Biochemical characterization and analysis of the transforming potential of the FLT3/FLK2 receptor tyrosine kinase.

We recently cloned an additional member of the receptor type tyrosine kinase class III. This new gene, called Flt3 by our group [Rosnet, O., Matteï, M.

Coexpression of the genes for interleukin 6 and its receptor without apparent involvement in the proliferation of acute myeloid leukemia cells.

Leukemic cells isolated from patients with either acute myeloid leukemia (AML) or acute lymphoid leukemia (ALL) were screened for their capacity to express the interleukin 6 (IL-6) and IL-6 receptor genes, both at the RNA and protein levels. Variable levels (10 to greater than 600 U/ml) of an IL-6 activity, inhibited by neutralizing anti-IL-6 antibodies, were detected in AML cell supernatants using the B9 cell bioassay. High levels (greater than 100 U/ml) were observed in differentiated (M4 and M5 stages) AML, as well as in less mature (M1 and M2 stages) AML.

Screening of HBsAg and post-transfusional hepatitis type B.

The Authors consider the different opinions expressed about the HBsAg screening in blood donors and its usefulness in preventing post transfusional hepatitis B (PTHB). They report data on the incidence of such a disease, as observed in their transfusional experience during the last 5 years, with a comparison between results obtained after CEP and RIA screening systems. The Authors point out the results of their retrospective investigation: the transfusion blood with a low HBsAg titre showed to be more infectious than the blood with high titre.

[New method for demonstrating HBs antigen saturated by its antibodies].

The modalities for the carrying out of a technique for the detection of HBs antigen, even when it is completely saturated by the relevant antibodies, and its results are set out. The technique includes the preliminary acidification of the test serum at pH 2.4, in such a way as to detach the antibody from the antigen, subsequently, the effect of the hearing (70 degrees C) for some minutes to destroy the antibody.

[Research on Au antigen by radioimmunologic method: retrospective study on 2491 transfusions].

The AA. have researched Au antigen by solid phase radioimmunoassay technique (RIA) in 2491 sera kept in freezer and relative to as many transfusions made in the 7 previous months and already selected for Au antigen by electrosyneresis. In base of the retrospective analysis, the AA.