Taking into account the numbers of MONO, BN, and polynucleated cells, the cytokinesis block proliferation index (CBPI) can be calculated to provide an estimate of the in vitro division rate.
In the present study of a well-documented NewGeneris cohort of mother-newborn pairs (the Rhea cohort from Greece-Crete), we used the CBMN assay to determine MN frequencies in both MONO and BN T lymphocytes and to derive the CBPI in 251 newborns and 223 mothers, including 182 mother-child pairs.
After validation, the total numbers of mono- and binucleated T lymphocytes with MN (MNMONO and MNBN, respectively) and without MN, and the CBPI, were recorded in a data file.
Multivariable linear regression analysis with backward selection was used to identify maternal and child factors that were significant predictors of the different genotoxicity parameters (MNBN, MNMONO, and CBPI).
Median CBPI values in maternal samples (1.70) were statistically significantly higher than those in cord blood (1.58;p < 0.001).
None of the variables included in the initial model (maternal age, birth weight, child sex, maternal BMI, GA, delivery type, preterm status, smoking, and supplement intake) were significant predictors of MNBN and CBPI among the 173 children with complete data for all potential predictors (Table 3).
As for all births combined, no variables significantly predicted MNBN frequency or CBPI (Table 3).
Next, we performed multivariable regression analysis for the full-term infants with paired samples from their mothers to estimate associations with maternal genotoxicity parameters (MNBN, MNMONO, and CBPI) in addition to the variables evaluated previously (data not shown).
We detected no effect on cell-cycle kinetics, measured as CBPI, as a consequence of the solvent exposure.
Age appeared to be partially associated with a decreased cell proliferation, as indicated by its significant effect on PRI (p = 0.001); CBPI was not affected by age.
Tables 6 and 7 show the average of BNMN, CBPI, SCEs, HFC, and PRI values for GSTM1 positive and GSTM1 null subjects among the different subgroups.
BNMN/1,000 cells CBPI Controls Nonsmokers 20 24.15 [+ or -] 7.49 1.89 [+ or -] 0.16 Smokers 16 22.19 [+ or -] 8.45 1.87 [+ or -] 0.11 Plant A workers Nonsmokers 15 31.13 [+ or -] 10.01 1.93 [+ or -] 0.08 Smokers 18 25.28 [+ or -] 12.13 1.89 [+ or -] 0.09 Plant B workers Nonsmokers 8 47.25 [+ or -] 9.10 1.85 [+ or -] 0.20 Smokers 11 43.45 [+ or -] 13.47 1.95 [+ or -] 0.17 Total Controls 36 23.28 [+ or -] 7.87 1.88 [+ or -] 0.14 Plant A workers 33 27.94 [+ or -] 11.44 1.91 [+ or -] 0.09 Plant B workers 19 45.05 [+ or -] 11.69 1.91 [+ or -] 0.19 SCE assay (b) Group No.