Association between D-Dimer levels and mortality in patients with coronavirus disease 2019 (COVID-19): a systematic review and pooled analysis.

BACKGROUND: Several observational studies have reported elevated baseline D-dimer levels in patients hospitalized for moderate to severe coronavirus disease 2019 (COVID-19). These elevated baseline D-dimer levels have been associated with disease severity and mortality in retrospective cohorts. OBJECTIVES: To review current available data on the association between D-Dimer levels and mortality in patients admitted to hospital for COVID-19. METHODS: We performed a systematic review of published studies using MEDLINE and EMBASE through 13 April 2020. Two authors independently screened all records and extracted the outcomes. A random effects model was used to estimate the standardized mean difference (SMD) with 95% confidence intervals (CI). RESULTS: Six original studies enrolling 1355 hospitalized patients with moderate to critical COVID-19 (391 in the non-survivor group and 964 in the survivor group) were considered for the final pooled analysis. When pooling together the results of these studies, D-Dimer levels were found to be higher in non-survivors than in-survivors. The SMD in D-Dimer levels between non-survivors and survivors was 3.59µg/L (95% CI 2.79-4.40µg/L), and the Z-score for overall effect was 8.74 (P<0.00001), with a high heterogeneity across studies (I2=95%). CONCLUSIONS: Despite high heterogeneity across included studies, the present pooled analysis indicates that D-Dimer levels are significantly associated with the risk of mortality in COVID-19 patients. Early integration of D-Dimer testing, which is a rapid, inexpensive, and easily accessible biological test, can be useful to better risk stratification and management of COVID-19 patients.

Lipoprotein-associated phospholipase A2 activity is increased in patients with definite familial hypercholesterolemia compared with other forms of hypercholesterolemia.

BACKGROUND AND AIM: Lipoprotein-associated phospholipase A2 (Lp-PLA2) plays a key role in atherosclerosis development. It is considered a marker of increased risk of cardiovascular disease (CVD) and plaque vulnerability. Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated plasma levels of low-density lipoprotein cholesterol and a higher prevalence of early CVD. Our aim was to evaluate the differences in Lp-PLA2 activity in a population of hypercholesterolemic patients with and without definite FH. METHODS AND RESULTS: Hypercholesterolemic patients were consecutively recruited. Definite FH was defined according to Dutch Lipid Clinic Network criteria ≥8. All patients underwent routine clinical examination and biological assessments and Lp-PLA2 activity was measured in blood samples. Among 469 patients, 118 had a definite diagnosis of FH. Lp-PLA2 activity was significantly higher in definite FH patients compared to non-definite FH patients (206.5 ± 54.5 vs. 180.8 ± 48.4 nmol/min/mL, p < 0.0001). Lp-PLA2 positively correlated with total cholesterol, LDL-C and apolipoprotein B and negatively with HDL-C and apolipoprotein A-1. In multivariate analysis, definite FH diagnosis, LDL-C, HDL-C and statin treatment remained correlates of Lp-PLA2 independently of systolic blood pressure. CONCLUSIONS: Lp-PLA2 activity was higher in definite FH than in non-definite FH patients independently of LDL-C levels and statin treatment. These results highlight the particular phenotype of FH subjects among hypercholesterolemic patients. As increased Lp-PLA2 activity suggests, FH patients exhibit higher arterial inflammation that may contribute to their high cardiovascular risk. Our results reinforce the potential beneficial role of statins pleiotropic effects and the need for proper identification and treatment of FH patients.

Oxidative stress and the amyloid beta peptide in Alzheimer's disease.

