Publications by authors named "Jean-Claude Guilland"

Aims: To study how MTHFR 677C→T genotype modulates the effect of supplementation with B-vitamins on total homocysteine (tHcy) and B-vitamin concentrations.

Methods: 2381 patients with a personal history of cardiovascular disease were randomly assigned to one of four groups: 1) B-vitamins alone (560 μg of 5-methyl-THF, 3 mg of vitamin B6 and 20 μg of vitamin B12), 2) n-3 fatty acids alone (600 mg of EPA and DHA in a 2:1 ratio), 3) B-vitamins and n-3 fatty acids, and 4) placebo. Participants were followed up for 4.

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Objectives: We aimed to investigate whether SDMA- symmetric dimethylarginine -the symmetrical stereoisomer of ADMA- might be a marker of left ventricular function in AMI.

Background: Asymmetric dimethylarginine (ADMA) has been implicated in the prognosis after acute myocardial infarction (AMI) and heart failure (HF).

Methods: Cross sectional prospective study from 487 consecutive patients hospitalized <24 hours after AMI.

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Background: The prevalence of 25-hydroxyvitamin D [25(OH)D] deficiency is high in patients presenting with an acute stroke, and it may be associated with greater clinical severity and a poor early functional prognosis. However, no data about its impact on long-term prognosis is available. In this study, we aimed to assess the association between 25(OH)D levels and 1-year mortality in stroke patients.

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Article Synopsis
  • The study investigated how substrate availability affects fuel selection during exercise in endurance-trained cyclists, comparing performance in rested and fatigued conditions.
  • Eight male cyclists completed a 90-minute exercise session while measuring lipid oxidation and lipolysis after ingesting sucrose.
  • Results indicated that endurance exercise increases fat oxidation and influences fuel selection, emphasizing the importance of lipolysis and free fatty acid availability for effective fat utilization during physical activity.
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[Vitamin D].

Rev Prat

October 2013

Article Synopsis
  • Recent interest in vitamin D has emerged due to its hormone-like effects on overall health.
  • While earlier studies hinted at a connection between low vitamin D levels and an increased risk of chronic diseases, new research shows mixed results.
  • Future randomized intervention studies are needed to establish clear guidelines for optimal vitamin D levels, particularly for calcium balance and bone health.
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  • Vitamin B12 consists of four cobalamins, including methyl-Cbl and adenosyl-Cbl, which are essential co-factors for important enzymes in the body.
  • A deficiency in vitamin B12 can lead to significant health issues, primarily megaloblastic anemia and various neurological problems.
  • The diagnosis of vitamin B12 deficiency has advanced through additional tests measuring substances like serum methylmalonic acid and homocysteine, sparking debate about the clinical importance of low B12 levels without symptoms.
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  • - Vitamin B9, also known as folate, is derived from folic acid and plays a crucial role in various biological processes, particularly in methylation reactions and one-carbon unit transfers.
  • - It is vital for converting homocysteine into methionine, a process that relies on vitamin B12, and is involved in synthesizing important biomolecules like purines and pyrimidines.
  • - A deficiency in folate can lead to several health issues, such as high levels of homocysteine, megaloblastic anemia, increased risk of cardiovascular disease, neural tube defects in embryos, and potential links to depression and cognitive decline.
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  • - Vitamin B1 (thiamine) is essential for energy production from glucose, crucial for the proper functioning of the nervous system.
  • - A deficiency in thiamine can lead to serious neurological issues, and doctors measure thiamine status by examining thiamine pyrophosphate levels or transketolase activity in red blood cells.
  • - Severe thiamine deficiency is often seen in chronic alcoholics, those with prolonged vomiting during pregnancy, and after bariatric surgery, while mild deficiencies appear common but their effects are not well understood.
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In industrialized countries, the major vitamin deficiency syndromes have virtually disappeared. Today they are superseded by marginal deficits, characterized by insufficient vitamins reserves to maintain normal physiologic state. These states strike populations such as infants, pregnant women, alcoholics and the elderly, and may have long-term adverse effects on health.

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Background: Several recent studies have shown some discrepancies between 25-hydroxyvitamin D [25(OH)D] assay methods, despite some improvement in the past few years. The accuracy of 25(OH)D assay methods is still a real challenge for clinical laboratories. The aim of this study was to assess the agreement between a large panel of routine assays and a two-dimensional liquid chromatography/tandem mass spectrometry (2D LC-MS/MS) method, selected as the reference method.

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Nitric oxide (NO) is synthetized enzymatically from l-arginine (l-Arg) by three NO synthase isoforms, iNOS, eNOS and nNOS. The synthesis of NO is selectively inhibited by guanidino-substituted analogs of l-Arg or methylarginines such as asymmetric dimethylarginine (ADMA), which results from protein degradation in cells. Many disease states, including cardiovascular diseases and diabetes, are associated with increased plasma levels of ADMA.

