Alfredo Santovito

Allele and haplotype diversity of X-chromosomal STRs in Ivory Coast

Twenty-one X-chromosomal short tandem repeat (STR) loci, including the six clusters of linked markers DXS10148–DXS10135–DXS8378 (Xp22), DXS7132–DXS10079–DXS10074 (Xq12), DXS6801–DXS6809–DXS6789 (Xq21), DXS7424–DXS101 (Xq22), DXS10103–HPRTB–DXS10101 (Xq26), DXS8377–DXS10146–DXS10134–DXS7423 (Xq28) and the loci DXS6800, GATA172D05 and DXS10011 were typed in a popula3tion sample from Ivory Coast (n = 125; 51 men and 74 women). Allele and haplotype frequencies as well as linkage disequilibrium data for kinship calculations are provided. On the whole, no significant differences in the genetic variability of X-STR markers were observed between Ivorians and other sub-Saharan African populations belonging to the Niger–Kordofanian linguistic group.

Combined Analysis of Chromosomal Aberrations and Glutathione S-transferase M1 and T1 Polymorphisms in Pathologists Occupationally Exposed to Formaldehyde

The formaldehyde (FA) genotoxic potential in occupationally exposed individuals is conflicting. A relevant indoor-air FA pollution was found in hospitals and scientific institutions where FA is used as a bactericide and tissue preservative. In the present study, we evaluated the frequency of chromosomal aberrations (CAs) in peripheral blood lymphocytes from workers in pathology wards who have been exposed to FA, compared with a group of unexposed subjects. The subjects were also analyzed for the GSTM1 and GSTT1 metabolic gene polymorphisms. The exposed subjects showed a significant increase in the frequency of CA per cell and in the percentage of cells with aberrations compared to control subjects. The different GST genotypes did not affect the level of cytogenetic damage since CA frequencies were not statistically different between the GST “null” genotypes and the GST “positives”. The generalized linear models showed that the number of CAs and cells with CAs increased with age, but, independent of age, it was significantly higher in the experimental rather than in the control group. Cubic-spline regression confirmed the linear relationship between CAs and age, but it provided evidence for a non-linear relationship between CAs and the number of years of FA exposure. Similar results were observed when the model included the number of cells with CAs as dependent variables. Our results demonstrate that air FA induces CAs even consequently to low levels of daily exposure, indicating an increased risk of genetic damage for workers exposed to this air pollutant.

Increased frequency of chromosomal aberrations and sister chromatid exchanges in peripheral lymphocytes of radiology technicians chronically exposed to low levels of ionizing radiations

Chromosome aberrations (CAs) and sister chromatid exchanges (SCEs) frequencies were estimated in peripheral lymphocytes from 21 radiology technicians, and from 21 non-exposed control subjects. We exclusively considered individuals who neither smoke nor consume drugs or alcohol for a period of at least two years prior to the analysis. Significant differences were found between exposed and controls in terms of SCEs and CAs frequencies. Technicians showed a significant higher number of high-frequency individuals (HFIs) with respect to the control group. Nevertheless, the mean frequency of SCEs observed among technician HFIs did not significantly differ with respect to that observed among control HFIs. Vice versa, the non-HFIs belonging to technicians group showed a statistically higher difference in the SCEs/NSM value with respect to the non-HFIs belonging to control group. Since the differences in the SCEs frequencies between the two groups are due to non-HFIs, our results seem to indicate a general genotoxic effect of the IR, not affected by HFIs. Among technicians, the level of chromosome damage correlated neither with years of radiation exposure nor with the age of the subjects. Vice versa, in the control group, a positive correlation was found between the number of SCEs and age. In both samples the gender status did not influence the frequencies of CAs and SCEs. Our results suggest that chronic long-term exposure to low doses of ionizing radiation could increase the CAs and SCEs frequencies. This study reinforces the relevance of the biomonitoring of hospital workers chronically exposed to ionizing radiation.

