Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Clin Biochem ; 37(3): 198-203, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14972641

RESUMO

OBJECTIVES: 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. DESIGN AND METHODS: Longitudinal study of 46 phenylketonuric patients (age range: 6 months-34 years). Antioxidants were measured by atomic absorption spectrophotometric, chromatographic and spectrophotometric procedures. RESULTS: 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. CONCLUSION: 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.


Assuntos
Antioxidantes/metabolismo , Fenilcetonúrias/sangue , Ubiquinona/análogos & derivados , Adolescente , Adulto , Criança , Pré-Escolar , Coenzimas , Humanos , Lactente , Modelos Lineares , Estudos Longitudinais , Selênio/sangue , Estatísticas não Paramétricas , Ubiquinona/sangue
2.
Am J Clin Nutr ; 77(1): 185-8, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12499340

RESUMO

BACKGROUND: 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. OBJECTIVE: 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. DESIGN: 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. RESULTS: 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. CONCLUSIONS: 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.


Assuntos
Antioxidantes/metabolismo , Fenilcetonúrias/sangue , Ubiquinona/sangue , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Peroxidação de Lipídeos , Masculino , Estresse Oxidativo , Fenilcetonúrias/dietoterapia , Tocoferóis/sangue
3.
Clin Biochem ; 35(1): 81-4, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11937084

RESUMO

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.


Assuntos
Linfócitos/metabolismo , Fenilcetonúrias/sangue , Ubiquinona/análogos & derivados , Ubiquinona/sangue , Adolescente , Adulto , Criança , Cromatografia Líquida de Alta Pressão , Coenzimas , Dieta , Feminino , Humanos , Masculino , Fenilalanina/sangue
4.
J Neurosci Methods ; 115(1): 63-6, 2002 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-11897364

RESUMO

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.


Assuntos
Antioxidantes/farmacocinética , Benzoquinonas/farmacocinética , Cromatografia Líquida de Alta Pressão/métodos , Eletroquímica/métodos , Ataxia de Friedreich/tratamento farmacológico , Monitorização Fisiológica/métodos , Farmacologia Clínica/métodos , Adolescente , Benzoquinonas/sangue , Criança , Cromatografia Líquida de Alta Pressão/instrumentação , Eletroquímica/instrumentação , Feminino , Humanos , Masculino , Monitorização Fisiológica/instrumentação , Farmacologia Clínica/instrumentação , Ubiquinona/análogos & derivados
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...