Changes in human high density lipoproteins in patients with extra-hepatic biliary obstruction.

Plasma high density lipoproteins (HDL) from patients with obstruction of the common bile duct were studied by crossed immunoelectrophoresis and isoelectric focusing. All cholestatic HDL fractions were rich in phospholipids (51.5 +/- 9%) with high proportions of free cholesterol (13.8 +/- 1.5%). Moreover, crossed immunoelectrophoresis of sera against anti-Apo A revealed the presence of multiple immunoprecipitates sharply contrasting with the pattern formed by normal sera. Tandem crossed immunoelectrophoresis against anti-Apo A and anti-Apo B was performed with whole serum and with the HDL fraction from various cholestatic subjects. Crossed identity was observed for two of these precipitates, which could be explained by the decrease in HDL stability due to the detergent effect of bile salts. The most noteworthy changes found in cholestatic patients appeared to be the apolipoprotein pattern of HDL. Both Apo AI (48%) and Apo AII (5.5%) were greatly diminished and Apo E was present in remarkably high amounts (39%) with two additional isoforms (Apo E'1 and Apo E'2).

[Molecular genetics: pre- and post-analytic "best practices"]. / Génétique moléculaire: les << bonnes pratiques>> pré-et postanalytieques.

Medical prescriptions for molecular genetic analyses are not yet very common in general practice, neverless they are becoming more and more frequent, and therefore it is more difficult to deal with them in part because of the recent french rules. Laboratory managers are supposed to be able to deal with such requests. This document, describing good laboratory practices, has been elaborated by members of the group "molecular genetics" from the "College National de Biochimie des Hôpitaux", providing details about: assessment of the prescriptions, including patient's consent, choice of the executing laboratory, specimen transmission, assessment and control of clinical and biological data, results transmission, confidentiality, archiving system. Such recommendations should facilitate exchanges with specialized laboratories, being specifically approved for practicing such analyses. The authors draw the attention of laboratory managers to the specificities of such requests.

[Apolipoprotein E and bleomycin hydrolase. Polymorphisms: association with neurodegenerative diseases]. / Maladies neurodégénératives et polymorphisme des gènes de l'apolipoprotéine E et de la bléomycine hydrolase.

Several studies indicate a possible association between different genes and chronic neurodegenerative diseases including Alzheimer's disease (DTA). To further investigate, we have analyzed association between the apolipoprotein E (apo E) and bleomycin hydrolase (BH) polymorphisms and three groups of elderly patients: control subjects (T) (n = 68), late-onset sporadic DTA patients (DTAst) (n = 65) and other non vascular neurodegerative diseases (MNDA) (n = 52). Apo E-epsilon4 and BH-G alleles frequencies (%) are: 8.2 (T), 31.5 (DTAst), 16.4 (MNDA) and 41.4 (T), 35.6 (DTAst). No association has been observed between carrying the G allele and DTA in epsilon4 negative subjects but, our data have confirmed the earlier reports: carrying the epsilon4 allele is a dose-dependent risk factor for the DTAst (OR: 6.0, IC 95 %: 2.6-13.7) and decrease the age of symptom onset (p < 0.005). They have also suggested that apo E genotyping may be of interest to perform differential diagnosis of neurodegenerative diseases in elderly subjects.