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Serge Amselem

Publications and source records attributed to Serge Amselem.

22 records · Page 2Linked to original sources

Current approaches for deciphering the molecular basis of combined anterior pituitary hormone deficiency in humans.

This review focuses on the general strategies currently used to decipher the molecular bases of combined pituitary hormone deficiency (CPHD) of genetic origin. By summarizing illustrative approaches that turned out to be successful for identifying an increasing number of genes involved in CPHD in the human, this article consider predictable obstacles specific to the investigation of these rare and heterogeneous conditions, while underlining the previously unsuspected roles of several of these genes during the development of extrapituitary structures.

Animals↗

Screening patients with prolonged neuromuscular blockade after succinylcholine and mivacurium.

UNLABELLED: Patients with pseudocholinesterase (BChE) variants may exhibit markedly prolonged paralysis after the administration of succinylcholine or mivacurium. We sought to evaluate to what extent molecular biology may contribute to the biological assessment of such patients. We conducted a prospective cohort study in patients referred to our center between 1995 and 1999 for prolonged neuromuscular blockade after mivacurium or succinylcholine. For each patient, phenotyping was performed with a conventional biochemical technique and molecular biology for the detection of the atypical mutation (A variant). Among the 36 patients referred, 31 had low BChE activity, 26 had received mivacurium (BChE activity, 2.1 U/mL; 0.3-4.3 U/mL), and 5 had received succinylcholine (BChE activity, 1.9 U/mL; 1.1-3.2 U/mL) (mean; extreme values). The mean clinical duration of paralysis was 90 min (40-140 min) after succinylcholine and 301 min (120-720 min) after mivacurium. Thirty-two patients had a BChE deficiency of genetic origin: 20 were homozygous (AA), 10 were heterozygous (UA) for the A variant, and 2 did not have the A mutation (UU). One heterozygous UA patient had normal BChE activity. Nine among the heterozygous UA and the two homozygous UU patients probably carried a not-screened variant. In most cases, biochemical diagnosis was sufficient to confirm the existence of constitutional deficiency; molecular biology improved the accuracy of diagnosis in 11 patients (30%) but had few or no clinical implications for the patient him- or herself. IMPLICATIONS: Systematic screening for the pseudocholinesterase atypical variant by biochemical and DNA analysis after a prolonged neuromuscular blocking effect of succinylcholine or mivacurium shows that molecular biology could improve the diagnosis in approximately one third of patients, but with few clinical implications, compared with biochemical testing.

Adolescent↗

Isolation and expression of the human hPF20 gene orthologous to Chlamydomonas PF20: evaluation as a candidate for axonemal defects of respiratory cilia and sperm flagella.

Primary ciliary dyskinesia (PCD) is a heterogeneous congenital disorder characterized by bronchiectasis and chronic sinusitis, sometimes associated with situs inversus (i.e., Kartagener's syndrome) and male infertility. At the cell level, the disease phenotype includes various axonemal abnormalities of respiratory cilia and sperm flagella. We have previously isolated DNAI1, the first gene involved in these diseases in patients lacking outer dynein arms. In this study, designed to find additional genes for other axonemal defects, we report the isolation of a novel human gene, hPF20, which is orthologous to Chlamydomonas pf20. The hPF20 gene is expressed as two major transcripts: one is expressed in testis only, whereas the second is weakly expressed in many other tissues. As flagella of Chlamydomonas strains carrying pf20 mutations lack the axonemal central complexes, we tested the involvement of the hPF20 gene in the disease phenotype of five patients in whom cilia or flagella display abnormal central complexes. Five intragenic polymorphisms were identified and used to exclude hPF20 in two consanguineous patients, while no mutation was found in the remaining patients. However, given the genetic heterogeneity of PCD, we consider that this gene remains a good candidate to be investigated in patients with abnormal central complexes.

Adult↗