C Colomé

University of Barcelona, Barcino, Catalonia, Spain

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Publications (25)66.75 Total impact

  • Medicina Clínica. 07/2013; 115(3):111–117.
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    ABSTRACT: To investigate the implications of the three main factors of the antioxidant system reported in relation to oxidative damage in phenylketonuric patients: selenium, ubiquinone-10 (Q10) and antioxidant enzymes over 3 years of metabolic follow-up. Longitudinal study of 46 phenylketonuric patients (age range: 6 months-34 years). Antioxidants were measured by atomic absorption spectrophotometric, chromatographic and spectrophotometric procedures. Plasma selenium concentrations in phenylketonuria (PKU) were not different from those of a healthy population. Decreased plasma Q10 concentrations were mainly related to the dietary control and the age of patients. Erythrocyte catalase activity was significantly decreased in PKU while the other enzyme activities were not different from those of a healthy population. Selenium status is not impaired in phenylketonuric patients under dietary treatment. Q10 values tend to decrease with increased patient age. Catalase activity was negatively associated with plasma phenylalanine values.
    Clinical Biochemistry 04/2004; 37(3):198-203. · 2.45 Impact Factor
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    ABSTRACT: Treatment of phenylketonuria (PKU) patients consists of a phenylalanine-restricted diet supplemented with a tyrosine-, vitamin- and oligoelement-enriched amino-acid mixture. Vitamins and oligoelements may be deficient when compliance with the supplemented special formula is poor. Plasma thiol concentrations (especially homocysteine) depend mainly on B-vitamin intake. Our aim was to evaluate the plasma thiol concentrations (homocysteine, cysteine and glutathione) and their determinants (methionine, cobalamin and folate) in PKU patients under dietary treatment compared with age-matched controls. Cross-sectional study performed in a tertiary care Hospital. PKU (42) patients under dietary treatment compared with 42 age-matched controls. Plasma total homocysteine, cysteine and glutathione were analyzed by HPLC with fluorescence detection. Plasma phenylalanine and methionine were analyzed by ion exchange chromatography. Serum folate and cobalamin were analyzed by radioimmunoassay procedures. Total homocysteine concentrations were significantly lower in the PKU patients compared with the control group (Students t-test; P<0.0001). Serum folate and cobalamin were significantly higher in the PKU group (t-Student; P<0.0001) compared with controls. A significantly negative correlation was observed between total homocysteine and folate (r=-0.378; P=0.016), and between cobalamin and phenylalanine concentrations (r=-0.367; P=0.022) in the PKU group. Plasma total homocysteine values are lower in the PKU group than in the controls, probably because of high folate values. High phenylalanine values, an indicator of poor dietary compliance, are negatively associated with cobalamin, which might be deficient in some cases.
    European Journal of Clinical Nutrition 08/2003; 57(8):964-8. · 2.76 Impact Factor
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    ABSTRACT: Low serum ubiquinone-10 concentrations have been described in phenylketonuric patients fed natural-protein-restricted diets. Such low concentrations may be related to increased free radical damage. We evaluated the relation between low serum ubiquinone-10 concentrations and other lipophilic antioxidants (tocopherol and retinol), selenium, glutathione peroxidase activity, and malondialdehyde concentrations as a marker of lipid peroxidation. This was a cross-sectional study of 58 patients with phenylketonuria (aged 2-36 y; median: 13 y) under dietary treatment, 58 age-matched control subjects, and 30 children with moderate hyperphenylalaninemia fed unrestricted diets (aged 3-17 y; median: 7.5 y). Serum ubiquinone-10 concentrations were analyzed by HPLC with electrochemical detection. Serum retinol, serum tocopherol, and plasma malondialdehyde were analyzed by HPLC with ultraviolet detection. A significant positive correlation was observed between ubiquinone-10 and tocopherol (r = 0.510, P < 0.001) in the patients with phenylketonuria. After the patients were stratified into 2 groups according to ubiquinone-10 values, significantly lower concentrations of tocopherol were observed in group 1 (low ubiquinone values) than in group 2 (normal ubiquinone values), the hyperphenylalaninemic children, and the control group. Plasma malondialdehyde concentrations were significantly higher in group 1 than in the other groups. No significant differences between groups 1 and 2 were observed in daily intakes of selenium, ascorbate, tocopherol, or retinol. Plasma lipid peroxidation seems to be increased in phenylketonuria. Low concentrations of ubiquinone-10 could be associated with either excessive tocopherol consumption or high malondialdehyde concentrations in patients with phenylketonuria.
