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G Decat

Publications and source records attributed to G Decat.

32 records · Page 2Linked to original sources
PubMed1980

[Chromosomal anomalies induced by X-rays in lymphocytes of the gorilla].

Using the harlequin--staining technique to distinguish the first from later mitotic divisions we have studied the frequency of spontaneous and radiation-induced sister chromatid exchanges and chromosome aberrations in peripheral blood lymphocytes from gorilla, the results being compared with previous findings on man. In spite of the fact that the karyotypes of the two species closely resemble each other the incidence of radiation-induced chromosome aberrations was much higher in gorilla than in man. The mean number of sister chromatid exchanges was not modified by exposure to X-irradiation and was almost similar in the two species.

Animals↗
PubMed1979

Relation between cell cycle and yield of aberrations observed in irradiated human lymphocytes.

The bromodeoxyuridine-Giemsa technique has been used to study systematically the incidence of cells in first or subsequent mitoses at different fixation times of human lymphocyte control cultures as well as the influence of ionizing radiations on cell kinetics. Second divisions appear (3%) in cultures harvested 48 h after initiation. In 72 h cultures 40% of the dividing cells are in second and 33% in third division. Administration of 200 rads of X-rays before PHA stimulation results in a mitotic delay but does not increase the incidence of SCE. The yield of dicentrics after an exposure to 200 rads was the same for all cells in first mitosis regardless of fixation time. These results demonstrate that there is no evidence for the existence of sensitive subpopulations that could be distinguished by the time of the first mitotic division following stimulation.

Cell Cycle↗
PubMed1979

[Kinetics of division of human and rabbit lymphocytes stimulated by phytohemagglutinin, studied by means of the bromodeoxyuridine (BUDR) technic].

The BUDR-Giemsa technique has been used to distinguish the first from later divisions for man and rabbit lymphocytes stimulated by treatment with phytohemagglutinin. At 48 hours, 99% of human lymphocytes exposed to 200 rads of X-rays are in first division whereas 45% of the rabbit lymphocytes are already in second division and 28% in third division.

Adult↗
PubMed1977

The radiosensitivity of chromosomes of rabbit lymphocytes.

Dicentrics were induced in human and rabbit lymphocytes in vitro by exposure to X-irradiation. The yields were compared with data reported in the literature. To elucidate the reasons for the different findings we have evaluated the parameters for the different models by maximum likelihood methods. From this analysis it can be concluded that the earlier claim of Bajerska and Liniecki [1] that both species have the same radiosensitivity must be discounted, and that their similarity was due to the abnormally low values these investigators observed in irradiated human lymphocytes.

Animals↗
PubMed1977

The chromosomal radiosensitivity of lymphocytes from the chimpanzee (Pan troglodytes).

The yield of chromosomal aberrations induced by exposure to X-irradiation in vitro was studied in the lymphocytes of the chimpanzee (Pan troglodytes), a hominoid ape phylogenically and chromosomally closely related to man. In agreement with the similarity of the chromosome characteristics, no significant difference was observed between man and chimpanzee with respect to the incidence of dicentrics and fragments. It is obvious that the nuclear area, which apparently constitutes the most evident difference between the nuclei of man and chimpanzee lymphocytes, did not play an important role in the yields of aberrations.

Animals↗
PubMed1977

Cytogenic investigations on leucocytes of cattle intoxicated with fluoride.

Cattle which grazed in the vicinity of a plant manufacturing enamel and which displayed signs of chronic fluoride poisoning such as osteosclerosis and mottled enamel or dental fluorosis were investigated for the presence of structural chromatid and chromosome aberrations. Venous blood was incubated for 48 h, and 100 cells were analyzed for each animal. No statistical difference in the incidence of such anomalies was observed between the controls and the intoxicated animals.

Animals↗
PubMed1977

Cytogenetic investigations on lymphocytes from workers exposed to vinyl chloride.

Eleven male workers from the polymerization department of a vinyl chloride factory, seven people employed in the laboratory of another vinyl chloride plant, and ten controls from outside the factory environment were examined for the presence of chromosome aberrations in blood lymphocytes. Chromosome anomalies such as fragments, rings, translocations, and dicentrics were observed in most of the workers from the polymerization department. However, the medical history of these workers shows that they received frequent radiographs of the hands, feet, vertebral column, and digestive tract. It is therefore impossible to determine whether these chromosome anomalies result from vinyl chloride exposure.

Adult↗
PubMed1977

[Modified Giemsa technique for the study of characteristic chromosomes of leukemic C57Bl mice].

G-banded karyotypes have been studied in C57Bl control mice and in animals developing leukemia after i.p. injection of acellular extract of spleen or lymph nodes from isologous animals showing radiation induced leukemia. No visible differences could be detected with respect to the number, size and position of the G-bands between the two groups of animals. From the present observations and from previous work with conventional staining methods, it can be concluded that the development of such leukemia does not involve the presence of chromosome abnormalities.

Animals↗
PubMed1976

The radiosensitivities of lymphocytes from pig, sheep, goat and cow.

Dose-effect curves for X-irradiation in vitro were determined on cultured blood lymphocytes of four mammalian species-cow, goat, sheep and pig-having approximately the same number of chromosome arms, the same nuclear volume and the same DNA content. The data from cow, but not those from the other species, exhibited significant inhomogeneity between the experiments. On inspection the numerical yields appear not to differ greatly in the lower dose range. Evaluation of the parameters according to the quadratic law and the power law, however, demonstrate significant differences. Pig differs from the other species regardless of which presentation is chosen. For the power law a significant difference is also found between goat and sheep.

Animals↗
PubMed1976

Identification of the mouse chromosomes by microdensitometry.

Densitometric analysis has been performed on mouse chromosomes from "in vivo" preparations stained with Giemsa after trypsinisation. The characteristic curves obtained by analysing the same chromosome after different durations of trypsinisation suggest that a trypsinisation step is not always necessary to get an analysable banding pattern. The best results are obtained when the chromatids are long and closely appressed and by analysing the positive photomicrographs.

Animals↗
PubMedDate not supplied

Chromosome aberrations in employees from fossil-fueled and nuclear-power plants.

Chromosome aberrations were scored in 59 persons from fossil-fueled plants, in 89 persons from nuclear-power plants and in 23 controls. A significant increase in acentric chromosome fragments and dicentric chromosomes compared to the control group was observed in both types of workers. Moreover, the number of abnormal cells was significantly greater in workers of conventional plants than in those of nuclear-power plants. When adjusted for loss of lymphocytes according to a half-life of 3 years, this difference was also significant for the number of dicentric chromosomes observed. A significant effect of length of exposure or of frequency of radiological examinations could be discerned only in the group of workers from conventional plants.

Adult↗
PubMedDate not supplied

Lack of mutagenic activity of dimethylformamide.

Different test systems have been utilized to evaluate the mutagenic and carcinogenic properties of dimethylformamide (DMF), an aliphatic amide used as a solvent in chemical industry. The Ames test was performed on different strains of Salmonella typhimurium, whereas the ability of DMF to induce structural aberrations in eukaryotic chromosomes was tested by in vitro observations on human lymphocytes and in vivo experiments on mouse bone marrow. Furthermore, male mice were treated with DMF for the induction of sperm abnormalities. The negative results obtained in all test systems as well as the absence of positive reports in man or in experimental animals with respect to induction of cancers suggest strongly that DMF is devoid of mutagenic or carcinogenic properties.

Animals↗