A domain of TEL conserved in a subset of ETS proteins defines a specific oligomerization interface essential to the mitogenic properties of the TEL-PDGFR beta oncoprotein.

TEL is a novel member of the ETS family of transcriptional regulators which is frequently involved in human leukemias as the result of specific chromosomal translocations. We show here by co-immunoprecipitation and GST chromatography analyses that TEL and TEL-derived fusion proteins form homotypic oligomers in vitro and in vivo. Deletion mutagenesis identifies the TEL oligomerization domain as a 65 amino acid region which is conserved in a subset of the ETS proteins including ETS-1, ETS-2, FLI-1, ERG-2 and GABP alpha in vertebrates and PNTP2, YAN and ELG in Drosophila. TEL-induced oligomerization is shown to be essential for the constitutive activation of the protein kinase activity and mitogenic properties of TEL-platelet derived growth factor receptor beta (PDGFR beta), a fusion oncoprotein characteristic of the leukemic cells of chronic myelomonocytic leukemia harboring a t(5;12) chromosomal translocation. Swapping experiments in which the TEL oligomerization domain was exchanged by the homologous domains of representative vertebrate ETS proteins including ETS-1, ERG-2 and GABP alpha show that oligomerization is a specific property of the TEL amino-terminal conserved domain. These results indicate that the amino-terminal domain conserved in a subset of the ETS proteins has evolved to generate a specialized protein-protein interaction interface which is likely to be an important determinant of their specificity as transcriptional regulators.

[Temporal muscle flap in cranio-facial reconstructive surgery. Apropos of 32 cases]. / Place du lambeau de muscle temporal en chirurgie réparatrice crânio-faciale. A propos de 32 cas.

The temporalis muscle flap is used in craniofacial reconstructive surgery to repair defects, to restore facial contours and to cover bone grafts. These possibilities of reconstruction are analysed in the light of 32 cases. After reviewing the anatomy and the surgical technique, this series is presented as a function of the various types of defect: cranio-orbital (9 cases), defects of the malar area (6 cases), maxillary defects (7 cases), mandibular defects (7 cases), malar and parotid soft tissues defects (2 cases), mastoid defects (1 case). This study indicates that the temporalis flap possesses several advantages: great vascular reliability, associated with simplicity of flap raising and an easily available tissue volume. The arc of rotation constitutes the limiting factor. Romberg's syndrome does not constitute an ideal indication of choice, as the muscle may be atrophied. Similarly, when the defect requires thin cover, it would be wiser to use a thinner flap, such as fascia temporalis superficialis. Donor site sequelae are negligible. Limitation of mouth opening (3 cases) and frontal paralysis (2 cases) are usually transient. The field of application of this flap can be extended by continuing the flap as far as the pericranium or calvarium, allowing complex reconstructions.

[Value of interstitial irradiation of keloid scars by Iridium 192. Apropos of 46 cases]. / Intérêt de l'irradiation interstitielle des cicatrices chéloïdes par Iridium 192. A propos de 46 cas.

The authors, after recalling the technique of Iridium 192* brachytherapy in the treatment of keloid scars, report a series of 46 cases operated at Rothschild Hospital (Department of Professor Baux) and irradiated at Tenon Hospital (Department of Professor Laugier), between 1981 and 1987. 87% of results were considered to be satisfactory.