    American Journal of Clinical Nutrition 01/2003; 77(1):185-8. · 6.50 Impact Factor
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    ABSTRACT: Antioxidant therapy has been applied to Friedreich's ataxia patients. We assessed the effect of idebenone treatment in patients with Friedreich's ataxia. Design: open-label trial. Nine Friedreich's ataxia patients (age range 11 - 19 years) were treated with idebenone (5 mg/kg/day). Patients were evaluated before the start of the therapy and throughout one year of treatment by International Cooperative Ataxia Rating Scales (ICARS) scores, neurophysiological investigations and echocardiographic measurements. Serum idebenone concentrations were measured by HPLC with electrochemical detection. The number of GAA repeats at the frataxin gene was analyzed by PCR. Serum idebenone concentrations ranged between 0.04 - 0.37 micro mol/L. Significantly positive correlation was observed between idebenone values and the percentage of difference between the ICARS scores before and 12 months after the start of the therapy (r = 0.883; p = 0.002). Significant reduction was observed comparing the ICARS scores in baseline conditions and after 3 months of treatment (p = 0.017). No differences were observed in echocardiographic measurements after the start of the therapy. Cerebellar improvement was notable in mild patients after the first 3 months of therapy. Idebenone treatment at early stages of the disease seems to reduce the progression of cerebellar manifestations. Further blind trials with a greater number of patients and higher doses are needed to fully assess the therapeutic potential of idebenone in Friedreich's ataxia.
    Neuropediatrics 09/2002; 33(4):190-3. · 1.19 Impact Factor
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    ABSTRACT: Idebenone is a quinone analog that is applied in the treatment of several neurological disorders including Friedreich ataxia and mitochondrial encephalomyopathies. Our aim was to develop an easy and sensitive analytical HPLC-procedure for the determination of idebenone in the serum of patients treated with this drug. Serum samples from nine paediatric patients diagnosed with Friedreich ataxia and receiving idebenone treatment were analyzed. Idebenone was separated from serum by reverse high-pressure liquid chromatography and analyzed using an electrochemical detection procedure. No interferences were observed during analysis of patient samples obtained prior to idebenone treatment. Calibration of idebenone concentration indicated a linear range between 500 pmol/l and 5 micromol/l and calculation of within-run and between-run coefficients of variation suggested adequate analytical quality for reliable determination. In agreement with previously reported data, during drug therapy, idebenone serum concentrations (basal conditions, range 0.1-0.49 micromol/l) were greatly elevated 90 min after an oral dose (range 0.66-3.63 micromol/l). Thus, we have developed a simple and rapid method that offers adequate analytical quality for accurate idebenone determination.
    Journal of Neuroscience Methods 04/2002; 115(1):63-6. · 2.11 Impact Factor
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    ABSTRACT: To investigate the ubiquinone-10 content in lymphocytes from phenylketonuric patients. We compared 23 patients with 25 age-matched controls. Ubiquinone-10 was analyzed by HPLC with electrochemical detection. Ubiquinone-10 concentrations were significantly lower in patients (77-270 nmol/g of protein) compared with controls (190-550) (p < 0.001). Significantly negative correlation was observed between ubiquinone-10 and phenylalanine (r = -0.441; p < 0.05). Ubiquinone-10 concentrations are decreased in lymphocytes from phenylketonuric patients. This deficiency is associated with high plasma phenylalanine concentrations.
