ber Chromatin und DNS-Synthese im Nucleolus: Elektronenmikroskopische, autoradiographische und lichtmikroskopische Untersuchungen an Leberzellen von Ratten

Morphometric study of the interphase nucleus in some radiosensitive and radioresistant mammalian cells

The radiosensitive cell populations, such as resting lymphocytes from thymus, spleen, lymph node and blood, have much smaller nuclei (Vn (nuclear volume) approximately 20 to 70 microns3) compared to radioresistant G0 cells from non-lymphoid tissues (liver, kidney, brain, heart; Vn approximately 75 to 2700 microns3). It is suggested that radiation-induced disorganization of nuclear structures and cell pycnosis (interphase death) are promoted in G0 lymphocytes because in normal physiological conditions their nuclei assume a higher degree of chromatin condensation. In contrast, dispersion of chromatin into larger nuclear volumes, such as those of most non-lymphoid G0 cells, may hinder or delay radiation-induced cell death.

Fluorescence microscope and electron-microscope studies on the effect of trenimon on human tumour cells

A report is given on various forms of administration of Trenimon for local treatment of neoplasms of the serous membranes. For supervision and adjustment of the chemotherapeutic effect supravital staining with acridin orange and phase-contrast microscopy of the untreated effusion sediment are especially suitable. This facilitates distinction between newly formed and preformed granules, which is of importance for the diagnosis. Inhibition of dye-induced production of granules is a very sensitive criterium for assessment of cell vitality. The development of regressive changes in the tumour cells caused by chemotherapy is discussed with reference to micrographs of a metastatic pleural sarcomatosis. Electron-microscope studies on the exudate suggest that prior to necrobiosis an increased transfer of the granular nucleolar component into the cytoplasm takes place. This may be caused by a true increase in the transfer of nucleolar RNA towards the cytoplasm or by an inhibition in the late S-phase.