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Biomedical subjects

L Cathelineau

Publications and source records attributed to L Cathelineau.

At least 19 recordsLinked to original sources
PubMed1995

[Bronchopulmonary dysplasia: outcome and treatment of severe forms].

BACKGROUND: The outcome of severe forms of bronchopulmonary dysplasia (BPD) leading to a prolonged dependence on mechanical ventilation (MV) and/or oxygen therapy (O2) is not evaluated, and factors of guidance to treatment are not established. POPULATION AND METHODS: The medical records of 49 infants, born between 1982 and 1990, with BPD who required MV and or O2 after 12 months of life were retrospectively reviewed. Three groups of infants were defined: group I: 26 infants on MV since birth; group II: seven infants weaned from MV after the first month of life then put back on MV belatedly; group III: 16 infants on spontaneous ventilation (SV) under O2. RESULTS: At 12 months of age, the 49 infants showed sleep hypoxemia, failure to thrive and 28% of them pulmonary hypertension. Comparison between MV and O2 infants indicated that subjects on MV had pulmonary dynamic compliance (Cl dyn) lower than 50% (p = 0.01), ventilatory work including respiratory frequency in rest > 40 cycles/min; 70% of them had asynchronous thoracic and abdominal muscles during sleep (p < 0.01 for all comparisons). Seventy percent of patients had bronchospasms (p = 0.02). The 49 infants had a favourable outcome, allowing weaning from MV or O2 between the ages of 2 and 4 years. CONCLUSIONS: These findings suggest that major respiratory failure in prematurely born infants can be overcome with prolonged respiratory and nutritional supports during the post-natal period of lung development; Cl dyn < 50% is a cursor for prolonged MV and weaning from MV should be excluded as long as increased ventilatory work persists.

Bronchopulmonary Dysplasia↗
PubMed1988

Immunochemical analysis of nineteen ornithine transcarbamoylase deficiencies.

Western blot analysis of 19 human ornithine transcarbamoylase (OTC) deficiencies characterized by neonatal (13 patients: type I) or later onset of symptoms (6 patients: type II) are reported. All the patients studied here are hemizygous males. In the first group, most of the patients had no residual enzymatic activity (11 patients). In 8 cases this is correlated with a complete absence of protein, in 1 patient with a much reduced amount and in 2 others with 80% of an OTC-related protein of normal molecular weight. Only 2 patients with neonatal onset of symptoms had a detectable OTC activity which ranged from 0.5 to 1% of the control. Among the second clinical group of 6 patients with later onset of symptoms, the residual OTC activity was between 5 and 20% at pH 8.0; 3 of them had abnormal kinetics and 50% an OTC-related protein.

Humans↗
PubMed1986

Kinetic abnormalities of carbamyl phosphate synthetase-I in a case of congenital hyperammonaemia.

A sensitive direct colourimetric method has been employed to measure kinetic parameters and pH dependence of carbamyl phosphate synthetase-I, in a liver sample from a 2 1/2-month-old girl, who died from complications of a late-developing congenital hyperammonaemia. The residual activity of carbamyl phosphate synthetase-I was 25%, whereas other urea cycle enzymes were within normal range. Apparent Km for ammonium ion (0.73 mmol/L) was significantly increased (normal range 0.24-0.51). Km for bicarbonate ion was normal, while Km for NAG showed a slight variation from normal. The pH dependence curve of the patient's enzyme was flat, as compared to two controls showing pH optima at 7.8. Radial immunodiffusion (Mancini) of the abnormal enzyme against human enzyme antiserum gave a cross-reacting material of 10-20%. The methodological approach presented can be used to characterize abnormal enzymes in cases of partial deficiency with only 100-200 mg of liver tissue.

Amino Acid Metabolism, Inborn Errors↗
PubMed1986

Effects of organic acids on the synthesis of citrulline by intact rat liver mitochondria.

