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Biomedical subjects

H Bellet

Publications and source records attributed to H Bellet.

At least 37 records · Page 2Linked to original sources
PubMed1996

Treatment with vigabatrin may mimic alpha-aminoadipic aciduria.

PURPOSE: We describe a secondary effect of treatment with vigabatrin (VGB). A significant increase in alpha-aminoadipic acid (AAA) occurred in plasma and urine of VGB-treated children, thus mimicking a known rare metabolic disease, alpha-aminoadipic aciduria (AAAuria). METHODS: We studied eight children, aged from 3 months to 5 years, who were receiving VGB for drug-resistant partial epilepsies. Plasma and urine amino acids were assayed with ninhydrin detection on an automated Beckman 6300 analyzer. RESULTS: In eight out of eight children, there was a significant increase of AAA in plasma and in urine. Plasma values ranged from 7 to 8 microM (control values, < 5) and urinary values from 67 to 274 mmol/mol creatinine (control values, < 25). CONCLUSIONS: The concentrations of AAA in these VGB-treated children were as high as the concentrations found in the inherited metabolic disease, AAAuria. This could lead to incorrect diagnosis and to inappropriate genetic counseling. Thus whenever a genetic metabolic disease is suspected, amino acid chromatography testing should be performed before initiation of treatment with VGB.

2-Aminoadipic Acid↗
PubMed1995

Lafora disease is not linked to the Unverricht-Lundborg locus.

Lafora disease and Unverricht-Lundborg disease are two forms of progressive myoclonus epilepsies (PME). Recently the gene for Unverricht-Lundborg disease (EPM1) was mapped to chromosome 21q22.3. Using three highly polymorphic DNA markers (D21S212, PFKL, and D21S171) which flank the EPM1 locus, we performed linkage analysis to investigate whether or not the EPM1 gene is also implicated in Lafora disease. Linkage was excluded in three North-African pedigrees each comprising at least two affected individuals. This result suggests that differential diagnosis of Lafora disease and Unverricht-Lundborg disease may be facilitated by molecular genetic analysis.

Adolescent↗
PubMed1994

Benign infantile familial convulsions are not an allelic form of the benign familial neonatal convulsions gene.

Benign infantile familial convulsions (BIFC) and benign familial neonatal convulsions (BFNC) are two forms of familial convulsions having an age of onset within the first year of life. The gene responsible for BFNC has been mapped to chromosome 20q in the close vicinity of D20S19 and D20S20 markers. We performed linkage analysis between BIFC and D20S19-D20S20 in eight families in order to know whether the BFNC gene is also implicated in BIFC. Several apparent obligate crossovers between affected members were detected. The data here presented demonstrate that the BFNC gene is not responsible for BIFC.

Age of Onset↗
PubMed1994

[Effect of the age and the sex on plasma concentration of amino acids].

The effects of age and sex on the plasma free amino acid pattern of healthy men and women aged from 80 to 100 years were compared with those in younger adults (20 to 45 years old). Plasma amino acid concentrations were determined by ion-exchange chromatography on a 6300 Beckman analyzer. The plasma concentrations of valine, leucine, isoleucine, proline, glutamine + glutamic acid and phenylalanine were higher in males than in females. Citrulline, half-cystine, histidine, glutamine+glutamic acid, lysine, ornithine and phenylalanine plasma concentrations and the total plasma amino acids were higher in elderly than in younger subjects.

Adult↗
PubMed1991

Activity of citrulline malate on acid-base balance and blood ammonia and amino acid levels. Study in the animal and in man.

An experimental evaluation of citrulline malate (Stimol, CAS 54940-97-5), an anti-fatigue compound, was undertaken in man and in the animal in order to study the pharmacological activity of the substance at hepatic and renal level. In man, the protocol involved a double-blind randomized, placebo-controlled cross-over technique. The study in the animal was blind and placebo-controlled with two randomized parallel groups. Results showed that citrulline malate stimulates hepatic ureogenesis and favorizes the renal reabsorption of bicarbonates. These metabolic actions had a protective effect against acidosis and ammonia poisoning and explain the anti-fatigue properties of citrulline malate in man.

Acid-Base Equilibrium↗
PubMed1990

Germinal mosaicism from grand-paternal origin in a family with Duchenne muscular dystrophy.

We have identified a Duchenne muscular dystrophy (DMD) pedigree with an unexpected pattern of inheritance. Using marker restriction fragment length polymorphisms detected by probes that lie within and outside the DMD gene, we could demonstrate that the maternal grandfather has transmitted two distinct types of X chromosomes to his offspring. This original observation may be explained by postulating that the DMD mutation must have occurred during mitosis in early germline proliferation, leading to a germline mosaicism within this male ancestor.

DNA Probes↗
PubMed1990

Cystic fibrosis typing with DNA probes and screening for delta F508 deletion in families from southern France.

A sample of 235 individuals from 49 French cystic fibrosis (CF) families with at least one living affected child was typed with probes for restriction fragment length polymorphisms (RFLPs) known to be linked to the CF gene, and was screened for the delta F508 mutation. Using a combination of six probes, 44 out of the 49 families were sufficiently informative to enable prenatal diagnosis or carrier determination. As in many other populations, linkage disequilibrium was found between the CF locus and the haplotype B (XV2c: allele 1; KM19: allele 2), which accounts for about 78% of CF chromosomes in our families. The delta F508 deletion was present in 64.3% of CF chromosomes.

Chromosome Deletion↗
PubMed1989

[Detection of deletions by the amplification of exons (multiplex PCR) in Duchenne muscular dystrophy].

The polymerase chain reaction is a new powerful method for in vitro cloning of specific regions of DNA. The use of the heat-stable DNA polymerase made the reaction amenable to automation. This method greatly facilitates the detection of mutations which are responsible for Duchenne muscular dystrophy, via DNA amplification of multiple deletions prone exons from the DMD gene.

