[The C cell system and experimental thyroid apudomas in the rat: the combined action of 2-acetylaminofluorene and chlorpromazine in inducing systemic medullary type tumors. An ultrastructural study]. / Le système des cellules C et les apudomes expérimentaux de la thyroïde chez le Rat: actions combinées du 2-acétylaminofluorène et de la chlorpromazine permettant l'obtention systématique de tumeurs de type médullaire. Etude ultrastructurale.

Previous chronic administration of chlorpromazine (CPZ) before the start of the 2-acetylaminofluorene (2-AAF) action and during the cancerogenic process systematically facilitate the growth of apudome-like medullary tumors inside the thyroid gland. Ultrastructural studies of normal C cells, adenomatous C cells and cancerous C cells derivated from the normal cellular type show various specific transformations of few intracytoplasmic organelles. In the Golgi apparatus, the path of main maturation of calcitonin-like granules seems the same in the normal and in the adenomatous cells. On the contrary, the amount of calcitonin-like granules falls in the tumoral extensive tissue even though the golgian activity turns towards a high abnormal proliferation of clathrin vesicles or coated vesicles. This new fact is directly related with numerous extensions and repairs of much damage of the neoplastic cell membranes. Finally, the large medullary tumors (showing many atypic mitosis in glandular neoplastic C cell-type) are deeply penetrated by extensive and irregular vegetative nervous fibers.

[The endocrine pancreas in Varanus niloticus: ultrastructural and cytochemical electron microscopic study and X-ray microdiffraction]. / Le pancréas endocrine de Varanus niloticus: etude ultrastructurale et cytochimique en microscopie électronique et microdiffraction aux rayons X

Electron microscopy has confirmed that there are B and A1 insular cells in the Varanidae; nevertheless, the majority of cells are A2. It is the transformation of canalicular and acinar cells that is responsible for insular regeneration. Mixed cell type can be found very frequently. X Ray microdiffraction has shown that the beta granules contain high levels of zinc; similar concentrations are found in peri-insular exocrine cells. Seasonal sexual activity intensifies the process of exo-endocrine cellular transformation and increases both the zinc level in B and pre-B cells and the sulphur level in A2 cells.