[Ureteral obstruction caused by retroperitoneal metastasis of gastric carcinoma]. / Obstruction urétérale par métastases rétropéritonéales du carcinome gastrique.

Nine patients with ureteric obstruction caused by retroperitoneal metastasis of gastric tumor have been observed in our clinic during the last five years. In all cases flank pain and the dilatation of the renal collecting system were the first signs of the disease. Despite the urological and radiological examinations in 3 cases the exact cause of the occlusion could be established only by autopsy. Most of the carcinomas showed the same histological type and were advanced tumors at the time of diagnosis. This kind of aggressive tumor carries a very poor prognosis, palliative nephrostomy has been performed.

Factors involved in the plasminogen activation system in human breast tumours.

The plasminogen activation system is a delicately balanced assembly of enzymes which seems to have primary influence on tumour progression. The conversion of plasminogen into serine protease plasmin with fibrinolytic activity depends on the actual balance between plasminogen activators (urokinase type; u-PA and tissue type; t-PA) and their inhibitors (type 1 and 2 plasminogen activator inhibitors; PAI-1 and PAI-2). The purpose of this study was to determine the exact histological localization of all the major factors involved in plasminogen activation, and activation inhibition (plasmin system) in benign and malignant breast tumour samples. Our results show that factors of the plasmin system are present both in benign and malignant tumours. Cancer cells strongly labelled for both u-PA and t-PA, but epithelial cells of fibroadenoma samples were also stained for plasminogen activators at least as intensively as tumour cells in cancerous tissues. In fibroadenomas, all the epithelial cells were labelled for PAI-1. Staining became sporadic in malignant tumours, cells located at the periphery of tumour cell clusters regularly did not show reaction for PAI-1. In the benign tumour samples the perialveolar connective tissue stroma contained a lot of PAI-1 positive cells, showing characteristics of fibroblasts; but their number was strongly decreased in the stroma of malignant tumours. These findings indicate that the higher level of u-PA antigen, detected in malignant breast tumour samples by biochemical techniques, does not necessarily indicate increased u-PA production by tumour cells but it might be owing to the increased number of cells producing u-PA as well.(ABSTRACT TRUNCATED AT 250 WORDS)