Potential role of the "NADPH oxidases" (NOX/DUOX) family in cystic fibrosis.

Cystic fibrosis (CF), is the most common life-shortening autosomal recessive disorder in Caucasians. It is caused by mutations in a single gene on the long arm of chromosome 7 that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) protein. CF is characterized by abnormal Na+ and Cl- ion transport in several tissues, including the lungs, pancreas, gastrointestinal tract, liver, sweat glands, and male reproductive system. Progressive pulmonary disease is the dominant clinical feature of CF and accounts for morbidity and mortality. The inflammation characterized by an overabundance of activated neutrophils and macrophages on the respiratory epithelial surface is associated to a high production of reactive oxygen species (ROS) which contribute to the pathogenesis of cystic fibrosis. ROS could have different origins but the role of the NADPH oxidase system is essential. The "NADPH oxidases" (NOX/DUOX) family is an enzymatic complex formed by cytosolic and membrane subunits. Until now several homologues of the phagocytic NADPH oxidase have been identified in different tissues and it has been shown that the lungs preferentially expressed DUOX1-2. Thus, DUOX1-2 could be implicated in the anti-infectious defense system. The role of DUOX enzymes as a source of ROS in cystic fibrosis is examined as they could contribute to a better understanding of molecular mechanisms in CF. Moreover they could be a potential target for a new therapeutic approach.

[Biochemical exploration of energetic metabolism and oxidative stress in low grade gliomas: central and peripheral tumor tissue analysis]. / Exploration biochimique du métabolisme énergétique et du stress oxydant des gliomes de bas grade: analyse du tissu tumoral central et périphérique.

Gliomas represent 50% of primary brain tumors, and their prognosis remains poor despite the advances in diagnosis and therapeutic strategies. Low grade gliomas (LGG) are infiltrative tumors and they constantly undergo malignant transformation. Metabolic exploration of human gliomas in vivo, in animals and by using cell culture models showed important differences between tumor tissues and normal brain tissues, which can provide new markers for diagnosis, prognosis and therapeutic targets. In this study, energetic and oxidant metabolisms were explored in biopsy extracts of LGG obtained from the centre and the periphery of tumors. Metabolic pattern of these tumors was explored and the differences between the centre and the periphery pointed. Our study showed a metabolic heterogeneity between tumors, with hypermetabolic and hypometabolic profiles. Lactate to pyruvate ratio was>1, suggesting that the energy metabolism in LGG is glycolytic in nature, particularly in the centre of the tumors. Peripheral samples of tumors showed increased glucose consumption and cytochrome c oxidase activity. Lipid peroxidation and catalase activity were also increased in the periphery compared to the centre of tumors. A relationship between the main antioxidant and energy metabolism enzymes activities was observed, suggesting that periphery of tumors is more active metabolically and more resistant to free radical injury.

[Cellular energetic metabolism of cerebral tissue: metabolic characteristics of glial tumours]. / Métabolisme énergétique cellulaire du tissu cérébral: spécificités métaboliques des tumeurs gliales.

This review reports recent observations concerning specificities of the cellular energy metabolism in cerebral tissues that highlight on characteristics of that of glial tumours, such as the association of metabolic alterations aggressiveness of these tumours. Compared to normal cerebral tissue, glial tissue exhibits both a relative independence towards oxygen and substrate furnitures and thus vascularization, as well as the metabolic co-operation of neurons and glial cells within the tumour. Occurrence of a Warburg effect could explain such metabolic autonomy that might be associated to genetic changes observed in gliomas. Characteristics of the glycolytic metabolism within glioma tissue therefore may be novel land therapeutic approaches for the treatment of these tumours.

Elevated circulating levels of matrix metalloproteinase-9 in type 1 diabetic patients with and without retinopathy.

