Reactivity of HeLa tumoral cells under the in vitro action of some aromatic compounds from the phytomass.

The in vitro action of some natural polyphenolic preparations, extracted from the leaves of Asclepias syriaca, upon the proteinosynthesis of HeLa cancerous cells and, implicitly, upon the development of HeLa cells cultures was investigated. The significant perturbation of proteic biogenesis, the inhibition of HeLa tumoral cells cultures development, as well as the existence of a dose--response relationship argue the behaviour of these products as in vitro active cytostatic agents. This characterization justifies their introduction in the in vivo screening program on rats bearing of different experimental tumoral lines, for the preclinical pharmacological evaluation of the POLYAS I and POLYAS II vegetable polyphenols antineoplastic activity.

Effect of viral preinfection upon cell adherence in some staphylococcus strains from specific infections or carriers.

The adherence of bacteria to eukaryote cells has been largely investigated as an essential step in the occurrence of bacterial infection. Some clinical and epidemiological studies have revealed the frequent association of certain viral infections with bacterial infections originating in the same ecological niche. Therefore, we investigated the effect of the viral preinfection (ADV4) of some cultivated cells (HEp-2 and IC.SK-27) upon the adherence of staphylococcus to these cells. The analysis of cell adherence within the mentioned conditions, estimated by flow cytometry, allowed of the following conclusions: 1. bacterial adherence to cultivated and virally preinfected cells is augmented by the viral preinfection, and its value on a given cell substrate may characterize a bacterial strain; 2. bacterial adherence to the investigated cell substrates does not correlate with the origin of the tested staphylococcus strains (infections or carriers) and some cell lines can differentiate bacterial strains depending upon the ecological niche or inside it.

Effect of prostaglandin E2 (PGE2) and cyclic adenosine monophosphate (cAMP) upon actin cytoskeleton in human pulmonary fibroblasts (ICP-23) infected by measles virus.

The evolution of the actin cytoskeleton after trypsinization and recultivation as well as the effect of the PGE2 modulator and that of the secondary messenger, the cyclic AMP upon the same cytoskeletal proteins in human pulmonary fibroblasts (ICP-23) were studied. The substances were administered simultaneously and after one hour of viral adsorption. Using epifluorescence for pointing out filamentous actin the modifications occurring in this cytoskeletal protein when contacting trypsin and the virus and when PGE2 and cAMP are administered in the experimental variants are observed. Actin arrangement is obviously modified by the viral infection but the restrictive effect of PGE2 and cAMP upon virus replication is correlated with modifications occurring in the actin cytoskeleton.

Adaptation of the herpetic virus on human diploid and monkey kidney cells.

Viral suspensions of herpetic virus were inoculated on different cell cultures: human diploid cells (HDC) and monkey kidney cells--primary culture and cell line--for adapting the virus on these cells and obtaining several high constant titers. The human diploid cells and the monkey kidney cell line have proved to be the most suitable cells for the virus growth; thus an optimum development of the virus with a high constant titer was obtained starting with the 4th passage (10(5.7)-10(6)CPD/50/ml). The optimum conditions provided for the herpetic virus culture have allowed to obtain a herpetic virus stock used as control preparation for testing the efficacy of the "OFTALMOHERPIN" biological preparation for current use in the prophylaxis and therapy of ocular herpes.

The anti-initiator action of p-methoxyphenol phosphate upon the transformation of normal human embryo cells induced by benzo(a)pyrene.

The association of p-methoxyphenol phosphate (10(-5)M) to benzo(a)pyrene treatment (10(-6)M) reduced significantly the anchorage independent growth and the number of transformed foci of the human embryo lung fibroblasts, after six passages from treatment application. Results from cytogenetic analysis show that p-methoxyphenol phosphate induced the decrease of numerical and structural chromosome aberration after the first passage of the treated cells. In terms of the results obtained by cytogenetic analysis the reduction of genetic instability seems to remain constant from the first to the sixth passage in the cell cultures treated with p-methoxyphenol phosphate associated to benzo(a)pyrene.

In vitro effects of pulsed near-ultraviolet laser exposure on human larynx carcinoma cells.

