Combined tetrahydrobiopterin-phenylalanine loading test in the detection of partially defective biopterin synthesis

1984 ◽  
Vol 142 (2) ◽  
pp. 126-129 ◽  
Author(s):  
F. G�ttler ◽  
H. Lou ◽  
C. Lykkelund ◽  
A. Niederwieser
Keyword(s):  
Loading Test ◽  
Phenylalanine Loading ◽  
Biopterin Synthesis

Discrimination of phenylketonurics from persistent hyperphenylalaninemia patients using a simple phenylalanine loading test

1985 ◽  
Vol 153 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Miriam G. Blitzer ◽  
Joan E. Bailey-Wilson ◽  
Emmanuel Shapira
Keyword(s):  
Loading Test ◽  
Phenylalanine Loading

Oral phenylalanine loading test for the diagnosis of dominant guanosine triphosphate cyclohydrolase 1 deficiency

2006 ◽  
Vol 39 (9) ◽  
pp. 893-897 ◽  
Author(s):  
Eduardo López-Laso ◽  
Aida Ormazabal ◽  
Rafael Camino ◽  
Francisco J. Gascón ◽  
Juan J. Ochoa ◽  
...  
Keyword(s):  
Guanosine Triphosphate ◽  
Loading Test ◽  
Phenylalanine Loading

scholarly journals Urinary Neopterin and Phenylalanine Loading Test as Tools for the Biochemical Diagnosis of Segawa Disease

2012 ◽  
pp. 67-75 ◽  
Author(s):  
Vincenzo Leuzzi ◽  
Claudia Carducci ◽  
Flavia Chiarotti ◽  
Daniela D’Agnano ◽  
Maria Teresa Giannini ◽  
...  
Keyword(s):  
Loading Test ◽  
Biochemical Diagnosis ◽  
Phenylalanine Loading ◽  
Urinary Neopterin

Pitfalls in phenylalanine loading test in the diagnosis of dopa-responsive dystonia

2013 ◽  
Vol 108 (3) ◽  
pp. 195-197 ◽  
Author(s):  
Thomas Opladen ◽  
Georg F. Hoffmann ◽  
Andrea A. Kühn ◽  
Nenad Blau
Keyword(s):  
Loading Test ◽  
Phenylalanine Loading

scholarly journals A novel missense mutation pattern of the GCH1 gene in dopa-responsive dystonia

2007 ◽  
Vol 65 (4b) ◽  
pp. 1224-1227 ◽  
Author(s):  
Rosana H. Scola ◽  
Carla Carducci ◽  
Vanise G. Amaral ◽  
Paulo J. Lorenzoni ◽  
Helio A.G. Teive ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Molecular Genetic ◽  
Loading Test ◽  
Hydroxylase Deficiency ◽  
Inherited Metabolic Disorder ◽  
Generalized Dystonia ◽  
Phenylalanine Loading ◽  
Mutation Pattern ◽  
Gch1 Gene ◽  
Tyrosine Hydroxylase Deficiency

Dopa-responsive dystonia (DRD) is an inherited metabolic disorder now classified as DYT5 with two different biochemical defects: autosomal dominant GTP cyclohydrolase 1 (GCH1) deficiency or autosomal recessive tyrosine hydroxylase deficiency. We report the case of a 10-years-old girl with progressive generalized dystonia and gait disorder who presented dramatic response to levodopa. The phenylalanine to tyrosine ratio was significantly higher after phenylalanine loading test. This condition had two different heterozygous mutations in the GCH1 gene: the previously reported P23L mutation and a new Q182E mutation. The characteristics of the DRD and the molecular genetic findings are discussed.

The phenylalanine loading test in the differential diagnosis of dystonia

Neurology ◽  
2003 ◽  
Vol 60 (4) ◽  
pp. 700-702 ◽  
Author(s):  
O. Bandmann ◽  
M. Goertz ◽  
J. Zschocke ◽  
G. Deuschl ◽  
W. Jost ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Early Diagnosis ◽  
Loading Test ◽  
Generalized Dystonia ◽  
Phenylalanine Loading ◽  
Great Relevance ◽  
Treatable Condition

Early diagnosis of dopa-responsive dystonia (DRD) and its delineation from other dystonic syndromes is of great relevance because DRD is an eminently treatable condition. The possible relevance of the phenylalanine loading test (Phe-L) in differentiating DRD from primary focal and generalized dystonia was investigated. A marked difference in the phenylalanine/tyrosine ratio between patients with DRD and patients with other types of dystonia was observed. This indicates that Phe-L may be helpful in the differential diagnosis of dystonias.

