BACKGROUND There is a therapeutic dilemma for the pregnant patient with malignancy requiring chemotherapy. CASE We had a case of a 30-year-old pregnant woman with a yolk sac tumor who underwent right salpingo-oophorectomy at 22 weeks gestation. Chemotherapy during pregnancy was postponed because of concern with the risks of the chemotherapy to the fetus. After the operation, L2 fraction of al...

Rat embryos, explanted with their embryonic membranes during the early stages of organogenesis (H-l (H days gestation), were grown in culture in roller tubes. Yolk-sac antibody (sheep anti rat yolk-sac gamma globulin), known to be teratogenic when injected into pregnant rats, was added to the culture medium. At concentrations of 01 mg/ml or more the antibody caused gross retardation of growth a...

The amniote egg was a key innovation in vertebrate evolution because it supports an independent existence in terrestrial environments. The egg is provisioned with yolk, and development depends on the yolk sac for the mobilization of nutrients. We have examined the yolk sac of the corn snake Pantherophis guttatus by the dissection of living eggs. In contrast to the familiar fluid-filled sac of b...

In this study, we present statistical analyses of pineal tumors based on the data from Brain Tumor Registry of Japan. The most frequent tumor in the pineal region was germinoma, and it accounted for 49.2% of all pineal tumors; it was followed by pineocytoma (8.5%), glioma (6.5%), pineoblastoma (5.1%), malignant teratoma (5.2%) and teratoma (5.1%). Germinoma is most frequent among patients betwe...

To examine the functional differentiation of chloride cells in the yolk-sac membrane of tilapia (Oreochromis mossambicus) embryos, we developed a 'yolk-ball' incubation system in which the yolk sac was separated from the embryonic body and subjected to incubation in vitro. The yolk-ball preparation consists of the yolk and the covering yolk-sac membrane, which contains a rich population of chlo...

Mutant mice deficient in glucose-6-phosphate dehydrogenase were used to induce teratomas. This enzyme is linked to the X chromosome, which can be inactivated in female embryo. The differences in the enzyme activity between yolk sac mesoderm and embryo versus yolk sac endoderm can be detected in female concepti by using appropriate crosses of wild-type and G6PD-deficient mice. Histochemical stud...