Human gastric choriocarcinoma serially transplanted in nude mice

A gastric choriocarcinoma cell line capable of producing human chorionic gonadotropin (HCG) was studied by sc transplantation and serial passages into nude mice fed under specific pathogen-free (SPF) conditions. The tumor-take rate at the serial heterotransplantation in SPF mice was high (greater than 95%), in contrast with a low rate in coventional animals (35%). The restoration of morphology and function of the original neoplasm were exclusively verified in SPF mice. Multiple lung metastases were found in 2 animals. The production, storage, and excretion of HCG by tumor cells were confirmed by its high content in serum and cystic fluid in tumors and by its intracellular localization. The tumor cells also contained a specific placental alkaline phosphatase in their membranes. The cells were various trophoblastic types ranging from primitive cytotrophoblasts to typical syncytial cells. The hormone effects of the tumor on sex organs of tumor-bearing animals were evident.

[Effects of hyper-and hypothyroidism on central nervous system with special reference to its effects on rectal temperature and brain norepinephrine levels in rats]

Infleunce of hyper-and hypothyroidism on amphetamine activity was observed by measuring the effects on hyperthermia and brain amphetamine and norepinephrine levels. Hyperthyroidism was obtained in rats injected with tri-iodothyronine 0.2 mg/kg i.p. every day for 5 days. Controls were treated with the vehicle 1.0 ml/kg i.p. for the same period. On the 6th day, d-amphetamine (10 mg/kg i.p.) was administered to the two groups of animals and the body temperature and brain amphetamine and norepinephrine contents were measured at 0 min, 15 min, 30 min and 60 min. Hyperthyroid rats showed a more marked hyperthermia than did the control animals. On the other hand "amphetamine-induced release of norepinephrine" of hyperthyroid rats was not so marked as in the control rats, however amphetamine levels did not differ in the two groups. Hypothyroidism was evident in the thyroidectomized rats. Controls for this group underwent a sham-operation. All animals were injected with amphetamine 21 days later. Amphetamine did not cause a hyperthermia in thyroidectomized rats. On the other hand, amphetamine levels were considerably higher than in the control rats, but the degree of norepinephrine release was comparable in the two groups.

Isolation and identification of prostaglandin E2 from gastrointestinal tract of shark Triakis scyllia

A prostaglandin was isolated from the gastrointestinal tract of the shark Triakis scyllia and identified as prostaglandin E2 by bioassay, thin-layer chromatography, gas-liquid chromatography, ultraviolet absorption spectrometry and mass spectrometry. The fatty acid composition of the tissue was also determined. The amount of eicosatetraenoic acid in this tissue was 17.2% of the total fatty acids, but the percentages of eicosatrienoic acid and eicospentaenoid acid were low.