The combination of 1-methyl-1-nitrosourea (MNU) and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) has an overadditive toxicity in rats. This overadditive effect is dependent on drug sequence and time interval between the administration of both compounds. Application of MNU within 2 h prior to BCNU or simultaneous application of both compounds displayed the highest toxicity. The dose-limiting toxicity appears to be a severe damage of the intestinal mucosa.

Animals↗

PubMedDate not supplied

Deregulated c-fos expression interferes with normal bone development in transgenic mice.

Transgenic mice were generated expressing c-fos genes under the control of the human metallothionein promoter. Although high levels of c-fos messenger RNA were detectable in a variety of tissues, deregulated c-fos expression specifically interfered with normal bone development without inducing malignant tumours.

Animals↗

PubMedDate not supplied

[Cumulation of strontium-85 in various types of bone neoplasms].

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Bone Neoplasms↗

PubMedDate not supplied

Evaluation of nuclear morphology in adriamycin sensitive and resistant cells.

The adriamycin sensitive and resistant human breast cancer cells (MCF-7) were investigated by computerized image analysis for establishment of characteristic cell nuclei-morphological differences. Using specially developed algorithms and a large set of subvisual parameters, morphological features characteristic for the resistant cell line were described. The most useful parameters for distinguishing the resistant from sensitive cells are related to chromatin structure and include integral optical density per micron 2, the average area of chromatin region, and the integral density of the chromatin region per micron 2. Besides the size of the nuclei, the two features with the most discriminatory power belonged to those characterizing patterns of chromatin condensation. The results of quantitative analysis suggest that drug resistance relates to specific chromatin patterns. Compared to sensitive cell line, the resistant MCF-7 cells show distinguished coarse chromatin pattern with enlarged condensed chromatin regions.

Algorithms↗

PubMedDate not supplied

Morphologic characteristics of the interaction between normal cytotrophoblasts and their malignant counterpart in the development of trophoblastic neoplasia.

OBJECTIVES: To define the biology of the tumor-host cell interaction with regard to cellular kinetics and morphologic changes during cell-cell interaction in an in vitro model of trophoblastic neoplasia. METHODS: Using a coculture in vitro system of cytotrophoblasts and choriocarcinoma cells, we investigated the cellular kinetics and the morphologic changes in these interacting cells. A fully automatic time-lapse image system was used to record phase contrast images of the cocultured cells in a tissue culture chamber. To examine cytoskeletal structure, immunofluorescent-labeled antibodies against intermediate filaments were used. Slides were examined with a confocal laser scanning microscope and subjected to computed analysis. RESULTS: The choriocarcinoma cells attract normal cytotrophoblasts using what resembles pseudopodia to engulf the latter cells and thus form slow-growing colonies. In this process, new hybrid cells are formed, which can be differentiated from their original contributors by morphologic characteristics. CONCLUSION: This phenomenon supports our previous biochemical and molecular data on the role of cell-cell interaction in the complex process of cytotrophoblast transformation and the development of gestational trophoblastic neoplasia.

Cell Communication↗