    Clinical Biochemistry 02/2002; 35(1):81-4. · 2.45 Impact Factor
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    ABSTRACT: Objectives: To investigate the ubiquinone-10 content in lymphocytes from phenylketonuric patients.Design and methods: We compared 23 patients with 25 age-matched controls. Ubiquinone-10 was analyzed by HPLC with electrochemical detection.Results: Ubiquinone-10 concentrations were significantly lower in patients (77–270 nmol/g of protein) compared with controls (190–550) (p < 0.001). Significantly negative correlation was observed between ubiquinone-10 and phenylalanine (r = −0.441; p < 0.05).Conclusions: Ubiquinone-10 concentrations are decreased in lymphocytes from phenylketonuric patients. This deficiency is associated with high plasma phenylalanine concentrations.
    Clinical Biochemistry - CLIN BIOCHEM. 01/2002; 35(1):81-84.
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    ABSTRACT: Our aim was the detection of possible deficiencies of folate and cobalamin by the measurement of plasma total homocysteine (tHcy) in 69 human immunodeficiency virus (HIV) -infected children on antiretroviral treatment. We studied the relationship of these vitamins and methionine with tHcy values. Plasma tHcy was determined by high-performance liquid chromatography with fluorescence detection, folate and cobalamin by competitive protein-binding chemiluminescence, and methionine by ion exchange chromatography. Significant differences were observed between tHcy concentrations in the HIV-infected patients and the reference values for children of similar ages (P < 0.0001). Folate values were significantly lower in HIV-infected children compared with our reference paediatric population (P < 0.0001), but cobalamin concentrations were similar between patients and reference values. A significantly negative correlation was found between tHcy and folate (r = - 0.596; P < 0.0001), and a significantly positive correlation between folate and the methionine : tHcy ratio (r = 0.501; P < 0.0001). Plasma tHcy was significantly higher (P = 0.008), while folate values and methionine : tHcy ratios were significantly lower (P = 0.007 and P = 0.042), in patients on protease inhibitor treatment than in patients on other antiretroviral therapies. The hyperhomocysteinaemia and low methionine : tHcy ratios observed in our group of HIV-infected children are probably a consequence of the low folate values, which interfere in the remethylation of homocysteine to methionine. Patients on protease inhibitor treatment showed significantly higher plasma tHcy concentrations, and lower folate values and methionine : tHcy ratios, compared with patients on other antiretroviral therapies. Hyperhomocysteinaemia is associated with the risk of premature stroke, which may have adverse consequences in the evolution of disease.
    European Journal of Clinical Investigation 11/2001; 31(11):992-8. · 3.37 Impact Factor
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    ABSTRACT: To study the lipid profile in a group of treated phenylketonuric patients (PKU; n = 61) compared with a group of inborn error of intermediary metabolism patients (IEM; n = 22), a group of hyperphenylalaninemic children (HPA; n = 37), and a control group without dietary restriction (n = 41). Phenylalanine was analyzed by ion exchange chromatography and triglycerides, cholesterol and HDL were determined by standard procedures with the Cobas Integra analyzer. Serum total cholesterol concentrations were significantly lower in PKU patients compared with IEM patients (whose cholesterol daily intake was similar to those of PKU patients), HPA children and the control group. A negative correlation was observed between cholesterol and phenylalanine concentrations in the PKU patients. Our findings support the hypothesis of a relationship between high plasma phenylalanine levels and an inhibition of cholesterogenesis, although the low cholesterol intake of the special diets may also decrease serum cholesterol values.
    Clinical Biochemistry 08/2001; 34(5):373-6. · 2.45 Impact Factor
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    ABSTRACT: Decreased serum ubiquinone-10 concentrations is a common condition in patients with phenylketonuria (PKU) under dietary treatment. Our aim was to investigate the implication of the metabolic abnormalities of PKU (low concentrations of tyrosine and high concentrations of phenylalanine) and the effect of treatment with phenylalanine-restricted diets in decreased ubiquinone-10 concentrations in PKU patients. We studied 30 PKU patients (age range 5 months to 35 years; median age 7 years) under dietary treatment. Correlation between plasma tyrosine or phenylalanine and serum ubiquinone-10 concentrations was investigated. Daily cholesterol intake was calculated from the data obtained through a dietary questionnaire. The index of dietary control (IDC) was calculated as the average of the medians of plasma phenylalanine concentrations obtained every 6 months in the metabolic control of patients. Negative correlations were observed between serum ubiquinone and the IDC (r=-0.46; p<0.01) in PKU patients. No correlation was observed between tyrosine or daily cholesterol intake and serum ubiquinone concentrations. After adjustment for daily cholesterol intake by multiple linear regression analysis, for each 113 units of increase in IDC values serum ubiquinone decreased 0.1 micromol/L. According to our results, the main factor associated with the decreased serum ubiquinone concentrations was high plasma phenylalanine values. Although daily cholesterol intake seems to be associated with ubiquinone concentrations, it may not be relevant if we take into account the low intake of cholesterol in treated PKU patients.