OBJECTIVE: Tissue expression pattern of matrix metalloproteinases (MMPs) and their inhibitors TIMPs indicate that microvascular complications of diabetes mellitus are associated with extracellular matrix remodelling. We investigated whether circulating levels of MMP-9 and TIMP-1 are altered in diabetic retinopathy and whether they might serve as biological markers of ocular complications in type 1 diabetes. RESEARCH DESIGN AND METHODS: We recruited 47 type 1 diabetic patients free of vascular complications (n=40) or with retinopathy (n=14). Patients with macroangiopathy, neuropathy and nephropathy were excluded. A group of nondiabetic control subjects (n=35) was also constituted for comparative purposes. Peripheral blood levels of MMP-9 and TIMP-1 were determined using immunoenzymatic assays. RESULTS: Type 1 diabetic subjects exhibited significantly higher circulating levels of both MMP-9 and MMP-9/TIMP-1 ratio, as well as a tendency to increased serum TIMP-1 levels relative to nondiabetic controls (p<0.001). Diabetic patients with retinopathy also displayed elevated systemic values of MMP-9 and MMP-9/TIMP-1 ratio when compared to patients without retinopathy (p<0.05). Logistic regression analysis identified diabetes duration firstly (P<0.01), and MMP-9 serum levels secondly (P<0.01) as significant and independent variables associated with the existence of retinopathy. CONCLUSIONS: Our data suggest that peripheral blood MMP-9 levels might serve as surrogate biomarkers of retinopathy in type 1 diabetic patients free of other vascular complications.

[Sodium/iodide symporter: physiopathological aspects and therapeutic perspectives]. / Le symporteur sodium/iodure: données récentes et perspectives thérapeutiques.

The existence of the natriuric/iodide symporter (NIS) represents a new view to understand the thyroid metabolism of iodide. Due to its cellular localisation on basolateral membrane, this transporter exerts an essential role in the biological functions of the thyroid, especially the capacity to accumulate iodide into the thyrocytes. Clinical perspectives of NIS activity modulation would ameliorate the diagnosis and the treatment of thyroid diseases by using radioisotopes transported by the NIS (131 iodide, 99m technetium, 188 rhenium). The study of the regulation pathways modulating the expression and the activity of the symporter NIS, would allow to understand pathogeny of benign or malignant diseases of the thyroid gland. The relative facility of the therapy management by 131 iodide and its good efficiency associated to the recent advance of NIS function also give an interesting perspective to the gene therapy treatment of the nonthyroid cancers despite existent methodological problems.

[Analytical aspects of the semiquantitative determination of urinary iodine using ferroin: value of rapid screening for iodine deficiency or excess]. / Aspects méthodologiques de la détermination semi-quantitative de l'iodurie par la ferroïne: intérêt dans le dépistage rapide de carence ou surcharge en iode.

Iodine is an essential element for thyroid hormone synthesis. Iodine disorders induced biological and/to clinical expression of thyroid dysfunction. Inappropriate iodine intake (by default or by excess) is worrying in terms of public health in France regarding the iodine deficiency and the frequency of iatrogen iodine overloads. Urinary iodine determination which generally implicates the use of a cerimetric method, is an useful tool to evaluate iodine intakes. In this study, we described the analytical aspects of a semiquantitative method of urinary iodine using a redox indicator, ferroin. This method allows the screening of iodine excess or deficiency in a short time (< 3 hours) with a good specificity and sensitivity. Since this assay does not require specific apparatus, it could be easily developed in clinical chemistry laboratories for the detection of inappropriate iodine intakes, and could be useful for prevention programs of iodine deficiency.

[What perception have smokers of nicotine and tar yields of cigarettes?]. / Quelle perception ont les fumeurs des rendements standards en nicotine et goudrons des cigarettes?