Citrulline synthesis, mostly regulated at the carbamoyl-phosphate synthase I (EC 6.3.4.16) step by the intramitochondrial concentration of ATP and/or N-acetylglutamate is tested with four organic acids: propionate, alpha-ketobutyrate, dipropyl-acetate and 4-pentenoate. In the presence of 10 mM succinate, as the oxidizable substrate, citrullinogenesis was only inhibited by propionate and 4-pentenoate. With 10 mM L-glutamate, a significant inhibition was observed with the four acids. After the addition of ATP and N-acetylglutamate to uncoupled mitochondria, no inhibition could be demonstrated with dipropylacetate and 4-pentenoate. However, a slight inhibition remained with propionate and alpha-ketobutyrate. When mitochondria were incubated with 10 mM L-glutamate, ATP decreased with propionate, dipropylacetate and 4-pentenoate. Under the same conditions, N-acetylglutamate synthesis was strongly inhibited by each organic acid. The decrease of N-acetylglutamate synthesis was related to the constant diminution of intramitochondrial acetyl-coenzyme A (CoA) and to the increase of propionyl-CoA with propionate and alpha-ketobutyrate. Acetyl-CoA and propionyl-CoA are respectively substrate and competitive inhibitor of the N-acetylglutamate synthase (EC 2.3.1.1). Each acid displayed its optimum inhibition at concentrations between 1 and 2 mM. At these acid concentrations, mitochondria had the lowest acetyl-CoA content and the highest propionyl-CoA content.

Acetyl Coenzyme A↗
PubMed1985

Impairment of citrulline synthesis during late pregnancy and lactation in rats.

Synthesis of citrulline by rat liver mitochondria was investigated during late pregnancy and early lactation. It was strongly decreased over all the period studied except during delivery, where a sudden rise was observed. The mitochondrial enzymes carbamoylphosphate synthetase I (ammonia) (EC 6.3.4.16) and ornithine carbamoyltransferase (EC 2.1.3.3) did not fall significantly during this period, although carbamoylphosphate synthetase I (ammonia) was slightly decreased antepartum. Citrulline synthesis was found significantly correlated to N-acetylglutamate concentration in mitochondria throughout the period considered. On the other hand, low levels of N-acetylglutamate could be explained by low activity of N-acetylglutamate synthase (EC 2.3.1.1).

Acetyltransferases↗
PubMed1985

Prenatal exclusion of ornithine transcarbamylase deficiency by direct gene analysis.

Direct gene analysis was used in the prenatal exclusion of ornithine transcarbamylase (OTC) deficiency; karyotyping the family's previously affected child had already identified the defect as a small deletion. A cloned OTC gene and two other X chromosome-specific probes were mixed, and hybridised to fetal DNA obtained from cultured amniocytes; the fetus was shown to be a normal male.

Adult↗
PubMed1985

Gene for OTC: characterisation and linkage to Duchenne muscular dystrophy.

Cloned coding sequences for rat and human ornithine transcarbamylase (OTC) were obtained by screening a rat and a human cDNA library respectively with a synthetic oligonucleotide corresponding to 27 bases of the rat sequence. These clones, 1100 bp long for the rat clone and 1300 bp for the human, contain approximately 80% of the human OTC coding sequence. The OTC mRNA length determined by Northern blot analysis is 1700bp. The human OTC sequence was shown to be localised Xp11.4-Xp21 using somatic cell hybrids. There is a frequent RFLP revealed with the restriction enzyme MspI. OTC is located more closely to the Duchenne muscular dystrophy mutation than previously reported markers such as RC8 and L1.28, and therefore should prove useful in carrier detection and haplotype analysis of families carrying the mutation causing the disease.

Animals↗
PubMed1985

Ornithine transcarbamylase and disaccharidase activities in damaged intestinal mucosa of children--diagnosis of hereditary ornithine transcarbamylase deficiency in mucosa.

Ornithine transcarbamylase (OTC) and disaccharidase activities were measured in the intestinal mucosa from 182 children. Sixty-nine had normal mucosa, whereas the others had different degrees of mucosal damage. Brush border disaccharidases are significantly decreased in all degrees of villous atrophy. In contrast, OTC is not affected in moderate atrophy and only slightly decreased in severe atrophy. Consequently, the OTC-to-lactase ratio increases with the degree of atrophy and permits discrimination between normal and damaged mucosa. The assay of OTC activity in intestinal mucosa for the diagnosis of hereditary deficiency in male hemizygote patients generally provides nonambiguously low results, whereas in heterozygote females the amount of residual activity is in the range of the results found in damaged mucosa.

