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Biosynthesis and metabolism of pterins in peripheral blood mononuclear cells and leukemia lines of man and mouse.
Neopterin is an unspecific marker for the activation of the cellular immune system and is explained by the different regulation of the rate-limiting steps of tetrahydrobiopterin biosynthesis in man and in mouse. Expand
Differential diagnosis of tetrahydrobiopterin deficiency
Since subvariants of patients with BH4 deficiency exist, homovanillic acid, 5-hydroxyindole acetic acid, pterins, phenylalanine, and tyrosine in cerebrospinal fluid should be measured for diagnosis and the control of therapy. Expand
GTP cyclohydrolase I deficiency, a new enzyme defect causing hyperphenylalaninemia with neopterin, biopterin, dopamine, and serotonin deficiencies and muscular hypotonia
This is the first case of a new variant of hyperphenylalaninemia in which the formation of dihydroneopterin triphosphate and its pterin metabolites in liver is markedly diminished, and it is concluded that the molybdenum cofactor of these enzymes may not be derived from dihydroneship in man. Expand
Serotonin and dopamine synthesis in phenylketonuria.
In two patients with dihydrobiopterin synthetase deficiency, the dopamine, and even more pronounced the serotonin, excretions are considerably reduced and the dopamine excretion was reduced to about 50% and the serotonin excretion to only 10% compared to controls. Expand
[5] Thin-layer chromatography (TLC) of amino acids
Publisher Summary This chapter discusses the thin-layer chromatography (TLC) of amino acids. TLC is an experimentally simple and inexpensive method that permits very rapid and efficient qualitativeExpand
GTP-cyclohydrolases: a review.
The occurrence, properties and functions of GTP-cyclohydrolases in mammalian and non-mammalian systems is reviewed and a variant form of tetrahydrobiopterin-deficient hyperphenylalaninaemia is described. Expand
Interferon-gamma enhances biosynthesis of pterins in peripheral blood mononuclear cells by induction of GTP-cyclohydrolase I activity.
It appears that IFN-gamma selectively stimulates the early steps of pterin biosynthesis in macrophages, thereby leading to accumulation and excretion of dihydroneopterin and neopterin. Expand
[6] Thin-layer chromatography of amino acids and derivatives.
The chapter discusses the special requirements for TLC and the importance of careful standardization of the technique, including the following: quality of layer material, layer thickness and homogeneity, layer activation and relative humidity, amount of sample applied, narrow starting point or line, effective drying of the applied sample, quality of solvent (aging), chamber saturation, chamber volume and geometry, temperature. Expand
Atypical phenylketonuria due to tetrahydrobiopterin deficiency. Diagnosis and treatment with tetrahydrobiopterin, dihydrobiopterin and sepiapterin.
Investigating the effect of administration of several pterins on serum phenylalanine concentration (Phe) and urinary pterin excretion was investigated in two patients with atypical phenylketonuria (PKU) and demonstrates that BH4, BH2, L -sepiapterin and Neh4, in admixture with ascorbic acid, can be absorbed easily upon oral administration. Expand