INTRODUCTION: Advertising information on cigarette package participate to the reduction of health risks from smoking. Impact on smokers has been poorly studied. This study intended to determine the smoker perception of nicotine and tar yields of cigarettes. METHODS: Consulting in an outpatient smoking cessation clinic, 171 smokers answered freely and spontaneously to a questionnaire evaluating their perception of nicotine and tar yields, cigarette consumption (number and brand), nicotine dependence. Simultaneously, biological tobacco markers were measured. RESULTS: The number of cigarettes, nicotine dependence and specific tobacco markers were not significantly different according to the cigarette type: "full savour", "light" or "ultra light". Women smoked less than men and 54% preferred "light" cigarettes versus 37% of men. These smokers were entering a tobacco cessation program, it was assumed they had lead a prior reflection about their smoking habits. Only 8% of them gave the correct values of nicotine and tar yields and 14% gave approximate values. Tar levels were highly underestimated. CONCLUSIONS: This study shows that smokers have actually no interest for nicotine and tar yields. As the new decree which modifies manufacture's obligation concerning the legal mentions, is applicable in January 2004 in France; our conclusion may change in the future.

A fluorescence microplate assay using yopro-1 to measure apoptosis: application to HL60 cells subjected to oxidative stress.

A new one-step labeling procedure using the membrane permeant fluorescent probe yopro-1 in association with fluorescence microtitration for the rapid determination of apoptosis is reported. Programmed cell death was induced by the pro-apoptotic agents etoposide and staurosporine, and measured in nonadherent HL60 cells and adherent phorbol 12-myristate 13-acetate (PMA)-treated HL60 cells. Cell viability was controlled by trypan blue exclusion and calcein-AM staining. To confirm results of fluorescence microplate assay, apoptosis was measured by flow cytometry analysis using the same fluorescent probe, and results showed corresponding data between both procedures. Development of apoptosis was confirmed by the presence of PARP (poly(ADP-ribose) polymerase cleavage and nuclear DAPI (4,6-diamidino-2-phenylindole) staining, two well-known methods used to investigate apoptosis. The fluorescence microplate assay was also applied to measure apoptosis in cells exposed to an oxidative stress induced by tert-butylhydroperoxide (t-BHP), and results confirmed the potential of the fluorescence microplate assay in measuring events of apoptosis, especially in adherent, cultured, living cells.

[Matrix metalloproteinases and atherosclerosis. Therapeutic aspects]. / Métalloprotéases matricielles et athérosclérose. Perspectives thérapeutiques.

Matrix metalloproteinases (MMPs) play a key role in the physiology of connective tissue development, morphogenesis and wound healing, but their unregulated activity has been implicated in numerous disease processes including arthritis, tumor cell metastasis and atherosclerosis. MMP family consists of at least 20 members; MMPs are produced by the different cell types (vascular smooth muscle cells, monocytes, endothelial cells) involved in the atheromatous plaque formation and participate to extracellular matrix remodelling and cell infiltration or migration. Since excessive tissue remodelling and increased matrix metalloproteinase activity have been demonstrated during atherosclerotic lesion progression (including plaque disruption), MMPs represent a potential target for therapeutic intervention to modify vascular pathology, by restoring the MMP/TIMP physiological equilibrium. This review highlights the structures of MMPs and their physiological inhibitors, the Tissue Inhibitors of MMPs (TIMPs), and describes the current developments in pharmacological MMP inhibition.

[Value of the protein profile in the diagnosis of infectious endocarditis when hemolysis is present]. / Apport du profil protéique pour le diagnostic d'endocardite infectieuse quand il révèle une hémolyse.

PURPOSE: Haptoglobin (H) and orosomucoid (O) are acute phase proteins that increase in a parallel manner. When hemolysis and inflammation are both present, study of the O-H couple on the protein profile may reveal an unknown hemolysis. METHODS: To determine if hemolysis is more frequent during infectious endocarditis than during septicemia without valvulopathy or during valvulopathy without septicemia. Study of three groups of patients: 26 patients with infectious endocarditis, 13 patients with septicemia and 36 patients with valvulopathy without septicemia. Studied parameters were the O-H couple, hemoglobin and rate of O. RESULTS: Hemolysis is clear in patients with endocarditis. The difference O-H is significantly more important during endocarditis than during septicemia without valvulopathy (P < 0.001) and during valvulopathy without sepsis (P < 0.001). CONCLUSION: Study of the O-H couple may be useful for the diagnosis of endocarditis showing a difficult-to-diagnose hemolysis.

