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Biomedical subjects

S K Wadman

Publications and source records attributed to S K Wadman.

At least 109 records · Page 6Linked to original sources

Urinary excretion of methylated purines in man and in the rat after the administration of theophylline.

Chromatographic characteristics of urinary metabolites of theophylline were studied by two-dimensional thin-layer chromatography, high-performance liquid chromatography and gas chromatography--mass spectrometry. Quantitative date for the urinary metabolites of theophylline in asthmatic children are given. It was shown that 1,3-dimethyluric acid is the predominant excretory product. In addition, smaller amounts of 1-methyluric acid, 3-methylxanthine and unchanged theophylline were found. Excretory patterns after theophylline ingestion before and during the administration of allopurinol in asthma patients and in rats suggest the existence of three metabolic pathways of theophylline. The administration of this drug to a patient with xanthine oxidase of theophylline. The administration of this drug to a patient with xanthine oxidase deficiency resulted in the excretion of 1-methyluric acid in addition to 1,3-dimethyluric acid, 3-methylxanthine, 1-methylxanthine and unchanged theophylline. It was concluded that in man the oxidation of theophylline is not catalysed by xanthine oxidase.

Allopurinol↗

Urinary excretion of orotic acid, orotidine and other pyrimidines in a patient with purine nucleoside phosphorylase deficiency.

Urinary orotidine and orotic acid have been determined in a patient with purine nucleoside phosphorylase (PNP) deficiency under various dietary therapeutic conditions. For this purpose a new procedure for the analysis of both compounds has been developed, consisting of prefractionation with Dowex 1X8, followed by two HPLC steps on a micro Bondapak NH2 and a micro Bondapak C18 column. With this method normal as well as slightly elevated excretions of orotic acid have been found in our patient. No evidence was obtained for inhibition of OPRT by purine (deoxy)nucleosides as a cause of pyrimidine starvation. A significant increase of urinary orotidine was found after loading with allopurinol. For comparison excretory values in a patient with ornithine transcarbamylase deficiency and also in a patient with orotic aciduria type I are shown. The possible cause of the slight increase in urinary orotic acid in our patient has been discussed.

Allopurinol↗

Propionyl-CoA carboxylase deficiency with overflow of metabolites of isoleucine catabolism at all levels.

An 11-year old girl with spastic paraplegia and mental retardation has suffered from attacks of metabolic acidosis since the age of 18 months. "Ketotic hyperglycinemia" was diagnosed when she was 3 years old. Reinvestigation at 9 1/2 years included a two-day load with L-isoleucine, and propionyl-CoA carboxylase assay in cultured fibroblasts. The following compounds increased following the load: 3-hydroxypropionic acid, 2-methyl-3-hydroxybutyric acid, 2-ethylhydracrylic acid, 3-hydroxy-n-valeric acid, 3-oxo-n-valeric acid, 2-methyl-3-oxobutyric acid, 2-oxo-3-methylvaleric acid, 2-methyl-3-oxovaleric acid, N-tiglylglycine, methylcitric acid and butanone. Small amounts of alloisoleucine appeared in plasma. Propionyl-CoA carboxylase deficiency was suggested by this metabolite pattern and demonstrated in cultured fibroblasts.

Acidosis↗

Computer analysis of the EEG as an aid in the evaluation of dietetic treatment in phenylketonuria.

The effect on the EEG of the reintroduction of phenylalanine in the diet of 6 patients with PKU on treatment was studied. Patients received daily loads of 100 or 150 mg L-phenylalanine/kg, equally divided over the meals, and computerized spectral EEG analysis was performed. The following EEG changes were seen: (1) occurrence of activity in the low frequency band (2--5 c/sec), (2) change of frequency of dominant rhythms; (3) change in the degree of synchrony between identical frequencies, occurring in different derivations. EEG changes increased quantitatively parallel to increasing blood phenylalanine and reversed after stopping the phenylalanine administration, suggesting that the EEG abnormalities are a measure for the degree of intoxication caused by phenylalanine or its metabolites. It is suggested that the EEG data may be useful deciding to terminate the diet in PKU.