    Journal of Inherited Metabolic Disease 07/2001; 24(3):359-66. · 4.07 Impact Factor
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    Diabetes Care. 01/2001; 24(5):970-971.
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    ABSTRACT: Decreased serum ubiquinone-10 concentrations is a common condition in patients with phenylketonuria (PKU) under dietary treatment. Our aim was to investigate the implication of the metabolic abnormalities of PKU (low concentrations of tyrosine and high concentrations of phenylalanine) and the effect of treatment with phenylalanine-restricted diets in decreased ubiquinone-10 concentrations in PKU patients. We studied 30 PKU patients (age range 5 months to 35 years; median age 7 years) under dietary treatment. Correlation between plasma tyrosine or phenylalanine and serum ubiquinone-10 concentrations was investigated. Daily cholesterol intake was caulculated from the data obtained through a dietary questionnaire. The index of dietary control (IDC) was calculated as the average of the medians of plasma phenylalanine concentrations obtained every 6 months in the metabolic control of patients. Negative correlations were observed between serum ubiquinone and the IDC (r=-0.46; p
    Journal of Inherited Metabolic Disease 01/2001; 24(3):359-366. · 4.07 Impact Factor
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    ABSTRACT: Congenital disorders of glycosylation (CDG) are genetic multisystemic diseases due to various defects in the biosynthesis or processing of glycoproteins. Our aim is to present our experience in the selective screening of CDG syndrome in a paediatric population (421 patients) with clinical suspicion of the disease, analysing serum carbohydrate-deficient transferrin (CDT) by radioimmunoassay and/or immunoturbidimetry. We established the normal values for our paediatric population. The abnormal results were confirmed and classified by isoelectric focusing of serum sialotransferrins, and by enzymatic and molecular studies. We found 14 patients (3.3%) with abnormal serum CDT; 11 of them were classified as CDG type Ia (CDG-Ia) and the other three showed altered isoelectrofocusing patterns but remain untyped and are under investigation. In conclusion, both CDT assays proved to be useful tools for CDG screening. Isoelectric focusing is a simple procedure but it requires specific instruments that are not always available. Since the immunoturbidimetric procedure is commonly used to monitor for recent excessive alcohol consumption in clinical laboratories and does not require special equipment, it may also be reliably used to screen for CDG in children under clinical suspicion.
    Clinical Chemistry and Laboratory Medicine 11/2000; 38(10):965-9. · 3.01 Impact Factor
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    ABSTRACT: To evaluate the results of oxygen consumption measurement in lymphocytes for the diagnosis and treatment monitoring of pediatric patients with oxidative phosphorylation diseases. Twenty-four children with an oxidative phosphorylation disease were studied. Results were compared with those of 87 healthy children. Oxygen consumption measurements in digitonine-permeabilized lymphocytes incubated with pyruvate plus malate and succinate were performed in a Clark-type oxygen electrode. A total of 58% of patients showed a decreased oxygen consumption in lymphocytes incubated with pyruvate. In 4 patients, this analysis was the unique initial biochemical test, which revealed an impaired mitochondrial energy metabolism. Significant differences were observed in lymphocytes incubated with pyruvate between patients and reference values (p<0.00005), and in lymphocytes incubated with pyruvate before and after treatment (p<0.05). This test is useful for diagnosing oxidative phosphorylation diseases in patients who did not have other biochemical alterations, although false-negative results can be found. It is not useful for treatment monitoring.