[New non-lipidic biological markers of atherosclerosis]. / Nouveaux marqueurs biologiques non lipidiques de l'athérosclérose.

Recent research indicates that both inflammation and infection of coronary arteries are intimately involved in the development and the progression of atherosclerosis. Pathophysiological mechanisms of formation of the atheromatous plaque are complex, resulting from the activation of endothelial cells, monocytes and foam cells, and smooth muscle cells. Numerous molecules are involved in these mechanisms, including adhesion molecules, pro-inflammatory and anti-inflammatory cytokines, chemokines, extracellular matrix remodelling enzymes, coagulation and fibrinolysis factors and infectious agents. Studies have suggested a potential role for these molecules as markers of the development of coronary artery disease and of adverse cardiac-related outcomes in patients with known coronary artery syndromes, in combination with independent risk factors such as homocysteine. This review presents recent data that could contribute to use of these markers for the diagnosis and the evolution of atherosclerosis. in clinical practice.

Homocysteine and lipid lowering agents. A comparison between atorvastatin and fenofibrate in patients with mixed hyperlipidemia.

BACKGROUND: Hyperhomocysteinemia is a risk factor for cardiovascular disease. Elevation in homocysteine levels has recently been demonstrated during lipid lowering treatment with fibrates. We compared the effect of a statin and a fibrate (atorvastatin and fenofibrate) on plasma levels of homocysteine and other thiol compounds in hyperlipidemic patients. METHOD AND RESULTS: The study was of open randomized, parallel design with a preliminary screening phase, and a 6 week placebo period. After the placebo period, patients were allocated randomly to atorvastatin or fenofibrate for a 6 month period. Plasma thiols were assayed by high pressure liquid chromatography with fluorescence detection. There were 29 patients in the fenofibrate group and 24 in the atorvastatin group. Fenofibrate induced a significant increase in both homocysteine and cysteine plasma levels (+35.8 and +18%, respectively, P<0.0001); by contrast, cysteinylglycine remained stable. There were no significant changes in any thiol compounds in the atorvastatin group. Both treatments induced a significant decrease in uric acid, although fenofibrate was noticeably more effective than atorvastatin (-22.8 and -6.4%, respectively). Fenofibrate induced a non-significant increase in creatinine (12%) while atorvastatin reduced it (4.7%, NS). CONCLUSION: Our study confirms that the induction of elevations in plasma homocysteine and cysteine levels are a distinct feature of the pleiotropic effects of fibrates. Further studies are needed not only to investigate the potential deleterious effects of this modification, but also to define the specific mechanism which underlies such fibrate-mediated action.

A new approach for rapid detection and typing of serum monoclonal components.

