Mostrando 1-12 de 20 artigos, teses e dissertações.
1. Exercício aeróbico regular restaura os níveis de catecolaminas em glândulas supra-renais de ratos com hiperfenilalaninemia
Fenilcetonúria é caracterizada pela deficiência da enzima fenilalanina hidroxilase, causando acúmulo de fenilalanina, o que acaba por provocar distúrbios no sistema nervoso central. Diagnóstico precoce e subordinação à dieta hipoprotéica evita as alterações decorrentes. Porém, não aderir estritamente a essa dieta leva à diminuição da concent
Publicado em: 2011
2. Hiperfenilalaninemia por deficiência de fenilalanina hidroxilase : avaliação da responsividade ao BH4 em pacientes acompanhados no Serviço de Genética Médica do HCPA e que apresentam controle metabólico adequado
Introdução: Estudos recentes, utilizando vários protocolos, têm demonstrado que pacientes com Hiperfenilalaninemia por deficiência de fenilalanina hidroxilase (HPA-PAH) podem apresentar redução das concentrações plasmáticas de fenilalanina (Phe) mediante a administração de tetrahidrobiopterina (BH4). Objetivo: Determinar, em uma amostra de pacien
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
3. Pahhph-5: a mouse mutant deficient in phenylalanine hydroxylase.
Mutant mice exhibiting heritable hyperphenylalaninemia have been isolated after ethylnitrosourea mutagenesis of the germ line. We describe one mutant pedigree in which phenylalanine hydroxylase activity is severely deficient in homozygotes and reduced in heterozygotes while other biochemical components of phenylalanine catabolism are normal. In homozygotes,
4. Mutations in the Sepiapterin Reductase Gene Cause a Novel Tetrahydrobiopterin-Dependent Monoamine-Neurotransmitter Deficiency without Hyperphenylalaninemia
Classic tetrahydrobiopterin (BH4) deficiencies are characterized by hyperphenylalaninemia and deficiency of monoamine neurotransmitters. In this article, we report two patients with progressive psychomotor retardation, dystonia, severe dopamine and serotonin deficiencies (low levels of 5-hydroxyindoleacetic and homovanillic acids), and abnormal pterin patter
The American Society of Human Genetics.
5. Hph-1: A Mouse Mutant with Hereditary Hyperphenylalaninemia Induced by Ethylnitrosourea Mutagenesis
Ethylnitrosourea mutagenesis of spermatogonial stem cells and a three-generation breeding scheme were used to screen for recessive mutations that cause defects in phenylalanine metabolism leading to elevated serum levels of this amino acid. This paper describes the isolation of such a mutation, hph-1, causing a heritable hyperphenylalaninemia in the neonate
6. Medical genetics: advances in brief: Maternal mild hyperphenylalaninemia: results of treated and untreated pregnancies in two sisters
7. Characterization of the wild-type form of 4a-carbinolamine dehydratase and two naturally occurring mutants associated with hyperphenylalaninemia.
The characterization of 4a-carbinolamine dehydratase with the enzymatically synthesized natural substrate revealed non-Michaelis-Menten kinetics. A Hill coefficient of 1.8 indicates that the dehydratase exists as a multisubunit enzyme that shows cooperativity. A mild form of hyperphenylalaninemia with high 7-biopterin levels has been linked to mutations in t
8. Conversion of 6-substituted tetrahydropterins to 7-isomers via phenylalanine hydroxylase-generated intermediates.
A new variant form of hyperphenylalaninemia has recently been discovered in which the patients characteristically excrete 7-biopterin in their urines in addition to the natural 6-biopterin (Curtius, H. Ch., Kuster, T., Matasovic, A., Blau, N. & Dhondt, J.-L. (1988) Biochem. Biophys. Res. Commun. 153, 715-721). This isomer had not been found previously in hum
9. Biopterin synthesis defect. Treatment with L-dopa and 5-hydroxytryptophan compared with therapy with a tetrahydropterin.
We have identified a generalized deficiency of monoamine neurotransmitters in a patient with a defect in biopterin synthesis. Neurotransmitter precursors (L-3,4-dihydroxyphenylalanine [L-dopa]; 5-hydroxytryptophan [5-HTP] and a tetrahydropterin [6-methyltetrahydropterin (6MPH4)] were investigated for their ability to normalize monoamine neurotransmitter meta
10. PAH Mutation Analysis Consortium Database: a database for disease-producing and other allelic variation at the human PAH locus.
The PAH Mutation Analysis Consortium (81 investigators, 26 countries) is engaged in mutation detection at the human PAH locus. Ascertainment of probands occurs largely through newborn screening for hyperphenylalaninemia. A relational database records allelic variation (disease-producing and polymorphic) at the locus. Information is distributed by Newsletter,
11. Human dihydropteridine reductase: characterisation of a cDNA clone and its use in analysis of patients with dihydropteridine reductase deficiency.
Deficiency of human dihydropteridine reductase (hDHPR) causes malignant hyperphenylalaninemia. We report the isolation of a cDNA clone for hDHPR that spans the complete coding region, and present the nucleotide sequence and the predicted amino acid sequence. The hDHPR protein does not share extensive homology with the enzymatically related protein human dihy
12. Mouse Models of Human Phenylketonuria
Phenylketonuria (PKU) results from a deficiency in phenylalanine hydroxylase, the enzyme catalyzing the conversion of phenylalanine (PHE) to tyrosine. Although this inborn error of metabolism was among the first in humans to be understood biochemically and genetically, little is known of the mechanism(s) involved in the pathology of PKU. We have combined mou