Oxidative stress is known to play an important role in the pathogenesis of a number of diseases. In particular, it is linked to the etiology of Alzheimer's disease (AD), an age-related neurodegenerative disease and the most common cause of dementia in the elderly. Histopathological hallmarks of AD are intracellular neurofibrillary tangles and extracellular formation of senile plaques composed of the amyloid-beta peptide (Aß) in aggregated form along with metal-ions such as copper, iron or zinc. Redox active metal ions, as for example copper, can catalyze the production of Reactive Oxygen Species (ROS) when bound to the amyloid-ß (Aß). The ROS thus produced, in particular the hydroxyl radical which is the most reactive one, may contribute to oxidative damage on both the Aß peptide itself and on surrounding molecule (proteins, lipids, …). This review highlights the existing link between oxidative stress and AD, and the consequences towards the Aß peptide and surrounding molecules in terms of oxidative damage. In addition, the implication of metal ions in AD, their interaction with the Aß peptide and redox properties leading to ROS production are discussed, along with both in vitro and in vivo oxidation of the Aß peptide, at the molecular level.

Impact of pH on Urine Chemistry Assayed on Roche Analyzers.

BACKGROUND: The pH may impact the concentration of certain urinary parameters, making urine pre-treatment questionable. METHODS: 1) Determining the impact of pH in vitro on the urinary concentration of chemistry parameters assayed on Roche Modular analyzers. 2) Evaluating whether concentrations depended on pH in non-pretreated urines from patients. RESULTS: 1) The optimal urinary pH values for each measurement were: 6.3 ± 0.8 (amylase), < 5.5 (calcium and magnesium), < 6.5 (phosphorus), > 6.5 (uric acid). Urinary creatinine, sodium and urea concentrations were not pH-dependent. 2) In urines from patients, the pH was negatively associated with the concentration of some urinary parameters. However, concentrations of all the parameters were strongly and positively correlated with urinary creatinine, and relationships with pH were no longer evidenced after creatinine-normalization. CONCLUSIONS: The need for urine pH adjustment does not seem necessary when considering renal function. However, from an analytical and accreditation standpoint, the relationship between urine pH and several parameters justifies its measurement.

[Lp-PLA2, a biomarker of vascular inflammation and vulnerability of atherosclerosis plaques]. / La Lp-PLA2, marqueur d'inflammation vasculaire et de vulnérabilité de la plaque d'athérosclérose.

A chronic inflammation is involved in various stages of development of the atherosclerotic plaques. Among the emerging biomarkers of atherogenesis, the lipoprotein-associated phospholipase A2 (Lp-PLA2), formerly known as PAF-acetylhydrolase (McIntyre et al., 2009), hydrolyses the oxidized short chain phospholipids of low-density lipoproteins (LDL), thereby releasing pro-inflammatory mediators (lysophospholipids and oxidized fatty acids). Lp-PLA2, produced by monocytes/macrophages and T-lymphocytes, and mainly associated with LDL (Gazi et al., 2005), is predominantly expressed in the necrotic center of the atherosclerotic plaques and in the macrophage-rich areas (Kolodgie et al., 2006). It would have a predictive role of cardiovascular (CV) events in relation to the vulnerability of atherosclerotic plaques. Determination of Lp-PLA2 has been proposed in the assessment of the CV risk, to ensure a better stratification of populations at intermediate risk for targeted therapy (Davidson et al., 2008). Its proatherogenic role suggested that inhibition of its activity could ensure a better vascular protection in combination with cholesterol-lowering agents. Nevertheless, Lp-PLA2 is not yet a fully validated marker for use in daily clinical practice, especially since the studies using an inhibitor of Lp-PLA2 (darapladib) (STABILITY Investigators et al., 2014; O'Donoghue et al., 2014) did not show any reduction in coronary events. Lp-PLA2 could have a site-specific role in plaque inflammation and development (Fenning et al., 2015). High Lp-PLA2 activity could reflect a response to pro-inflammatory stress characteristic of atherosclerosis (Marathe et al., 2014). This presentation aims at clarifying the involvement of Lp-PLA2 in the pathophysiology of atherosclerosis, and at assessing its interest both as a biomarker for the onset of CV events and as a therapeutic target.

Inter-relations between osteoarthritis and metabolic syndrome: A common link?