When used independently, none of the routine methods to explore serum monoclonal components (MC), including: serum protein electrophoresis (SPE), immunoelectrophoresis (IEP), kappa to lambda ratio (KLR) and immunofixation (IFE), provides a comprehensive quantitative and qualitative identification of the MC. In the past few years the concept of 'protein profile', based on immunonephelometric quantifications of serum proteins, has become widely used. It consists of a qualitative and quantitative graphic representation of numerous serum proteins including immunoglobulins. Aim of study was to develop a multidimensional model based exclusively on protein profiles labeled the protein profile prediction method (PPPM) to improve routine MC detection and typing. Serum samples from 127 hospitalized patients and 99 healthy blood donors were submitted to all of the following: SPE, IFE, KLR and a protein profile (which included IgM, IgA, IgG, kappa and lambda chain detections and quantification). The presence of a MC using IFE was chosen as the gold standard. Healthy donors and patients were randomly divided into two groups defined as testing and validation groups. A logistic model was designed based on the protein profiles of the testing group leading to the determination of a threshold value (called Z(r)) for MC detection. It was then tested to detect MC in the validation group. Using IFE, 73 MC were found in the 127 hospitalized patients. Using the threshold value for MC detection of Z(r)=1.86, the PPPM showed greater sensitivity (94.6%) in detecting a MC compared to either SPE (64.8%) or KLR (89.2%). This result was obtained without diminished specificity (80.8%). The association of SPE or KLR to PPPM did not significantly increase the sensitivity of the PPPM. In the validation group, for samples which had a high predictive probability of a MC using PPPM, the correct MC typing was identified in up to 77% of sera using PPPM only. These results may be interesting in helping to determine when supplementary IFE analysis is required to qualitatively analyze a MC. PPPM allows MC detection with great sensitivity. The immune protein profile dramatically increases the sensitivity of either SPE and/or KLR in detecting MC and may also allow heavy and light chain typing.

[Hyperhomocysteinemia and arterial or venous thrombosis. Retrospective study of 75 cases]. / Hyperhomocystéinémie et thromboses artérielles ou veineuses. Etude rétrospective de 75 observations.

OBJECTIVE: Previous studies suggest that hyperhomocysteinemia may be a risk factor for arterial and venous thrombosis. We retrospectively analyzed data from 75 patients with thrombosis. PATIENTS AND METHODS: Thirty-four patients had arterial thrombosis, 22 venous thrombosis and 19 venous and arterial thrombosis. Of the 75 patients (49 men and 26 women, mean age 49 +/- 15 years) about two-thirds had recurrent episodes of thrombosis. RESULTS: Hyperhomocysteinemia was defined as serum homocysteine level above 14.1 mumol/l (mean + 2.7 SD in healthy subjects) and was found in 67 patients (89%, CI95% = 80-95). Mean total homocysteine concentration was 21.6 +/- 13.6 mumol/l for the 75 patients. About half of the patients were smokers, 35% had hypertension and 25% high serum cholesterol. There was no significant relationship between serum homocysteine level and smoking status, hypertension or serum cholesterol level. Ten patients (13%, CI95% = 7-23) had low serum cobalamin (< 150 pmol/l). Serum folates were < or = 10 nmol in 41% of the patients in the arterial thrombosis group (CI95% = 25-59), in 27% in the venous thrombosis group (CI95% = 11-50), and in 31% in the arterial and venous thrombosis group (CI95% = 13-57). Thirteen patients received vitamin B supplementation. Hyperhomocysteinemia decreased in 12/13 patients (CI95% = 64-100) and returned to normal values in 9/13 patients (69%, CI95% = 38-91). CONCLUSION: Our data show that hyperhomocysteinemia is frequently found in arterial and venous thrombosis. Further studies are needed to determine the clinical impact of homocysteine lowering therapy.

Cysteine is a cardiovascular risk factor in hyperlipidemic patients.