Chromosome Deletion↗
PubMed1987

[Transient symptomatic neonatal hyperammonemia].

Premature newborns suffering from respiratory distress and asphyxiated term newborns may present transient symptomatic neonatal hyperammonemia associated with reversible neonatal coma. As they survive they may develop normally; however the authors emphasize the importance of concomitant hemodynamic disorders and the extreme frequency of brain hemorrhage and ischemia. Ultrasonography or tomodensitometry are necessary for prognosis.

Ammonia↗
PubMed1986

A paediatric case of sideroblastic anaemia. Ultrastructural studies of erythroblasts cultured from marrow BFU-E in a methylcellulose micromethod.

We examined the morphological and functional characteristics of erythroblasts derived from marrow erythroid progenitor cells grown in a methylcellulose microculture, which were taken from a female child with rare atypical sideroblastic anaemia (SA) partially responsive to pyridoxine. Colony formation was within the normal range in three successive cultures (median values: 82.25 CFU-E and 16.4 BFU-E derived colonies/6.6 X 10(4) cells) compared to growth by normal cells (65-315 CFU-E and 9-40 BFU-E). We evaluated in vitro differentiation by biochemical microassay of a cytosol enzyme involved in the haem pathway: uroporphyrinogen I synthase (UROS). The UROS values in the erythroid colonies from SA marrow were at the lowere end of the normal range (median values: 6.7 +/- 0.3 and 14.4 +/- 3.8 pmol uroporphyrinogen/h in CFU-E and BFU-E-derived colonies respectively versus 17.4 +/- 7.3 and 25 +/- 7.2 pmol/h in CFU-E and BFU-E colonies from normal subjects. Ultrastructural examination of the SA erythroblasts from non-cultured bone marrow or derived from cultured BFU-E revealed the characteristic deposition of iron in mitochondria around the nucleus of most cells (ringed sideroblasts). However, the majority of cultured cells had marked dyserythropoietic features, with a large number of bilobulated or trilobulated erythroblasts, multiple cytoplasmic vacuoles, numerous abnormalities of the nucleus, and excessive membrane material beneath the plasma membrane, all features difficult to observe in non-cultured marrows.

Anemia, Sideroblastic↗
PubMed1985

[Urinary excretion of 3-methylhistidine. Value and application to the study of protein catabolism].

The urinary excretion of 3-methylhistidine (3 MH) is considered an easy and reliable method to quantify muscle protein catabolism in man. The 3 MH/creatinine (Cr) ratio is thought to be a good index of fractional degradation of muscle fibre protein. In the present article, the stress is placed on the limitations of 3 MH assays an- on their clinical applications. In thyroid diseases and in malnutrition (anorexia nervosa), the 3 MH/Cr ratio differentiates clearly marasmic malnutrition without increase in protein catabolism from hypercatabolic states, such as hyperthyroidism, with excessive protein degradation. 3 MH measurements therefore appear to be useful to determine the contribution of protein catabolism to lean mass reduction.

Adolescent↗
PubMed1985

Uroporphyrinogen I synthase assay as an evaluation of the in vitro development of human BFU-E and CFU-E.

We describe a simple spectrophotometric microassay to quantify the proliferation and the differentiation of human bone marrow or blood erythroid progenitor cells CFU-E and BFU-E. These precursors give rise, in culture, to colonies and bursts with markedly variations in size and hemoglobinization, which cannot be accurately evaluated by the usual method of scoring. We then developed a sensitive biochemical microassay to measure the uroporphyrinogen I synthase activity of progenitors grown in small wells. This assay is a valuable index of erythroid differentiation in vitro. This method can offer the opportunity to test the efficiency in vitro of various therapeutic agents in patients with hemopoietic disorders.

Ammonia-Lyases↗
PubMed1984

Thyroid status and muscle protein breakdown as assessed by urinary 3-methylhistidine excretion: study in thyrotoxic patients before and after treatment.

Urinary 3-methylhistidine (3MH) excretion was studied in nine thyrotoxic patients before and after treatment. Urinary creatinine (Cr) output was also measured and was low in the thyrotoxic subjects before treatment. Thus, although urinary output of 3MH was not greater than among the control population when expressed per subject, it was significantly elevated when expressed as the ratio of 3MH to Cr; this ratio fell significantly, reaching normal control values after a euthyroid state was obtained. In one patient who became hypothyroid, the 3MH/Cr ratio fell under the control value. There was a significant linear correlation between the 3MH/Cr ratio and the hormonal variables (T3, T4, FT4l); moreover, variations in the 3MH/Cr ratio and variations in the T3 level were closely correlated. 3-Methylhistidine appears to be a reliable index of muscular breakdown in thyrotoxicosis. From our results, it can be concluded, first of all, that hyperthyroidism is accompanied by an increased muscular catabolism, and, second, that the return to a euthyroid state results in an immediate normalization of muscular breakdown.

Adult↗
PubMed1982

Study of human isoferritins from liver, spleen, heart and placenta by the microcomplement fixation technique.

Ferritin, iron storage protein, presents two types of subunits, H and L, the respective proportions of which varying with the tissue of origin and defining molecules called isoferritins. This work attempts to compare four human ferritins (from liver, spleen, heart and placenta) by means of the microcomplement fixation technique. Results show that placenta and liver ferritins are closely related, while slight but significant differences appear between liver, spleen and heart ferritins. These differences are obviously less important compared to those observed between ferritins from different species of origin, as shown by the results expressed in terms of index of dissimilarity or immunological distance. Those results are fully consistent with the elementary aminoacid composition as well as with the relative proportions of H and L subunits among the various types of human isoferritins we have studied.

Animals↗