Polymorphisms of cytochrome P450 1A1, glutathione s-transferases M1 and T1 genes in ouangolodougou (Northern Ivory Coast)

In this study, the frequencies of CYP1A1, GSTM1, and GSTT1 gene polymorphisms were determined in 133 healthy individuals from Ouangolodougou, a small rural town situated in the north of the Ivory Coast. As appeared in several published studies, ethnic differences in these frequencies have been found to play an important role in the metabolism of a relevant number of human carcinogens. In the studied sample, the frequencies of Ile/Ile (wild type), Ile/Val (heterozygous variant), and Val/Val (homozygous variant) CYP1A1 genotypes were 0.271, 0.692, and 0.037, respectively. Frequencies of GSTM1 and GSTT1 null genotypes were 0.361 and 0.331, respectively. No significant differences were noted between men and women. In contrast to published data for Africans, CYP1A1 *Val Allele frequency (0.383) was significantly high (p < 0.001) in this specific population. For the GSTT1 null genotype, no differences were found between the studied and other African populations, the contrary to what occurred for the GSTM1 null genotype in relation to Gambia and Egypt.

DAT1 VNTR polymorphisms in a European and an African population: identification of a new allele.

ABSTRACT Polymorphism frequencies of the dopamine transporter gene (DAT1) hypervariable region have been analyzed in a sample of Italian and Ivory Coast individuals. The 3′untranslated region (UTR) of DAT1 includes a variable number of tandem repeats (VNTR) of a 40-bp monomer, ranging from 3 to 13 repeats in Caucasian and African populations. In our sample we found alleles with 3 to 16 repeats, and the most common alleles were the 10-repeat (DAT1*10) and the 9-repeat (DAT1*9) alleles. We also found two rare alleles in the Italian population and four in the Ivory Coast population. For the first time the new allele DAT1*16 is described in the Ivorians. The Ivory Coast population was not in Hardy-Weinberg equilibrium for the DAT1 locus because of a deficit of heterozygote genotypes. The observed heterozygosity of the Ivorian population was half that of the Italians. The lower observed heterozygosity and deviation from Hardy-Weinberg equilibrium could be the result of microevolutionary trends, such as genetic drift and/or inbreeding, acting on the relatively small and isolated population sampled for this study, although some sort of selective pressures acting against the shorter alleles cannot be excluded. This evidence, in association with the reduced polymorphism shown by the DAT1 VNTR compared to other VNTRs, seems to indicate that the DAT1 locus may be under some selective pressure.

Chromosomal damage in peripheral blood lymphocytes from nurses occupationally exposed to chemicals

In the present study, we evaluated the induced genome damage in peripheral blood lymphocytes from a sample of nurses occupationally exposed to low doses of different chemicals. A comprehensive multi-biomarker approach using cytogenetic endpoints was employed for analyzing chromosomal aberrations (CAs) and sister chromatid exchange (SCE) assay. The study included 20 nurses and 20 control subjects matched in age, gender and smoking habits. Nurses were exposed to different chemicals, such as cytostatic drugs, anaesthetics, formaldehyde and other sterilizing gases. Significant differences were found between exposure group and control group in terms of SCEs frequency (p < 0.001) but not in terms of replication index value (p = 0.845) and CAs (p = 0.236). Regression analyses indicated that the age and the exposure years did not influence the amount of the chromosomal damage among nurses. Vice versa, among controls, a positive correlation was found between the number of SCEs and age. In conclusion, our results suggest that a continuous long-term exposure to low doses of chemicals could result in increased levels of SCEs among nurses. This data emphasize the importance of biomonitoring nurses and other hospital workers handling drugs.

Micronucleus frequency in human lymphocytes after exposure to diphenylamine in vitro.

Diphenylamine (DPA) is an antioxidant compound that occurs naturally in several vegetables. It is widely applied in agriculture for preservation of the quality of apples and pears, and used for controlling superficial scald, a disorder that renders fruits of a number of apple cultivars unfit for the market. Because of its anti-oxidative properties, DPA also has several industrial applications. The potential genotoxic effect of DPA on human lymphocytes has previously been investigated in only two studies, which focused on detection of chromosome aberrations and sister chromatid exchange, respectively. In the present analysis, we evaluated micronucleus (MN) formation in freshly isolated human peripheral lymphocytes exposed to different concentrations (0.625, 1.25, 2.50, 5.0 and 10.0μg/ml) of DPA. Peripheral venous blood was collected from ten healthy subjects, and a total of 10,000 bi-nucleated cells were analyzed. Results indicated that DPA significantly increased the micronucleus frequency at concentrations of 1.25μg/ml and higher. Significant differences in the MN frequency were also found between the lower dose (0.625μg/ml) and all other doses tested, with the exception of 1.25μg/ml. Our results indicate a potential cytogenetic effect of DPA on human cells in vitro and require further in vivo studies to clarify the actual genotoxicity of this compound and the consequent risks for human health.