Several studies have reported that moderate hyperhomocysteinemia is related to an increased risk for atherosclerosis, but few data are available with regard to any other thiol compound having a potential vascular toxicity. Therefore, we measured both total cysteine and homocysteine plasma levels in patients with hyperlipidemia (242 males and 147 females, 41-65 years old). Homocysteine was higher in males than in females, 13.2+/-4.1 versus 11.1+/-3.4 micromol/l (P<0.0001). The mean cysteine level was 243.3+/-45.7 micromol/l in the whole study population. The subjects were split in two groups, symptomatic patients with cardiovascular disease (n = 106) and asymptomatic subjects (n = 283). Blood pressure, smoking status, total cholesterol, LDL-cholesterol and triglycerides did not statistically differ between groups, but the mean HDL-cholesterol level was lower in symptomatic patients (1.24+/-0.38 versus 1.42+/-0.41, P<0.0001). Cysteine levels were higher in patients with cardiovascular disease than in asymptomatic patients, respectively 254.7+/-47.7 versus 239.1+/-44.3 micromol/l (P = 0.003). A similar result was found for homocysteine, respectively 13.1+/-4.3 versus 12.2+/-3.9 micromol/l (P = 0.05). To analyse whether cysteine levels were related to atherosclerosis independently of age, adjusted levels were compared between asymptomatic patients with normal carotid arteries (n = 176), carotid atherosclerosis (n = 107) and symptomatic patients (n = 106). Age adjusted cysteine levels differed significantly between groups (P = 0.027) while the P-value was of borderline significance for homocysteine (P = 0.09). Odds ratios for having symptomatic cardiovascular disease were 1.81 (95% CI, 1.02-3.21) and 2.05 (95% CI, 1.16-3.60) for the mid and highest tertiles of cysteine using the lowest as the reference. After adjustment in a multivariate model including age, sex, and creatinine, the odds ratio for disease remained significant between the highest tertile versus the lowest (OR = 1.89). Adjusted odds ratios were found to be weaker when homocysteine tertiles were compared. Our data suggest that plasma total cysteine is a risk factor for atherosclerosis in hyperlipidemic patients.

Cardiac troponin I cutoff values to predict postoperative cardiac complications after circulatory arrest and profound hypothermia.

OBJECTIVE: Cardiac failure and myocardial infarction are complications of thoracic aorta, thoracoabdominal aorta, or aortic arch surgery, especially when surgery is performed using profound hypothermia and circulatory arrest (PHCA). Moreover, the diagnosis of non-Q-wave postoperative myocardial infarction (PMI) is challenging because there is no gold standard. The aims of this study were to determine values for cardiac troponin I (cTnl) in patients undergoing aortic arch or thoracoabdominal aortic surgery with PHCA who were free of cardiac complications in the postoperative period, and to test the validity of cutoff values of cTnl to predict postoperative cardiac complications in such patients. DESIGN: Prospective, nonrandomized study. SETTING: Single university hospital; Departments of Anesthesiology, Biochemistry and Vascular Surgery. PARTICIPANTS: Fifty-two consecutive patients were studied over a 2-year period. None was excluded, even patients who underwent emergency surgery. INTERVENTIONS: Patients undergoing aortic arch or thoracoabdominal aortic surgery with PHCA were studied. Thirty patients undergoing coronary artery bypass grafting (CABG) in the same period constituted a control group. MEASUREMENTS AND MAIN RESULTS: The cTnl concentrations were determined using an immunoenzymofluorometric assay on a Stratus analyzer (Dade, Massy, France) on blood samples obtained at recovery and on day 1 (D1) and D2. Seventeen patients developed a cardiac complication, which was lethal in 10 patients. In patients without cardiac complication, the peak level for cTnl was observed on D1. Cutoff values of cTnl were identical in both the CABG control group (11 .6 microg/mL) and the sternotomy group (12.2 microg/mL), but were significantly greater (20.5 microg/mL) in patients with a thoracotomy approach. Sensitivity and specificity of these cutoff values were high in both groups (control group, sensitivity = 100%, specificity = 100%; sternotomy group, sensitivity = 78%, specificity = 100%; thoracotomy group, sensitivity = 100%, specificity = 94%). CONCLUSION: In patients who underwent surgery using PHCA for aortic arch or descending aorta repair, myocardial damage related to cardiac arrest, vents or fibrillation explains the increased cutoff value (12.2 microg/mL). This value is similar to patients undergoing CABG surgery through a sternotomy approach with cardioplegia administration. In contrast, and probably related to the absence of cardioplegia, patients undergoing surgery through a left thoracotomy approach had a greater cutoff value (20.5 microg/mL). Values of cTnl greater than these respective cutoff values were closely related to cardiac complications during the postoperative period.