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To test the relationship between tumor malignancy and content and distribution of polyamines and nucleic acids, 2 forms of human gestational trophoblastic tumors were examined: the hydatidiform mole (self-limited form) and the human choriocarcinoma (invasive form) xenografted into nude mice. The results indicate that there are 2 significant differences between the choriocarcinoma and the mole: 1) the choriocarcinoma is characterized by increased polyamine and nucleic acid levels, 2) the 2 tissues differ in their putrescine:spermidine and spermidine:spermine ratios. There is an increase in polyamines in the urine of mole-bearing patients over that of normal controls. The correlation between putrescine and spermidine with the chorionic gonadotropin indicates that these 2 polyamines reflect the biological activity of the mole.

The effects of ionizing radiations on valyl-tRNA synthetase (L-valine tRNA ligase (AMP), E.C.6.1.1.9.), 100-fold purified from rat liver and Morris hepatoma 7777, are reported. The results showed that: 1) the enzymatic activity is strongly inhibited by radiations; 2) the enzymatic inactivation is much more marked in dilute than in concentrated solutions; 3) the inactivation of enzyme is linked to oxidation of sulphydryl groups indispensable to the catalytic activity of the enzyme; 4) no substantial difference in relation to inactivation by radiation was observed, between rat liver and Morris hepatoma 7777 enzymes.

The H1 fraction in Oberling Guerin-Guerin's myeloma was isolated, and an electrophoretic study was carried out in order to establish its composition. The results obtained show that the H1 fraction is heterogeneous and is formed of 2 sub-fractions. These were separated by preparative gel electrophoresis. They differ in molecular weight, electrophoretic mobility, and primary structure. Each sub-fraction exists in 2 different electric states.

Polyamine and nucleic acid levels were determined in normal human breasts, in primary infiltrating ductal carcinoma breasts, in the uninvolved tissues of the same carcinoma-bearing breasts and in the urine of the same patients. The results showed that the production of polyamines in the carcinoma tissue is significantly higher than in normal tissue; the presence of a carcinoma in the breast does not modify the levels of polyamines and nucleic acids in the surrounding uninvolved tissue; spermidine and spermine are correlated both with DNA and RNA in the carcinoma; the urinary polyamine levels in the carcinoma-bearing patients were not significantly different from that of controls. There appeared to be a close relationship between polyamine biosynthesis and tumoral mammary cell development and a very fine control between the biosynthesis of both spermidine and spermine and nucleic acids. In addition, the localized solid breast carcinoma, with non-proven metastases, did not provoke an increase in polyamine excretion.

Urinary polyamine levels were determined in patients with acute leukemia, before and during chemotherapy, in order to confirm whether tumor cell death, due to successful chemotherapy, increases the release in urine and serum of polyamines from tumor tissues (12). Comparison between the polyamine test and cytological data indicated that a rise in urinary spermidine levels occurs during the first 3 days of therapy, both in the responsive and unresponsive patients. However, in the responsive patients the spermidine increase was higher (at 5 % significant level) than in the unresponsive ones, and it was coincident with the fall of the blast cells and the revival of normal hematopoiesis. Increases in putrescine levels were also observed, but there were no significant differences (5 % level) between the 2 groups of patients. When polyamine determinations were carried out following chemotherapy cycles, the relapse of the disease was always accompanied by an increase in putrescine.

The content of DNA and oestradiol receptors was measured in two different samples taken from the same tumoral mass of 33 primary infiltrating ductal carcinomas. The results were related to the total cytoplasmic protein and to the DNA of the tissue. The results showed that variations of both DNA and oestradiol receptors are frequent and often significant. The reliability of analyses carried out on a single biopsy is discussed.