Morphological and cytochemical characteristics of human cells transformed and made malignant by Rous and polyoma viruses]

In cells of human embryo skin--muscle tissue transformed by the Rouse sarcoma virus (23rd cell line) and polyoma virus (P-2 cell line), the mitotic activity was 48 0/00 for 23rd line, 51 0/00 for P-2 line as against 28 0/00 in the control cells. The transformed cells possessed greater amounts of RNA and DNA and protein--bound SH-groups, different forms of glycogen deposits, as well as higher acid phosphatase enzyme activities; there was practically no difference in acid mucopolysaccharide content or NAD-H2-diaphorase and succinate dehydrogenase activities.     

The role of Ca ions in restoration of the structure of interphase and mitotic chromosomes in PK living cells after hypotonic stress.

The dynamics of mitotic chromosome and interphase chromatin recondensation in living PK cells during their adaptation to hypotonic medium was studied. The recondensation process was found to be slowed down by the modification of plasma membrane with low concentrations of glutaraldehyde, while osmotic reactions of glutaraldehyde-treated cells remain unchanged. The effect of glutaraldehyde can be rapidly reversed by the addition of Ca(2+)-ionophore A23187. Intracellular Ca(2+)measurements show that the adaptation to hypotonic shock is accompanied by restoration of free Ca concentration, whereas the delay of chromatin condensation in glutaraldehyde-treated cells is paralleled by the decrease of Ca level. The mechanisms implying the role of low concentration of Ca(2+)in chromatin compactization in vivo are discussed.     

Capacity of fusicoccin for inducing the production of early interferon

The response of human and animal cells to the action of fusicoccyne (FC), a fungal metabolite with phytohormonal properties, was evaluated. As shown by in vitro studies, FC had the capacity to induce the production of early interferon (IFN) in the blood serum of non-inbred white mice and to enhance the natural cytotoxic activity of human lymphocytes. In vitro experiments also revealed that the action of FC inhibited the metabolism of actively proliferating monocytic leukemia cells J-96 and human ovarian carcinoma cells CaOv, as well as mouse fibroblasts L-929. The common character of the mechanism of action of FC and IFN, having well-known antiproliferative and immunomodulating activity, is discussed.     

The capacity of fusicoccin for inducing the synthesis of early interferon

The response of human and animal cells to the action of fusicoccin (FC), a fungal metabolite with phytohormonal properties, was evaluated. The capacity of FC for inducing the synthesis of early interferon (IFN), supplied into the blood serum of common white mice, and for enhancing the natural cytotoxic activity of human lymphocytes in vitro was established. The metabolism of actively proliferating monocytic leukemia cells J-96 and human ovarian carcinoma cells CaOv, as well as mouse fibroblasts L-929, was found to be inhibited under the in vitro action of FC. The common character of the mechanisms of action of FC and IFN having antiproliferative and immunomodulating activity is discussed.     

Coupling membranes as energy-transmitting cables. I. Filamentous mitochondria in fibroblasts and mitochondrial clusters in cardiomyocytes

An hypothesis considering mitochondria as intracellular power-transmitting protonic cables was tested in human fibroblasts where mitochondria are thin and long and in rat cardiomyocytes where they show cluster organization. Mitochondria in the cell were specifically stained with fluorescent-penetrating cation ethylrhodamine, which electrophoretically accumulates in the mitochondrial matrix. A 40-micron-long mitochondrial filament of fibroblast was illuminated by a very narrow (less than or equal to 0.5 micron) laser beam to induce local damage of the mitochondrial membranes. Such a treatment was found to induce quenching of the ethylrhodamine fluorescence in the entire filament. According to the electron microscope examination, the laser-treated filament retained its continuity after the laser illumination. Other mitochondrial filaments (some of which were localized at a distance less than 10 micron from the laser-treated one) remained fluorescent. In a cell where mitochondrial filaments seemed to be united in a network, laser illumination of one filament resulted in fluorescence quenching in the whole network, whereas fluorescence of small mitochondria not connected with the network was unaffected. The illumination of cardiomyocyte was found to result in the fluorescence quenching not only in a laser-illuminated mitochondrion but also in a large cluster of organelles composed of many mitochondria. Electron microscopy showed that all the mitochondria in the cluster change from the orthodox to the condensed state. It was also found that mitochondria in the cluster are connected to one another with specific junctions. If a mitochondrion did not form junctions with a quenched cluster, its fluorescence was not decreased even when this mitochondrion was localized close to an illuminated one. The size of the mitochondrial cluster may be as long as 50 micron. The cluster is formed by branched chains of contacting mitochondria, which may be defined as Streptio mitochondriale. In the cardiomyocyte there are several mitochondrial clusters or, alternatively, the quenched cluster is a result of decomposition of a supercluster uniting all the mitochondria of the cell. Cluster organization of mitochondria could also be revealed when a single mitochondrion was punctured in situ with a microcapillary. The obtained data are in agreement with the idea that mitochondrial junctions are H+ permeable so that, within the cluster, delta psi may be transmitted from one mitochondrion to another. The above results are consistent with the assumption that mitochondrial filaments or networks represent a united electrical system.(ABSTRACT TRUNCATED AT 400 WORDS)     

Interaction of vertebrate viruses and insect nuclear polyhedrosis viruses with transplantable diploid embryonal drosophila cells

When the Drosophila cells were infected with the mixo- and arboviruses, in case of influenza A/WSN virus a rise in the titre and slight cytopathogenic effect with the subsequent decrease in the titre was observed. Since the decrease in the virus titer was not observed when actinomycin D was added, it was supposed that interferonlike inhibitor may be produced by the infected cells. Vacuolization and increase in the size of the infected cells were caused by all the nuclear polyhedrosis viruses tested. The number of the infected cells depended on the virus type and multiplicity of the infection.     

Activity of human natural killer cells against target cells possessing different sensitivity to interferon]

The cytotoxic activity of peripheral blood natural killers (NK) against target cells (TC) J-96 and L-929 with high sensitivity to interferon (IFN) action, J-41 and MCB resistant to IFN action and line K-562 labelled by H3-uridine was studied in 14 hrs cytotoxic test. It has been shown that human TC J-96 didn't differ from the J-41 in their sensitivity to NK cytotoxicity and they are strongly resistant to NK than TC K-562. The murine TC L-929 as the human TC didn't differ from the MCB in their sensitivity to NK lysis and had also the same sensitivity to NK as the K-562 cells.