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Biomedical subjects

R Mercelis

Publications and source records attributed to R Mercelis.

12 recordsLinked to original sources
PubMed1991

Hereditary hepatic porphyria due to homozygous delta-aminolevulinic acid dehydratase deficiency: studies in lymphocytes and erythrocytes.

Activities of delta-aminolevulinic acid (ALA) dehydratase and porphobilinogen (PBG) deaminase, and haem content were determined in EB-virus transformed lymphocytes from two patients with homozygous ALA dehydratase deficiency, and their family members to determine the expression of the specific gene defect in this cell type. ALA dehydratase activity, but not PBG deaminase activity or haem content, was markedly decreased in lymphocyte preparations from both patients with homozygous enzyme deficiency, and moderately decreased in subjects heterozygous for enzyme deficiency. Immunochemical quantitation of erythrocyte ALA dehydratase suggested the presence of a cross-reactive material in a patient with a late-onset of acute hepatic porphyria due to the homozygous enzyme deficiency.

Adult↗
PubMed1990

Porphyric neuropathy and hereditary delta-aminolevulinic acid dehydratase deficiency in an adult.

A man without a history of porphyric attacks developed a subacute motor neuropathy at the age of 63. At the same time the first signs of a myeloproliferative disorder were found. He had a homozygous deficiency of erythrocyte delta-aminolevulinic acid dehydratase (ALA-D) with autosomal recessive inheritance. Treatment with parenteral glucose and with hematin had a beneficial influence on the plasma ALA levels. The finding of a motor neuropathy with increased plasma levels of ALA but not of porphobilinogen (PBG) supports the potential role of ALA in the pathogenesis of porphyric neuropathy.

Genetic Diseases, Inborn↗
PubMed1989

Biochemical diagnosis of an hereditary aminolaevulinate dehydratase deficiency in a 63-year-old man.

Porphyrin metabolism was investigated in a 63-year-old male patient who developed a subacute onset polyneuropathy with predominance of motor signs in the upper limb. The screening for lead, cadmium, mercury, aluminum and thallium was negative. The study of porphyrin metabolism showed remarkable abnormalities, particularly a very high level of plasmatic 5-aminolaevulinic acid contrasting with a normal level of porphobilinogen and a nearly complete loss of activity of aminolaevulinic acid dehydratase with no regenerative response to dithiothreitol or zinc ions. The other causes of aminolaevulinic acid dehydratase deficiency (tyrosinaemia, alcoholism, smoking, cirrhosis, renal insufficiency, diabetes mellitus) were ruled out. The diagnosis of primary aminolaevulinic acid dehydratase deficiency was proposed and confirmed by the familial study, which revealed the existence of several heterozygous members in this family.

Aluminum↗
PubMed1987

Myoadenylate deaminase deficiency: absence of correlation with exercise intolerance in 452 muscle biopsies.

A histochemical assay was routinely performed of myoadenylate deaminase (MAD) in muscle biopsy specimens. MAD was absent in 13 cases, i.e. 2.9% of the specimens. In 10 cases the deficiency was confirmed biochemically. The diagnoses in the 13 patients were: polyneuropathy (n = 5), infantile spinal muscular atrophy (n = 3), congenital myopathy with type 2 fibre atrophy, facioscapulohumeral myopathy, polymyositis, myotonic dystrophy and hyperornithinaemia with gyrate atrophy of the retina. In contrast, 35 unrelated patients presenting with exercise-related muscle cramps or pains showed normal histochemical MAD activity. The biopsy specimens in all of these patients were essentially normal and in none of them was the diagnosis of a neuromuscular disease made. The results failed to confirm the association of MAD deficiency with aches, cramps and pains or exertional myalgia.

AMP Deaminase↗
PubMed1986

Electromyography.

Explore the source record for details and available documents.

Cranial Nerves↗
PubMed1983

Cardiac manifestations of Becker-type muscular dystrophy.

The electro-, phonomechano- and echocardiographic manifestations observed in a family with documented X-linked Becker-type muscular dystrophy (BMD) are described. Important myocardial dystrophic lesions may occur in young patients with BMD. They are associated with typical electrocardiological findings which were described as a distinctive pattern in Duchenne-type muscular dystrophy. Myocardial involvement is seldom observed in heterozygotes for BMD.

