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Biomedical subjects

G Deysson

Publications and source records attributed to G Deysson.

At least 19 recordsLinked to original sources
PubMed1982

Effect of sodium cis-beta-4-methoxybenzoyl-beta-bromacrylate (Cytembena) on HeLa cell kinetics.

The treatment of HeLa cells with various concentrations of sodium beta-4-methoxybenzoyl-beta-bromacrylate (Cytembena) results in inhibition of growth and modification of cell cycle distribution. These phenomena were observed at concentrations between 7.5 x 10(-5) and 2.5 x 10(-5) M. The estimation of DNA content by flow cytometry showed an important shift in the distribution of cycling cells with a relative decrease of G0 + G1 cells and a striking accumulation of G2 + M cells. According to our experimental conditions, the blocking up in G2 + M is irreversible at 7.5 and 5 x 10(-5) M.

Acrylates↗
PubMed1982

Effects of oxazaphosphorine cytostatics on granuloid progenitor cell (CFUc) proliferation in mice.

The effects of oxazaphosphorine cytostatics were studied on granulocytic/monocytic colony forming cells from mice bone marrow in methylcellulose culture. Cyclophosphamide, ifosfamide, trofosfamide and two secondary metabolites show a weak activity in vitro (Inhibitory Dose--50% (ID50) between 5 X 10(-4) M and 5 X 10(-5) M). By contrast, a high cytostatic activity was observed with phosphoramide mustard and especially with hydroperoxycyclophosphamide (ID50: 2.5 X 10(-6) and 4 X 10(-7) M). These results suggest that these metabolites are active. The differentiation of the three types of colonies (granulocytic, monocytic and mixed) showed no specific effect of the drugs for a given series. After in vivo treatment, cyclophosphamide, ifosfamide and trofosfamide induce an important decrease of nucleated bone marrow cells. This decrease is maximum on the third day and regresses when the treatment is interrupted. On the first day of the culture an inhibition of the proliferation of granulocytic/monocytic progenitor cells is observed. An important statistically significant stimulation of these same progenitor cells is however noted later.

Alkylating Agents↗
PubMed1981

[Comparison of the antimitotic properties of cyclophosphamide and its biotransformation products on meristema plant cells and animal cells in in vitro culture].

N-mustard diamide phosphoric and above all 4-hydroperoxycyclophosphamide are clearly more cytotoxic than same kind, which is in accordance with the fact that these compounds are the active metabolites of cyclophosphamide. On the contrary, 4-ketocyclophosphamide and carboxyphosphamide, secondary metabolites inapt to be activated, are not more cytotoxic than cyclophosphamide. No tolerance does occur with these metabolites, contrary to cyclophosphamide itself.

Animals↗
PubMed1981

Effect of three alkylating antimitotic agents and their metabolites on in vitro monogranulocytic colony forming cells from mouse bone marrow.

The effects of oxazaphosphorine cytostatics were studied on monogranulocytic colony forming cells from mouse bone marrow in methylcellulose culture. Cyclophosphamide, ifosfamide, trofosfamide and two secondary metabolites showed a weak activity (ED50 between 5 x 10(-4) mol/l and 5 x 10(-5) mol/l). On the contrary, a high toxicity was observed with phosphoramide mustard and especially hydroperoxycyclophosphamide (ED50: 2.5 x 10(-6) mol/l and 4 x 10(-7) mol/l). These results suggest that these metabolites are the carriers of cytotoxic specificity. The differentiation of the three types of colonies (granulocytic, monocytic and mixed) revealed no specific effect of the drugs for a given series. On the other hand, the staining of colonies revealed some mitotic abnormalities (agglutination bridge, micronuclei and cytodieretic alteration).

Alkylating Agents↗
PubMed1980

[Inhibitory effect of cytembena (sodium-cis-beta-methoxybenzoyl-beta-bromoacrylate) on the cell kinetics of HeLa cells in culture].

The inhibiting effect of Cytembena on HeLa cell kinetics has been demonstrated and analyzed. The percentage of cycling cells decreases, according to the concentration, between 7.5 and 2.5 x 10(-5) M. Estimation of DNA by cell flow cytophotometry shows an important shift in the distribution of cycling cells with a relative decrease of G1 cells and a very important accumulation of G2 cells. According to our experimental conditions, the blocking up in G2 is irreversible only at 7.5 x 10(-5) M.

