French multi-centric study of 2000 amniotic fluid interphase FISH analyses from high-risk pregnancies and review of the literature

This prospective and multi-centric study confirms the accuracy and the limitations of interphase FISH and shows that any cytogenetics laboratory can perform this technique. With regard to the technical approach, we think that slides must be examined by two investigators, because the scoring may be subjective. The main problem with the AneuVysion kit concerns the alpha satellite probes, and especially the chromosome 18 probe, which is sometimes very difficult to interpret because of the high variability of the size of the spots, and this may lead to false negative and uninformative cases. The best solution would be to replace these probes by locus-specific probes. Concerning clinical management, we offer interphase FISH only in very high-risk pregnancies or/and at late gestational age because of the cost of the test. We think that an aberrant FISH result can be used for a clinical decision when it is associated with a corresponding abnormal ultrasound scan. In other cases, most of the time, we prefer to wait for the standard karyotype.

[Pharmacokinetics of dextromoramide in the surgical patient]

The pharmacokinetics of dextromoramide were studied in nine patients undergoing peripheral vascular surgery. All the patients were anaesthetised with thiopentone and vecuronium. After tracheal intubation, anaesthesia was maintained with 0.5 to 1.5 vol % halothane and a 60%-40% vol nitrous oxide-oxygen mixture. Once the patient's status was stable, a 0.8 mg.kg-1 bolus of dextromoramide was given intravenously. Blood samples were obtained 2, 5, 10, 30, 60, 90, 120, 180, 240, 300, 360, and 420 min afterwards by an arterial catheter. Dextromoramide serum concentrations were measured with high performance liquid chromatography after extraction with an original technique. The pharmacokinetic parameters were calculated by computer using TRIOMPHE. In five patients, a bi-exponential equation best fitted the results, whereas a tri-exponential equation was necessary for the other four. Mean elimination half-life was 215.3 +/- 78.4 min, and the apparent final volume of distribution was 0.58 +/- 0.20 l.kg-1. Hepatic extraction was low, as shown by a mean systemic clearance of 2.0 +/- 0.9 ml.kg-1.min-1. Liposolubility of this drug is the highest of all opiates, with a heptane/water partition coefficient of 12.3. These parameters demonstrate that, in the opiate drug group, dextromoramide has a place apart from the others.