    Clinical Biochemistry 08/2000; 33(6):481-5. · 2.45 Impact Factor
  • Medicina Clínica 07/2000; 115(3):111-7. · 1.25 Impact Factor
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    ABSTRACT: The adherence of monocytes to the endothelium is an early event in atherogenesis which is modulated by low density lipoproteins (LDL). We analyzed the effect of atherogenic LDL levels (180 mg cholesterol/dl, for 24 h) with minimal oxidative modifications (thiobarbituric-acid-reactive-substances (TBARS) concentration between 1.2+/-0.1 and 2.5+/-0.3 nmol of malonaldehyde bis-diethyl acetal (MDA) per mg protein) on human umbilical vein endothelial cell (HUVEC) adhesive properties. We used native LDL (n-LDL), and LDL exposed to spontaneous oxidation without antioxidants (mox-LDL) or with 20 micromol/l of the antioxidant butylated hydroxytoluene (BHT-LDL) or 10 micromol/l U74500A (U74500A-LDL), a scavenger of free radicals. Thiobarbituric-acid-reactive-substances (TBARS) levels were significantly higher in mox-LDL (2.5+/-0.3 nmol MDA/mg protein) than in BHT-LDL (1.6+/-0.2), U74500A-LDL (1.2+/-0.1) or in n-LDL (1.3+/-0.1). mox-LDL induced the greatest adhesion of U937 cells to HUVEC (103+/-9% over controls) followed by BHT-LDL (75+/-10%), U74500A-LDL (36+/-9%) and n-LDL (35+/-3%). The lazaroid U74500A efficiently protected U74500A-LDL against oxidative damage and prevented endothelial adhesiveness associated with this LDL modification, inducing adhesion effects similar to those of n-LDL. However, U74500A could not reverse the adhesion induced by previously oxidized LDL (mox-LDL). LDL did not induce the expression of the intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) or E-selectin, but it produced a downregulation of endothelial nitric oxide synthase (NOS III) mRNA levels. Thus, adhesiveness of human endothelial cells (EC) exposed to atherogenic concentrations of LDL is closely modulated by minimal changes in LDL oxidative state, and could be related to a downregulation of NOS III.
    Atherosclerosis 05/2000; 149(2):295-302. · 3.71 Impact Factor
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    ABSTRACT: The aim of this study was to investigate a possible association among the thermolabile polymorphism, nucleotide 677 cytosine to thymidine point mutation (677 C-->T) of the methylenetetrahydrofolate reductase (MTHFR) gene, hyperhomocysteinemia, serum folate, vitamins B12 and B6, and stroke in children. Allele and genotype frequencies for the 677 C-->T polymorphism in 21 children with stroke and 28 healthy children of the same age were studied. No differences in allelic frequency were detected between the two populations. However, the prevalence of homozygous 677 C-->T was doubled in the stroke population (28.6%) compared to the healthy group (14.3%). Total plasma homocysteine (tHcy) levels were significantly increased in children aged 2 months to 15 years with stroke compared to reference values. No association was observed between the homozygous genotype (T/T) and hyperhomocysteinemia, nor between the T/T genotype and low folate levels (below the 95th percentile) in this group of patients. Vitamin concentrations in patients were not significantly different from reference values. Significant negative correlations were found between tHcy and folate and between tHcy and cobalamin, but not between tHcy and B6 concentrations. In summary, a higher prevalence of hyperhomocysteinemia and the 677 C-->T polymorphism were observed in children with stroke, but were not always associated. The systematic study of both abnormalities in children with stroke is recommended, so that hyperhomocysteinemia of any genetic origin can be corrected with vitamin supplementation. Moreover, the 677 C-->T genotype is a strong factor for predisposition to hyperhomocysteinemia and recurrent risk of stroke that might also be prevented with folate supplementation.