Genotyping for cytokine polymorphisms in a Northern Ivory Coast population reveals a high frequency of the heterozygote genotypes for the TNF-α-308G/A SNP

Cytokine polymorphisms influence the outcomes of parasitic diseases and vary among populations because of their different evolutionary histories and selective pressures imposed by host–pathogen interactions. In this frame, we investigated the frequencies of TNF‐α (‐308G/A), TGF‐β1 (codon 10C/T, codon 25C/G) and IL‐10 (‐1082A/G) SNPs in 133 individuals from Ouangolodougou, a rural village in Northern Ivory Coast, where malaria and other parasitic diseases are endemic. The SNPs alleles were determined by ARMS‐PCR methodology. Allele frequencies of the SNPs investigated were as follows: IL 10 ‐1082G = 0.741 and ‐1082A = 0.259; TGF‐β1 Codon 10 C = 0.835 and T = 0.165; TGF‐β1 Codon 25 G = 0.782 and C = 0.218. For the TNF‐α gene, we found high frequencies of the ‐308A allele (0.305) and heterozygote genotypes (0.594), with a consequent deviation from the Hardy–Weinberg equilibrium. The high heterozygosity at the TNF‐α locus suggests a possible selective advantage of the heterozygote genomes, associated with intermediate levels of TNF‐α expression, against the infectious agents endemic in Western Africa.

Chromosomal aberrations in cultured human lymphocytes treated with the fungicide Thiram

In vitro effects of different concentrations of Thiram were tested on human lymphocytes to determine, by means of the chromosome aberrations (CAs) assay, whether this fungicide could induce clastogenic damage. Evidences of the effect of Thiram on human lymphocytes were limited to sister chromatid exchange, micronuclei formation, and comet assays. We evaluated 0.01, 0.1, 1.2, and 12.0 μg/mL of Thiram, where 0.01 μg/mL represent the acceptable daily intake dose set by the World Health Organization and the Food and Agriculture Organization for fruit and vegetables, whereas 0.1, 1.2, and 12.0 μg/mL are its multiple values. Results indicated that human lymphocytes treated in vitro with Thiram at concentrations of 1.20 and 12.0 μg/mL significantly increased CAs frequency, compared with the negative control, whereas at lower concentrations (0.01 and 0.1 μg/mL), this effect was not observed. However, Thiram showed a clastogenic effect also at the concentration value of 1.2 μg/mL that represents a lower value with respect to the residue limits found in Italy for grapes, strawberries, potatoes, tobacco, and other fruits and vegetables. Finally, according to some evidence obtained from the study of other fungicides, Thiram produced a significant reduction in the mitotic index with increasing concentration.

Baseline frequency of chromosomal aberrations and sister chromatid exchanges in peripheral blood lymphocytes of healthy individuals living in Turin (North-Western Italy): assessment of the effects of age, sex and GSTs gene polymorphisms on the levels of genomic damage

Abstract Background: The increased exposure to environmental pollutants has led to the awareness of the necessity for constant monitoring of human populations, especially those living in urban areas. Aim: This study evaluated the background levels of genomic damage in a sample of healthy subjects living in the urban area of Turin (Italy). The association between DNA damage with age, sex and GSTs polymorphisms was assessed. Subjects and methods: One hundred and one individuals were randomly sampled. Sister Chromatid Exchanges (SCEs) and Chromosomal Aberrations (CAs) assays, as well as genotyping of GSTT1 and GSTM1 genes, were performed. Results: Mean values of SCEs and CAs were 5.137 ± 0.166 and 0.018 ± 0.002, respectively. Results showed age and gender associated with higher frequencies of these two cytogenetic markers. The eldest subjects (51–65 years) showed significantly higher levels of genomic damage than younger individuals. GSTs polymorphisms did not appear to significantly influence the frequencies of either markers. Conclusion: The CAs background frequency observed in this study is one of the highest reported among European populations. Turin is one of the most polluted cities in Europe in terms of air fine PM10 and ozone and the clastogenic potential of these pollutants may explain the high frequencies of chromosomal rearrangements reported here.