which cardiovascular risk might be increased. The present study performed on 897 presumably healthy subjects aged 40–60 years aimed to examine how modifiable lifestyle factors may be related to vitamin C and/or β-carotene deficiency. Gender, smoking, lack of regular physical activity and of daily fruit consumption (≥2/day), and social status (in particular, unemployment) were found to be significant risk factors for vitamin C deficiency. For β-carotene deficiency, the same factors were identified except social status; moreover, overweight and OC use in women were also found to have a deleterious effect. For non exposed subjects, the probability of developing vitamin C deficiency was 4% in men and 2.4% in women. This probability increased to 66.3% for men and to 44.3% for women (and even to 50.4% under OC use), when all risk factors were present. For β-carotene deficiency, the corresponding probabilities were equal to 29.7% in men and 13.7% in women (no risk factor present), and to 86.1% for men and 69.9% (91.6% for OC use) for women (all factors present), respectively [less ▲]

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See detailInfluence of cultivar, harvest time, storage conditions, and peeling on the antioxidant capacity and phenolic and ascorbic acid contents of apples and pears."
Kevers, Claire ULg; PINCEMAIL, Joël ULg; Tabart, Jessica ULg et al

in Journal of Agricultural and Food Chemistry (2011), 59

Apple and pear fruits are important sources of secondary plant metabolites and one of the major sources of dietary phenolics consumed all year round. The aim of this work was to identify the main ... [more ▼]

Apple and pear fruits are important sources of secondary plant metabolites and one of the major sources of dietary phenolics consumed all year round. The aim of this work was to identify the main variables influencing phenolic content and antioxidant capacity in apples. Higher phenolic and antioxidant contents were observed in some varieties (such as the Delbar Estival apple and Durondeau pear). Storage conditions were important. Our results also showed that fruits should be consumed rapidly after purchase and with their peel. After one week of domestic storage, the ascorbic acid content was found to decrease by 75%. Peeling led to a more than 25% decrease in total phenolics and ascorbic acid. The harvest time (at normal ripeness) had only a limited impact, but significant year-to-year variations were observed. In conclusion, well-chosen and well-stored apples and pears may contribute to an antioxidant-rich diet if consumed rapidly and with their peel. [less ▲]

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See detailConsequences of laparoscopy on liver ischemia during portal triad clamping in a swine model
Nsadi, Berthier; Pire, E.; Gilson, Nathalie ULg et al

in Acta Chirurgica Belgica (2010, April), 110

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See detailOxidative Stress in the Cochlea: An Update.
Poirrier, Anne-Lise ULg; Pincemail, Joël ULg; Van Den Ackerveken, P. et al

in Current Medicinal Chemistry (2010)

This paper will focus on understanding the role and action of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the molecular and biochemical pathways responsible for the regulation of ... [more ▼]

This paper will focus on understanding the role and action of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the molecular and biochemical pathways responsible for the regulation of the survival of hair cells and spiral ganglion neurons in the auditory portion of the inner ear. The pivotal role of ROS/RNS in ototoxicity makes them potentially valuable candidates for effective otoprotective strategies. In this review, we describe the major characteristics of ROS/RNS and the different oxidative processes observed during ototoxic cascades. At each step, we discuss their potential as therapeutic targets because an increasing number of compounds that modulate ROS/RNS processing or targets are being identified. [less ▲]

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See detailEvaluation of spectrophotometric methods for antioxidant compound measurement in relation to total antioxidant capacity in beverages.
Tabart, Jessica ULg; Kevers, Claire ULg; Pincemail, Joël ULg et al

in Food Chemistry (2010), 120

The validity of different colorimetric methods used to quantify various families of antioxidant compounds was evaluated with standard compounds. The colorimetric tests for global evaluation of flavonoids ... [more ▼]

The validity of different colorimetric methods used to quantify various families of antioxidant compounds was evaluated with standard compounds. The colorimetric tests for global evaluation of flavonoids, anthocyans, and flavanols were found generally unreliable, as reactions could be different for individual compounds within a family (anthocyanins or flavonols or flavan-3-ols) and not specific to one family. In the flavonoid test, for example, flavonols reacted very well, anthocyanins did not react, and flavanons reacted only slightly. The same methods were applied also to beverages known for their antioxidant content (apple, orange, grape, and vegetable juices, ice tea, and red wine) and the data were compared with the results of HPLC analysis of specific compounds. The values obtained in a colorimetric test were generally higher than the sum of the values obtained for the corresponding individual compounds by HPLC analysis, mainly because other compounds can interfere with the colorimetric tests. For example, in wine, anthocyanin concentrations obtained by colorimetric test were 9068  1407 µ mol /100ml (mean  SEM), higher than the sum of the six main anthocyanidins detected by HPLC, only 41 µmol/100 ml. The relative antioxidant capacity values determined for beverages on the basis of colorimetric tests could exceed by far the values previously measured in radical-scavenging tests (for instance, the antioxidant capacity attributable to anthocyans in wine on the basis of the colorimetric test was 50 times higher than the total antioxidant capacity measured by the ORAC assay). In conclusion, colorimetric tests for flavonoids, anthocyans, and flavanols appeared generally unreliable for estimating their content and thus the antioxidant capacity reliable to these compounds. [less ▲]

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See detailConsequences of laparoscopy on liver ischemia during portal triad clamping in a swine model
Gilson, Nathalie ULg; Nsadi, Berthier; Pire, E. et al

in Acta Gastro-Enterologica Belgica (2010), 73(1), 13

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See detailLe pneumopéritoine aggrave l'ischémie hépatique lors du clampage hilaire dans un modèle porcin
Nsadi, Berthier; Gilson, Nathalie; Pire, E. et al

in Journal de Chirurgie (2009, December), 146

Detailed reference viewed: 73 (21 ULg)