Studies of an abnormal serum albumin unstable upon storage.

A case of inherited bisalbuminemia was discovered in which electrophoretic controls showed that the proportion of the abnormal albumin decreased progressively during storage of the serum either at 4 degrees C or at room temperature. Such a decrease was also found when the serum was incubated with the proteolytic enzymes trypsin or plasmin. Studies with the isolated abnormal albumin showed that either during storage or after incubation with trypsin (or plasmin), its mobility became identical to that of normal serum albumin. Structural analyses showed that the albumin variant was identical to the previously described pro-albumin Christchurch that contains an additional N-terminal sequence: Arg-Gly-Val-Phe-Arg-Gln. It was therefore suggested that the progressive decrease of the abnormal albumin during storage by serum was related to the cleavage of the N-terminal abnormal sequence by plasmin already present in the serum. The decrease of the abnormal albumin during storage was inhibited by addition of cortisol to serum (1 mol per mol serum albumin). This was found related to a protective effect of cortisol bound to the albumin variant on proteolysis by plasmin.

[Serum bisalbuminemias: their clinical value]. / Les bisalbuminémies sériques: leur intérêt en clinique.

Bisalbuminemias are characterized on serum electrophoresis with a double band of albumin. They could be hereditary or acquired. This double band is composed of a protein with a normal mobility and with a protein with an other mobility which migrates in a more anodic or more cathodic position.

[Tricyclic antidepressants and therapeutic monitoring. An experience with trimipramine]. / Antidépresseurs tricycliques et monitorage thérapeutique. Une expérience avec la trimipramine.

Now it is not possible to choose an efficacious dosage of trimipramine when measuring serum drug concentrations. At once those measurement are useful to assure the long term surveillance of the treatment. That's why we propose to define a personal therapeutic interval that allows to limit the area in which the drug concentrations must be found.

[Comparison of three ratios of enzymatic activities measured in amniotic fluid to evaluate fetal lung maturity]. / Comparaisons de 3 rapports d'activités enzymatiques mesurées dans le liquide amniotique pour évaluer la maturité pulmonaire foetale.

Measurement of enzymatic activities in amniotic fluid could be helpful for the evaluation of foetal lung maturity. The ratio TLAP/GGT could be the most informative.

[Immunoelectrophoresis or immunofixation: identification of monoclonal gammopathy]. / Immunoélectrophorèse ou immunofixation: identification d'une gammapathie monoclonale.

Both methods enable the clinical laboratory to identify monoclonal gammapathies with a good sensitivity. The immunofixation method, more quickly used than the immunoelectrophoresis, is easier to obtain the best resolution. It is well adjust for the characterization of low concentration gammapathies like immunoglobulin light chains. Immunofixation appears to take a more and more important place in the clinical laboratory.