Osteoarthritis (OA) is a degenerative disorder of the joint, principally occurring during aging, and characterized by a focal degradation of cartilage. It is the most prevalent rheumatic disease in industrialized countries and represents the second cause of disability in France. However, the etiology of OA remains unclear. There is only one cell type found in cartilage, chondrocyte, which is responsible for its repair and the synthesis of the elements of the extra-cellular matrix. A dysfunction of these cells results in an imbalance between repair and degradation in cartilage, leading to its destruction. Recently, a link between OA and metabolic syndrome (MetS) has been suggested, introducing a notion of metabolic OA, and a new vision of the disease. MetS is characterized by a cluster of factors (insulin resistance, hypertension, dyslipidemia, visceral obesity), although there is still no clear definition of it. During the 20th century, MetS dramatically increased with changes in population lifestyle, becoming a major health issue in industrialized countries. MetS concerns 10-30% of the worldwide population, but is prevalent in 59% of OA patients. Patients with both OA and MetS have more severe symptoms, occurring sooner than in the general population. Indeed, OA is generally a disease concerning the population over 65 years old, but with an associated MetS the target population is around 50 years old. In this review, we will focus on common factors in OA and MetS, such as hypertension, obesity, dyslipidemia, mitochondrial dysfunction and hyperglycemia, linking one disease to the other.

Mechanism of one-electron oxidation of metformin in aqueous solution.

Hydroxyl free radical-induced oxidation of metformin was studied in aqueous solution as a function of the pH. Hydroxyl free radicals were generated by gamma radiolysis of water and the oxidation end-products were quantified by high-performance liquid chromatography coupled to mass spectrometry (HPLC/MS), as a function of the radiation dose. This work is a joint experimental and theoretical (DFT) approach that has paved the way towards a comprehensive rationalization of the one-electron mechanisms of MTF oxidation, as a function of the pH.

Effect of hypoxia/reoxygenation on the cytokine-induced production of nitric oxide and superoxide anion in cultured osteoarthritic synoviocytes.

OBJECTIVE: Hypoxia/reoxygenation (H/R) is an important feature in the osteoarthritis (OA) physiopathology. Nitric oxide (NO) is a significant proinflammatory mediator in the inflamed synovium. The purpose of this study was to investigate the effects of H/R on inducible NO synthase (iNOS) activity and expression in OA synoviocytes. In addition we studied the relationship between nitrosative stress and NADPH oxidase (NOX) in such conditions. METHODS: Human cultured synoviocytes from OA patients were treated for 24 h with interleukin 1-ß (IL-1ß), tumour necrosis factor α (TNF-α) or neither; for the last 6 h, they were submitted to either normoxia or three periods of 1-h of hypoxia followed by 1-h of reoxygenation. ·NO metabolism (iNOS expression, nitrite and peroxynitrite measurements) was investigated. Furthermore, superoxide anion O2(·-) production, NOX subunit expression and nitrosylation were also assessed. RESULTS: iNOS expression and nitrite (but not peroxynitrite) production were ~0.20 to ~0.12 nmol min(-1) mg proteins(-1) (P < 0.05), while NOXs' subunit expression and p47-phox phosphorylation were increased. NOXs and p47-phox were dramatically nitrosylated under H/R conditions (P < 0.05 vs normoxia). Using NOS inhibitors under H/R conditions, p47-phox nitrosylation was prevented and O2(·-) production was restored at normoxic levels (0.21 nmol min(-1) mg of proteins(-1)). CONCLUSIONS: Our results provide evidence for an up-regulation of iNOS activity in OA synoviocytes under H/R conditions, associated to a down-regulation of NOX activity through nitrosylation. These findings highlight the importance of radical production to OA pathogenesis, and appraise the metabolic modifications of synovial cells under hypoxia.

Interpretation of lipoprotein-associated phospholipase A2 levels is influenced by cardiac disease, comorbidities, extension of atherosclerosis and treatments.

