Paola Bigatti

Occupational exposure to formaldehyde and biological monitoring of Research Institute workers

AIM The aim of this study was to verify the presence of a relationship between formaldehyde exposure in the work environment with biological markers of exposure and of effect. METHODS Exposure to formaldehyde (FA) of 36 workers in different laboratories of a Cancer Research Institute and biomarkers of exposure, such as formaldehyde human serum albumin conjugate (FA-HSA) and biomarkers of effect, such as chromosome aberration (CA), micronuclei (MN) and sister chromatid exchanges (SCEs) were measured in peripheral blood lymphocytes of the same workers. RESULTS Individual FA levels of exposure ranged from 4.9 microg/m(3) to 268.7 microg/m(3). Subjects with high FA exposure showed a significant increase of the biomarker of exposure FA-HSA, but biomarkers of effect did not show any significant differences. CONCLUSIONS A significant relationship was observed between occupational exposure to FA and a biological marker of exposure (FA-HSA). The markers of effect used (CA, MN and SCE) failed to indicate the presence of genetic damage.

Cytogenetic monitoring of hospital workers exposed to low-level ionizing radiation

In the present study the cytogenetic effects in hospital workers exposed to low-level radiation were evaluated. Samples of peripheral blood were collected from 63 subjects working in radiodiagnostics and from 30 subjects, working in the same hospitals, who were used as controls. A higher number of cells with chromosome-type aberrations (CA) was observed in the exposed workers vs. the controls and the difference was statistically significant (p less than 0.05). No correlation was, on the contrary, found between CA and years of exposure. A significant difference was observed in the incidence of cells with CA between smokers and non-smokers, but in the control group only. In contrast, in the workers exposed to ionizing radiation, the frequency of cells with CA was very similar in smokers and non-smokers.

The Banded Karyotypes of Macaca fuscata Compared with Cercocebus aterrimus

The karyotypes of Macaca fuscata and Cercocebus aterrimus are compared after G, C and AgNOR banding. Although it is often assumed that the 42-chromosome monkeys (species of the genera Macaca, Papio, and Cercocebus) are identical at the chromosomal level, a number of clear and consistent differences between the karyotypes of these two taxa are described. These differences include one pericentric inversion and differences in staining intensity, particularly in centromeric and pericentromeric areas. It is probable that high resolution chromosome techniques could reveal more differences between taxa in the 42-chromosome group than are now believed to exist. It is therefore probable that karyological data could provide insight into the phylogenetic relationships in this group of Old World monkeys.

No correlation between chimerism and fertility inCallithrix jacchus (Callithricidae, Primates)

In this study, 40 individuals ofCallithrix jacchus were analyzed in order to investigate the frequency of chimerism and to determine whether the fertility of the colony was in any way affected by chimerism.In the individuals considered the degree of chimerism ranged from 2% to 97% and no correlation was established between the degree of chimerism and fertility of the individuals. Many “good breeders” were chimeric and the best female breeders displayed 84% and 97% chimerism respectively.

Comparison of chromosome aberration frequency before and after administration of 131I in two groups of thyroid cancer patients.

The chromosome aberration frequencies of 10 thyroid cancer patients, before and after their first radioiodine treatment (group A), were compared to the frequencies found in another 10 subjects previously treated with two or more radioiodine administrations (group B). Our data show that the relative increase in chromosome-type aberrations was similar in the two groups: from 2.0% to 3.7% (group A) and from 4.7% to 9.0% (group B). However, the increase in the number of cells with aberrations was greater in group A. Moreover, the higher frequency of aberrations in group B, even before the radioiodine treatment, points out the effect of previous treatments and demonstrates the persistence of this type of lesion. The sister chromatid exchange frequency in the two groups was also analysed, but no effect bound to the radioiodine treatment could be demonstrated.

The effect of cell kinetics and harvest time on SCE and NOR associations in Macaca fuscata lymphocytes

The relationship between cell kinetics and cell harvest time on sister chromatid exchange (SCE) and NOR (marker chromosome) association was investigated in cultured Macaca fuscata lymphocytes. The average number of SCEs in individuals ranged from 3.77 to 9.07 per cell. The highest SCE rate was found in cultures harvested at 60 h. The data suggest a decrease in SCE frequency between 60 h and subsequent cell harvest at 72, 84, and 96 h. NOR association frequency was also affected by cell kinetics, as well as by cell harvest time. The highest association frequencies were at 48 h, when the number of first mitoses was greatest.

Sister-chromatid exchange rates in XX and XY cells of ten chimeric Callithrix jacchus individuals.

In order to ascertain whether or not sister-chromatid exchange (SCE) differs in relation to sex, SCE rates in XX and XY cells from 10 specimens of marmoset (Callithrix jacchus) were examined. The choice of this primate is particularly suitable for three reasons: most individuals have a chimeric constitution, the X chromosome is quite large and the Y chromosome is particularly small. Therefore, the influence of possible differences in their exposure to the external environment can be eliminated. The results obtained did not reveal any significant difference between SCE rates in male and female cells in any of the examined individuals.

Frequency and non random distribution of silver-staining NORs on acrocentric chromosomes from neonate and adult human lymphocytes

The NORs frequency in a group of newborns and adults was determined by the gelatine silver staining technique. A higher number of Ag-NORs (χ2 test, p<0.01) was found in adults than in newborns. The lack of correlation between cell proliferating rate index (PRI) and frequency of Ag-NORs let us suppose that the decrease of Ag-positive NORs in neonates could probably be due to factors different from cell kinetics.A non random distribution of Ag-NORs on the acrocentric chromosomes was also demonstrated: chromosome 21, in particular, showed the highest frequency, while chromosome 15, the lowest.

Comparative analysis of DNA restriction patterns ofHomo, Pan troglodytes eMacaca fascicularis after hybridization with human genomic probes: β1-Integrin, pAW101 anderb-B2

In the present work, Eco RI digested genomic DNA fromMacaca fascicularis, Pan troglodytes and Man were hybridized with three human probes (β1-Integrin, pAW101; anderb-B2) and the relative restriction patterns are presented.After hybridization with theβ1-Integrin probe it was possible to demonstrate a high intraspecific variability in the Macaca and Pan sample, while the other two probes utilized didn’t show any difference among the different species considered.In order to calculate the phylogenetic distances, some mathematical models are available, however severe limits exists at present in their application.