Child↗
PubMed1984

Chronic vomiting in a case of citrullinaemia detected after treatment by total parenteral nutrition.

We report a case of a 56 year old woman who presented with a long history of chronic attacks of vomiting. On admission to hospital she was cachectic, and attempted parenteral nutrition induced coma. The illness was found to be due to citrullinaemia, a metabolic disorder of the urea cycle. Our patient is the oldest with this disorder so far described in the literature. The main points of the case and its investigation are outlined: hyperammonaemia, amino acid chromatogram, measurement of enzyme activity in skin and liver biopsy material. The therapeutic measures which led to cure are of particular interest.

Amino Acid Metabolism, Inborn Errors↗
PubMed1983

Cell-free synthesis and transport of precursors of mutant ornithine carbamoyltransferases into mitochondria.

Synthesis, mitochondrial transport and processing of ornithine carbamoyltransferase (EC 2.1.3.3) were studied in mutant mice strains (sparse-fur, spf, and sparse-fur with abnormal skin and hair, spf-ash) which exhibit a deficiency in this enzyme. Spf mice have an increased amount (about 150% of control) of the enzyme with abnormal kinetic properties, whereas spf-ash mice have a decreased amount (about 10% of control) of the enzyme with apparently normal kinetic properties. Precursors of the mutant enzymes were synthesized in a reticulocyte lysate cell-free system. The hepatic level of translatable mRNA coding for the enzyme and the rate of the enzyme synthesis in liver slices of spf mice were 58 and 60% of the controls, respectively. In the case of spf-ash mice the activity of translatable mRNA for the enzyme was 10% of the controls. These results indicate that the decreased amount of ornithine carbamoyltransferase protein in spf-ash mice is due mainly to a decreased level of translatable mRNA for the enzyme, whereas the increase in the enzyme amount in spf mice is presumably the result of a decreased rate of enzyme degradation. The subunit molecular weight of the spf enzyme precursor was practically the same as that of the normal enzyme precursor (Mr 40 000). Both precursors synthesized in vitro could be taken up and processed similarly to an apparently mature form (Mr 37 000). In the case of spf-ash enzyme, two discrete in vitro products were observed on sodium dodecyl sulfate polyacrylamide gel; one comigrated with the normal enzyme precursor and the other moved slightly slower. Both products appeared to be taken up and processed to the mature form of the enzyme.

Animals↗
PubMed1983

Radioisotopic assay of picomolar amounts of coenzyme A.

A two-step method of determining reduced coenzyme A (CoASH) concentrations in tissue or cell extracts is described. In the first step, CoASH is reacted with acetylphosphate in a reaction catalyzed by phosphotransacetylase to yield acetyl-CoA. Acetyl-CoA is then condensed with [14C]oxaloacetate by citrate synthase to give [14C]citrate. This method allows the measurement of 10-200 pmol of CoASH. By omitting the phosphotransacetylase step, measurement of the same amount of acetyl-CoA is possible.

Acetyl Coenzyme A↗
PubMed1983

Developmental changes of citrullinogenesis, mitochondrial N-acetylglutamate content and N-acetylglutamate synthetase in fetal and neonatal rats.

A low citrullinogenesis (less than 60 per cent of the adult value) was observed throughout the suckling period when mitochondria isolated from newborn rat liver were incubated in vitro with L-glutamate or succinate as oxidizable substrates. The adult value was reached after weaning. From birth to weaning, intact mitochondria synthesized more citrulline when supplemented with L-glutamate than with succinate. The low citrullinogenesis could not be explained by low carbamoylphosphate synthetase-I and ornithine transcarbamoylase activities that reached adult values at birth. The decreased citrullinogenesis seen for the first three days of life seemed to be related to the low intramitochondrial concentration of N-acetylglutamate, an activator of the carbamoylphosphate synthetase-I. The concentration of this activator did not differ from that reported for adult rat liver mitochondria after the fourth day of life. The discrepancy between the normal value of N-acetylglutamate concentration and the low activity of the N-acetylglutamate synthetase (15 to 30 per cent of the adult activity) is discussed on the basis of acetyl-CoA or L-glutamate availability in mitochondria isolated from newborn or young rats.

Acetyltransferases↗