PURPOSE: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an inflammatory biomarker secreted in the atherosclerotic plaque. Blood levels of Lp-PLA2 predict future cardiovascular events in patients with ischemic disease and heart failure. This association seems to be independent of traditional cardiovascular risk factors. The aims of our study were (1) to assess relationships between Lp-PLA2 levels, cardiac disease and treatments; (2) to evaluate the association of Lp-PLA2 level with the severity of angiographic coronary artery disease (CAD) and the extracoronary atherosclerosis. METHODS: Between December 2009 and June 2010, 494 subjects were recruited from a population scheduled for diagnostic coronary angiography. Routine clinical (age, gender, BMI and treatment), cardiac (echocardiography, coronarography, carotid ultrasonography) and biochemical parameters were recorded for all patients. Lp-PLA2 mass concentration was assessed in serum with a Plac®-test turbidimetric immunoassay. Control Lp-PLA2 values were specifically obtained in 61 healthy subjects aged 44.5 ± 17.6 years (range: 25 to 59 years) without known cardiovascular risk factors (diabetes, smoking, hypertension, dyslipidemia) or cardiac treatment. RESULTS: In healthy controls, mean Lp-PLA2 level was 163 ± 43 µg/L (166 ± 45 µg/L in men and 159 ± 39 µg/L in women, non significant difference). In our cohort of 494 patients (69.8% men) aged 64.2 ± 16.7 years, the main etiologies of cardiomyopathies were ischemic (40%), valvular (22%), cardiac failure with left ventricular (LV) dysfunction (14%), infection (5%) and aortic aneurysm (7%). Mean Lp-PLA2 levels were 216 ± 17 µg/L. Lp-PLA2 correlated with age, BMI, current smoking, history of hypertension but not with diabetes and gender. The bivariate analysis showed a significant correlation between Lp-PLA2, and BMI (p=0.001) but no correlation with serum creatinine or NYHA status. A multivariate correlation showed that Lp-PLA2 was associated with total cholesterol, LDL-cholesterol and apoB (r=0.95, p<0.0001) but not with Lp(a). We observed that Lp-PLA2 was significantly associated with treatments such as statins and ACEi/ARA2 but not with ß-blockers, antiaggregant drugs or diuretics. Lp-PLA2 levels were significantly higher in patients with CAD than in patients without CAD (223 ± 54 vs. 208 ± 52 µg/L, respectively; p<0.007). Moreover, Lp-PLA2 levels were significantly higher in patients with the most extensive angiographic CAD [single (n=24)=215.2 ± 52 µg/L; two (n=55)=222 ± 53 µg/L and three vessels (n=140)=251.9 ± 53.7 µg/L, respectively; p<0.0001]. Patients with heart failure, sepsis or aortic aneurysm had increased Lp-PLA2 levels: 256.2 ± 46.8; 226.7 ± 47.3; 218.1 ± 38.9 µg/L, respectively, as compared to controls (p<0.0001). In patients with carotid artery disease, Lp-PLA2 significantly increased with the severity of atherosclerosis. Mean Lp-PLA2 levels were 218.8 ± 51 µg/L in the group without any stenosis (n=108), 224 ± 51 µg/L in the group with mild stenosis (n=101), and 231 ± 46 µg/L in the group with severe stenosis (n=22); p=0.004. CONCLUSION: This study clearly shows that interpretation of Lp-PLA2 levels needs a good assessment of cardiac parameters and treatments, especially statins and ACEi/ARA2. Lp-PLA2 levels are significantly associated with coronary heart disease and with the extension of extra coronary disease after adjustment for age and gender.

Serum levels of adhesion molecules ICAM-1 and VCAM-1 and tissue inhibitor of metalloproteinases, TIMP-1, are elevated in patients with autoimmune thyroid disorders: relevance to vascular inflammation.

