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Biomedical subjects

M Duran

Publications and source records attributed to M Duran.

At least 271 records · Page 15Linked to original sources
PubMed1981

5-oxoprolinuria due to hereditary 5-oxoprolinase deficiency in two brothers--a new inborn error of the gamma-glutamyl cycle.

Two brothers, aged 16 and 11 years, had recurrent episodes of vomiting, diarrhoea and abdominal pain, starting in infancy. In spite of extensive investigations no cause of their enterocolitis could be established. After several years symptomatic treatment was discontinued without any recurrence of symptoms. Their father and several paternal relatives have had kidney stones. Both boys developed urolithiasis and an oxalate-containing stone was removed from the elder brother's kidney. He had no hypercalciuria. His glomerular and tubular function tests were normal. Gas chromatography of urine from both brothers revealed massive excretion of L-5-oxoproline (pyroglutamic acid). Glutathione levels in erythrocytes of both patients were normal. The activities of enzymes of the gamma-glutamyl cycle were analysed in erythrocytes, leukocytes and cultured skin fibroblasts. The level of glutathione synthetase was normal, as was the affinity of this enzyme for its substrate gamma-glutamyl-cysteine. Feedback inhibition of gamma-glutamyl-cysteine synthetase by glutathione was also normal. Both patients had a specific deficiency of 5-oxoprolinase, the activity of which was 2-4% of that of control subjects. Their parents had intermediate 5-oxoprolinase activities in fibroblasts, indicating a recessive mode of inheritance. Thus, 5-oxoprolinuria in these two patients was due to a lack of 5-oxoprolinase, i.e., a new inborn error in the gamma-glutamyl cycle.

Adolescent↗
PubMed1980

Chromatographic determination and mass spectrometric identification of gamma-glutamylphenylalanine, a urinary constituent in phenylketonuria.

The occurrence of gamma-glutamylphenylalanine in the urine of patients with phenylketonuria could be demonstrated using chromatographic techniques and mass spectrometry. Concentrations ranged up to 35 mg/l. Only a weak correlation between the urinary excretion of this compound and phenylalanine was seen. The ages of the patients investigated ranged from 2 weeks to 18 years. The origin of the dipeptide is discussed.

Adolescent↗
PubMed1980

Leigh's disease with decreased activities of pyruvate carboxylase and pyruvate decarboxylase.

In a patient with the clinical symptoms of Leigh's disease a partial deficiency of hepatic pyruvate carboxylase and pyruvate decarboxylase was found at necropsy. Cerebral pyruvate decarboxylase activity was also diminished. All enzyme activities were measured in total homogenates. The finding of typical necrotic lesions in the brain stem was consistent with the clinical diagnosis. During life moderate lactic acidaemia and no hypoglycaemia were observed, but an abnormal organic acid excretion pattern was present. The contribution of the enzyme defects to the aetiology of the disease is discussed.

Brain↗
PubMed1980

L-2-Hydroxyglutaric aciduria: an inborn error of metabolism?

A 5-year-old boy, excreting large amounts of 2-hydroxyglutaric acid in the urine (3.3-7.6 mmol/l), is described. The patient presented with psychomotor retardation and dystrophy. His skeletal age was delayed. The EEG was not well differentiated; it resembled that observed in 2-year-old children. There was a severe anaemia, which reacted well to iron supplements. The 2-hydroxyglutaric acid was found to have the L-configuration, as analysed by capillary gas chromatography of the O-acetylated di-(-)-2-butyl ester derivative. The relation of L-2-hydroxyglutarate excretion to known metabolic pathways is discussed.

Child, Preschool↗
PubMed1980

Inborn errors of molybdenum metabolism: combined deficiencies of sulfite oxidase and xanthine dehydrogenase in a patient lacking the molybdenum cofactor.

A patient suffering from a combined deficiency of sulfite oxidase (sulfite dehydrogenase; sulfite:ferricytochrome c oxidoreductase, EC 1.8.2.1) and xanthine dehydrogenase (xanthine:NAD+ oxidoreductase, EC 1.2.1.37) is described. The patient displays severe neurological abnormalities, dislocated ocular lenses, and mental retardation. Urinary excretion of sulfite, thiosulfate, S-sulfocysteine, taurine, hypoxanthine, and xanthine is increased in this individual, while sulfate and urate levels are drastically reduced. The metabolic defect responsible for loss of both enzyme activities appears to be at the level of the molybdenum cofactor common to the two enzymes. Immunological examination of a biopsy sample of liver tissue revealed the presence of the xanthine dehydrogenase protein in near normal amounts. Sulfite oxidase apoprotein was not detected by a variety of immunological techniques. The plasma molybdenum concentration was normal; however, hepatic content of molybdenum and the storage pool of active molybdenum cofactor present in normal livers were below the limits of detection. Fibroblasts cultured from this patient failed to express sulfite oxidase protein or activity, whereas those from the parents and healthy brother of the patient expressed normal levels of this enzyme.

Child, Preschool↗
PubMed1979

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↗
PubMed1979

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↗
PubMed1978

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↗
PubMed1978

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↗