Browsing by Author "Pinheiro, Teresa"
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- Blood antioxidant markers and elemental levels in Azorean patients with coronary artery disease: a preliminary studyPublication . Ferin, Rita; Napoleão, Patrícia; Gomes, Carla; Castro, Ana Rita; Lopes, Paula Alexandra; Martins, Dinis; Santos, Maria Cristina; Viegas-Crespo, Ana Maria; Pinheiro, Teresa; Pavão, Maria LeonorAtherosclerosis (ATH) and related vascular diseases are the first cause of morbidity and mortality in Portugal, including the Azores’ Archipelago. The oxidation of low density lipoproteins (LDL) is considered to be an important event in the development of the disease. Accordingly, by preventing LDL oxidation, antioxidants can possibly reduce the risk or the progression of ATH. Essential trace elements as Cu, Se, Zn, and Fe are involved in endogenous antioxidant systems, mainly as cofactors of antioxidant enzymes. Other elements, like K and Ca, might play a role in atherogenesis while implicated in physiological and metabolic processes which are known to be disturbed in ATH. The aimof the present study was to evaluate some blood antioxidant markers and blood elemental levels in 20 Azorean subjects (ten men and ten women, aged 40 to 65 years) with coronary artery disease previously submitted to percutaneous revascularization (PCI). The whole blood gluthatione peroxidase (Se-GPx) and erythrocyte superoxide dismutase activities were measured, as well as serum vitamin E levels (by HPLC). The concentrations of K, Ca, Fe, Cu, Zn, and Se in plasma and blood cells were determined by PIXE. Results were analyzed by taking into account several cardiovascular risk factors, namely, gender, hypertension, dyslipidemia, and total plasma homocysteine (tHcy) concentration. Se-GPx activity and vitamin E levels were significantly lower (24 and 15%, respectively) in the PCI group than in controls. In blood cells, significantly differences in Ca (19±5 vs 24±6 μg/mL) and Zn (14±1 vs 12±2 μg/mL) levels were observed in PCI women (but not in men) compared to the respective counterparts. Also in PCI women, both serum triglyceride and plasma tHcy concentrations were above reference values and higher than in men. Results suggest a decreased antioxidant status in PCI patients. In particular, women appear to be less protected than men, as reflected in some cardiovascular risk factors.
- Blood elemental levels and antioxidant markers in humans with atherosclerotic diseasePublication . Lopes, Paula Alexandra; Napoleão, Patrícia; Pinheiro, Teresa; Santos, Maria Cristina; Rodrigues, Maria Odete; Ceia, Fátima; Vicente, Luís; Mathias, Maria da Luz; Pavão, Maria Leonor; Nève, Jean; Viegas-Crespo, Ana MariaAlthough mortality from coronary heart disease has declined recently, atherosclerosis and related vascular diseases are still the major cause of death in the western countries. Experimental studies have demosntrated that a disturbed balance between free radical formation and antioxidant defenses can play a role in the development and progression of various diseases, namely atherosclerosis. In this study trace element levels were measured in plasma and in blood cells of subjects suffering from atherosclerotic disease. Blood activities of antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GPx) and plasma total thiols were also evaluated in these patients. Significantly decreased Se and Fe were found in the blood plasma of the atherosclerotic group. A tendency for disruption in antioxidant enzyme status was observed in these patients, but plasma total thiols were unchanged. These are preliminary results and a large atherosclerotic group is required in order to clarify the observations and to contribute for the knowledge on the molecular basis of atherosclerosis.
