Christiane Rimbaut

Translocation involving chromosome 22 in Ewing's Sarcoma. A cytogenetic study of four fresh tumors

Ewings sarcoma was described in 1921 by James Ewing as a diffuse endothelioma of bone and, for some time, was believed to be an undifferentiated type of Parkers sarcoma. At present, these two entities are thought to be distinct, the macroscopic and microscopic aspects of Ewings sarcoma being very characteristic, although the exact cell type of this tumor remains unknown. This has lead many workers to study this sarcoma in order to recognize its origin. We thought it of interest to carry out cytogenetic investigations of our cases of Ewings sarcoma, since very few chromosomal data on this malignancy exist in the literature [1-3].

Molecular duality of DNA ligase in axolotl corresponds to distinctive transcriptional information

Based upon the use of specific antibodies and sucrose gradient sedimentation analysis, the present work describes the use of the post-transcriptional equipment of the urodele egg to compare the information contained in two RNA samples extracted from respectively liver and activated axolotl eggs. It is shown that besides the normal DNA ligase activity present in the host Pleurodeles eggs, RNA can translate for the specific carried information revealing a difference between the two samples. Moreover, unlike in nuclear transplantation, the homologous DNA ligases are not mutually exclusive. These observations give a new convincing support of the genetic basis of the molecular duality of DNA ligases.

Localization immunohistochimique de la gonadothrophine chorionique et de l'alpha-foetoprotéine dans les polyembryomes: Description et interprétation

Summary As polyembryomas are special forms of human teratomas in which numerous structures mimicking the early stages of the human embryo are conspicuous, immunoperoxidase staining of these embryoid bodies (EB) has been used to reveal the initial appearance and localization of βHCG and AFP, respectively, in amnion and in primary yolk-sac. EB are involved in the building of various questionable patterns of teratomatous germ-cell tumours. Special emphasis has been placed on tracking yolk-sac tumour patterns through dislocating EB, using a specific anti-human AFP serum.

Une technique immunologique (immunoperoxydase ABC) permet de déceler une différenciation hépatique dans les tératocarcinomes de la souris

Summary The present work shows that hepatic tissue occasionally appears in certain mouse teratocarcinomas: the presence of hepatic structures in these tumours, suspected on the basis of routine histological examination, is confirmed here by the use of anti-mouse alpha-fœtoprotein serum and the ABC immunoperoxidase technique.

Le marquage immunologiquede l'α-ftoprotéine dans l'endoderme proximal et sa signification dans les différenciations extra-embryonnaires des tératocarcinomes de la souris

Summary The ABC technique using a specific anti-mouse α-fœtoprotein (AFP)serum permits identification of groups of extraembryonic proximal endoderm cells in certain teratocarcinomas. These AFP + cells are always associated with trophoblastic and parietal endodermal patterns and structures. These observations strongly support the hypothesis of a common precursor to the extraembryonic tissues which appears during the first phases of egg development.