    Journal of Child Neurology 05/2000; 15(5):295-8. · 1.39 Impact Factor
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    ABSTRACT: The aim of the study was to observe the influence of carbamazepine and valproic acid on plasma total homocysteine and B-vitamin status and the gene-drug interaction with the 677C-->T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene. Plasma total homocysteine concentrations were determined in 136 epileptic children taking anti-epileptic drugs as monotherapy. Nutritional (folate, B12 and B6 vitamins) and genetic (MTHFR 677 C-->T) determinants of plasma homocysteine were studied in a random sample of 59 of the 136 epileptic children. Total homocysteine concentrations were significantly increased (p < 0.05) and folate and vitamin B6 levels were significantly decreased (p < 0.01) in the children taking anti-epileptic drugs compared with our reference ranges. In the carbamazepine-treated group, significantly positive correlation was found between duration of treatment and homocysteine concentration (p < 0.01). Homocysteine concentrations showed a significantly negative correlation with vitamin levels (folate: p = 0.002, and vitamin B12: p = 0.017) only in the carbamazepine treated group. In children treated with carbamazepine up to 3 years, total homocysteine concentration correlated negatively only with folate (p = 0.003), while in patients treated for more than 3 years, total homocysteine correlated negatively only with vitamin B12 values (p = 0.007). The lowering action of carbamazepine treatment on folate levels seems to be associated with hyperhomocysteinaemia, which seems to be related to the homozygous condition for the MTHFR 677C-->T mutation. Valproic acid treatment, although also associated with hyperhomocysteinaemia, only shows a lowering effect on vitamin B6 levels, which seems to be independent of the MTHFR genotype.
    European Journal of Paediatric Neurology 02/2000; 4(6):269-77. · 1.98 Impact Factor
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    ABSTRACT: Our aim was to study the presence of moderate hyperhomocysteinemia, a risk factor for premature cardiovascular disease, its modifying vitamin factors (folates, vitamins B12 and B6), and lipid risk factors in juvenile type 1 diabetes. A total of 91 patients with type 1 diabetes (46 girls and 45 boys) were studied, with ages ranging from 11 to 18 years, a duration of diabetes from 1 to 15 years, and in pubertal development (stages III, IV, V). In all patients, cholesterol, triglycerides, HDL and LDL cholesterol, lipoprotein(a), folates, cobalamin, vitamin B6, and total homocysteine were determined by specific assays. Microalbuminuria, defined as a ratio of albumin/creatinine >3 mg/mmol creatinine, was analyzed in the first morning specimen. Plasma total homocysteine (tHcy) concentrations were not different in the 91 diabetic children (median [range]) (11-15 years, 6.1 micromol/l [3.2-9.6]; 16-18 years, 7.3 micromol/l [3.9-12]) compared with the control group (11-15 years, 6.6 micromol/l [4.4-10.8]; 16-18 years, 8.1 micromol/l [4.6-11.3]). No significant differences were found in tHcy values in relation to the metabolic control of the disease as assessed by glycohemoglobin values, the duration of disease, alterations in fundus oculi, or presence of lymphocytic thyroiditis. A positive correlation was found between tHcy and plasma creatinine in type 1 diabetic patients that might be related with the increase in muscle mass. There was a negative correlation between tHcy and serum folate (P<0.001) and vitamin B12 (P<0.05), but not with vitamin B6 levels. No significant correlations were found between tHcy and the lipid parameters. Hyperhomocysteinemia was not detected in adolescents with type 1 diabetes.
    Diabetes Care 01/2000; 23(1):84-7. · 7.74 Impact Factor

Publication Stats

500 Citations
66.75 Total Impact Points

Institutions

  • 2001–2013
    • University of Barcelona
      Barcino, Catalonia, Spain
  • 1999–2003
    • Hospital Sant Joan de Déu
      • Servicio de Neurología
      Barcino, Catalonia, Spain
    • Spanish National Centre for Cardiovascular Research
      Madrid, Madrid, Spain
  • 2000
    • IR-Sant Pau - Sant Pau Institute of Biomedical Research
      Barcino, Catalonia, Spain
  • 1998
    • Autonomous University of Barcelona
      Cerdanyola del Vallès, Catalonia, Spain