[A teleradiotherapeutic network for lymphoma patients within the competence network malignant lymphomas]. / Aufbau eines teleradiotherapeutischen Netzwerks für Lymphompatienten im Rahmen des Kompetenznetzes Maligne Lymphome.

PURPOSE: The aim of the subproject "Radiotherapy" within the competence network malignant lymphoma, funded by the Federal German Ministry of Education and Research (BMBF), was to build-up an electronic imaging transfer between five University departments of Radiation Oncology to improve communication between study centers and reference centers. MATERIALS AND METHODS: We describe our experiences with these modern teleradiotherapeutic possibilities, its feasibility within mutticentric clinical trials. RESULTS: Telemedical functions could successfully be integrated into the existing quality asssurance programs of radiotherapy. Since January 2001 more than 700 patients (trials HD10-HD15 of the German Hodgkin Study Group, GHSG) could be assessed after digital transfer via internet, on mobile data carriers or an ISDN-connection in the radiotherapy reference center Cologne. Transfer of digital imaging between participating study centers and the radiotherapy reference center allows immediate or a short-term evaluation of adequacy of treatment fields by expert radiation oncologists before the start of radiotherapy. This improves dialogue and consensus between radiotherapy reference centers and study centers and thus contributes towards high radiotherapy quality for lymphoma patients. CONCLUSION: The long-term aim is to network all those hospitals, institutions and private facilities taking part in the GHSG trials to achieve an integrated system of cooperation. This improves dialogue and consensus between the radiotherapy reference center and the study centers and thus contributes towards high radiotherapy quality for patients with Hodgkin's lymphoma.

Modulatory actions of the new antiprogestins ZK 98.299 and ZK 98.734 and of RU 486 on luteinizing hormone secretion and progesterone effects in pituitary gonadotrophs.

The effects of the antiprogestins (APs) ZK 98.299, ZK 98.734 and RU 486 on GnRH-stimulated LH secretion and their antagonistic activity on progesterone (P) actions were investigated in cultured pituitary cells from adult female Wistar rats. P (100 nM) was able to exert a facilitatory effect on GnRH (1 nM)-induced LH secretion after short-term (4 h) treatment of estradiol-primed (1 nM, 48 h) rat pituitary cells. When the APs (10 pM-10 microM) were introduced during the 4 h incubation period with P the facilitatory effect of P was totally abolished at concentrations greater than 10 nM (ZK 98.299, ZK 98.734) and greater than 1 nM (RU 486). Also the APs were shown to block the inhibitory action of P which occurs after long-term incubation of pituitary cells with this steroid. However at concentrations greater than 10 nM (ZK 98.734, RU 486) and greater than 100 nM (ZK 98.299) this antagonistic action of the APs was lost. To evaluate whether the APs have direct effects on GnRH-induced LH secretion in the absence of exogenous P pituitary cells cultivated for 48 h with or without 1 nM estradiol were incubated for 4 or 24 h with increasing concentrations of the APs (10 pM-10 microM). Four hour treatment of non-estradiol-primed cells with ZK 98.299 or ZK 98.734 was without any effect on the LH response to a 1 nM GnRH-stimulus. Only the highest concentration of RU 486 (10 microM) reduced the LH response. Twenty-four hour treatment of the cultures with the APs led to enhancement of GnRH-stimulated LH secretion by up to 113, 37 and 33% for ZK 98.734, ZK 98.299 and RU 486, respectively. When estradiol-primed cells were used for the same experiments we observed exclusively inhibitory effects on GnRH-induced LH secretion after 4 and 24 h treatment periods. It is concluded that these new APs are potent inhibitors of P-actions, but also per se they induce diverse effects on GnRH-stimulated LH secretion in cultured rat pituitary cells which have to be taken into account.