A human gastric choriocarcinoma cell line with human chorionic gonadotropin and placental alkaline phosphatase production

A gastric choriocarcinoma cell line synthesizing human chorionic gonadotropin (HCG) was established in 1971 by Oboshi et al. and was found to possess human placental alkaline phosphatase. The present paper also deals with the relationship between the cell growth and HCG secretion and with cellular localization of HCG and human placental alkaline phosphatase by cytochemical and ultrastructural methods. This cell line was found to secrete HCG during cellular proliferation, with the maximum secretion in the stationary phase (about 1 muIU/cell/48 hr), and the hormone could be detected in a small proportion of mono- and/or multinuclear cells in both logarithmic and stationary phases. The organ-specific, heat-stable, L-phenylalanine-sensitive, immunoreactive human placental alkaline phosphatase was localized on the cell membrane of many cells. Ultrastructurally, the line consisted mainly of cytotrophoblastic and intermediate cells in the process of syncytial formation, with more or less squamous metaplasia. From these findings it was concluded that the cell line maintained the properties of trophoblastic cells from morphological and functional aspects, i.e., it was a cell line with two distinct marker substances.

Histopathological study of six cases of Castleman's tumor

A histopathological analysis of six cases of Castleman's tumor by means of light and electron microscope was performed, with a review of literature. All cases were hyaline-vascular type as described by Keller et al. The morphology of lymphnoid follicles in the lesions varied according to the presence or non-presence of the germinal center which was from large active to amaciated hyalinized. The lymphnoid follicle was essentially similar to that of normal lymph node undergoing some reactive process. Depending on the observation of serial sections, the lesions had lymphatic sinuses around the blood vessels in the tumor parenchyma, some of which were proved to be connected to the abortive marginal sinuses. These findings and some clinical records suggest that the lesion originates from the lymph node and is a result of its reactive hyperplasia.

The effects of gelatin on aggregation of protoplasts from higher plants

Aggregation of protoplasts of Allium fistulosum L., Brassica chinensis L. and Daucus carota L. was induced in great frequency with gelatin and early products of gelatin degradation. The optimal gelatin concentration was 2-5%. The aggregated protoplasts fused into groups and cell walls were formed around them in culture.

Embryoids derived from isolated protoplasts of carrot

Protoplasts isolated enzymatically from carrot root tissues developed into cell clusters in a liquid medium containing coconut milk and naphthaleneacetic acid (NAA) or 2,4-dichlorophenoxyacetic acid (2,4-D). Cells of the resulting calluses differentiated into embryoids on an agar medium containing coconut milk or kinetin.