Polyploid cells

The incidence of nuclear anomalies in bone marrow interphase cells significantly increased (p<0.05) in Chinese hamsters gavaged on 2 consecutive days with 2,500 and 5,000 mg/kg/day of Reofos 50 (Ciba-Geigy 1984a), but not in those dosed with 1,250 mg/kg/day. The types of anomalies used in scoring were single "Howell-Jolly" bodies, fragments of nuclei in erythrocytes, micronuclei in erythroblasts, micronuclei in leucopoietic cells, and polyploidal cells. 

Leevers It is unnecessary most larval (polyploid) cells are going to lyse during metamorphosis. 

Fig. 8. Root tip cells of A. cepa treated with 100 mg L 1 COL showing the presence of polyploid cells (PC) at magnification of 400x (A) and lOOOx (B).

Musc/skel = musculoskeletal N = haploid cells 4N = polyploid cells NOAEL = no-observed-adverse-effect level NS = not specified Resp = respiratory (W) = water wk = week(s)... 

Chromosome damage Incidence of cells with structural chromosome aberrations including and excluding gaps (including number and type of aberrations), as well as polyploid cells and cells with endoredupUcated chromosomes. 

Immediately after sacrifice, bone marrow cells are collected from femurs or tibias, exposed to hypotonic treatment, fixed, spread on slides, and stained. The slides are then scored visually under the microscope. Structural chromosome aberrations should be analyzed in at least 100 metaphase cells per animal. To this end, for each cell, the number and type of aberrations (chromatid or chromosome breaks and gaps, as well as the different types of chromatid and chromosome rearrangements) should be recorded. The incidence of polyploid cells and of cells with endoreduplicated chromosomes should also be reported because they potentially reflect the induction of numerical chromosome aberrations and/or inhibition of cell cycle progression. In addition, the mitotic index, used as a cytotoxicity parameter, is calculated for 1000 cells per animal. With cytotoxic compounds, the highest dose level should induce at least a 50% reduction in the mitotic index (OECD 1997b Richold et al. 1990 Tice et al. 1994). 

F. Constabel, W. G. W. Kurz, and W. H. J. Tam. GB2045243A. 25-02-1980-GB-8006252 (2I-03-I979). Codeine production from opium poppy and using culture of cytodifferentiated polyploid cells. 

A more specific effect of ABA on cell division may be involved in the suppression of root nodulation in pea (Phillips 1971). Nodule tissue develops primarily from the division of polyploid cells, and the withdrawal of ABA from roots after transient exposure to the hormone has been reported to stimulate mature polyploid cells to divide (Nagl 1972). 

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