Effects of pulsed near-ultraviolet laser beam on structural characteristics and macromolecular synthesis of carcinoma HEp2 cells were investigated. Laser irradiation damage induced in these eukaryotic cells could be characterized by two development stages: a) a reversible stage with minor morphological damages (1.5 kJ/m2) and 2) an irreversible one, at higher fluences, characterized by cellular membrane damage, necrobiosis and cells detachment from the substrate (4.5 kJ/m2). A. Studies performed referring to macromolecular syntheses of low laser fluences (1.5 kJ/m2)--irradiated HEp2 cells showed the following aspects: a) syntheses inhibiton phase in the first cycles of cellular replication and b) syntheses stimulation phases in the following cycle with total repair of laser-induced molecular lesions. B. At high laser fluences (3-4.5 kJ/m2), metabolic lesions repair was partially or totally blocked after prolonged culturing at 37 degrees C. Ths paper suggests some mechanisms of laser action on macromolecular synthesis and correlates them with morphological changes induced by laser exposure of carcinoma cells.

Prostaglandin E2 (PGE2) effect upon ICP-23 human pulmonary fibroblasts growth in culture and on measles virus multiplication in this cell type.

The influence of PGE2 in different concentrations (10(-4)M, 10(-6)M, 10(-8)M) and of 1 mM AMPc upon ICP-23 human pulmonary fibroblasts and also the influence of PGE2 upon measles virus multiplication in the same cell type were studied. PGE2 inhibited fibroblasts growth in all administered concentrations, depending on them. AMPc adding to human fibroblasts in culture progressively stimulated cells growth in the first 24 hours, produced a steady growth during 24-48-hour interval and slightly inhibited cellular divisions between 48 and 72 hours. PGE2, added in the same concentrations to measles virus--infected ICP-23 cells, concomitantly with virus administration and after 1 hour of viral adsorption influenced viral multiplication, depending on substance concentration and culturing period. Obtained data suggested that PGE2 in physiological concentrations (10(-6)M, 10(-8)M) initially has a weak inhibitory effect (titration after 6 days), but then stimulates viral production (9 days). The initial inhibition is more marked when the substance is added concomitantly with virus administration.

Laser effects on cellular adhesion and influence on the interrelation between HeLa S3 and human diploid cells.

The interactions between HeLa S3 tumoral cells and human fibroblasts after nitrogen-laser irradiation (337.1 nm) have been studied by using an in vitro cell invasion model. For the quantitative and morphological evaluation of nitrogen-laser radiation action upon tumoral adhesion to the fibroblast monostrate, we used: a) 3H-thymidine labelling of HeLa S3 tumoral cells; b) morphological modifications studies by phase contrast and scanning electron microscopy. The results emphasized the following aspects: 1. In non-irradiated cell cultures we noticed three interaction stages: adhesion, tumoral spreading and displacement with fibroblasts destruction; on the other side, we found a reduced adhesion to non-irradiated human fibroblasts of laser irradiated tumoral cells. 2. Significant percent increasing of non-irradiated tumoral cells adhesion to fibroblast monostrate, irradiated with various laser fluences (e.g. 0.2 kJ/m2--48.1%; 0.8 kJ/m2--63.8% and for 1.6 kJ/m2--79.5%). This phenomenon evidenced the close interrelation between irradiation fluences and tumoral adhesion rates. 3. The importance of numerical ratio between tumoral cells and fibroblasts in tumoral adhesion and invasion processes (e.g. ratio 1:10 tumoral adhesion reached 8.1%; in 1:5--25.9%; in 1:1--59.4% and for 2:1--83.9%). 4. Marked cytotoxic effects for both cell types after exposure to high and very high laser fluences (1.6--6.4 kJ/m2). Our results emphasize near UV-laser irradiation effects upon some of tumoral adhesion and invasion mechanisms and demonstrate the interrelations between cell populations manifesting a different vital potential.

The protective effect of Thiola against the genotoxic action of benzo(a)pyrene.

The protective effect of Thiola against the genotoxicity, induced by benzo(a)pyrene, in vitro and in vivo, was investigated. By association of Thiola to benzo(a)pyrene a significant decrease of the numerical and structural chromosome aberrations and a reduction of the incidence of c-mitoses has been obtained in human diploid cells, i.e. human embryonic lung fibroblasts of the cell-line ICP-23, and C56B1/6 mouse bone marrow cells.

Some characteristics of the ICCe-1, a new simian embryo cell line.

A new simian embryo cell line has been established from a Cercopithecus male whole embryo. The resultant predominant fibroblast-like cell population has been frozen in convenient quantities and characterized for use in biological research as well as in theoretical and practical virological purposes. The cell line was designated ICCe-1 (Institute Cantacuzino Cercopithecus embryo-1).