Stylianos M. Piperakis

DNA damage in a human population affected by chronic psychogenic stress

The effects of chronic psychogenic stress on the expression of DNA damage and cellular response to the damage were investigated. Using the comet assay, basal DNA damage was found to be similar in lymphocytes of both affected and non-affected populations (n = 30 in both groups). The induction of DNA damage in lymphocytes by external factors (H2O2 and gamma-irradiation), was also investigated. In these studies, cells were treated with 50, 100 and 150 microM H2O2 for 5 minutes or with 0.8, 2.5 and 4.2 Gy gamma-rays. A significant difference was found between the chronically stressed and the control populations, indicating the enhanced sensitivity of the former population. Cells were also held for 2 hours after the treatment, allowing time for the cells to deal with the induced DNA damage. Based on the level of residual DNA strand breaks, cells from the stressed population had more breaks than the controls. Gender does not alter these findings. In conclusion, our data indicate that cells from the stressed population were more sensitive to the induction of DNA damage and had higher level of residual damage. Therefore, stress conditions may cause the affected individuals to be susceptible to environmental mutagenic agents.

Investigation of the genotoxic effect of pesticides on greenhouse workers' lymphocytes.

In the present study, the genotoxic effects of commonly applied pesticides were evaluated using the alkaline comet assay (pH > 13). The amount of DNA damage (% DNA in tail) in peripheral lymphocytes of 49 male agricultural workers from Southern Poland were measured and compared to 50 men from the same area who had no previous occupational exposure to pesticides. No statistically significant differences in basal DNA damage were found between the study groups. In addition, exposure of peripheral blood lymphocytes to hydrogen peroxide (100 and 150 μM) or γ‐irradiation (2.5 or 4.2 Gy) led to a similar degree of additional DNA damage and subsequent repair (for 2 hr) for all studied populations. In conclusion, our results indicate that the greenhouse workers who participated in this study had no detectable increased DNA damage or alteration in their cellular response to DNA damage in comparison to our control population. Environ. Mol. Mutagen., 2009.

Effects of Pesticides on Occupationally Exposed Humans

Pesticides are known to contain numerous genotoxic compounds; however, genotoxicity biomonitoring studies of workers occupationally exposed to pesticides have produced variable results. In this study, we employed the Comet assay to examine DNA damage in peripheral blood lymphocytes (PBLs) from 64 greenhouse workers from Almería in south-eastern Spain in comparison to PBLs from 50 men from the same area but not engaged in any agricultural work. The results indicated that there were no differences in the basal levels of DNA damage in the two study groups. In addition, exposure of PBL from the workers and controls to hydrogen peroxide or γ-irradiation led to similar levels of DNA damage; the subsequent repair of the induced DNA damage was also similar for both study populations. Smoking had no impact on any of the responses. The results of this study indicate that the greenhouse workers had no detectable increase in DNA damage or alteration in the cellular response to DNA damage compared to our control population.

Understanding Nutrition: A Study of Greek Primary School Children Dietary Habits, Before and After Classroom Nutrition Intervention

The purpose of this study was first to assess and then to improve the diet of Greek primary school children teaching them healthy dietary habits and instructing them to face critically advertisements and media projected dietary models using a program which included intervention on cognitive, emotional, and social level. The results show that our intervention was more effective on the cognitive level and in particular on childrens ability to estimate the dietary value of different kinds of food. However, their food preferences were not affected significantly, suggesting that these are more resistant to change since they are already consolidated and, therefore, need longer intervention.

Understanding Greek Primary School Children's Comprehension of Sun Exposure.

The purpose of this study was to assess Greek primary (1st to 6th grade) school childrens understanding of sun exposure during summer vacation. Our results show that children know the damaging effects of long time exposure and the precautions that should be taken during sun bathing (sun glasses, hat, umbrella, sunscreen, etc). Nevertheless, they do not seem to avoid being exposed between 12.00 A.M. and 15.00 P.M., which is the most dangerous time. The socioeconomic status of father has no effect on the attitude of children towards taking protection measures when exposed to the sun, however, the educational status of the mother appears to influence childrens reported knowledge and behaviour. Place of residence (urban or rural areas) and gender does not influence their knowledge on the suns damaging effects and the precautions they should take. Finally, as children grow older they seem to gradually reduce the protective measures they take.

A survey on the knowledge, attitude and behavior of Greek elementary school students about oral health and dental care

Abstract The objective of this study was to evaluate the knowledge, attitude and behavior of Greek elementary school students in terms of oral health and dental care. Data on students’ oral health and dental treatment as well as, the factors that define these variables were collected and evaluated by a self-administered questionnaire for a sample of 595 students. The results revealed that irregular brushing was common. Apart from the use of toothbrush and toothpaste, extra aids for oral hygiene were also in use. The role of parents in supervising the oral hygiene habits of their children was concentrated only in giving advice. The students knew the causes of gingivitis and caries and how to protect their dental health. Also, they were aware of the mouth and dental structure on the general body health. Toothache was the driving reason of visiting the dentist. Irregular visits to the dentist were mentioned, even though they knew the importance of regular dental visits. The feeling of fear, in general, and fear of dental tools and dental wheel were referred to be the main reason for not visiting the dentist on a regular basis. Students were not encouraged by their parents for regular dental visits. The outcomes of this study show that Greek elementary students knowledge, attitude and behavior towards oral health and dental care need to be improved through oral health behavior programs.