- Blood trace element levels in patients with stabilized atherosclerosisPublication . Viegas-Crespo, Ana Maria; Napoleão, Patrícia; Lopes, Paula Alexandra; Santos, Maria Cristina; Pavão, Maria Leonor; Pinheiro, TeresaCardiovascular diseases remain the leading cause of mortality in Western populations. Dislipidemia, hypertension, diabetes, obesity and tobacco consumption are the main risk factors for atherosclerosis and its thrombotic complications. However, these factors alone cannot account for all of the deaths caused by vascular pathologies. The possible interaction of some trace element levels with atherogenic diseases is not completely clarified. On the other hand, the intra and extracellular concentrations of elements playing an important function in the electrolytic equilibrium could partially be associated with cardiovascular dysfunctions and other associated pathologies. The aim of this study was to evaluate trace elements (Fe, Ni, Cu, Zn, Se) and electrolytic –balance associated elements (Ca and K) in plasma and blood cells of patients with stabilized atherosclerosis. Significant differences between patient and control groups were observed in blood cells for the K, Fe, and Zn concentrations, while plasma K, Ca, Fe and Zn levels exhibited significant differences between groups. Results will be discussed taking into account the main function of those elements and the etiology of atherosclerosis. The relationship of results with the studied cardiovascular risk factors will be also considered.
- Systemic markers of the redox balance and Apolipoprotein E Polymorphism in Atherosclerosis: the Relevance for an Integrated StudyPublication . Lopes, Paula Alexandra; Napoleão, Patrícia; Pinheiro, Teresa; Ceia, Fátima; Steghens, Jean-Paul; Pavão, Maria Leonor; Santos, Maria Cristina; Viegas-Crespo, Ana MariaProspective studies have demonstrated that an imbalance between oxidative damage and antioxidative protection can play a role in the development and progression of atherosclerosis. Also, genotypes with the apolipoprotein E ζ4 allele have been associated with an increase risk for this pathology. Based on this knowledge, the aim of this study was to evaluate indicators of the redox balance, trace elements, and apolipoprotein E allelic profile in subjects from the Lisbon population with clinically stable atherosclerosis, at risk for atherosclerotic events, and in healthy subjects for comparison. The activities of superoxide dismutase in erythrocytes and glutathione peroxidase in whole blood, plasma total thiols, and serum ceruloplasmin were kept unchanged among the three groups. Serum α-tocopherol was increased in atherosclerotic patients. Total malondialdehyde in serum and protein carbonyls in plasma, which are indicators of lipid and protein oxidative damage, respectively, reached their highest values in risk subjects. The concentrations of potassium and calcium, in plasma and in blood cells, were slightly elevated in patients and might reflect an electrolytic imbalance. Regarding the apolipoprotein E polymorphism, atherosclerotic patients had an increased incidence of the high-risk genotypes for atherogenesis (ζ3/ζ4 and ζ4/ζ4). A multivariate model applied to the general population using most of the parameters clearly separated the three groups at study (i.e., the healthy group from the steady-state group of risk disease and from the atherosclerotic one). As shown by us, the usefulness of biochemical and complementary genetic markers is warranted for a better knowledge on atherosclerosis molecular basis.
- Trace element levels and redox markers in human atherosclerosis: relationship with Apo E PolymorphismPublication . Lopes, Paula Alexandra; Napoleão, Patrícia; Pinheiro, Teresa; Santos, Maria Cristina; Rodrigues, Maria Odete; Costa, Luciana; Ceia, Fátima; Vicente, Luís; Pavão, Maria Leonor; Nève, Jean; Viegas-Crespo, Ana MariaOxidation of LDL in the vessel wall plays an important role in the development of atherosclerotic lesions mediated by several mechanisms. Measurement of antioxidant/oxidant-related parameters and trace element levels in serum in parallel with the allelic profile of apo E may be useful in assessing the risk of atherogenesis in humans. Blood activities of antioxidant enzymes, SOD and GPx, total thiols, caeruloplasmin, α-tocopherol as well as products of oxidative damage, MDA and protein carbonyls were evaluated in patients with diagnostic atherosclerosis in parallel with matched healthy subjects. The elemental levels were assessed in plasma and blood cell fractions. The allelic frequencies of apo E were similar to those referred in the literature. Significantly decreased K, Fe and Zn levels were found in plasma of the atherosclerotic group. A tendency for a disruption in antioxidant enzyme status was observed in patients, although serum caeruloplasmin and α-tocopherol contents were unchanged. Plasma protein carbonyls levels were decreased in patients. This study could contribute for a better understanding of the relationship between genetic and redox balance markers, which is of utmost importance for the prevention of atherosclerosis.