Acrylates↗
PubMed1979

[The action of antimitotics and the cell cycle].

Cell kinetics, which for a long time could only be worked out at the level of mitosis, has now at its disposal a set of technics which make it possible to label cells which replicate their DNA, to appraise the DNA content of individual cells and to synchronise cell populations. First of all, the meaning and the scope of results obtained by cell kinetics technics in the study of the action mechanism of antimitotic substances are discussed. The main results obtained are exposed, pointing to the complexity of the mechanisms concerned. A more detailed discussion of some personal results concerning the action of anti-inflammatory substances, of protein inhibitors and of hydroyure allows to underline the difficulties met with and the importance of the choice of an adequate methodology.

Animals↗
PubMed1978

Contribution to the understanding of the mechanism of cytokinesis in plant cells: the action of deoxyguanosine on the kinetics of a root meristem cell population.

The kinetics of binucleate cells, formed by the action of deoxyguanosine, are studied using three methods: in a population synchronized with hydroxyurea, by autoradiography after pulse-labelling, and in a sample of a cell population morphologically located at the M--G1 limit. Deoxyguanosine induces a slowing down in S and G2, independent of the inhibition of cytokinesis. It is only when it takes effect during the G2 stage that deoxyguanosine brings about the formation of binucleate cells.

Cell Cycle↗
PubMed1977

[Cell kinetics and experimental rearrangement of daughter chromosomes at the end of mitotic division].

The action of hexamethylene-tetramine (HMT), which causes a late disorientation of the two sets of chromosomes during telophase in Allium sativum L. meristematic root cells, has not been found again, in the same material after synchronization by hydroxyurea. The explanation put forward takes into account the special feature of cells synchronized by chemical methods. Besides, the toxicity of HMT is not the same according to the stage of the cell cycle during the treatment.

Cell Division↗
PubMed1977

[Partial disorganization of the anaphasic segregation of chromosomes in plant cells: combined actions of griseofulvin, producer of pluripolar anaphases and 2 ipecac alkaloids, producers of floating pole anaphases].

Anaphasis may be slightly checked by various treatments which however result in a normal chromosomic separation. Griseofulvin exerts a direct though partial influence on the mitotic apparatus, which entails "pluripolar anaphasis"; on the other hand Ipecac alkaloïds act indirectly and produce "floating poles anaphases". Treatments combining griseofulvin with cepheline or tubulosine show that there is never any synergy between the two processes. These results support our hypothesis that floating poles anaphases are not a sign of slight C-mitotic action but only come from a lag between the appearance/disappearance of microtubules and that of chromosomes during anaphasis.

Anaphase↗
PubMed1976

[New researches on protein synthesis inhibition under the action of aurintricarboxylic acid during cell cycle : Study on meristematic cells of Allium sativum L].

Aurin tricarboxylic acid, an inhibitor of protein synthesis, prevents cells from entering mitosis in Allium sativum L. root meristems. When the uptake of 3H-leucine comes back up to the control rate after removal of roots from the drug, mitotoic activity is resumed. Furthermore, the percent of labelled cells obtained by continuous labelling with H3-thymidine shows a reversible arrest of cell progress from G1 to S.

Aurintricarboxylic Acid↗
PubMed1976

[Kinetic study of the accumulation of anaphasic abnormalities in a synchronized population of meristematic root cells of Allium sativum L].

A population of meristematic root cells of Allium sativum L. is previously synchronized thanks to Hydroxyurea. When it reaches mitosis, this population undergoes the action of different antimetabolic drugs which slightly check the normal operating of the mitotic spindle without preventing chromosomic separation. In such conditions we can obtain from 30 to 50 slightly altered anaphasic cells out of 1000 cells. This is enough to allow us to contemplate the electronic microscope study of these abnormalities.

Antimetabolites↗
PubMed1976

[Modality of the antimitotic acitivity of the diamine cis-dichloroplatinum (II) studied on the plant cell].

In the order of decreasing doses, cis-platinum (II) diamine dichloride acting on root meristem of Allium sativum produces first an irreversible metostatic effect quickly followed by lethal effect, then a variable mitodepression accompanied by important chromosomal alterations: numerous disruptions and stickiness. This chromatoclasic effect persists at very low concentrations but stathmodieretic effect is not observed. The chromatoclasic activity of the compound is compared to that of other antitumoral drugs.

Cisplatin↗