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Biomedical subjects

U Grimm

Publications and source records attributed to U Grimm.

At least 37 records · Page 2Linked to original sources
PubMed1988

[Distribution of cystinuria subtypes in the Democratic Republic of Germany].

The classic cystinuria is a hereditary disorder characterized by a defective transport of cystine and the dibasic amino acids arginine, lysine and ornithine in the epithelial cells of the renale tubule and the gastrointestinal tract. The excretion patterns of cystine and the dibasic amino acids in 24-hour urine samples from heterozygotes can be used to the differentiation between the genetic subtypes. 120 probands in the age range from 3 to 70 years from 22 families with cystinuria were investigated by thin-layer chromatography and by ion exchange chromatography. In patients with cystinuria the genotype I-I has a frequency of 50%. These results and the distribution of the other subtypes are in accordance with published data. From 98 persons investigated in 22 families with cystinuria 14 run the risk to form cystine stones. Therefore, the knowledge of the subtypes is relevant for practice.

Adolescent↗
PubMed1988

Increased concentrations of tyrosine and phenylalanine in the cerebrospinal fluid as a possible reflection of related changes of the brain tissue in newborns with intra-uterine growth retardation.

Plasma and cerebrospinal fluid concentrations of tyrosine and phenylalanine were measured fluorometrically in human term neonates appropriate for gestational age and in neonates small for gestational age with severe intra-uterine growth retardation of Type II. The intra-uterine retarded newborns showed significant differences of both plasma and cerebrospinal fluid tyrosine levels as compared with the non-retarded newborns: the mean plasma and cerebrospinal fluid tyrosine were determined to be 2.0 and 2.5 times, respectively, higher in the retarded group. The mean cerebrospinal fluid phenylalanine content was also increased in these newborns. The findings may reflect cellular disturbances of the tyrosine metabolization in the developing brain as it can also be found in experimental intra-uterine growth retarded animals.

Biomarkers↗
PubMed1988

[Studies on tryptophan metabolism in calcium oxalate urolithiasis].

In 90 patients with calcium oxalate urolithiasis an oral tryptophan-loading test with 5 g L-tryptophan was performed and the 24-hour urinary excretion of xanthurenic acid and kynurenine was measured. In 10 cases pathological deviations and an excretion pattern of tryptophan metabolites via kynurenine similar as in the hereditary vitamin-B6-dependent xanthurenic aciduria in homozygous or heterozygous from were found. Correlations between the oxalate excretion and the tryptophan metabolism do not exist. A 2-year therapy with 60 mg vitamin B6 was favourable in patients with an excretion of more than 300 mumol XA after a tryptophan load.

Administration, Oral↗
PubMed1987

Arylsulphatase C activity in leukocytes of patients and carriers of X-linked ichthyosis.

In Triton X-100 solubilized leukocytes of 17 patients and 8 obligate carriers of X-linked recessive ichthyosis (XLI) the activity of arylsulphatase C (ASC) was determined and expressed as the ratio to beta-galactosidase activity. The ASC/beta-gal ratio of XLI patients is markedly decreased (range 0.07-0.48) in comparison to the corresponding control group of males (range 1.3-2.7). The enzyme ratios of 8 obligate carriers of XLI are decreased (range 0.90-1.9) in comparison to the normal females (2.13-5.52). These results indicate that the determination of the enzyme ratio of ASC/beta-gal in Triton X-100 solubilized leukocytes is a sensitive test for biochemical identification of patients and probably of carriers of XLI.

Arylsulfatases↗
PubMed1986

[Occurrence of phenylalanine hydroxylase in the human kidney].

Phenylalanine hydroxylase activity, determined by fluorimetric procedure in human kidney (cortex) of 17 patients, who had a kidney operation, was on the average 4.7 nkat tyr/g protein (25 degrees C), which is 28% in comparison to the enzyme activity in human liver. This is in good accordance with the results of AYLING et al. who investigated 15 human kidneys. They found by the spectrophotometric method 22% of the liver enzyme activity. A nonspecific hydroxylation could be excluded by tests with the inhibitors p-Cl-phenylalanine, 3-I-tyrosine and 6-F-tryptophan.

Adult↗
PubMed1984

On the brain barrier system function and changes of cerebrospinal fluid concentrations of phenylalanine and tyrosine in human phenylketonuria.

In 6 patients with classic phenylketonuria (PKU) the plasma and cerebrospinal fluid (CSF) concentrations of phenylalanine and tyrosine were measured fluorimetrically. The results of the PKU group were compared with data obtained from 17 children without abnormal CSF parameters and free of metabolic or central nervous disorders, in whom a diagnostic lumbal puncture has been performed. The PKU patients showed statistically significant differences in comparison with the controls: plasma and CSF phenylalanine contents were markedly higher (on the average 6.4 and 4.6 times, respectively) in PKU patients. Plasma tyrosine was 1.8 times lower, but CSF tyrosine was about 2.2 times higher in comparison to the controls. In general, the plasma CSF-ratio ( PLR ) of phenylalanine did not change in PKU and could be found in the same range as in the normal controls. In contrast to this, the PLR of tyrosine was found to be significantly lower in PKU patients. The results are discussed with respect to an altered function of the brain barrier systems for the amino acid transport in PKU, and that increased CSF tyrosine contents in PKU may rather reflect disturbances of the intracellular metabolism of the brain cells than changes of the amino acid transport through the brain barrier produced by hyperphenylalaninemia.

Blood-Brain Barrier↗
PubMed1983

[Detection of phenylalanine hydroxylase activity in leukocytes and fibroblasts].

Phenylalanine hydroxylase activity measured in leucocytes and fibroblasts by the fluorometric method is nonspecific and can be released by other aromatic hydroxylases. Investigations with the inhibitors p-Cl-phenylalanine, 3-I-tyrosine and 6-F-tryptophan made evident that these results may be caused by the tryptophan hydroxylase and the tyrosine hydroxylase. Phenylalanine hydroxylase activities in leucocytes could also not be measured by radiochemical investigations with [3-14C] phenylalanine (scanner and liquid scintillation technique).

Fibroblasts↗