Serum levels of ICAM-1 (Inter Cellular Adhesion Molecule-1), VCAM-1 (Vascular cell Adhesion Molecule-1-I), TIMP-1 (tissue inhibitor of metalloproteinases 1) and MMP-9 (Metalloproteinase 9) are well established markers of inflammation. The physiopathological link between inflammation, atherosclerosis and autoimmunity is well demonstrated. However, serum levels of these biomarkers in patients with autoimmune-mediated dysthyroidism, including their evolution after improvement of the thyroid disorder have not been assessed. So, we evaluated the circulating levels of these markers in autoimmune and in non-autoimmune-mediated dysthyroid patients, and their evolution after treatment of thyroid disease. We conducted a prospective study to evaluate these markers before and after treatment in hyperthyroid patients (n = 33; 28 patients with autoimmune disease), hypothyroid patients (n = 38; 33 patients with autoimmune disease) and euthyroid subjects (n = 33). At baseline, serum levels of ICAM-1, VCAM-1 and TIMP-1 were significantly elevated in patients with hyperthyroidism as compared to euthyroid and hypothyroid patients (respectively p = 0.0005 and p < 0.0001). In multivariate analysis, the differences remained significant for VCAM-1 and TIMP-1. Median levels of ICAM-1, VCAM-1 and TIMP-1 were significantly higher in patients with autoimmune-mediated dysthyroidism compared to euthyroid patients (respectively p < 0.0001 and p = 0.002). In hyperthyroid patients, ICAM-1, VCAM-1 and TIMP-1 concentrations fell significantly after they had become euthyroid (respectively p = 0.0006; p < 0.0001 and p = 0.0009), although VCAM-1 values remained higher than those observed in the control group (p = 0.005). We found that autoimmune-mediated dysthyroidism were associated with increased peripheral blood concentrations of VCAM-1, ICAM-1 and TIMP-1. Whether these biological abnormalities translate into increase intima remodelling and atherosclerosis remains to be studied.

Manganese superoxide dismutase dimorphism relationship with severity and prognosis in cardiogenic shock due to dilated cardiomyopathy.

The aim was to determine (a) Ala-16Val-SOD2 dimorphisms; (b) allelic frequency and phenotype of a common Pro-Leu polymorphism in GPx1, in a cohort of patients with a cardiogenic shock (CS) due to dilated cardiomyopathy without acute coronary syndrome. Consecutive patients with de novo CS that worsened a dilated (DCM) or ischemic (ICM) cardiomyopathy. Congenital heart disease, pacemaker and other shock aetiologies were excluded. To determine oxidative stress (OS), this study evaluated lipid peroxidation, protein oxidation and erythrocyte GPx, SOD and catalase activities. Ala16Val-SOD2 (dbSNP: rs4880) and Pro198Leu-GPx1 (dbSNP: rs1050450) polymorphisms were studied by allelic discrimination using fluorogenic probes and the 5'nuclease (TaqMan) assay. Twenty-four patients (with ICM (n = 8) or DCM (n = 16), age = 57.5 ± 10.7 years, LVEF = 25.3 ± 8.5%, NT-proBNP levels = 8540 ± 1703 ng/L) were included during a 15 month follow-up. OS parameters were significantly higher in patients than in controls. Distribution of MnSOD genotypes was 47% Val/Val-variant, 29.5% Ala/Val and 23.5% Ala/Ala-variants. Severity of CS was more important in patients with Val/Val-variant and can be put in parallel with NT-proBNP levels (Val/Val-variant: 11 310 ± 3875 ng/L vs Ala/Ala-variant: 6486 ± 1375 ng/L and Ala/Val-variant: 6004 ± 2228 ng/L; p < 0.05) and hemodynamic support duration (144.6 vs Ala/Val-variant: 108.8 h and Ala/Ala-variant: 52.5 h; p < 0.05) with a positive correlation (Spearman rho = 0.72, p < 0.05). Moreover, Val/Val-variant significantly influenced the mortality (Spearman rho = 0.67, p < 0.05), but not the morbidity (p = 0.3). Distribution of GPx genotypes was 64% Pro/Pro, 18% Pro/Leu and 18% Leu/Leu. GPx-variants influenced neither GPx activities nor cardiac events. In conclusion, CS was associated with markers of increased OS. GPx polymorphism did not influence the GPx activity. Only the Val-encoding MnSOD allele was significantly correlated with the severity and prognosis of CS.

