Chemotherapy of yolk sac tumor heterotransplanted to nude mice was studied. 1. Yolk sac tumor of the ovary taken from a 38-year -old woman was transplanted to BALB/c female nude mice. The transplantable tumor cells produce a solid tumor, designated as YST-1 tumor. The YST-1 tumor cells preserve the histological appearance of a human yolk sac tumor and produce x-fetoprotein. The tumors on passage 8 were used for experimental chemotherapy. 2. Anticancer drugs clinically known to be effective for ovarian cancer, such as Adriamycin, Carbazilquinone, 5-Fluorouracil, Cyclophosphamide, Mitomycin C, Chromomycin A3, Vinblastine and Bleomycin were administered intraperitoneally to tumor-bearing nude mice. Tumor size was measured two or three times a week during the course of experiments. Therapeutic effects were evaluated by tumor size and relative tumor size before and after experiments. Among these drugs, Vinblastine and Bleomycin combination showed the significant effect arresting the growth of YST-1 tumor.

Aclacinomycin A, a new anthracycline antitumor antibiotic, was given to rabbits by single instillation or single intracutaneous injection and to guinea pigs by single subcutaneous or intramuscular injection to examine the irritative effect. Slight dilatation of blood vessel and swelling in the conjunctiva and nictitating membrane were observed in the eyes of rabbits given 1% solution. Edema in the bulbar conjunctiva, iris and cornea was histologically noted. Washing of the eyes after drug instillation prevented these damages. Subcutaneous and intracutaneous injections of 1% solution (0.2 ml) gave hyperemia, swelling and necrosis at injection site. Cellular infiltration, fibrosis and necrosis were histologically detected. Intramuscular injection of 1% solution (0.2 ml) also provided induration and swelling at injection site. Histologically cellular infiltration and necrosis were observed. These irritative effects were much slighter in administration of 0.1% solution. No change was observed with 0.01% solution.

Japan White rabbits were treated with aclacinomycin A, a new anthracycline antitumor antibiotic, at a dose of 6.25 or 25.0 mg/kg by single intravenous, or 12.5 or 50.0 mg/kg by single oral administration, respectively. Beagle dogs were treated at a dose of 3.0 or 6.0 mg/kg by single intravenous injection. In rabbits in higher dose groups, RBC and WBC counts as well as lymphocyte ratio in peripheral blood decreased on day 1. Nucleated cell counts and erythroid elements in bone marrow decreased to raise M/E ratio (Myeloid/Erythroid ratio) on day 3. In a dog given at 6.0 mg/kg, WBC and platelet counts, lymphocyte and neutrocyte per cents in peripheral blood and also nucleated cells, particularly erythroid elements in bone marrow remarkably decreased on day 3 accompanied with an increase in M/E ratio. These changes were almost completely recovered by day 14 in both animals. No abnormalities were found in lower dose groups. Male Wistar rats, treated with the drug at a dose of 1.5 mg/kg by daily intraperitoneal injection for 30 days, showed slight decreases in peripheral WBC and RBC counts and M/E ratio in bone marrow. No change was observed in rats treated at 0.75 mg/kg and less for 30 days.