Adolescent↗

Simultaneous occurrence of xanthine oxidase and sulfite oxidase deficiency. A molybdenum dependent inborn error of metabolism?

In a 3-week old female child with clinical features including neurologic abnormalities and lens dislocation, xanthinuria co-existed with increased excretion of sulfur compounds (sulfite, S-sulfocysteine, taurine and thio-sulfate). Low xanthine oxidase and absent sulfite oxidase activities were found on liver biopsy. No abnormality was detected in either parent. Both the above enzymes are molybdenum-flavoproteins. Normal serum molybdenum concentration seemed to rule out dietary deficiency or impaired absorption. A defect in the incorporation of the metal into flavoproteins is postulated in this case.

Animals↗

Organic acid excretion in a patient with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency: facts and artefacts.

The organic acid excretion in a patient with 3-hydroxy-3-methylglutaryl-CoA lyase deficiency is described. In addition to 3-hydroxy-3-methylglutaric, 3-methylglutaconic, 3-methylglutaric and 3-hydroxyisovaleric acids, substantial amounts of glutaric and adipic acids were repeatedly observed. 3-Methylcrotonic acid and possibly one of its isomers was found to be formed artificially from 3-methylglutaconic acid.

Acyl Coenzyme A↗

Attempted dietary treatment of a boy with hyperammonemia due to ornithine transferase deficiency.

Dietary treatment of a male patient suffering from the delayed-onset type of OCT deficiency was attempted. Control of the hyperammonemia was attempted by restriction of protein intake, guided by monitoring the plasma ammonia and regular checking of the serum amino acid levels. The influence of supplementary citric acid or lactulose therapy on the plasma ammonia level was investigated and found to be negligible. The therapeutic effect of supplying ornithine and arginine (an essential amino acid in urea cycle disorders) is described. Despite intensive dietary treatment over two and a half years, a incorrigible hyperammonemic crisis resulted in the sudden death of our patient.

Amino Acid Metabolism, Inborn Errors↗

Methylmalonate excretion in a pregnancy at risk for methylmalonic acidaemia.

In a pregnant woman, who had given birth to a child with methylmalonic acidaemia previously, urinary methylmalonate was measured at various intervals in the second half of the pregnancy. A significant increase was observed towards term. The child proved to be affected. This procedure enabled the detection of an affected fetus in the third trimester of pregnancy. If a case of methylmalonic acidaemia is detected in this way, treatment can be started immediately after birth.

Female↗

Two-dimensional thin-layer chromatography for the screening of disorders of purine and pyrimidine metabolism.

A method is presented for the two-dimensional thin-layer chromatographic screening of purines, pyrimidines and their nucleosides in the urine. Prior to chromatography, isolation of these substances from the urine is performed by anion-exchange column chromatography. Purines and pyramidines are quantitatively eluted with formic acid 0.01 M and 4 M respectively. The results of recovery and stability experiments are given. Normal excretory patterns are presented. Also results in patients with various diseases are shown: ornithine transcarbamylase deficiency, adenosine deaminase deficiency, purine nucleoside phosphorylase deficiency, adenine phosphoribosyltransferase deficiency, xanthine oxidase deficiency and hypoxanthine-guanine phosphoribosyltransferase deficiency. Finally the pattern of a patient on treatment with allopurinol is given.

ATP Phosphoribosyltransferase↗

Lanthionine detected in human urine.

Lanthionine has been detected incidentally in the urine of a patient with an abdominal pseudo-tumor, possibly caused by a Yersinia infection. The L- and/or D-form together with the meso-form were present. The identity of the amino acid was confirmed by GC-MS of the N-trifluoroacetyl methyl ester derivative. The abnormal amino acid was thought to be not of endogenous origin. The possibility that it was produced by gut bacteria is considered.

Alanine↗