Publications by authors named "B Schircks"

Tetrahydrobiopterin (BH(4)) is widely used as a therapeutic agent in patients with BH(4) deficiencies and mild forms of phenylketonuria (PKU) and there is an increasing need for the measurement of its plasma concentrations in patients with cardiovascular disorders. We measured BH(4) and total biopterin in dithioerythritol (DTE) pretreated plasma from four adults after oral administration of BH(4) (2, 10, and 20mg/kg body weight) using the differential iodine oxidation method. About 80% (range 64.

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We report the first example of a complete inhibition of preovulatory gonadotropin secretion resulting from administration of a luteinizing hormone releasing hormone antagonist during a spontaneous menstrual cycle. The antagonist, [( View Article and Find Full Text PDF

A patient with atypical phenylketonuria and normal liver dihydropteridine reductase and phenylalanine-4-hydroxylase activities excreted neopterin but not biopterin or dihydrobiopterin in urine. The oral administration of L-sepiapterin (1 mg/kg body weight) lowered serum-henylalanine from 17.1 to 1.

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A patient with atypical phenylketonuria (defective BH2 synthesis), detected at age 6 months because of severe muscle hypotonia and serum phenylalanine of 20 mg/100 ml, had normal activities of phenylalanine-4-hydroxylase and DHPR in liver biopsy, but only 2% activity in the phenylalanine-4-hyroxylase in vivo test using deuterated phenylalanine. After IV administration of 2.5 mg/kg chemically pure tetrahydrobiopterin bishydrochloride (BH4 .

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