Adult↗
PubMed1982

Neurophysiological studies in adrenomyeloneuropathy. A report on five cases.

Neurophysiological studies were performed in 5 patients in two families suffering from adrenomyeloneuropathy (AMN). The diagnosis was supported by electron microscopy of nerve twigs in all cases and by the demonstration in 2 cases of increased levels of saturated very long chain fatty acids in cultured fibroblasts (Moser, personal communication). Measurements of the sensory-motor conduction velocities demonstrated the variability of the peripheral nerve damage in AMN, further confirmed by quantitative studies of sensory nerve biopsies. Somatosensory evoked potentials (SEP) were abnormally delayed and their configuration was abnormal, mainly following stimuli applied to the lower limbs. Our data suggest a more severe involvement of the fasciculus gracilis and an extension of the lesions to the medial lemnisci in agreement with the few postmortem reports showing multifocal demyelination. Brain stem auditory evoked potentials (BAEP) were delayed, pointing towards lesions between cochlear nerve and superior olivary nucleus and also at lateral lemniscal level. Morphological confirmation is lacking but the close topographical relationship between the secondary auditory pathways and the medial lemnisci indicates that even small lesions could damage simultaneously both pathways. Neurophysiological studies contribute to the diagnosis of AMN, they confirm the inter- and intrafamilial variability of the clinical features and help to explain the signs and symptoms of this condition.

Adrenal Insufficiency↗
PubMed1981

Myoadenylate deaminase deficiency in a patient with facial and limb girdle myopathy.

Absence of AMP-deaminase was demonstrated by histochemical and biochemical methods in a muscle biopsy of a 25-year-old woman with facial and limb girdle myopathy. Venous ammonia failed to rise after ischaemic exercise. This patient further contributes to the variety of clinical pictures associated with AMP-deaminase deficiency. Whereas AMP-deaminase has been shown to play an essential role in the regulation of adenine nucleotide metabolism in the liver, its physiological function in muscle remains uncertain.

AMP Deaminase↗
PubMed1979

Arylsulphatases A and B in human diploid fibroblasts: differential assay with 4-methylumbelliferylsulphate and AgNO3.

A new technique is introduced for the differential assay of arylsulphatases A and B in centrifuged homogenates of cultured human skin fibroblasts, using 4-methylumbelliferyl-sulphate as a substrate and AgNO3 as a selective inhibitor of arylsulphatase A. The method can be applied in the diagnosis of metachromatic leucodystrophy, mucopolysaccharidosis type VI and mucosulphatidosis. Normal arylsulphatase activities were found in fibroblasts derived from patients with mucopolysaccharidoses types II, III-A and IV, known to be caused by deficiencies of various other sulphatases.

Cerebroside-Sulfatase↗
PubMedDate not supplied

Familial periodic paralysis with hypokalaemia. Study of a muscle biopsy in the myopathic stage of the disorder.

A 51 year-old male patient was affected by a dominantly inherited periodic paralysis. With large potassium supplements and ageing, the number and severity of attacks became considerably reduced. Increasing weakness and atrophy of the lower extremities were documented by clinical examination and by computer-assisted tomography of the muscles. A biopsy was taken in the vastus lateralis muscle without any attempt to induce a hypokalaemic paralytic attack. Light microscopy showed multiple intra- and extracellular vacuoles, rimmed vacuoles, myonecrosis, fatty degeneration and endomysial fibrosis. The endomysial nerve bundles were normal. Both fiber types were vacuolated. Quantitative studies revealed abnormal variability coefficients and increased atrophy factors for all types. Electron microscopy showed dilatations of the tubular system and of the sarcoplasmic reticulum communicating with large vacuoles limited by a single membrane. Other vacuoles were covered by a basement membrane and could contain collagen fibers or capillaries. Accumulation of myeloid bodies and of 10-13 nm filaments were also noted in the sarcoplasm. Cytoplasmic bodies were present. No tubular aggregates could be found. The nerve bundles were normal. These findings were in part similar to the ones reported by Gérard et al. (1978) in the son's biopsy during an induced paralytic attack. Significant findings in our case are the sequence of events leading to muscle fibre destruction, still detectable at an advanced stage of the disease. Myopathic changes represent a delayed but severe complication of the disorder.

Biopsy↗