Le cancer de la prostate: Acquis et challenges pour l'an 2000

Principles of the diagnosis and treatment of prostate cancer at any stage are still improving. Early diagnosis is accessible throughout the use of the PSA test associated with digital rectal examination which lead to indicate transrectal biopsies. This allowed to treat patients at an earlier stage and significantly improved prognosis in the case of organ confined disease. Progress made in the radical prostatectomy technique have contributed to decrease the postoperative morbidity and is the treatment of reference in clinically localized disease. Radiation therapy still remains a valuable alternative, however, results are more difficult to evaluate. Hormonal treatment using androgen deprivation is indicated at the stage of metastasis. LHRH agonist associated with anti antiandrogens are as much efficacious as surgical castration. Unfortunately, the prognosis of advanced disease remains unpredictable. Objectives for the future will be to improve the diagnostic and staging of prostate cancer et to better define therapeutic indications; better understand the effects of androgen deprivation; and to propose new therapies for hormone refractory cancers.     

Le changement de sexe et la sexualisation cytoplasmique

Sans résumé     

Nouvelle nomenclature lithostratigraphique « événementielle » pour le Jurassique de la Tunisie atlasique

The various and heterogeneous nomenclatures previously proposed for the Jurassic of both central and northern Tunisia were examined and revised. In this work we propose a new lithostratigraphic chart taking into account the progress of our knowledge on the sedimentological and palaeontological (ammonites) aspects obtained during the two late decades. This chart summarizes and restores the major sedimentary and stratigraphic events (discontinuities) recorded in the Jurassic rocks. It outlines the main phases of the palaeogeographic evolution of the Tunisian atlasic domain during the Jurassic, in relation with the main controlling factor (tectonic and eustatism), which accompanied the tethyan rifting.     

Modulation de la Réponse du Xyléme selon la Nature de l'Agression Vasculaire

Modulation of the xylem response to different types of vascular aggressions The evolution of cells lining the vessels in the stem xylem of carnation was compared in sham-stressed (s. e.), V. dabliae-infected (i V. d.) and P. cinerescens-infected (i P. c.) plants. All experimental stresses triggered ultrastructural changes leading to the appearance of new cell types. In parallel, vacuolar polyphenols were metabolized and dense-core vesicles appeared. These were early and independant phenomena. In all cases the reactions of carnation xylem were stronger against Verticillium than against Phialophora. Differences in vascular gummosis were disclosed whatever the criterion used (speed of installation, relative importance of the phenomenon, level of structural complexity, dynamics of appearance of the different structures). The possible relations between cell structures and gummous secretions were investigated by means of comparison of an efficient defence system (i V. d.) with a deficient one (i P. c.). All the criteria selected for analysis confirm that faced with a specific parasite the host response was disrupted. In other words, the biosynthetic pathways normally used by the plant after a fungal aggression were blocked, slowed or diverted. The differences in the responses of carnation to Verticillium and Phialophora give a picture of parasite specificity in agreement with the model recently proposed by de Wit (1981) for tomato/Cladosporium fulvum.     

Le Cortex de la Vacuole Contractile et son Ultrastructure chez les Ciliés

SYNOPSIS. In various ciliates the contractile vacuole is a permanent organelle, delimited by a differentiated cortex.
The cortex is made up of a dense reticulum of anastomosing tubules limited by a smooth membrane, and vesicles. This "spongiome" can be considered as a localized and specialized condensation of the endoplasmic reticulum.     

Métastase rénale d’un carcinome vésiculaire de la thyroïde révélée par le balayage du corps entier à l’iode 131

Distant metastasis of differentiated thyroid carcinoma generally affect lung and/or bone tissue. Renal metastasis from thyroid carcinoma is extremely rare. We report a case of renal metastasis from a follicular thyroid carcinoma in a 55-year-old man, occuring 11 years after total thyroidectomy, fortuitously discovered on a whole body scan carried out after 131-iodine therapy for neck recurrence of disease. Salient features of our clinical case are the fortuitous mode of discovery the unilateral localization of metastases and especially the long time interval which separates its detection from that of the primitive tumour. This case report exemplifies the useful role of the whole body scan carried out after 131-iodine therapy better adapted to reveal often undetectable occult metastases with low dose, but also to ensure a regular and protracted follow-up of patients treated for differentiated thyroid carcinoma.