Switching the nucleoside reverse transcriptase inhibitor backbone to tenofovir disoproxil fumarate + emtricitabine promptly improves triglycerides and low-density lipoprotein cholesterol in dyslipidaemic patients.

OBJECTIVES: To assess the impact of switching to tenofovir disoproxil fumarate + emtricitabine on lipid parameters. METHODS: HIV-infected patients with plasma viral load <400 copies/mL, fasted triglycerides from 2.3 to 11.4 mmol/L and/or fasted low-density lipoprotein (LDL)-cholesterol >4.1 mmol/L were randomized to switch the nucleoside reverse transcriptase inhibitor (NRTI) backbone to fixed-dose combination tenofovir disoproxil fumarate + emtricitabine or to maintain the baseline antiretroviral regimen (the control group). The study has been registered with ClinicalTrials.gov under the identifier NCT00323492. RESULTS: Ninety-one patients were included in the intent-to-treat (ITT) analysis with triglycerides 2.4 mmol/L and LDL-cholesterol 4.0 mmol/L (median values). At week 12, the median changes from baseline of triglycerides were -0.5 mmol/L (-25%; n = 46) and -0.1 mmol/L (-6%; n = 45) in the tenofovir disoproxil fumarate + emtricitabine and control groups, respectively, indicating a difference of -0.4 mmol/L (P = 0.034) [95% confidence interval (CI): -0.9 to -0.0]. Similarly for LDL-cholesterol, changes of -0.4 mmol/L (-9%) and -0.1 mmol/L (-1%) were observed in the tenofovir disoproxil fumarate + emtricitabine and control groups, respectively, indicating a difference of -0.4 mmol/L (P = 0.031) [95% CI: -0.7 to -0.0]. The proportion of patients with LDL-cholesterol >4.1 mmol/L decreased from 48% at baseline to 26% at week 12 in the tenofovir disoproxil fumarate + emtricitabine group versus no change in the control group. No virological failure was observed during the study. CONCLUSIONS: Switching to tenofovir disoproxil fumarate + emtricitabine in dyslipidaemic HIV-infected patients improves triglycerides and LDL-cholesterol.

A machine-learning approach to the prediction of oxidative stress in chronic inflammatory disease.

Oxidative stress is implicated in the development of a wide range of chronic human diseases, ranging from cardiovascular to neurodegenerative and inflammatory disorders. As oxidative stress results from a complex cascade of biochemical reactions, its quantitative prediction remains incomplete. Here, we describe a machine-learning approach to the prediction of levels of oxidative stress in human subjects. From a database of biochemical analyses of oxidative stress biomarkers in blood, plasma and urine, non-linear models have been designed, with a statistical methodology that includes variable selection, model training and model selection. Our data demonstrate that, despite a large inter- and intra-individual variability, levels of biomarkers of oxidative damage in biological fluids can be predicted quantitatively from measured concentrations of a limited number of exogenous and endogenous antioxidants.

[Biomarkers of lipid peroxidation: analytical aspects]. / Biomarqueurs de la peroxydation lipidique: aspects analytiques.

During these last years, oxidative stress has been implicated in various pathological situations. The difficulty is to choose a convenient marker to appreciate its importance in vivo because of analytical problems of specificity and sensitivity. The oxidized lipids, formed during lipid peroxidation, illustrate these problems. Among these markers are 'primary' products such as hydroperoxides, or 'secondary' products such as malondialdéhyde (MDA), 4-hydroxynonénal (4-HNE) and isoprostanes. They are all measurable in biological fluids and analytical methods used are sometimes complex and require sample preparation involving extraction and purification steps. F2-isoprostanes are certainly the most specific markers of lipid peroxidation but also the most difficult to measure. Many assays have been recently developed. Some, such as gas or liquid chromatography coupled with mass spectrometry are the 'gold standard' methods, they allow to measure different F2-isoprostanes but require special apparatus. Others, like immunoassay methods measure one isoprostane, they are simpler to perform and accessible to a greater number of laboratories but still lack of specificity.