STEROID METABOLISM IN THE PERFUSED HUMAN PLACENTA

1978 ◽  
Vol 87 (1) ◽  
pp. 181-191 ◽  
Author(s):  
Alfred S. Wolf ◽  
Klaus A. Musch ◽  
Werner Speidel ◽  
Jürgen R. Strecker ◽  
Christian Lauritzen
Keyword(s):  
Venous Blood ◽  
Placental Lactogen ◽  
Dehydroepiandrosterone Sulphate ◽  
Metabolic Capacity ◽  
Loading Test ◽  
Lower Range ◽  
Group I ◽  
High Concentrations ◽  
Steroid Precursor

ABSTRACT A new model for the perfusion of human term-placentas has been developed for studies on the placental biogenesis of C-18 and C-19 steroids. For viability criteria, the glucose- and oxygen-consumption, regional perfusion control by dye-infusions or scanning after injection of 99Tc-labelled macroparticles, and the histological qualification were chosen. The recycled perfusate was investigated for the steroids oestrone (Oe1), oestradiol-17β (Oe2), oestriol (Oe3), 4-androstene-3,17-dione (A), testosterone (T), and human placental lactogen (HPL) by radioimmunoassay in controls and perfusions with the foetal steroid precursor dehydroepiandrosterone sulphate (DHA-S). In control perfusions, steroid hormones were found in constant ratios (Oe1:Oe2:Oe3:T:A = 30:1.5:100:0.35:1). Following the administration of 10 mg DHA-S for testing the metabolic capacity of the organ, high concentrations of Oe1 (90–720 ng/ml = 250–3970 % as compared to 100% pre-injection values) were found, shortly preceded by a rapid increase of A (66–1000 ng/ml = 100–16 000 %). A typical surge of T (5.3–147 ng/ml = 265–4640 %) preceded the normally slower increment of Oe2 (22–220 ng/ml = 1570–4330 %). The concentrations of Oe3 and HPL remained nearly unchanged. From different steroid patterns after DHA-S-load, two distinct responses of term-placentas could be differentiated: Group I (n=12) showed high concentrations of Oe1 (3200 ± 940 %), a small increase of T (1020 ± 500%), as well as low and delayed values of Oe2 (1660 ± 450%). In Group II (n = 5), values were high for T (3160 ± 1020%) and Oe2 (3300 ± 1110%), whereas Oe1 was found in a lower range (508 ± 302%). In contrast to in vivo findings in maternal venous blood after DHS-S injection to the mother, oestrone was found in perfusions as the main oestrogen fraction from DHA-S. Thus, the analysis of such metabolic differences might be of help in the interpretation of complex results from the DHA-S-loading test.

STEROIDSTOFFWECHSEL BEI BRUSTKREBS. III.

1959 ◽  
Vol XXXII (I) ◽  
pp. 23-32 ◽  
Author(s):  
Kurt Schubert ◽  
Hans Schröder
Keyword(s):  
Advanced Cancer ◽  
Liver Damage ◽  
Adsorption Chromatography ◽  
Hepatic Insufficiency ◽  
Loading Test ◽  
Patients With Cancer ◽  
Urinary Steroids ◽  
Normal Women

ABSTRACT A testosterone test using two different dosages was carried out simultaneously in 7 women suffering from metastasizing carcinoma of the mamma and in 3 normal women. In each case the urinary steroids were estimated before the beginning of the test and after administration of 50 mg and 100 mg of testosterone respectively; the interval between the single estimations being one week. The use of fractionated hydrolysis enabled a mild fission of the conjugates and the classification of the products into free steroids, glucuronosides, sulfates and unknown conjugates. The 17-ketosteroids and the testosterone were estimated by means of Girard's separation and adsorption chromatography. During the loading test with testosterone different behaviours became evident, which had not been realized before. The behaviour of the 17-ketosteroids rendered possible the differentiation of normal women from patients with cancer of the breast yet without hepatic insufficiency, and furthermore of these latter ones from those with a liver damage in addition to the cancer of the breast. The glucuronosides of the 17-ketosteroids are only depressed, when there exists a pronounced damage of the liver; the loading test making possible an extension of the range of recognizable damages. Furthermore, the behaviour of dehydroepiandrosterone (II/III), of androsterone (IV), and of aetiocholanolone (V) lends itself to this differentiation. In advanced cancer of the breast the values of II/III are invariably low, whilst IV and V often increase temporarily. The relation of IV to V may be altered in a different way. The excretion of not transformed testosterone is less in patients than in normal women and especially low in patients with liver damage.

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