No abstract

Thyroid cancer (TC) is the most frequent endocrine malignancy, accounting however for only 1-2% of all human cancers, and the best-established risk factor for TC is radiation exposure, particularly during childhood. Since the BER pathway seems to play an important role in the repair of DNA damage induced by IR and other genotoxicants, we carried out a hospital-based case-control study in order to evaluate the potential modifying role of 6 BER polymorphisms on the individual susceptibility to non-familial TC in 109 TC patients receiving iodine-131, and 217 controls matched for age (± 2 years), gender and ethnicity. Our results do not reveal a significant involvement of XRCC1 Arg194Trp and Arg399Gln, OGG1 Ser326Cys, APEX1 Asp148Glu, MUTYH Gln335His and PARP1 Val762Ala polymorphisms on the individual susceptibility towards TC, mostly in agreement with the limited available evidence. By histological stratification analysis, we observed that the association between the presence of heterozygosity in the MUTYH Gln335His polymorphism and TC risk almost reached significance for the papillary subtype of TC. This was the first time that the putative association between this polymorphism and TC susceptibility was evaluated. However, since the sample size was modest, the possibility of a type I error should not be excluded and this result should, therefore, be interpreted with caution. More in depth studies involving larger populations should be pursued in order to further clarify the potential usefulness of the MUTYH Gln335His genotype as a predictive biomarker of susceptibility to TC and the role of the remaining BER polymorphisms on TC susceptibility.

Formaldehyde (FA) is a commonly used chemical in anatomy and pathology laboratories as a tissue preservative and fixative. Because of its sensitising properties, irritating effects and cancer implication, FA accounts probably for the most important chemical-exposure hazard concerning this professional group. Evidence for genotoxic effects and carcinogenic properties in humans is insufficient and conflicting, particularly in regard to the ability of inhaled FA to induce toxicity on other cells besides first contact tissues, such as buccal and nasal cells. To evaluate the effects of exposure to FA in human peripheral blood lymphocytes, a group of 84 anatomy pathology laboratory workers exposed occupationally to FA and 87 control subjects were tested for chromosomal aberrations (CAs) and DNA damage (comet assay). The level of exposure to FA in the workplace air was evaluated. The association between genotoxicity biomarkers and polymorphic genes of xenobiotic-metabolising and DNA repair enzymes were also assessed. The estimated mean level of FA exposure was 0.38±0.03 ppm. All cytogenetic endpoints assessed by CAs test and comet assay % tail DNA (%TDNA) were significantly higher in FA-exposed workers compared with controls. Regarding the effect of susceptibility biomarkers, results suggest that polymorphisms in CYP2E1 and GSTP1 metabolic genes, as well as, XRCC1 and PARP1 polymorphic genes involved in DNA repair pathways are associated with higher genetic damage in FA-exposed subjects. Data obtained in this study show a potential health risk situation of anatomy pathology laboratory workers exposed to FA (0.38 ppm). Implementation of security and hygiene measures may be crucial to decrease risk. The obtained information may also provide new important data to be used by health care programs and by governmental agencies responsible for occupational health and safety.

The aim of this study was to analyse the prevalence of barriers to physical activity (PA) among adults according to the gender and socioeconomic status (SES). A total of 2236 subjects (927 men, 1309 women) aged between 30 and 50 y (M = 42±5 y) participated in the study. The data was collected through a questionnaire. Qui-square tests were performed to analyse the differences between genders and SES on perceived barriers. Significance level was p <0.05. Only 31% (32% male, 31% female) achieved the current PA recommendation. The most cited barriers were lack of time (55%), costs (20%), the desire to do other things (15%), the failure to consider themselves as athletes (15%) and lack of infrastructures near where they live. All other reasons were mentioned by less than 10% of the individuals tested. Among the most cited barriers, women reported costs more than men (12% male vs 25% female, p<0.001). On the other hand, men reported more often the lack of infrastructures in the neighbourhood (14% male, 9% female, p<0.001). In all of the most cited barriers there were significant differences between subjects with low and high SES. The barriers most associated with prevalence of inactivity among those with low SES were the failure to consider themselves as athletes (p<0.001), the costs (p<0.001), no time to practise (p=0.002) and the lack of infrastructures (p=0.002). The subjects with higher SES cited more often the desire to do other things. Women reported more often the barriers for PA in general, with big prevalence in the costs. Man, who practices informal PA more easily, reported more often the lack of infrastructures in the neighbourhood. Perceived barrier for PA were more prevalent in subjects with low SES. However, lack of time was a barrier most cited by men and women with high or low SES.