[Contribution of NMR to the assessment of dyslipidemia-related cardiovascular risk]. / Apport de la RMN dans l'évaluation du risque cardiovasculaire lié aux dyslipidémies.

Serum level of cholesterol bound to low density lipoproteins (LDL-cholesterol) is the basic parameter used to assess lipid-related cardiovascular risk. This parameter however underestimates the number of small dense LDLs that are especially atherogenic. A new analytic proposal is based on the determination of lipoproteinic profiles obtained by NMR (Liposcience, Raleigh, NC, United-States [Am J Cardiol 90 (2002) 22i-29i]; collaboration with M.J. Chapman, Inserm U551), that allows to quantify the number of atherogenic apo B-100-containing particles. This analysis is rapid, reproducible and does not require a previous separation of lipoproteins by ultracentrifugation. NMR signals come from the terminal methyl groups of lipids located in the envelope and the core of lipoproteins. Each lipoprotein subclass produces a specific NMR signal, so that analysis of the contribution of each signal to the global signal gives the concentration of particles subclasses (nanomole per litre or micromole per litre), concentration in mass of lipid subclasses (milligram per decilitre of cholesterol or triglycerides), together with mean diameters (nanometre) of very low density lipoproteins (VLDLs), low density lipoproteins (LDLs) and high density lipoproteins (HDLs). These particles sizes [Circulation 113 (2006) 113: 1556-1563] are not totally superimposable with those obtained with more classical methodologies, especially polyacrymaide gel electrophoresis of ultracentrifugally isolated lipoproteins, especially for LDLs [Clin Chem 52 (2006) 1722-1727]. Standardization of methodologies is thus required before generalising their use in clinical biology; the NMR technology especially requires complementary studies for its application to populations with extreme lipid values, such as IIa homozygous hypercholesterolemic subjects.

Dyslipidemia is a protective factor in amyotrophic lateral sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is the most serious form of degenerative motor neuron disease in adults, characterized by upper and lower motor neuron degeneration, skeletal muscle atrophy, paralysis, and death. High prevalence of malnutrition and weight loss adversely affect quality of life. Moreover, two thirds of patients develop a hypermetabolism of unknown cause, leading to increased resting energy expenditure. Inasmuch as lipids are the major source of energy for muscles, we determined the status of lipids in a population of patients with ALS and investigated whether lipid contents may have an impact on disease progression and survival. METHODS: Blood concentrations of triglycerides, cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were measured in a cohort of 369 patients with ALS and compared to a control group of 286 healthy subjects. Postmortem histologic examination was performed on liver specimens from 59 other patients with ALS and 16 patients with Parkinson disease (PD). RESULTS: The frequency of hyperlipidemia, as revealed by increased plasma levels of total cholesterol or LDL, was twofold higher in patients with ALS than in control subjects. As a result, steatosis of the liver was more pronounced in patients with ALS than in patients with PD. Correlation studies demonstrated that bearing an abnormally elevated LDL/HDL ratio significantly increased survival by more than 12 months. CONCLUSIONS: Hyperlipidemia is a significant prognostic factor for survival of patients with amyotrophic lateral sclerosis. This finding highlights the importance of nutritional intervention strategies on disease progression and claims our attention when treating these patients with lipid-lowering drugs.

Oxidative stress implication in a new phenotype of amyotrophic quadricipital syndrome with cardiac involvement due to lamin A/C mutation.