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Objectives: Low levels of high-density lipoprotein (HDL) cholesterol are associated with an increased risk of acute myocardial infarction possibly through impaired endothelial atheroprotection and decreased nitric oxide (NO) bioavailability. Asymmetric dimethylarginine (ADMA) mediates endothelial function by inhibiting nitric oxide synthase activity. In patients with acute myocardial infarction, we investigated the relationship between serum levels of HDL and ADMA.

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L-Arginine (L-Arg) is a conditionally essential amino acid in the human diet. The most common dietary sources of L-Arg are meat, poultry and fish. L-Arg is the precursor for the synthesis of nitric oxide (NO); a key signaling molecule via NO synthase (NOS).

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Background: Even though it has been suggested that antiretroviral therapy has an impact on severe hypovitaminosis D (SHD) in HIV infected patients, it could be speculated that the different levels of residual inflammation on HAART (Highly Active Anti Retroviral Therapy) could contribute to SHD and aggravate bone catabolism in these patients.

Methods: A cross-sectional study was carried out in an unselected cohort of 263 HIV infected outpatients consulting during Spring 2010. Clinical examinations were performed and medical history, food habits, sun exposure and addictions were collected.

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In contrast to the masses of data on obesity, few data are available concerning the cardiometabolic and oxidative consequences of moderate overweight. The model of postnatal overfeeding (OF) induces an increase in body weight at weaning that remains during adult life. Litters of Wistar rats were either maintained at 12 pups (normal-fed group, NF), or reduced to 3 pups at birth in order to induce OF.

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The molecular mechanisms underlying doxorubicin (DOX)-induced cardiomyopathy include alterations in cardiomyocytes' oxidative stress status and in gene expression. Although such alterations have been reported during in vivo DOX treatment of animals, it remains to be clarified whether they persist after treatment cessation. To address this question, rats were injected with either saline (1 ml/kg/day i.

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To evaluate the effects of alpha-lipoic acid (AL) in a model of doxorubicin (DOX)-induced cardiotoxicity, male Wistar rats were treated with DOX (1 mg/kg/d; 10 d) in combination or not with AL (50 mg/kg/d; 15 d). Plasma oxidative stress was determined by hydroperoxides (ROOH) and the ascorbyl radical/ascorbate ratio. One and two months later, the functional parameters of the hearts were determined in vivo by catheterization and cardiac oxidative stress was assessed by malonedialdehyde (MDA) and O₂*⁻ (dihydroethidium fluorescence) content in tissue.

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The goal of this study is to determine whether cardiovascular risk and the methylenetetrahydrofolate reductase 677 C->T polymorphism (MTHFR), an enzyme involved in folate metabolism and in epigenetics, are linked in morbidly obese non-diabetic adolescents. One-hundred and thirteen obese (BMI = 39.1 ± 6.

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Fat oxidation (FO) is optimized during low- to moderate-intensity exercise in lean and obese subjects, whereas high-intensity exercise induces preferential FO during the recovery period. After food intake during the postexercise period, it is unknown if FO differs according to the intensity exercise in overweight subjects. Fat oxidation was thus evaluated in overweight men after low- and high-intensity exercise during the recovery period before and after food intake as well as during a control session.

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This study was designed to evaluate the effects of individual dietary long-chain n-3 polyunsaturated fatty acids (LCPUFA) on hypertension and cardiac consecutive disorders in spontaneously hypertensive rats (SHR) as compared to Wistar-Kyoto rats (WKY). Rats were fed for 2 months an eicosapentaenoic (EPA)- or docosahexaenoic acid (DHA)-rich diet (240 mg/day) or an n-3 PUFA-free diet. Male SHR (n=6), implanted with cardiovascular telemetry devices, were housed in individual cages for continuous measurements of cardiovascular parameters (blood pressure (BP) and heart rate (HR)) during either activity or rest periods, ECG were recorded during the quiet period.

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Article Synopsis
  • * Researchers measured levels of ascorbyl free radical (a marker of oxidative stress) and catecholamines before and after dialysis, finding that the oxidative stress ratio increased after dialysis but catecholamine levels remained unchanged.
  • * Ultimately, the results suggest that while vitamin C and norepinephrine could be involved in cardiovascular issues, they do not appear to directly influence each other in patients with end-stage renal disease.
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Severe septic states in humans are responsible for intense intravascular oxidative stress, which induces numerous adaptive mechanisms. We determined time sequence changes in total plasma antioxidant capacity (TAC) and major plasma antioxidant concentrations, which have not been fully explained in septic conditions. A cohort of 56 consecutive septic patients (septic shock n = 37, severe sepsis n = 19) and six healthy volunteers.

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Among their pleiotropic effects, statins exert antioxidant and anti-inflammatory properties. The aim of this study was to evaluate in normotensive (WKY) and in spontaneously hypertensive rats (SHR) the effect of rosuvastatin (ROSU) treatment on (1) plasma inflammation markers and endogenous NO synthase inhibitor (ADMA) levels, (2) reactive oxygen species (ROS) generated by circulating leukocytes and (3) vascular oxidative stress and tissue inflammation markers. Plasma cytokines were higher in SHR than in WKY, except for IL-4, which was lower in SHR than in WKY.

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