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A review of the metabolic pathways and interaction with DNA of benzo[a]pyrene and some other carcinogens is presented. Consideration is given to the formation and persistence of adducts in relation to carcinogenic process.

The influence of folate and antifolate on the cytostatic activity of fluoropyrimidines has been examined extensively. From all of present work, it is apparent that methotrexate can be synergistic or antagonistic in its interaction with 5-fluorouracil, depending on the sequence used and the metabolic machinery present in the target cell. The interaction between commonly administered 5-fluorouracil and leucovorin may enhance carcinostatic efficacy of 5-fluorouracil in patients with colon carcinoma.

This article contains a survey of works, published in the last few years on plasminogen activators inhibitors in neoplastic tissues. These inhibitors belong to a heterogenous group of proteins, having different molecular weights and specific ways of acting. They exemplify immunological relationship to known inhibitors of fibrinolysis from normal tissues--i.e. the inhibitors from endothelial cells--(PAI-1) and placental inhibitor--(PAI-2). To PAI-1 type belong: acid-stabile inhibitor of fibrinolysis with Mr 50,000 from HTC hepatoma cells in rats, acid-labile inhibitor Mr 42,770 produced by HepG2 human hepatoma cells; the inhibitor with Mr 54,000 from HT 1080 human cells from fibrosarcoma and single-chain acid-stabile inhibitor with Mr 50,000 from MJZJ melanoma cells. In PAI-2 type we can mention the inhibitor with Mr 47,000 from U-937 histiocytic lymphoma cells.