This study aimed at evaluating OS in an amyotrophic quadricipital syndrome with cardiac impairment in a family of 80 members with a mutation in lamin A/C gene. Twelve patients had cardiac involvement (5 cardiac and skeletal muscles impairment). OS was evaluated in blood samples (thiobarbituric acid-reactive substances (TBARS), carbonylated proteins (PCO)) 6 "affected patients" with phenotypic and genotypic abnormalities without heart failure and 3 "healthy carrier" patients. OS was higher in affected patients than in healthy, as shown by the higher TBARS and PCO values. Patients with cardiac and peripheral myopathy exhibited a higher OS than patients with only cardiac disease (TBARS: 1.73 +/- 0.05 vs. 1.51 +/- 0.04 mmol/l (p = 0.051), PCO: 2.73 +/- 0.34 vs. 0.90 +/- 0.10 nmol/mg protein (p = 0.47)), and with healthy carriers patients (TBARS: 1.73 +/- 0.05 vs. 1.16 +/- 0.14 mmol/l (p = 0.05), PCO: 2.73 +/- 0.34 vs. 0.90 +/- 0.20 nmol/mg protein (p = 0.47)). OS may thus contribute to the degenerative process of this laminopathy. ROS production occurs, prior to heart failure symptoms. We suggest that the extent activation may also promote the variable phenotypic expression of the disease.

[Cellular sources of reactive oxygen and nitrogen species. Roles in signal transcription pathways]. / Sources cellulaires des espèces réactives de l'oxygène et de l'azote. Implication dans la transcription et la régulation des gènes.

The history of studies regarding reactive oxygen and nitrogen species (ROS/RNS) is approximatively of 50 years. ROS were shown initially for their deleterious effects on marcormolecules such as DNA and proteins, leading to deterioration of cellular functions as an oxidative stress. On the other hand, recent studies have demonstrated that ROS/RNS act as oxidative signalling in cells, resulting in various gene expressions. This brief review focuses on the main cellular origins of ERO/ERN, such as mitochondrial respiratory chain, NAD(P)H oxidase and NO synthases, and describe the modulation by the reactive species of two major signal transduction pathways, NF-KB and AP-1 pathways.

[Conclusions, future prospects and recommendations]. / Conclusions, perspectives et recommandations.

Understanding the notion of oxidative stress implies a good knowledge of the reactivity of the different reactive oxygen species (ROS). Cell damage can be induced by an overproduction of these species and/or by a deficiency in the protective antioxidant systems. Nevertheless, ROS do not display only deleterious effects and play key-roles in cell signalisation and regulation of the expression of redox sensitive genes. Besides ROS, reactive nitrogen species (RNS) with nitric oxide (*NO) as leader element, are widely involved in biology and lead to the term "nitrosative stress" that particularly describes the damage induced by peroxynitrite, a species formed by reaction between superoxide anion and degrees NO. Nutritional strategies have been based on antioxidant-rich diets, or on supplementation with antioxidants; they could constitute adjunct therapies of interest. Given all these data, radical biochemistry must be considered as a specific discipline.

Superoxide production and NADPH oxidase expression in human rheumatoid synovial cells: regulation by interleukin-1beta and tumour necrosis factor-alpha.

OBJECTIVES: to evaluate the rheumatoid synovial cell capacity to produce superoxide anion in response to interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha), and to study the NADPH oxidase involvement in this production. MATERIAL AND METHODS: Synovial cells obtained from 7 rheumatoid arthritis (RA), 5 osteoarthritic (OA) patients, and dermal fibroblasts, were stimulated (i) with IL-1beta and TNF-alpha, or (ii) with specific oxidase activators and inhibitors, before studying superoxide production; we also studied NADPH oxidase mRNAs and protein expression, and p47-phox phosphorylation. RESULTS: Constitutive superoxide production by RA cells was increased in comparison to OA cells and dermal fibroblasts, and was stimulated by PMA and ionomycin. This production was increased after cytokine treatment of RA synovial cells. Cytokine-induced superoxide production by RA cells was inhibited by iodonium diphenyl or apocynin, suggesting the involvement of NADPH oxidase. RT-PCR and western blot analysis revealed the presence of p47-phox, gp91-phox and Nox4 in RA and OA cells, and in dermal fibroblasts. P47-phox phosphorylation was enhanced after cytokine-treatment in RA and OA cells, suggesting a PKC-mediated up-regulation of NADPH oxidase. CONCLUSIONS: NADPH oxidase is involved in the superoxide release by RA synovial cells, constitutively and after cytokine up-regulation. These cells express two different homologues (gp91-phox and Nox4).